Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 36
Filtrar
1.
Cureus ; 14(7): e27197, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36039200

RESUMO

BACKGROUND: Carbapenemase-producing Klebsiella pneumoniae (CRKP) has become a menace in several intensive care units, which needs to be controlled immediately after being reported by a laboratory. Detection in the laboratory is usually done using phenotypic methods and it is not known whether knowledge of these genes helps in individual patient management. This study aimed to compare the outcomes of oxacillinases ß-lactamases (OXA-48) and New Delhi metallo-ß-lactamase (NDM-1)-producing CRKP isolates, the two most common carbapenemases reported from India, obtained from patients with bloodstream infections in an ICU in a tertiary care center in North India and to compare the different laboratory methods for their detection. MATERIALS AND METHODS: Klebsiella pneumoniae isolates obtained from the blood culture of patients admitted to various ICUs were subjected to conventional polymerase chain reaction (PCRs) for blaNDM and blaOXA48-like genes. Those positive for any of the genes were tested by the modified carbapenem inactivation method (mCIM) and if found positive were also subjected to ethylenediamine tetraacetic acid (EDTA)-modified carbapenem inactivation method (eCIM). Antibiotic susceptibility tests (AST) were performed and clinical data were recorded. RESULTS: A total of 49 isolates were positive for one or more carbapenemase genes (30 {61.2%} for blaNDM gene only, 13 {26.5%)} for blaOXA48-like gene only, and six {12.2%} for both). The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of mCIM were found to be 77.6%, 100%, 100%, and 78.9%, respectively. Statistically significant differences were found in the AST pattern between the isolates with two genes. Increased MIC levels of colistin were observed, though they lay in the sensitive range. Mortality occurred in all six patients who were infected with CRKP harboring both the genes though no significant difference was observed in NDM and OXA-48 producing CRKP isolates. CONCLUSION: Surveillance of carbapenemase genes in a hospital setting is essential. The possible reasons for the low diagnostic accuracy of mCIM and differences in AST patterns are discussed.

2.
PLoS One ; 16(9): e0256308, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34495985

RESUMO

INTRODUCTION: Ventilator-associated pneumonia (VAP) may be a life threatening nosocomial infection encountered in intensive care units. Currently the emergence of carbapenem-resistant Gram-negative pathogens has become worrisome threat worldwide. MATERIAL AND METHODS: Endotracheal aspirates samples were collected from patients who were under mechanical ventilation for > 48 h. The bacterial isolates were identified by MALDI-TOF-MS and antibiotic susceptibility testing performed. All carbapenem resistant isolates were tested by Modified Hodge test (MHT), modified carbapenem inactivation method (mCIM), and EDTA-CIM (eCIM) and PCR were performed to detect blaIMP, blaVIM and blaNDM producing MBL genes. RESULTS: VAP occurred in 172/353(48.7%), 23.3% had early-onset VAP and 76.7% had late-onset VAP. Males (69.2%) were found to suffer more from VAP. Prior antibiotic therapy, CPI>6, prior surgery and tracheostomy were associated with VAP. The mortality in VAP (58.1%) contrasted with non-VAP (40%). 99/169 (58.6%) Gram-negative isolates were resistant to carbapenems. Acinetobacter baumannii, Pseudomonas aeruginosa and Klebsiella pneumoniae were common pathogens found in late onset VAP, whereas K. pneumoniae, A. baumannii and Staphylococcus aureus were common in early onset VAP. The PCR results detected blaNDM in 37/172(21.5%) and blaVIM in 30/172(17.4%); 15/172(8.7%) isolates carried both genes. CONCLUSION: The blaNDM-1 and blaVIM genes are the main antibiotic-resistance genes that induce resistance patterns to carbapenems in VAP, highlighting CRE strains of potential public health concern and therapeutic challenge. Diagnostic laboratories in India must get on high caution for early MBL detection as it may limit the wide dispersal of MBL genes.


Assuntos
Carbapenêmicos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Infecções por Bactérias Gram-Negativas/complicações , Testes de Sensibilidade Microbiana/métodos , Pneumonia Associada à Ventilação Mecânica/epidemiologia , beta-Lactamases/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Serviços de Laboratório Clínico , Farmacorresistência Bacteriana , Feminino , Bactérias Gram-Negativas/isolamento & purificação , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , Infecções por Bactérias Gram-Negativas/microbiologia , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Pneumonia Associada à Ventilação Mecânica/tratamento farmacológico , Pneumonia Associada à Ventilação Mecânica/microbiologia , Adulto Jovem
3.
Genome Med ; 10(1): 60, 2018 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-30053901

RESUMO

BACKGROUND: Although large-scale, next-generation sequencing (NGS) studies of cancers hold promise for enabling precision oncology, challenges remain in integrating NGS with clinically validated biomarkers. METHODS: To overcome such challenges, we utilized the Database of Evidence for Precision Oncology (DEPO) to link druggability to genomic, transcriptomic, and proteomic biomarkers. Using a pan-cancer cohort of 6570 tumors, we identified tumors with potentially druggable biomarkers consisting of drug-associated mutations, mRNA expression outliers, and protein/phosphoprotein expression outliers identified by DEPO. RESULTS: Within the pan-cancer cohort of 6570 tumors, we found that 3% are druggable based on FDA-approved drug-mutation interactions in specific cancer types. However, mRNA/phosphoprotein/protein expression outliers and drug repurposing across cancer types suggest potential druggability in up to 16% of tumors. The percentage of potential drug-associated tumors can increase to 48% if we consider preclinical evidence. Further, our analyses showed co-occurring potentially druggable multi-omics alterations in 32% of tumors, indicating a role for individualized combinational therapy, with evidence supporting mTOR/PI3K/ESR1 co-inhibition and BRAF/AKT co-inhibition in 1.6 and 0.8% of tumors, respectively. We experimentally validated a subset of putative druggable mutations in BRAF identified by a protein structure-based computational tool. Finally, analysis of a large-scale drug screening dataset lent further evidence supporting repurposing of drugs across cancer types and the use of expression outliers for inferring druggability. CONCLUSIONS: Our results suggest that an integrated analysis platform can nominate multi-omics alterations as biomarkers of druggability and aid ongoing efforts to bring precision oncology to patients.


Assuntos
Biomarcadores Tumorais/genética , Genômica/métodos , Terapia de Alvo Molecular/métodos , Neoplasias/genética , Variantes Farmacogenômicos , Medicina de Precisão/métodos , Feminino , Células HEK293 , Humanos , Masculino , Mutação , Neoplasias/tratamento farmacológico , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo
4.
PLoS Negl Trop Dis ; 12(3): e0006346, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29590177

RESUMO

BACKGROUND: Acute Encephalitis Syndrome (AES) is a major seasonal public health problem in Bihar, India. Despite efforts of the Bihar health department and the Government of India, burden and mortality of AES cases have not decreased, and definitive etiologies for the illness have yet to be identified. OBJECTIVES: The present study was undertaken to study the specific etiology of AES in Bihar. METHODS: Cerebrospinal fluid and/or serum samples from AES patients were collected and tested for various pathogens, including viruses and bacteria by ELISA and/or Real Time PCR. FINDINGS: Of 540 enrolled patients, 33.3% (180) tested positive for at least one pathogen of which 23.3% were co-positive for more than one pathogen. Most samples were positive for scrub typhus IgM or PCR (25%), followed by IgM positivity for JEV (8.1%), WNV (6.8%), DV (6.1%), and ChikV (4.5%).M. tuberculosis and S. pneumoniae each was detected in ~ 1% cases. H. influenzae, adenovirus, Herpes Simplex Virus -1, enterovirus, and measles virus, each was detected occasionally. The presence of Scrub typhus was confirmed by PCR and sequencing. Bihar strains resembled Gilliam-like strains from Thailand, Combodia and Vietnam. CONCLUSION: The highlights of this pilot AES study were detection of an infectious etiology in one third of the AES cases, multiple etiologies, and emergence of O. tsutsugamushi infection as an important causative agent of AES in India.


Assuntos
Encefalopatia Aguda Febril/epidemiologia , Encefalopatia Aguda Febril/etiologia , Orientia tsutsugamushi/isolamento & purificação , Tifo por Ácaros/complicações , Encefalopatia Aguda Febril/sangue , Encefalopatia Aguda Febril/líquido cefalorraquidiano , Adolescente , Adulto , Idoso , Anticorpos Antibacterianos/sangue , Anticorpos Antibacterianos/líquido cefalorraquidiano , Criança , Pré-Escolar , Efeitos Psicossociais da Doença , Ensaio de Imunoadsorção Enzimática , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Imunoglobulina M/sangue , Imunoglobulina M/líquido cefalorraquidiano , Índia/epidemiologia , Lactente , Masculino , Pessoa de Meia-Idade , Orientia tsutsugamushi/genética , Orientia tsutsugamushi/imunologia , Filogenia , Projetos Piloto , Reação em Cadeia da Polimerase , Tifo por Ácaros/microbiologia , Centros de Atenção Terciária , Adulto Jovem
5.
Indian J Otolaryngol Head Neck Surg ; 69(4): 459-463, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29238674

RESUMO

Both type of CSOM, tubotympanic which is considered safe as well as atticoantral which is considered unsafe may lead to erosion of the ossicular chain. Discontinuity of the ossicular chain is typically confirmed only during an operation. Knowing before surgery whether the patient has an ossicular discontinuity is important because it allows the surgeon to know the possibility of performing an ossiculoplasty and obtaining patient consent. The aims is to (1) study the incidence of incus necrosis in safe and unsafe CSOM. (2) Determine the preoperative predictive factors for incus necrosis. (3) Use angled otoscopes to determine the incidence of residual disease peroperative after conventional microscopic surgery. This is a prospective study carried out in the department of otorhinolaryngology, Govt Doon medical college, Dehradun from July 2014 to July 2016. A total of 100 patients who presented with CSOM and have not undergone any surgical procedure for the same were included in this study. Patients group was divided into cholesteatoma and non cholesteatoma group. Both groups were subdivided into intact and eroded incus group and were analysed in 11 parameters which were compared statistically. Incudal necrosis is more common in cholesteatoma group. In non cholesteatoma ears subtotal perforation with exposure of IS joint is reliable indicators of incudal necrosis. In non cholesteatoma group extension of cholesteatoma to tympanic sinus and mastoid and presence of persistent discharge are reliable indicators of necrosed incus. Moderate to moderately severe hearing loss indicate incudal necrosis in both groups therefore we conclude that these parameters can be reliably considered as predictors for incudal necrosis preoperatively.

7.
J Ayurveda Integr Med ; 7(3): 167-172, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27637447

RESUMO

BACKGROUND: The standards of Ayurveda education in India are being questioned in the recent years and many suggestions related to educational reforms are being put forth by educators and health policy experts. However, the Post Graduate Entrance Examinations (PGEEs) that are carried out to select the candidates to pursue postgraduate programs have received little attention in this context. OBJECTIVES: The objective of this study was to classify the Multiple Choice Questions (MCQs) from Ayurveda PGEEs conducted in different universities of India during the five year period (ranging from 2010 to 2014) into six levels of Bloom's Taxonomy in cognitive domain. METHODS: This is a retrospective observational study. The sampling method followed was purposive sampling. Totally, 3299 MCQs obtained out of 25 question papers from seven universities spread across four zones of India (North, South, West and East) were included in the study and were classified based on the Bloom's taxonomy. RESULTS: About 93.3% of MCQs assessed only the 'recall' component whereas 6.2% of the MCQs assessed 'comprehension'. Percentage of MCQs that assessed 'application' level was a mere 0.3% whereas the percentage of MCQs that assessed the 'analysis' component was found to be only 0.2%. There was not even a single question to assess the 'synthesis' and 'evaluation' components. CONCLUSIONS: We conclude that an appropriate proportion of MCQs assessing 'higher order thinking' are required to be included in Ayurveda PGEEs. While it is possible to frame MCQs to assess all six levels of Bloom's taxonomy in cognitive domain, the teachers are required to be trained well in the skills of MCQ writing. We propose that our study may be taken as a lead to introduce the required reforms in PGEEs. Clinical Trial Registration No.: Not applicable.

8.
Nat Genet ; 48(8): 827-37, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27294619

RESUMO

Local concentrations of mutations are well known in human cancers. However, their three-dimensional spatial relationships in the encoded protein have yet to be systematically explored. We developed a computational tool, HotSpot3D, to identify such spatial hotspots (clusters) and to interpret the potential function of variants within them. We applied HotSpot3D to >4,400 TCGA tumors across 19 cancer types, discovering >6,000 intra- and intermolecular clusters, some of which showed tumor and/or tissue specificity. In addition, we identified 369 rare mutations in genes including TP53, PTEN, VHL, EGFR, and FBXW7 and 99 medium-recurrence mutations in genes such as RUNX1, MTOR, CA3, PI3, and PTPN11, all mapping within clusters having potential functional implications. As a proof of concept, we validated our predictions in EGFR using high-throughput phosphorylation data and cell-line-based experimental evaluation. Finally, mutation-drug cluster and network analysis predicted over 800 promising candidates for druggable mutations, raising new possibilities for designing personalized treatments for patients carrying specific mutations.


Assuntos
Biologia Computacional/métodos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Mutação/genética , Proteínas de Neoplasias/química , Proteínas de Neoplasias/genética , Neoplasias/genética , Neoplasias/metabolismo , Algoritmos , Antineoplásicos/farmacologia , Bases de Dados de Produtos Farmacêuticos , Bases de Dados de Proteínas , Humanos , Modelos Moleculares , Proteínas de Neoplasias/metabolismo , Neoplasias/tratamento farmacológico , Ligação Proteica , Mapas de Interação de Proteínas , Estrutura Terciária de Proteína
9.
BMC Infect Dis ; 16: 67, 2016 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-26847071

RESUMO

BACKGROUND: Acute encephalitis syndrome (AES) is a public health problem in India. Neuroinfections are believed to be the most important etiology. Minocycline is a semisythetic tetracycline having excellent penetration into cerebrospinal fluid, established neuroprotective and antiviral properties besides action on nonviral causes of AES. It has been shown to be effective in animal model of Japanese encephalitis (JE). A randomized, controlled trial of nasogastric/oral minocycline in JE and AES at a single centre in Uttar Pradesh, northern India, was therefore conducted. METHODS: Patients beyond 3 years of age - but excluding women aged 16-44 years - hospitalized with AES of < =7 days duration were enrolled and block randomized to receive nasogastric/oral minocycline or placebo suspension and followed up. Patients, study personnel and those entering data were blinded as to drug or placebo received. Primary outcome was cumulative mortality at 3 months from hospitalization. Analysis was by intention to treat. RESULTS: 281 patients were enrolled, 140 received drug and 141 placebo. While there was no overall statistically significant difference in 3 month mortality between drug and placebo groups [RR = 0 · 83 (0 · 6-1 · 1)], there were encouraging trends in patients older than 12 years [RR = 0.70 (0.41-1.18)] and in Glasgow Outcome Score (GOS) at 3 months (χ(2) = 7 · 44, p = 0 · 059). These trends were further accentuated if patients dying within one day of reaching hospital were excluded [OR for 3 month mortality =0 · 70 (0 · 46-1 · 07), p = 0.090; 3 month GOS p = 0 · 028]. CONCLUSIONS: A trend towards better outcomes was observed with minocycline, especially in those patients who survived the initial day in hospital. These findings should form the basis for planning a larger study and possibly including minocycline in the initial management of AES as seen here. TRIAL REGISTRATION: The trial was registered with Clinical Trials Registry of India (CTRI) - CTRI/2010/091/006143.


Assuntos
Encefalite/tratamento farmacológico , Minociclina/administração & dosagem , Doença Aguda , Administração Oral , Adolescente , Criança , Pré-Escolar , Encefalite/epidemiologia , Encefalite Japonesa/tratamento farmacológico , Encefalite Japonesa/epidemiologia , Feminino , Mortalidade Hospitalar , Hospitais , Humanos , Índia/epidemiologia , Masculino , Síndrome
10.
Nat Commun ; 6: 10086, 2015 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-26689913

RESUMO

Large-scale cancer sequencing data enable discovery of rare germline cancer susceptibility variants. Here we systematically analyse 4,034 cases from The Cancer Genome Atlas cancer cases representing 12 cancer types. We find that the frequency of rare germline truncations in 114 cancer-susceptibility-associated genes varies widely, from 4% (acute myeloid leukaemia (AML)) to 19% (ovarian cancer), with a notably high frequency of 11% in stomach cancer. Burden testing identifies 13 cancer genes with significant enrichment of rare truncations, some associated with specific cancers (for example, RAD51C, PALB2 and MSH6 in AML, stomach and endometrial cancers, respectively). Significant, tumour-specific loss of heterozygosity occurs in nine genes (ATM, BAP1, BRCA1/2, BRIP1, FANCM, PALB2 and RAD51C/D). Moreover, our homology-directed repair assay of 68 BRCA1 rare missense variants supports the utility of allelic enrichment analysis for characterizing variants of unknown significance. The scale of this analysis and the somatic-germline integration enable the detection of rare variants that may affect individual susceptibility to tumour development, a critical step toward precision medicine.


Assuntos
Variação Genética , Neoplasias/genética , Neoplasias/metabolismo , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Neoplasias/classificação , Neoplasias/epidemiologia , Estados Unidos/epidemiologia , Adulto Jovem
11.
F1000Res ; 4: 334, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26309732

RESUMO

Japanese encephalitis (JE) is the leading cause of viral encephalitis in Asia. Acute encephalitis syndrome (AES) is a group of central nervous system (CNS) disorders caused by a wide range of viruses, bacteria, fungi, chemicals and toxins. It is important to distinguish between various forms of infectious encephalitis with similar clinical manifestations in order to ensure specific and accurate diagnosis and development of subsequent therapeutic strategies. Cerebrospinal fluid (CSF) is in direct contact with the CNS and hence it is considered to be an excellent source for identifying biomarkers for various neurological disorders. With the recent advancement in proteomic methodologies, the field of biomarker research has received a remarkable boost.  The present study identifies potential biomarkers for JE using a proteomics based approach. The CSF proteomes from ten patients each with JE and Non-JE acute encephalitis were analyzed by 2D gel electrophoresis followed by mass spectrometry. Vitamin D-binding protein (DBP), fibrinogen gamma chain, fibrinogen beta chain, complement C4-B, complement C3 and cytoplasmic actin were found to be significantly elevated in case of JE indicating severe disruption of the blood brain barrier and DBP can be suggested to be an important diagnostic marker.

12.
J Urol ; 193(5 Suppl): 1784-90, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25301096

RESUMO

PURPOSE: The calcineurin-NFAT signaling pathway regulates the transcription of genes important for development. It is impacted by various genetic and environmental factors. We investigated the potential role of NFAT induced transcriptional dysregulation in the pathogenesis of congenital abnormalities of the kidneys and urinary tract. MATERIALS AND METHODS: A murine model of conditional NFATc1 activation in the ureteric bud was generated and examined for histopathological changes. Metanephroi were also cultured in vitro to analyze branching morphogenesis in real time. RESULTS: NFATc1 activation led to defects resembling multicystic dysplastic kidney. These mutants showed severe disorganization of branching morphogenesis characterized by decreased ureteric bud branching and the disconnection of ureteric bud derivatives from the main collecting system. The orphan ureteric bud derivatives may have continued to induce nephrogenesis and likely contributed to the subsequent formation of blunt ended filtration units and cysts. The ureter also showed irregularities consistent with impaired epithelial-mesenchymal interaction. CONCLUSIONS: This study reveals the profound effects of NFAT signaling dysregulation on the ureteric bud and provides insight into the pathogenesis of multicystic dysplastic kidney. Our results suggest that the obstruction hypothesis and the bud theory may not be mutually exclusive to explain the pathogenesis of multicystic dysplastic kidney. Ureteric bud dysfunction such as that induced by NFAT activation can disrupt ureteric bud-metanephric mesenchyma interaction, causing primary defects in branching morphogenesis, subsequent dysplasia and cyst formation. Obstruction of the main collecting system can further enhance these defects, producing the pathological changes associated with multicystic dysplastic kidney.


Assuntos
Rim Displásico Multicístico/embriologia , Fatores de Transcrição NFATC/fisiologia , Organogênese/fisiologia , Ureter/embriologia , Animais , Calcineurina/fisiologia , Camundongos , Transdução de Sinais/fisiologia , Transcrição Gênica
13.
J Am Soc Nephrol ; 26(1): 149-59, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24904084

RESUMO

A disintegrin and metalloproteinase domain 10 (Adam10), a member of the ADAM family of cell membrane-anchored proteins, has been linked to the regulation of the Notch, EGF, E-cadherin, and other signaling pathways. However, it is unclear what role Adam10 has in the kidney in vivo. In this study, we showed that Adam10 deficiency in ureteric bud (UB) derivatives leads to a decrease in urinary concentrating ability, polyuria, and hydronephrosis in mice. Furthermore, Adam10 deficiency led to a reduction in the percentage of aquaporin 2 (Aqp2)(+) principal cells (PCs) in the collecting ducts that was accompanied by a proportional increase in the percentage of intercalated cells (ICs). This increase was more prominent in type A ICs than in type B ICs. Foxi1, a transcription factor important for the differentiation of ICs, was upregulated in the Adam10 mutants. The observed reduction of Notch activity in Adam10 mutant collecting duct epithelium and the similar reduction of PC/IC ratios in the collecting ducts in mice deficient for mindbomb E3 ubiquitin protein ligase 1, a key regulator of the Notch and Wnt/receptor-like tyrosine kinase signaling pathways, suggest that Adam10 regulates cell fate determination through the activation of Notch signaling, probably through the regulation of Foxi1 expression. However, phenotypic differences between the Adam10 mutants, the Mib1 mutants, and the Foxi1 mutants suggest that the functions of Adam10 in determining the fate of collecting duct cells are more complex than those of a simple upstream factor in a linear pathway involving Notch and Foxi1.


Assuntos
Proteínas ADAM/metabolismo , Secretases da Proteína Precursora do Amiloide/metabolismo , Rim/metabolismo , Proteínas de Membrana/metabolismo , Proteína ADAM10 , Animais , Apoptose , Aquaporina 2/metabolismo , Caderinas/metabolismo , Proliferação de Células , Células Epiteliais/citologia , Fatores de Transcrição Forkhead/metabolismo , Hidronefrose/genética , Túbulos Renais/citologia , Túbulos Renais Coletores/metabolismo , Ligantes , Camundongos , Camundongos Transgênicos , Mutação , Poliúria/genética , Receptores Notch/metabolismo , Transdução de Sinais , Células-Tronco/citologia , Regulação para Cima , Via de Sinalização Wnt
14.
Proc Natl Acad Sci U S A ; 111(36): E3766-74, 2014 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-25157135

RESUMO

The paracellular pathway through the tight junction provides an important route for transepithelial chloride reabsorption in the kidney, which regulates extracellular salt content and blood pressure. Defects in paracellular chloride reabsorption may in theory cause deregulation of blood pressure. However, there is no evidence to prove this theory or to demonstrate the in vivo role of the paracellular pathway in renal chloride handling. Here, using a tissue-specific KO approach, we have revealed a chloride transport pathway in the kidney that requires the tight junction molecule claudin-4. The collecting duct-specific claudin-4 KO animals developed hypotension, hypochloremia, and metabolic alkalosis due to profound renal wasting of chloride. The claudin-4-mediated chloride conductance can be regulated endogenously by a protease-channel-activating protease 1 (cap1). Mechanistically, cap1 regulates claudin-4 intercellular interaction and membrane stability. A putative cap1 cleavage site has been identified in the second extracellular loop of claudin-4, mutation of which abolished its regulation by cap1. The cap1 effects on paracellular chloride permeation can be extended to other proteases such as trypsin, suggesting a general mechanism may also exist for proteases to regulate the tight junction permeabilities. Together, we have discovered a theory that paracellular chloride permeability is physiologically regulated and essential to renal salt homeostasis and blood pressure control.


Assuntos
Pressão Sanguínea , Cloretos/metabolismo , Claudina-4/metabolismo , Rim/metabolismo , Reabsorção Renal , Serina Endopeptidases/metabolismo , Animais , Pressão Sanguínea/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Permeabilidade da Membrana Celular/efeitos dos fármacos , Eletrólitos/sangue , Eletrólitos/urina , Células HEK293 , Humanos , Rim/efeitos dos fármacos , Túbulos Renais Coletores/efeitos dos fármacos , Túbulos Renais Coletores/metabolismo , Camundongos Knockout , Especificidade de Órgãos/efeitos dos fármacos , Ligação Proteica/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Interferência de RNA/efeitos dos fármacos , Proteínas Recombinantes/farmacologia , Reabsorção Renal/efeitos dos fármacos , Telemetria , Tripsina/metabolismo
16.
J Am Soc Nephrol ; 23(4): 618-28, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22282597

RESUMO

Obstruction of the ureteropelvic junction (UPJ) is a common congenital anomaly frequently associated with ureteral defects. To study the molecular mechanisms that modulate ureteral development, we inactivated Smad4, the common Smad critical for transcriptional responses to TGF-ß and Bmp signaling, in the ureteral and bladder mesenchyme during embryogenesis. Loss of canonical Smad signaling in these tissues caused bilateral UPJ obstruction and severe hydronephrosis beginning at embryonic day 17.5. Despite a reduction in quantity of ureteral smooth muscle, differentiation proceeded without Smad4, producing a less severe phenotype than Bmp4 mutants; this finding suggests that at least some Bmp4 functions in ureteral smooth muscle may be Smad-independent. The absence of canonical Smad signaling in the ureteral mesenchyme, but not in the urothelium itself, led to urothelial disorganization, highlighting the importance of mesenchymal support for epithelial development. Transcript profiling revealed altered expression in known Bmp targets, smooth muscle-specific genes, and extracellular matrix-related genes in mutant ureters before the onset of hydronephrosis. Expression of the Bmp target Id2 was significantly lower in Smad4 mutants, consistent with the observation that Id2 mutants develop UPJ obstruction. In summary, Smad4 deficiency reduces the number and contractility of ureteral smooth muscle cells, leading to abnormal pyeloureteral peristalsis and functional obstruction. The subsequent bending and luminal constriction of the ureter at the UPJ marks the transition from a functional obstruction to a more intractable physical obstruction, suggesting that early intervention for this disease may prevent more irreversible damage to the urinary tract.


Assuntos
Pelve Renal/embriologia , Proteína Smad4/genética , Ureter/embriologia , Obstrução Ureteral/genética , Bexiga Urinária/embriologia , Animais , Células Cultivadas , Modelos Animais de Doenças , Regulação da Expressão Gênica no Desenvolvimento , Mesoderma/metabolismo , Camundongos , Camundongos Transgênicos , Miócitos de Músculo Liso , Reação em Cadeia da Polimerase , Análise Serial de Proteínas , Distribuição Aleatória , Sensibilidade e Especificidade , Transdução de Sinais , Proteína Smad4/metabolismo , Ureter/metabolismo , Bexiga Urinária/metabolismo
17.
Organogenesis ; 7(3): 154-62, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21654197

RESUMO

Transplantation therapy for human diabetes is limited by the toxicity of immunosuppressive drugs. If toxicity can be minimized, there will still be a shortage of human donor organs. Xenotransplantation of porcine islets is a strategy to overcome supply problems. Xenotransplantation in mesentery of pig pancreatic primordia obtained very early during organogenesis [embryonic day 28 (E28)] is a way to obviate the need for immunosuppression in rats or rhesus macaques and to enable engraftment of a cell component originating from porcine islets implanted beneath the renal capsule of rats. Here, we show engraftment in the kidney of insulin and porcine proinsulin mRNA-expressing cells following implantation of porcine islets beneath the renal capsule of diabetic rhesus macaques transplanted previously with E28 pig pancreatic primordia in mesentery. Donor cell engraftment is confirmed using fluorescent in situ hybridization (FISH) for the porcine X chromosome and is supported by glucose-stimulated insulin release in vitro. Cells from islets do not engraft in the kidney without prior transplantation of E28 pig pancreatic primordia in mesentery. This is the first report of engraftment following transplantation of porcine islets in non-immunosuppressed, immune-competent non-human primates. The data are consistent with tolerance to a cell component of porcine islets induced by previous transplantation of E28 pig pancreatic primordia.


Assuntos
Diabetes Mellitus Experimental/patologia , Transplante das Ilhotas Pancreáticas , Animais , Diabetes Mellitus Experimental/imunologia , Diabetes Mellitus Experimental/terapia , Embrião de Mamíferos , Sobrevivência de Enxerto , Terapia de Imunossupressão , Insulina/genética , Insulina/metabolismo , Secreção de Insulina , Ilhotas Pancreáticas/patologia , Transplante das Ilhotas Pancreáticas/imunologia , Rim/patologia , Macaca mulatta , Mesentério/cirurgia , Transplante de Pâncreas , Proinsulina/genética , Proinsulina/metabolismo , RNA Mensageiro/metabolismo , Suínos , Transplante Heterólogo/imunologia
18.
J Urol ; 185(6): 2320-8, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21511282

RESUMO

PURPOSE: We genetically disrupted the wolffian duct in mice to study the affected organogenesis processes and to test the hypothesis that cell loss can be the developmental basis for a wide spectrum of congenital anomalies in the kidney and urinary tract. MATERIALS AND METHODS: We used Hoxb7-Cre transgenic lines (HC1 and HC2) to induce diphtheria toxin production from a ROSA(DTA) allele, disrupting the wolffian duct and derivatives. RESULTS: The first set of mutants (HC1;ROSA(DTA/+)) exhibited agenesis of the kidney, ureter and reproductive tracts. The second set of mutants (HC2;ROSA(DTA/+)) exhibited diverse defects, including renal agenesis/hypoplasia, hydronephrosis, hydroureter, ureter-vas deferens fistulas in males and ureter-oviduct/uterus fistulas in females. The phenotypic differences correspond to the degree of apoptosis induced caudal truncation of the wolffian duct, which is less severe and more variable in HC2;ROSA(DTA/+) mice. Whenever the wolffian duct failed to reach the urogenital sinus, the ureter failed to separate from the wolffian duct, suggesting that ureteral migration along the common nephric duct to the cloaca and the subsequent common nephric duct degeneration constitute the only pathway for separating the ureter and wolffian duct derivatives. CONCLUSIONS: The diverse and severe defects observed emphasize the central role of the wolffian duct in providing progenitors and signals for urogenital development. These results also indicate that the quantitative difference in cell death induced caudal truncation of the wolffian duct can lead to a wide range of qualitatively distinct defects, and that cell death can serve as a single etiological cause of a wide spectrum of congenital kidney and urinary tract defects.


Assuntos
Sistema Urinário/anormalidades , Animais , Apoptose/genética , Morte Celular/genética , Feminino , Rim/anormalidades , Masculino , Camundongos , Ductos Mesonéfricos/anormalidades
20.
Artigo em Inglês | MEDLINE | ID: mdl-20953421

RESUMO

According to Ayurveda, the native Indian system of healthcare, three Doshas, namely, Vata, Pitta, and Kapha, are the basic mutually reciprocal mechanisms that are responsible for the maintenance of homeostasis in human beings. Ayurveda classifies entire human population into seven constitutional types (Prakriti), based on the dominance of any single or a combination of two or three Doshas. Considering the fact that, in the recent past there have been several studies that have proposed some important genetic, biochemical and haematological bases for Prakriti, we conducted the present study in 90 randomly selected clinically healthy volunteers belonging to dual constitutional types (Dvandvaja Prakriti) to evaluate the variability of heart rate and arterial blood pressure in response to specific postural changes, exercise, and cold pressor test. The results of this study, in general, suggest that these basic cardiovascular responses do not vary significantly as per the dual constitutional types. However, we noted a significant fall in the diastolic blood pressure immediately after performing the isotonic exercise for five minutes, in Vata-Kapha individuals in comparison to the other two groups, namely, Pitta-Kapha and Vata-Pitta.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...