Showing papers by "Archana Sharma published in 1989"
TL;DR: The ability to chelate Cu(II) ions is seen to be of the order: purine > purine ribonucleotides, purine nucleoside > pyrimidine ribon nucleotides.
93 citations
TL;DR: Trimethyltin chloride was found to induce cytotoxic damage in vitro in human peripheral blood lymphocytes and endoreduplication, an extremely rare spontaneous event in human lymphocytes, was observed in a few cases at all dose levels.
Abstract: Trimethyltin chloride was found to induce cytotoxic damage in vitro in human peripheral blood lymphocytes. Two concentrations (0.5 μg and 1.0 μg) were added to lymphocytes from male and female subj...
25 citations
TL;DR: The frequency of congenital defects was noted to decline with increasing maternal age, 21–25 years age group had maximum number of malformed babies, whereas cleft palate with/without hare lip had highest frequency during winter.
Abstract: Retrospective study was carried out in 1,15,851 consecutive births in five hospitals, and prospective study of 10,415 consecutive births in one hospital of West Bengal. The overall frequency of congenital defects was 4.42/1000 live births. Incidence of NTD and talipes was predominant in rainy season, whereas cleft palate with/without hare lip had highest frequency during winter. Incidence of these anomalies decreased with increasing birth order. The frequency was noted to decline with increasing maternal age, 21-25 years age group had maximum number of malformed babies. Sex ratio and religion, however, did not have any correlation with the incidence of these malformations. When comparison was done between urban and rural population no statistically significant variation was observed.
24 citations
TL;DR: A reduction of the early higher level of toxicity was noticed following 48 h of treatment and subsequent recovery in aluminium-free nutrient media in experiments carried out with lower concentrations.
22 citations
TL;DR: Two concentrations (0.5 microgram and 1.0 microgram) of trimethyltin chloride were added to lymphocytes of healthy male and female donors of different age groups and cultured at 37 degrees C for 72 h and the range and mean number of sister chromatid exchanges were significantly increased.
14 citations
TL;DR: Cytological studies have been carried out on four different species of Agave, distributed in different parts of India, and clear absence of distinct multiples in the karyotypes rules out the absence of autopolypoloidy.
Abstract: Cytological studies have been carried out on four different species of Agave, distributed in different parts of India. They revealed triploid to hexaploid numbers ranging from 2n=90 to 180. A distinct bimodal karyotype with very long and very short chromosomes in a definite proportion of 5:25 ratio and a constant base number of n=30 chromosomes are the most significant characteristics. However, structural alterations, principally involving the nucleolar chromosomes of both long and short types, have been recorded. Clear absence of distinct multiples in the karyotypes rules out the absence of autopolypoloidy. Total chromosome length and volume do not necessarily represent direct multiplication along with the multiplication of the chromosome number. All these factors suggest the role of structural alterations along with differential degrees of coiling of chromosomes and allopolyploidy rather than autopolyploidy in the evolution of the different taxa.
12 citations
TL;DR: Sterols and diosgenin production was studied by chromatographic and spectrophotometric methods at different phases of callus growth of Dioscorea floribunda using various hormonal regimes.
5 citations
01 Jan 1989
TL;DR: Induction of unscheduled DNA synthesis in the stomach pyloric mucosa of inbred Swiss albino mice and C3H mice was examined in vitro following administration of various combinations of betel quid ingredients to assess cytotoxicity.
Abstract: Induction of unscheduled DNA synthesis (UDS) in the stomach pyloric mucosa of inbred Swiss albino mice and C3H mice was examined in vitro following administration of various combinations of betel quid ingredients in vivo Effect of the quid ingredients on replicative DNA synthesis was studied to assess cytotoxicity Betel leaf, areca nut, lime, tobacco and two popular brands of Indian chewing mixtures induced UDS to a very significant extent While addition of betel leaf reduces the UDS, tobacco significantly increases it Study of replicative DNA synthesis revealed that extracts of areca nut, nut with lime and both the brands of commercial chewing mixtures tested induced replicative DNA synthesis The genotoxic and cytotoxic potential of the test compounds provide quantitative risk factors, especially in the light of their growing use in Asian countries
4 citations
TL;DR: Tertiary butyl hydroquinone was found to be a DNA damage‐inducing agent and also a cytotoxic chemical in vivo in mice.
Abstract: Tertiary butyl hydroquinone (TBHQ)--a phenolic antioxidant, was evaluated by assessing the induction of sister chromatid exchanges (SCEs) in bone marrow metaphase cells of mice. Six concentrations, 0.5, 2, 20, 50, 100, and 200 mg/kg, of TBHQ were injected intraperitoneally. A positive dose-response effect in the SCE frequency was observed using the Cochran-Armitage trend test. Two mg/kg of TBHQ was found to be the minimum effective dose. Study of the cell-cycle kinetics showed a delay in cell cycle induced by the higher concentrations of TBHQ. Thus, TBHQ was found to be a DNA damage-inducing agent and also a cytotoxic chemical in vivo in mice.
3 citations
TL;DR: In meiotic preparations from gonadal cells of male rats the frequency of hypodiploid or hyperdiploid cells did not change significantly, and in situ DNA estimation of bone marrow nuclei, following Feulgen cytophotometry, also did not show any significant difference with gradual age changes.
Abstract: Chromosome analysis of bone marrow cells from 96 sex-matched Rattus norvegicus of 12 different age groups showed a significant increase in hypodiploid cells with ageing. However, in meiotic prepara...
2 citations