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1.
Int J Syst Evol Microbiol ; 69(10): 2992-3000, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31166162

RESUMEN

The Arabian Gulf surrounding Qatar is distinct from other marine ecosystems due to its high salinity (35-75 PSU) and extreme water temperature fluctuations (11-40 °C). Furthermore, in the last decade, Qatar has been witnessing an industrial boom as well as extensive infrastructure construction activities. Marine micro-organisms, including fungi, remain largely unexplored in the Arabian Gulf. During a 3 year study, we investigated the diversity of marine fungi in coastal waters around Qatar. As a result, two new Toxicocladosporium species were isolated from the Qatari marine environment. Molecular and phylogenetic analyses of rRNA gene sequences of five loci, namely the internal transcribed spacer 1 and 2 regions and the D1/D2 domains of the large subunit rRNA, actin, RNA polymerase second largest subunit and beta-tubulin genes, were used to confirm the identity of the novel species for which we propose the names Toxicocladosporium aquimarinum sp. nov. and Toxicocladosporium qatarense sp. nov.


Asunto(s)
Ascomicetos/clasificación , Filogenia , Agua de Mar/microbiología , Ascomicetos/aislamiento & purificación , ADN de Hongos/genética , ADN Espaciador Ribosómico/genética , Ecosistema , Técnicas de Tipificación Micológica , Qatar , Salinidad , Análisis de Secuencia de ADN
2.
J Appl Microbiol ; 125(2): 480-489, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29704883

RESUMEN

AIMS: Immobilization of microbial cells is a useful strategy for developing high cell density bioreactors with improved stability and productivity for production of different chemicals. Functionalization of the immobilization matrix or biofilm forming property of some strains has been utilized for achieving cell attachment. The aim of the present study was to investigate the production of exopolysaccharide (EPS) by Propionibacterium freudenreichii C.I.P 59.32 and utilize this feature for immobilization of the cells on porous glass beads for production of propionic acid. METHODS AND RESULTS: Propionibacterium freudenreichii was shown to produce both capsular and excreted EPS during batch cultivations using glucose as carbon source. Different electron microscopy techniques confirmed the secretion of EPS and formation of cellular aggregates. The excreted EPS was mainly composed of mannose and glucose in a 5·3 : 1 g g-1 ratio. Immobilization of the cells on untreated and polyethyleneimine (PEI)-treated Poraver beads in a bioreactor was evaluated. Higher productivity and yield of propionic acid (0·566 g l-1  h-1 and 0·314 g g-1 , respectively) was achieved using cells immobilized to untreated beads and EPS production reached 617·5 mg l-1 after 48 h. CONCLUSION: These results suggest an important role of EPS-producing strains for improving cell immobilization and propionic acid production. SIGNIFICANCE AND IMPACT OF THE STUDY: This study demonstrates the EPS-producing microbe to be easily immobilized on a solid matrix and to be used in a bioprocess. Such a system could be optimized for achieving high cell density in fermentations without the need for functionalization of the matrix.


Asunto(s)
Reactores Biológicos/microbiología , Células Inmovilizadas , Polisacáridos Bacterianos/metabolismo , Propionatos , Propionibacterium freudenreichii , Células Inmovilizadas/citología , Células Inmovilizadas/metabolismo , Propionatos/análisis , Propionatos/metabolismo , Propionibacterium freudenreichii/citología , Propionibacterium freudenreichii/metabolismo
3.
J Infect Dis ; 215(9): 1366-1375, 2017 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-28201724

RESUMEN

Background: Genital inflammation is a key determinant of human immunodeficiency virus (HIV) transmission, and may increase HIV-susceptible target cells and alter epithelial integrity. Several genital conditions that increase HIV risk are more prevalent in African, Caribbean, and other black (ACB) women, including bacterial vaginosis and herpes simplex virus type-2 (HSV-2) infection. Therefore, we assessed the impact of the genital microbiota on mucosal immunology in ACB women and microbiome-HSV-2 interactions. Methods: Cervicovaginal secretions and endocervical cells were collected by cytobrush and Instead Softcup, respectively. T cells and dendritic cells were assessed by flow cytometry, cytokines by multiplex enzyme-linked immunosorbent assay (ELISA), and the microbiota by 16S ribosomal ribonucleic acid gene sequencing. Results: The cervicovaginal microbiota of 51 participants were composed of community state types (CSTs) showing diversity (20/51; 39%) or predominated by Lactobacillus iners (22/51; 42%), L. crispatus (7/51; 14%), or L. gasseri (2/51; 4%). High-diversity CSTs and specific bacterial phyla (Gardnerella vaginalis and Prevotella bivia) were strongly associated with cervicovaginal inflammatory cytokines, but not with altered endocervical immune cells. However, cervical CD4+ T-cell number was associated with HSV-2 infection and a distinct cytokine profile. Conclusions: This suggests that the genital microbiota and HSV-2 infection may influence HIV susceptibility through independent biological mechanisms.


Asunto(s)
Cuello del Útero , Herpes Genital , Microbiota/inmunología , Vagina , Adulto , Anciano , Cuello del Útero/citología , Cuello del Útero/inmunología , Cuello del Útero/microbiología , Cuello del Útero/virología , Estudios de Cohortes , Citocinas/análisis , Citocinas/inmunología , Femenino , Herpes Genital/inmunología , Herpes Genital/microbiología , Herpes Genital/virología , Humanos , Inmunidad Mucosa/inmunología , Persona de Mediana Edad , Vagina/inmunología , Vagina/microbiología , Vagina/virología , Adulto Joven
4.
J Appl Microbiol ; 121(1): 115-25, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-27028513

RESUMEN

AIMS: Bacterial infection is a major challenge in wound care. Antimicrobial wound dressings are of great value for treating wound infections. Endolysins are evolving as a new class of antimicrobials with multiple applications. This study describes the production and evaluation of T4 lysozyme (T4Lyz), product of gene e of the T4 bacteriophage, fused with Cellulose Binding Module (CBM) for facile immobilization to cellulosic wound dressing. METHODS AND RESULTS: Genes encoding T4Lyz-CBM and T4Lyz were cloned and expressed in Escherichia coli and the enzymes were purified by cation exchange chromatography. While the CBM tag did not alter the optimum pH and stability features of T4Lyz, the lytic activity of the fusion protein was lowered. The bactericidal activity of T4Lyz-CBM, determined by viable count plating assay after 1 h incubation with Micrococcus lysodeikticus was 97·5% with 10 µg ml(-1) , and 99·96% and 95% for E. coli and Pseudomonas mendocina, respectively, with 200 µg ml(-1) enzyme. T4Lyz-CBM was immobilized to wound dressing gauze with a capacity of 5·5 µg mg(-1) matrix, whereas the unmodified T4Lyz did not exhibit any binding. The immobilized protein retained its bactericidal activity against Gram-positive and Gram-negative bacteria. Both free and immobilized T4Lyz-CBM, after heat denaturation, retained their bactericidal activities against Gram-negative bacteria only. The immobilized enzyme exhibited higher stability than the free enzyme when stored in dry form or in the presence of polyol stabilizers. CONCLUSION: Tagging T4Lyz with CBM provides a facile, irreversible binding to cellulosic wound dressing while retaining its activity. This approach may be suitable even for other antimicrobial enzymes and -peptides. SIGNIFICANCE AND IMPACT OF THE STUDY: The spread of antibiotic resistance requires innovative strategies for discovery and development of effective antimicrobial alternatives. This report presents a novel strategy for producing antimicrobial wound dressing materials.


Asunto(s)
Antiinfecciosos/farmacología , Bacteriófago T4/enzimología , Vendajes , Celulosa/química , Enzimas Inmovilizadas/farmacología , Muramidasa/farmacología , Antiinfecciosos/química , Antiinfecciosos/metabolismo , Farmacorresistencia Microbiana , Estabilidad de Enzimas , Escherichia coli/genética , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Muramidasa/química , Infección de Heridas/microbiología , Infección de Heridas/prevención & control
5.
Cell Mol Biol (Noisy-le-grand) ; 61(5): 36-44, 2015 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-26475386

RESUMEN

Abrin, a phytotoxin obtained from the seeds of the Abrus precatorius plant, is highly toxic with an estimated human fatal dose of 0.1­1 µg/kg. In this study, abrin was purified and characterized through SDS PAGE and mass spectrometry analysis; further study on toxicity was carried out to investigate the alteration in biochemical, and hematological variables through histopathological observations in mice. The intraperitoneal LD50 value of purified abrin for mice was found to be 0.91µg/kg of body weight. Mice were exposed to 0.4 and 1.0 LD50 abrin doses intraperitoneally and observed on days 1, 3, and 7. Plasma GOT and GPT levels increased significantly at both doses. At 1.0 LD50 dose, alkaline phosphatase, bilirubin, urea, uric acid, and creatinine levels increased, whereas albumin, total protein, glucose and cholesterol levels decreased significantly. Abrin intoxication also altered the hemoglobin, WBC, and RBC counts significantly at 1.0 LD50 dose. Liver GSH levels decreased while lipid peroxidation increased significantly in a dose­dependent manner. Biochemical changes were supported by the histological investigation, which also showed the degenerative changes in organs. In conclusion, abrin intoxication caused toxic effects and severe damages on studied organs mediated through alteration in biochemical and hematological variables, lipid peroxidation, and degeneration.


Asunto(s)
Abrina/toxicidad , Peroxidación de Lípido/fisiología , Hígado/patología , Estrés Oxidativo/efectos de los fármacos , Abrus/metabolismo , Animales , Peso Corporal/efectos de los fármacos , Glutatión/metabolismo , Dosificación Letal Mediana , Masculino , Espectrometría de Masas , Ratones , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismo
6.
Spinal Cord ; 53(1): 42-8, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25384403

RESUMEN

STUDY DESIGN: Online questionnaire survey. OBJECTIVE: To obtain the opinion of experts on whether the currently available classification systems for thoracolumbar and subaxial cervical spine injuries meet their expectations with regard to the desired objectives of a good classification system and practical implementability. METHODS: An online survey was conducted during August-September 2013 using a specially designed questionnaire. Members of Spine Trauma Study Group of International Spinal Cord Society and other spinal injury experts were approached, and responses were analyzed. RESULTS: Forty-two spine experts responded. Majority (87.50%, n=35) were involved with education and research. For subaxial cervical spine injuries, Allen Ferguson classification was more commonly used (37.50%, n=15) and thought to be practically implementable in day-to-day practice (30.77%). For thoracolumbar injuries, while Thoracolumbar Injury Classification and Severity Score (TLICS) was more commonly used (47.50%, n=19), the response of experts for practical implementability in day-to-day practice was more evenly distributed among TLICS, AO (Association for Osteosynthesis) and Dennis classifications (30.77, 23.08 and 25.64%, respectively). Experts felt that the classification systems did not serve all the desired objectives. The reliability for residents was especially a concern. CONCLUSION: We may still be far from an ideal classification system. Many experts continue to prefer or would consider shifting back to traditional and simpler systems. There is a need for developing classification systems that would be better implementable practically in day-to-day clinical practice, better guide treatment, be more reliable, incorporate other modifiers influencing treatment and be more comprehensive in that order of priority.


Asunto(s)
Testimonio de Experto , Vértebras Lumbares/lesiones , Índice de Severidad de la Enfermedad , Traumatismos de la Médula Espinal/clasificación , Traumatismos de la Médula Espinal/patología , Vértebras Torácicas/lesiones , Femenino , Humanos , Masculino , Sistemas en Línea , Encuestas y Cuestionarios
7.
Spinal Cord ; 53(5): 353-7, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25224600

RESUMEN

OBJECTIVE: This study aims to understand the demographics, mode of trauma, hospital stay, complications, neurological improvement, mortality and expenditure incurred by Indian patients with spinal trauma and ankylosing spondylitis (AS). METHODS: Retrospective analysis of the patient data admitted to a tertiary referral hospital from 2008 to 2013 with the diagnosis of AS and spinal trauma was carried out. The variables studied were demographics, mode of trauma, neurological status, neurological improvement, involved vertebral level, duration of hospital stay, comorbid factors, expenditure and complications during the stay. RESULTS: Forty-six patients with diagnosis of AS with spine trauma were admitted over the last 5 years with a total of 52 fractures. All were male patients; 58.6% had injury because of trivial trauma and 78.2% patients presented with neurological injury. C5 C6, C6 C7, C7 D1 and D12 were the most common injured level. Fractures through intervertebral disc were most common in cervical spine. Of the patients, 52.7% had shown neurological improvement of at least grade 1(AIS). Mean expenditure of patient admitted with spinal cord injury (SCI) with AS is 7957 USD (United States dollar), which is around five times the per capita income in India (as per year 2013). CONCLUSION: Males with AS are much more prone to spinal fractures than females and its incidence may be higher than previously reported. Domestic falls are the most common mechanism of spinal trauma in this population. High velocity injuries are associated with complete SCI. The study reinforces the need for development of subsidized spinal care services for SCI management.


Asunto(s)
Traumatismos de la Médula Espinal/complicaciones , Traumatismos de la Médula Espinal/epidemiología , Espondilitis Anquilosante/complicaciones , Espondilitis Anquilosante/epidemiología , Adulto , Anciano , Comorbilidad , Femenino , Hospitalización/estadística & datos numéricos , Humanos , Incidencia , India/epidemiología , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Factores Sexuales , Traumatismos de la Médula Espinal/economía , Traumatismos de la Médula Espinal/mortalidad , Espondilitis Anquilosante/economía , Espondilitis Anquilosante/mortalidad
8.
Phys Rev Lett ; 112(5): 056402, 2014 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-24580616

RESUMEN

We synthesize and study single crystals of a new double-perovskite Sr2YIrO6. Despite two strongly unfavorable conditions for magnetic order, namely, pentavalent Ir5+(5d4) ions which are anticipated to have Jeff=0 singlet ground states in the strong spin-orbit coupling (SOC) limit and geometric frustration in a face-centered cubic structure formed by the Ir5+ ions, we observe this iridate to undergo a novel magnetic transition at temperatures below 1.3 K. We provide compelling experimental and theoretical evidence that the origin of magnetism is in an unusual interplay between strong noncubic crystal fields, local exchange interactions, and "intermediate-strength" SOC. Sr2YIrO6 provides a rare example of the failed dominance of SOC in the iridates.

9.
Nat Genet ; 5(2): 118-23, 1993 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8252036

RESUMEN

Canavan disease, an autosomal recessive leukodystrophy, is caused by deficiency of aspartoacylase and accumulation of N-acetylaspartic acid in brain. We have cloned the human aspartoacylase (ASP) cDNA spanning 1,435 basepairs, and show that the isolated cDNA expresses aspartoacylase activity in bacteria. Furthermore, an A to C base change, at nucleotide 854, has been found in 85% of the 34 Canavan alleles tested so far. This base change results in a missense Glu285Ala mutation that is predicted to be part of the catalytic domain of aspartoacylase. The data suggest that the catalytic centre of aspartoacylase involves a triad of Ser, His and Glu residues. Our findings have implications for diagnosis and screening of Canavan disease.


Asunto(s)
Amidohidrolasas/genética , Enfermedad de Canavan/genética , Mutación , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Enfermedad de Canavan/diagnóstico , Bovinos , ADN Complementario , Humanos , Datos de Secuencia Molecular , Alineación de Secuencia
10.
Nature ; 441(7091): 315-21, 2006 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-16710414

RESUMEN

The reference sequence for each human chromosome provides the framework for understanding genome function, variation and evolution. Here we report the finished sequence and biological annotation of human chromosome 1. Chromosome 1 is gene-dense, with 3,141 genes and 991 pseudogenes, and many coding sequences overlap. Rearrangements and mutations of chromosome 1 are prevalent in cancer and many other diseases. Patterns of sequence variation reveal signals of recent selection in specific genes that may contribute to human fitness, and also in regions where no function is evident. Fine-scale recombination occurs in hotspots of varying intensity along the sequence, and is enriched near genes. These and other studies of human biology and disease encoded within chromosome 1 are made possible with the highly accurate annotated sequence, as part of the completed set of chromosome sequences that comprise the reference human genome.


Asunto(s)
Cromosomas Humanos Par 1/genética , Secuencia de Bases , Momento de Replicación del ADN , Enfermedad , Duplicación de Gen , Genes/genética , Variación Genética/genética , Genómica , Humanos , Datos de Secuencia Molecular , Sistemas de Lectura Abierta/genética , Seudogenes/genética , Recombinación Genética/genética , Selección Genética , Análisis de Secuencia de ADN
11.
Sex Transm Infect ; 87(2): 125-30, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21228419

RESUMEN

The sexual transmission of HIV is very inefficient, presumably because mucosal immune defences prevent infection after most exposures. Since numerous genital immune factors have antiviral effects in vitro, their elucidation might greatly inform the microbicide and HIV prevention fields, particularly in the context of HIV-exposed but persistently seronegative (ESN) individuals. However, several important confounders must be considered in such research. First, sound epidemiological criteria are needed to define individuals as ESN. Then, since high-risk sexual activity is commonly one of these criteria, its potential impact on genital immunology must be carefully considered, both the direct effects of sex and the secondary immune effects of genital co-infections. This means that it may be very difficult to determine whether differences in genital immunology between ESN and control groups are responsible for HIV protection, or are a consequence of high-risk sexual activity. To overcome this confounding, the demographics and epidemiology of ESN cohorts must be described very carefully, thorough co-infection diagnostics must be performed and, if possible, prospective studies with an endpoint of HIV acquisition should be performed to define the direction of causality.


Asunto(s)
Infecciones por VIH/inmunología , Inmunidad Mucosa/inmunología , Susceptibilidad a Enfermedades/inmunología , Femenino , Infecciones por VIH/transmisión , Seronegatividad para VIH/inmunología , Humanos , Factores Inmunológicos/inmunología , Masculino , Estudios Prospectivos , ARN Viral/sangre
12.
Br J Oral Maxillofac Surg ; 59(6): 700-704, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-34092410

RESUMEN

Maxillofacial injuries are usually not life-threatening and do not get priority over other associated injuries. However, some maxillofacial injuries with active oral or nasal bleeding need immediate management due to threatened airway and blood loss. In the case of major active vascular bleeding, measures such as local pressure, anterior nasal packing, posterior nasal packing, and balloon tamponade are ineffective. In these cases, angiography and transcatheter arterial embolisation (TAE) are used to treat life-threatening haemorrhage caused by maxillofacial trauma. We analysed the medical records of 39 patients with severe maxillofacial trauma and life-threatening haemorrhage that was a result of intractable oral or nasal bleeding. These patients were considered for TAE from January 2010 to December 2019. A total of 1668 patients was admitted, out of which 39 (2.3%) had severe maxillofacial injuries with life-threatening oral or nasal bleeding and underwent TAE. Out of a total of 39 patients, 38 were male and one female. Ages ranged from 16 to 65 years. Road traffic injury was the most common cause of injury (79.5%), Lefort I and II were the most common facial fractures, and traumatic brain injury was the most common associated injury. Embolisation and bleeding control were done successfully in all 39 patients with no procedure-related complications. A total of 17 deaths during the study period were due to severe traumatic brain injuries or haemorrhagic shock.


Asunto(s)
Traumatismos Maxilofaciales , Fracturas Craneales , Adolescente , Adulto , Atención de Apoyo Vital Avanzado en Trauma , Anciano , Epistaxis/etiología , Epistaxis/terapia , Femenino , Humanos , Masculino , Traumatismos Maxilofaciales/complicaciones , Traumatismos Maxilofaciales/terapia , Persona de Mediana Edad , Estudios Retrospectivos , Centros Traumatológicos , Adulto Joven
13.
J Microsc ; 240(1): 60-74, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21050214

RESUMEN

Dual-beam white light interference microscopy monitors changes in the optical density of the investigated object with high sensitivity. We report on the recording of dynamic changes in a neuron's optical density evoked by extracellular electrical stimulation. These recorded changes were analysed and unambiguously connected to the investigated object, an invertebrate neuron of the pond snail Lymnaea stagnalis. The results provide evidence for the method's applicability in visualizing cellular dynamics purely by evaluating changes in a cell's optical properties.


Asunto(s)
Potenciales de Acción , Microscopía de Interferencia/instrumentación , Microscopía de Interferencia/métodos , Neuronas/fisiología , Animales , Células Cultivadas , Estimulación Eléctrica , Ganglios de Invertebrados/citología , Ganglios de Invertebrados/fisiología , Lymnaea/citología , Lymnaea/fisiología , Neuronas/citología , Grabación en Video
14.
Sci Rep ; 10(1): 8514, 2020 05 22.
Artículo en Inglés | MEDLINE | ID: mdl-32444843

RESUMEN

The immunology and microbiota of the female genital tract (FGT) are key determinants of HIV susceptibility. Cervical cytobrush sampling is a relatively non-invasive method permitting the longitudinal assessment of endocervical immune cells, but effects on FGT immunology are unknown. Blood, cervico-vaginal secretions and cervical cytobrushes were collected from sexually transmitted infection (STI)-free women at baseline and after either 6 hours or 48 hours. Endocervical immune cell subsets were assessed by flow cytometry, and pro-inflammatory cytokines by multiplex ELISA. The density of Lactobacillus species and key bacterial vaginosis-associated bacterial taxa were determined by qPCR. Paired changes were assessed before and after cytobrush sampling. After 6 hours there were significant increases in CD4 + T cell, antigen presenting cell (APC) and neutrophil numbers; APC elevations persisted at 48 hours, while neutrophil and CD4 + T cell numbers returned to baseline. In addition, pro-inflammatory cytokine levels were increased at 6 hours and returned to baseline by 48 hours. No significant changes were observed in the absolute abundance of Lactobacillus species or BV-associated bacteria at either time point. Overall, cytobrush sampling altered genital immune parameters at 6 hours, but only APC number increases persisted at 48 hours. This should be considered in longitudinal analyses of FGT immunology.


Asunto(s)
Cuello del Útero/inmunología , Infecciones por VIH/epidemiología , VIH/aislamiento & purificación , Microbiota/inmunología , Manejo de Especímenes/métodos , Vagina/inmunología , Vaginosis Bacteriana/inmunología , Adolescente , Adulto , Canadá/epidemiología , Cuello del Útero/microbiología , Cuello del Útero/virología , Citocinas/análisis , Citocinas/inmunología , Femenino , Infecciones por VIH/diagnóstico , Infecciones por VIH/etiología , Humanos , Estudios Prospectivos , Vagina/microbiología , Vagina/virología , Vaginosis Bacteriana/microbiología , Vaginosis Bacteriana/virología , Carga Viral , Adulto Joven
15.
Am J Physiol Regul Integr Comp Physiol ; 297(4): R1009-18, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19641130

RESUMEN

Vasopressin type 2 receptor (V2R) exhibits mostly important properties for hydroosmotic equilibrium and, to a lesser extent, on vasomotricity. Drugs currently acting on this receptor are analogs of the natural neuropeptide, arginine vasopressin (AVP), and hence are competitive ligands. Peptides that reproduce specific sequences of a given receptor have lately been reported to interfere with its action, and if such molecules arise from regions remote from the binding site they would be anticipated to exhibit noncompetitive antagonism, but this has yet to be shown for V2R. Six peptides reproducing juxtamembranous regions of V2R were designed and screened; the most effective peptide, cravky (labeled VRQ397), was characterized. VRQ397 was potent (IC(50) = 0.69 +/- 0.25 nM) and fully effective in inhibiting V2R-dependent physiological function, specifically desmopressin-L-desamino-8-arginine-vasopressin (DDAVP)-induced cremasteric vasorelaxation; this physiological functional assay was utilized to avoid overlooking interference of specific signaling events. A dose-response profile revealed a noncompetitive property of VRQ397; correspondingly, VRQ397 bound specifically to V2R-expressing cells could not displace its natural ligand, AVP, but modulated AVP binding kinetics (dissociation rate). Specificity of VRQ397 was further confirmed by its inability to bind to homologous V1 and oxytocin receptors and its inefficacy to alter responses to stimulation of these receptors. VRQ397 exhibited pharmacological permissiveness on V2R-induced signals, as it inhibited DDAVP-induced PGI(2) generation but not that of cAMP or recruitment of beta-arrestin2. Consistent with in vitro and ex vivo effects as a V2R antagonist, VRQ397 displayed anticipated in vivo aquaretic efficacy. We hereby describe the discovery of a first potent noncompetitive antagonist of V2R, which exhibits functional selectivity, in line with properties of a negative allosteric modulator.


Asunto(s)
Antagonistas de los Receptores de Hormonas Antidiuréticas , Antagonistas de Hormonas/farmacología , Músculo Liso/efectos de los fármacos , Miometrio/efectos de los fármacos , Oligopéptidos/farmacología , Vejiga Urinaria/efectos de los fármacos , 6-Cetoprostaglandina F1 alfa/metabolismo , Regulación Alostérica , Animales , Arginina Vasopresina/metabolismo , Línea Celular , AMP Cíclico/metabolismo , Desamino Arginina Vasopresina/metabolismo , Diuresis/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Femenino , Antagonistas de Hormonas/metabolismo , Humanos , Técnicas In Vitro , Ligandos , Masculino , Ratones , Relajación Muscular/efectos de los fármacos , Músculo Liso/metabolismo , Miometrio/metabolismo , Oligopéptidos/metabolismo , Ratas , Ratas Sprague-Dawley , Receptores de Vasopresinas/genética , Receptores de Vasopresinas/metabolismo , Proteínas Recombinantes de Fusión/metabolismo , Transducción de Señal/efectos de los fármacos , Transfección , Vejiga Urinaria/metabolismo
16.
Science ; 294(5550): 2317-23, 2001 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-11743193

RESUMEN

The 5.67-megabase genome of the plant pathogen Agrobacterium tumefaciens C58 consists of a circular chromosome, a linear chromosome, and two plasmids. Extensive orthology and nucleotide colinearity between the genomes of A. tumefaciens and the plant symbiont Sinorhizobium meliloti suggest a recent evolutionary divergence. Their similarities include metabolic, transport, and regulatory systems that promote survival in the highly competitive rhizosphere; differences are apparent in their genome structure and virulence gene complement. Availability of the A. tumefaciens sequence will facilitate investigations into the molecular basis of pathogenesis and the evolutionary divergence of pathogenic and symbiotic lifestyles.


Asunto(s)
Agrobacterium tumefaciens/genética , Genoma Bacteriano , Análisis de Secuencia de ADN , Agrobacterium tumefaciens/clasificación , Agrobacterium tumefaciens/patogenicidad , Agrobacterium tumefaciens/fisiología , Adhesión Bacteriana/genética , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Proteínas Portadoras/genética , Proteínas Portadoras/metabolismo , Cromosomas Bacterianos/genética , Conjugación Genética , Replicación del ADN , Genes Bacterianos , Genes Reguladores , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Datos de Secuencia Molecular , Filogenia , Plantas/microbiología , Plásmidos , Replicón , Rhizobiaceae/genética , Rhizobiaceae/fisiología , Sinorhizobium meliloti/genética , Sinorhizobium meliloti/fisiología , Simbiosis , Virulencia/genética
17.
J Reprod Immunol ; 77(1): 32-40, 2008 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17395270

RESUMEN

HIV is generally sexually acquired across the genital or rectal mucosa after exposure to the genital secretions of an HIV-infected partner. Most exposures to HIV do not result in infection, likely due to protection afforded by an intact mucosal epithelium, as well as by innate and adaptive mucosal immune factors present in the genital tract. Another important mucosal determinant of transmission may be the number and activation status of potential HIV target cells, including CCR5/CD4+ T cells and DC-SIGN+ dendritic cells. The simultaneous presence of other genital infections, including classical sexually transmitted infections (STIs), can enhance HIV susceptibility either by breaching the epithelial barrier, recruiting HIV target cells to the genital tract, or by generating a pro-inflammatory local immune milieu. In HIV-infected individuals, genital co-infections increase HIV levels in the genital secretions, thereby increasing secondary sexual transmission. Co-infections that act as important HIV cofactors include human cytomegalovirus (CMV), Herpes simplex virus type 2 (HSV2), Neisseria gonorrhoeae and many others. Strategies focused on genital co-infections, such as vaccines, microbicides and suppressive therapy, are feasible in the short term and have the potential to curb the pandemic.


Asunto(s)
Genitales/inmunología , Infecciones por VIH/inmunología , Enfermedades de Transmisión Sexual/inmunología , Fármacos Anti-VIH/uso terapéutico , Infecciones por Citomegalovirus/inmunología , Infecciones por Citomegalovirus/transmisión , Susceptibilidad a Enfermedades , Femenino , Genitales/virología , Gonorrea/inmunología , Gonorrea/transmisión , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/transmisión , Herpes Genital/inmunología , Herpes Genital/transmisión , Humanos , Inmunidad Mucosa , Masculino , Carga Viral , Esparcimiento de Virus
18.
Indian J Med Res ; 127(4): 366-9, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18577791

RESUMEN

BACKGROUND & OBJECTIVE: Iron deficiency anaemia (IDA) is uncommon in individuals with sickle cell disease (SCD) because of availability of an adequate iron source potentially from increased red cell turnover and from blood transfusions. Also, iron deficiency anaemia can often go unnoticed because the sickle cell disease patients are already anaemic. Iron deficiency in sickle cell patients may result in lowering the intracellular haemoglobin concentration and this may ameliorate sickling. The present study was undertaken to determine the prevalence of iron deficiency anaemia and the response of iron supplementation in sickle cell disorders in tribal population of the four States viz. Maharashtra, Gujarat, Orissa and Tamil Nadu. METHODS: A total of 8434 individuals (7105 AA, 1267 AS and 62 SS) were tested for zinc protoporphyrin/haem (ZPP/H) ratio and haemoglobin levels. Twenty two sickle cell anaemia (SS), 47 sickle cell trait (AS) and 150 normal control (AA) individuals who were iron deficient, were given iron therapy for a period of 12 wk and the laboratory investigations were repeated at the 13th wk. RESULTS: Sixty seven per cent of subjects with sickle cell anaemia and 26 per cent with sickle cell trait had elevated ZPP/H ratios (>80 micromol/mol) as against 22.8 per cent of normal individuals. The elevated ZPP/H ratios is an indicator of microcytic anaemia of iron deficiency. Following iron therapy, an improvement in the Hb levels and ZPP/H ratios was observed in both sickle cell disorders and normal individual cases. INTERPRETATION & CONCLUSION: This study suggests that iron deficiency anaemia is an important problem in Indian sickle cell anaemia patients and iron supplementation should be given only in proven cases of iron deficiency anaemia.


Asunto(s)
Anemia Ferropénica/tratamiento farmacológico , Anemia Ferropénica/epidemiología , Anemia de Células Falciformes/tratamiento farmacológico , Anemia de Células Falciformes/epidemiología , Hierro/uso terapéutico , Adolescente , Adulto , Anemia Ferropénica/sangre , Anemia de Células Falciformes/sangre , Niño , Femenino , Hemo/metabolismo , Humanos , India/epidemiología , Deficiencias de Hierro , Masculino , Prevalencia , Protoporfirinas/sangre
19.
South Asian J Cancer ; 7(2): 132-136, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29721480

RESUMEN

Axillary lymph node involvement is a very important poor prognostic factor in the clinical staging and management of breast cancer patients. Traditionally, axillary lymph node dissection (ALND) has been used for determining the status of the axillary lymph nodes. More recently the sentinel lymph node biopsy (SLNB) procedure has gained wider acceptance as the standard of care, having the advantage of being less invasivewhile providing good accuracy. This expert group used data from published literature, practical experience and opinion of a large group of academic oncologists to arrive at these practical consensus recommendations in regards with the use of the two different procedures and other issues in patients with early breast cancer for the benefit of community oncologists.

20.
J Clin Invest ; 107(10): 1303-10, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11375420

RESUMEN

HIV-1-specific cytotoxic T-lymphocyte (CTL) responses have been detected at a low frequency in many HIV-1-exposed, persistently seronegative (HEPS) subjects. However, it is unclear how CTLs could protect against HIV acquisition in HEPS subjects, when high levels of circulating CTL fail to prevent disease progression in most seropositive subjects. To address this issue we studied CD8(+) lymphocyte responses to a panel of HIV-1 CTL epitopes in 91 HEPS and 87 HIV-1-infected Nairobi sex workers. HIV-specific responses in seropositive women focused strongly on epitopes rarely or never recognized in HEPS subjects, who targeted epitopes that were subdominant or unrecognized in infected women. These differences in epitope specificity were restricted by only those HLA class I alleles that are associated with a reduced risk of HIV-1 infection in this cohort. Late seroconversion in HEPS donors was associated with a switch in epitope specificity and/or immunodominance to those epitopes preferentially recognized by HIV-1-infected women. The likelihood of detecting HIV-1-specific responses in HEPS women increased with the duration of viral exposure, suggesting that HIV-1-specific CD8(+) responses are acquired over time. The association between differential recognition of distinct CTL epitopes and protection from HIV-1 infection may have significant implications for vaccine design.


Asunto(s)
Linfocitos T CD8-positivos/inmunología , Epítopos/inmunología , Infecciones por VIH/inmunología , Seronegatividad para VIH/inmunología , VIH-1/inmunología , Estudios de Cohortes , Femenino , Genes MHC Clase I , Seropositividad para VIH , Antígenos de Histocompatibilidad Clase I , Humanos , Epítopos Inmunodominantes , Kenia , Oligopéptidos/inmunología , Factores de Riesgo , Trabajo Sexual , Linfocitos T Citotóxicos/inmunología
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