Biomedical subjects

Marcel G H M Beld

Publications and source records attributed to Marcel G H M Beld.

5 recordsLinked to original sources

PubMed2006

Simplified PCR protocols for INNO-LiPA HBV Genotyping and INNO-LiPA HBV PreCore assays.

BACKGROUND: INNO-LiPA HBV Genotyping (LiPA HBV GT) and INNO-LiPA HBV PreCore (LiPA HBV PC) are commercially available assays for hepatitis B virus (HBV) characterization. These assays are labor-intensive and may be prone to exogenous DNA contamination due to their use of nested PCR amplification procedures and lack of contamination control measures. OBJECTIVE: Standardized, single-round INNO-LiPA PCR amplification protocols incorporating uracil N-glycosylase and automated sample processing by the MagNA Pure LC instrument were evaluated. STUDY DESIGN: HBV standards containing 10,000, 1000, 100, 10, and 0 IU/mL were analyzed to determine the analytical sensitivity and reproducibility of these modified procedures. One hundred clinical serum specimens with viral titers ranging from 390 to 16,900,000 IU/mL were tested by modified LiPA HBV GT, while 34 specimens with viral titers ranging from 378 to 11,600,000 IU/mL were tested by modified LiPA HBV PC. RESULTS: Modified LiPA HBV GT and LiPA HBV PC each yielded analytical sensitivities of 100% at an HBV DNA level of 1000 IU/mL and 90% at a level of 100 IU/mL. Among clinical specimens, success rates for both INNO-LiPA procedures were > or =94%. CONCLUSIONS: Both modified INNO-LiPA procedures were sensitive and reproducible, with improved efficiency and suitability for routine laboratory use.

DNA, Viral↗

PubMed2006

Fourth human parechovirus serotype.

We identified a novel human parechovirus (HPeV) type (K251176-02) from a neonate with fever. Analysis of the complete genome showed K251176-02 to be a new HPeV genotype. Since K251176-02 could not be neutralized with antibodies against known HPeV serotypes 1-3, it should be classified as a fourth HPeV serotype.

Base Sequence↗

PubMed2006

Role of viruses in Kenyan children presenting with acute encephalopathy in a malaria-endemic area.

In malaria-endemic areas, it is difficult to differentiate between cerebral malaria (CM), bacterial meningitis, and viral encephalitis. We examined the cerebrospinal fluid of 49 children who fulfilled the World Health Organization's (WHO) definition of CM and in 47 encephalopathic children, without malaria, looking for viruses with polymerase chain reaction. In the children with CM, four (9%) had evidence of Herpes simplex virus 1 in the cerebrospinal fluid, whereas in the encephalopathy group without malaria, six (12%) were positive. A significant proportion of children who fulfil the WHO clinical definition of CM may have viral encephalitis.

Brain Diseases↗

PubMed2005

No evidence of in vitro and in vivo porcine endogenous retrovirus infection after plasmapheresis through the AMC-bioartificial liver.

BACKGROUND: Currently a number of bioartificial livers (BAL) based on porcine liver cells have been developed as a treatment to bridge acute liver failure patients to orthotopic liver transplantation or liver regeneration. These xenotransplantation related treatments hold the risk of infection of treated patients by porcine endogenous retrovirus (PERV) released from the porcine cells, as in vitro infection experiments and transplantations in immunocompromised mice have shown that PERV is able to infect human cells. The Academic Medical Center (AMC)-BAL, unlike other BALs, is characterized by direct contact between porcine liver cells and human plasma, and might therefore be permissive for PERV transfer. METHODS: Prior to a clinical phase I trial, human plasma perfused through the AMC-BAL was investigated for PERV DNA and RNA. Moreover productive infectivity was analyzed by exposing the plasma to HEK-293 cells that were subsequently tested for PERV DNA, PERV RNA and reverse transcriptase activity. RESULTS: Although PERV DNA was detected in the perfused plasma, no productive infectivity was detected. Consequently fourteen patients were treated with the AMC-BAL and monitored for PERV transmission. Immediately after treatment the plasma of the patients was positive for PERV DNA, most probably due to porcine liver cell lysis. The PERV DNA was cleared within 2 weeks post-treatment and no PERV RNA was detected. No productive infectivity in human embryonic kidney (HEK)-293 cells exposed to plasma of treated patients was detectable. CONCLUSION: To conclude, no release of infective PERV particles from the AMC-BAL was observed. Therefore we consider the AMC-BAL as safe, however careful surveillance of patients will be continued.

Adult↗

PubMed2004

Multicenter evaluation of the VERSANT hepatitis B virus DNA 3.0 assay.

The VERSANT hepatitis B virus (HBV) 3.0 Assay (branched DNA [bDNA]) (referred to herein as VERSANT 3.0) was evaluated at four external sites for analytical sensitivity, specificity, reproducibility, linearity of quantification, and limits of detection. In addition, each of the test evaluation sites provided HBV DNA-positive clinical samples that were previously analyzed by one of three commercially available HBV DNA quantitative tests: Digene Hybrid Capture II HBV DNA Test (Digene); VERSANT HBV DNA 1.0 Assay (bDNA) (VERSANT 1.0); and COBAS AMPLICOR HBV Monitor Test (COBAS AMPLICOR). These samples were reexamined using VERSANT 3.0. The results from these studies showed that VERSANT 3.0 has high specificity (99.3%), excellent reproducibility (between-run coefficient of variation [CV] = 1.6 to 9.4%; within-run CV = 6.5 to 20.7%), and a broad linear range of quantification (2.0 x 10(3) to 1.0 x 10(8) HBV DNA copies/ml) that facilitate the monitoring of HBV DNA levels at diagnosis and throughout the course of treatment. In general, correlation was very good between results obtained from clinical samples analyzed by VERSANT 3.0 and the comparative HBV DNA quantitative assays (VERSANT 1.0, R(2) = 0.900; Digene, R(2) = 0.985; COBAS AMPLICOR, R(2) = 0.771). The greatest differences in comparative quantitation occurred at HBV DNA levels approaching the limits of the dynamic ranges for the comparative assays. The performance characteristics of the new VERSANT 3.0 assay demonstrated that it provides a reliable and robust method for routinely monitoring serum HBV DNA levels in assessing disease activity and determining response to antiviral treatment.

DNA, Viral↗