Characterization of six tumorsuppressor genes and microsatellite instability in hepatocellular carcinomain southern African blacks

AIM To analyse cumulative loss of heterozygosity (LOH) of chromosomal regions and tumor suppressor genes in hepatocellular carcinomas (HCCs) from 20 southern African blacks. METHODS p53, RB1, BRCA1, BRCA2, WT1 and E cadherin genes were analysed for LOH, and p53 gene was also analysed for the codon 249 mutation, in tumor and adjacent non tumorous liver tissues using molecular techniques and 10 polymorphic microsatellite markers. RESULTS p53 codon 249 mutation was found in 25% of the subjects, as was expected, because many patients were from Mozambique, a country with high aflatoxin B 1 exposure. LOH was found at the RB1, BRCA2 and WT1 loci in 20%(4/*!20) of the HCCs, supporting a possible role of these genes in HCC. No LOH was evident in any of the remaining genes. Reports of mutations of p53 and RB1 genes in combination, described in other populations, were not confirmed in this study. Change in microsatellite repeat number was noted at 9/*!10 microsatellite loci in different HCCs, and changes at two or more loci were detected in 15%(3/*!20) of subjects. CONCLUSION We propose that microsatellite/genomic instability may play a role in the pathogenesis of a subset of HCCs in black Africans.

Integration of hepatitis B virus DNA into chromosomal DNA during acute hepatitis B

AIM： To examine the serum from black African patients with acute hepatitis B to ascertain if integrants of viral DNA can be detected in fragments of cellular DNA leaking from damaged hepatocytes into the circulation. METHODS： DNA was extracted from the sera of five patients with uncomplicated acute hepatitis B and one with fulminant disease. Two subgenomic PCRs designed to amplify the complete genome of HBV were used and the resulting amplicons were cloned and sequenced. RESULTS： HBV and chromosomal DNA were amplified from the sera of all the patients. In one patient with uncomplicated disease, HBV DNA was integrated into host chromosome 7 q11.23 in the WBSCR1 gene. The viral DNA comprised 200 nucleotides covering the S and X genes in opposite orientation, with a 1 169 nucleotide deletion. The right virus/host junction was situated at nucleotide 1 774 in the cohesive overlap region of the viral genome, at a preferred topoisomerase I cleavage motif. The chromosomal DNA was not rearranged. The patient made a full recovery and seroconverted to anti-HBs- and anti-HBe-positivity. Neither HBV nor chromosomal DNA could be amplified from his serum at that time. CONCLUSION： Integration of viral DNA into chromosomal DNA may occur rarely during acute hepatitis B and, with clonal propagation of the integrant, might play a role in hepatocarcinogenesis.

Follow up of infection of chacma baboons with inoculum containing a and non-a genotypes of hepatitis B virus

AIM: To determine whether one genotype (A or non-A genotypes of HBV) predominated over the other during the course of HBV infection.METHODS: Four baboons were inoculated with HBV. DNA was extracted from serum obtained at monthly intervals postinoculation for 52 weeks and HBV DNA was amplified using primers specific for the core region containing an insert characteristic of genotype A (nt 2 354-2 359, numbering from the EcoRI site). The amplicons were cloned into PCRScriptTM and a minimum of 15 clones per time point were sequenced in both directions.RESULTS: Both genotypes persisted for the entire followup period of 52 weeks. Genotype non-A predominated in two baboons and genotype A in one baboon. Neither genotype predominated in the fourth baboon, as shown at a 5 % level of testing.CONCLUSION: No conclusions concerning the dominance of either genotype or the natural progression or replication rates of HBV could be drawn because the pattern of the genotypes found may have been caused by sampling fluctuations at the time of DNA extraction and cloning as a result of the very low viral loads in the baboon sera.

Unremitting diarrhoea in a girl diagnosed anti-N-methyl-D-aspartatereceptor encephalitis:A case report

BACKGROUND Asymptomatic cytomegalovirus(CMV)infection is common in children;in contrast,in children with a weakened immune system,invasive CMV can occur.This is the first case report of a severe manifestation of CMV esophagoenterocolitis in a girl diagnosed with anti-N-methyl-D-aspartate-receptor(antiNMDAR)encephalitis who received only a moderate dose of corticosteroid therapy.CASE SUMMARY A 12-year-old-Thai girl presented with acute behavioural change and headache for 6 d.Electroencephalogram and positivity for NMDAR autoantibodies were compatible with anti-NMDAR encephalitis.Hence,she received pulse methylprednisolone 10 mg/kg per day for 4 d and continued with prednisolone 1.2 mg/kg per day.On day 42 of corticosteroid therapy,she developed unremitting vomiting and diarrhoea.Endoscopy showed multiple ulcers and erythaematous mucosa along the gastrointestinal tract.Tissue CMV viral load and viral-infected cells confirmed CMV esophago-enterocolitis.Therefore,the patient received ganciclovir 5 mg/kg per dose every 12 h for 3 wk and then 5 mg/kg per dose once daily for 3 wk.Unremitting diarrhoea slowly improved from stool output 1-4 L per day to 1-2 L per day after 3 wk of treatment.Pulse methylprednisolone 20 mg/kg for 5 d was initiated and continued with prednisolone 1 mg/kg per day.After this repeated pulse methylprednisolone treatment,surprisingly,diarrhoea subsided.Immunologic work-up was performed to rule out underlying immune deficiency with unremarkable results.CONCLUSION Unremitting diarrhoea from CMV esophago-enterocolitis subsided with antiviral and methylprednisolone therapy,implying the immune and NMDAR dysregulation in anti-NMDAR encephalitis.

Biomarkers are strongly needed in liver transplantation, time to move forward

The European Society for Organ Transplantation(ESOT)has created a consensus platform for evidence-based and best-practice recommendations.At the 2022 ESOT consensus conference,nine topics were chosen for further exploration based on their potential for impact on healthcare,existing research gaps,and incomplete coverage of the topic in current scientific literature(1).Among these topics,molecular biology testing for non-invasive diagnosis of allograft rejection was a focal point,as detailed in the ESOT consensus statement on biomarkers in liver transplantation(LT)(2).We extend our congratulations to the authors of the liver subgroup on their dedicated effort and rigorous approach in translating major unmet clinical needs into four well-defined questions of interest regarding biomarkers for prediction and/or diagnosis of longer-term complications after LT.

Systematic comparison of experimental and human obstructive cholestasis reveals conservation of canonical pathway activation and biomarkers relevant for cholestatic liver disease

Cholelithiasis-induced cholestasis is one of the most common causes of hospitalization due to gastrointestinal disease,yet considerable knowledge gaps exist in the pathogenesis of this disease.This can partially be explained by inadequate characterization of experimental cholestasis models.Here,we compared the transcriptional profile of commonly used mouse models for obstructive cholestasis and benchmarked them to human disease to identify the model(s)best suited for cholelithiasis-induced cholestasis research and to uncover conserved mechanisms involved in human and murine cholestasis.