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Find video protocols related to scientific articles indexed in Pubmed.
Replication study of previous migraine genome-wide association study findings in a Spanish sample of migraine with aura.
Cephalalgia
PUBLISHED: 11-13-2014
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Migraine is a common disabling condition that affects approximately 15% of the population. Several genome-wide association studies have attempted to identify susceptibility variants involved in migraine, reporting several candidate loci for the disorder.
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Acute mononeuropathy in a child with newly diagnosed type 1 diabetes mellitus.
J. Pediatr. Endocrinol. Metab.
PUBLISHED: 08-19-2014
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Abstract Introduction: Neuropathy is a frequent complication of diabetes mellitus (DM), increasing with the duration of the disease, poor glycemic control and advanced age. Acute presentation of a neuropathy in the setting of a newly diagnosed type 1 DM is rare and holds a diagnostic challenge. Case report: A 10-year-old girl, presented at the emergency service with complaints of polydipsia, polyuria, asthenia and weight lost over the last 15 days, accompanied by difficulties in flexing the right foot, during the previous week. The patient denied any pain, paresthesias, or altered sensibility. There was no fever documented, or recent infectious intercurrence or trauma. On physical examination, she was conscious, collaborative and space and time-orientated, had a diminished strength in the right foot, namely in the dorsiflexion, conditioning a steppage gait ipsilateral. Hyperalgesia was felt in the dorsum of the right feet to the ankle. DM type 1 was diagnosed based on serum glucose of 629 mg/dL and mild ketoacidosis. Investigation for infectious, immune and nutritional aetiologies for the mononeuropathy was negative. Electrophysiological study was suggestive of a lesion of the peroneal nerve on the popliteal cesspit, but was not conclusive. The patient started physiotherapy during her hospital stay and exhibited a slight improvement in the dorsiflexion of the foot. Four months later she was asymptomatic and with good glycaemic control. Conclusion: Diabetic neuropathy is a heterogeneous group that still lacks adequate comprehension. Its approach is empirical and demands exclusion of other etiologies. A definitive diagnosis is not always possible and sometimes is retrospective.
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Structural and functional stabilization of protein entities: State-of-the-art.
Adv. Drug Deliv. Rev.
PUBLISHED: 08-03-2014
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Within the context of biomedicine and pharmaceutical sciences, the issue of (therapeutic) protein stabilization assumes particular relevance. Stabilization of protein and protein-like molecules translates into preservation of both structure and functionality during storage and/or targeting, and such stabilization is mostly attained through establishment of a thermodynamic equilibrium with the (micro)environment. The basic thermodynamic principles that govern protein structural transitions and the interactions of the protein molecule with its (micro)environment are, therefore, tackled in a systematic fashion. Highlights are given to the major classes of (bio)therapeutic molecules, viz. enzymes, recombinant proteins, (macro)peptides, (monoclonal) antibodies and bacteriophages. Modification of the microenvironment of the biomolecule via multipoint covalent attachment onto a solid surface followed by hydrophylic polymer co-immobilization, or physical containment within nanocarriers, are some of the (latest) strategies discussed aiming at full structural and functional stabilization of said biomolecules.
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Biomimetic aqueous-core lipid nanoballoons integrating a multiple emulsion formulation: A suitable housing system for viable lytic bacteriophages.
Colloids Surf B Biointerfaces
PUBLISHED: 06-03-2014
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The emergence of antibiotic-resistant bacterial strains and the weak penetration of antibiotics into bacterial biofilms put an emphasis in the need for safe and effective alternatives for antimicrobial treatments. The application of strictly lytic bacteriophages (or phages) has been proposed as an alternative (or complement) to conventional antibiotics, allowing release of the natural predators of bacteria directly to the site of infection. In the present research effort, production of bacteriophage derivatives (starting from lytic phage particle isolates), encompassing full stabilization of their three-dimensional structure, has been attempted via housing said bacteriophage particles within lipid nanovesicles integrating a multiple water-in-oil-in-water (W/O/W) emulsion. As a proof-of-concept for the aforementioned strategy, bacteriophage particles with broad lytic spectrum were entrapped within the aqueous core of lipid nanoballoons integrating a W/O/W multiple emulsion. Long-term storage of the multiple emulsions produced did not lead to leaching of phage particles, thus proving the effectiveness of the encapsulation procedure.
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Development and characterization of a hydrogel containing nitrofurazone for antimicrobial topical applications.
Curr Pharm Biotechnol
PUBLISHED: 05-24-2014
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The goal of the research work entertained herein was the development and characterization of a poly-(vinyl alcohol) (PVA) hydrogel cross-linked with glutaraldehyde and impregnated with 0.2% (w/w) nitrofurazone (NTZ), for topical applications. To verify the active principle release capability, one has determined (i) swelling profile, (ii) in vitro release of NTZ via UV-VIS spectrophotometry, and (iii) antimicrobial activity via exposure to the hydrogel of ATCC strains of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The optimized hydrogel was further characterized via scanning electron microscopy (SEM), infrared spectroscopy with Fourier transform, moisture content determinations and thermal analyses via thermal gravimetry (TGA). Swelling tests revealed a mass increase from 100±5% up to 350±11%. Incorporated NTZ displayed bactericidal activity, as expected, being released in a linearly controlled fashion above 6 µg/mL during experiment timeframes of 14 h. SEM analyses allowed verification of a homogeneous surface morphology, while infrared spectra showed that NTZ did not bind strongly to the cross-linked polymer. Furthermore, results from thermal analyses suggested a loss of thermal stability arising from incorporation of NTZ in the hydrogel. The optimized hydrogel exhibited characteristics with high potential for (antimicrobial) treatment of skin lesions.
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Telomeric repeat-containing RNA (TERRA) and telomerase are components of telomeres during mammalian gametogenesis.
Biol. Reprod.
PUBLISHED: 04-09-2014
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Telomeres are ribonucleoprotein structures at the end of chromosomes composed of telomeric DNA, specific-binding proteins, and noncoding RNA (TERRA). Despite their importance in preventing chromosome instability, little is known about the cross talk between these three elements during the formation of the germ line. Here, we provide evidence that both TERRA and the telomerase enzymatic subunit (TERT) are components of telomeres in mammalian germ cells. We found that TERRA colocalizes with telomeres during mammalian meiosis and that its expression progressively increases during spermatogenesis until the beginning of spermiogenesis. While both TERRA levels and distribution would be regulated in a gender-specific manner, telomere-TERT colocalization appears to be regulated based on species-specific characteristics of the telomeric structure. Moreover, we found that TERT localization at telomeres is maintained throughout spermatogenesis as a structural component without affecting telomere elongation. Our results represent the first evidence of colocalization between telomerase and telomeres during mammalian gametogenesis.
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Telomere homeostasis is compromised in spermatocytes from patients with idiopathic infertility.
Fertil. Steril.
PUBLISHED: 04-07-2014
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To study whether the telomere structure of germ cells from idiopathic infertile men is altered and if this impairment is influenced by meiotic recombination and telomere length.
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Clinical and genetic analysis in alternating hemiplegia of childhood: ten new patients from Southern Europe.
J. Neurol. Sci.
PUBLISHED: 03-26-2014
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Alternating hemiplegia of childhood (AHC) is a rare neurodevelopmental disorder featuring attacks of hemiplegia and other paroxysmal and non-paroxysmal manifestations leading to progressive neurological impairment. De novo mutations in ATP1A3 have been identified in up to 80% of patients. AHC is also associated with rare mutations in other genes involved in episodic neurological disorders. We sought to find mutations in ATP1A3, CACNA1A, ATP1A2, SCN1A and SLC2A1 in a cohort of ten unrelated patients from Spain and Greece. All patients fulfilled AHC diagnostic criteria. All five genes were amplified by PCR and Sanger sequenced. Copy number variation (CNV) analysis of SLC2A1 and CACNA1A was performed using two different approaches. We identified three previously described heterozygous missense ATP1A3 mutations (p.Asp801Asn, p.Glu815Lys and p.Gly947Arg) in five patients. No disease-causing mutations were found in the remaining genes. All mutations occurred de novo; carriers presented on average earlier than non-carriers. Intellectual disability was more severe with the p.Glu815Lys variant. A p.Gly947Arg carrier harbored a maternally-inherited CACNA1A p.Ala454Thr variant. Of note, three of our patients exhibited remarkable clinical responses to the ketogenic diet. We confirmed ATP1A3 mutations in half of our patients. Further AHC genetic studies will need to investigate large rearrangements in ATP1A3 or consider greater genetic heterogeneity than previously suspected.
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Development and characterization of a gel formulation integrating microencapsulated nitrofurazone.
Curr Pharm Biotechnol
PUBLISHED: 01-18-2014
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Nitrofurazone (NTZ) is usually employed in the topical treatment of infected wounds and lesions of both skin and mucosa. Microencapsulation is a process utilized in the incorporation of active ingredients within polymers aiming at, among other objectives, the prolonged release of pharmaceutical compounds and protection from atmospheric agents (viz. moisture, light, heat and/or oxidation). With the goal of utilizing the microparticles containing encapsulated NTZ in pharmaceutical formulations, one prepared microparticles containing NTZ via ionotropic gelation of sodium alginate. The microparticles were characterized via scanning electron microscopy analyses, Fourier transform infrared spectroscopy (FTIR) analyses, via determination of encapsulation efficiency, and via thermal analyses (both TGA and DSC). The final gel formulation was also characterized rheologically. The extrusion/solidification technique employed to obtain the calcium alginate microparticles with encapsulated NTZ was found to be adequate, and produced an NTZ encapsulation efficiency of ca. 97.8% ± 1.1%. The calcium alginate microparticles thus obtained, with encapsulated NTZ, exhibited an oval shape and hydrodynamic diameters between 500 ?m and 800 ?m. From the thermal analyses performed, together with information from the infrared spectra, one may conclude that NTZ did not strongly bind to the polymer, which may be favorable for the release of the active ingredient. From the results obtained in the present research effort, one may conclude that the microparticles produced possess the potential to be utilized as carriers for NTZ in pharmaceutical formulations such as gels, ointments, and solutions.
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A loss-of-function CACNA1A mutation causing benign paroxysmal torticollis of infancy.
Eur. J. Paediatr. Neurol.
PUBLISHED: 01-08-2014
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Benign paroxysmal torticollis of infancy (BPTI) is a rare paroxysmal disorder characterized by recurrent episodes of head tilt and accompanying general symptoms which remit spontaneously. The rare association with gain-of-function CACNA1A mutations, similar to hemiplegic migraine, has been reported. We report here two new BPTI patients from the same family carrying a heterozygous mutation in the CACNA1A gene leading to the change p.Glu533Lys. Functional analysis revealed that this mutation induces a loss of channel function due to impaired gating by voltage and much lower current density. Our data suggest that BPTI, a periodic syndrome commonly considered a migraine precursor, constitutes an age-specific manifestation of defective neuronal calcium channel activity.
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Modulation of the fibrillogenesis inhibition properties of two transthyretin ligands by halogenation.
J. Med. Chem.
PUBLISHED: 11-07-2013
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The amyloidogenic protein transthyretin (TTR) is thought to aggregate into amyloid fibrils by tetramer dissociation which can be inhibited by a number of small molecule compounds. Our analysis of a series of crystallographic protein-inhibitor complexes has shown no clear correlation between the observed molecular interactions and the in vitro activity of the inhibitors. From this analysis, it emerged that halogen bonding (XB) could be mediating some key interactions. Analysis of the halogenated derivatives of two well-known TTR inhibitors has shown that while flufenamic acid affinity for TTR was unchanged by halogenation, diflunisal gradually improves binding up to 1 order of magnitude after iodination through interactions that can be interpreted as a suboptimal XB (carbonyl Thr106: I...O distance 3.96-4.05 Å; C-I...O angle 152-156°) or as rather optimized van der Waals contacts or as a mixture of both. These results illustrate the potential of halogenation strategies in designing and optimizing TTR fibrillogenesis inhibitors.
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Development of a buccal mucoadhesive film for fast dissolution: mathematical rationale, production and physicochemical characterization.
Drug Deliv
PUBLISHED: 11-05-2013
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Abstract The validity of a mathematical rationale for preparation of a fast-dissolving buccal mucoadhesive was tested. A buccal mucoadhesive biopolymeric formulation has been developed having pullulan as the main component. The formulation was duly evaluated physicochemically, via assays for intrinsic viscosity (resulting in 71.61?cm(3)?g(-1)), differential scanning calorimetry analysis (resulting in a Tg?=?63?°C), thermogravimetric analysis (244-341?°C), moisture content determinations (14%, w/w), dissolution timeframe (41.6?s), mucoadhesion force (40?kg/cm(2)), scanning electron microscopy analyses (critical ray under 1.0??m), mechanic strength (tensile strength?=?58?N/mm(2), deformation?=?4.4%). The mucoadhesive formulation exhibited important characteristics for a drug carrier, that is, a 6?cm(2) area, a fast dissolution timeframe, an adequate mucoadhesivity, resistance to both oxygen and water vapor penetration, increased viscosity in solution (ranging from 33.2?cm(3)/g to 71.61?cm(3)/g), easy molding, suitable water solubility and transparency.
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A Portuguese case of Hirayama disease.
BMJ Case Rep
PUBLISHED: 10-30-2013
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Hirayama disease, also known as monomelic amyotrophy or juvenile spinal muscular atrophy of the distal upper extremity features the impairment of the anterior horn cells of the distal cervical spinal cord secondary to dural sac anterior displacement during cervical flexion. We describe a case of a 17-year-old boy with a history of scoliosis, evaluated in the emergency department for decreased muscle strength and atrophy of the left upper limb with progressive worsening for about 6 months. We performed electrophysiological studies that showed severe neurogenic atrophy involving the C7-T1 left myotomes. Brain and spine MRI performed showed flattening of the lower cervical cord and dura mater anterior displacement during cervical flexion. These findings were consistent with the diagnosis of Hirayama disease.
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[Adaptation and validation of CAMDEX-DS (Cambridge Examination for Mental Disorders of Older People with Downs Syndrome and others with intellectual disabilities) in Spanish population with intellectual disabilities].
Rev Neurol
PUBLISHED: 10-02-2013
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Dementia caused by Alzheimers disease commonly affects the adult population with Downs syndrome. This population presents two characteristic clinical features: a semiologic pattern that differs from the typical Alzheimers disease, and previous intellectual deficits that may confound the clinical diagnosis. There is a clear need to validate specific instruments adapted to Spanish population.
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Carbohydrate Hydrogels with Stabilized Phage Particles for Bacterial Biosensing: Bacterium Diffusion Studies.
Appl. Biochem. Biotechnol.
PUBLISHED: 07-22-2013
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Bacteriophage particles have been reported as potentially useful in the development of diagnosis tools for pathogenic bacteria as they specifically recognize and lyse bacterial isolates thus confirming the presence of viable cells. One of the most representative microorganisms associated with health care services is the bacterium Pseudomonas aeruginosa, which alone is responsible for nearly 15 % of all nosocomial infections. In this context, structural and functional stabilization of phage particles within biopolymeric hydrogels, aiming at producing cheap (chromogenic) bacterial biosensing devices, has been the goal of a previous research effort. For this, a detailed knowledge of the bacterial diffusion profile into the hydrogel core, where the phage particles lie, is of utmost importance. In the present research effort, the bacterial diffusion process into the biopolymeric hydrogel core was mathematically described and the theoretical simulations duly compared with experimental results, allowing determination of the effective diffusion coefficients of P. aeruginosa in the agar and calcium alginate hydrogels tested.
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Cancer stem cells maintain a hierarchy of differentiation by creating their niche.
Int. J. Cancer
PUBLISHED: 06-07-2013
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The self-renewal and differentiation properties of cancer stem cells (CSCs) are regulated and maintained by the CSC niche. However, the mechanism of this maintenance, especially the maintenance contributed by differentiated cancer cells, remains to be fully elucidated. Recently, we have established a model of CSCs, miPS-LLCcm, from mouse induced pluripotent stem cells (miPSCs). In vitro cultured miPS-LLCcm cells were autonomously balanced with stem-like cells and differentiated cells including vascular endothelial cells. Under these conditions, the CSC properties appeared to be stable in the presence of the factor(s) secreted by the differentiated cells. The factor(s) activated Notch signaling and promoted self-renewal of CSCs. In addition, the secreted factor(s) appeared to regulate the differentiation lineage of CSCs. Our results indicate that the differentiated progenies of CSCs containing vascular endothelium play important roles for regulating the CSCs properties. Therefore, miPS-LLCcm cells create their own in vitro niche to maintain themselves in the hierarchy of differentiating CSCs.
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Biallelic SZT2 mutations cause infantile encephalopathy with epilepsy and dysmorphic corpus callosum.
Am. J. Hum. Genet.
PUBLISHED: 04-30-2013
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Epileptic encephalopathies are genetically heterogeneous severe disorders in which epileptic activity contributes to neurological deterioration. We studied two unrelated children presenting with a distinctive early-onset epileptic encephalopathy characterized by refractory epilepsy and absent developmental milestones, as well as thick and short corpus callosum and persistent cavum septum pellucidum on brain MRI. Using whole-exome sequencing, we identified biallelic mutations in seizure threshold 2 (SZT2) in both affected children. The causative mutations include a homozygous nonsense mutation and a nonsense mutation together with an exonic splice-site mutation in a compound-heterozygous state. The latter mutation leads to exon skipping and premature termination of translation, as shown by RT-PCR in blood RNA of the affected boy. Thus, all three mutations are predicted to result in nonsense-mediated mRNA decay and/or premature protein truncation and thereby loss of SZT2 function. Although the molecular role of the peroxisomal protein SZT2 in neuronal excitability and brain development remains to be defined, Szt2 has been shown to influence seizure threshold and epileptogenesis in mice, consistent with our findings in humans. We conclude that mutations in SZT2 cause a severe type of autosomal-recessive infantile encephalopathy with intractable seizures and distinct neuroradiological anomalies.
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Efficiency of different heterologous promoters in the unicellular microalga Chlamydomonas reinhardtii.
Biotechnol. Prog.
PUBLISHED: 03-06-2013
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Despite the biotechnological interest of microalgae, no robust and stable methods for genetic transformation of most microalgal strains exist. The scanty and disperse data about the efficiency of heterologous promoters in microalgae and the use of different transformation methods, DNA quantities and reporter genes in the existing studies makes very difficult a real comparison of their efficiency. Using Chlamydomonas reinhardtii as a host, we have evaluated the efficiency of the heterologous promoters of cauliflower mosaic virus 35S (CaMV 35S) and Agrobacterium nopaline synthase (NOS) genes. These promoters were fused to the paromomycin conferring-resistance aminoglycoside 3-phosphotransferase encoding gene (APHVIII), and C. reinhardtii was transformed by the glass beads agitation method. The transformation efficiency and the APHVIII transcript and protein levels were evaluated in a series of transformants for each promoter. The chimeric promoter HSP70A/RBCS2 and the promoter-less APHVIII marker gene were used for comparison. We found significantly higher transformation efficiencies and higher level of APHVIII expression in those transformants harboring the NOS promoter than in those transformed with CaMV 35S promoter. The NOS promoter, widely used for genetic manipulation of higher plants, has been very rarely used for the transformation of microalgae. The results shown here suggest the possibilities of this heterologous promoter as an efficient system for the genetic manipulation of microalgae.
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Structural and functional stabilization of phage particles in carbohydrate matrices for bacterial biosensing.
Enzyme Microb. Technol.
PUBLISHED: 01-17-2013
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Infections associated with health care services are nowadays widespread and, associated to the progressive emergence of microorganisms resistant to conventional chemical antibiotics, are major causes of morbidity and mortality. One of the most representative microorganisms in this scenario is the bacterium Pseudomonas aeruginosa, which alone is responsible for ca. 13-15% of all nosocomial infections. Bacteriophages have been reported as a potentially useful tool in the diagnosis of bacterial diseases, since they specifically recognize and lyse bacterial isolates thus confirming the presence of viable cells. In the present research effort, immobilization of these biological (although metabolically inert) entities was achieved via entrapment within (optimized) porous (bio)polymeric matrices of alginate and agar, aiming at their full structural and functional stabilization. Such phage-impregnated polymeric matrices are intended for future use as chromogenic hydrogels sensitive to color changes evolving from reaction with (released) intracytoplasmatic moieties, as a detection kit for P. aeruginosa cells.
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Causes and evolutionary consequences of population subdivision of an Iberian mountain lizard, Iberolacerta monticola.
PLoS ONE
PUBLISHED: 01-01-2013
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The study of the factors that influence population connectivity and spatial distribution of genetic variation is crucial for understanding speciation and for predicting the effects of landscape modification and habitat fragmentation, which are considered severe threats to global biodiversity. This dual perspective is obtained from analyses of subalpine mountain species, whose present distribution may have been shaped both by cyclical climate changes over ice ages and anthropogenic perturbations of their habitats. Here, we examine the phylogeography, population structure and genetic diversity of the lacertid lizard Iberolacerta monticola, an endemism considered to be facing a high risk of extinction in several populations.
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Complex evolutionary history of the Mexican stoneroller Campostoma ornatum Girard, 1856 (Actinopterygii: Cyprinidae).
BMC Evol. Biol.
PUBLISHED: 06-04-2011
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Studies of the phylogeography of Mexican species are steadily revealing genetic patterns shared by different species, which will help to unravel the complex biogeographic history of the region. Campostoma ornatum is a freshwater fish endemic to montane and semiarid regions in northwest Mexico and southern Arizona. Its wide range of distribution and the previously observed morphological differentiation between populations in different watersheds make this species a useful model to investigate the biogeographic role of the Sierra Madre Occidental and to disentangle the actions of Pliocene tecto-volcanic processes vs Quaternary climatic change. Our phylogeographic study was based on DNA sequences from one mitochondrial gene (cytb, 1110 bp, n=285) and two nuclear gene regions (S7 and RAG1, 1822 bp in total, n=56 and 43, respectively) obtained from 18 to 29 localities, in addition to a morphological survey covering the entire distribution area. Such a dataset allowed us to assess whether any of the populations/lineages sampled deserve to be categorised as an evolutionarily significant unit.
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Development and evaluation of a floating multiparticulate gastroretentive system for modified release of AZT.
AAPS PharmSciTech
PUBLISHED: 04-27-2011
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The aim of this study was to develop and evaluate a floating multiparticulate gastroretentive system for the modified release of zidovudine (AZT). AZT was used as a model drug water-soluble at therapeutic doses. The floating gastroretentive system was obtained by co-precipitation, after solvent diffusion and evaporation. The proposed system was evaluated in vitro for particle morphology, lag time and floating time, loading rate, release profile, and the release kinetic of AZT release. AZTs physico-chemical characteristics were evaluated by differential scanning calorimetry (DSC), X-ray diffraction (XDR) and infrared spectroscopy (IR). The particles obtained were sphere-shaped, hollow, and had porous walls. The floating was immediate, and floating time was higher than 12 h. The loading rate was 34.0 ± 9.0%. The system obtained had an extended release. DSC and XDR results showed a modification in AZTs solid state. IR spectroscopy revealed that the chemical structure of the AZT was unchanged. The hollow microballoons presented gastroretentive, floating, and extended-release properties.
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Identification of the sex pheromone of a protected species, the Spanish moon moth Graellsia isabellae.
J. Chem. Ecol.
PUBLISHED: 04-30-2010
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Sex attractant pheromones are highly sensitive and selective tools for detecting and monitoring populations of insects, yet there has been only one reported case of pheromones being used to monitor protected species. Here, we report the identification and synthesis of the sex pheromone of a protected European moth species, Graellsia isabellae (Lepidoptera: Saturniidae), as the single component, (4E,6E,11Z)-hexadecatrienal. In preliminary field trials, lures loaded with this compound attracted male moths from populations of this species at a number of widely separated field sites in France, Switzerland, and Spain, clearly demonstrating the utility of pheromones in sampling potentially endangered insect species.
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Quantitative spot-test analysis of metformin in pharmaceutical preparations using ultraviolet-visible diffuse reflectance spectroscopy.
Anal Sci
PUBLISHED: 01-13-2010
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A quantitative spot-test for the determination of metformin in pharmaceutical preparations using diffuse UV-visible reflectance is reported. The procedure is quite simple, involving in the formation of a metformin-nickel(II) complex on a glass filter membrane with a later measurement of the reflectance in the spectrophotometer using an integration sphere. The analytical results obtained with commercial products were statistically compared with those resulting from a method recommended by JP and by USP, where complete agreement was observed. The average RSD is 2.5% and the detection (0.009 mol L(-1)) and the quantitation (0.03 mol L(-1)) limits are quite adequate for pharmaceutical analysis.
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Eosinophil cationic protein enhances stabilization of ?-catenin during cardiomyocyte differentiation in P19CL6 embryonal carcinoma cells.
Mol. Biol. Rep.
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Prior to gastrulation, the Wnt signaling pathway through stabilized ?-catenin enhances the differentiation of mouse ES cell into cardiomyocytes. We have recently shown that cardiomyocyte differentiation is enhanced by eosinophil cationic protein (ECP) through accelerated expression of marker genes of early cardiac differentiation. Furthermore, ECP enhanced the expression of Wnt3a in P19CL6 cells which were stimulated to differentiate into cardiomyocytes by DMSO. Following these findings, we evaluated in this study the potential of ECP to activate the Wnt/?-catenin signaling pathway during cardiomyocyte differentiation. Analysis by real time qPCR revealed that ECP increased the expression of Frizzled genes such as Frizzled-1, -2, -4 and -10 in P19CL6 cells in the presence of DMSO. The increased expression of those Wnt receptors was found to inhibit the phosphorylation of ?-catenin resulting in the stabilization and translocation of ?-catenin into the nucleus of P19CL6 cells during the early stages of cardiomyocyte differentiation. When assessed for ?-catenin/TCF transcriptional activity with a TCF-luciferase (TOP/FOP) assay, ECP enhanced luciferase activity in P19CL6 cells during 48 h after transfection with TOP/FOP flash reporter in a stoichiometric manner. Collectively, this suggests that ECP can activate a canonical Wnt/?-catenin signaling pathway by enhancing the stabilization of ?-catenin during cardiomyocyte differentiation.
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Promoter trapping in microalgae using the antibiotic paromomycin as selective agent.
Mar Drugs
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The lack of highly active endogenous promoters to drive the expression of transgenes is one of the main drawbacks to achieving efficient transformation of many microalgal species. Using the model chlorophyte Chlamydomonas reinhardtii and the paromomycin resistance APHVIII gene from Streptomyces rimosus as a marker, we have demonstrated that random insertion of the promoterless marker gene and subsequent isolation of the most robust transformants allows for the identification of novel strong promoter sequences in microalgae. Digestion of the genomic DNA with an enzyme that has a unique restriction site inside the marker gene and a high number of target sites in the genome of the microalga, followed by inverse PCR, allows for easy determination of the genomic region, which precedes the APHVIII marker gene. In most of the transformants analyzed, the marker gene is inserted in intragenic regions and its expression relies on its adequate insertion in frame with native genes. As an example, one of the new promoters identified was used to direct the expression of the APHVIII marker gene in C. reinhardtii, showing high transformation efficiencies.
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Genome-wide association analysis identifies susceptibility loci for migraine without aura.
Nat. Genet.
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Migraine without aura is the most common form of migraine, characterized by recurrent disabling headache and associated autonomic symptoms. To identify common genetic variants associated with this migraine type, we analyzed genome-wide association data of 2,326 clinic-based German and Dutch individuals with migraine without aura and 4,580 population-matched controls. We selected SNPs from 12 loci with 2 or more SNPs associated with P values of <1 × 10(-5) for replication testing in 2,508 individuals with migraine without aura and 2,652 controls. SNPs at two of these loci showed convincing replication: at 1q22 (in MEF2D; replication P = 4.9 × 10(-4); combined P = 7.06 × 10(-11)) and at 3p24 (near TGFBR2; replication P = 1.0 × 10(-4); combined P = 1.17 × 10(-9)). In addition, SNPs at the PHACTR1 and ASTN2 loci showed suggestive evidence of replication (P = 0.01; combined P = 3.20 × 10(-8) and P = 0.02; combined P = 3.86 × 10(-8), respectively). We also replicated associations at two previously reported migraine loci in or near TRPM8 and LRP1. This study identifies the first susceptibility loci for migraine without aura, thereby expanding our knowledge of this debilitating neurological disorder.
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Ketocarotenoid biosynthesis in transgenic microalgae expressing a foreign ?-C-4-carotene oxygenase gene.
Methods Mol. Biol.
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Ketocarotenoids are obtained by the action of the ?-carotene ketolase, which catalyses the addition of a keto-group at the C4 position of carotenoids ?-ion-rings. Most microalgae and higher plants do not posses the carotene ketolase activity and consequently do not synthesize ketocarotenoids, which are highly demanded as feed supplements and as nutraceutical for human nutrition. Here we propose the use of the unicellular microalga Chlamydomonas reinhardtii to express the Bkt (?-carotene ketolase) gene from Haematococcus pluvialis and synthesize a new ketocarotenoid that the vegetative cells of Chlamydomonas do not synthesize in the natural way. The methodology needed to successfully achieve metabolic engineering of ketocarotenoids synthesis in Chlamydomonas is described in this chapter, including the construction of a vector containing the Bkt gene, transformation of Chlamydomonas, selection of transformants, and carotenoids analysis.
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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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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.