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Biomedical subjects

M Lande

Publications and source records attributed to M Lande.

15 recordsLinked to original sources
PubMed1999

Decreased capacity for debrisoquine metabolism among black Tanzanians: analyses of the CYP2D6 genotype and phenotype.

The cytochrome P450 2D6 (CYP2D6) genotypes and phenotypes of 106 unrelated, healthy black Tanzanians of Bantu origin were investigated. The results revealed a population with a generally decreased capacity to metabolize the CYP2D6 substrate debrisoquine with 59% of the Tanzanian extensive metabolisers having debrisoquine metabolic ratios (MRs) > 1 versus 20% in Caucasians. This decrease in metabolic capacity was not fully explained by the partially or fully detrimental CYP2D6 gene mutations analysed for in this study. As many as 7% poor metabolizers of debrisoquine were identified but none was homozygous for defective CYP2D6 alleles. The majority among the group of poor metabolizers had relatively low metabolic ratios. The mutational profile indicated a closer association of the Tanzanian CYP2D locus to that of Zimbabweans rather than to that of Ethiopians. The defective alleles CYP2D6*3, *4, *5 and *6 were found at low frequencies (0%, 1%, 6%, 0%, respectively), whereas the CYP2D6*17 allele causing an enzyme with altered specificity was common (allele frequency = 17%). It is concluded that the CYP2D6 genotype in the Tanzanian Bantu population is different from that of other African populations examined to date and that further studies are required to explain the generally lower capacity to metabolize CYP2D6 substrates.

Base Sequence↗
PubMed1986

Collagens of the retinal microvascular basement membrane and of retinal microvascular cells in vitro.

We have analysed the collagens present in vascular basement membranes isolated from bovine retinal and cerebral microvessels and bovine renal glomeruli, and from the non-vascular basement membrane of bovine lens capsule. These are compared with the collagens produced by cultured bovine retinal microvascular pericytes and lens epithelial cells, and by canine retinal microvascular endothelial cells, in vitro. Biochemical and immunocytochemical analyses indicate that all of the vascular basement membrane preparations have an identical collagenous composition, consisting of the same polypeptides present in lens capsule (primarily type IV collagen), together with other polypeptides that are identified as type I, and a small amount of type III collagen. Identification of the latter is based on two-dimensional gel electrophoresis in the presence and absence of a reducing agent. Immunocytochemical studies, however, demonstrate type I, type IV and some type V collagen in the basement membranes of the isolated microvessels. The cultured microvascular cells produce predominantly type I collagen molecules, but they also produce other collagen peptides that appear to be type IV, and, at least in some experiments, small amounts of type III collagen. The biochemical identification of collagens type I and IV is confirmed by immunocytochemistry. However, results with anti-type I collagen and procollagen antibodies in cultured pericytes vary with antibodies from different sources. The quantities of the type IV peptides produced by the cultured cells also vary in different experiments.

Amino Acids↗
PubMed1976

Retention of mRNA on the endoplasmic reticulum membranes after in vivo disassembly of polysomes by an inhibitor of initiation.

Membrane-bound ribosomes and messenger RNA remained associated with the microsomal membranes of human fibroblasts after cultures were treated with Verrucarin A, an inhibitor of initiation which led to extensive run-off of ribosomes from polysomal structures. When a membrane fraction from Verrucarin-treated cells containing such inactive ribosomes and mRNA was suspended in a medium of high salt concentration, extensive release of ribosomal subunits occurred without the need for puromycin. The mRNA nevertheless remained associated with the membranes. These results add support to the conclusion that, in human fibroblasts, mRNA is bound directly to ER membranes, independently of the ribosomes and nascent polypeptide chains.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Trial of analgesia by acupuncture].

The clinical trial involved 31 cases, 10 in stomatology. Acupuncture may produce analgesia after simple premedication. Of 21 abdominal operations, in 5 completion of effect using local infiltration of a few millilitres of lignocaine or intravenous pentazocine was required. In 7, general anaesthesia was required to complete the operation. All patients not receiving supplementary general anaesthesia were able to eat normally as soon as they were back in bed, passed flactus the same day and had a bowel movement the next day. Ten stomatological operations may be considered to be successful. Further pursual of these trials is justified.

Abdomen↗