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Biomedical subjects

B Lippert

Publications and source records attributed to B Lippert.

41 records · Page 3Linked to original sources
PubMedDate not supplied

Sequential neuropathology of dogs treated with vigabatrin, a GABA-transaminase inhibitor.

Vigabatrin (Sabril) is a gamma-aminobutyric acid-transaminase (GABA-T) inhibitor that is effective in the treatment of certain types of drug-resistant or uncontrolled epilepsy but is known to cause microscopic vacuolation (intramyelinic edema) in the brains of treated rats, mice, and dogs. The effects of high oral doses (300 mg/kg/day) of vigabatrin administered orally to Beagle dogs were studied during treatment weeks 1-12 and recovery weeks 13, 14, 16, 20, 24, and 28. Emesis, loose stools, and anorexia and 3 drug-related deaths were observed during the first 4 wk of treatment but were virtually nonexistent thereafter because of adaptation to the drug aided by food supplementation. In more sensitive areas of the brain (columns of the fornix, thalamus, and hypothalamus), microscopic quantitative differences between background vacuolation in controls and drug-related vacuolation in treated dogs could be delineated after 4 wk, generally reached highest levels of severity between 8 and 12 wk, and were reversible upon cessation of dosing. Inhibition of brain GABA-T and elevation of brain GABA were noted after 1 wk of treatment. During the course of treatment vigabatrin ranged between 4-17 nmol/ml (plasma) and 42-1,570 nmol/ml [cerebrospinal fluid (CSF)] while CSF GABA concentrations were 4-32 nmol/ml (treated dogs) and 0.1-0.6 nmol/ml (control dogs). Although the cause of vigabatrin-induced microvacuolation is unknown, the results of the study demonstrated that GABA-T inhibition with subsequent GABA elevation occurred within the first week of treatment and was followed by the onset of detectable microvacuolation several weeks later.

4-Aminobutyrate Transaminase↗
PubMedDate not supplied

[Resistance of isolated cells from squamous cell carcinomas of the oral cavity to cytotoxic drugs].

Human tumor cells from 22 patients with squamous cell carcinomas of the oral cavity were cultivated in vitro and then subjected to sensitivity tests to cytotoxic drugs such as methotrexate, 5-fluorouracil, cisplatin and bleomycin. Tumor cell proliferation showed drug-specific reaction patterns and time-dose-dependent variations. While the effect of methotrexate on cell proliferation was insignificant, 5-fluorouracil caused a growth suppression of 50%. Cisplatin and bleomycin suppressed cell growth by more than 90%.

Antineoplastic Agents↗