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Biomedical subjects

A Chatterjee

Publications and source records attributed to A Chatterjee.

At least 343 records · Page 19Linked to original sources
PubMed1978

Interrelationship of tryptophan pyrrolase with tyrosinase in melanogenesis of Bufo melanostictus.

Tryptophan pyrrolase, a microsomal enzyme responsible for the break-down of tryptophan, has been detected in Bufo melanostictus. The enzyme has been found to be deactivated under influence of antivitiligo drug psoralene and activated by hydroquinone, an inhibitor of tyrosinase. Tryptophan pyrrolase has been found to have an antagonistic relationship with tyrosinase in Bufo melanostictus. The implication of the results has been discussed in relation to melanogenesis in vitiligo.

Animals↗
PubMed1978

Pregnant mare's serum gonadotropin: V. Indomethacin or cortisone and the reversal of antifertility efficacy of pregnant mare's serum gonadotropin.

Pregnant mare's serum gonadotropin (PMSG) of 10 IU on day 5 of pregnancy induced luteal demise and consequently an absolute resorption of fetuses and placentae resulted on day 16 of pregnancy. Simultaneous regimen of PMSG and indomethacin or cortisone was found to be consistently effective in preventing the luteolytic effect of PMSG. The growth of the fetuses, placentae as well as corpora lutea was found to be parallel to controls. Similarly, shortening of the duration of pseudopregnancy to 10--12 days in the bilaterally hysterectomized rat by PMSG and its retaining the normal duration of 18--20 days in the presence of indomethacin tempt us to propose that the PMSG-induced luteolysis is possibly reflected through the release of prostaglandin at the ovarian level.

Animals↗
PubMed1978

The possible mode of action of prostaglandins: XIV. Evidence of an involvement of progesterone in the initiation of prostaglandin F2a-induced premature labor in rats.

Prostaglandin F2a (PGF2a) at a dose of 2 mg/kg (sc) on day 18 of pregnancy induced premature emptying of gravid uteri by day 21 in the rat. Bilateral spaying or luteectomy on day 18 of pregnancy induced a refractoriness to respond to the abortifacient action of PGF2a. Injection of progesterone in the spayed or luteectomized pregnant rats, however, restored the sensitivity of the surgically manipulated animals to PGF2a. Premature parturition resulted in all of the animals so far tested. The importance of progesterone in terms of the abortifacient action of PGF2a is discussed.

Animals↗
PubMed1978

Oral rehydration in infantile diarrhoea. Controlled trial of a low sodium glucose electrolyte solution.

The paper describes the first controlled trial of an oral glucose electrolyte solution designed on the basis of the optimum pathophysiological needs for rehydration in infantile diarrahoea. The solution, having a sodium concentration of 50 mmol/l, was tried in a group of 20 infants with moderate to severe dehydration due to acute diarrhoea and was compared with a matched group of 19 infants predominantly under 2 years of age taking a 'standard' oral solution with a sodium concentration of 90 mmol/l. They could be hydrated as well with a low sodium oral solution alone as with the standard solution. Intravenous fluid was not required in either group. The group treated with the high soldium 'standard' solution appeared to develop hypernatraemia and/or periorbital oedema more frequently than the other group. Also, the low sodium solution eliminated the need for additional free water orally.

Child, Preschool↗
PubMed1978

Pregnant mare's serum gonadotropin. IV. Induction of premature labor by pregnant mare's serum gonadotropin and its prevention by using clomiphene or indomethacin.

The administration of pregnant mare's serum gonadotropin (PMSG), 30 IU on day 18 of pregnancy, resulted in premature labor in rats. However, this abortifacient efficacy of PMSG was not demonstrable when a simultaneous injection of progesterone, clomiphene, or indomethacin was scheduled, thus suggesting that the action of PMSG is medicated by the estrogen-stimulated release of prostaglandin. The termination of pseudopregnancy in bilaterally hysterectomized rats by PMSG and its reversal by indomethacin revealed that the inhibition of luteal function by PMSG does not require the presence of a uterus.

Abortifacient Agents↗
PubMed1977

Evaluation of a sucrose/electrolyte solution for oral rehydration in acute infantile diarrhoea.

An oral sucrose/electrolyte solution brought about complete hydration in 19 out of 20 consecutive children with a median age of 1 year with moderate to severe dehydration due to acute diarrhoea (1 child did not respond and needed intravenous therapy). Vomiting, abdominal distension, and appearance of sugar in the stools during oral hydration did not interfere with its success. A satisfactory response was shown by weight gain (mean +/- S.E. = 9-2 +/- 0-6%), restoration of plasma-bicarbonate to normal levels, falls in the haematocrit values and in the plasma specific gravity, and complete clinical recovery. Disaccharidases in jejunal mucosal biopsy specimens in the acute phase showed reduced lactase in 75% and reduced sucrase in 18%; maltase levels were adequate. Except for the child who did not respond, all showed a satisfactory rise of blood-sugar after sucrose and glucose tolerance tests. Sucrose is cheap and easily obtained; its use instead of glucose in electrolyte solutions would be a considerable gain.

Acute Disease↗
PubMed1977

Response of cultured mammalian cells to accelerated krypton particles.

One of the more interesting observations made in early studies with heavy ions is that the cross-section of the radiosensitive area in mammalian cells increases with LET of HZE particles. It is not certain, however, whether this radiosensitive area is limited to the nuclear area of cells. The successful acceleration of krypton ions to 8.5 MeV/amu at the HILAC Lawrence Berkeley Laboratory, has provided an opportunity to gain more information on this question. Cultured human kidney cells (T-1), growing in exponential phase, were exposed to 3 MeV/amu krypton particles and their colony-forming ability studied. The survival curve was found to be exponential with a mean lethal dose D0=720 rad. A calculation of the cross-section of the radio-sensitive area from the data obtained gives a value of about 145 micrometers2. Present results suggest that the inactivation cross-section stays about the same for heavy ions that have LET greater than 20,000 MeV cm2 g-1, that the nucleus is the only sensitive site for high LET radiation and that a single hit of a heavy ion with very high LET in the nuclear region of the cell can lead to lethal effects. Such particles are therefore extremely dangerous to proliferating living cells.

Cell Line↗
PubMed1977

Pregnant mare's serum gonadotropin. III. Hemispaying and the reversal of the antifertility faculty of pregnant mare's serum gonadotropin.

A single injection of 10 IU of pregnant mare's serum gonadotropin (PMSG) on day 5 of pregancy caused wastage of the fetoplacental unit by day 16 of pregnancy. Semispaying, which seems to subtract approximately 50% of the ovarian steroid contribution, at 24, 48, and 72 hours following the PMSG schedule prevented the antifertility faculty of the hormone preparation. However, hemicastration at 96 hours following the gonadotropin regimen was found to be ineffective, and 100% of the test animals showed complete termination of pregnancy. Experimental data collectively tempt us to propose that an estrogen excess, particularly of follicular origin in both ovaries, is essential for more than 72 hours following gonadotropin sensitization before the antifertility faculty of PMSG can be demonstrated.

Animals↗