Biomedical subjects
Publications and source records attributed to G Sadasivan.
The clastogenic effects of frusemide were investigated in vitro for 24 and 72 h. A mitodepressive activity was observed at both times. Chromosomal anomalies showed a dose response. There was a propensity for chromatid abnormalities. The chromosome mutational property of the drug is discussed in the light of earlier studies in vivo by the authors.
The chewing of betel leaf with other ingredients is a widespread addiction in India. The chromosome damaging effect was studied in human leukocyte cultures. There was an increase in the frequency of chromatid aberrations when the leaf extract was added to cultures.
The effects on chromosomal aberrations in bone-marrow cells of feeding irradiated wheat to well-fed and malnourished rats were investigated. Rats maintained on low levels of dietary protein (5 per cent) had a higher incidence of breaks and deletions in their bone-marrow chromosomes compared with rats maintained on adequate levels of protein (18 per cient), showing that the level of dietary protein per se can produce structural abnormalities. Feeding of irradiated wheat to rats was associated with increase in the number of polyploid cells in the bone-marrow. The level of protein in the diet did not appear to influence polyploidy.
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Semen from men of proven fertility was compared with that of men with unexplained infertility to determine differences in spermatozoal functions such as hyperactivation and acrosome reaction and spermatozoal motility characteristics. The hyperactivated spermatozoa in both groups could be visualised on the monitor of the Computer Assisted Semen Analyser and they exhibited 'circling', 'thrashing', 'starspin' and 'helical' motility patterns and the mean hyperactivation rates were not significantly different. However, 20% of the men with unexplained infertility did not exhibit hyperactivation compared to only 4% in the fertile group. Furthermore, the semen from infertile men when evaluated for hyperactivation could be categorised into two groups with those having lower hyperactivation (< 10% or < 6% after 4 and 6 h of incubation respectively), forming the first group, and those having a higher hyperactivation rate constituting the second group. In the fertile men such distinct groups were not visible and the percentage hyperactivation ranged from 1 to 16%. No significant differences were observed in the rate of acrosome reaction of fertile and unexplained infertile men. The non-hyperactivated spermatozoa from unexplained infertile men showed a significant increase in path velocity (VAP), curvilinear velocity (VCL) and amplitude of lateral head displacement (ALH) and a decrease in linearity (LIN) and straightness (STR) compared to spermatozoa from fertile men. Furthermore, the hyperactivated spermatozoa from infertile men also showed an increase in progressive velocity (VSL) (only after 2 h of incubation) and LIN and decrease in ALH and beat cross frequency (BCF) compared to spermatozoa from fertile men. The results are discussed in the light of the importance of the above spermatozoal functions and spermatozoal parameters in fertilization.
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