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Find video protocols related to scientific articles indexed in Pubmed.
Radioiodo-DPA-713 Imaging Correlates with Bactericidal Activity of Tuberculosis Treatments in Mice.
Antimicrob. Agents Chemother.
PUBLISHED: 11-19-2014
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Current tools for monitoring response to tuberculosis treatments have several limitations. Noninvasive biomarkers could accelerate tuberculosis drug development and clinical studies, but to date little progress has been made in developing new imaging technologies for this application. In this study, we developed pulmonary iodo-DPA-713 single-photon emission computed tomography (SPECT) to serially monitor the activity of tuberculosis treatments in live mice, which develop necrotic granulomas and cavitary lesions. C3HeB/FeJ mice were aerosol infected with Mycobacterium tuberculosis and administered either a standard or a highly active bedaquiline containing drug regimen. Serial [(125)I]DPA-713 SPECT imaging was compared with [(18)F]fluorodeoxyglucose (FDG) positron emission tomography (PET) and standard microbiology. Ex vivo studies were performed to characterize and correlate DPA-713 imaging with cellular and cytokine responses. Pulmonary [(125)I]DPA-713 SPECT, but not [(18)F]FDG PET, was able to correctly identify the bactericidal activities of the two tuberculosis treatments as early as four weeks after starting treatment (P < 0.03). DPA-713 readily penetrated the fibrotic rims of necrotic and cavitary lesions. A time dependent decrease in both TNF-? and IFN-? levels was observed with treatments, with [(125)I]DPA-713 SPECT correlating best with tissue TNF-? levels (? = 0.94; P < 0.01). [(124)I]DPA-713 was also evaluated as a PET probe and demonstrated a 4.0-fold higher signal intensity in the infected tuberculous lesions compared to uninfected controls (P = 0.03). These studies provide proof-of-concept for application of a novel noninvasive imaging biomarker to monitor tuberculosis treatments, with potential for translation to humans.
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Imaging Enterobacteriaceae infection in vivo with 18F-fluorodeoxysorbitol positron emission tomography.
Sci Transl Med
PUBLISHED: 10-24-2014
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The Enterobacteriaceae are a family of rod-shaped Gram-negative bacteria that normally inhabit the gastrointestinal tract and are the most common cause of Gram-negative bacterial infections in humans. In addition to causing serious multidrug-resistant, hospital-acquired infections, a number of Enterobacteriaceae species are also recognized as biothreat pathogens. As a consequence, new tools are urgently needed to specifically identify and localize infections due to Enterobacteriaceae and to monitor antimicrobial efficacy. In this report, we used commercially available 2-[(18)F]-fluorodeoxyglucose ((18)F-FDG) to produce 2-[(18)F]-fluorodeoxysorbitol ((18)F-FDS), a radioactive probe for Enterobacteriaceae, in 30 min. (18)F-FDS selectively accumulated in Enterobacteriaceae, but not in Gram-positive bacteria or healthy mammalian or cancer cells in vitro. In a murine myositis model, (18)F-FDS positron emission tomography (PET) rapidly differentiated true infection from sterile inflammation with a limit of detection of 6.2 ± 0.2 log10 colony-forming units (CFU) for Escherichia coli. Our findings were extended to models of mixed Gram-positive and Gram-negative thigh co-infections, brain infection, Klebsiella pneumonia, and mice undergoing immunosuppressive chemotherapy. This technique rapidly and specifically localized infections due to Enterobacteriaceae, providing a three-dimensional holistic view within the animal. Last, (18)F-FDS PET monitored the efficacy of antimicrobial treatment, demonstrating a PET signal proportionate to the bacterial burden. Therapeutic failures associated with multidrug-resistant, extended-spectrum ?-lactamase (ESBL)-producing E. coli infections were detected in real time. Together, these data show that (18)F-FDS is a candidate imaging probe for translation to human clinical cases of known or suspected infections owing to Enterobacteriaceae.
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Mycobacterium tuberculosis dysregulates MMP/TIMP balance to drive rapid cavitation and unrestrained bacterial proliferation.
J. Pathol.
PUBLISHED: 09-04-2014
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Active tuberculosis (TB) often presents with advanced pulmonary disease, including irreversible lung damage and cavities. Cavitary pathology contributes to antibiotic failure, transmission, morbidity and mortality. Matrix metalloproteinases (MMPs), in particular MMP-1, are implicated in TB pathogenesis. We explored the mechanisms relating MMP/TIMP imbalance to cavity formation in a modified rabbit model of cavitary TB. Our model resulted in consistent progression of consolidation to human-like cavities (100% by day 28), with resultant bacillary burdens (>10(7) CFU/g) far greater than those found in matched granulomatous tissue (10(5) CFU/g). Using a novel, breath-hold computed tomography (CT) scanning and image analysis protocol, we showed that cavities developed rapidly from areas of densely consolidated tissue. Radiological change correlated with a decrease in functional lung tissue, as estimated by changes in lung density during controlled pulmonary expansion (R(2) ?=?0.6356, p < 0.0001). We demonstrated that the expression of interstitial collagenase (MMP-1) was specifically greater in cavitary compared to granulomatous lesions (p < 0.01), and that TIMP-3 significantly decreased at the cavity surface. Our findings demonstrated that an MMP-1/TIMP imbalance is associated with the progression of consolidated regions to cavities containing very high bacterial burdens. Our model provided mechanistic insight, correlating with human disease at the pathological, microbiological and molecular levels. It also provided a strategy to investigate therapeutics in the context of complex TB pathology. We used these findings to predict a MMP/TIMP balance in active TB and confirmed this in human plasma, revealing the potential of MMP/TIMP levels as key components of a diagnostic matrix aimed at distinguishing active from latent TB (PPV = 92.9%, 95% CI 66.1-99.8%, NPV = 85.6%; 95% CI 77.0-91.9%). Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
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In Vivo Prediction of Tuberculosis-Associated Cavity Formation in Rabbits.
J. Infect. Dis.
PUBLISHED: 08-12-2014
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The presence of cavitary lesions in patients with tuberculosis poses a significant clinical concern due to the risk of infectivity and the risk of antibiotic treatment failure. We describe 2 algorithms that use noninvasive positron emission tomography (PET) and computed tomography (CT) to predict the development of cavitary lesions in rabbits. Analysis of the PET region of interest predicted cavitary disease with 100% sensitivity and 76% specificity, and analysis of the CT region of interest predicted cavitary disease with 83.3% sensitivity and 76.9% specificity. Our results show that restricting our analysis to regions with high [(18)F]-fluorodeoxyglucose uptake provided the best combination of sensitivity and specificity.
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Imaging the evolution of reactivation pulmonary tuberculosis in mice using 18F-FDG PET.
J. Nucl. Med.
PUBLISHED: 07-31-2014
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Latent tuberculosis infection affects one third of the world's population and can reactivate (relapse) decades later. However, current technologies, dependent on postmortem analyses, cannot follow the temporal evolution of disease.
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Herbal antioxidant in clinical practice: a review.
Asian Pac J Trop Biomed
PUBLISHED: 07-06-2014
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Antioxidant-the word itself is magic. Using the antioxidant concept as a spearhead in proposed mechanisms for staving off so-called "free-radical" reactions, the rush is on to mine claims for the latest and most effective combination of free-radical scavenging compounds. We must acknowledge that such "radicals" have definitively been shown to damage all biochemical components such as DNA/RNA, carbohydrates, unsaturated lipids, proteins, and micronutrients such as carotenoids (alpha and beta carotene, lycopene), vitamins A, B6, B12, and folate. Defense strategies against such aggressive radical species include enzymes, antioxidants that occur naturally in the body (glutathione, uric acid, ubiquinol-10, and others) and radical scavenging nutrients, such as vitamins A, C, and E, and carotenoids. This paper will present a brief discussion of some well- and little-known herbs that may add to the optimization of antioxidant status and therefore offer added preventive values for overall health. It is important to state at the outset that antioxidants vary widely in their free-radical quenching effects and each may be individually attracted to specific cell sites. Further evidence of the specialized nature of the carotenoids is demonstrated by the appearance of two carotenoids in the macula region of the retina where beta-carotene is totally absent.
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Aceclofenac-loaded chondroitin sulfate conjugated SLNs for effective management of osteoarthritis.
J Drug Target
PUBLISHED: 06-23-2014
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Abstract Background: In intra-articular drug delivery, there are number of shortcomings such as lymphatic drainage from the synovial cavity, frequent dosing, adverse side effects and patient discomfort in the management of osteoarthritis (OA).
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Multidrug resistant Shigella flexneri : a rare case of septicemia in an infant.
J Clin Diagn Res
PUBLISHED: 06-20-2014
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Shigellosis is still an important public health problem in developing and under-developed countries. It may lead to rare but potentially fatal various extra intestinal complications like septicemia, involvement of CNS, urinary tract and liver especially in young malnourished children. The disease is difficult to prevent as only few bacteria are required for causing infection and there is increasing infection with multi drug resistant strains. A 6-month-old infant developed septicemia caused by multi drug resistant Shigella flexneri during an episode of gastrointestinal infection. The patient was managed in the emergency ward but unfortunately the infant expired. Considering septic shock, blood culture, stool culture and other relevant investigations were done. Stool as well as blood culture yielded Shigella flexneri. The isolates were multidrug resistant. Following is a rare case presentation of Shigella septicemia with severe shock, DIC and convulsions. The case report demonstrates how shigellosis can lead to a rare life threatening complication and hence should be considered as a possibility in septicemia associated with diarrhea and vomiting in infant and young children.
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Nuclear imaging: A powerful novel approach for tuberculosis.
Nucl. Med. Biol.
PUBLISHED: 05-29-2014
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Nearly 20years after the World Health Organization declared tuberculosis (TB) a global public health emergency, TB still remains a major global threat with 8.6 million new cases and 1.3 million deaths annually. Mycobacterium tuberculosis adapts to a quiescent physiological state, and is notable for complex interaction with the host, producing poorly-understood disease states ranging from latent infection to fully active disease. Of the approximately 2.5 billion people latently infected with M. tuberculosis, many will develop reactivation disease (relapse), years after the initial infection. While progress has been made on some fronts, the alarming spread of multidrug-resistant, extensively drug-resistant, and more recently totally-drug resistant strains is of grave concern. New tools are urgently needed for rapidly diagnosing TB, monitoring TB treatments and to allow unique insights into disease pathogenesis. Nuclear bioimaging is a powerful, noninvasive tool that can rapidly provide three-dimensional views of disease processes deep within the body and conduct noninvasive longitudinal assessments of the same patient. In this review, we discuss the application of nuclear bioimaging to TB, including the current state of the field, considerations for radioprobe development, study of TB drug pharmacokinetics in infected tissues, and areas of research and clinical needs that could be addressed by nuclear bioimaging. These technologies are an emerging field of research, overcome several fundamental limitations of current tools, and will have a broad impact on both basic research and patient care. Beyond diagnosis and monitoring disease, these technologies will also allow unique insights into understanding disease pathogenesis; and expedite bench-to-bedside translation of new therapeutics. Finally, since molecular imaging is readily available for humans, validated tracers will become valuable tools for clinical applications.
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The Overlap and Distinction of Self-Reported Symptoms between Interstitial Cystitis/Bladder Pain Syndrome and Overactive Bladder: A Questionnaire Based Analysis.
J. Urol.
PUBLISHED: 05-27-2014
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We compared symptoms between interstitial cystitis/bladder pain syndrome and overactive bladder based on patient self-reported symptoms on validated questionnaires.
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Genome-wide association scan in north Indians reveals three novel HLA-independent risk loci for ulcerative colitis.
Gut
PUBLISHED: 05-20-2014
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Over 100 ulcerative colitis (UC) loci have been identified by genome-wide association studies (GWASs) primarily in Caucasians (CEUs). Many of them have weak effects on disease susceptibility, and the bulk of the heritability cannot be ascribed to these loci. Very little is known about the genetic background of UC in non-CEU groups. Here we report the first GWAS on UC in a genetically distinct north Indian (NI) population.
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Development of a transmission-blocking malaria vaccine: progress, challenges, and the path forward.
Vaccine
PUBLISHED: 04-25-2014
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New interventions are needed to reduce morbidity and mortality associated with malaria, as well as to accelerate elimination and eventual eradication. Interventions that can break the cycle of parasite transmission, and prevent its reintroduction, will be of particular importance in achieving the eradication goal. In this regard, vaccines that interrupt malaria transmission (VIMT) have been highlighted as an important intervention, including transmission-blocking vaccines that prevent human-to-mosquito transmission by targeting the sexual, sporogonic, or mosquito stages of the parasite (SSM-VIMT). While the significant potential of this vaccine approach has been appreciated for decades, the development and licensure pathways for vaccines that target transmission and the incidence of infection, as opposed to prevention of clinical malaria disease, remain ill-defined. This article describes the progress made in critical areas since 2010, highlights key challenges that remain, and outlines important next steps to maximize the potential for SSM-VIMTs to contribute to the broader malaria elimination and eradication objectives.
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Targeting liver cancer via ASGP receptor using 5-FU-loaded surface-modified PLGA nanoparticles.
J Microencapsul
PUBLISHED: 04-03-2014
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Liver cancer is widespread liver malignancy in the world, for an estimated one million deaths annually.
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Unusual fungal bodies in conventional cervical smears: Report of nine cases.
Diagn. Cytopathol.
PUBLISHED: 03-31-2014
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Candida spp have often been reported in cervical cytology, other fungal organisms are very rare in modern literature. We report nine cases of conventional cervical smears showing Penicillium, Aspergillus, and Cladosporium spp in healthy imunocompetent females. Penicillium spp seen in four out of nine smears, Cladosporium spp alone in three out of nine smears, and Cladosporium spp along with Aspergillus spp in two out of nine smears. A detail of these nine cases is presented with discussion on importance of these structures when observed in conventional cervical smears. Awareness of such contaminants is important to differentiate from true infection for relevant therapeutic implications. A systematic step-wise approach to such structures is also suggested. Diagn. Cytopathol. 2014. © 2014 Wiley Periodicals, Inc.
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Uncommon associations and catastrophic manifestation in Takayasu arteritis: an autopsy case report.
Cardiovasc. Pathol.
PUBLISHED: 03-28-2014
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Takayasu arteritis, a chronic inflammatory vasculitis affecting aorta and its major branches, is complicated by stenosis, occlusion, and aneurysm formation. The aneurysm formation and subsequent complications such as heart failure, aortic regurgitation, and aneurysm rupture can be fatal. The aortic aneurysm rupture is a rare and fatal complication with only a few cases reported in the English literature. The involvement of coronary artery in Takayasu occurs in about 10% patients, and the coronary artery aneurysm is the least common manifestation. Here, we describe a case of Takayasu arteritis with abdominal aortic aneurysm rupture and coronary artery aneurysm. This patient also had associated systemic inflammatory diseases like sarcoidosis and Hashimoto's thyroiditis.
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Genome-wide analysis of methotrexate pharmacogenomics in rheumatoid arthritis shows multiple novel risk variants and leads for TYMS regulation.
Pharmacogenet. Genomics
PUBLISHED: 03-04-2014
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Methotrexate (MTX) is the drug of first choice for the treatment of rheumatoid arthritis (RA), but is effective only in around 60% of the patients. Identification of genetic markers to predict response is essential for effective treatment within a critical window period of 6 months after diagnosis, but have been hitherto elusive. In this study, we used genome-wide genotype data to identify the potential risk variants associated with MTX (poor)response in a north Indian RA cohort.
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Claudin 1 and nephrin label cellular crescents in diabetic glomerulosclerosis.
Hum. Pathol.
PUBLISHED: 02-18-2014
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Cellular crescents are typically inflammatory and associated with rapidly progressive glomerulonephritis. Their pathogenesis involves glomerular basement membrane rupture due to circulating or intrinsic factors. Crescents associated with diabetic glomerulosclerosis are rarely reported. Furthermore, the nature of cells forming crescents in diabetes is unknown. To investigate the nature of crescents in diabetes, we examined renal biopsies from diabetic patients with nodular glomerulosclerosis and crescents (n = 2), diabetes without crescents (n = 5), nondiabetic renal biopsies (n = 3), and crescentic glomerulonephritis with inflammatory crescents (n = 5). Electron microscopy and confocal immunofluorescence analysis with antibodies against nephrin (a podocyte marker) and claudin 1 (parietal epithelial cell marker) were performed. Diabetic glomeruli with crescents contained a mixture of crescentic cells expressing either claudin 1 (11 ± 1.4 cells/glomerulus) or nephrin (5.5 ± 3.0 cells/glomerulus). Rare crescentic cells coexpressed nephrin and claudin 1 (2.5 ± 1.6 cells/glomerulus). In contrast, inflammatory crescents were almost exclusively composed of claudin 1-positive cells (25 ± 5.3 cells/glomerulus). Cells coexpressing claudin 1 and nephrin were absent in inflammatory crescents and all cases without crescents. Electron microscopy showed podocyte bridge formation between the glomerular basement membrane and parietal basement membrane but no glomerular basement membrane rupture as in inflammatory crescents. Crescents in diabetes may occur in diabetes in the absence of a secondary etiology and are composed of a mixture of parietal epithelial cells and visceral podocytes. Cells coexpressing parietal epithelial and podocyte markers suggest that parietal epithelial cells may transdifferentiate into podocytes in response to severe glomerular injury.
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Development of an immunoassay for the kidney-specific protein myo-inositol oxygenase, a potential biomarker of acute kidney injury.
Clin. Chem.
PUBLISHED: 01-31-2014
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Acute kidney injury (AKI) affects 45% of critically ill patients, resulting in increased morbidity and mortality. The diagnostic standard, plasma creatinine, is nonspecific and may not increase until days after injury. There is significant need for a renal-specific AKI biomarker detectable early enough that there would be a potential window for therapeutic intervention. In this study, we sought to identify a renal-specific biomarker of AKI.
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Staphylococcus aureus: Screening for Nasal Carriers in a Community Setting with Special Reference to MRSA.
Scientifica (Cairo)
PUBLISHED: 01-21-2014
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Introduction. Emergence of MRSA infections among previously healthy persons in community settings (without exposure to health care facilities) has been noted recently. MRSA infections are now classified as health care-associated MRSA (HA-MRSA) and community-associated MRSA (CA-MRSA) infections. Its colonization is an important risk factor for subsequent MRSA infection. Aims and Objectives. The aim was to screen patients and health care workers for staphylococcal carriage, identify risk factors for MRSA colonization, and determine the sensitivity pattern. Materials and Methods. A total of 200 subjects were screened for nasal carriage after obtaining verbal consent. These were both healthy subjects attending various outpatient departments and health care workers. Specimens were collected from the anterior nares using premoistened sterile cotton swabs and inoculated onto blood agar and mannitol salt agar and incubated at 37°C for 24-48?h. Results. Staphylococcus aureus colonisation was found to be 12% (n = 24). MRSA was identified in 5% (n = 10) which represents 41.66% of SA. A total of 10 strains of MRSA were isolated from 200 subjects, giving an overall positivity rate of 5%. Discussion. Staphylococcal colonization was found to be 12% (MRSA 5%). Fluoroquinolone resistance was remarkable whereas all strains were sensitive to vancomycin, teicoplanin, linezolid, quinupristin-dalfopristin.
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Validating single-cell genomics for the study of renal development.
Kidney Int.
PUBLISHED: 01-17-2014
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Single-cell genomics will enable studies of the earliest events in kidney development, although it is unclear if existing technologies are mature enough to generate accurate and reproducible data on kidney progenitors. Here we designed a pilot study to validate a high-throughput assay to measure the expression levels of key regulators of kidney development in single cells isolated from embryonic mice. Our experiment produced 4608 expression measurements of 22 genes, made in small cell pools, and 28 single cells purified from the RET-positive ureteric bud. There were remarkable levels of concordance with expression data generated by traditional microarray analysis on bulk ureteric bud tissue with the correlation between our average single-cell measurements and GUDMAP measurements for each gene of 0.82-0.85. Nonetheless, a major motivation for single-cell technology is to uncover dynamic biology hidden in population means. There was evidence for extensive and surprising variation in expression of Wnt11 and Etv5, both downstream targets of activated RET. The variation for all genes in the study was strongly consistent with burst-like promoter kinetics. Thus, our results can inform the design of future single-cell experiments, which are poised to provide important insights into kidney development and disease.
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An update on Ayurvedic herb Convolvulus pluricaulis Choisy.
Asian Pac J Trop Biomed
PUBLISHED: 01-16-2014
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Convolvulus pluricaulis Choisy (C. pluricaulis) is a perennial herb that seems like morning glory. All parts of the herb are known to possess therapeutic benefits. The plant is used locally in Indian and Chinese medicine to cure various diseases. It is used in Ayurvedic formulation for chronic cough, sleeplessness, epilepsy, hallucinations, anxiety etc. Based on the comprehensive review of plant profile, pharmacognosy, phytochemistry, pharmacological and toxicological data on the C. pluricaulis, there will be more opportunities for the future research and development on the herb C. pluricaulis. Information on the C. pluricaulis was collected via electronic search (using Pub Med, SciFinder, Google Scholar and Web of Science) and library search for articles published in peer-reviewed journals. Furthermore, information also was obtained from some local books on ethnopharmacology. This paper covers the literature, primarily pharmacological, from 1985 to the end of 2012. The C. pluricaulis is an important indigenous medicine, which has a long medicinal application for liver disease, epileptic disease, microbial disease, cytotoxic and viral diseases, central nervous system (CNS) disease in Ayurvedic medicine, traditional Chinese medicine and other indigenous medical systems. The isolated metabolites and crude extract have exhibited a wide of in vitro and in vivo pharmacological effect, including CNS depression, anxiolytic, tranquillizing, antidepressant, antistress, neurodegenerative, antiamnesic, antioxidant, hypolipidemic, immunomodulatory, analgesic, antifungal, antibacterial, antidiabetic, antiulcer, anticatatonic, and cardiovascular activity. A chemical study of this plant was then initiated, which led to the isolation of carbohydrats, proteins, alkaloids, fatty acids, steroids, coumarins, flavanoids, and glycosides as active chemicals that bring about its biological effects. A series of pharmacognostical studies of this plant show that it is a herb, its stem and leaves are hairy, more over it has two types of stomata, anisocytic and paracytic. A herb, C. pluricaulis has emerged as a good source of the traditional medicine for the treatment of liver disease, epileptic disease, microbial disease, cytotoxic and viral diseases, and CNS disease. Pharmacological results have validated the use of this species in traditional medicine. All the parts of the herb are known to possess therapeutic benefits. Expansion of research materials would provide more opportunities for the discovery of new bioactive principles from C. pluricaulis.
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Characterization of a novel necrotic granuloma model of latent tuberculosis infection and reactivation in mice.
Am. J. Pathol.
PUBLISHED: 01-07-2014
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We sought to develop and characterize a novel paucibacillary model in mice, which develops necrotic lung granulomas after infection with Mycobacterium tuberculosis. Six weeks after aerosol immunization with recombinant Mycobacterium bovis bacillus Calmette-Guerin overexpressing the 30-kDa antigen, C3HeB/FeJ mice were aerosol infected with M. tuberculosis H37Rv. Six weeks later, mice were treated with one of three standard regimens for latent tuberculosis infection or tumor necrosis factor (TNF)-neutralizing antibody. Mouse lungs were analyzed by histological features, positron emission tomography/computed tomography, whole-genome microarrays, and RT-PCR. Lungs and sera were studied by multiplex enzyme-linked immunosorbent assays. Paucibacillary infection was established, recapitulating the sterilizing activities of human latent tuberculosis infection regimens. TNF neutralization led to increased lung bacillary load, disrupted granuloma architecture with expanded necrotic foci and reduced tissue hypoxia, and accelerated animal mortality. TNF-neutralized mouse lungs and sera showed significant up-regulation of interferon ?, IL-1?, IL-6, IL-10, chemokine ligands 2 and 3, and matrix metalloproteinase genes. Clinical and microbiological reactivation of paucibacillary infection by TNF neutralization was associated with reduced hypoxia in lung granulomas and induction of matrix metalloproteinases and proinflammatory cytokines. This model may be useful for screening the sterilizing activity of novel anti-tuberculosis drugs, and identifying mycobacterial regulatory and metabolic pathways required for bacillary growth restriction and reactivation.
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F-18 FDG PET/CT in the evaluation of Takayasu arteritis: an experience from the tropics.
J Nucl Cardiol
PUBLISHED: 01-03-2014
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To evaluate the performance parameters of FDG PET/CT in patients with Takayasu arteritis at diagnosis and during immunosuppression.
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Scrub typhus is an under-recognized cause of acute febrile illness with acute kidney injury in India.
PLoS Negl Trop Dis
PUBLISHED: 01-01-2014
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Infection-related acute kidney injury (AKI) is an important preventable cause of morbidity and mortality in the tropical region. The prevalence and outcome of kidney involvement, especially AKI, in scrub typhus is not known. We investigated all patients with undiagnosed fever and multisystem involvement for scrub typhus and present the pattern of renal involvement seen.
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Computer-aided detection and quantification of cavitary tuberculosis from CT scans.
Med Phys
PUBLISHED: 12-11-2013
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Purpose: To present a computer-aided detection tool for identifying, quantifying, and evaluating tuberculosis (TB) cavities in the infected lungs from computed tomography (CT) scans.Methods: The authors proposed method is based on a novel shape-based automated detection algorithm on CT scans followed by a fuzzy connectedness (FC) delineation procedure. In order to assess interaction between cavities and airways, the authors first roughly identified air-filled structures (airway, cavities, esophagus, etc.) by thresholding over Hounsfield unit of CT image. Then, airway and cavity structure detection was conducted within the support vector machine classification algorithm. Once airway and cavities were detected automatically, the authors extracted airway tree using a hybrid multiscale approach based on novel affinity relations within the FC framework and segmented cavities using intensity-based FC algorithm. At final step, the authors refined airway structures within the local regions of FC with finer control. Cavity segmentation results were compared to the reference truths provided by expert radiologists and cavity formation was tracked longitudinally from serial CT scans through shape and volume information automatically determined through the authors proposed system. Morphological evolution of the cavitary TB were analyzed accordingly with this process. Finally, the authors computed the minimum distance between cavity surface and nearby airway structures by using the linear time distance transform algorithm to explore potential role of airways in cavity formation and morphological evolution.Results: The proposed methodology was qualitatively and quantitatively evaluated on pulmonary CT images of rabbits experimentally infected with TB, and multiple markers such as cavity volume, cavity surface area, minimum distance from cavity surface to the nearest bronchial-tree, and longitudinal change of these markers (namely, morphological evolution of cavities) were determined precisely. While accuracy of the authors cavity detection algorithm was 94.61%, airway detection part of the proposed methodology showed even higher performance by 99.8%. Dice similarity coefficients for cavitary segmentation experiments were found to be approximately 99.0% with respect to the reference truths provided by two expert radiologists (blinded to their evaluations). Moreover, the authors noted that volume derived from the authors segmentation method was highly correlated with those provided by the expert radiologists (R(2) = 0.99757 and R(2) = 0.99496, p < 0.001, with respect to the observer 1 and observer 2) with an interobserver agreement of 98%. The authors quantitatively confirmed that cavity formation was positioned by the nearby bronchial-tree after exploring the respective spatial positions based on the minimum distance measurement. In terms of efficiency, the core algorithms take less than 2 min on a linux machine with 3.47 GHz CPU and 24 GB memory.Conclusion: The authors presented a fully automatic method for cavitary TB detection, quantification, and evaluation. The performance of every step of the algorithm was qualitatively and quantitatively assessed. With the proposed method, airways and cavities were automatically detected and subsequently delineated in high accuracy with heightened efficiency. Furthermore, not only morphological information of cavities were obtained through the authors proposed framework, but their spatial relation to airways, and longitudinal analysis was also provided to get further insight on cavity formation in tuberculosis disease. To the authors best of knowledge, this is the first study in computerized analysis of cavitary tuberculosis from CT scans.
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Segmentation of PET Images for Computer-Aided Functional Quantification of Tuberculosis in Small Animal Models.
IEEE Trans Biomed Eng
PUBLISHED: 11-05-2013
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Pulmonary infections often cause spatially diffuse and multifocal radiotracer uptake in positron emission tomography (PET) images, which makes accurate quantification of the disease extent challenging. Image segmentation plays a vital role in quantifying uptake due to distributed nature of immuno-pathology and associated metabolic activities in pulmonary infection, specifically tuberculosis (TB). For this task, thresholding-based segmentation methods may be better suited over other methods; however, performance of the thresholding-based methods depend on the selection of thresholding parameters, which are often suboptimal. Several optimal thresholding techniques have been proposed in the literature, but there is currently no consensus on how to determine the optimal threshold for precise identification of spatially diffuse and multi-focal radiotracer uptake. In this study, we propose a method to select optimal thresholding levels by utilizing a novel intensity affinity metric within the Affinity Propagation clustering framework. We tested the proposed method against 70 longitudinal PET images of rabbits infected with TB. The overall dice similarity coefficient (DSC) between the segmentation from the proposed method and two expert segmentations was found to be 91:258:01% with a sensitivity of 88:8012:59% and a specificity of 96:019:20%. High accuracy and heightened efficiency of our proposed method, as compared to other PET image segmentation methods, were reported with various quantification metrics.
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Dopamine-dependent compensation maintains motor behavior in mice with developmental ablation of dopaminergic neurons.
J. Neurosci.
PUBLISHED: 10-25-2013
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The loss of dopaminergic neurons in the substantia nigra pars compacta (SNc) and consequent depletion of striatal dopamine are known to underlie the motor deficits observed in Parkinsons disease (PD). Adaptive changes in dopaminergic terminals and in postsynaptic striatal neurons can compensate for significant losses of striatal dopamine, resulting in preservation of motor behavior. In addition, compensatory changes independent of striatal dopamine have been proposed based on PD therapies that modulate nondopaminergic circuits within the basal ganglia. We used a genetic strategy to selectively destroy dopaminergic neurons in mice during development to determine the necessity of these neurons for the maintenance of normal motor behavior in adult and aged mice. We find that loss of 90% of SNc dopaminergic neurons and consequent depletion of >95% of striatal dopamine does not result in changes in motor behavior in young-adult or aged mice as evaluated by an extensive array of motor behavior tests. Treatment of aged mutant mice with the dopamine receptor antagonist haloperidol precipitated motor behavior deficits in aged mutant mice, indicating that <5% of striatal dopamine is sufficient to maintain motor function in these mice. We also found that mutant mice exhibit an exaggerated response to l-DOPA compared with control mice, suggesting that preservation of motor function involves sensitization of striatal dopamine receptors. Our results indicate that congenital loss of dopaminergic neurons induces remarkable adaptions in the nigrostriatal system where limited amounts of dopamine in the dorsal striatum can maintain normal motor function.
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The Med1 subunit of the mediator complex induces liver cell proliferation and is phosphorylated by AMP kinase.
J. Biol. Chem.
PUBLISHED: 08-13-2013
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Mediator, a large multisubunit protein complex, plays a pivotal role in gene transcription by linking gene-specific transcription factors with the preinitiation complex and RNA polymerase II. In the liver, the key subunit of the Mediator complex, Med1, interacts with several nuclear receptors and transcription factors to direct gene-specific transcription. Conditional knock-out of Med1 in the liver showed that hepatocytes lacking Med1 did not regenerate following either partial hepatectomy or treatment with certain nuclear receptor activators and failed to give rise to tumors when challenged with carcinogens. We now report that the adenovirally driven overexpression of Med1 in mouse liver stimulates hepatocyte DNA synthesis with enhanced expression of DNA replication, cell cycle control, and liver-specific genes, indicating that Med1 alone is necessary and sufficient for liver cell proliferation. Importantly, we demonstrate that AMP-activated protein kinase (AMPK), an important cellular energy sensor, interacts with, and directly phosphorylates, Med1 in vitro at serine 656, serine 756, and serine 796. AMPK also phosphorylates Med1 in vivo in mouse liver and in cultured primary hepatocytes and HEK293 and HeLa cells. In addition, we demonstrate that PPAR? activators increase AMPK-mediated Med1 phosphorylation in vivo. Inhibition of AMPK by compound C decreased hepatocyte proliferation induced by Med1 and also by the PPAR? activators fenofibrate and Wy-14,643. Co-treatment with compound C attenuated PPAR? activator-inducible fatty acid ?-oxidation in liver. Our results suggest that Med1 phosphorylation by its association with AMPK regulates liver cell proliferation and fatty acid oxidation, most likely as a downstream effector of PPAR? and AMPK.
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Pediatric tuberculosis in young children in India: a prospective study.
Biomed Res Int
PUBLISHED: 08-06-2013
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Background. India has one of the highest tuberculosis (TB) burdens globally. However, few studies have focused on TB in young children, a vulnerable population, where lack of early diagnosis results in poor outcomes. Methods. Young children (?5 years) with suspected TB were prospectively enrolled at a tertiary hospital in Pune, India. Detailed clinical evaluation, HIV testing, mycobacterial cultures, and drug susceptibility testing were performed. Results. 223 children with suspected TB were enrolled. The median age was 31 months, 46% were female, 86% had received BCG, 57% were malnourished, and 10% were HIV positive. 12% had TB disease (definite or probable), 35% did not have TB, while TB could not be ruled out in 53%. Extrapulmonary disease was noted in 46%, which was predominantly meningeal. Tuberculin skin test (TST) was positive in 20% of children with TB. Four of 7 (57%) children with culture-confirmed TB harbored drug-resistant (DR) strains of whom 2 (50%) were multi-DR (MDR). In adjusted analyses, HIV infection, positive TST, and exposure to household smoke were found to be significantly associated with children with TB (P ? 0.04). Mortality (at 1 year) was 3 of 26 (12%) and 1 of 79 (1%), respectively, in children with TB and those without TB (P < 0.05). Conclusions. Diagnosis of TB is challenging in young children, with high rates of extra-pulmonary and meningeal disease. While the data on DR-TB are limited by the small sample size, they are however concerning, and additional studies are needed to more accurately define the prevalence of DR strains in this vulnerable population.
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Bistability in a model of early B cell receptor activation and its role in tonic signaling and system tunability.
Mol Biosyst
PUBLISHED: 08-02-2013
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Activation of the antigen receptors on the surface of B cells in response to their cognate ligands is tightly controlled by feedback mechanisms. Apart from ligand induced signaling, B cell receptors (BCRs) emanate ligand independent tonic signaling crucial for B cell survival and development. In the absence of a ligand, BCR tonic signaling is controlled by the basal activity of the Src family protein tyrosine kinase Lyn and the protein tyrosine phosphatase SHP. The binding of an antigen to the BCR causes receptor clustering or aggregation which is one of the earliest events in B cell activation. Lyn binds to aggregated receptors and phosphorylates them. In turn phosphorylation enhances the stability of receptor clusters against dissociation into monomers as well as the binding of Lyn to the receptor clusters, thereby producing positive feedback loops that enhance receptor clustering and activation. Apart from Lyn mediated positive feedback loops, SHP and BCR aggregates mutually inhibit each other to form a double negative feedback loop. Here, we present a simple computational model of BCR proximal signaling that incorporates these multiple feedback loops between the three molecules BCR, Lyn and SHP and their complexes. The model predicts bistable behaviour in the system that explains both the tonic signaling and ligand mediated receptor activation and a range of other biological phenomena in a unified manner. We find the bistability to be highly tunable by changes in the protein levels while remaining sufficiently robust to changes in the rate constants. The nested architecture of multiple feedback loops enhances the robustness of the bistability. Our model explains the recent experimental observation of the lack of response of germinal center B cells to ligand stimulation in terms of the tunability of the bistable switch by modification of SHP levels.
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Noninvasive Molecular Imaging of Tuberculosis-Associated Inflammation With Radioiodinated DPA-713.
J. Infect. Dis.
PUBLISHED: 07-30-2013
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Background.?Increased expression of translocator protein (TSPO) is a feature of microglial and macrophage activation. Since activated macrophages are key components of tuberculosis-associated inflammation, we evaluated radioiodinated DPA-713, a synthetic ligand of TSPO, for in vivo imaging of host response. Methods.?Mice were infected with aerosolized Mycobacterium tuberculosis and evaluated using whole-body [(125)I]iodo-DPA-713 single-photon emission computed tomography (SPECT). Ex vivo biodistribution and correlative immunofluorescence studies were also performed. Results.?[(125)I]Iodo-DPA-713 SPECT imaging clearly delineated tuberculosis-associated pulmonary inflammation in live animals. Biodistribution studies confirmed radiotracer specificity for inflamed pulmonary tissues. Immunofluorescence studies demonstrated that TSPO is highly expressed in CD68(+) macrophages and phagocytic cells within tuberculosis lesions and that [(125)I]DPA-713 specifically accumulates within these cells. Coadministration of excess unlabelled DPA-713 abrogated both the SPECT and ex vivo fluorescence signals. Lesion-specific signal-to-noise ratios were significantly higher with [(125)I]iodo-DPA-713 SPECT (4.06 ± 0.52) versus [(18)F]fluorodeoxyglucose (FDG) positron emission tomography (PET) (2.00 ± 0.28) performed in the same mice (P = .004). Conclusions.?[(125)I]Iodo-DPA-713 accumulates specifically in tuberculosis-associated inflammatory lesions by selective retention within macrophages and phagocytic cells. [(125)I]Iodo-DPA-713 SPECT provides higher lesion-specific signal-to-noise ratios than [(18)F]FDG PET and may prove to be a more specific biomarker to monitor tuberculosis in situ.
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Development and Validation of the HPLC Method for Simultaneous Estimation of Paclitaxel and Topotecan.
J Chromatogr Sci
PUBLISHED: 07-10-2013
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A simple, rapid, accurate and precise high performance liquid chromatography (HPLC) method for simultaneous analysis of Paclitaxel and Topotecan was developed. Different analytical parameters, such as linearity, accuracy, precision, specificity with intentional degradation, limit of detection and limit of quantification (LOQ), were determined according to the ICH guidelines. Acetonitrile-water (70:30, 0.1% trifluoroacetic acid) was run on a Phenomenex Luna C-18(2) column in isocratic mode at a flow rate of 1.2 mL/min for simultaneous analysis of the two drugs using a UV detector set at 227 nm. The proposed method showed a retention time (Rt) of 14.56 min for Topotecan and 23.81 min for Paclitaxel with a continuous run up to 30 min. The linearity of the calibration curves for each analyte in the desired concentration range was found to be good (r(2) > 0.9995). The recovery ranged from 97.9 to 101% for each drug with a relative standard deviation (%RSD) of <2%. Peaks corresponding to each of the drugs exhibited  positive values for the minimum peak purity index over the entire range of integrated chromatographic peak indicating high purity of the peaks. Stability analysis revealed that the drugs remained stable for sufficient time. Thus, the developed method was found to be robust and it can be employed to quantify Paclitaxel and Topotecan in commercial sample and rat blood/serum.
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Metabotropic glutamate receptors: a review on prospectives and therapeutic aspects.
Mini Rev Med Chem
PUBLISHED: 07-06-2013
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The metabotropic glutamate (mGluRs) receptors are a distinct class of G-protein-coupled receptors that act through activation of phospholipase C and/or inhibition of adenylate cyclase. They encompass seven-transmembrane domain proteins, comprehensively expressed in neuronal and glial cells within the brain, spinal cord and periphery and are involved in controlling pathophysiology of a number of diseases. These receptors may be sorted into three groups based on similarity of amino acid sequence, pharmacology and the transducer pathways they couple. The agonists and antagonists act at the N-terminal glutamate binding site and present a pharmacological strategy to modulate pathogenesis. A number of these compounds are positive or negative allosteric modulators that bind within the receptor transmembrane heptahelical domains. This imparts improved subtype selectivity, improved bioavailability and better drug like properties (e.g. CNS penetration). The mGluRs are presently the focal point of sizeable attention because of their potential as drug targets for the treatment of neurological and psychiatric disorders of the brain including Schizophrenia, Alzheimers disease, Parkinsons disease, addiction, anxiety, depression, epilepsy and pain. The present review focuses on signal transduction mechanisms implicated to control and functionally upregulate the glutamatergic transmission system. The article also hallmarks agonists and antagonists for mGluRs as pivotal agents to ameliorate an array of neurological and psychiatric disorders.
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Peptide and protein delivery using new drug delivery systems.
Crit Rev Ther Drug Carrier Syst
PUBLISHED: 05-14-2013
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Pharmaceutical and biotechnological research sorts protein drug delivery systems by importance based on their various therapeutic applications. The effective and potent action of the proteins/peptides makes them the drugs of choice for the treatment of numerous diseases. Major research issues in protein delivery include the stabilization of proteins in delivery devices and the design of appropriate target-specific protein carriers. Many efforts have been made for effective delivery of proteins/peptidal drugs through various routes of administrations for successful therapeutic effects. Nanoparticles made of biodegradable polymers such as poly lactic acid, polycaprolactone, poly(lactic-co-glycolic acid), the poly(fumaric-co-sebacic) anhydride chitosan, and modified chitosan, as well as solid lipids, have shown great potential in the delivery of proteins/peptidal drugs. Moreover, scientists also have used liposomes, PEGylated liposomes, niosomes, and aquasomes, among others, for peptidal drug delivery. They also have developed hydrogels and transdermal drug delivery systems for peptidal drug delivery. A receptor-mediated delivery system is another attractive strategy to overcome the limitation in drug absorption that enables the transcytosis of the protein across the epithelial barrier. Modification such as PEGnology is applied to various proteins and peptides of the desired protein and peptides also increases the circulating life, solubility and stability, pharmacokinetic properties, and antigenicity of protein. This review focuses on various approaches for effective protein/peptidal drug delivery, with special emphasis on insulin delivery.
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Management of drug induced sexual dysfunction in male rats by ethyl acetate fraction of onion.
Acta Pol Pharm
PUBLISHED: 04-26-2013
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The present study aimed to investigate the effect of ethyl acetate fraction of A. cepa bulb on mating behavior in paroxetine-induced sexually dysfunction male rats. Sexual dysfunctions such as decreased libido, delayed orgasm, difficulties in maintaining an erection, and inhibition of ejaculation are common side effects of paroxetine. A. cepa bulb ethyl acetate fraction (200 mg/kg) was administered orally in paroxetine-induced sexually impaired male rats for 7 days. At the end of 7th day, mount frequency (MF), intromission frequency (IF), ejaculatory frequency (EF), mount latency (ML), intromission latency (IL), ejaculatory latency (EL) and post-ejaculatory interval (PEI) were the parameters observed. Results showed that in relation to the paroxetine treated group, ethyl acetate fraction, significantly restored the normal sexual behavior as evident from increased MF, IF, EF and reduced ML, IL, EL and PEI.
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Distribution of HLA-A, B and DRB1 alleles in Sahariya tribe of North Central India: An association with pulmonary tuberculosis.
Infect. Genet. Evol.
PUBLISHED: 04-17-2013
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Sahariya, a primitive tribe, native of North Central India, is characterized by a significantly increased incidence of pulmonary tuberculosis (PTB) as compared to other tribes from the same region. Host genetic factors are known to influence susceptibility to PTB at the population level. Since an association of immune regulatory genes, particularly HLA, with PTB susceptibility has already been reported in several studies, we investigated a similar association of HLA alleles with PTB pathogenesis in the Sahariya tribe. A total of 210 cases and 178 healthy individuals from Sahariya tribe were genotyped for HLA class I and II alleles using the PCR based SSP and Reverse-SSO methods. The study showed a significantly increased allelic frequency of HLA-DRB1(?)15 (p=0.02) in the patients as compared to healthy controls. However, the allelic frequency of HLA-DRB1(?)16 was significantly reduced in patients than in controls (p=0.01). Three locus haplotype analysis of HLA-A, B and DR revealed a significantly increased frequency of A(?)24-B(?)40-DRB1(?)15 haplotype among patients than controls (p=0.005), while A(?)02-B(?)40-DRB1(?)16 and A(?)02-B40-DRB1(?)03 (p=0.001 and 0.02, respectively) were significantly reduced in the patients. Our findings confirm a positive association of HLA-DRB1(?)15 in Sahariya tribe similar to the one already shown in other Indian ethnic groups. On the other hand, HLA-A(?)24-B(?)40-DRB1(?)15 haplotype was found to be specific to Sahariya tribe with a strong predisposition to PTB. Further, the protection offered by DRB1(?)16 allele and associated haplotypes towards PTB in this tribe appears to be a novel finding that warrants further investigation with regard to resistance to PTB.
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Formulation and optimization of temozolomide nanoparticles by 3 factor 2 level factorial design.
Biomatter
PUBLISHED: 04-01-2013
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The aim of this study was to investigate the combined influence of 3 independent variables in the preparation of temozolomide bearing Non-PEGylated and PEGylated nanoparticles by emulsification solvent evaporation method. A 3 factor 2 level design was used to derive a polynomial quadratic model and construct contour plots to predict responses. The independent variables selected were concentration of drug (A), concentration of PLGA/PEG-PLGA (B), PVA concentration in aqueous phase (C) and sonication time (D) and evaluated for percentage drug entrapment (PDE) and particle size (PS). A 3 ( 4) factorial design was used with 4 factors (A, B, C and D) at 3 levels and experimental trials were performed at all 82 possible combinations. In the present work, 28 runs are considered as the preliminary trials revealed that on increasing drug concentration from 2.5 to 5 mg the percent drug entrapment increases, but on further increasing the drug concentration (i.e., to 7.5 mg) no significant effect on the percent drug entrapment and particle size was observed. The 3 ( 4) factorial design was used to derive a polynomial quadratic model and construct contour plots to predict responses. Contour plots were constructed to show the effects of A, B, C and D on the PDE and PS.
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A computational pipeline for quantification of pulmonary infections in small animal models using serial PET-CT imaging.
EJNMMI Res
PUBLISHED: 03-27-2013
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Infectious diseases are the second leading cause of death worldwide. In order to better understand and treat them, an accurate evaluation using multi-modal imaging techniques for anatomical and functional characterizations is needed. For non-invasive imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI), and positron emission tomography (PET), there have been many engineering improvements that have significantly enhanced the resolution and contrast of the images, but there are still insufficient computational algorithms available for researchers to use when accurately quantifying imaging data from anatomical structures and functional biological processes. Since the development of such tools may potentially translate basic research into the clinic, this study focuses on the development of a quantitative and qualitative image analysis platform that provides a computational radiology perspective for pulmonary infections in small animal models. Specifically, we designed (a) a fast and robust automated and semi-automated image analysis platform and a quantification tool that can facilitate accurate diagnostic measurements of pulmonary lesions as well as volumetric measurements of anatomical structures, and incorporated (b) an image registration pipeline to our proposed framework for volumetric comparison of serial scans. This is an important investigational tool for small animal infectious disease models that can help advance researchers understanding of infectious diseases.
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Flux-based classification of reactions reveals a functional bow-tie organization of complex metabolic networks.
Phys Rev E Stat Nonlin Soft Matter Phys
PUBLISHED: 03-23-2013
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Unraveling the structure of complex biological networks and relating it to their functional role is an important task in systems biology. Here we attempt to characterize the functional organization of the large-scale metabolic networks of three microorganisms. We apply flux balance analysis to study the optimal growth states of these organisms in different environments. By investigating the differential usage of reactions across flux patterns for different environments, we observe a striking bimodal distribution in the activity of reactions. Motivated by this, we propose a simple algorithm to decompose the metabolic network into three subnetworks. It turns out that our reaction classifier, which is blind to the biochemical role of pathways, leads to three functionally relevant subnetworks that correspond to input, output, and intermediate parts of the metabolic network with distinct structural characteristics. Our decomposition method unveils a functional bow-tie organization of metabolic networks that is different from the bow-tie structure determined by graph-theoretic methods that do not incorporate functionality.
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A new horizon in modifications of chitosan: syntheses and applications.
Crit Rev Ther Drug Carrier Syst
PUBLISHED: 03-21-2013
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Chitosan is a naturally occurring biopolymer having diversified applications not only in the pharmaceutical field, but also in the biomedical profession. The presence of functional groups, i.e., hydroxyl, acetamido, and amine in the chitosan parent backbone, makes it a suitable candidate for chemical modification, and introduces desired physicochemical and biochemical properties, without any changes in its fundamental skeleton. The various modifications, i.e., alkylation, acylation, quaternization, hydroxyalkylation, carboxyalkylation, thiolation, sulfation, phosphorylation, enzymatic modifications, oligomerization, and graft copolymerization with assorted modifications, and their pharmaceutical and biomedical applications, are discussed in this article. Additionally, it is also limelighted how the chemically engineered chitosan has established a better place with regard to the vista of applications in the arena of sciences such as pharmaceutical, biomedical, biotechnological, tissue engineering, the textile industry, chemistry, the food industry, and many more. This review, hopefully, could enrich knowledge and bring forth new thoughts in line with progress in chitosan polymer science.
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Stage specific requirement of Gfr?1 in the ureteric epithelium during kidney development.
Mech. Dev.
PUBLISHED: 03-16-2013
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Glial cell line-derived neurotrophic factor (GDNF) binds a coreceptor GDNF family receptor ?1 (GFR?1) and forms a signaling complex with the receptor tyrosine kinase RET. GDNF-GFR?1-RET signaling activates cellular pathways that are required for normal induction of the ureteric bud (UB) from the Wolffian duct (WD). Failure of UB formation results in bilateral renal agenesis and perinatal lethality. Gfr?1 is expressed in both the epithelial and mesenchymal compartments of the developing kidney while Ret expression is specific to the epithelium. The biological importance of Gfr?1s wider tissue expression and its role in later kidney development are unclear. We discovered that conditional loss of Gfr?1 in the WD epithelium prior to UB branching is sufficient to cause renal agenesis. This finding indicates that Gfr?1 expressed in the nonepithelial structures cannot compensate for this loss. To determine Gfr?1s role in branching morphogenesis after UB induction we used an inducible Gfr?1-specific Cre-deletor strain and deleted Gfr?1 from the majority of UB tip cells post UB induction in vivo and in explant kidney cultures. We report that Gfr?1 excision from the epithelia compartment after UB induction caused a modest reduction in branching morphogenesis. The loss of Gfr?1 from UB-tip cells resulted in reduced cell proliferation and decreased activated ERK (pERK). Further, cells without Gfr?1 expression are able to populate the branching UB tips. These findings delineate previously unclear biological roles of Gfr?1 in the urinary tract and demonstrate its cell-type and stage-specific requirements in kidney development.
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Insulin delivery through nasal route using thiolated microspheres.
Drug Deliv
PUBLISHED: 03-16-2013
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The aim of the present study was to investigate the potential of developed thiolated microspheres for insulin delivery through nasal route. In the present study, cysteine was immobilized on carbopol using EDAC. A total of 269.93?µmol free thiol groups per gram polymer were determined. The prepared nonthiolated and thiolated microspheres were studied for particle shape, size, drug content, swellability, mucoadhesion and in vitro insulin release. The thiolated microspheres exhibited higher mucoadhesion due to formation of covalent bonds via disulfide bridges with the mucus gel layer. Drug permeation through goat nasal mucosa of nonthiolated and thiolated microspheres were found as 52.62?±?2.4% and 78.85?±?3.1% in 6?h, respectively. Thiolated microspheres bearing insulin showed better reduction in blood glucose level (BGL) in comparison to nonthiolated microspheres as 31.23?±?2.12% and 75.25?±?0.93% blood glucose of initial BGL were observed at 6?h after nasal delivery of thiolated and nonthiolated microspheres in streptozotocin-induced diabetic rabbits.
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A Genome-Wide Association Study Reveals ARL15, a Novel Non-HLA Susceptibility Gene for Rheumatoid Arthritis in North Indians.
Arthritis Rheum.
PUBLISHED: 03-13-2013
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Genome-wide association studies (GWAS) and their subsequent meta-analyses have changed the landscape of genetics in rheumatoid arthritis (RA) by uncovering several novel genes. Such studies are heavily weighted by samples from Caucasian populations, but they explain only a small proportion of total heritability. Our previous studies in genetically distinct North Indian RA cohorts have demonstrated apparent allelic/genetic heterogeneity between North Indian and Western populations, warranting GWAS in non-European populations. We undertook this study to detect additional disease-associated loci that may be collectively important in the presence or absence of genes with a major effect.
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F-18 FDG-PET/CT in evaluation of patients with fever of unknown origin.
Jpn J Radiol
PUBLISHED: 02-03-2013
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This study was carried out to evaluate the diagnostic utility of FDG-PET/CT in patients with fever of unknown origin (FUO).
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Interaction between DMRT1 function and genetic background modulates signaling and pluripotency to control tumor susceptibility in the fetal germ line.
Dev. Biol.
PUBLISHED: 02-01-2013
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Dmrt1 (doublesex and mab-3 related transcription factor (1) is a regulator of testis development in vertebrates that has been implicated in testicular germ cell tumors of mouse and human. In the fetal mouse testis Dmrt1 regulates germ cell pluripotency in a strain-dependent manner. Loss of Dmrt1 in 129Sv strain mice results in a >90% incidence of testicular teratomas, tumors consisting cells of multiple germ layers; by contrast, these tumors have never been observed in Dmrt1 mutants of C57BL/6J (B6) or mixed genetic backgrounds. To further investigate the interaction between Dmrt1 and genetic background we compared mRNA expression in wild type and Dmrt1 mutant fetal testes of 129Sv and B6 mice at embryonic day 15.5 (E15.5), prior to overt tumorigenesis. Loss of Dmrt1 caused misexpression of overlapping but distinct sets of mRNAs in the two strains. The mRNAs that were selectively affected included some that changed expression only in one strain or the other and some that changed in both strains but to a greater degree in one versus the other. In particular, loss of Dmrt1 in 129Sv testes caused a more severe failure to silence regulators of pluripotency than in B6 testes. A number of genes misregulated in 129Sv mutant testes also are misregulated in human testicular germ cell tumors (TGCTs), suggesting similar etiology between germ cell tumors in mouse and man. Expression profiling showed that DMRT1 also regulates pluripotency genes in the fetal ovary, although Dmrt1 mutant females do not develop teratomas. Pathway analysis indicated disruption of several signaling pathways in Dmrt1 mutant fetal testes, including Nodal, Notch, and GDNF. We used a Nanos3-cre knock-in allele to perform conditional gene targeting, testing the GDNF coreceptors Gfra1 and Ret for effects on teratoma susceptibility. Conditional deletion of Gfra1 but not Ret in fetal germ cells of animals outcrossed to 129Sv caused a modest but significant elevation in tumor incidence. Despite some variability in genetic background in these crosses, this result is consistent with previous genetic mapping of teratoma susceptibility loci to the region containing Gfra1. Using Nanos3-cre we also uncovered a strong genetic interaction between Dmrt1 and Nanos3, suggesting parallel functions for these two genes in fetal germ cells. Finally, we used chromatin immunoprecipitation (ChIP-seq) analysis to identify a number of potentially direct DMRT1 targets. This analysis suggested that DMRT1 controls pluripotency via transcriptional repression of Esrrb, Nr5a2/Lrh1, and Sox2. Given the strong evidence for involvement of DMRT1 in human TGCT, the downstream genes and pathways identified in this study provide potentially useful candidates for roles in the human disease.
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Dominant frequencies of resting human brain activity as measured by the electrocorticogram.
Neuroimage
PUBLISHED: 01-11-2013
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The brains spontaneous, intrinsic activity is increasingly being shown to reveal brain function, delineate large scale brain networks, and diagnose brain disorders. One of the most studied and clinically utilized types of intrinsic brain activity are oscillations in the electrocorticogram (ECoG), a relatively localized measure of cortical synaptic activity. Here we objectively characterize the types of ECoG oscillations commonly observed over particular cortical areas when an individual is awake and immobile with eyes closed, using a surface-based cortical atlas and cluster analysis. Both methods show that [1] there is generally substantial variability in the dominant frequencies of cortical regions and substantial overlap in dominant frequencies across the areas sampled (primarily lateral central, temporal, and frontal areas), [2] theta (4-8 Hz) is the most dominant type of oscillation in the areas sampled with a mode around 7 Hz, [3] alpha (8-13 Hz) is largely limited to parietal and occipital regions, and [4] beta (13-30 Hz) is prominent peri-Rolandically, over the middle frontal gyrus, and the pars opercularis. In addition, the cluster analysis revealed seven types of ECoG spectral power densities (SPDs). Six of these have peaks at 3, 5, 7 (narrow), 7 (broad), 10, and 17 Hz, while the remaining cluster is broadly distributed with less pronounced peaks at 8, 19, and 42 Hz. These categories largely corroborate conventional sub-gamma frequency band distinctions (delta, theta, alpha, and beta) and suggest multiple sub-types of theta. Finally, we note that gamma/high gamma activity (30+ Hz) was at times prominently observed, but was too infrequent and variable across individuals to be reliably characterized. These results should help identify abnormal patterns of ECoG oscillations, inform the interpretation of EEG/MEG intrinsic activity, and provide insight into the functions of these different oscillations and the networks that produce them. Specifically, our results support theories of the importance of theta oscillations in general cortical function, suggest that alpha activity is primarily related to sensory processing/attention, and demonstrate that beta networks extend far beyond primary sensorimotor regions.
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Targeted exome sequencing integrated with clinicopathological information reveals novel and rare mutations in atypical, suspected and unknown cases of Alport syndrome or proteinuria.
PLoS ONE
PUBLISHED: 01-01-2013
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We applied customized targeted next-generation exome sequencing (NGS) to determine if mutations in genes associated with renal malformations, Alport syndrome (AS) or nephrotic syndrome are a potential cause of renal abnormalities in patients with equivocal or atypical presentation. We first sequenced 4,041 exons representing 292 kidney disease genes in a Caucasian woman with a history of congenital vesicoureteral reflux (VUR), recurrent urinary tract infections and hydronephrosis who presented with nephrotic range proteinuria at the age of 45. Her biopsy was remarkable for focal segmental glomerulosclerosis (FSGS), a potential complication of longstanding VUR. She had no family history of renal disease. Her proteinuria improved initially, however, several years later she presented with worsening proteinuria and microhematuria. NGS analysis revealed two deleterious COL4A3 mutations, one novel and the other previously reported in AS, and a novel deleterious SALL2 mutation, a gene linked to renal malformations. Pedigree analysis confirmed that COL4A3 mutations were nonallelic and compound heterozygous. The genomic results in conjunction with subsequent abnormal electron microscopy, Collagen IV minor chain immunohistochemistry and progressive sensorineural hearing loss confirmed AS. We then modified our NGS approach to enable more efficient discovery of variants associated with AS or a subset of FSGS by multiplexing targeted exome sequencing of 19 genes associated with AS or FSGS in 14 patients. Using this approach, we found novel or known COL4A3 or COL4A5 mutations in a subset of patients with clinically diagnosed or suspected AS, APOL1 variants associated with FSGS in African Americans and novel mutations in genes associated with nephrotic syndrome. These studies demonstrate the successful application of targeted capture-based exome sequencing to simultaneously evaluate genetic variations in many genes in patients with complex renal phenotypes and provide insights into etiology of conditions with equivocal clinical and pathologic presentations.
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Vaccination with recombinant Mycobacterium tuberculosis PknD attenuates bacterial dissemination to the brain in guinea pigs.
PLoS ONE
PUBLISHED: 01-01-2013
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We have previously identified Mycobacterium tuberculosis PknD to be an important virulence factor required for the pathogenesis of central nervous system (CNS) tuberculosis (TB). Specifically, PknD mediates bacillary invasion of the blood-brain barrier, which can be neutralized by specific antisera, suggesting its potential role as a therapeutic target against TB meningitis.
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Mouse model of necrotic tuberculosis granulomas develops hypoxic lesions.
J. Infect. Dis.
PUBLISHED: 12-23-2011
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Preclinical evaluation of tuberculosis drugs is generally limited to mice. However, necrosis and hypoxia, key features of human tuberculosis lesions, are lacking in conventional mouse strains.
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Development of surface-functionalised nanoparticles for FGF2 receptor-based solid tumour targeting.
J Microencapsul
PUBLISHED: 11-30-2011
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The surface-functionalised gelatin nanoparticles (GNPs) containing cisplatin were developed and characterised for breast cancer targeting using fibroblast growth factor-2 (FGF2) receptors which are overexpressed on breast cancer cells. The GNPs were prepared using two-step desolvation method and then the surface of GNPs was functionalised with activated heparin. They were characterised for surface morphology, particle size and size distribution, surface charge, entrapment efficiency and in vitro drug release. The results revealed that the mean diameter of GNPs was 173?±?2.2?nm with smooth surface, which was increased to 189?±?3.4?nm after coupling with heparin (H-GNPs). The targeting effect of H-GNPs and GNPs was investigated by in vitro cell uptake study on human breast cancer MDA-MB-231 cell line, which exhibited greater uptake of H-GNPs as compared to GNPs. Therefore, it is suggested that H-GNPs can be used as an effective carrier for solid tumour targeting.
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A pictorial essay: Radiology of lines and tubes in the intensive care unit.
Indian J Radiol Imaging
PUBLISHED: 10-21-2011
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A variety of devices are used in the intensive care unit for long durations. Each one of them is a double-edged sword: intended to save life, but life-threatening if in the wrong place. Hence, it is important to periodically check that these devices are correctly placed so as to prevent complications. The portable chest radiograph is of tremendous value in this context.
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Diagnostic difficulties of pure intrasinusoidal bone marrow infiltration of non-Hodgkins lymphoma: a report of eight cases from India.
Jpn. J. Clin. Oncol.
PUBLISHED: 09-22-2011
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Bone marrow involvement in non-Hodgkins lymphoma is prognostically important for appropriate management. Intrasinusoidal pattern of bone marrow infiltration is poorly identified on trephine biopsies. We analyzed the clinical, hematological and histopathological spectrum of eight cases of non-Hodgkins lymphoma showing pure intrasinusoidal bone marrow infiltration. Fever, cytopenias and blasts in circulation were the indications for bone marrow aspiration and trephine biopsies. Flow cytometry on bone marrow and immunohistochemistry on trephine sections were done. There were five cases of T-cell hepatosplenic non-Hodgkins lymphoma (three ?? T-cell lymphoma) and three B-cell non-Hodgkins lymphoma (two intravascular large B-cell lymphoma and one splenic marginal zone lymphoma). Except the cases with intravascular large B-cell lymphoma, all showed variable splenomegaly without lymphadenopathy. Immunohistochemistry highlighted intrasinusoidal infiltration, which was difficult to discern on hematoxylin and eosin. This brief analysis highlights that pure intrasinusoidal infiltration of extranodal non-Hodgkins lymphoma requires a high degree of diagnostic suspicion and can be seen in various lymphomas.
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The efficacy and safety of amoxicillin-clavulanic acid 1000/125mg twice daily extended release (XR) tablet for the treatment of bacterial community-acquired pneumonia in adults.
J Indian Med Assoc
PUBLISHED: 09-06-2011
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This study was designed to demonstrate the efficacy and safety of pharmacokinetically enhanced amoxicillin/clavulanic acid 2000 mg/125 mg extended release formulation (ER), than conventional formulations against community-acquired respiratory tract pathogens, particularly Streptococcus pneumoniae, with reduced susceptibility to amoxicillin. This is an open labelled, multicentric, prospective, interventional study carried out across India from June 2008 to March 2009. The study included adult patients (>18 years), weighing between 40 to 60 kg with radiologically confirmed community-acquired pneumonia (CAP). Primary efficacy parameters were clinical response (fever, cough severity, sputum characteristics and improvement in dyspnoea grades) and laboratory parameters. Secondary efficacy parameters were radiological and bacteriological findings at the end of therapy. A total, 727 clinically and radiologically confirmed community-acquired pneumonia patients were enrolled in this study. Eighteen patients were lost to follow-up during study and 709 completed the study as per the study protocol. There was a significant improvement in clinical as well as laboratory parameters at the end of therapy. There was a significant improvement in fever, cough severity, sputum characteristic and dyspnoea grades from 101.88 +/- 1.55, 2.18 +/- 0.76, 1.75 +/- 0.77 and 1.91 +/- 1.23 to 98.14 +/- 0.87 (p < 0.0001), 0.24 +/- 0.45 (p < 0.0001), 0.14 +/- 0.39 (p < 0.0001) and 0.20 +/- 0.47 (p < 0.0001) respectively. Laboratory parameters such as total WBC count and neutrophil percentage decreased significantly from 15317 +/- 662 and 80 +/- 9 to 9067 +/- 558 (p < 0.0001) and 67 +/- 9 (p < 0.0001) respectively at the end of treatment. Bacteriological success and radiological success for amoxicillin-clavulanate 1,000/62.5 mg at the end of treatment was 94.33% (150 of 159) and 98.7% (700 of 709) respectively. Mild to moderate diarrhoea was reported in 61/709 patients (8.6%). Amoxicillin-clavulanate 1,000/62.5 mg given twice daily for ten days was shown to be clinically effective and safe in the treatment of community-acquired pneumonia in adult patients. Therapy was well tolerated. [J Indian Med Assoc 2011; 109: 124-7]
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Trichophyton rubrum onychomycosis in an 8-week-old infant.
Indian J Dermatol Venereol Leprol
PUBLISHED: 08-24-2011
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An 8-week-old infant presented with 7 weeks history of nail involvement and discoloration. Lesions started over the middle fingernail of right hand at 1 week of age, spreading over to other nails within 2 weeks. Only two nails of the feet were spared. On KOH examination, fungal hyphae were seen and culture showed growth of Trichophyton rubrum. The purpose is to report the earliest case of onychomycosis having multiple nail involvement of fingers and toes (18 nails).
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Gastrointestinal toxicity due to bitter bottle gourd (Lagenaria siceraria)--a report of 15 cases.
Indian J Gastroenterol
PUBLISHED: 07-02-2011
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Traditional medicine is widely practiced in tropical countries. Bottle gourd (Lagenaria siceraria) fruit juice is advocated as a part of complementary and alternative medicine. If the bottle gourd juice becomes bitter it is considered toxic. We report 15 patients, who developed toxicity due to drinking bitter bottle gourd juice. Patients presented with abdominal pain, vomiting, hematemesis, diarrhea and hypotension within 15 min to 6-h after ingestion of bottle gourd juice. Endoscopy showed esophagitis, gastric erosions, ulcers and duodenitis. Hypotension was treated with crystalloids and inotropic support. All patients recovered in 1-4 days. Endoscopically the lesions healed in 2 weeks. Bitter bottle gourd can cause gastrointestinal toxicity with hematemesis and hypotension. Supportive management is the treatment and all patients recover within 1 week.
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Mannosylated liposomes bearing Amphotericin B for effective management of visceral Leishmaniasis.
J Liposome Res
PUBLISHED: 05-25-2011
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The cationic and mannosylated liposomes were prepared using the cast film method and compared for their antileishmaniasis activity. The surface of the Amphotericin B (Amp B)-bearing cationic multilamellar liposomes was covalently coupled with p-aminophenyl-?-D-mannoside using glutaraldehyde as a coupling agent, which was confirmed by agglutination of the vesicles with concanavalin A. The prepared liposomes were characterized for shape, size, percent drug entrapment, vesicle count, zeta potential, and in vitro drug release. Vesicle sizes of cationic and mannosylated liposomes were found to be 2.32 ± 0.23 and 2.69 ± 0.13 ?m, respectively. Zeta potential of cationic liposomes was higher (30.38 ± 0.3 mV), as compared to mannosylated liposomes (17.7 ± 0.8 mV). Percentage drug release from cationic and mannose-coupled liposomes was found to be 45.7% ± 3.1 and 41.9% ± 2.8, respectively, after 24 hours. The in vivo antileishmanial activity was performed on Leishmania donovani-infected golden hamster, and results revealed that Amp B solution was reduced by 42.5 ± 1.8% in the parasite load, whereas the placebo cationic liposomes and drug-containing cationic liposomes showed a reduced parasite load (i.e., 28.1 ± 1.5 and 61.2 ± 3.2%, respectively). The mannose-coupled liposomes showed a maximum reduction in parasite load (i.e., 78.8 ± 3.9%). The biodistribution study clearly showed the higher uptake of mannosylated liposomes in the liver and spleen and hence the active targeting to the reticular endothelial system, which, in turn, would provide a direct attack of the drug to the site where the pathogen resides, rendering the other organs free and safe from the toxic manifestations of the drug.
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A rare case of generalized pyogenic granuloma: a case report.
Quintessence Int
PUBLISHED: 04-27-2011
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Gingival enlargement is defined as an overgrowth or increase in size of the gingiva. Enlargement can be of many types depending on etiologic factors like inflammation, drug-induced effects, neoplasm, hormonal imbalance, and systemic involvement (leukemia, etc). Drugs and hormonal imbalance are the most common causes of gingival enlargement. Nonspecific conditioned enlargement, or pyogenic granuloma, is considered an exaggerated conditioned response to minor trauma or chronic irritation. Pyogenic granuloma occurring in the oral cavity is a common phenomenon. However, simultaneously occurring generalized pyogenic granuloma in the oral cavity is a rare entity. Generalized pyogenic granuloma on the back and skin have been reported. This is the first case report of generalized pyogenic granuloma in the oral cavity. A 19-year-old male patient reported with a complaint of difficulty in mastication and generalized swelling of the gingiva that developed within a span of 15 days. Family and systemic history were noncontributory. Based on the clinical findings, histopathology report, and immunohistochemistry result, the patient was diagnosed with generalized pyogenic granuloma. Scaling and root planing were performed as the first phase of therapy followed by external bevel gingivectomy. The patient was followed for 3 months. The patient was advised to visit the clinic for regular maintenance visits for 1 year, as pyogenic granuloma has a tendency to recur.
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Recent studies on aphrodisiac herbs for the management of male sexual dysfunction--a review.
Acta Pol Pharm
PUBLISHED: 04-14-2011
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An aphrodisiac is a type of food or drink that has the effect of making those who eat or drink it more aroused in a sexual way. Aphrodisiacs can be categorized according to their mode of action into three groups: substances that increase libido (i.e., sexual desire, arousal), substances that increase sexual potency (i.e., effectiveness of erection) and substances that increase sexual pleasure. Some well-known aphrodisiacs are Tribulus terrestrins, Withania somnifera, Eurycoma longifolia, Avena sativa, Ginko biloba, and Psoralea coryifolia. Ethnobotanical surveys have indicated a large number of plants as aphrodisiacs. The paper reviews the recent scientific validation on traditionally used herbal plants as aphrodisiac herbs for the management of sexual disorder erectile dysfunction.
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Rib haemangioma: a rare differential for rib tumours.
Indian J Surg
PUBLISHED: 04-09-2011
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Haemangiomas account for approximately 1% of all bone tumours and commonly involve the skull and the vertebrae Dorfman et al. (Human Pathol 2:349-376, 1971). Rare costal originated haemangiomas have been reported as a case report in literature Clements et al. (Am Surgeon 64:1027-1029, 1998), Filosso et al. (J Cardiovasc Surg 36:97-98, 1995). We report a case of 26 years old female presenting with haemangioma of the eighth rib (right). And conclude that haemangiomas should be included in the differential diagnoses of an osteolytic and expansile lesion of the ribs on radiology, especially in asymptomatic or mildly symptomatic patients.
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Strain-dependent CNS dissemination in guinea pigs after Mycobacterium tuberculosis aerosol challenge.
Tuberculosis (Edinb)
PUBLISHED: 04-09-2011
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Clinical reports suggest an association of distinct Mycobacterium tuberculosis strains with CNS disease. We therefore examined CNS dissemination by different laboratory strains (two M. tuberculosis H37Rv, one CDC1551) in a guinea pig aerosol infection model. Although all strains grew exponentially in lungs, with similar bacterial burdens at the time of extrapulmonary dissemination, M. tuberculosis CDC1551 disseminated to the CNS significantly more than the H37Rv strains. No CNS lesions were observed throughout the study, with only a modest cytokine response. These data suggest that M. tuberculosis may have virulence factors that promote CNS dissemination, distinct from those required for pulmonary TB.
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Transferrin-appended PEGylated nanoparticles for temozolomide delivery to brain: in vitro characterisation.
J Microencapsul
PUBLISHED: 04-09-2011
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Polymer-based nanotechnologies are proposed to be an alternative for drug administration, delivery and targeting to those of conventional formulations. The blood brain barrier is frequently a rate-limiting factor in determining permeation of a drug into brain. In this study, the surface-engineered long-circulating PLGA nanoparticles (NPs) were assessed for brain-specific delivery. Long circulating NPs of PLGA- and PEG-synthesised copolymer were prepared by emulsification solvent evaporation method. Further, the surface of PEGylated NPs was modified by anchoring transferrin (Tf) ligand for receptor-mediated targeting to brain. NPs were characterised for shape and size, zeta potential, entrapment efficiency and in vitro drug release. In vitro cytotoxicity studies were performed on human cancer cell lines. Confocal Laser Scanning Microscopy studies show the enhanced uptake of Tf-appended PEGylated NPs and their localisation in the brain tissues. Hence, the specific role of Tf ligand on PEGylated NPs for brain delivery was confirmed.
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Bioconjugation of polymers: a novel platform for targeted drug delivery.
Curr. Pharm. Des.
PUBLISHED: 03-09-2011
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Bioconjugation, a novel technique is usually exploited to improve the biopharmaceutical aspects of a bioactive as well as afford its spatial and temporal distribution. The strategy enlightens newer vistas for delivery of drugs, peptides, enzymes, and oligonucleotides. Site specific delivery may be obtained by tailoring the conjugates as an inactive prodrug and designing polymer drug linkages susceptible to cleavage by specific enzymes or pH. These prodrugs substantially change the mechanisms of cellular entry, pharmacokinetic disposition and ultimately target the drug. The conjugate vehicles are being exploited for targeting pharmacological agents to visceral tissues viz brain, colon etc. These biomaterials are bringing into play, novel drug delivery systems for selectively and specifically ferrying drugs to the desired organ. Noteworthy contributions reported with bioconjugated nanoparticles for biosensing and bioimaging incorporate cell staining, DNA detection, separation and recombination relevance in DNA protection. Only recently, these tailor-made polymers have also gained impetuous for enzyme therapy, gene therapy, insulin therapy, cancer therapy and management of AIDS with the interception of minimal side effects. The present review exhaustively provides an insight to the polymer bioconjugates and their implications for targeted delivery. The article also discusses the therapeutic aspects of these conjugates and that these may serve as fascinating tools for drug delivery.
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Expression profiles of podocytes exposed to high glucose reveal new insights into early diabetic glomerulopathy.
Lab. Invest.
PUBLISHED: 11-22-2010
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Podocyte injury has been suggested to have a pivotal role in the pathogenesis of diabetic glomerulopathy. To glean insights into molecular mechanisms underlying diabetic podocyte injury, we generated temporal global gene transcript profiles of podocytes exposed to high glucose for a time interval of 1 or 2 weeks using microarrays. A number of genes were altered at both 1 and 2 weeks of glucose exposure compared with controls grown under normal glucose. These included extracellular matrix modulators, cell cycle regulators, extracellular transduction signals and membrane transport proteins. Novel genes that were altered at both 1 and 2 weeks of high-glucose exposure included neutrophil gelatinase-associated lipocalin (LCN2 or NGAL, decreased by 3.2-fold at 1 week and by 7.2-fold at 2 weeks), endothelial lipase (EL, increased by 3.6-fold at 1 week and 3.9-fold at 2 week) and UDP-glucuronosyltransferase 8 (UGT8, increased by 3.9-fold at 1 week and 5.0-fold at 2 weeks). To further validate these results, we used real-time PCR from independent podocyte cultures, immunohistochemistry in renal biopsies and immunoblotting on urine specimens from diabetic patients. A more detailed time course revealed changes in LCN2 and EL mRNA levels as early as 6 hours and in UGT8 mRNA level at 12 hours post high-glucose exposure. EL immunohistochemistry on human tissues showed markedly increased expression in glomeruli, and immunoblotting readily detected EL in a subset of urine samples from diabetic nephropathy patients. In addition to previously implicated roles of these genes in ischemic or oxidative stress, our results further support their importance in hyperglycemic podocyte stress and possibly diabetic glomerulopathy pathogenesis and diagnosis in humans.
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Expression regulation and function of heparan sulfate 6-O-endosulfatases in the spermatogonial stem cell niche.
Glycobiology
PUBLISHED: 09-20-2010
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Glial cell line-derived neurotrophic factor (GDNF) is a heparan sulfate (HS)-binding factor. GDNF is produced by somatic Sertoli cells, where it signals to maintain spermatogonial stem cells (SSCs) and reproduction. Here, we investigate the roles of extracellular HS 6-O-endosulfatases (Sulfs), Sulf1 and Sulf2, in the matrix transmission of GDNF from Sertoli cells to SSCs. Although Sulfs are not required for testis formation, Sulf deficiency leads to the accelerated depletion of SSCs, a testis phenotype similar to that of GDNF+/- mice. Mechanistically, we show that Sulfs are expressed in GDNF-producing Sertoli cells. In addition, reduced Sulf activity profoundly worsens haplo-deficient GDNF phenotypes in our genetic studies. These findings establish a critical role of Sulfs in promoting GDNF signaling and support a model in which Sulfs regulate the bioavailability of GDNF by enzymatically remodeling HS 6-O-desulfation to release GDNF from matrix sequestration. Further, Sertoli cell-specific transcriptional factor Wilms tumor 1 (WT1) directly activates the transcription of both Sulf1 and Sulf2 genes. Together, our studies not only identify Sulfs as essential regulators of GDNF signaling in the SSC niche, but also as direct downstream targets of WT1, thus establishing a physiological role of WT1 in Sertoli cells.
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Steroid-coupled liposomes for targeted delivery to tumor.
Ther Deliv
PUBLISHED: 08-01-2010
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The steroidal receptors play a key role in protein synthesis and maintain the homeostasis in normal and diseased state, including tumorigenesis at the target tissues when overactivated. Thus steroidal receptors may act as potential targets for selective delivery of different therapeutic agents as they are overexpressed by a number of endocrinal tumors. The selective delivery of these agents may be a better treatment strategy for endocrinal cancer as it may also result in cytosolic and nuclear delivery of cytotoxic agents. In this review, the targeting potential of steroidal receptors for the drug or bioactive(s) delivery is discussed. The ligands that have been proven to be effective for specific steroidal receptors can be used as vectors for carrying the drug or drug-delivery system to the desired site of drug action in an optimum concentration. This strategy will not only minimize the undesired side effects associated with nonspecific delivery of drug, but will also maximize the drug utilization. Ligand-conjugated liposomes as a carrier of bioactives prevent passive diffusion of the encapsulated drug to normal cells, increase the time of circulation and reduce the undesirable side effects of a drug.
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Evaluation of in vitro antioxidant potential of aqueous extract of Trapa natans L. fruits.
Acta Pol Pharm
PUBLISHED: 07-20-2010
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In the present study, the in vitro antioxidant potential of aqueous extract of Trapa natans L. fruits rind was investigated. The extract was found to contain a large amount of polyphenols and also exhibited an immense reducing ability. The total content of phenolic, flavonoid and tannin compounds was estimated as 63.81 mg of gallic acid equivalents/g of dry material, 21.34 mg of rutin equivalents/g of dry material and 17.11 mg of total tannin equivalent /g of dry material, respectively. IC50 values for different antioxidant model were calculated as 128.86 microg/mL for DPPH radicals, 97.65 microg/mL for O2*-, 148.32 microg/mL for H2O2 and 123.01 microg/mL for NO, respectively. Reducing power and inhibition of *OH radical-induced BSA oxidation were also determined. The data obtained in the present study suggest that the aqueous extract of Trapa natans L. fruit rind have significant antioxidant activity against free radicals.
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Pregnancy and Takayasu arteritis: a single centre experience from North India.
J. Obstet. Gynaecol. Res.
PUBLISHED: 07-06-2010
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Takayasus syndrome is a chronic inflammatory arteriopathy of unknown origin which primarily affects women of reproductive age. We report the course and outcome of 37 pregnancies in 15 women with Takayasu arteritis during the period 1999-2008.
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Chondroitin sulfate functionalized liposomes for solid tumor targeting.
J Drug Target
PUBLISHED: 06-14-2010
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The present investigation was aimed to develop and explore the use of chondroitin sulfate-coupled liposomes (CS-LP) for solid tumor targeting. The liposomes were prepared by cast film method and coupled with chondroitin sulfate. The coupling was confirmed by infrared spectroscopy. They were further characterized for various parameters such as vesicle shape and surface morphology, size and size distribution, zeta potential, entrapment efficiency, and in vitro release pattern. The vesicle size of the uncoupled liposome (256?nm) was found to be less than that of CS-LP (310?nm). In vitro drug release exhibited a release of 44.2% from uncoupled liposomal formulation, compared to 38.3% as observed in coupled formulation at the end of 24?hr. The uptake of the CS-LP and uncoupled liposomes by MDA-MB-231 breast cancer cell lines was visualized using fluorescence microscopy that revealed the dependence of liposomes recognition and higher uptake on the coupling of chondroitin sulfate. Coupling of the liposomes significantly enhanced the tumor uptake of drug, which is reflected in the recovery of a higher percentage of the dose from tumor following administration of CS-LP in comparison to uncoupled liposomes or free drug, suggesting that they can be used as vectors for solid tumor targeting.
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Development and testing of solid dose formulations containing polysialic acid insulin conjugate: next generation of long-acting insulin.
J Diabetes Sci Technol
PUBLISHED: 06-02-2010
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The need for lifelong, daily insulin injections can have a dramatic effect on patient compliance, can be painful, and runs the risk of local infections. Furthermore, needle-stick injuries are common, and the issue of needle disposal is troublesome. Injecting a long-acting insulin analog with needle-free administration would be a significant improvement for diabetic subjects, but is not currently feasible. To achieve a constant, reliable delivery of a novel, long-acting insulin analog, Lipoxens SuliXen (polysialylated insulin) in a solid dosage form capable of being delivered without a needle has been developed. The aim of this study was to evaluate the feasibility of Lipoxens SuliXen delivery with the Glide solid dose injector, Glide SDI.
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