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Biomedical subjects

A K Karim

Publications and source records attributed to A K Karim.

8 recordsLinked to original sources
PubMed1989

The human lens epithelium; morphological and ultrastructural changes associated with steroid therapy.

A distinct disturbance to the structure of the lens epithelium was observed in cataract patients receiving steroid medication. Of those cataract patients receiving steroids, 83% exhibited a reticulated pattern of intercellular clefts compared to 5% in the control group. The reticulated pattern was shown to be due to the presence of gaps between the lateral borders of the epithelial cells by electron microscopy. A significant correlation between steroid therapy and epithelial disruption was demonstrated. The significance of such epithelial disruption to cataract formation is discussed.

Adrenal Cortex Hormones↗
PubMed1987

The human anterior lens capsule: cell density, morphology and mitotic index in normal and cataractous lenses.

The morphology, cell density and mitotic index of human lens epithelial cells were determined according to the region of the opacity as follows: (1) nuclear; (2) posterior subcapsular; (3) cortical; (4) nuclear and posterior subcapsular; (5) cortical and posterior subcapsular. Epithelial abnormalities, consisting of enlarged, polymorphous cells and intercellular clefts, were found in cataractous lenses involving posterior subcapsular and/or cortical opacities. In contrast to the normal pattern of cell density, the cell density of cataractous epithelia in these categories decreased from the central to the peripheral epithelium. This decrease in cell density was due to the presence of swollen cells and intercellular clefts. The central and pre-equatorial mitotic index of cataractous lens epithelia was not significantly different (range 0.002-0.008%) and no correlation was found between cataract type and mitotic index (no information was available for the equatorial region). The low mitotic index observed reflects the mature age range of cataractous lenses and in one normal lens epithelium from a 23-yr-old donor, a higher value of 0.015% was found. The relevance of these epithelial abnormalities to the normal function of the epithelium is discussed.

Adult↗
PubMed1987

The effects of steroids on the human lens epithelium.

A study of anterior capsules from cataractous lenses revealed that there are marked abnormalities in epithelial structure associated with cataract. In certain cases a distinctive reticulated pattern was observed in whole mounts of the anterior capsule and of these a higher number than expected were from patients receiving steroid medication. In tissue culture experiments it was found that the presence of steroids in the growth medium (10 microM prednisolone) adversely affected the growth of human lens epithelial cells. These observations are consistent with the hypothesis that steroid-induced cataracts are the result of effects on anterior lens epithelial cell function.

Adult↗
PubMed1976

Polymorphic acetylation of nitrazepam.

Nitrazepam is metabolized in part by nitro-reduction to an amine followed by acetylation. This acetylation step has been shown to be under the control of the same genetic polymorphism as sulphamethazine (syn: sulphadimidine).

Biotransformation↗