948 resultados para hepatitis A infection
Resumo:
Administration of polyamines into the central nervous system results in tissue damage, possibly through the excitotoxic actions of the NMDA receptor. Direct injection of 100 nmol of spermine into the rat striatum produced a lesion equivalent to approximately 50% of the striatum. Analysis of the DNA in this region revealed the distinct ladder-like pattern of degradation often associated with apoptosis. This DNA fragmentation was confirmed in vivo using terminal deoxynucleotidyl-transferase-mediated biotinylated deoxyuridine triphosphate nick end labelling (TUNEL). The morphology of the TUNEL-positive cells showed marked differences at the needle tract when compared with cells in damaged areas away from the needle tract, suggesting a differential mechanism of cell death in these two regions. The patterns of p53, c-Fos and c-Jun protein expression were determined using immunohistochemistry. The number of p53-immunoreactive cells increased up to 14 h and returned to basal levels by 24 h. c-Fos protein expression transiently increased, peaking at 8 h after injection, c-Jun exhibited a protracted pattern of expression, remaining elevated up to 24 h. p53 protein expression was colocalised with TUNEL staining in areas away from the needle tract, but not in cells at the needle tract, suggesting once again a differential mechanism of cell death. At 14 h, c-Fos and c-Jun were not colocalised with TUNEL staining, suggesting that they are either not involved with the cell death process or that the time course of protein expression and the onset of DNA fragmentation do not overlap. This work represents the first characterisation of processes associated with cell death induced by spermine in vivo.
Resumo:
Rates of cell size increase are an important measure of success during the baculovirus infection process. Batch and fed batch cultures sustain large fluctuations in osmolarity that can affect the measured cell volume if this parameter is not considered during the sizing protocol. Where osmolarity differences between the sizing diluent and the culture broth exist, biased measurements of size are obtained as a result of the cell osmometer response. Spodoptera frugiperda (Sf9) cells are highly sensitive to volume change when subjected to a change in osmolarity. Use of the modified protocol with culture supernatants for sample dilution prior to sizing removed the observed error during measurement.
Resumo:
Hepatitis C virus (HCV) is a major cause of chronic liver disease that may progress to cirrhosis. Antiviral treatment is successful in less than 50% of patients, is costly and causes debilitating side effects. For these reasons, additional therapies to limit the progression of liver disease are urgently required. Steatosis is found in 60% of patients with HCV and is strongly associated with more severe fibrosis. Improvements in biochemical parameters may be seen with weight reduction, however the effects on liver histology have not been investigated. We propose that in patients with chronic HCV and steatosis, obesity contributes to fat in the liver, which results in increased fibrosis and progression to cirrhosis. This study investigated the effect of weight reduction on liver biochemistry and histology in patients with HCV and the success of weight maintenance after an intensive intervention. We examined the effect of a 12 week diet and exercise program where all subjects were seen weekly by the Dietician, with the goal of achieving a 0.5 kg weight loss per week. Biochemistry was monitored monthly and a liver biopsy was performed prior to and 3-6 months after the intervention period. Patients then entered a 12 month weight maintenance program with monthly dietetic review. After 12 weeks there was a mean weight loss of 5.9 ± 3.2 kg and a mean reduction in waist circumference of 9.0 ± 5.0 cm. In 16 of the 19 patients, serum ALT levels fell progressively with weight loss. Mean fasting insulin fell from 16 to 11 mmol/L (p
Resumo:
Vaccines to prevent PV infection, utilising PV L1 virus like particles (VLPs) to induce neutralising antibody, are in clinical trial and show all the characteristics likely to be associated with success. Results warrant global planning for the deployment of VLP vaccines within a decade, as part of a program to prevent cervical cancer. Vaccines designed to treat existing PV infection by inducing therapeutic cellular immunity targeted to PV proteins are at a much earlier stage of development. The wide choice of potential and proposed antigens, routes and mechanisms of delivery, and possible treatment regimens suggest that, to move the field forward, surrogate markers allowing comparison of the relative efficacy of different vaccine approaches are required. These should be based on reduction in load of virus infection, and need to be validated in animal models or in man. (C) 2002 Published by Elsevier Science B.V.
Resumo:
Background: Reports on the effect of HIV-1 infection on healing rates of ulcers are conflicting. Goal: The goal was to determine the etiology and response to treatment of genital ulcer disease (GUD) in relation to HIV-1 infection. Study Design: This was a cohort study of patients with GUD treated with local syndromic management protocols. Results: Among the 587 recruited, the prevalences of infections due to HSV, Treponema pallidum, Chlamydia trachomatis (lymphogranuloma venereum [LGV]), Haemophilus ducreyi, Calymmatobacterium granulomatis, and HIV-1 were 48%, 14%, 11%, 10%, 1%, and 75%, respectively. The prevalence of T pallidum was higher among men (P = 0.03), and an association was seen among HIV-1-seronegatives on univariate and multivariate analyses (P < 0.001; P = 0.01). The prevalence of C trachomatis (LGV) was higher among females (P = 0.004), and an association was seen among HIV-1-seropositives on univariate analysis (P = 0.04). At follow-up, 40/407 (10%) showed a decreased healing tendency, not associated with ulcer etiology or HIV-1 seropositivity. Conclusion: Response to syndromic management of GUD was acceptable and not associated with HIV-1 coinfection.
Resumo:
OBJECTIVE To determine the prevalence, intensity and associated risk factors for infection with Ascaris, hookworms and Trichuris in three tea-growing communities in Assam, India. METHODS Single faecal samples were collected from 328 individuals and subjected to centrifugal floatation and the Kato Katz quantitation technique and prevalence and intensities of infection with each parasite calculated. Associations between parasite prevalence, intensity and host and environmental factors were then made using both univariate and multivariate analysis. RESULTS The overall prevalence of Ascaris was 38% [95% confidence interval (CI): 33, 43], and the individual prevalence of hookworm and Trichuris was 43% (95% CI: 38, 49). The strongest predictors for the intensity of one or more geohelminths using multiple regression (P less than or equal to 0.10) were socioeconomic status, age, household crowding, level of education, religion, use of footwear when outdoors, defecation practices, pig ownership and water source. CONCLUSION A universal blanket treatment with broad-spectrum anthelmintics together with promotion of scholastic and health education and improvements in sanitation is recommended for helminth control in the communities under study.
Resumo:
We determined the prophylactic effect of both the d-mannose-binding lectin ArtinM extracted from the seeds of Artocarpus integrifolia (jackfruit) and its recombinant counterpart during the course of experimental paracoccidioidomycosis induced in BALB/c mice. Four experimental protocols of prophylaxis were employed to evaluate the most protective regimen of ArtinM administration. It was demonstrated that the best effect was obtained by administration of two ArtinM doses on days 10 and 3 before the challenge with Paracoccidioides brasiliensis. By following this protocol, the lungs of mice that received native or recombinant ArtinM exhibited reduced fungal burden and granuloma incidence. In addition, the protocol augmented contents of IL-12, IFN-gamma, TNF-alpha and NO. On the other hand, the control group consisting of untreated infected mice had higher pulmonary levels of IL-4 and IL-10. In conclusion, prophylaxis with ArtinM significantly reproduces the effect of its therapeutic administration, i.e, it confers resistance to P. brasiliensis infection in mouse models by promoting IL-12 production and favours Th1-immunity.
Resumo:
KM+ is a mannose-binding lectin from Artocarpus integrifolia that induces interleukin (IL)-12 production by macrophages and protective T helper I immune response against Leishmania major infection. in this study, we performed experiments to evaluate the therapeutic activity of jackfruit KM+ (jfKM(+)) and its recombinant counterpart (rKM(+)) in experimental paracoccidioidomycosis. To this end, jfKM(+) or rKM(+) was administered to BALB/c mice 10 days after infection with Paracoccidiodes brasiliensis. Thirty days postinfection, lungs from the KM+-treated mice contained significantly fewer colony-forming units and little to no organized granulomas compared to the controls. In addition, lung homogenates from the KM+-treated mice presented higher levels of nitric oxide, IL-12, interferon-gamma, and tumor necrosis factor-a, whereas higher levels of IL-4 and IL-10 were detected in the control group. With mice deficient in IL-12, Toll-like receptor (TLR) 2, TLR4, or TLR adaptor molecule MyD88, we demonstrated that KM+ led to protection against P. brasiliensis infection through IL-12 production, which was dependent on TLR2. These results demonstrated a beneficial effect of KM+ on the severity of P. brasiliensis infection and may expand its potential use as a novel immunotherapeutic molecule.
Resumo:
Autoimmune hepatitis (AIH) is a chronic hepatitis of unknown etiology characterized by continuing hepatocellular necrosis and inflammation that afflicts 100,000 to 200,000 persons in the United States. It is a rare manifestation of systemic sclerosis. Only about nine reports of this association have been previously reported in the literature. Importantly, all cases had the limited clinical form of systemic. The authors describe herein the first report of a patient with diffuse systemic sclerosis who was diagnosed with AIH with positive antimitochondrial antibody and had an excellent response to immunosuppressive drugs. We also briefly review the literature regarding this issue.
Expression of the iron regulatory peptide hepcidin is reduced in patients with chronic liver disease
Resumo:
Disturbances in iron metabolism often accompany liver disease in humans and hepatic iron deposition is a frequent finding. Since the peptide hepcidin, a major regulator of body iron homeostasis, is synthesised in the liver, alterations in hepcidin expression could be responsible for these effects. To investigate this possibility, we studied hepcidin expression in liver biopsies from patients with hepatitis C virus (HCV) infection, non-alcoholic fatty liver disease (NAFLD) and hemochromatosis (HC). Total RNA was extracted from the liver tissue of 24 HCV, 17 NASH and 5 HC patients, and 17 liver transplant donors (controls). The levels of mRNA for hepcidin and several other molecules involved in iron metabolism (DMT1, Dcytb, hephaestin, ferroportin, TfR1, TfR2, HFE and HJV) were examined by ribonuclease protection assay and expressed relative to the housekeeping gene GAPDH. The expression of hepcidin was significantly decreased in HCV and NASH patients relative to control liver (109±16 and 200±44 versus 325±26 respectively; P=0.008 and 0.02). We have previously reported similar findings in patients with HC, and this was confirmed in the current analysis (176±21; P=0.003). In both HCV and NAFLD patients the expression of the iron reductase Dcytb and the transferrin binding regulatory molecule TfR2 was also decreased, while the cellular iron exporter ferroportin showed a significant increase. Levels of the mRNA for the iron oxidase hephaestin were lower in HCV patients alone, while expression of the major transferrin binding molecule TfR1 was decreased only in NAFLD patients. Of particular interest was the finding that the expression of HJV (which is mutated in patients with juvenile HC) was significantly increased in NAFLD patients. No changes were seen in the expression of the iron importer DMT1 or the regulatory molecule HFE. Decreased expression of hepcidin in patients with HCV and NAFLD provides an explanation why iron homeostasis could be perturbed in these disorders. Reduced hepcidin levels would increase intestinal iron absorption and iron release from macrophages, which could contribute to hepatic iron accumulation. This in turn could lead to alterations in the expression of various proteins involved in iron transport and its regulation. Indeed most of the changes in the expression of such molecules observed in this study are consistent with this. However, the mechanisms leading to changes in the expression of hepcidin in these diseases remain to be elucidated.
Resumo:
Major requirements for performance of liver biopsy (LB) are the benefits for the patient and the impossibility of having the same information by less invasive procedures. In the last two decades physicians have faced the difficult task of convincing a patient positive for hepatitis C, with minimal clinical or laboratory alterations to be submitted to LB in order to evaluate the status of the disease for therapeutic management. The characteristics of the needle used for percutaneous LB interferes with the accuracy of diagnosis. In chronic hepatitis C (CHC), validity is achieved with liver fragments about 25mm in length containing more than 10 portal tracts. Morbidity due to LB is mainly related to bleeding but death is very rare. Severe complications are also uncommon, increasing with number of passes and decreasing with experience of operator and ultrasound guidance. Although CHC is a diffuse disease, the various areas of the liver may not be equally affected and sampling errors are possible. Another potential limitation of LB is the discordance between pathologists in its interpretation. To replace LB, many panels of surrogate markers have been described, aiming to identify extent of fibrosis and inflammation. All of them have used LB as their ""gold standard"". Liver biopsy continues to be the most reliable method to evaluate the possibility of therapy for CHC. Universal treatment of all patients with diagnosis of CHC would be ideal. But, there are mainly three drawbacks. Overall efficacy is as low as 50%, side effects are common and may be severe and treatment is prolonged and expensive. The acceptability of the biopsy by the patient is highly dependent on the physician`s conviction of its usefulness.