Cytogenetical effects of sonication in mice and their modulations by actinomycin D and a homeopathic drug, Arnica 30.

Experiments were designed to examine if Actinomycin D, an antibiotic, and Amica 30, a homeopathic drug used against shock and injury, can ameliorate cytogenetic damage induced by single or multiple exposures to ultrasonication. Separate sets of healthy mice were directly exposed to sonication for two minutes either once or they received multiple exposures at an interval of 20 days. The mice were then assessed at different intervals, against suitable controls, using parameters like chromosome aberrations (CA), mitotic index (MI), sperm head anomaly (SHA) and micronucleated erythrocytes (MNE). Separate groups of sonicated mice were either orally administered with Arnica 30 (alcohol 30 in control) or injected intramuscularly with Actinomycin-D (AMD). Elevated frequencies of CA, MI, MNE and SHA were noted in sonicated series. AMD had genotoxic effects of its own and also had additive effects on sonication induced genotoxicity. Sonicated mice fed with Arnica 30 showed appreciably reduced genotoxicity as against alcohol 30 and distilled water fed controls, thereby showing ameliorating effect which may have human application.

Identification of human proteins using the linguist's tools.

The symbolic sequences of the exons that make human proteins are subjected to methods of statistical linguistics. The ideas developed for the natural languages by G. K. Zipf, when applied to these sequences, show significant promise. In particular, we argue, the Zipf's exponent differentiates, and hence, identifies disparate human sequences.

Chromosome banding studies in an Indian mullet: evidence of structural rearrangements from NOR locations.

C-, G- and NOR bands have been studied in the female sex of Rhinomugil corsula. (Mugilidae, Pisces) by deploying the conventional methodologies with suitable modifications of minor nature. The diploid metaphase complements contained 48 acrocentric chromosomes. The localization of C-band heterochromatin was found to be mostly at or near the centromeric regions of the acrocentric chromosomes. The G-type bands were not so well defined, but some of the G-banded chromosomes also contained C-bands. Interestingly, silver-positive NORs were found at the telomeric ends of five acrocentric chromosomes, including one homologous pair having NORs in both chromatids, while one chromosome showed NORs in both of its chromatids and the other two had only one NOR localized at one of its chromatids. This would suggest that one homologue of the second pair of NOR-bearing chromosomes possibly underwent a chromatid exchange with a non-NOR bearing chromosome. This is quite a unique situation not reported earlier in any species of fish., though some other form of NOR-polymorphism/heteromorphism has rarely been reported. Therefore, further exploration in natural populations of this species to examine the other sex and to verify if there also exists other chromosomally polymorphic races (in respect of NOR-polymorphism) of this species, would be rewarding.

Surveillance of mercury content in edible fish.

Samples of estuarine/sea fish and prawn purchased from different markets in and around Calcutta were analysed for mercury content in the edible portions by cold vapour AAS. The contents varied widely from 4.5 to 42.4 ppb. The internationally regulatory fixed levels for mercury in fish (of 1.0 and 0.5 ppm) appear to be too high in view of our findings and the acceptable weekly intake of mercury of 0.005 mg/kg body weight. It is suggested that the statutory permitted level of mercury in fish be reduced drastically from 500 to 50 ppb.