Effect of glycyrrhizin on lysis of hepatocyte membranes induced by anti-liver cell membrane antibody

Studies were made on why glycyrrhizin injection decreases the plasma aspartate aminotransferase (AST) and alanine aminotransferase activities in patients with chronic hepatitis.¹ For this, rat hepatocytes were isolated, and incubated with antibody raised against rat liver cell membranes, and the effect of glycyrrhizin on their release of transaminase was investigated. Isolated rat hepatocytes released AST on incubation with anti-liver cell antibody in the presence of complement. At this time, their endogenous phospholipase A₂ activity was increased. Cultured hepatocytes also released the transaminase in the presence of venom phospholipase A₂. Glycyrrhizin suppressed the release of transaminase in the presence of either anti-liver cell membrane antibody or phospholipase A₂. These results suggest that antibody treatment raised the phospholipase A₂ activity in liver cell membranes, resulting in release of transaminases, and that glycyrrhizin suppressed this increase in phospholipase A₂ activity and so inhibited the release of transaminase.     

Preferential Localization of Human CD5+ B Cells in the Peritoneal Cavity

In a transgenic mouse model of autoimmune haemolytic anaemia, CD5⁺ B lymphocytes localized in the peritoneal cavity are shown to play an important role in the onset of autoimmune disease. The authors have examined whether CD5⁺ B cells are present in the peritoneal cavity of 12 human individuals with non-invasive gastrointestinal tumours and found that in humans CD5⁺ B cells preferentially lodge in the peritoneal cavity as compared to the peripheral blood and spleen while the numbers of the peritoneal B lymphocytes in humans are much lower than in mice and vary widely between individuals.     

Dose- and Time-Dependent Liquid Sclerosant Effects on Endothelial Cell Death

BACKGROUND: Intravenous sclerotherapy solutions can induce endothelial cell death. OBJECTIVE: The objective was to determine the relationship between sclerosant concentration and minimum contact time required for in endothelial cell death. METHODS: Cultured bovine aortic endothelial cells were exposed to a broad range of concentrations of two liquid sclerosants, polidocanol and sodium tetradecyl sulfate. Fluorescence microscopy was used to study cells using dyes specifically indicating changes in intracellular calcium levels, nitric oxide production, and loss of cell membrane integrity after sclerosant exposure. Fluorescence intensity measurements were used to identify the timing of cell death. RESULTS: Calcium signaling and nitric oxide pathways were activated by the administration of the sclerosants and were followed by cell death. The time to the activation and the cell death was dependent on the concentration of sclerosants. At 0.3% polidocanol or 0.1% sodium tetradecyl sulfate, cell death occurred within 15 minutes. At less than 0.003% polidocanol and at 0.005% sodium tetradecyl sulfate, cells remained alive after 60 minutes. CONCLUSION: Both sclerosants rapidly led to cell death at sufficiently high concentrations. At low sclerosant concentrations, cell viability was maintained beyond the recording time of the experiment. The timing of endothelial cell death is predictable based on sclerosant concentration during exposure.     

The effect of the slope inclination of buccal polished surface of mandibular denture base on food retention

summary The accumulation of food debris in the buccal vestibule can inhibit normal mastication and appears to be a factor that can cause patient discomfort. This study focused on the effect of the slope inclination of the buccal polished surface of the mandibular denture base on the ability to expel test-food particles from the buccal vestibule. It was revealed that an inclination of the slope steeper than 80° markedly inhibits the normal ability to expel foods from the vestibule. It was revealed that the most appropriate inclination of the buccal slope is approximately 60° or 70°. These results could be utilized for constructing a denture prosthesis.     

Accidental transmission of HCV and treatment with interferon

Accidental transmission of contagious pathogens, especially hepatitis C virus (HCV), by needlestick or other means as an occupational hazard for medical staff is of concern. We retrospectively analysed cases of work-related accidental injury with pathogens such as hepatitis B virus (HBV), HCV, syphilis and human immunode?ciency virus (HIV) reported to the centres for disease control at 15 hospitals (total 5776 beds) in the Gunma prefecture, Japan, from December 1990 to August 1993 (24.7 months). There were 416 such cases (16.8 cases/month), with an incidence of 0.2–3.5 accidents per month per hospital. Such accidents occurred in 297 (71.2%) nurses, 98 (23.5%) medical doctors, 13 (3%) laboratory technicians, four (1.0%) hospital maintenance workers, one (0.2%) assistant nurse, one secretary and two others. There were 323 (77.6%) injuries caused by needlestick, 42 (10.1%) from suture needles or surgical knife cuts, 17 (4.1%) from blood splatters from patients into the eyes or mouth, 10 (2.4%) from contact with injured skin and 24 (5.8%) simple skin contacts. Of the pathogens, 60.3% were HCV, 22.6% HBV, 5.8% syphilis, 0.7% HIV and 10.6% were of unknown origin. Four cases (1.6%) of HCV infection were found and treated with one or two courses of interferon therapy, and HCV was subsequently cleared. All four patients were cured with interferon therapy. None of the HBV-injured cases resulted in infection, possibly because of prophylaxis with HB immunoglobulin and HB vaccine. No HIV or syphilis infection was contracted. In summary, chronic HCV infection acquired as an occupational hazard can be cured by appropriate treatment, such as with interferon, after early detection of the infection.