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Find video protocols related to scientific articles indexed in Pubmed.
The impact of routine predischarge pulse oximetry screening in a regional neonatal unit.
Arch. Dis. Child. Fetal Neonatal Ed.
PUBLISHED: 03-21-2014
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(i) To evaluate the impact of routine early pulse oximetry screening on the rate of unexpected neonatal unit (NNU) admissions and the need for echocardiography. (ii) To review the outcomes of babies admitted as a result of a positive pulse oximetry screening test.
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Obstetrical catastrophe averted: successful outcome of an abdominal pregnancy.
Am J Emerg Med
PUBLISHED: 03-19-2014
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Abdominal pregnancy is defined as an implantation in peritoneal cavity, exclusive of tubal, ovarian, or intraligmentary pregnancy.These pregnancies are rarely encountered and can go undiagnosed until advanced period of gestation [1]. Frequency of abdominal pregnancy has been directly related to the frequency of ectopic gestation as constituting 2% of ectopics and nearly 0.01% of all pregnancies [2-4]. These pregnancies are seen more commonly in developing countries and poses special challenges to the clinician. Advanced abdominal pregnancy is life-threatening condition and carries high risk of hemorrhage, disseminated intravascular coagulation, bowel injury, and fistulae [5]. The perinatal outcome is mainly influenced by the availability of blood supply and site of implantation [6]. Most of the fetus die in utero because of compromised environment, and those who survive face problems due to congenital malformations [3,7]. Patients of abdominal pregnancy can have variable clinical presentation, and physical examination may be inconclusive for making diagnosis [7,8]. Clinical features like irregular bleeding per vaginum, abdominal pain, dyspepsia, altered bowel habits, malpresentation, and extremely anteriorly placed cervix should raise the suspicion [2,3,8,9]. Diagnostic challenge with oxytocin stimulation, abdominal x-ray, hysterosalpingography, and ultrasonography has been used as tools to assist in diagnosis [10,11]. Magnetic resonance imaging is found to complement sonography in making accurate diagnosis and can be useful to demonstrate the relationship between fetus, the cervix, and the myometrium [12]. We hereby report a successful operative delivery of a live baby after a term extrauterine abdominal pregnancy in a multigravida in whom the diagnosis was made after laparotomy.
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Relationships of flour solvent retention capacity, secondary structure and rheological properties with the cookie making characteristics of wheat cultivars.
Food Chem
PUBLISHED: 01-25-2014
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The relationships of grain, flour solvent retention capacity (SRC) and dough rheological properties with the cookie making properties of wheat cultivars were evaluated. Cultivars with higher proportion of intermolecular-?-sheets+antiparallel ? sheets and lower ?-helix had greater gluten strength. The grain weight and diameter positively correlated with the proportion of fine particles and the cookie spread factor (SF) and negatively to the grain hardness (GH) and Na2CO3 SRC. The SF was higher in the flour with a higher amount of fine particle and with a lower Na2CO3 SRC and dough stability (DS). The breaking strength (BS) of cookies was positively correlated to lactic acid (LA) SRC, DS, peak time, sedimentation value (SV), G' and G?. Na2CO3 SRC and GH were strongly correlated. The gluten performance index showed a strong positive correlation with SV, DS, G' and G?. The water absorption had a significant positive correlation with sucrose SRC and LASRC. Cultivars with higher GH produced higher amount of coarse particles in flours that had higher Na2CO3 SRC and lower cookie SF.
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The microtubule-associated protein DCAMKL1 regulates osteoblast function via repression of Runx2.
J. Exp. Med.
PUBLISHED: 08-05-2013
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Osteoblasts are responsible for the formation and mineralization of the skeleton. To identify novel regulators of osteoblast differentiation, we conducted an unbiased forward genetic screen using a lentiviral-based shRNA library. This functional genomics analysis led to the identification of the microtubule-associated protein DCAMKL1 (Doublecortin-like and CAM kinase-like 1) as a novel regulator of osteogenesis. Mice with a targeted disruption of Dcamkl1 displayed elevated bone mass secondary to increased bone formation by osteoblasts. Molecular experiments demonstrated that DCAMKL1 represses osteoblast activation by antagonizing Runx2, the master transcription factor in osteoblasts. Key elements of the cleidocranial dysplasia phenotype observed in Runx2(+/-) mice are reversed by the introduction of a Dcamkl1-null allele. Our results establish a genetic linkage between these two proteins in vivo and demonstrate that DCAMKL1 is a physiologically relevant regulator of anabolic bone formation.
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Peripheral blood sCD3(-) CD4(+) T cells: a useful diagnostic tool in angioimmunoblastic T cell lymphoma.
Hematol Oncol
PUBLISHED: 04-18-2013
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Angioimmunoblastic T cell lymphoma (AITL) belongs to the subgroup of mature T cell lymphomas according to the World Health Organization and is one of the common T cell lymphomas in Western countries. Particularly in cases in which histological confirmation cannot be easily achieved, immunophenotyping of peripheral blood can give important information for the differential diagnosis of AITL. sCD3(-) CD4(+) T cells are a typical feature of AILT in flow cytometry of peripheral blood. In this retrospective study, the diagnostic value of flow cytometry for the diagnosis AITL was assessed by comparing the frequency of sCD3(-) CD4(+) T cells in leukemic AITL patients and in patients with other leukemic CD4(+) T cell lymphomas. Immunophenotyping of peripheral blood by flow cytometry was performed in a lymphocyte gate using fluorochrome-labelled antibodies against CD3, CD2, CD4, CD5, CD7, CD8, CD10, CD14, CD16, CD19, CD56, CD57 and T cell receptor. In 17/17 leukemic AITL patients, a small but distinct population of sCD3(-) CD4(+) T cells was detected (mean percentage of sCD3(-) CD4(+) T cells in the lymphocyte gate: 11.9?±?15.4%, range 0.1-51.8%). In contrast, sCD3(-) CD4(+) T cells were found in only 1/40 patients with other leukemic CD4(+) T cell lymphomas (one patient with mycosis fungoides). sCD3(-) CD4(+) T cells have a high positive predictive value (94%) for the diagnosis AITL. Flow cytometry is particularly useful in the differential diagnosis of AITL, even if the aberrant T cell population has a very low frequency. Further biological characterization of this subfraction of lymphoma cells is warranted. Copyright © 2013 John Wiley & Sons, Ltd.
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Transcription factor NRF2 regulates miR-1 and miR-206 to drive tumorigenesis.
J. Clin. Invest.
PUBLISHED: 04-04-2013
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The mechanisms by which deregulated nuclear factor erythroid-2-related factor 2 (NRF2) and kelch-like ECH-associated protein 1 (KEAP1) signaling promote cellular proliferation and tumorigenesis are poorly understood. Using an integrated genomics and ¹³C-based targeted tracer fate association (TTFA) study, we found that NRF2 regulates miR-1 and miR-206 to direct carbon flux toward the pentose phosphate pathway (PPP) and the tricarboxylic acid (TCA) cycle, reprogramming glucose metabolism. Sustained activation of NRF2 signaling in cancer cells attenuated miR-1 and miR-206 expression, leading to enhanced expression of PPP genes. Conversely, overexpression of miR-1 and miR-206 decreased the expression of metabolic genes and dramatically impaired NADPH production, ribose synthesis, and in vivo tumor growth in mice. Loss of NRF2 decreased the expression of the redox-sensitive histone deacetylase, HDAC4, resulting in increased expression of miR-1 and miR-206, and not only inhibiting PPP expression and activity but functioning as a regulatory feedback loop that repressed HDAC4 expression. In primary tumor samples, the expression of miR-1 and miR-206 was inversely correlated with PPP gene expression, and increased expression of NRF2-dependent genes was associated with poor prognosis. Our results demonstrate that microRNA-dependent (miRNA-dependent) regulation of the PPP via NRF2 and HDAC4 represents a novel link between miRNA regulation, glucose metabolism, and ROS homeostasis in cancer cells.
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Computed-tomography-guided high-dose-rate brachytherapy (CT-HDRBT) ablation of metastases adjacent to the liver hilum.
Eur J Radiol
PUBLISHED: 03-30-2013
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To evaluate technical feasibility and clinical outcome of computed tomography-guided high-dose-rate-brachytherapy (CT-HDRBT) ablation of metastases adjacent to the liver hilum.
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Histone deacetylase 6-mediated selective autophagy regulates COPD-associated cilia dysfunction.
J. Clin. Invest.
PUBLISHED: 03-01-2013
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Chronic obstructive pulmonary disease (COPD) involves aberrant airway inflammatory responses to cigarette smoke (CS) that are associated with epithelial cell dysfunction, cilia shortening, and mucociliary clearance disruption. Exposure to CS reduced cilia length and induced autophagy in vivo and in differentiated mouse tracheal epithelial cells (MTECs). Autophagy-impaired (Becn1+/- or Map1lc3B-/-) mice and MTECs resisted CS-induced cilia shortening. Furthermore, CS increased the autophagic turnover of ciliary proteins, indicating that autophagy may regulate cilia homeostasis. We identified cytosolic deacetylase HDAC6 as a critical regulator of autophagy-mediated cilia shortening during CS exposure. Mice bearing an X chromosome deletion of Hdac6 (Hdac6-/Y) and MTECs from these mice had reduced autophagy and were protected from CS-induced cilia shortening. Autophagy-impaired Becn1-/-, Map1lc3B-/-, and Hdac6-/Y mice or mice injected with an HDAC6 inhibitor were protected from CS-induced mucociliary clearance (MCC) disruption. MCC was preserved in mice given the chemical chaperone 4-phenylbutyric acid, but was disrupted in mice lacking the transcription factor NRF2, suggesting that oxidative stress and altered proteostasis contribute to the disruption of MCC. Analysis of human COPD specimens revealed epigenetic deregulation of HDAC6 by hypomethylation and increased protein expression in the airways. We conclude that an autophagy-dependent pathway regulates cilia length during CS exposure and has potential as a therapeutic target for COPD.
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Discordant results obtained with Francisella tularensis during in vitro and in vivo immunological studies are attributable to compromised bacterial structural integrity.
PLoS ONE
PUBLISHED: 02-05-2013
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Francisella tularensis (Ft) is a highly infectious intracellular pathogen and the causative agent of tularemia. Because Ft can be dispersed via small droplet-aerosols and has a very low infectious dose it is characterized as a category A Select Agent of biological warfare. Respiratory infection with the attenuated Live Vaccine Strain (LVS) and the highly virulent SchuS4 strain of Ft engenders intense peribronchiolar and perivascular inflammation, but fails to elicit select pro-inflammatory mediators (e.g., TNF, IL-1?, IL-6, IL-12, and IFN-?) within the first ~72 h. This in vivo finding is discordant with the principally TH1-oriented response to Ft frequently observed in cell-based studies wherein the aforementioned cytokines are produced. An often overlooked confounding factor in the interpretation of experimental results is the influence of environmental cues on the bacteriums capacity to elicit certain host responses. Herein, we reveal that adaptation of Ft to its mammalian host imparts an inability to elicit select pro-inflammatory mediators throughout the course of infection. Furthermore, in vitro findings that non-host adapted Ft elicits such a response from host cells reflect aberrant recognition of the DNA of structurally-compromised bacteria by AIM2-dependent and -independent host cell cytosolic DNA sensors. Growth of Ft in Muller-Hinton Broth or on Muller-Hinton-based chocolate agar plates or genetic mutation of Ft was found to compromise the structural integrity of the bacterium thus rendering it capable of aberrantly eliciting pro-inflammatory mediators (e.g., TNF, IL-1?, IL-6, IL-12, and IFN-?). Our studies highlight the profound impact of different growth conditions on host cell response to infection and demonstrate that not all in vitro-derived findings may be relevant to tularemia pathogenesis in the mammalian host. Rational development of a vaccine and immunotherapeutics can only proceed from a foundation of knowledge based upon in vitro findings that recapitulate those observed during natural infection.
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The redox-sensitive transcription factor Nrf2 regulates murine hematopoietic stem cell survival independently of ROS levels.
Blood
PUBLISHED: 10-28-2011
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Several studies have found that high levels of reactive oxidative species (ROS) are associated with stem cell dysfunction. In the present study, we investigated the role of nuclear factor erythroid-2-related factor 2 (Nrf2), a master regulator of the antioxidant response, and found that it is required for hematopoietic stem progenitor cell (HSPC) survival and myeloid development. Although the loss of Nrf2 leads to increased ROS in most tissues, basal ROS levels in Nrf2-deficient (Nrf2(-/-)) BM were not elevated compared with wild-type. Nrf2(-/-) HSPCs, however, had increased rates of spontaneous apoptosis and showed decreased survival when exposed to oxidative stress. Nrf2(-/-) BM demonstrated defective stem cell function, as evidenced by reduced chimerism after transplantation that was not rescued by treatment with the antioxidant N-acetyl cysteine. Gene-expression profiling revealed that the levels of prosurvival cytokines were reduced in Nrf2(-/-) HSPCs. Treatment with the cytokine G-CSF improved HSPC survival after exposure to oxidative stress and rescued the transplantation defect in Nrf2(-/-) cells despite increases in ROS induced by cytokine signaling. These findings demonstrate a critical role for Nrf2 in hematopoiesis and stem cell survival that is independent of ROS levels.
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Enhancing Nrf2 pathway by disruption of Keap1 in myeloid leukocytes protects against sepsis.
Am. J. Respir. Crit. Care Med.
PUBLISHED: 07-28-2011
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Sepsis syndrome is characterized by inappropriate amplified systemic inflammatory response and bacteremia that promote multiorgan failure and mortality. Nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) regulates a pleiotropic cytoprotective defense program including antioxidants and protects against several inflammatory disorders by inhibiting oxidative tissue injuries. However, the role of enhanced Nrf2 activity in modulating innate immune responses to microbial infection and pathogenesis of sepsis is unclear.
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Lymphocyte populations in joint tissues from dogs with inflammatory stifle arthritis and associated degenerative cranial cruciate ligament rupture.
Vet Surg
PUBLISHED: 07-19-2011
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To evaluate lymphocyte populations in stifle synovium and synovial fluid of dogs with degenerative cranial cruciate ligament rupture (CCLR).
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Development of tolerogenic dendritic cells and regulatory T cells favors exponential bacterial growth and survival during early respiratory tularemia.
J. Leukoc. Biol.
PUBLISHED: 07-01-2011
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Tularemia is a vector-borne zoonosis caused by Ft, a Gram-negative, facultative intracellular bacterium. Ft exists in two clinically relevant forms, the European biovar B (holarctica), which produces acute, although mild, self-limiting infections, and the more virulent United States biovar A (tularensis), which is often associated with pneumonic tularemia and more severe disease. In a mouse model of tularemia, respiratory infection with the virulence-attenuated Type B (LVS) or highly virulent Type A (SchuS4) strain engenders peribronchiolar and perivascular inflammation. Paradoxically, despite an intense neutrophilic infiltrate and high bacterial burden, T(h)1-type proinflammatory cytokines (e.g., TNF, IL-1?, IL-6, and IL-12) are absent within the first ?72 h of pulmonary infection. It has been suggested that the bacterium has the capacity to actively suppress or block NF-?B signaling, thus causing an initial delay in up-regulation of inflammatory mediators. However, our previously published findings and those presented herein contradict this paradigm and instead, strongly support an alternative hypothesis. Rather than blocking NF-?B, Ft actually triggers TLR2-dependent NF-?B signaling, resulting in the development and activation of tDCs and the release of anti-inflammatory cytokines (e.g., IL-10 and TGF-?). In turn, these cytokines stimulate development and proliferation of T(regs) that may restrain T(h)1-type proinflammatory cytokine release early during tularemic infection. The highly regulated and overall anti-inflammatory milieu established in the lung is permissive for unfettered growth and survival of Ft. The capacity of Ft to evoke such a response represents an important immune-evasive strategy.
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Administration of BMP2/7 in utero partially reverses Rubinstein-Taybi syndrome-like skeletal defects induced by Pdk1 or Cbp mutations in mice.
J. Clin. Invest.
PUBLISHED: 06-13-2011
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Mutations in the coactivator CREB-binding protein (CBP) are a major cause of the human skeletal dysplasia Rubinstein-Taybi syndrome (RTS); however, the mechanism by which these mutations affect skeletal mineralization and patterning is unknown. Here, we report the identification of 3-phosphoinositide-dependent kinase 1 (PDK1) as a key regulator of CBP activity and demonstrate that its functions map to both osteoprogenitor cells and mature osteoblasts. In osteoblasts, PDK1 activated the CREB/CBP complex, which in turn controlled runt-related transcription factor 2 (RUNX2) activation and expression of bone morphogenetic protein 2 (BMP2). These pathways also operated in vivo, as evidenced by recapitulation of RTS spectrum phenotypes with osteoblast-specific Pdk1 deletion in mice (Pdk1osx mice) and by the genetic interactions observed in mice heterozygous for both osteoblast-specific Pdk1 deletion and either Runx2 or Creb deletion. Finally, treatment of Pdk1osx and Cbp+/- embryos with BMPs in utero partially reversed their skeletal anomalies at birth. These findings illustrate the in vivo function of the PDK1-AKT-CREB/CBP pathway in bone formation and provide proof of principle for in utero growth factor supplementation as a potential therapy for skeletal dysplasias.
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Degradation of lindane contaminated soil using zero-valent iron nanoparticles.
J Biomed Nanotechnol
PUBLISHED: 04-14-2011
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Lindane, has been classified by the United States Environment Protection Agency as a potent carcinogen and teratogen. Zero-valent iron nanoparticles (nZVI) have been shown to effectively transform chlorinated hydrocarbons, organochlorine pesticides. An attempt has been made to explore the potential of nZVI for the remediation of Lindane contaminated soil. nZVI was synthesized by reducing FeCl3 with NaBH4. Lindane (10 microg/g) completely disappeared from spiked soil within 24 hours at nZVI concentration of 1.6 g/L, indicating its possible use in environmental cleanup. Reductive dehalogenation is the predominant mechanism for the removal of Lindane from spiked soil by nZVI. Dechlorination was further confirmed by the chloride ion release.
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Host-adaptation of Francisella tularensis alters the bacteriums surface-carbohydrates to hinder effectors of innate and adaptive immunity.
PLoS ONE
PUBLISHED: 03-14-2011
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The gram-negative bacterium Francisella tularensis survives in arthropods, fresh water amoeba, and mammals with both intracellular and extracellular phases and could reasonably be expected to express distinct phenotypes in these environments. The presence of a capsule on this bacterium has been controversial with some groups finding such a structure while other groups report that no capsule could be identified. Previously we reported in vitro culture conditions for this bacterium which, in contrast to typical methods, yielded a bacterial phenotype that mimics that of the bacteriums mammalian, extracellular phase.
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CD14 signaling reciprocally controls collagen deposition and turnover to regulate the development of lyme arthritis.
Am. J. Pathol.
PUBLISHED: 02-02-2011
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CD14 is a glycosylphosphatidylinositol-anchored protein expressed primarily on myeloid cells (eg, neutrophils, macrophages, and dendritic cells). CD14(-/-) mice infected with Borrelia burgdorferi, the causative agent of Lyme disease, produce more proinflammatory cytokines and present with greater disease and bacterial burden in infected tissues. Recently, we uncovered a novel mechanism whereby CD14(-/-) macrophages mount a hyperinflammatory response, resulting from their inability to be tolerized by B. burgdorferi. Paradoxically, CD14 deficiency is associated with greater bacterial burden despite the presence of highly activated neutrophils and macrophages and elevated levels of cytokines with potent antimicrobial activities. Killing and clearance of Borrelia, especially in the joints, depend on the recruitment of neutrophils. Neutrophils can migrate in response to chemotactic gradients established through the action of gelatinases (eg, matrix metalloproteinase 9), which degrade collagen components of the extracellular matrix to generate tripeptide fragments of proline-glycine-proline. Using a mouse model of Lyme arthritis, we demonstrate that CD14 deficiency leads to decreased activation of matrix metalloproteinase 9, reduced degradation of collagen, and diminished recruitment of neutrophils. This reduction in neutrophil numbers is associated with greater numbers of Borrelia in infected tissues. Variation in the efficiency of neutrophil-mediated clearance of B. burgdorferi may underlie differences in the severity of Lyme arthritis observed in the patient population and suggests avenues for development of adjunctive therapy designed to augment host immunity.
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Antioxidant components of naturally-occurring oils exhibit marked anti-inflammatory activity in epithelial cells of the human upper respiratory system.
Respir. Res.
PUBLISHED: 01-28-2011
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The upper respiratory tract functions to protect lower respiratory structures from chemical and biological agents in inspired air. Cellular oxidative stress leading to acute and chronic inflammation contributes to the resultant pathology in many of these exposures and is typical of allergic disease, chronic sinusitis, pollutant exposure, and bacterial and viral infections. Little is known about the effective means by which topical treatment of the nose can strengthen its antioxidant and anti-inflammatory defenses. The present study was undertaken to determine if naturally-occurring plant oils with reported antioxidant activity can provide mechanisms through which upper respiratory protection might occur.
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KEAP1 gene mutations and NRF2 activation are common in pulmonary papillary adenocarcinoma.
J. Hum. Genet.
PUBLISHED: 01-20-2011
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Distinctive histological variants of lung cancer are increasingly recognized to have specific genetic changes that affect tumor biology and response to therapy. In this study, we evaluated true papillary adenocarcinoma of the lung, proposed as a distinct diagnostic category with relatively poor response to therapy, to determine whether these tumors also have specific molecular alterations that would affect sensitivity to chemotherapy. Specifically, we measured protein levels of P53, excision repair cross-complementation 1 (ERCC1) and ribonucleotide reductase M1 (RRM1) by immunohistochemistry and evaluated the Kelch-like erythroid cell-derived protein with cap-n-collar homology (ECH)-associated protein 1 (KEAP1) gene for mutations, correlating mutations of this gene with total and nuclear expression of the nuclear factor erythroid-2-related factor 2 (NRF2). We found high levels of P53 in 23 of the 55 specimens (41.8%), similar to the rate of P53 gene mutations observed in general for pulmonary adenocarcinoma, and levels of ERCC1 and RRM1 also showed distributions similar to those reported generally for non-small lung cell cancer (NSCLC). However, KEAP1 alterations were observed at a significantly higher frequency in papillary adenocarcinoma tumors (60%) than what has been reported previously for NSCLC (3-19%). These mutations of KEAP1 were associated with increased nuclear accumulation of NRF2 in tumors, as expected for functional alterations. Thus, high rates of KEAP1 mutations and NRF2 overexpression in true papillary adenocarcinoma could be related to poor prognosis and chemotherapy resistance. Furthermore, this distinctive molecular characteristic supports the recognition of true papillary adenocarcinoma as a diagnostic entity.
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Critical pulmonary stenosis: challenges following surgical correction.
World J Pediatr Congenit Heart Surg
PUBLISHED: 01-01-2011
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A 20-day-old girl was diagnosed with critical pulmonary valvular stenosis with patent ductus arteriosus (PDA). She underwent surgical pulmonary valvotomy and infundibular resection. A trial snaring of the PDA resulted in significant systemic desaturation, and the PDA was left undivided. A continuous infusion of prostaglandin was used to keep the PDA open for the next 8 days. The PDA acted as a "natural systemic-to-pulmonary shunt" to provide pulmonary blood flow until right ventricular compliance and function improved. The various causes of persistent desaturation following pulmonary valvotomy are discussed.
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Effect of aluminum (Al3+) on granulation in upflow anaerobic sludge blanket reactor treating low-strength synthetic wastewater.
Water Environ. Res.
PUBLISHED: 09-22-2010
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The effect of aluminum on agglomeration in the sludge bed and chemical oxygen demand (COD) removal efficiency in laboratory-scale upflow anaerobic sludge blanket (UASB) reactors treating low-strength synthetic wastewater (approximately 665 to 738 mg/L of COD) was investigated. Continuous application of aluminum chloride (200 mg/L) caused poor COD removal, less sludge density, and adversely affected agglomeration in the sludge bed. An adverse effect on granulation also was observed when 300 mg/L aluminum chloride was added only during the startup, and the effect continued even after it was discontinued. A lower concentration of aluminum chloride (50 mg/L) added for 30 days after the reactors reached steady-state did not affect the COD removal efficiency, but adversely affected the growth of agglomerates and caused temporary degeneration of existing agglomerates. The adverse effect of aluminum appeared to stem from the precipitation of aluminum hydroxide on the surfaces of agglomerates. The effect of aluminum on agglomeration was shown to be a function of influent strength.
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Regulation of memory CD8 T-cell differentiation by cyclin-dependent kinase inhibitor p27Kip1.
Mol. Cell. Biol.
PUBLISHED: 08-30-2010
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Induction of potent T-cell memory is the goal of vaccinations, but the molecular mechanisms that regulate the formation of memory CD8 T cells are not well understood. Despite the recognition that controls of cellular proliferation and apoptosis govern the number of memory T cells, the cell cycle regulatory mechanisms that control these key cellular processes in CD8 T cells during an immune response are poorly defined. Here, we have identified the cyclin-dependent kinase inhibitor p27(Kip1) as a critical regulator of the CD8 T-cell homeostasis at all phases of the T-cell response to an acute viral infection in mice. By acting as a timer for cell cycle exit, p27(Kip1) curtailed the programmed expansion of interleukin-2-producing memory precursors and markedly limited the magnitude and quality of CD8 T-cell memory. In the absence of p27(Kip1), CD8 T cells showed superior recall responses shortly after vaccination with recombinant Listeria monocytogenes. Additionally, we show that p27(Kip1) constrains proliferative renewal of memory CD8 T cells, especially of the effector memory subset. These findings provide critical insights into the cell cycle regulation of CD8 T-cell homeostasis and suggest that modulation of p27(Kip1) could bolster vaccine-induced T-cell memory and protective immunity.
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Expression of ABCG2 (BCRP) is regulated by Nrf2 in cancer cells that confers side population and chemoresistance phenotype.
Mol. Cancer Ther.
PUBLISHED: 08-03-2010
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ATP-binding cassette, subfamily G, member 2 (ABCG2) is expressed in both normal and cancer cells and plays a crucial role in side population (SP) formation and efflux of xenobiotics and drugs. Nrf2, a redox-sensing transcription factor, on constitutive activation in non-small-cell lung cancer cells upregulates a wide spectrum of genes involved in redox balance, glutathione metabolism, and drug detoxification, which contribute to chemoresistance and tumorigenicity. This study examined the mechanism underlying Nrf2-dependent expression of ABCG2 and its role in the multidrug resistance phenotype. In silico analysis of the 5-promoter flanking region of ABCG2 identified an antioxidant response element (ARE) at -431 to -420 bp. A detailed promoter analysis using luciferase reporter assays showed that ARE at -431 to -420 bp is critical for the Nrf2-mediated expression in lung cancer cells. Electrophoretic mobility shift assays and chromatin immunoprecipitation assays revealed that Nrf2 interacts with the ABCG2 ARE element at -431 to -420 bp in vitro and in vivo. Disruption of Nrf2 expression in lung and prostate cancer cells, by short hairpin RNA, attenuated the expression of ABCG2 transcript and protein, and dramatically reduced the SP fraction in Nrf2-depleted cancer cells. Moreover, depleted levels of ABCG2 in these Nrf2 knockdown cells sensitized them to mitoxantrone and topotecan, two chemotherapy drugs detoxified mainly by ABCG2. As expected, overexpression of Nrf2 cDNA in lung epithelial cells led to an increase in ABCG2 expression and a 2-fold higher SP fraction. Thus, Nrf2-mediated regulation of ABCG2 expression maintains the SP fraction and confers chemoresistance.
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Gain of Nrf2 function in non-small-cell lung cancer cells confers radioresistance.
Antioxid. Redox Signal.
PUBLISHED: 07-13-2010
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Nuclear factor erythroid-2 related factor 2 (Nrf2), a redox-sensitive transcription factor, regulates the expression of antioxidant enzymes and several anti-apoptotic proteins, which confer cytoprotection against oxidative stress and apoptosis. Constitutive activation of Nrf2 in lung cancer cells promotes tumorigenicity and contributes to chemoresistance by upregulation of glutathione, thioredoxin, and the drug efflux pathways involved in detoxification of electrophiles and broad spectrum of drugs. In this study, we show that RNAi-mediated lowering of Nrf2 levels in non-small-cell lung cancer (NSCLC) cell lines (A549 and H460) led to a dramatic increase in endogenous reactive oxygen species (ROS) levels. Similarly, ?-irradiation-induced formation of protein carbonyls were significantly higher in Nrf2-depleted lung cancer cells, suggesting increased lethality of ionizing radiation in the absence of Nrf2. Radiation-induced protein oxidation in Nrf2shRNA cells correlated with reduced survival as measured by clonogenic assay. Radiation-induced cell death was abrogated by pretreatment with antioxidants such as N-acetyl-L-cysteine, glutathione, and vitamin-E, highlighting the importance of antioxidants in conferring protection against radiation injury. Using genetically-modified gain and loss of function models of Nrf2, in mouse embryonic fibroblasts, we establish that constitutive activation of Nrf2 protects against ionizing radiation toxicity and confers radioresistance. Thus, targeting Nrf2 activity in radioresistant tumors could be a promising strategy to circumvent radioresistance.
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Diversity of Frankia strains nodulating Hippophae salicifolia D. Don using FAME profiling as chemotaxonomic markers.
J. Basic Microbiol.
PUBLISHED: 05-18-2010
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Twelve Frankia strains isolated from Hippophae salicifolia D. Don or Alnus glutinosa or Comptonia peregrine, showed the significant variation in fatty acid composition viz. palmitic acid (16:0), oleic acid (18:1), linoleic acid (18:2), linolenic acid (18:3), arachidic acid (20:0) and erucic acid (22:1) suggesting the strain specific variability among the Frankia strains. Presence of Erucic acid (22:1), a major component of the oil obtained from the seeds of Brassica sp., albeit in lesser amount in the few studied frankial strains, is the first report. Cluster analysis on the basis of fatty acid composition suggests the presence of two distinct clusters with similitude coefficient ranging from 0.75 to 1.00. Cluster I with HsIi2 showed great divergence from other 11 frankial strains (Cluster II). The two sub groups were distinguished in cluster II: IIa contained five strains isolated from H. salicifolia and these strains are distantly related to the strains of cluster IIb isolated from different host. There is high degree of similarity among the frankial strains of Cluster IIb which suggests that the frankial strains might be evolved from the same ancestor. FAME profiling might be useful tool in the study of polyphasic approach based taxonomy and phylogenetic relationship.
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Global mapping of binding sites for Nrf2 identifies novel targets in cell survival response through ChIP-Seq profiling and network analysis.
Nucleic Acids Res.
PUBLISHED: 05-11-2010
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The Nrf2 (nuclear factor E2 p45-related factor 2) transcription factor responds to diverse oxidative and electrophilic environmental stresses by circumventing repression by Keap1, translocating to the nucleus, and activating cytoprotective genes. Nrf2 responses provide protection against chemical carcinogenesis, chronic inflammation, neurodegeneration, emphysema, asthma and sepsis in murine models. Nrf2 regulates the expression of a plethora of genes that detoxify oxidants and electrophiles and repair or remove damaged macromolecules, such as through proteasomal processing. However, many direct targets of Nrf2 remain undefined. Here, mouse embryonic fibroblasts (MEF) with either constitutive nuclear accumulation (Keap1(-/-)) or depletion (Nrf2(-/-)) of Nrf2 were utilized to perform chromatin-immunoprecipitation with parallel sequencing (ChIP-Seq) and global transcription profiling. This unique Nrf2 ChIP-Seq dataset is highly enriched for Nrf2-binding motifs. Integrating ChIP-Seq and microarray analyses, we identified 645 basal and 654 inducible direct targets of Nrf2, with 244 genes at the intersection. Modulated pathways in stress response and cell proliferation distinguish the inducible and basal programs. Results were confirmed in an in vivo stress model of cigarette smoke-exposed mice. This study reveals global circuitry of the Nrf2 stress response emphasizing Nrf2 as a central node in cell survival response.
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Loss of Kelch-like ECH-associated protein 1 function in prostate cancer cells causes chemoresistance and radioresistance and promotes tumor growth.
Mol. Cancer Ther.
PUBLISHED: 02-02-2010
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Loss-of-function mutations in the nuclear factor erythroid-2-related factor 2 (Nrf2) inhibitor Kelch-like ECH-associated protein 1 (Keap1) result in increased Nrf2 activity in non-small cell lung cancer and confer therapeutic resistance. We detected point mutations in Keap1 gene, leading to nonconservative amino acid substitutions in prostate cancer cells. We found novel transcriptional and posttranscriptional mechanisms of Keap1 inactivation, such as promoter CpG island hypermethylation and aberrant splicing of Keap1, in DU-145 cells. Very low levels of Keap1 mRNA were detected in DU-145 cells, which significantly increased by treatment with DNA methyltransferase inhibitor 5-aza-deoxycytidine. The loss of Keap1 function led to an enhanced activity of Nrf2 and its downstream electrophile/drug detoxification pathway. Inhibition of Nrf2 expression in DU-145 cells by RNA interference attenuated the expression of glutathione, thioredoxin, and the drug efflux pathways involved in counteracting electrophiles, oxidative stress, and detoxification of a broad spectrum of drugs. DU-145 cells constitutively expressing Nrf2 short hairpin RNA had lower levels of total glutathione and higher levels of intracellular reactive oxygen species. Attenuation of Nrf2 function in DU-145 cells enhanced sensitivity to chemotherapeutic drugs and radiation-induced cell death. In addition, inhibition of Nrf2 greatly suppressed in vitro and in vivo tumor growth of DU-145 prostate cancer cells. Thus, targeting the Nrf2 pathway in prostate cancer cells may provide a novel strategy to enhance chemotherapy and radiotherapy responsiveness and ameliorate the growth and tumorigenicity, leading to improved clinical outcomes.
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Nrf2-dependent sulfiredoxin-1 expression protects against cigarette smoke-induced oxidative stress in lungs.
Free Radic. Biol. Med.
PUBLISHED: 09-26-2009
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Oxidative stress results in protein oxidation and is involved in the pathogenesis of lung diseases such as chronic obstructive pulmonary disorder (COPD). Sulfiredoxin-1 (Srx1) catalyzes the reduction of cysteine sulfinic acid to sulfenic acid in oxidized proteins and protects them from inactivation. This study examined the mechanism of transcriptional regulation of Srx1 and its possible protective role during oxidative stress associated with COPD. Nrf2, a transcription factor known to influence susceptibility to pulmonary diseases, upregulates Srx1 expression during oxidative stress caused by cigarette smoke exposure in the lungs of mice. Disruption of Nrf2 signaling by genetic knockout in mice or RNAi in cells downregulated the expression of Srx1. In silico analysis of the 5-promoter-flanking region of Srx1 identified multiple antioxidant-response elements (AREs) that are highly conserved. Reporter and chromatin-immunoprecipitation assays demonstrated that ARE1 at -228 is critical for the Nrf2-mediated response. Attenuation of Srx1 expression with RNAi potentiated the toxicity of hydrogen peroxide (H2O2), whereas overexpression of Srx1 protected against H2O2-mediated cell death in vitro. Immunoblot analysis revealed dramatic decreases in Srx1 expression in lungs from patients with COPD relative to nonemphysematous lungs together with a decline in Nrf2 protein. Thus, Srx1, a key Nrf2-regulated gene, contributes to protection against oxidative injury in the lung.
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Deletion of Keap1 in the lung attenuates acute cigarette smoke-induced oxidative stress and inflammation.
Am. J. Respir. Cell Mol. Biol.
PUBLISHED: 06-11-2009
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Exposure to cigarette smoke (CS) is the primary factor associated with the development of chronic obstructive pulmonary disease (COPD). CS increases the level of oxidants in the lungs, resulting in a depletion of antioxidants, which promotes oxidative stress and the destruction of alveolar tissue. In response to CS, pulmonary epithelial cells counteract increased levels of oxidants by activating Nrf2-dependent pathways to augment the expression of detoxification and antioxidant enzymes, thereby protecting the lung from injury. We hypothesize that increasing the pathways activated by Nrf2 will afford protection against CS-induced lung damage. To this end we have developed a novel mouse model in which the cytosolic inhibitor of Nrf2, Keap1, is genetically deleted in Clara cells, which predominate in the upper airways in mice. Deletion of Keap1 in Clara cells resulted in increased expression of Nrf2-dependent genes, such as Nqo1 and Gclm, as determined by microarray analysis and quantitative PCR. Deletion of Keap1 in airway epithelium decreased Keap1 protein levels and significantly increased the total level of glutathione in the lungs. Increased Nrf2 activation protected Clara cells against oxidative stress ex vivo and attenuated oxidative stress and CS-induced inflammation in vivo. Expression of KEAP1 was also decreased in human epithelial cells through siRNA transfection, which increased the expression of Nrf2-dependent genes and attenuated oxidative stress. In conclusion, activating Nrf2 pathways in tissue-specific Keap1 knockout mice represents an important genetic approach against oxidant-induced lung damage.
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The short-form revised Eysenck personality questionnaire: A Hindi edition (EPQRS-H).
Ind Psychiatry J
PUBLISHED: 01-01-2009
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There is a growing consensus about the validity of human personality traits as important dispositions toward feelings and behaviors (Matthews, Deary, & Whiteman, 2003).
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p27(Kip1) negatively regulates the magnitude and persistence of CD4 T cell memory.
J. Immunol.
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Much is known about the differentiation of naive T cells into distinct lineages of effector cells, but the molecular mechanisms underlying the generation and maintenance of CD4 T cell memory are poorly characterized. Our studies ascribe a novel role for the cell cycle regulator p27(Kip1) as a prominent negative regulator of the establishment and long-term maintenance of Th1 CD4 T cell memory. We demonstrate that p27(Kip1) might restrict the differentiation and survival of memory precursors by increasing the T-bet/Bcl-6 ratio in effector CD4 T cells. By promoting apoptosis and contraction of effector CD4 T cells by mechanisms that are at least in part T cell intrinsic, p27(Kip1) markedly limits the abundance of memory CD4 T cells. Furthermore, we causally link p27(Kip1)-dependent apoptosis to the decay of CD4 T cell memory, possibly by repressing the expression of ?-chain receptors and the downstream effector of the Wnt/?-catenin signaling pathway, Tcf-1. We extend these findings by showing that the antagonistic effects of p27(Kip1) on CD4 T cell memory require its cyclin-dependent kinase-binding domain. Collectively, these findings provide key insights into the mechanisms underlying the governance of peripheral CD4 T cell homeostasis and identify p27(Kip1) as a target to enhance vaccine-induced CD4 T cell memory.
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Prolonged sulforaphane treatment does not enhance tumorigenesis in oncogenic K-ras and xenograft mouse models of lung cancer.
J Carcinog
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Sulforaphane (SFN), an activator of nuclear factor erythroid-2 related factor 2 (Nrf2), is a promising chemopreventive agent which is undergoing clinical trial for several diseases. Studies have indicated that there is gain of Nrf2 function in lung cancer and other solid tumors because of mutations in the inhibitor Kelch-like ECH-associated protein 1 (Keap1). More recently, several oncogenes have been shown to activate Nrf2 signaling as the main prosurvival pathway mediating ROS detoxification, senescence evasion, and neoplastic transformation. Thus, it is important to determine if there is any risk of enhanced lung tumorigenesis associated with prolonged administration of SFN using mouse models of cancer.
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Management of Pseudohypoparathyroidism Type 1a during Pregnancy and Labor: A Case Report.
Case Rep Obstet Gynecol
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Pseudohypoparathyroidism is rare during pregnancy and poses multiple challenges related to its diagnosis and management during pregnancy. We hereby report a case of a young woman who was diagnosed to have type 1a pseudohypoparathyroidism. She was managed by multidisciplinary team and had good maternal and perinatal outcome. Management-related issues are discussed here in detail.
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Naturally occurring hypothermia is more advantageous than fever in severe forms of lipopolysaccharide- and Escherichia coli-induced systemic inflammation.
Am. J. Physiol. Regul. Integr. Comp. Physiol.
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The natural switch from fever to hypothermia observed in the most severe cases of systemic inflammation is a phenomenon that continues to puzzle clinicians and scientists. The present study was the first to evaluate in direct experiments how the development of hypothermia vs. fever during severe forms of systemic inflammation impacts the pathophysiology of this malady and mortality rates in rats. Following administration of bacterial lipopolysaccharide (LPS; 5 or 18 mg/kg) or of a clinical Escherichia coli isolate (5 × 10(9) or 1 × 10(10) CFU/kg), hypothermia developed in rats exposed to a mildly cool environment, but not in rats exposed to a warm environment; only fever was revealed in the warm environment. Development of hypothermia instead of fever suppressed endotoxemia in E. coli-infected rats, but not in LPS-injected rats. The infiltration of the lungs by neutrophils was similarly suppressed in E. coli-infected rats of the hypothermic group. These potentially beneficial effects came with costs, as hypothermia increased bacterial burden in the liver. Furthermore, the hypotensive responses to LPS or E. coli were exaggerated in rats of the hypothermic group. This exaggeration, however, occurred independently of changes in inflammatory cytokines and prostaglandins. Despite possible costs, development of hypothermia lessened abdominal organ dysfunction and reduced overall mortality rates in both the E. coli and LPS models. By demonstrating that naturally occurring hypothermia is more advantageous than fever in severe forms of aseptic (LPS-induced) or septic (E. coli-induced) systemic inflammation, this study provides new grounds for the management of this deadly condition.
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Benefits of predischarge echocardiography service for postnatal heart murmurs.
Acta Paediatr.
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To review the findings and outcomes of predischarge echocardiography service for postnatal heart murmurs provided by neonatologists.
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JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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