Hepatitis C among child transfusion and adult renal dialysis patients in Indonesia

Hepatitis C virus (HCV) prevalence among high-risk pediatric and adult patients was evaluated. The study included 269 adults and 150 children in a case-control research design. Risk factors of HCV exposure in Indonesia were assessed among adult renal dialysis patients and pediatric patients who received multiple blood transfusions. A high prevalence of anti-HCV was found among the adult renal dialysis patients, measured by second-generation electroimmunoassay tests. Family members of dialysis patients, who served as a comparison group for dialysis patients, were found to have a 9.0% seroprevalence. The prevalence of anti-HCV among pediatric patients with hematological disorders was found to be 39.0%. The comparison group seroprevalence (pediatric patients and family members) was 4.3% among sera available for confirmatory testing. Patients with history of hospitalization (odds ratio [OR] = 7.94, 95% confidence interval [CI]: 4.06-15.51, P = 0.0001), blood transfusion (OR = 6.85, 95% CI: 3.95-11.88, P = 0.0001), circumcision (OR = 2.39, 95% CI: 1.43-3.99, P = 0.0001), or marital partner/family member history of jaundice (OR = 3.62, 95% CI: 1.97-6.62, P = 0.0001) were found to have an increased odds of HCV exposure compared with individuals without similar histories.     

Protein-Derived Acetaminophen-Cysteine Can Be Detected After Repeated Supratherapeutic Ingestion of Acetaminophen in the Absence of Hepatotoxicity

Generation of protein-derived acetaminophen-cysteine (APAP-CYS) is reported after ingestion of large and therapeutic dosages of acetaminophen in healthy and in liver-damaged patients. The incidence of protein-derived APAP-CYS adducts in repeated supratherapeutic dosages of APAP is not known. Methods: for 12 months, a standardized and comprehensive questionnaire was used to interview every consecutive patient at a pain management clinic. Patients found to ingest more than 4 g of APAP per day for a minimum of 14 consecutive days at the time of the encounter were invited to have blood drawn for hepatic transaminases and APAP-CYS adduct levels. Twelve subjects out of 990 interviewees met inclusion criteria. Ten of the 12 had measurable protein-derived APAP-CYS, none had evidence of liver injury. Patients that ingest repeated supratherapeutic amounts of APAP over several weeks may generate APAP-CYS protein adducts in the absence of hepatic injury.     

Infection of Nippostrongylus brasiliensis induces normal increase of basophils in mast cell-deficient Ws/Ws rats with a small deletion at the kinase domain of c-kit

All basophils, mucosal-type mast cells (MMC) and connective tissue-type mast cells (CTMC) are derived from the multipotential hematopoietic stem cell. Mutations at the c-kit locus resulted in deficiency of MMC and CTMC in both mice and rats. To investigate the role of the c-kit receptor tyrosine kinase for production of basophils, we used white spotting/white spotting (Ws/Ws) mutant rats that have a small deletion at the tyrosine kinase domain of the c-kit gene. When Ws/Ws, nude athymic, and normal (+/+) rats were infected with Nippostrongylus brasiliensis (NB), the number of basophils increased greater than 50- fold in the peripheral blood of Ws/Ws and +/+ rats but did not increase in that of nude rats. Blood histamine concentration increased significantly in Ws/Ws and +/+ rats but did not increase in nude rats. Immature basophils increased greater than 10-fold in the bone marrow of Ws/Ws and +/+ rats but did not increase in that of nude rats. Mature and immature basophils that developed after the NB infection were identified by electron microscopy. The present result confirms that T- cell-derived cytokines are indispensable for the augmented production of basophils and suggests that stimulation via the c-kit receptor may not be necessary for the augmented production.     

A bicistronic retrovirus vector containing a picornavirus internal ribosome entry site allows for correction of X-linked CGD by selection for MDR1 expression

Chronic granulomatous disease (CGD) is an inherited hematologic disorder involving failure of phagocytic cell oxidase to produce superoxide (O2-.), resulting in recurrent infections. The success of retrovirus gene therapy for hematopoietic diseases will be limited both by the efficiency of ex vivo transduction of target cells and by the ability of corrected cells to replace uncorrected cells in vivo. Using MFG-based retrovirus vectors containing oxidase genes, we have previously demonstrated in vitro correction of CGD, but transduction rates were low. In the present study we explore a strategy for providing a selective growth advantage to transduced cells, while retaining the single promoter feature of MFG responsible for high virus titer and enhanced protein production. We constructed a bicistronic retrovirus producing a single mRNA encoding both the therapeutic gene for the X-linked form of CGD (X-CGD), gp91phox, and the selectable human multidrug resistance gene, MDR1 linked together by the encephalomyocarditis virus internal ribosome entry site (IRES). As a control we constructed a bicistronic vector with the polio virus IRES element and using the bacterial neomycin resistance gene (neor) as the selective element. In Epstein-Barr virus transformed B (EBV-B) cells from an X-CGD patient, a tissue culture model of CGD, we show correction of the CGD defect and complete normalization of the cell population using either of these vectors and appropriate selection (vincristine for MDR1 and G418 for neor). Using a chemiluminescence assay of O2-. production, populations of cells transduced with either vector demonstrated initial correction levels of from less than 0.1% up to 2.7% of normal EBV-B cell oxidase activity. With either construct, cell growth under appropriate selection enriched the population of transduced cells, resulting in correction of X-CGD EBV-B cells to a level of O2-. production equalling or exceeding that of normal EBV-B cells. These studies show that a therapeutic gene can be linked to a resistance gene by an IRES element, allowing for selective enrichment of cells expressing the therapeutic gene. Furthermore, the use of MDR1 as a selective element in our studies validates an important approach to gene therapy that could allow in vivo selection and is generalizable to a number of therapeutic settings.     

Oral sedation: a primer on anxiolysis for the adult patient

The use of sedatives has established efficacy and safety for managing anxiety regarding dental treatment. This article will provide essential information regarding the pharmacology and therapeutic principles that govern the appropriate use of orally administered sedatives to provide mild sedation (anxiolysis). Dosages and protocols are intended for this purpose, not for providing moderate or deeper sedation levels.     

The genetic basis of immune and autoimmune responses

HLA class I and class II molecules play a major role in the presentation of short, pathogen-derived peptides to T cells, a process that initiates the adaptive cellular and humoral immune responses. However, the factors governing a cell's ability to respond or not to particular peptides are still not completely understood. Taking the example of a viral infection, in tissues infected with a virus, viral particles are taken up by antigen-presenting cells and uncoated. The viral DNA or RNA enters the nucleus, where it replicates. mRNA enters the cytosol and is transcribed into proteins. These proteins are degraded in proteasomes and the resulting peptides (8–10 residues) are loaded onto class I molecules for export to the surface of the cells. In the meantime, the groove of the class II molecules is also preparing to accommodate peptides (12–24 residues) generated by the endocytic protein-processing pathway. The surface of the infected cell then becomes adorned with peptide-loaded human leukocyte antigen (HLA) molecules. CD4⁺ T helper lymphocytes engage class II molecules and elicit responses from B cells, which will ultimately lead to antibody production, whereas CD8⁺ T lymphocytes become cytotoxic T cells. As a consequence, the virus is eliminated from the body. However, certain mysteries and challenges remain. How can, as an exception to this rule, an autoimmune response be the escape from the perfect machinery? This review offers some hypotheses on how to see the problem through to its solution.