Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0019163 (hepatitis B)
 38,309 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tests for both hepatitis B surface antigen (HBsAg) and hepatitis e antigen (HBeAg) were carried out on wild-caught and laboratory-colonized bedbugs (Cimex lectularius L.), the latter after hepatitis B virus (HBV)-positive blood-meals. Positivity for both antigens was interpreted as an indication of HBV infectivity. Of 22 pools in which were tested 211 bugs collected in the northern Transvaal, 18 were HBsAg-positive and 17 HBeAg-positive, with estimated infection rates of 156,7 and 137,7 per 1000 bugs respectively. Passage of HBV in bugs, allowing an extrinsic incubation period of 57-69 days, resulted in 19 out of 25 bugs being positive for HBsAg after the first passage; only a small number of these were positive for HBeAg. After the second passage all bugs tested were HBsAg-negative, showing that the virus had disappeared. Tests on the salivary glands and carcass of each bug at intervals up to 31 days after an infective meal showed a positivity rate of 98% (HBsAg) and 17% (HBeAg) for carcasses and 20% (HBsAg) and 0% (HBeAg) for salivary glands. Attempts to detect HBV particles in the salivary glands by electron microscopy failed. Bugs were shown to continue to excrete HBsAg in their faeces up to the 42nd day, and both HBsAg and HBeAg together up to the 30th day. HBsAg particles were only detected by electron microscopy in faeces harvested on the 10th day. The results as a whole indicate that no biological multiplication of virus occurs in C. lectularius but that mechanical transmission from insects to man could occur by: (i) contamination of a person when crushing infective bugs; (ii) contamination from infected faeces; and (iii) infection by bite due to regurgitation or interrupted feeding.
 ...
PMID:The mechanical transmission of hepatitis B virus by the common bedbug (Cimex lectularius L.) in South Africa. 684 70

Many cell types efficiently present an epitope of the hepatitis B surface Ag (HBsAg) to murine class I-restricted CTL following an in vitro pulse with native 22-nm HBsAg particles. Processing of exogenous HBsAg particles required its cytochalasin B-insensitive uptake and acid proteolysis in an endocytic compartment, was insensitive to brefeldin A and cycloheximide, and did not involve regurgitation of antigenic peptides. In contrast, after an in vitro pulse of cells with exogenous, heat-denatured 1-micron HBsAg aggregates, only macrophages (but not other cell types tested) presented the Ld-restricted HBsAg epitope efficiently to CTL. Processing of exogenous HBsAg aggregates required its cytochalasin B-sensitive uptake, was insensitive to brefeldin A, and involved regurgitation of antigenic peptides. Processing of the two different, exogenous HBsAg preparations for class I-restricted epitope presentation thus involved alternative pathways: an "endocytic pathway" for native 22-nm particles, and a "phagocytic pathway" for denatured 1-microns aggregates. Both HBsAg preparations displayed different immunogenicity for class I-restricted CTL in vivo when delivered without adjuvants: native HBsAg particles were of high immunogenicity, and denatured HBsAg aggregates were of low immunogenicity. Class I-restricted CTL are thus primed in vivo after "endocytic processing" of native HBsAg particles as well as "phagocytic processing" of denatured HBsAg aggregates.
 ...
PMID:Processing of exogenous heat-aggregated (denatured) and particulate (native) hepatitis B surface antigen for class I-restricted epitope presentation. 759 67

Percutaneous transhepatic biliary drainage (PTBD) is safe treatment for biliary decompression given certain indications. However, this is temporary until definitive drainage is established. We report on a 76-year-old lady with recurrent pyogenic cholangitis and PTBD catheter fracture. She had hepatitis B virus-related Child-Pugh class A liver cirrhosis, hypothyroidism, hyperlipidaemia, and previous atrial fibrillation with a background of mild mitral, tricuspid and aortic valvular regurgitation. She had history of laparoscopic cholecystectomy in the past. She was deemed to be a high operative risk and declined hepatic resection. She had undergone multiple endoscopic and percutaneous biliary interventions to control sepsis and stone burden. A bilateral PTBD catheter was left in situ with plans for 3-monthly change. However, she defaulted follow-up and presented 11 months later with complaints of pain over the drain site and inability to flush the right catheter. Abdominal X-ray and computed tomography scans detected right catheter fracture at two places, making three fragments. She underwent percutaneous removal of the proximal fragment by an interventional radiology team. A temporary 4 Fr catheter was inserted to maintain biliary access. Endoscopic removal of the intra-biliary fragments was done the next day. Complete removal was confirmed on fluoroscopy. Finally, the 4 Fr catheter was replaced by a new 12 Fr catheter. The patient was discharged well.
 ...
PMID:Percutaneous transhepatic biliary drainage catheter fracture: A case report. 3021 51