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Biomedical subjects

B Lal

Publications and source records attributed to B Lal.

At least 55 records · Page 3Linked to original sources
PubMed1987

Impact of pesticides on lipid metabolism in the freshwater catfish, Clarias batrachus, during the vitellogenic phase of its annual reproductive cycle.

Specimens of either sex of the freshwater catfish Clarias batrachus were exposed to safe and sublethal concentrations of an organochlorine, gamma-BHC (2 and 8 ppm), and an organophosphorus compound, malathion (1 and 4 ppm), for 4 weeks during the vitellogenic phase of their annual reproductive cycle. The effects on total lipid and its various fractions, viz., free fatty-acids, monoglycerides, diglycerides, triglycerides, phospholipids, free cholesterol, and esterified cholesterol, were studied in the liver, plasma, gonads, and muscle. Except for elevated liver lipid in the male in response to malathion, no significant change in total lipid could be observed following pesticide exposure. However, various lipid fractions responded differently to two concentrations of the pesticides. Both pesticides affected the metabolism of nonpolar and less polar lipids alike. Malathion inhibited only mobilization of hepatic phospholipid to gonads but not its hepatic biosynthesis, whereas gamma-BHC reduced its synthesis in the liver as well. These pesticides seemed to restrict the conversion of esterified cholesterol into free cholesterol without affecting the biosynthesis of cholesterol as such. In both sexes, esterification of free fatty acids to acyl glycerides and their mobilization from liver to gonads seemed to be restricted as a result of pesticides action.

Animals↗
PubMed1987

gamma-BHC- and cythion-induced alterations in lipid metabolism in a freshwater catfish, Clarias batrachus, during different phases of its annual reproductive cycle.

Specimens of either sex of the freshwater catfish Clarias batrachus were exposed to safe and sublethal concentrations of gamma-BHC (2 and 8 ppm) and Cythion (1 and 4 ppm) for 4 weeks during different phases of the annual reproductive cycle. Their effects on various lipid fractions, viz., triglycerides (TG), phospholipids, free cholesterol, and esterified cholesterol, were studied in liver, plasma, gonads, and muscle. These pesticides suppressed the level of hepatic TG in females during the preparatory, prespawning, and postspawning phases, while during the spawning phase they stimulated an increase in its level. However, in males, these pesticides were ineffective in having any effect on liver TG during the spawning and postspawning phases, but in the preparatory phase, as with the female, they increased its levels, while in the prespawning phase they decreased liver TG levels. Hepatic phospholipid biosynthesis was impaired by gamma-BHC but Cythion had no effect on it. Cholesterol biosynthesis as such appeared to be unaffected by these pesticides but the dynamics of free and esterified cholesterol levels were disturbed in response to Cythion and gamma-BHC. These pesticides greatly reduced the mobilization of these hepatic lipids to gonads. Muscle lipids were least affected by these pesticides.

Animals↗
PubMed1987

The effect of malathion and gamma-BHC on the lipid metabolism in relation to reproduction in the tropical teleost, Clarias batrachus.

In the present study, female Clarias batrachus were exposed to two sublethal concentrations of gamma-BHC (2 and 8 microg litre(-1)) and malathion (1 and 4 microl litre(-1)) for 4 weeks during different phases of their reproductive cycle. Impact of these pesticides on free fatty acids, monoglycerides, diglycerides, triglycerides, phospholipids, free and esterified cholesterol in the liver, plasma, ovary and muscle was assessed. During the pre-vitellogenic and regressed phases, they suppressed the levels of fatty acids and glycerides in the liver, but had no effect on their levels in the plasma, ovary and muscle. However, in the vitellogenic phase, fatty acids in the liver and plasma were increased, but were decreased in the ovary and muscle. Glycerides were also decreased in the studied tissues. In the post-vitellogenic phase, these pesticides increased the levels of fatty acids and glycerides in the liver and ovary, but decreased their levels in the plasma. Both pesticides decreased hepatic phospholipids in the pre-vitellogenic phase, while in the vitellogenic phase only gamma-BHC reduced its levels in the liver. These pesticides also restricted their mobilisation to the ovary. Cholesterol biosynthesis seemed unaffected, but the hydrolysis of esterified cholesterol to free cholesterol was adversely affected during the period of estrogen biosynthesis.

Journal Article↗
PubMed1987

The effect of lead exposure on the testis of growing rats.

Daily intraperitoneal administration of lead (8 mg/kg) as lead acetate in male rats from 21 till 120 days of age triggered histopathological and biochemical alterations in the testis. Histopathological examination revealed disturbance in spermatogenesis besides Leydig cells degeneration. There was an increase in cholesterol, decrease in ascorbic acid contents and reduction in the glucose-6-phosphate dehydrogenase activity in the testis of lead-treated rats. These alterations suggest that the disturbed steroidogenesis during growing stage may be responsible for altering the germinal function of the testis at maturity.

Animals↗
PubMed1986

In vivo modification of fatty acids and glycerides metabolism in response to 1,2,3,4,5,6-hexachlorocyclohexane and cythion exposure in the catfish, Clarias batrachus.

Specimens of either sex of the freshwater catfish, Clarias batrachus, were exposed to safe and sublethal concentrations of gamma-BHC (2 and 8 ppm) and cythion (1 and 4 ppm) for 4 weeks during different phases of annual reproductive cycle. Their effects on free fatty acids (FFA) and acyl glycerides, viz., monoglycerides (MG), diglycerides (DG), and triglycerides (TG), were studied in liver, plasma, gonads, and muscle. During the preparatory phase, both pesticides suppressed the levels of FFA and acylglycerides (MG, DG, and TG) in liver of either sex but had no effect on their levels in plasma, ovary, and muscle; however, FFA and TG were reduced in testis. Unlike the preparatory phase, in the prespawning phase different lipids responded variedly to the concentrations of both Cythion and gamma-BHC. In the female, FFA in liver and plasma was raised but in ovary and muscle it was decreased. Acylglycerides in studied tissues were also reduced except ovarian TG which was increased by both pesticides at safe concentrations. Contrary to this, in the male these lipids were raised in liver and testis. Moreover, during the spawning phase, these pesticides enhanced the hepatic FFA together with acylglycerides in the female but failed to elicit any change in their levels in the male. Plasma levels of FFA and TG were reduced in the female; however, in the male FFA was raised and TG remained unchanged. Ovarian FFA and TG were decreased and increased, respectively. During the postspawning phase, none of the lipid fractions could be affected in the male except hepatic FFA which was reduced; however, in the female TG along with FFA was decreased.

Animals↗
PubMed1984

Trequinsin, a potent new antihypertensive vasodilator in the series of 2-(arylimino)-3-alkyl-9,10-dimethoxy-3,4,6,7-tetrahydro-2H-py rim ido [6,1-a]isoquinolin-4-ones.

Series of 3-substituted-9,10-dimethoxy-3,4,6,7-tetrahydro-2H-pyrimido [6,1-a]isoquinoline-2,4-diones and 2-substituted-9,10-dimethoxy-6,7-dihydro-4H-pyrimido [6,1-a]isoquinolin-4-ones were synthesized and tested for blood pressure lowering properties in anesthetized normotensive cats and conscious spontaneously hypertensive rats. Several compounds in the 2-(arylamino)-9,10-dimethoxy-6,7-dihydro-4H-pyrimido [6,1-a]isoquinolin-4-one series display a high order of activity. The most active compounds are the alkyl derivatives of the 2-mesitylamino/2-mesitylimino tautomeric forms. The 2-(mesitylimino)-3-methyl analogue trequinsin is a potent antihypertensive agent and displays a hemodynamic profile characteristic of an arteriolar dilator. It is also a potent inhibitor of both cAMP phosphodiesterase and platelet aggregation.

Animals↗
PubMed1983

Clinical and experimental keratitis caused by the Colletotrichum state of Glomerella cingulata and Acrophialophora fusispora.

Two cases of mycotic keratitis caused by the Colletotrichum state of Glomerella cingulata and Acrophialophora fusispora are reported for the first time. Both the isolates produced experimental corneal lesions in rabbit eyes but A. fusispora was more pathogenic. The experimental infection was more severe, with both the fungi, in rabbits pretreated with cortisone as compared with untreated animals. In vitro A. fusispora was most sensitive to miconazole and tolciclate followed by clotrimazole, amphotericin B and lactones while clotrimazole exerted maximum inhibitory effect on Colletotrichum followed by miconazole, lactones, amphotericin B and arnebins. Arnebins and tolciclate were inactive respectively against A. fusispora and Colletotrichum. Of the 3 drugs tested in vivo, against A. fusispora keratitis in rabbit, amphotericin B showed better results than tolciclate and miconazole.

Adult↗
PubMed1982

Clinical and experimental keratitis due to Curvularia lunata (Wakker) Boedijn var. aeria (Batista, Lima and Vasconcelos) Ellis.

A case of mycotic keratitis due to Curvularia lunata var. aeria is reported for the first time from India. Direct microscopic examination of the corneal scrapings in KOH (50 g1(-1)), stained with lactophenol cotton blue, revealed brown septate hyphae and the cultures were found positive for fungus. It was identified as C. lunata (Wakker) Boedijn var. aeria (Batista, Lima and Vasconcelos) Ellis (IMI 253204) and its growth was better at 28 degrees C than at 37 degrees C. In vitro, the fungus was most sensitive to amphotericin B followed by miconazole nitrate, clotrimazole and triphenyltin isoselenocyanate 4-picoline which had the same activity. Lactones were least active and tolciclate and arnebins and inactive. The fungus produced experimental keratomycosis in the rabbit cornea and the infection severity as well as histopathological changes were more pronounced in rabbits that received penicillin, streptomycin and cortisone.

Adult↗
PubMed1979

Studies on a strain of Fusarium solani (Mart.) Sacc. Isolated from a case of mycotic keratitis.

A strain of Fusarium solani (Mart.) Sacc. (IMI-216517), isolated from a patient of mycotic keratitis, produced experimental keratomycosis in albino rabbit cornea and survived in internal tissues of albino mice for varying periods. Alantolactone, isolated from the plant - Inula racemosa Hook. f. exhibited marked in vitro fungistatic activity against this strain of F. solani at 100-200 microgram/ml concentrations. The strain was less sensitive to amphotericin B and showed more acid than alkaline proteinase and phosphatase activities.

Adult↗
PubMed1979

Orbital paecilomycosis due to Paecilomyces lilacinus (Thom) Samson.

The first case of orbital paecilomycosis is described. Fungal hyphae were found in a KOH preparation of the granulomatous tissue, removed from the orbit, and also in histological sections. Culture of the tissue was positive for fungus which was resistant to cycloheximide (0.5 g/l). It was identified as Paecilomyces lilacinus (Thom) Samson (IMI 213487) and shown to be pathogenic for the rabbit cornea.

Adult↗