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Biomedical subjects

A K Ray

Publications and source records attributed to A K Ray.

At least 73 records · Page 4Linked to original sources
PubMed1987

Nuclear activation by thyroid hormone in liver of Singi fish: changes in different ion-specific adenosine triphosphatases activities.

Various ion-dependent (Na+K+, Ca++ and Mg++) ATPases activities in liver cell nuclear membrane have been determined after a single injection of different doses (0.01, 0.025, 0.05, 0.1, 0.25, 0.5, 1, 2 and 4 micrograms/g) of L-triiodothyronine (T3) in Singi fish, Heteropneustes fossilis Bloch. Administration of T3 at a minimum effective dose of 0.05 micrograms upto 4 micrograms/g induced a rise (14 to 43% over control value) in the Na+K+-ATPase activity in a dose-dependent fashion maximum upto 1 microgram/g dose, whereas Ca++-ATPase showed a dose-dependent increase (20 to 43% over control) with 0.25-1 microgram/g of T3, although the increase in the respective enzyme activity was maintained upto 4 micrograms/g of T3 dose. Mg++-ATPase activity in liver cell nuclear membrane was found to be increased at 1 microgram-4 micrograms/g of T3 dose, showing a similar magnitude of increase (7% over the control value) with these doses of T3. Other doses of T3 (0.01 and 0.025 micrograms/g) were ineffective in altering the different ion-specific ATPase activity. Treatment of Singi fish with thiourea (1 mg/ml) for 30 days caused a significant fall in Na+K+, Ca++ and Mg++-ATPase activities upto 21%, 17% and 5%, respectively, below the euthyroid control level. A single injection of T3 at the dose of 1 microgram/g in the hypothyroid fish raised the Na+K+ and Ca++-ATPase activities to about 36% over the control value, and the Mg++-ATPase activity was restored to only the control level. Thus a dose-dependent nuclear effect of T3 is evident from the present investigation.

Adenosine Triphosphatases↗
PubMed1987

Induction of hepatic mitochondrial alpha-glycerophosphate dehydrogenase by L-triiodothyronine in Singi fish (Heteropneustes fossilis Bloch).

A single injection of L-triiodothyronine (T3) in different doses (0.25, 0.5, 5, 20 and 50 micrograms/g) increased the hepatic mitochondrial cytochrome-linked alpha-glycerophosphate dehydrogenase (alpha-GPD) activity and mitochondrial protein content of Singi fish, as observed on the 3rd day. A non-linear dose-response relationship with respect to enzyme activity was observed with different doses of T3. A low dose of 0.1 micrograms of T3 per g failed to cause any change in alpha-GPD activity and mitochondrial protein content of the liver. The enhancement of alpha-GPD activity over the control level with a low and a high dose of T3, viz., 0.5 and 5 micrograms/g, was followed from the 1st to the 7th day, when it was found that enzyme activity reached the maximum level on the 3rd day and then gradually declined to the control value on the 7th day. The percentage increase in enzyme activity with 5 micrograms/g was higher than that with 0.5 microgram/g from the 2nd to 5th day. Compared to the control, these two doses of T3 caused an increase in alpha-GPD activity from the 1st to the 6th day. Cycloheximide inhibited the T3-induced increase in alpha-GPD activity, mitochondrial and total protein content of liver. Immersion of Singi fishes in thiourea-containing (1 mg/ml) medium for 30 days showed a fall in hepatic alpha-GPD activity in comparison to the euthyroid control. A single injection of T3 (0.5 microgram/g) to the hypothyroid fish recovered alpha-GPD activity to more than the euthyroid control level. An increase in mitochondrial protein content in the T3-injected hypothyroid fish has been observed. DNA content of the fish liver remained unchanged in every experimental condition. The results thus showed the significant responsiveness of the fish liver to thyroid hormone.

Animals↗
PubMed1986

Thyroid hormone-induced changes in different ion-specific adenosine triphosphatase activities in liver of Singi fish Heteropneustes fossilis (Bloch).

A single injection of different doses of T3 (0.5, 5, 20, and 50 micrograms/g) to Singi fish caused an increase in Na+K+-ATPase activity in crude liver homogenate in a dose-dependent non-linear fashion on the 3rd d. Ca++- and Mg++-ATPase activity increased only with 20 and 50 micrograms/g of T3. Lowering the dose of T3 to 0.1 microgram and 0.25 microgram/g in a single injection had not effect on these enzyme activities. TETRAC (1, 2, and 4 micrograms/g) and TRIAC (2 and 4 micrograms/g) in a single injection enhanced the activities of Na+K+-ATPase, but Ca++- and Mg++-ATPase activities remained unchanged on the 3rd d. Immersion of Singi fish in thiourea-containing medium (1 mg/ml) for 30 d caused reduction in Na+K+-ATPase activity, but Ca++- and Mg++-ATPase activity remained unaltered. The reduced level of Na+K+-ATPase activity in the thiourea-treated hypothyroid fish was recovered and even brought above the control level by a single injection of T3 at the dose of 0.5 microgram/g. Differential sensitivity of various ion-specific ATPases to T3 in liver of Singi fish is thus documented.

Animals↗
PubMed1986

Functional scanning electron microscopical observations on the oral roof in an air-breathing teleost, Clarias batrachus (LINN.).

Scanning Electron Microscopical (SEM) as well as light microscopical features of the oral roof including barbels of the air-breathing teleost, Clarias batrachus (LINN.) have been described in relation to its feeding habit. 3 distinct types of taste buds have been recorded for the first time in the barbels, lip, and in and around the teeth bearing suprapharyngeal teeth pad of the fish studied. The taste buds in the barbels and lip are elevated over the epithelium and confer wart like appearance which probably help in mechanoreception in addition to chemoreception. The taste buds in the suprapharyngeal teeth pad slightly rise above the epithelium whereas those in the borders of it do not. They also possess numerous minute papillae in the gustatory pores. These taste buds seem to act as chemoreceptors. SEM and light microscopical observations on the structure and distribution of taste buds in the oral roof clearly reveal that the fish is purely a taste-feeder and scans and gropes the food materials from the bottom of the pond.

Animals↗
PubMed1984

Demography of the Juang tribal population of Orissa.

Demographic analysis of genealogical data collected in 1954 for 23 Juang villages was undertaken employing indirect estimation techniques and computer projection methodology. Results indicated that this group did not feature the historically high fertility levels associated with Indian tribal groups, although fertility was higher than previously reported for the Juang. The population did feature a mortality differential, with worse mortality conditions than the Indian national population at this time. Reversed sexual mortality differentials, common in South Asian populations, were also present for the Juang. Computer projection investigation revealed a steadily growing population, in contrast to some Indian tribal groups faced with extinction.

Adolescent↗
PubMed1984

Acclimatory changes in protein and nucleic acid contents of liver, muscle, and ovary of Singi fish (Heteropneustes fossilis Bloch) of two phases of reproductive cycle at different temperatures.

The variation of environmental temperature has significant effect on the metabolism of liver, muscle, and ovary of female Singi fish (non-vitellogenic and vitellogenic). Acclimation of Singi fish at 15, 25, and 30 degrees C for 30 d resulted in reduction of hepatosomatic index with the rise of temperature. The protein content of liver increased at 30 degrees C in both non-vitellogenic and vitellogenic fish. The liver RNA, however, showed a reduction with the rise of temperature at nonvitellogenic stage, but it increased at higher temperature (25 or 30 degrees C) at vitellogenic stage. The protein content of muscle enhanced with the rise of temperature in both non-vitellogenic and vitellogenic fish. The muscle RNA, however, remained unchanged at different acclimatory temperature. The gonadosomatic index increased after acclimation at 30 degrees C both at non-vitellogenic and vitellogenic stage. The protein content of ovary increased at these 2 stages with the rise of temperature from 15 to 25 degrees C and from 25 to 30 degrees C but the ovarian RNA changed in opposite direction (reduction) under these conditions. The DNA content of liver of non-vitellogenic fish and of muscle of both non-vitellogenic and vitellogenic fish did not alter with the change in acclimation temperature. The liver DNA showed a reduction at vitellogenic stage with the rise of temperature. The DNA content of ovary increased at non-vitellogenic stage and decreased at vitellogenic stage after acclimation at 30 degrees C.

Acclimatization↗
PubMed1983

Stability of the paraoxonase phenotyping ratio in collections of human sera with differing storage times.

Results from automated testing of 673 human sera, divided into four batches by duration of storage at -20 degrees C, indicated that paraoxon-hydrolysing activity, a, decreased with increased storage time. By contrast, the paraoxonase phenotyping ratio, c/b, a ratio designating enzyme activation by Na+ in the presence of Ca2+, was stable over a four year storage period.

Aryldialkylphosphatase↗
PubMed1982

Purification and characterization of an acidic trypsin/subtilisin inhibitor from tortoise egg white.

Egg whites of three species of tortoise and turtle have been compared by gel chromatography for inhibitory activity against proteases. The egg white of Geomyda trijuga trijuga Schariggar contains trypsin/subtilisin inhibitor while the egg white of Caretta caretta Linn. contains both trypsin and chymotrypsin inhibitors. No protease inhibitory activity has been detected in the egg white of Trionyx gangeticus Cuvier. An acidic trypsin/subtilisin inhibitor has been purified to homogeneity from the egg white of tortoise (G. trijuga trijuga). It is a single polypeptide chain of 100 amino acid residues, having a molecular weight of 11,700. It contains six disulphide bonds and is devoid of methionine and carbohydrate moiety. Its isoelectric point is at pH 5.95 and is stable at 100 degrees C for 4 hr at neutral pH. The inhibitor inhibits both trypsin and subtilisin by forming enzyme-inhibitor complexes at a molar ratio close to unity. Their dissociation constants are 7.2 x 10(-9) M for bovine trypsin and 5.5 x 10(-7) M for subtilisin. Chemical modification of amino groups with trinitrobenzene sulfonate has reduced its inhibitory activities against both trypsin and subtilisin, but the loss of its trypsin inhibitory activity is faster than that of its subtilisin inhibitory activity. It has independent binding sites for inhibition of trypsin and subtilisin.

Amino Acids↗
PubMed1982

Drug-plasma protein binding in Kutchin Athapaskan indians.

Free fractions of diazepam (D alpha), warfarin (W alpha), and methadone (M alpha) were measured in plasma obtained from 37 Kutchin Athapaskan Indians. Mean D alpha (3.42%) varied directly with free fatty acid concentration (r = 0.65, P less than 0.001) and was higher than previously found in other groups. These higher levels of fatty acids were associated with lower W alpha (r = -0.43, P = 0.007), and W alpha rose with time after a meal (r = 0.42, P = 0.01) when fatty acids usually fall. Mean W alpha was 0.72% and increased with age (r = 0.47, P = 0.004). In multivariate analysis, age, fatty acids, and time after the last meal together accounted for 42% of intersubject variation in W alpha. W alpha and D alpha were inversely correlated (r = -0.33, P = 0.04), a result of the strong effects of fatty acids in these drugs. In contrast to both D alpha and W alpha, intersubject differences in M alpha correlated inversely with alpha 1-acid glycoprotein concentration (r = -0.50, P = 0.001), but not fatty acids.

Adolescent↗
PubMed1982

On the morpho-histology of the alimentary tract in the Indian climbing perch, Anabas testudineus (Bloch), in relation to food and feeding habits.

Functional morpho-histology of the alimentary tract of the Indian Climbing perch, Anabas testudineus (BLOCH) has been described. The fish possesses a wide, slightly upturned mouth. The presence of jaw, vomerine, palatine, pharyngeal, and horny pad teeth in the bucco-pharyngeal region indicates the carnivorous feeding habit of the fish. Gill-rakers are toothed but the tongue is edentulous. The latter helps in manipulation of larger prey. The nature and disposition of the taste buds in the lips and bucco-pharyngeal region indicate that the fish procures its food primarily by taste and secondarily by sight. Taste buds are also present in the middle oesophagus which indicates that the gustatory sense extends upto this region. The surface epithelium of the cardiac stomach is conspicuous in having specific mucous cells. The pyloric stomach indicates a more primitive nature due to the presence of tubular mucous glands or pyloric glands. The number of pyloric caeca is 4. The intestine is slightly looped and the dimensionless RLG (Relative Length of the Gut) is 0.42. An ileo-rectal valve and the mucosal folds distinguish the rectum from the intestine.

Animals↗