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Biomedical subjects

A Dasgupta

Publications and source records attributed to A Dasgupta.

At least 289 records · Page 16Linked to original sources
PubMed1977

Comparison of vegetative anatomy of Piperales. II. Leaf.

Many characters of leaf (hair, hypodermal cells, palisade layers, intercellular space, distinction between spongy and palisade parenchyma, "palisade ratio", distribution of collenchyma and sclerenchyma, presence or absence of starch grains, calcium oxalate crystals, number, shape and arrangement of bundles of petiole) are useful distinguishing characters. Reduction of palisade layers seems to be the trend of evolution in Piper and Peperomia.

Plants↗
PubMed1977

Studies on heat output from the hand of frostbite subjects.

We studied 12 subjects, who had suffered first- to third-degree frostbite at high altitude during winter, at Delhi, India. At normal sea level pressure there (PB 740 mm Hg) and in a decompression chamber at a simulated altitude of 4085 m, the studies were at both 26 degrees C and 6.8 degrees C. A group of control (non-frostbite) subjects of comparable age were also studied for their heat output at 26 degrees C, PB 740 mm Hg. Heat output from the hands of a group of mountaineers from the sea level was also studied at 2121 m at 25 degrees C and 4485 m at 7 degrees C. The results indicated that the frostbite subjects had a significantly higher heat ouput at PB 740 mm Hg and 26 degrees C than the non-frostbite subjects. When the former were tested at sea level (PB 740 mm Hg) at 6.8 degrees C, the hand heat output showed a marked and significant decrease. On testing them at a simulated altitude of 4085 m at 26 degrees C and at 6.8 degrees C, a very highly significant reduction in hand heat output was observed compared to their initial value at sea level (740 mm Hg) and 26 degrees C. Their hand heat output also showed a very highly significant decrease compared to mountaineers at 4485 m and 7 degrees C.

Adult↗
PubMed1976

Protein synthesis in rabbit reticulocytes. Characteristics of mRNA (AUG codon)-dependent binding of Met-tRNAfMet to 40 S and 80 S ribosomes.

The characteristics of Met-tRNAfMet binding to ribosomes (40 S and 80 S) were studied using a two-stage assay method (Gupta, N.K., Chatterjee, B. and Majumdar, A. (1975) Biochem. Biophys. Res. Commun. 65, 797) and the complexes formed were analyzed either by Millipore filtration or by sucrose density gradient centrifugation. The results are summarized as follows: (a) with both assay methods, Met-tRNAfMet binding to 40 S ribosomes was entirely dependent upon addition of a partially purified mixture of initiation factors and AUG codon; (b) this binding occurred over a wide Mg2+ concentration range; significant binding was observed even at 20 mM Mg2+; (c) upon addition of 60 S ribosomes, a significant part of Met-tRNAfMet bound to 40 S ribosomes was transferred to 80 S complex. This transfer reaction had a sharp Mg2+ optimum around 2 mM. Met-tRNAfMet-80 S-AUG complex thus formed was active in Met-puromycin synthesis; (d) Met-tRNAfMet deacylase present in crude 0.5 M KCl ribosomal wash is a potent inhibitor of the binding reaction as it deacylates Met-tRNAfMet in the Met-tRNAfMet-40 S-AUG complex; (e) glutaraldehyde (0.5%) degrades Met-tRNAfMet-40 S-AUG complex but increases the background binding of Met-tRNAfMet to 40 S ribosomes in the absence of AUG codon; (f) polynucleotides containing uracil and adenosine are strong inhibitors of Met-tRNAfMet binding to 40 S ribosomes. The order of inhibitory activities of the polynucleotides tested was as follows: poly(rU)-poly(rA) (2:1) greater than poly(rU)-poly(rA) (1:1) greater than poly(rU) greater than poly(rA). Other RNAs tested such as poly(rC), poly(rI)-poly(rC) and phi6 bacteriophage RNA (double-stranded) were without significant effects on the Met-tRNAfMet-binding reaction.

Animals↗
PubMed1976

Effect of the extracts from Aristolochia indica Linn. on interception in female mice.

The crude petroleum ether, chloroform and alcoholic extracts from the roots of Aristolochia indica (Linn.) showed 100% interceptive activity in mature female mice at the single dose of 100 mg/kg body wt. The follow-up studies with the chloroform extract showed the most significant effect in the basic part and two acidic fractions at the single dose levels of 50 mg/kg body wt. No toxic effect was observed at the dose levels used.

Abortifacient Agents↗
PubMed1976

An evaluation of the immune state in leprosy.

An evaluation of the immune state in leprosy was done by the application of a system of graft-versus-host reaction. Peripheral blood lymphocytes obtained from patients with different forms of leprosy and from normal healthy individuals were injected intravenously into the irradiated mice. The rate of blast transformation of the donor cells was measured by the radio-active thymidine uptake. The number of cells labelled with tritiated-thymidine was much higher in the normal individuals and patients with tuberculoid leprosy than in the patients with lepromatous leprosy with the borderline group placed in between the two. However, following successful treatment with DDS, an increased responsiveness and active DNA synthesis could be observed in the previously less responsive lepromatous lymphocytes.

Adult↗
PubMed1975

Histocompatibility antigens (HL-A) in leprosy.

HL-A antigens of 70 leprosy patients and 40 normal healthy individuals were determined by the standard microlymphocytotoxicity test. Both lepromatous and non-lepromatous leprosy patients were tested for the presence of 11 HL-A antigens, and the frequency of each specificity was compared with that in a normal population of the same ethnic group. Although the statistical significance of HL-A8 specificity was found to be marginal in lepromatous leprosy patients, when using ordinary 2 times 2 statistics, there did seem to be a decreased frequency of HL-A9 among the non-lepromatous type. Other antigens tested did not reveal any significant differences between the two groups of subjects.

Adult↗