Biomedical subjects
Publications and source records attributed to T K Roy.
Differences in age at marriage, fertility and contraceptive use are related to religious background, individual educational level and community level education. In general, the effects of community education are weak compared to individual level of education, but differences exist between Hindus and Roman Catholics.
We have studied the activity of yeast PGK promoter in E. coli at different temperatures using lacZ as the reporter gene. The B-galactosidase activity was found to be less at 42 degrees C than at 30 degrees C. Northern blot analysis showed that the level of lacZ transcript was less in recombinant cells grown at 42 degrees C, whereas plasmid copy number per cell was more as compared to recombinant cells grown at 30 degrees C. Data suggest that the yeast PGK promoter is less active at 42 degrees C and that this activity is regulated at the level of transcription.
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Certain phosphatases have been localized by histochemical techniques in various tissues of a pigeon cestode, Raillietina (Raillietina) johri. Acid phosphatase (AcPase), alkaline phosphatase (AlPase) and adenosine triphosphatase (ATPase) were present in almost all structures: tegument; subtegumental muscles; subtegumental cells; excretory canal; testes; sperm ductules; vas deferens; cirrus sac; cirrus; ovary; receptaculum seminis; vagina; vitelline gland cells; oocytes; uterus; embryonated eggs. AlPase was absent in parenchyma, spermatocytes, spermatids and spermatozoa. AlPase activity was more intense in the tegument of mature gravid proglottides. AcPase and ATPase were visualized in various stages of spermatogenesis of the parasite. ATPase activity was also observed in chromosomes. 5'-nucleotidase (AMPase) activity was restricted to embryonated eggs only. Functional significance of these phosphatases is discussed.
Thiamine pyrophosphatase and nucleoside diphosphatase have been studied histochemically in Raillietina (Raillietina) johri. Thiamine pyrophosphatase activity has been observed in the tegument, subtegumental muscle, subtegumental cells, medullary parenchyma, excretory canal and various reproductive structures like testes, ovary, vas deferens, spermatozoa and vitellaria. Eggs exhibit moderate enzyme activity. Various nucleoside diphosphates have been found to be hydrolyzed by thiamine pyrophosphatase. CaCl2, MgCl2 and MnCl2 each activated the enzyme at a final concentration of 6 mM whereas cysteine, reduced glutathione and PCMB inhibited the enzyme activity at a final concentration of 10 mM, 10 mM and 20 mM, respectively. KCN and NaF had no effect on the enzyme staining at concentration as high as 50 mM and 30 mM, respectively. Possible roles of the enzyme in the parasite have been discussed.
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The intersexuality amongst plant parasitic nematodes has been discussed to be an intermediate stage of sex reversal of male into female. We, hereby, suggest four possible reasons for the sex reversal, this being an intermediate stage - a so-called intersex phase: (1) gene mutation, (2) unusual numerical relationship between autosomes and sex chromosomes during fertilization, (3) effect of female sex hormone secreted by adult females alongwith the mating attractant, and (4) presence or absence of andrgenic hormone in males. The possible effect of female sex hormone on the synthesis of macromolecules which might play a role in sex reversal, is discussed in particular.
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