Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
BMJ Case Rep ; 14(7)2021 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-34257129

RESUMO

We report clinical findings of three patients presenting with thrombosis and thrombocytopaenia 10-16 days following the first dose of the ChAdOx1 nCoV-19 vaccine against SARS-CoV-2. All patients presented to a major university teaching hospital in the UK over a 5-day period and were found to have high-titre antibodies against platelet factor 4 (PF4) without previous exposure to heparin. All three patients presented with extensive venous thrombosis, significant thrombocytopaenia, elevated D-dimer and borderline low fibrinogen. Two had fatal intracerebral haemorrhage secondary to cavernous venous sinus thrombosis and one had PE. Reference laboratory testing of serum demonstrated anti-PF4 antibodies in all three patients. The clinical and laboratory findings confirmed vaccine-induced thrombotic thrombocytopaenia (VITT) which was poorly described at the time of presentation. We were able to manage successfully one patient with PE with intravenous immunoglobulin and corticosteroids.


Assuntos
COVID-19 , Trombocitopenia , Trombose , Vacinas contra COVID-19 , ChAdOx1 nCoV-19 , Humanos , SARS-CoV-2 , Trombocitopenia/induzido quimicamente , Trombose/etiologia , Reino Unido , Vacinação/efeitos adversos
2.
BMJ Case Rep ; 14(6)2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34083189

RESUMO

A 7-year-old boy with Marfanoid habitus presented with sudden and painless decrease in the vision of the right eye. Ocular examination revealed rhegmatogenous retinal detachment with 360° giant retinal tear in the right eye and small peripheral retinal breaks with lattice degeneration in the left eye. The patient underwent a 23-gauge pars plana vitrectomy with scleral buckling in the right eye and laser around the breaks in the left eye. At 1-week follow-up visit, the child presented with similar complaints in the left eye as were seen in the right eye. This was later managed effectively with 23-gauge pars plana vitrectomy only. So, with our case report, we would like to highlight the need for aggressive screening in children who are diagnosed with Marfan's syndrome and the need for prophylactic treatment in the unaffected eye.


Assuntos
Síndrome de Marfan , Descolamento Retiniano , Perfurações Retinianas , Criança , Humanos , Masculino , Síndrome de Marfan/complicações , Descolamento Retiniano/etiologia , Descolamento Retiniano/cirurgia , Perfurações Retinianas/diagnóstico , Perfurações Retinianas/etiologia , Perfurações Retinianas/cirurgia , Estudos Retrospectivos , Recurvamento da Esclera , Resultado do Tratamento , Acuidade Visual , Vitrectomia
5.
Inhal Toxicol ; 30(3): 133-139, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29793367

RESUMO

OBJECTIVE: Workers exposed to dusts from concentrated animal feeding operations have a high prevalence of pulmonary diseases. These exposures lead to chronic inflammation and aberrant airway remodeling. Previous work shows that activating cAMP-dependent protein kinase (PKA) enhances airway epithelial wound repair while activating protein kinase C (PKC) inhibits wound repair. Hog barn dust extracts slow cell migration and wound repair via a PKC-dependent mechanism. Further, blocking nitric oxide (NO) production in bronchial epithelial cells prevents PKA activation. We hypothesized that blocking an endogenous NO inhibitor, asymmetric dimethylarginine, by overexpressing dimethylarginine dimethylaminohydrolase mitigates the effects of hog dust extract on airway epithelial would repair. MATERIALS/METHODS: We cultured primary tracheal epithelial cells in monolayers from both wild-type (WT) and dimethylarginine dimethylaminohydrolase overexpressing C57Bl/6 (DDAH1 transgenic) mice and measured wound repair using the electric cell impedance sensing system. RESULTS: Wound closure in epithelial cells from WT mice occurred within 24 h in vitro. In contrast, treatment of the WT cell monolayers with 5% hog dust extract prevented significant NO-stimulated wound closure. In cells from DDAH1 transgenic mice, control wounds were repaired up to 8 h earlier than seen in WT mice. A significant enhancement of wound repair was observed in DDAH cells compared to WT cells treated with hog dust extract for 24 h. Likewise, cells from DDAH1 transgenic mice demonstrated increased NO and PKA activity and decreased hog dust extract-stimulated PKC. DISCUSSION/CONCLUSION: Preserving the NO signal through endogenous inhibition of asymmetric dimethylarginine enhances wound repair even in the presence of dust exposure.


Assuntos
Amidoidrolases/genética , Criação de Animais Domésticos , Poeira , Células Epiteliais/fisiologia , Cicatrização , Animais , Arginina/análogos & derivados , Arginina/metabolismo , Células Cultivadas , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Óxido Nítrico/metabolismo , Proteína Quinase C/metabolismo , Traqueia/citologia
6.
Plant Cell Physiol ; 59(2): 262-274, 2018 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-29165715

RESUMO

Withanolides are a collection of naturally occurring, pharmacologically active, secondary metabolites synthesized in the medicinally important plant, Withania somnifera. These bioactive molecules are C28-steroidal lactone triterpenoids and their synthesis is proposed to take place via the mevalonate (MVA) and 2-C-methyl-d-erythritol-4-phosphate (MEP) pathways through the sterol pathway using 24-methylene cholesterol as substrate flux. Although the phytochemical profiles as well as pharmaceutical activities of Withania extracts have been well studied, limited genomic information and difficult genetic transformation have been a major bottleneck towards understanding the participation of specific genes in withanolide biosynthesis. In this study, we used the Tobacco rattle virus (TRV)-mediated virus-induced gene silencing (VIGS) approach to study the participation of key genes from MVA, MEP and triterpenoid biosynthesis for their involvement in withanolide biosynthesis. TRV-infected W. somnifera plants displayed unique phenotypic characteristics and differential accumulation of total Chl as well as carotenoid content for each silenced gene suggesting a reduction in overall isoprenoid synthesis. Comprehensive expression analysis of putative genes of withanolide biosynthesis revealed transcriptional modulations conferring the presence of complex regulatory mechanisms leading to withanolide biosynthesis. In addition, silencing of genes exhibited modulated total and specific withanolide accumulation at different levels as compared with control plants. Comparative analysis also suggests a major role for the MVA pathway as compared with the MEP pathway in providing substrate flux for withanolide biosynthesis. These results demonstrate that transcriptional regulation of selected Withania genes of the triterpenoid biosynthetic pathway critically affects withanolide biosynthesis, providing new horizons to explore this process further, in planta.


Assuntos
Vias Biossintéticas/genética , Inativação Gênica , Genes de Plantas , Vírus de Plantas/fisiologia , Plantas Medicinais/genética , Withania/genética , Vitanolídeos/metabolismo , Carotenoides/metabolismo , Clorofila/metabolismo , Regulação para Baixo/genética , Eritritol/análogos & derivados , Eritritol/metabolismo , Regulação da Expressão Gênica de Plantas , Ácido Mevalônico/metabolismo , Fenótipo , Folhas de Planta/genética , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/anatomia & histologia , Plantas Geneticamente Modificadas , Plantas Medicinais/anatomia & histologia , Plantas Medicinais/crescimento & desenvolvimento , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fosfatos Açúcares/metabolismo , Withania/anatomia & histologia , Withania/crescimento & desenvolvimento
7.
Infect Disord Drug Targets ; 18(2): 145-155, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-28595543

RESUMO

BACKGROUND: The unsatisfactory treatment options for Visceral Leishmaniasis (VL), need identification of new drug targets. Among natural products, Alkaloids have been proved to be highly effective against number of diseases. In Leishmania, UDP-galactopyranosemutase (UGM) is a critical enzyme required for cell wall synthesis and thus a drug target for structure based drug designing against L. donovani. OBJECTIVE: The aim was to build the homology model of UDP galactopyransemutase and investigate the interaction of selected alkaloids with this modeled UDP galactopyranosemutase by molecular docking. METHODOLOGY: Since no crystal structure record has been found with this protein, a homology modeling was performed and a three dimensional structure of L. donovani UGM was created using MODELLER v9.9, structure quality was validated using PROCHECK and QMEAN programs which confirms that the structure is reliable. Further Molecular docking was performed with previously reported15 alkaloids. RESULTS: It was found that Protopine with a binding energy of -12.39Kcal/mole, binds at Flavin adenine dinucleotide (FAD) biding site. CONCLUSION: It was concluded that Protopine, an alkaloid could interrupt the functional aspect of L. donovani UGM and thus may be useful for drug designing studies. These finding would contribute to the understanding of the effect of drug on the parasite.


Assuntos
Antiprotozoários/química , Benzofenantridinas/química , Alcaloides de Berberina/química , Transferases Intramoleculares/química , Leishmania donovani/enzimologia , Leishmaniose Visceral/parasitologia , Sequência de Aminoácidos , Sítios de Ligação , Desenho de Fármacos , Flavina-Adenina Dinucleotídeo/química , Humanos , Transferases Intramoleculares/genética , Conformação Molecular , Simulação de Acoplamento Molecular
8.
Sci Rep ; 7(1): 16824, 2017 12 04.
Artigo em Inglês | MEDLINE | ID: mdl-29203798

RESUMO

To reduce the ambiguity of contradictory observations in different studies regarding the expression level of Macrophage Inhibitory Cytokine-1 (MIC-1) in serum in prostate cancer (PC), benign prostatic hyperplasia (BPH) and healthy controls (HC), we designed this double-blind study. The study comprises 240 sera from PC, BPH and HC subjects. The expression level of MIC-1 in PC, BPH and HC were appraised using Western blot (WB) and ELISA based approach. WB and ELISA appraisal reveals that the expression level of MIC-1 is significantly higher in PC than in HC or BPH subjects. Regression analysis revealed a significant correlation between MIC-1 vs. PSA (r = 0.09; p < 0.001) and MIC-1 vs. GS (r = 0.7; p < 0.001). ROC analysis using discriminant predicted probability revealed that the MIC-1 was better than PSA. Moreover, the combination of MIC-1 and PSA was allowing 99.1% AUC for the differentiation of BPH + PC from HC, 97.9% AUC for differentiation of BPH from HC, 98.6% AUC for differentiation of PC from HC, and 96.7% AUC for the differentiation of PC from BPH. The augmented expression of MIC-1 in PC compared to BPH and HC subjects is in concurrent of the over-expression of MIC-1 in PC reports and confiscates the contradictory findings of other studies.


Assuntos
Fator 15 de Diferenciação de Crescimento/sangue , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/diagnóstico , Idoso , Área Sob a Curva , Western Blotting , Estudos de Casos e Controles , Método Duplo-Cego , Ensaio de Imunoadsorção Enzimática , Humanos , Masculino , Pessoa de Meia-Idade , Hiperplasia Prostática/sangue , Hiperplasia Prostática/diagnóstico , Neoplasias da Próstata/sangue , Curva ROC , Análise de Regressão , Estudos Retrospectivos
9.
Funct Integr Genomics ; 17(4): 477-490, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28285413

RESUMO

Withania somnifera (L.) Dunal (Family, Solanaceae), is among the most valuable medicinal plants used in Ayurveda owing to its rich reservoir of pharmaceutically active secondary metabolites known as withanolides. Withanolides are C28-steroidal lactones having a triterpenoidal metabolic origin synthesised via mevalonate (MVA) pathway and methyl-D-erythritol-4-phosphate (MEP) pathway involving metabolic intermediacy of 24-methylene (C30-terpenoid) cholesterol. Phytochemical studies suggest differences in the content and/or nature of withanolides in different tissues of different chemotypes. Though development of genomic resources has provided information about putative genes encoding enzymes for biosynthesis of intermediate steps of terpenoid backbone, not much is known about their regulation and response to elicitation. In this study, we generated detailed molecular information about genes catalysing key regulatory steps of withanolide biosynthetic pathway. The full-length sequences of genes encoding enzymes for intermediate steps of terpenoid backbone biosynthesis and their paralogs have been characterized for their functional and structural properties as well as phylogeny using bioinformatics approach. The expression analysis suggests that these genes are differentially expressed in different tissues (with maximal expression in young leaf), chemotypes and in response to salicylic acid (SA) and methyl jasmonate (MJ) treatments. Sub-cellular localization studies suggest that both paralogs of sterol ∆-7 reductase (WsDWF5-1 and WsDWF5-2) are localized in the endoplasmic reticulum (ER) thus supporting their indispensible role in withanolide biosynthesis. Comprehensive information developed, in this study, will lead to elucidation of chemotype- as well as tissue-specific withanolide biosynthesis and development of new tools for functional genomics in this important medicinal plant.


Assuntos
Regulação da Expressão Gênica de Plantas , Genes de Plantas , Withania/genética , Vitanolídeos/metabolismo , Retículo Endoplasmático/metabolismo , Oxirredutases/genética , Oxirredutases/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Transporte Proteico , Withania/metabolismo
10.
Acta Trop ; 162: 66-74, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27311385

RESUMO

Plasmodium vivax is the second major human malaria parasite that inflicts debilitating morbidity and consequent economic impact in South-East Asian countries. The relapsing nature of P. vivax along with the emergence of drug-resistant P. vivax strains has emphasized the urgent need for a vaccine. However, the development of an effective vivax vaccine is seriously hampered due to the diversity and variation in parasite antigens and non-availability of suitable animal models. DNA based vaccines represent an alternative approach in inducing immunity to multiple targets from different stages of malaria parasite. DNA prime-boosting strategies induce both antibody mediated and cell-mediated immune responses that are the major mechanisms of protection against malaria parasites. We have earlier studied the immunogenicity and protective efficacy of the soluble and refolded forms of recombinant 42kDa fragment of Plasmodium vivax merozoite surface protein-1 (PvMSP-142) using P. cynomolgi rhesus monkey model. In the present study, we have constructed a recombinant DNA vaccine encoding 42kDa fragment of P. vivax MSP-1 and studied the immunogenicity of PvMSP-142 DNA vaccine construct in mice. The 42kDa gene fragment of PvMSP-1 was PCR amplified using gene specific primers and subcloned into pcDNA 3.1 (+) eukaryotic expression vector. In vitro expression of PvMSP-142 plasmid construct was checked by transfection in COS-1 cell line. Indirect immunofluorescence of transfected COS-1 cells probed with monoclonal antibodies against PvMSP-142 exhibited positive fluorescence. Immunization of BALB/c mice with PvMSP-142-pcDNA vaccine construct revealed the immunogenicity of recombinant vaccine plasmid that can be enhanced by prime boosting with recombinant protein corresponding to the DNA vaccine as evidenced by significant elevation of antibody and the cytokines responses.


Assuntos
Vacinas Antimaláricas/imunologia , Malária Vivax/imunologia , Proteína 1 de Superfície de Merozoito/imunologia , Plasmídeos/imunologia , Plasmodium vivax/imunologia , Vacinas de DNA/genética , Vacinas de DNA/imunologia , Animais , Sudeste Asiático/epidemiologia , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Malária/prevenção & controle , Vacinas Antimaláricas/genética , Malária Vivax/epidemiologia , Proteína 1 de Superfície de Merozoito/genética , Camundongos , Camundongos Endogâmicos BALB C , Plasmodium vivax/genética , Proteínas Recombinantes/genética , Vacinação
11.
Future Microbiol ; 11(2): 195-214, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26855259

RESUMO

AIM: Wolbachia is a promising antifilarial chemotherapeutic target. Translation initiation factor-1 (Tl IF-1) is an essential factor in prokaryotes. Functional characterization of Wolbachia's novel proteins/enzymes is necessary for the development of adulticidal drugs. MATERIALS & METHODS: Mutant, Wol Tl IF-1 R45D was constructed by site directed mutagenesis. Fluorimetry and size exclusion chromatography were used to determine the biophysical characteristics. Mobility shift assay and fluorescence resonance energy transfer were used to investigate the functional aspect of Wol Tl IF-1 with its mutant. RESULTS: Both wild and mutant were in monomeric native conformations. Wild exhibits nonspecific binding with ssRNA/ssDNA fragments under electrostatic conditions and showed annealing and displacement of RNA strands in comparison to mutant. CONCLUSION: Point mutation impaired RNA chaperone activity of the mutant and its interaction with nucleotides.


Assuntos
Arginina , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Fator de Iniciação 1 em Procariotos/genética , Fator de Iniciação 1 em Procariotos/metabolismo , Wolbachia/genética , Wolbachia/metabolismo , Animais , Proteínas de Bactérias/química , Evolução Biológica , Brugia Malayi/microbiologia , DNA/metabolismo , Ensaio de Desvio de Mobilidade Eletroforética , Humanos , Mutagênese Sítio-Dirigida , Filogenia , Mutação Puntual , Fator de Iniciação 1 em Procariotos/química , Ligação Proteica , RNA/metabolismo , Alinhamento de Sequência
12.
J Ark Med Soc ; 112(3): 34-5, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26376553

RESUMO

Acute Superior Vena Cava (SVC) syndrome from thrombosis is an increasingly recognized complication of intravascular devices. We present a 31 year old woman with an infusion port placed for chemotherapy who developed acute SVC obstruction. A computerized tomograpy (CT) of chest revealed an occlusive thrombus within the SVC extending into the right atrium. Catheter-guided thrombolysis and surgical thrombectomywere felt to impose prohibitive risks. Worsening symptoms led to the use of systemic thrombolysis with tissue plasminogen activator (t-PA) leading to dramatic improvement in symptoms. A repeat CT revealed a reduction of the right atrial thrombus and SVC occlusion had resolved.


Assuntos
Síndrome da Veia Cava Superior/etiologia , Trombose/etiologia , Dispositivos de Acesso Vascular/efeitos adversos , Doença Aguda , Adulto , Feminino , Humanos , Síndrome da Veia Cava Superior/diagnóstico por imagem , Síndrome da Veia Cava Superior/tratamento farmacológico , Trombose/diagnóstico por imagem , Trombose/tratamento farmacológico , Ativador de Plasminogênio Tecidual/uso terapêutico , Tomografia Computadorizada por Raios X
13.
Open Respir Med J ; 9: 9-14, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25763116

RESUMO

BACKGROUND: Seasonal Influenza ("the flu") is a respiratory illness caused by influenza viruses. Yearly influenza vaccination is considered to be protective against illness and/or severity of illness and is recommended by CDC for all individuals > 6 months of age. However, the effectiveness of influenza vaccine in older individuals has come under question. OBJECTIVES: To describe the clinical characteristics and treatment outcomes of patients admitted to an academic tertiary care Veterans Administration hospital with influenza during the 2013-2014 influenza season and determine the impact, if any, of prior influenza vaccination upon patient outcomes. METHODS: Medical electronic records were searched for all patients admitted to the Little Rock Veterans Administration Hospital with proven influenza during the 2013-2014 influenza season. Cohorts of vaccinated and non-vaccinated patients were then compared to determine the impact of prior influenza vaccination upon respiratory-failure and mortality. RESULTS: Seventy patients met selection criteria. Mean age was 66 years. Sixty-four (91%) patients had at least one underlying co-morbid condition; these conditions included COPD, congestive heart failure, diabetes, and cancer. 60/70 (85%) tested positive for Influenza A, and 43 tested positive for H1N1. Oseltamivir was initiated in 55 (78%) patients. Forty-four percent of the patients had been vaccinated. When separated by vaccination status, those who had been vaccinated had higher rates of ICU admission, need for mechanical or non-invasive ventilation, and mortality. All but mortality reached statistical significance. CONCLUSION: The data suggest that there was no protective effect from prior vaccination in preventing hospital admission, respiratory failure, and mortality in this population of older men admitted to the hospital with influenza.

14.
Protein Expr Purif ; 103: 64-74, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25195175

RESUMO

Plasmodium vivax represents the second most prevalent malaria species of major public health importance and the global eradication of malaria requires the development of vaccines to prevent infection. The lack of in vitro culture and a suitable animal model for P. vivax malaria are the major problems for the delay in developing a functional vivax vaccine. A number of antigens have been identified for P. vivax as potential malaria vaccine candidates and among these 42kDa fragment of merozoite surface protein-1 (MSP-142) is one of most promising antigen of asexual blood stage. In most of the earlier studies, the MSP-142 of malaria parasites was expressed as insoluble protein in inclusion bodies and it is difficult to get purified protein in conformation form. In the present study, we have cloned, overexpressed and characterized the 42kDa fragment of P. vivax MSP-1 as soluble protein in Escherichiacoli. The 42kDa gene fragment of P. vivax MSP-1 was PCR amplified using specific primers, sequenced and subcloned into pTriEx-4 expression vector. The optimum expression of recombinant P. vivax protein was obtained in SOC growth medium by inducing with 0.2mM IPTG at 37°C for 4h. The SDS-PAGE analysis showed a fusion protein of 55kDa and about 80% was present in soluble form. The purified P. vivax MSP-142 was characterized and found to be correctly folded and in conformation form as evident by CD spectroscopy, presence of 1 free -SH group and the reactivity with reduction sensitive conformational monoclonals against P. vivax MSP-142.


Assuntos
Malária Vivax/prevenção & controle , Proteína 1 de Superfície de Merozoito/genética , Plasmodium vivax/química , Proteínas Recombinantes/genética , Animais , Sequência de Bases , Humanos , Vacinas Antimaláricas/genética , Malária Vivax/genética , Malária Vivax/imunologia , Proteína 1 de Superfície de Merozoito/biossíntese , Proteína 1 de Superfície de Merozoito/imunologia , Plasmodium vivax/imunologia , Plasmodium vivax/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/imunologia
15.
J Sci Food Agric ; 93(9): 2084-93, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23460190

RESUMO

In the last few years there has been an exponential growth in the field of herbal medicine, and these drugs are gaining popularity in both developing and developed countries because of their natural origin and lesser side effects. Syzygium cumini (syn. Eugenia jambolana, Syzygium jambolana, Eugenia cumini, Syzygium jambos), commonly known as jamun in India, is an evergreen tree distributed throughout the Indian subcontinent, Southeast Asia and East Africa. It is mainly utilised as a fruit producer and for its timber. Medicinally, the fruit is reported to have antidiabetic, antihyperlipidaemic, antioxidant, antiulcer, hepatoprotective, antiallergic, antiarthritic, antimicrobial, anti-inflammatory, antifertility, antipyretic, antiplaque, radioprotective, neuropsychopharmacological, nephroprotective and antidiarrhoeal activities. Among these beneficial physiological effects, the antidiabetic property of S. cumini has the most promising nutraceutical value. The health-beneficial effects of S. cumini are mainly attributed to various phytoconstituents such as tannins, alkaloids, steroids, flavonoids, terpenoids, fatty acids, phenols, minerals, carbohydrates and vitamins present in the fruit. This review paper presents an overview of experimental evidence for the pharmacological potential of S. cumini.


Assuntos
Compostos Fitoquímicos/farmacologia , Syzygium/química , África Oriental , Animais , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Sudeste Asiático , Descoberta de Drogas , Etnofarmacologia , Frutas/química , Humanos , Hipoglicemiantes/isolamento & purificação , Hipoglicemiantes/farmacologia , Hipoglicemiantes/uso terapêutico , Hipolipemiantes/isolamento & purificação , Hipolipemiantes/farmacologia , Hipolipemiantes/uso terapêutico , Índia , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/uso terapêutico , Casca de Planta/química , Folhas de Planta/química , Sementes/química , Syzygium/crescimento & desenvolvimento
16.
Microbiology (Reading) ; 157(Pt 11): 3180-3186, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-21873407

RESUMO

The nonadhesive mutant CD11 of Vibrio cholerae El Tor, defective in expression of mannose-sensitive haemagglutinin, lacks a protein when compared with its parent strain. Determination of the amino acid sequence revealed the identity of the protein as the product of VC1929, which is annotated to encode a protein, DctP, involved in the transport of C4-dicarboxylates. We cloned the dctP gene in pUC19 vector and expressed it in mutant CD11. Expression of DctP in the resulting complemented strain restored virulence, adhesive and colonizing capabilities, mannose-sensitive haemagglutination (MSHA) and ability to grow in medium containing sialic acid as a sole carbon source. The mutation in CD11 was caused by insertion of an adenine nucleotide in the reading frame of dctP. Recombinant purified DctP protein showed MSHA of human red blood cells, and protected rabbits against infection by V. cholerae. The protein was localized in membrane and cell wall fractions. The mutant, recombinant CD11 expressing DctP and parent strains were grown in M9 minimal medium in the presence of various carbohydrates (glucose, malate, fumarate, succinate or N-acetylneuraminic acid). The mutant was unable to grow in minimal medium containing N-acetylneuraminic acid (sialic acid) as the sole carbon source whereas the recombinant and parent strains utilized all the sugars tested. It is concluded that DctP is a mannose-sensitive haemagglutinin and a virulence factor and is involved in the utilization of sialic acid.


Assuntos
Proteínas de Bactérias/metabolismo , Transportadores de Ácidos Dicarboxílicos/metabolismo , Hemaglutinação , Manose/metabolismo , Ácido N-Acetilneuramínico/metabolismo , Vibrio cholerae/metabolismo , Animais , Aderência Bacteriana , Proteínas de Bactérias/genética , Clonagem Molecular , Transportadores de Ácidos Dicarboxílicos/genética , Teste de Complementação Genética , Testes de Hemaglutinação , Hemaglutininas/genética , Hemaglutininas/metabolismo , Humanos , Camundongos , Coelhos , Vibrio cholerae/genética , Vibrio cholerae/crescimento & desenvolvimento , Vibrio cholerae/patogenicidade , Virulência , Fatores de Virulência/genética , Fatores de Virulência/metabolismo
17.
Microbiology (Reading) ; 157(Pt 1): 29-37, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20884690

RESUMO

Acetohydroxyacid synthase (AHAS) is a biosynthetic enzyme essential for de novo synthesis of branched-chain amino acids. The genome sequence of Mycobacterium tuberculosis revealed genes encoding four catalytic subunits, ilvB1 (Rv3003c), ilvB2 (Rv3470c), ilvG (Rv1820) and ilvX (Rv3509c), and one regulatory subunit, ilvN (Rv3002c), of AHAS. All these genes were found to be expressed in M. tuberculosis growing in vitro. Each AHAS subunit gene was cloned and expressed in Escherichia coli. AHAS activity of IlvB1 and IlvG was found in cell-free lysates and with recombinant purified proteins. Kinetic studies with purified IlvG revealed positive cooperativity towards substrate and cofactors. To understand the role of the catalytic subunits in the biology of M. tuberculosis, expression of AHAS genes was analysed in different physiological conditions. ilvB1, ilvB2 and ilvG were differentially expressed. The role of ilvB1 in persistence is known, but the upregulation of ilvB2 and ilvG in extended stationary phase, ex vivo, and in acid stress and hypoxic environments, suggests the relevance of AHAS enzymes in the metabolism and survival of M. tuberculosis by functioning as catabolic AHAS. These enzymes are therefore potential targets for drug development.


Assuntos
Acetolactato Sintase/genética , Acetolactato Sintase/metabolismo , Mycobacterium tuberculosis/enzimologia , Transcrição Gênica , Animais , Clonagem Molecular , Modelos Animais de Doenças , Escherichia coli/genética , Perfilação da Expressão Gênica , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Viabilidade Microbiana , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Tuberculose/microbiologia
18.
Microbiology (Reading) ; 157(Pt 1): 38-46, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20864475

RESUMO

Dihydroxyacid dehydratase (DHAD), a key enzyme involved in branched-chain amino acid (BCAA) biosynthesis, catalyses the synthesis of 2-ketoacids from dihydroxyacids. In Mycobacterium tuberculosis, DHAD is encoded by gene Rv0189c, and it shares 40% amino acid sequence identity and conserved motifs with DHAD of Escherichia coli encoded by ilvD. In this study, Rv0189c was overexpressed in E. coli and the resultant protein was characterized as a homodimer (~155 kDa). Functional characterization of Rv0189c was established by biochemical testing and by genetic complementation of an intron-disrupted ilvD-auxotrophic mutant of E. coli to prototrophy. Growth of M. tuberculosis, E. coli BL21(DE3) and recombinant E. coli BL21(DE3) ΔilvD carrying Rv0189c was inhibited by transient nitric oxide (NO) exposure in minimal medium but growth was restored if the medium was supplemented with BCAA (isoleucine, leucine and valine). This suggested that inactivation of Rv0189c by NO probably inhibited bacterial growth. The role of Rv0189c in M. tuberculosis was elucidated by antisense and sense RNA constructs. Growth of M. tuberculosis transformed with a plasmid encoding antisense mRNA was markedly poor in the lungs of infected mice and in Middlebrook 7H9 broth compared to that of sense and vector-alone transformants, but growth was normal when the medium was supplemented with BCAA. Upregulation of Rv0189c was observed during the early exponential phase of growth, under acid stress and ex vivo, suggesting that Rv0189c has a role in the survival of M. tuberculosis during normal and stress conditions. It may be concluded that the DHAD encoded by Rv0189c is essential for the survival of M. tuberculosis and could be a potential drug/vaccine target, as it is absent in mammals.


Assuntos
Proteínas de Bactérias/metabolismo , Hidroliases/metabolismo , Mycobacterium tuberculosis/enzimologia , Mycobacterium tuberculosis/crescimento & desenvolvimento , Fatores de Virulência/metabolismo , Aminoácidos de Cadeia Ramificada/metabolismo , Animais , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Clonagem Molecular , Meios de Cultura/química , Modelos Animais de Doenças , Regulação para Baixo , Escherichia coli/genética , Deleção de Genes , Expressão Gênica , Inativação Gênica , Teste de Complementação Genética , Hidroliases/química , Hidroliases/genética , Pulmão/microbiologia , Camundongos , Camundongos Endogâmicos BALB C , Mycobacterium tuberculosis/patogenicidade , Óxido Nítrico/toxicidade , Multimerização Proteica , Tuberculose Pulmonar/microbiologia , Fatores de Virulência/química , Fatores de Virulência/genética
19.
Indian J Biochem Biophys ; 47(4): 227-33, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21174950

RESUMO

Diabetes is an oxidative stress disorder and oxidative damage to tissues such as heart, kidney, liver and other organs may be a contributory factor to several diabetic complications. Momordica charantia (family: Cucurbitaceae) and Trigonella foenum graecum (family: Fabaceae) are used traditionally in Indian folk medicine to manage diabetes mellitus. In the present study, the anti-hyperglycemic and anti-oxidative potential of aqueous extracts of M. charantia pulp and seed powder of T. foenum graecum were assessed in alloxan (150 mg/kg body weight) induced diabetic rats. Alloxan treatment to the rats could induce diabetes as the fasting blood glucose (FBG) levels were > 280 mg/dl. Treatment of diabetic rats for 30 days with M. charantia and T. foenum graecum could significantly (p < 0.001) improve the FBG levels to near normal glucose levels. Antioxidant activities (superoxide dismutase, catalase, reduced glutathione content and glutathione-s-transferase) and lipid peroxidation levels were measured in heart, kidney and liver tissues of normal, diabetic and experimental animals (diabetics + treatment). TBARS levels were significantly (p < 0.001) higher and anti-oxidative activities were found low in diabetic group, as compared to the control group. Significant (p < 0.001) improvement in both the TBARS levels and antioxidant activities were observed when M. charantia and T. foenum graecum were given to diabetic rats. Our results clearly demonstrate that M. charantia and T. foenum graecum are not only useful in controlling the blood glucose levels, but also have antioxidant potential to protect vital organs such as heart and kidney against damage caused due to diabetes induced oxidative stress.


Assuntos
Aloxano/química , Antioxidantes/farmacologia , Diabetes Mellitus Experimental/tratamento farmacológico , Hipoglicemiantes/farmacologia , Animais , Antioxidantes/química , Glutationa/química , Masculino , Momordica charantia/metabolismo , Estresse Oxidativo , Extratos Vegetais/química , Ratos , Ratos Wistar , Sementes/química , Substâncias Reativas com Ácido Tiobarbitúrico/química , Trigonella/metabolismo
20.
Proteomics ; 10(9): 1730-9, 2010 May.
Artigo em Inglês | MEDLINE | ID: mdl-20162559

RESUMO

Kaempferol, a flavonoid, promotes osteoblast mineralization in vitro and bone formation in vivo; however, its mechanism of action is yet unknown. We adopted proteomic approach to identify the differential effect of kaempferol on rat primary calvarial osteoblasts during mineralization. The primary rat calvarial osteoblasts were treated with kaempferol (5.0 microM) for 9 days under mineralizing condition that resulted in significant increase in alkaline phosphatase activity and mineralization of the cells. Further, 2-D analysis of the kaempferol-treated osteoblast lysates revealed 18 differentially expressed proteins (nine upregulated and nine downregulated) on the basis of >/<2.0-fold as cut-off (p<0.01) that were then identified by MALDI-TOF MS. These included cytoskeletal proteins, intracellular signaling protein, chaperone, extracellular matrix protein, and proteins involved in glycolysis and cell-matrix interactions. Proteomics data were confirmed by Western blotting and quantitative real-time PCR by randomly selecting two upregulated and two downregulated proteins. Western blot analysis confirmed upregulation of HSP-70 and cytokeratin-14 levels, and downregulation of aldose reductase and caldesmon expression. We further demonstrated that kaempferol treatment inhibits aldose reductase activity in osteoblasts indicating an altered cellular metabolism by decelerating polyol pathway that was associated with the kaempferol-induced osteoblast mineralization. In conclusion, this is a first comprehensive study on the differential regulation of proteins by kaempferol in primary osteoblast, which would further help to elucidate the role of the identified proteins in the process of osteoblast mineralization.


Assuntos
Quempferóis/farmacologia , Osteoblastos/química , Osteoblastos/efeitos dos fármacos , Crânio/química , Crânio/efeitos dos fármacos , Aldeído Redutase/genética , Fosfatase Alcalina/metabolismo , Animais , Células Cultivadas , Regulação para Baixo/efeitos dos fármacos , Feminino , Proteínas de Choque Térmico HSP70/genética , Queratina-14/genética , Masculino , Osteoblastos/metabolismo , Proteômica , RNA Mensageiro/genética , Ratos , Ratos Sprague-Dawley , Regulação para Cima/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...