RESUMO
INTRODUCTION: Osteonecrosis of the jaw (ONJ) is an adverse event that requires association of both systemic risk factors, such as powerful anti-resorptives (pARs; e.g. zoledronic acid [ZOL]), and local oral risk factors (e.g. tooth extraction, periodontitis). Whereas optimal oral health prior to initiate pARs is recognized as critically important for minimizing ONJ risk, the efficacy of preventive/maintenance measures in patients who are taking pARs is understudied. Rice rats fed a standard diet (STD), rich in insoluble fiber, develop localized periodontitis. STD-rats with localized periodontitis treated with ZOL for 18-24 wk develop ONJ. Hence, we hypothesized that controlling/preventing localized periodontitis in the ZOL-treated rats, reduces ONJ occurrence. METHODS: We used two approaches to attempt reducing periodontitis prevalence: 1) periodontal cleaning (PC); and 2) replacing the STD-diet with a nutritionally-equivalent diet high in soluble fiber (SF). 75 four-week-old male rats were weight-randomized into five groups (n = 15) in a 24-week experiment. Three groups ate the STD-diet and two the high SF-diet. STD-diet groups received intravenous (IV) vehicle (VEH) q4wks (STD + VEH), 80 µg/kg ZOL q4wks IV (STD + ZOL), or ZOL plus PC q2wks (STD + ZOL + PC). The SF-diet groups received VEH (SF + VEH) or ZOL (SF + ZOL). Jaws were processed for histopathology and evaluated for ONJ prevalence and tissue-level periodontitis. RESULTS: 1) 40% of STD + VEH rats developed maxillary localized periodontitis with no ONJ; 2) 50% of STD + ZOL rats developed ONJ; 3) 7% of STD + ZOL + PC rats developed ONJ (p < 0.01 vs. STD + ZOL); and 4) one SF + ZOL rat developed localized periodontitis, and no SF + VEH or SF + ZOL rats developed ONJ (p < 0.001 vs. STD + ZOL). CONCLUSIONS: 1) Periodontal cleaning in ZOL-treated rats decreases localized periodontitis severity and reduces ONJ prevalence; and 2) feeding a SF-diet to ZOL-treated rats reduces both incidence of localized periodontitis and ONJ. Our data indicates strong oral microbial community shifts according to oral health condition and trends in the shifts associated with diet.
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Osteonecrose da Arcada Osseodentária Associada a Difosfonatos , Conservadores da Densidade Óssea , Osteonecrose , Periodontite , Animais , Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/prevenção & controle , Difosfonatos/uso terapêutico , Humanos , Arcada Osseodentária , Masculino , Periodontite/prevenção & controle , Ratos , Sigmodontinae , Ácido ZoledrônicoRESUMO
OBJECTIVE: Angiogenesis inhibitors (AgI) are commonly used in combination chemotherapy protocols to treat cancer, and have been linked to osteonecrosis of the jaw (ONJ). However, it is unknown if AgI therapy alone is sufficient to induce ONJ. We have previously established an ONJ model in rice rats with localized periodontitis that receive zoledronic acid (ZOL). The purpose of this study was to use this model to determine the role of anti-vascular endothelial growth factor A (anti-VEGF) antibody treatment of rice rats with localized maxillary periodontitis. We hypothesized that rice rats with localized maxillary periodontitis given anti-VEGF monotherapy will develop oral lesions that resemble ONJ, defined by exposed, necrotic alveolar bone. METHODS: At age 4â¯weeks, 45 male rice rats were randomized into three groups (nâ¯=â¯15): 1) VEH (saline), 2) ZOL (80⯵g/kg body weight, intravenously once monthly), and 3) anti-VEGF (5â¯mgâ¯B20-4.1.1/kg body weight, subcutaneously twice weekly). After 24â¯weeks, rats were euthanized, jaws were excised and a high-resolution photograph of each quadrant was taken to assign a severity grade based on gross appearance. Jaws were then fixed, scanned by MicroCT, decalcified and sectioned for histopathologic and immunohistochemical analyses. RESULTS: 40-80% of the rats in the three groups developed gross oral lesions. 50% of ZOL rats developed ONJ. In contrast, 80% of the anti-VEGF rats developed destructive advanced periodontitis that was characterized by extreme alveolar bone loss and fibrosis. Anti-VEGF rats never developed exposed, necrotic bone. Furthermore, only anti-VEGF rats developed mild to severe mandibular periodontitis. Compared to VEH rats, more T-cells were found in periodontal lesions of anti-VEGF rats and more cells of the monocyte lineage were found in ONJ lesions of ZOL rats. CONCLUSIONS: Anti-VEGF monotherapy administered to a validated rodent model of ONJ caused a destructive advanced form of periodontitis that differed significantly from ONJ.
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Osteonecrose da Arcada Osseodentária Associada a Difosfonatos , Osteonecrose , Periodontite , Animais , Osteonecrose da Arcada Osseodentária Associada a Difosfonatos/diagnóstico por imagem , Difosfonatos/efeitos adversos , Masculino , Periodontite/tratamento farmacológico , Ratos , Sigmodontinae , Microtomografia por Raio-X , Ácido Zoledrônico/efeitos adversosRESUMO
Dengue virus type 1 (DENV-1) Asian and American/African (AM/AF) genotypes were reported to be co-circulating in southern and western states of India based on envelope (E) gene sequencing of few representative samples. The objective of the present study was to develop a one-step real-time RT-PCR to discriminate between Asian and AM/AF genotypes of DENV-1 and investigate the spatio-temporal distribution of the DENV-1 genotypes in southern and western states of India. A one-step real-time RT-PCR to discriminate the Asian and AM/AF genotypes of DENV-1 was developed and validated using 40 samples (17 Asian and 23â¯AM/AF), for which the envelope (E) gene sequence data was available. DENV-2, DENV-3 and DENV-4 isolates, one each and DENV negative samples (nâ¯=â¯17) were also tested by the assay. Additional 296 samples positive for DENV-1 from selected Southern and Western states of India were genotyped using the real-time RT-PCR assay. Among the samples used for validation, the genotyping results were concordant with sequencing results for 39 samples. In the one discordant sample which was positive for AM/AF by sequencing, the genotyping assay tested positive for both Asian and AM/AF genotype. DENV-2, DENV-3 and DENV-4 isolates were not reactive in the assay. None of the DENV negative samples were positive (sensitivity 100% and specificity 98.2%). A total of 336 samples (40 samples with sequence data and 296 samples without sequence data) were used for spatio-temporal distribution analysis. The results revealed that the Asian genotype was the predominant genotype in Tamil Nadu and Kerala, the southern states. The AM/AF genotype was the predominant genotype in Maharashtra, a western state of India. In Nashik district of Maharashtra, Asian genotype was observed in 32.6% of DENV-1 samples during 2017 while the same decreased to 7.3% during 2018. In Pune district, Asian genotype was observed in 40.0% of DENV-1 samples during 2018 only. To conclude, a one step real-time RT-PCR has been developed for discriminating Asian and AM/AF genotypes of DENV-1. This assay can act as a complement to sequencing but not a substitute and can be utilized in resource limited settings for molecular surveillance of DENV-1. DENV-1 Asian genotype was the dominant genotype in South India while, AM/AF genotype was dominant in Western India.
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Vírus da Dengue/classificação , Dengue/diagnóstico , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Proteínas do Envelope Viral/genética , Ásia , Vírus da Dengue/genética , Genótipo , Humanos , Índia , Filogenia , Sensibilidade e Especificidade , Análise de Sequência de RNA , Análise Espaço-TemporalRESUMO
BACKGROUND AND PURPOSE: Dengue is a common arboviral disease, which uncommonly involves the brain. There has been a recent surge in dengue cases and dengue-related deaths in tropical countries. The aim of this study was to describe brain imaging findings in patients with dengue infection having neurologic symptoms. MATERIALS AND METHODS: Thirty-five patients with positive serology for dengue with CNS symptoms undergoing imaging of the brain were included in the study. Clinical, laboratory, and imaging parameters were assessed and correlated to poor outcome. RESULTS: A Glasgow Coma Scale score of ≤12 at presentation, clinical classification of severe-type dengue, and the presence of acute renal failure were associated with poor outcome. Imaging parameters associated with poor outcome were involvement of the thalami and cerebellar peduncles and the presence of diffusion restriction and hemorrhagic foci in the brain parenchyma. CONCLUSIONS: Although not specific, dengue infection has imaging findings that can be used to narrow down the differential list and help in prognostication.
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Encefalopatias/diagnóstico por imagem , Encefalopatias/virologia , Dengue/complicações , Dengue/diagnóstico por imagem , Adolescente , Adulto , Criança , Feminino , Escala de Coma de Glasgow , Humanos , Masculino , Pessoa de Meia-Idade , Neuroimagem , Adulto JovemRESUMO
BACKGROUND & OBJECTIVES: Rapid diagnostic test (RDT) kits are widely used in India for the diagnosis of dengue infection. It is important to evaluate the validity and reliability of these RDTs. The study was aimed to determine the sensitivity, specificity and predictive value of four commercially available RDTs [Panbio Dengue Duo cassette, Standard Diagnostics (SD) Bioline Dengue Duo, J. Mitra Dengue Day-1 test and Reckon Dengue IgG/IgM] against composite reference criteria (CRC), and compare the cost of the tests. METHODS: In this prospective observational study for diagnostic accuracy, we tested stored blood samples from 132 cases of dengue and 149 controls of other infections as classified based on CRC, with all the four RDTs. The CRC was based on the epidemiological considerations, common clinical features and laboratory abnormalities. The non-dengue controls were the cases of proven alternative diagnosis. The diagnostic performances of the tests were compared in terms of sensitivity, specificity and predictive value along with the cost involved per test. RESULTS: The sensitivity of the Panbio and SD RDT kits was found to be 97.7 and 64.3% respectively, and the specificities were 87.8 and 96.6% respectively. The sensitivity of the NS1 antigen capture by SD Duo, Reckon, J. Mitra RDTs was 20.9, 18.6 and 27.1% respectively. The prevalence of dengue specific IgG antibody with Panbio RDT kits was 49.3%. The cost per test for Panbio, SD, Reckon and J. Mitra is US$ 6.90, 4.27, 3.29 and 3.61 respectively. CONCLUSION: It was concluded that in dengue outbreak, Panbio IgM capture RDT alone is reliable and easily available test which can be used in acute phase of dengue infection in any resource limited set up. NS1 capture rates by any of the other three RDTs might not be reliable for the diagnosis of acute dengue infection.
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Análise Custo-Benefício , Dengue/diagnóstico , Testes Diagnósticos de Rotina/economia , Testes Diagnósticos de Rotina/métodos , Adulto , Animais , Cromatografia de Afinidade/economia , Cromatografia de Afinidade/métodos , Estudos Transversais , Feminino , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Prospectivos , Sensibilidade e Especificidade , Fatores de Tempo , Adulto JovemRESUMO
BACKGROUND: Epstein-Barr virus (EBV)-associated gastric carcinoma is a relatively uncommon entity detected in approximately 10% of gastric adenocarcinoma. OBJECTIVE: The purpose of this study is to estimate the frequency of EBV-associated gastric carcinoma and also to assess the nature of presentation, any significant difference between this subgroup and EBV-negative gastric adenocarcinomas with respect to age and sex predilection, lymph nodal status, site of presentation. MATERIALS AND METHODS: We prospectively analyzed 100 cases of gastric adenocarcinoma who underwent either a partial or total gastrectomy during the period from March 2010 to August 2011. The tumour and the corresponding normal gastric tissue from the same patient were analyzed for the presence of Epstein-Barr nuclear antigen 1 (EBNA1) messenger ribonucleic acid (mRNA) by real-time polymerase chain reaction (PCR). RESULT: EBV was detected in 6% cases of gastric adenocarcinoma. All the positive patients were males. The majority of cases involved the proximal stomach and there was variable lymph nodal involvement. CONCLUSION: Our study endorses that there is an association between EBV infection and gastric adenocarcinoma in the Indian population. There was no significant difference between this subgroup and EBV-negative gastric adenocarcinomas with respect to age and sex predilection, lymph nodal status and site of presentation. Short-term follow-up of this subgroup of patients seems to indicate a good overall prognosis after appropriate treatment. However, a larger study with long-term follow-up is needed to further establish the role of EBV in gastric adenocarcinoma in this study population.
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Adenocarcinoma/virologia , Infecções por Vírus Epstein-Barr/epidemiologia , Antígenos Nucleares do Vírus Epstein-Barr/genética , Herpesvirus Humano 4/isolamento & purificação , RNA Mensageiro/análise , RNA Viral/análise , Neoplasias Gástricas/virologia , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Infecções por Vírus Epstein-Barr/complicações , Infecções por Vírus Epstein-Barr/virologia , Feminino , Humanos , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Reação em Cadeia da Polimerase em Tempo Real , Centros de Atenção TerciáriaRESUMO
PURPOSE: Opportunistic viral infections are one of the major causes of morbidity and mortality in HIV infection and their molecular detection in the whole blood could be a useful diagnostic tool. OBJECTIVE: The frequency of opportunistic DNA virus infections among HIV-1-infected individuals using multiplex real-time PCR assays was studied. MATERIALS AND METHODS: The subjects were in two groups; group 1: Having CD4 counts<100 cells/µl (n=118) and the group 2: counts>350 cells/µl (n=173). Individuals were classified by WHO clinical staging system. Samples from 70 healthy individuals were tested as controls. In-house qualitative multiplex real-time PCR was standardised and whole blood samples from 291 were tested, followed by quantitative real-time PCR for positives. In a proportion of samples genotypes of Epstein-Barr virus (EBV) and CMV were determined. RESULTS: The two major viral infections observed were EBV and CMV. The univariate analysis of CMV load showed significant association with cryptococcal meningitis, oral hairy leukoplakia (OHL), CMV retinitis, CD4 counts and WHO staging (P<0.05) while the multivariate analysis showed an association with OHL (P=0.02) and WHO staging (P=0.05). Univariate analysis showed an association of EBV load with CD4 counts and WHO staging (P<0.05) and multivariate analysis had association only with CD4 counts. The CMV load was significantly associated with elevated SGPT and SGOT level (P<0.05) while the EBV had only with SGOT. CONCLUSION: This study showed an association of EBV and CMV load with CD4+ T cell counts, WHO staging and elevated liver enzymes. These viral infections can accelerate HIV disease and multiplex real-time PCR can be used for the early detection. Genotype 1 and 2 of EBV and genotype gB1 and gB2 of CMV were the prevalent in the HIV-1 subtype C-infected south Indians.
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Sangue/virologia , Infecções por Citomegalovirus/epidemiologia , Citomegalovirus/isolamento & purificação , Infecções por Vírus Epstein-Barr/epidemiologia , Infecções por HIV/complicações , Herpesvirus Humano 4/isolamento & purificação , Contagem de Linfócito CD4 , Infecções por Citomegalovirus/virologia , Infecções por Vírus Epstein-Barr/virologia , HIV-1/isolamento & purificação , Humanos , Reação em Cadeia da Polimerase Multiplex , Prevalência , Reação em Cadeia da Polimerase em Tempo Real , Carga ViralRESUMO
Dopaminergic medication in Parkinson's disease has been proposed to improve cognitive processing by modulating the severely depleted dorsal striatum, while impairing reward processing by modulating the relatively intact ventral striatum. However, there is no direct (neural) evidence for this hypothesis. Here we fill this gap by scanning Parkinson's disease patients (n=15) ON and relatively OFF their dopaminergic medication using functional magnetic resonance imaging. During scanning, patients performed a task that enabled the simultaneous measurement of task-switching and reward-related processing. Brain-behavior correlations revealed that medication-related increases (ON-OFF) in switch-related BOLD signal (switch-repeat) in the dorsomedial striatum were associated, on an individual basis, with improvements in task-switching (i.e. a decreased switch cost). Conversely, medication-related increases (ON-OFF) in reward-related BOLD signal (high-low) in the ventromedial striatum were associated, on an individual basis, with impairments in performance in anticipation of reward (i.e. an increased reward cost). Linear regression analyses demonstrated that the positive relationship between medication-related changes in BOLD and the reward cost was unique to the ventromedial striatum, whereas the negative relationship between medication-related changes in BOLD and the switch cost was not unique to the dorsomedial striatum. These findings extend the dopamine overdose hypothesis, according to which dopamine-induced changes in dorsal and ventral striatal processing lead to cognitive improvement and impairment respectively.
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Antiparkinsonianos/farmacologia , Atenção/fisiologia , Corpo Estriado/efeitos dos fármacos , Dopaminérgicos/farmacologia , Doença de Parkinson/patologia , Recompensa , Antiparkinsonianos/uso terapêutico , Aprendizagem por Associação/efeitos dos fármacos , Atenção/efeitos dos fármacos , Corpo Estriado/irrigação sanguínea , Dopaminérgicos/uso terapêutico , Eletromiografia , Feminino , Lateralidade Funcional , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Oxigênio/sangue , Doença de Parkinson/tratamento farmacológico , Tempo de Reação/efeitos dos fármacosRESUMO
Human herpes virus-8 (HHV-8) is etiologically associated with Kaposi's sarcoma. There is insufficient information on the epidemiology of HHV-8 infection from India. Blood samples from 87 human immunodeficiency virus (HIV)-infected individuals and 84 normal healthy blood donors were tested for the HHV-8 IgG antibodies. Further, a total of 309 whole blood samples from treatment-naïve HIV-1-infected individuals and from 70 normal healthy individuals were also collected and tested for HHV-8 DNA. The seroprevalence of HHV-8 was 4.7% in the South Indian population. There was no significant difference in the seroprevalence of HHV-8 in the HIV-infected and uninfected patients. None of the 379 samples tested were positive for HHV-8 DNA. Our study revealed a very low exposure of the South Indian patient population to HHV-8 and multicentric epidemiological studies are needed to understand the prevalence of HHV-8 in different regions of India and to confirm any gender-specific differences in seroprevalence.
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Coinfecção/epidemiologia , Infecções por HIV/complicações , Infecções por Herpesviridae/epidemiologia , Herpesvirus Humano 8/imunologia , Adulto , Anticorpos Antivirais/sangue , Sangue/virologia , Doadores de Sangue , Coinfecção/virologia , Estudos Transversais , Feminino , Infecções por Herpesviridae/virologia , Humanos , Imunoglobulina G/sangue , Índia/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Soroepidemiológicos , Adulto JovemRESUMO
Caldicellulosiruptor saccharolyticus is one of the most thermophilic cellulolytic organisms known to date. This Gram-positive anaerobic bacterium ferments a broad spectrum of mono-, di- and polysaccharides to mainly acetate, CO2 and hydrogen. With hydrogen yields approaching the theoretical limit for dark fermentation of 4 mol hydrogen per mol hexose, this organism has proven itself to be an excellent candidate for biological hydrogen production. This review provides an overview of the research on C. saccharolyticus with respect to the hydrolytic capability, sugar metabolism, hydrogen formation, mechanisms involved in hydrogen inhibition, and the regulation of the redox and carbon metabolism. Analysis of currently available fermentation data reveal decreased hydrogen yields under non-ideal cultivation conditions, which are mainly associated with the accumulation of hydrogen in the liquid phase. Thermodynamic considerations concerning the reactions involved in hydrogen formation are discussed with respect to the dissolved hydrogen concentration. Novel cultivation data demonstrate the sensitivity of C. saccharolyticus to increased hydrogen levels regarding substrate load and nitrogen limitation. In addition, special attention is given to the rhamnose metabolism, which represents an unusual type of redox balancing. Finally, several approaches are suggested to improve biohydrogen production by C. saccharolyticus.
RESUMO
PURPOSE: To compare a conventional polymerase chain reaction (PCR) and real-time PCR for the detection of neurotropic DNA viruses. MATERIALS AND METHODS: A total of 147 cerebrospinal fluid (CSF) samples was collected from patients attending a tertiary care hospital in South India for a period from 2005 to 2008. All these samples were tested using a conventional multiplex/uniplex PCR and a real-time multiplex/uniplex PCR. This technique was used to detect a large number of herpes viruses responsible for central nervous system infections, including HSV-1, HSV-2, VZV, CMV and EBV and the polyoma virus JCV. RESULTS: Overall, in the entire set of samples, the real-time PCR yielded 88 (59.9%) positives and conventional PCR had six (4.1%) positives. CONCLUSION: Our results suggest that the real-time PCR assay was more sensitive compared with the conventional PCR. The advantage of real-time PCR is that it can be performed much faster than conventional PCR. Real-time PCR is less time-consuming, less labour-intensive and also reduces the chance of contamination as there is no post-amplification procedure. In the entire study population, the major viruses detected using real-time PCR were EBV (34%), HSV-2 (10.8%) and VZV (6.8%).
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Líquido Cefalorraquidiano/virologia , Técnicas de Laboratório Clínico/métodos , Herpesviridae/isolamento & purificação , Vírus JC/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Virologia/métodos , Viroses/diagnóstico , Humanos , Índia , Prevalência , Sensibilidade e Especificidade , Viroses/virologiaRESUMO
Influenza virus is prone to mutations that may alter the intensity of subsequent waves of infection. In this study, we evaluated whether outcomes were different in the two waves of the influenza A (H1N1) 2009 pandemic in patients admitted to the intensive-care unit. Age, gender, lag-time to presentation and APACHE-II scores were similar in both waves. Although ventilatory requirements were similar (36/37 vs. 36/39), non-significant reductions in the durations (days) of ventilation (10.3 ± 8.0 vs. 7.8 ± 9.4, p 0.11) and hospitalization (14.9 ± 10.5 vs. 12.3 ± 14.1, p 0.20) were observed in the second wave. The clinical profile and outcomes were not significantly different between the two waves among severely ill patients.
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Vírus da Influenza A Subtipo H1N1 , Influenza Humana/epidemiologia , Influenza Humana/virologia , Pandemias , Adulto , Estudos de Coortes , Feminino , Humanos , Índia/epidemiologia , Unidades de Terapia Intensiva/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Fatores de RiscoAssuntos
Estado Terminal , Pessoal de Saúde , Transmissão de Doença Infecciosa do Paciente para o Profissional/estatística & dados numéricos , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Influenza Humana/transmissão , Adulto , Cuidados Críticos , Feminino , Humanos , Influenza Humana/virologia , Masculino , Medição de RiscoRESUMO
Rubella, a mild, vaccine-preventable disease, can manifest as congenital rubella syndrome (CRS), a devastating disease of the fetus. To emphasize the inadequacy of the existing rubella vaccination programme in India, we evaluated epidemiological evidence of rubella virus activity with data available from a tertiary-care centre. The proportion of suspected CRS cases that were laboratory confirmed increased from 4% in 2000 to 11% in 2008. During the same period, 329 clinically suspected postnatal rubella cases were tested of which 65 (20%) were laboratory confirmed. Of women (n=770) of childbearing age, 12·5% were susceptible to rubella.
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Síndrome da Rubéola Congênita/epidemiologia , Rubéola (Sarampo Alemão)/epidemiologia , Adolescente , Adulto , Fatores Etários , Criança , Pré-Escolar , Feminino , Humanos , Índia/epidemiologia , Lactente , Masculino , Rubéola (Sarampo Alemão)/prevenção & controle , Síndrome da Rubéola Congênita/prevenção & controle , Vacina contra Rubéola/uso terapêutico , Adulto JovemRESUMO
Hydrogen produced from biomass by bacteria and archaea is an attractive renewable energy source. However, to make its application more feasible, microorganisms are needed with high hydrogen productivities. For several reasons, hyperthermophilic and extremely thermophilic bacteria and archaea are promising is this respect. In addition to the high polysaccharide-hydrolysing capacities of many of these organisms, an important advantage is their ability to use most of the reducing equivalents (e.g. NADH, reduced ferredoxin) formed during glycolysis for the production of hydrogen, enabling H2/hexose ratios of between 3.0 and 4.0. So, despite the fact that the hydrogen-yielding reactions, especially the one from NADH, are thermodynamically unfavourable, high hydrogen yields are obtained. In this review we focus on three different mechanisms that are employed by a few model organisms, viz. Caldicellulosiruptor saccharolyticus and Thermoanaerobacter tengcongensis, Thermotoga maritima, and Pyrococcus furiosus, to efficiently produce hydrogen. In addition, recent developments to improve hydrogen production by hyperthermophilic and extremely thermophilic bacteria and archaea are discussed.
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Archaea/metabolismo , Bactérias/metabolismo , Biomassa , Hidrogênio/metabolismo , Microbiologia Industrial/métodos , Oxirredução , TermodinâmicaRESUMO
The role of inorganic pyrophosphate (PPi) as an energy carrier in the central metabolism of the extremely thermophilic bacterium Caldicellulosiruptor saccharolyticus was investigated. In agreement with its annotated genome sequence, cell extracts were shown to exhibit PPi-dependent phosphofructokinase and pyruvate phosphate dikinase activity. In addition, membrane-bound pyrophosphatase activity was demonstrated, while no significant cytosolic pyrophosphatase activity was detected. During the exponential growth phase, high PPi levels (approximately 4 +/- 2 mM) and relatively low ATP levels (0.43 +/- 0.07 mM) were found, and the PPi/ATP ratio decreased 13-fold when the cells entered the stationary phase. Pyruvate kinase activity appeared to be allosterically affected by PPi. Altogether, these findings suggest an important role for PPi in the central energy metabolism of C. saccharolyticus.
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Difosfatos/metabolismo , Metabolismo Energético , Bactérias Gram-Positivas/metabolismo , Hidrogênio/metabolismo , Trifosfato de Adenosina/metabolismo , Proteínas de Bactérias/metabolismo , Membrana Celular/metabolismo , Bactérias Gram-Positivas/crescimento & desenvolvimento , Fosfofrutoquinases/metabolismo , Pirofosfatases/metabolismo , Piruvato Ortofosfato Diquinase/metabolismoRESUMO
The development and potential application of nanotechnology tools for single-virus particle detection by emergent nanotechnology is likely to revolutionize diagnosis and determining treatment endpoints for life threatening virus infections. Direct detection of biological macromolecules using semiconducting nanowires or carbon nanotubes for electrical field change measurements is a milestone application in this field. The promise of selective detection at a single particle level (stochastic sensing) with nanowire or nanotube field-effect transistor-based devices is a major breakthrough for outbreak situations, where a rapid and specific detection of the viral agent allows intervention at public health level. The same technology would be eminently suitable for bedside diagnosis and therapeutic intervention.
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Nanotecnologia/métodos , Vírion/isolamento & purificação , Viroses/diagnóstico , Humanos , Nanotubos de CarbonoRESUMO
PURPOSE: Opportunistic viral infections cause increased morbidity and mortality among human immunodeficiency virus (HIV) infected individuals, especially those who are not on antiretroviral treatment. Early diagnosis of these opportunistic viruses will be able to reduce the risk of disease progression with appropriate intervention. MATERIALS AND METHODS: Multiplex PCR was attempted to detect the opportunistic herpes viruses (HSV-1, HSV-2, VZV, EBV, and CMV), adenovirus and polyoma viruses (JC and BK) in three cocktails of PCR reactions. Subsequently, all the viruses detected were quantitated by testing using monoplex real time PCR. Whole blood samples collected between 2006 and 2007 from 68 treatment naïve HIV-1 infected and 30 normal healthy individuals were tested for these eight viruses. Among the 68 HIV-1 infected individuals 35 had CD4+ T cell count less than or equal to 200 while the other 33 had greater than 200 CD4+ T cells. RESULTS: Among the 68 HIV-1 infected individuals, 49 (72%) were positive for EBV, 5 (7%) samples were positive for CMV. All the five CMV positive individuals had CD4+ T cell count of less than or equal to 200 cells/microL. The mean EBV load among the individuals with a CD4+ T cells of less than or equal to 200 cells/microL was 3.88 log(10) while among those with greater than 200 CD4+ T cells it was 3.75 log(10) . The mean CMV load was 6.98 log(10). Three samples were positive for both CMV & EBV. None of the samples was positive for HSV-1, HSV-2, VZV, Adenovirus, JC and BK viruses. CONCLUSIONS: In our study, multiplex PCR based detection system was found useful in detecting opportunistic viruses in HIV infected individuals. Though EBV is the most prevalent opportunistic viral infection among HIV infected individuals, there was no significant association between EBV load, CD4+ T cell counts and HIV-1 virus load. CMV was seen in HIV infected individuals with low CD4+ T cell counts (less than 200 cells/microL).
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Infecções Oportunistas Relacionadas com a AIDS/diagnóstico , Infecções por Vírus de DNA/diagnóstico , Infecções por HIV/complicações , Reação em Cadeia da Polimerase/métodos , Sangue/virologia , Contagem de Linfócito CD4 , DNA Viral/sangue , Infecções por HIV/imunologia , Hospitais , Humanos , Índia , PrevalênciaRESUMO
This study has evaluated the performance of a rapid immunochromatographic test (ICT) device in detecting antibodies to Dengue virus (DENV) in a tertiary hospital in South India. Sera from hospital attendees, with requests for DENV antibody testing, were tested with the Panbio Dengue Duo Cassette and a reference antibody capture assay for the detection of IgM (Dengue IgM capture ELISA-National Institute of Virology, India) and IgG (Dengue IgG capture ELISA-Panbio Diagnostics Inc., Australia) antibodies. The ICT results were compared with results of antibody capture tests for the detection of the IgM and IgG antibodies, respectively. Accuracy indices for IgM and IgG detection, respectively were -- sensitivity 81.8% and 87.5%, specificity 75.0%, and 66.6%, positive predictive value (PPV) 61.0% and 72.9% and negative predictive value (NPV) 89.6% and 83.9%. The device performs poorly in detection of IgM and IgG antibodies to DENVs and is not recommended for use as a stand-alone diagnostic test.
Assuntos
Anticorpos Antivirais/sangue , Cromatografia de Afinidade/métodos , Vírus da Dengue/imunologia , Dengue/diagnóstico , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Hospitais , Humanos , Imunoensaio/métodos , Índia , Kit de Reagentes para Diagnóstico , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Typing of Herpes simplex virus (HSV) isolates is required to identify the virus isolated in culture. The methods available for this include antigen detection by immunofluorescence (IF) assays and polymerase chain reaction (PCR). This study was undertaken to standardize a molecular method for typing of HSV and compare it with a commercial IF reagent for typing. OBJECTIVES: To compare a molecular method for typing HSV isolates with a monoclonal antibody (MAb) based IF test. STUDY DESIGN: This cross-sectional study utilized four reference strains and 42 HSV isolates obtained from patients between September 1998 and September 2004. These were subjected to testing using an MAb-based IF test and a PCR that detects the polymerase ( pol ) gene of HSV isolates. RESULTS: The observed agreement of the MAb IF assay with the pol PCR was 95.7%. Fifty four point eight percent (23/42) of isolates tested by IF typing were found to be HSV-1, 40.5% (17/42) were HSV-2, and two (4.8%) were untypable using the MAb IF assay. The two untypable isolates were found to be HSV-2 using the pol PCR. In addition, the cost per PCR test for typing is estimated to be around Rs 1,300 (USD 30), whereas the cost per MAb IF test is about Rs 1,500 (USD 35) including all overheads (reagents, instruments, personnel time, and consumables). CONCLUSION: The pol PCR is a cheaper and more easily reproducible method for typing HSV isolates as compared to the IF test. It could replace the IF-based method for routine typing of HSV isolates as availability of PCR machines (thermal cyclers) is now more widespread than fluorescence microscopes in a country like India.