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Biomedical subjects

Nino Manca

Publications and source records attributed to Nino Manca.

11 recordsLinked to original sources

Influence of viral chronic hepatitis co-infection on plasma drug concentrations and liver transaminase elevations upon therapy switch in HIV-positive patients.

It is still controversial whether viral hepatitis co-infection can influence antiretroviral plasma drug concentrations and whether drug concentrations are correlated with liver enzyme elevations during highly active antiretroviral therapy. An analysis of data from a cohort of 220 human immunodeficiency virus (HIV)-infected patients was conducted. Univariate and multivariate logistic analyses were performed to identify predictors of plasma drug concentrations. The association of transaminase elevation with higher plasma drug concentrations was explored following stratification of patients into HIV monoinfected and hepatitis C virus (HCV) and/or hepatitis B virus (HBV) co-infected groups. Hepatitis co-infections were independently correlated with drug concentrations above the therapeutic cut-offs at Week 1 (P=0.06), Week 4 (P=0.04) and Week 12 (P=0.005). The apparent effect was independent of the possible impact exerted by other variables such as demographics and medication adherence. The incidence of relevant hypertransaminasaemia was low. Patients with hepatitis co-infections had higher rates of transaminase elevation than monoinfected HIV patients; however, risk of transaminase elevation was not associated with drug concentrations. The presence of HCV and/or HBV co-infections correlated with higher plasma drug concentrations, although it did not appear to influence hepatotoxicity risk.

Adult↗

Quantitative analysis of HBsAg, IgM anti-HBc and anti-HBc avidity in acute and chronic hepatitis B.

BACKGROUND AND OBJECTIVES: We evaluated hepatitis B virus (HBV) serological markers by novel, quantitative immunoassays in order to study their behaviours and possible role in the various phases of HBV infection. STUDY DESIGN: The quantitative determination of HBsAg and anti-HBc/IgM by chemiluminescent immunoassays (Abbott Architect) and the calculation of anti-HBc avidity index have been carried out on repository specimens from patients with acute or chronic hepatitis B. RESULTS: In acute hepatitis the levels of HBsAg were generally >10,000 UI/mL and decreased sharply in the recovery phase. In 35 anti-HBe-positive chronic hepatitis cases HBsAg levels were generally lower than 10,000 UI/mL (mean: 2655), whereas in five HBeAg-positive chronic hepatitis patients the mean value was 78,756 UI/mL and 90% of specimens exceeded 10,000 UI/mL. The lowest values (mean: 1029 IU/mL) were found in the seven patients with minimal hepatic damage. IgM anti-HBc antibodies were positive in all acute cases and in 68/207 samples (32.85%) from patients with chronic hepatitis, with significantly lower levels (average sample/cutoff (S/CO) ratio: 2.95 in chronic cases versus 25.96 in acute cases; p<0.005). A S/CO value of 10 for anti-HBc IgM had a 100% negative predictive value and a 99.13% positive predictive value for acute hepatitis B. The study of anti-HBc avidity by an experimental procedure showed that an avidity index (AI) threshold of 0.7 had a good efficacy to discriminate the cases of chronic hepatitis, among whom only 2 specimens out of 193 (1.04%) had an AI<0.7. CONCLUSION: The quantitative determination of HBsAg, anti-HBc/IgM and anti-HBc avidity provides additional information and may be useful in the differential diagnosis of acute and chronic HBV infections and in the follow-up of chronically infected patients.

Acute Disease↗

Evaluation of INNO-LiPA assay for direct detection of mycobacteria in pulmonary and extrapulmonary specimens.

The INNO-LiPA Mycobacteria kit has been developed for detecting mycobacteria in liquid and solid cultures through amplification of the 16S-23S rRNA mycobacterial spacer region and the use of species-specific probes. The aim of this study was to verify the possible direct use of the kit on clinical samples. The study was performed retrospectively on a total of 129 specimens (104 pulmonary and 25 extrapulmonary) and the results were compared to those obtained from culture. For pulmonary specimens, the overall clinical sensitivity of INNO-LiPA Mycobacteria kit was 79.5% and its specificity 84.6%. For extrapulmonary samples, the kit had an overall clinical sensitivity of 71.4%. In both cases no false positive results were found.

Humans↗

Prediction of early and confirmed virological response by genotypic inhibitory quotients for lopinavir in patients naïve for lopinavir with limited exposure to previous protease inhibitors.

OBJECTIVE: To determine the impact of genotypic inhibitory quotient (GIQ) for lopinavir (LPV) in patients failing HAART with limited antiretroviral exposure. DESIGN: Retrospective analysis of a prospective trial. METHODS: Lopinavir GIQ was calculated as the ratio between the mean trough concentration (C(trough)) and the number of protease mutations using eight different HIV drug resistance mutation lists or algorithms. Early (by week 12) and confirmed (up to week 24) virological response (HIV-RNA< 400 copies/mL, ECVR) was used as dependent variable in logistic regression model. RESULTS: Seventy-one of 109 (65%) patients achieved ECVR. At multivariable logistic regression analysis, each mug/mL increase of GIQ was correlated with increasing probability of ECVR as far as the following mutations were computed: multi-protease inhibitor (PI) associated mutations listed by IAS (OR=1.17; 95% CI=0.99-1.39; P=0.058), mutations associated with LPV resistance by ANRS algorithm (OR=1.21; 95% CI=1.02-1.44; P=0.03), major mutations associated with LPV resistance by Stanford database (OR=1.16; 95% CI=1-1.35; P=0.05), and the whole set of mutations associated with LPV resistance in the same database (OR=1.22; 95% CI=1.02-1.46; P=0.03). Using ROC curve method, a specific threshold GIQ was assessed, above which this parameter could predict ECVR with the highest sensitivity (74.6% with GIQ obtained through Stanford LPV mutations) or specificity (89.5% with GIQ obtained through ANRS LPV mutations). CONCLUSIONS: Our results suggest that increasing GIQ can improve virological outcome even in patients with limited exposure to PIs. Further studies are necessary to understand what HIV protease mutations should be considered and whether such mutations should be weighted differently to improve LPV GIQ predictive value.

Adult↗

Bacteria enclosure between silica-coated membranes for the degradation of organic compounds in contaminated water.

A non-conventional technique is proposed for the enclosure of either pure bacterial cultures or entire biocoenoses, for a possible utilization in the treatment of contaminated water. Biological components have been enclosed between polyester membranes coated by silica films consisting of: (a) SiO2 and nitrocellulose, (b) SiO2, ZnS crystals and nitrocellulose, (c) SiO2, TiO2 crystals and nitrocellulose, (d) SiO2, ZnS and TiO2 crystals and nitrocellulose. Morphological, structural and mechanical features of membranes were investigated by means of optical and electron microscopy, mercury porosimetry and wear resistance tests. Degradation kinetics have been finally studied by dipping the entrapped biomass into aqueous solutions of three different model organic compounds (alpha-d-glucose, ethyl alcohol and peptone). Results are very promising: in fact, no metabolic inhibition mechanisms of microorganisms have been evidenced. The porosity of the system allows mass transfer through the membranes, hence bacteria can grow and degrade pollutants. Besides, by this system, cells are constrained, avoiding they to spread across the retainment scaffold.

Bacteria↗

Determination of HCV genotype by direct sequence analysis of quantitative PCR products.

Hepatitis C virus (HCV) genotyping, combined with quantitative evaluation of HCV RNA, may be beneficial for the management of chronic hepatitis C and in the selection of candidates for interferon treatment. In this study, the COBAS AMPLICOR HCV MONITOR test, a commercially available quantitative assay for HCV RNA, was used. Amplification products obtained from HCV-positive cases were subjected to direct sequencing and genotyping based on seven phylogenetically informative regions within the 5'UTR. Results were compared with those obtained by INNO-LiPA assay. Typing results yielded by both methods were in complete accordance for type and subtype assignment. Twenty-nine of 500 specimens (5.8%) were unclassifiable and belonged to samples with a titer of <70.000 IU, as determined by quantitative assay. Despite this limitation, the overall gain in efficiency, the low rate of test failure and a better resolution of mixed genotypes all constitute a considerable advantage of this system over the commercial hybridization technique for routine clinical laboratory use.

5' Untranslated Regions↗

Polymerase chain reaction as a rapid diagnostic tool for therapy of acute retinal necrosis syndrome.

Herpesviruses are involved in the pathogenesis of acute retinal necrosis syndrome (ARN). A rapid and accurate diagnosis of herpetic infections is crucial for prompt administration of a specific antiviral therapy. The purpose of this study was to evaluate a polymerase chain reaction (PCR)-based assay to detect herpesvirus DNA in the aqueous humor of clinical samples from ten patients with uveitis and clinical suspicion of ARN. Samples were assayed for herpes simplex virus type 1-2 (HSV 1-2), varicella zoster virus (VZV) and cytomegalovirus (CMV). Clinical suspicion of ARN was confirmed for four patients. Two patients (one with bilateral ARN) tested PCR-positive for VZV DNA and the other two were positive for HSV 1-2 DNA. CMV DNA was not detected in any of the samples, and no sample was positive for DNA from more than one virus. The remaining patients did not show any evidence of herpesvirus DNA in their aqueous samples. Our findings demonstrate that the use of PCR for detecting herpesvirus DNA in aqueous humor of uveitic subjects may be a valuable tool for early diagnosis of acute retinal necrosis syndrome and for timely administration of a suitable therapy.

Adult↗

Rapid detection and identification of Brachyspira aalborgi from rectal biopsies and faeces of a patient.

This study reports for the first time the detection of Brachyspira aalborgi in faeces and rectal biopsies of a female suffering for 3-4 months of abdominal pain with long-standing mucosal diarrhoea, rectal bleeding and suspected carcinoma of the rectum. After pre-treatment of samples (faeces and biopsies) with a liquid medium (trypticase soy broth-TSB) containing foetal calf serum (FCS, 10%) and spectinomycin and rifampicin (TSB-SR) the first detection of B. aalborgi isolate HBS1 was observed after 48 h in the primary plates of selective blood agar modified medium (BAM) containing spectinomycin and rifampicin (BAM-SR), where growth zones were signalled by a small weakly beta-haemolytic halo. Attempts to subculture spirochaetes in agar media failed. The new HBS1 isolate was only propagated in TSB broth and at electron microscopy it showed 4 endoflagella inserted at each tapered end. The phenotypic characterization of HBS1 demonstrated absence of hippurate hydrolysis, indole production, alpha-galactosidase, alpha- and beta-glucosidase activities in accordance with the B. aalborgi type strain. Rapid identification of B. aalborgi isolate HBS1 was performed directly from faeces and rectal biopsies and subsequently from pure cultures by a genetic method based on 16S DNA restriction fragment length polymorphism (RFLP)-polymerase chain reaction (PCR). The sequence of 16S DNA amplicon of the isolate HBS1 was found 99.2% corresponding to that of the B. aalborgi type strain. Our results encourage further investigations for the development of a suitable selective agar medium for the isolating and cultivating B. aalborgi from human specimens.

Biopsy↗

Detection of HTLV-I tax-rex and pol gene sequences of thymus gland in a large group of patients with myasthenia gravis.

We report in this study the use of polymerase chain reaction (PCR) for the amplification of the genomic DNA, isolated from thymic tissue, using the primers flanking HTLV-I/II tax-rex genes and the sequence method to analyze the HTLV-I pol sequence of 27 Italian patients with myasthenia gravis. These molecular methods showed that 92.5% of patients tested positive for tax gene and 55% for pol genes; 55.5% samples were positive for both the tax gene of HTLV-I/II, and the pol gene of HTLV-I. Histologic investigation of the thymus showed that 15 samples had thymic hyperplasia, 93% tested positive for the tax gene, and 40% tested positive for both the tax and pol genes of HTLV-I. In contrast, 91.6% of thymoma-positive samples were positive for tax gene I/II and 75% positive for both genes, tax and pol type I. The sequence analysis of PCR product for tax and pol genes confirmed that these amplified products were HTLV-I, with minimal variations. Our date suggested that either HTLV-I or part of the virus genome is involved in the etiopathogenesis of myasthenia gravis.

Adult↗