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Biomedical subjects

S Kaur

Publications and source records attributed to S Kaur.

At least 307 records · Page 17Linked to original sources
PubMed1985

Identification and characterization of hepatic carboxylesterases hydrolyzing hydrocortisone esters.

The present study has provided evidence for the existence of three distinct carboxylesterases involved in the hydrolysis of steroid esters, where two enzymes are possibly responsible for the metabolism of hydrocortisone hemisuccinate (HCHS) at pH 5.5 and 8.0, and a third enzyme for the metabolism of hydrocortisone acetate (HCAC) at pH 8.0, in isolated rat liver microsomes. The activity of all three enzymes in rat liver was induced significantly by the administration of phenobarbital while no such function in enzyme activity was observed in animals receiving 3-methylcholanthrene or benzo[a] pyrene under similar experimental conditions. The increase in the activity of HCHS esterase I (HCHS-E1) active at pH 5.5, HCHS esterase II (HCHS-E2) active at pH 8.0, and HCAC esterase (HCAC-E) was approximately 7 to 8, 3- and 3-fold respectively. On the other hand, the degree of induction of nonspecific microsomal carboxylesterase acting on p-nitrophenylacetate (PNPA) was significantly less. The Km values for the hydrolysis of HCHS at pH 5.5 and 8.0 and HCAC by rat liver microsomes obtained from control rats were 2.45, 2.02 and 1.6 mM, respectively, and these Km values were not changed significantly in preparations obtained from rats treated with phenobarbital. The distinct in vitro responses displayed by hepatic microsomal steroid esterases to various inhibitors were able to distinguish three different enzymes which also differed from nonspecific carboxylesterases. The activity of HCAC-E was inhibited by NaAsO2 and AgNO3 while that of HCHS-E1 and HCHS-E2 remained unaffected. Selective inhibition of HCHS-E1 by NaF, HgCl2 and p-chloromercuribenzoate and that of HCHS-E2 by NiSO4 indicated the possible existence of different enzymes or isozymes of a carboxylesterase catalyzing HCHS hydrolysis. The effects elicited by the inhibitors on the activity of PNPA esterase were different from those observed with steroid esterases. Furthermore, the present study has also indicated species variations in the distribution of steroid esterases in the livers of rat, mouse, dog and cat.

Animals↗
PubMed1985

Prevalence of bacteria and fungi in athlete's foot of varying severity and response to topical antibacterial and antifungal therapies.

Ninety-six patients with clinical evidence of interdigital lesions classified as mild, moderate and severe athlete's foot were investigated for bacterial and fungal populations in the interspaces. Gram-negative bacteria, which were not found in the toe spaces of 50 normal controls, were grown in increasing numbers and with increasing frequency as the symptoms progressed from mild to severe. Gram-positive bacteria were also isolated regularly and in increasing numbers commensurate with the severity of the disease. Similarly the isolation rates of dermatophytes and Candida species were higher in patients with moderate and severe disease compared to those with mild disease. Clinical and culture responses to topical applications with framycetin, tolnaftate, miconazole and clotrimazole were also studied. In some patients the prevalence of pathogenic fungi increased as bacterial numbers decreased. The pure antibacterial framycetin brought symptomatic relief, as did the purely anti-dermatophyte substance tolnaftate, but best results were seen with two azole compounds having mixed antibacterial and antifungal properties.

Adult↗
PubMed1985

Phagocytic and bactericidal activities of macrophages from Mycobacterium leprae-infected normal and immunosuppressed mice.

Phagocytic and bactericidal activities were studied in Mycobacterium leprae-infected normal (NI) and thymectomized/irradiated (TRI) mice at different time periods. No significant differences were seen in the phagocytic activity for Staphylococcus aureus at 3, 6, and 9 months in the normal infected (NI) and normal control (NC) mice. A slight but significant decrease in the phagocytosis of S. aureus was seen in the TRI as compared to the NI group at 3 months which recovered at 6 months. Phagocytosis of sheep erythrocytes was depressed in the TRI as compared to the NI group at 6 months only. No significant differences in the phagocytosis of latex particles were seen in any of the groups at any time of infection. Bactericidal activity was significantly reduced in the NI group as compared to the NC group and, similarly, in the TRI group as compared to the TRC group at all periods of infection. The M. leprae-infected T/R 900 group (TRI) showed more decrease in bactericidal activity when compared to the normal infected (NI) group.

Animals↗
PubMed1984

Anti-inflammatory activity of Euphorbia acaulis Roxb.

From various extracts of Euphorbia acaulis , the n-hexane fraction showed marked anti-inflammatory activity in carrageenan induced oedema in rats and mice as compared to phenylbutazone and was equipotent in adrenal- ectomised rats. In chronic models of formaldehyde and adjuvant arthritis, its anti-arthritic activity was found to be superior to that of phenylbutazone. It had a diuretic effect but did not show any analgesic or antipyretic activity.

Analgesics↗
PubMed1983

Selective induction of xenobiotic metabolizing esterases/amidases of liver by methaqualone consumption.

The present investigation reports the influence of po and ip methaqualone administration on the hydrolytic metabolism of acetylsalicylic acid, procaine, p-nitrophenylacetate, acetanilid, and butyrylcholine in the liver, kidney, and brain of male rats. Oral administration of methaqualone (60 mg/kg/day) to rats for 20 days caused 41.0, 46.5, and 55.0% stimulation of acetylsalicyclic acid esterase I, acetylsalicyclic acid esterase II, and acetanilid N-deacetylase, respectively, in the liver. Under such conditions, the activities of other esterases remained unaffected. The responses of tissue esterases to ip methaqualone treatment (40 mg/kg/day for 6 days) were similar to those observed after po methaqualone administration. Since a single po dose of methaqualone failed to produce any alteration in the rate of metabolism of acetylsalicylic acid, procaine, p-nitrophenylacetate, acetanilid, and butyrylcholine within 20 hr, it may be interpreted that the stimulation of acetylsalicylic acid and acetanilid metabolism is possibly due to selective enhanced de novo synthesis of the enzymes/isozymes necessary for the hydrolysis of the two drugs. The ability of the kidney and brain to metabolize the esters/amides was not modified by po or ip methaqualone pretreatment suggesting the possibility of noninducible forms of renal and neuronal esterases/amidases.

Amidohydrolases↗