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Biomedical subjects

S Ghatak

Publications and source records attributed to S Ghatak.

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

Antigenic characterization of excretory-secretory products of Setaria cervi.

Excretory-secretory products (ES) of Setaria cervi, a bovine filarial parasite, were prepared by in vitro maintenance of the worms in a protein free defined medium at 37 degrees C. RPMI-1640 medium proved to be the best as the worms remained motile in it for the maximum period of time without change of medium, and approximately 12-15 mg protein per 100 adult worms could be obtained. Crossed immunoelectrophoretic analysis of ES products revealed 11-15 antigens and most of them were common to somatic antigenic preparations from both adult worms and microfilariae. The ES products were also found to contain 3-4 host proteins, including serum albumin.

Animals↗
PubMed1986

Characterization of lactate dehydrogenase of Plasmodium knowlesi.

Some properties of purified lactate dehydrogenase, (EC. 1.1.1.27) from schizonts of Plasmodium knowlesi are described. The plasmodial enzyme migrated as single entity on polyacrylamide gel, and resembled rabbit muscle (M4) lactate dehydrogenase in its electrophoretic mobility. The P. knowlesi enzyme consisted of four identical subunits of 31 kDa. Purified lactate dehydrogenase was inhibited almost completely when incubated with 100 microM p-chloromercuribenzoate, Ag+ or Hg+ and such inhibition could be reversed by the addition of beta-mercaptoethanol or L-cysteine. Metal chelators did not show any remarkable effect. Oxalic acid is a competitive inhibitor of pyruvate reduction by this enzyme with apparent Ki of approximately equal to 0.41 mM.

Animals↗
PubMed1986

Purification and properties of lactate dehydrogenase from Plasmodium knowlesi and erythrocytes of the rhesus monkey.

Lactate dehydrogenase, E.C.1.1.1.27 (LDH) from the simian malarial parasite, Plasmodium knowlesi, and from normal rhesus monkey erythrocytes has been purified using Blue Sepharose affinity chromatography, and the properties of the purified enzyme from these two sources have been compared. The enzyme from the host and parasite were different in their kinetic properties, viz., substrate and pH optima, thermostability and isoenzymic behaviour. Partially purified LDH of the erythrocytes resolved into three isomeric bands on polyacrylamide gel electrophoresis, whereas the parasite LDH moved as a single enzyme band of different mobility from the host LDH. The molecular mass of the parasite enzyme was estimated as 117,500 daltons.

Animals↗
PubMed1986

Protein and antigenic composition of adult and microfilarial stages of Setaria cervi.

The protein and antigenic pattern of adult (female/male) and microfilarial stages of Setaria cervi, a bovine filarial parasite, was studied using certain immunochemical techniques. SDS-polyacrylamide gel electrophoretic analysis showed the presence of 35-40 protein bands in adults and 25-29 protein bands in microfilariae in molecular weight range of 10,000-200,000. Immunoelectrophoresis revealed the presence of 9-10 precipitin lines in adult and only 4 precipitin lines in microfilarial antigenic preparations. Crossed immunoelectrophoresis resolved these antigenic preparations further, and revealed the presence of 22-24 antigens in adults and 12-14 in microfilariae. These results demonstrate complex nature of somatic extracts of adult stage as compared to microfilariae and also reveal some qualitative and quantitative differences between these stages.

Electrophoresis, Polyacrylamide Gel↗
PubMed1985

Hepatic acid hydrolases of albino rats, Mastomys natalensis and albino mice during Plasmodium berghei infection.

Changes in liver acid hydrolase activities during the infection of albino rats, Mastomys or mice with Plasmodium berghei are described. B-Glucosidase, B-galactosidase and N-acetyl-B-D-glucosaminidase exhibited widely different responses with acid phosphatase and cathepsin-B the least responsive and are likely to be causally related to immunity of animals.

Acetylglucosaminidase↗
PubMed1985

Nippostrongylus brasiliensis: occurrence of multiple protein kinases.

The presence of cyclic AMP-dependent protein kinase and phosvitin kinases, with activity independent of cyclic nucleotides, was shown in the intestinal nematode Nippostrongylus brasiliensis. The activity of the cyclic AMP-dependent protein kinase was found to be enhanced about 8-fold in the presence of 10(-7) M cyclic AMP; the apparent Km values were determined to be 20 microM and 80 microM for ATP and kemptide, respectively. The molecular weight of the holoenzyme was about 170 000. Two phosvitin kinases could be isolated and distinguished by their molecular weights of 600 000 and 40 000. The activity of the high-molecular-weight phosvitin kinase was effectively inhibited by suramin and heparin. The apparent Km values were found to be 30 microM and 0.1 mg/ml for ATP and phosvitin, respectively. In the case of the low-molecular-weight phosvitin kinase the apparent Km values for ATP and phosvitin were found to be 30 microM and 0.6 mg/ml, respectively. The investigation of different developmental stages of N. brasiliensis revealed a marked higher level of protein kinase activity in the L4 larvae compared to L3 larvae and adults.

Animals↗
PubMed1985

Characterization of mitochondrial monoamine oxidase of Ascaridia galli.

Oxidative deamination of various biogenic monoamines by Ascaridia galli monoamine oxidase (MAO) was blocked by different mammalian MAO inhibitors, namely, iproniazid, trans-PcP, nialamide and pargyline and the blockade was observed to be time as well as concentration dependent. The binding of inhibitors with chick ascarid MAO was of the irreversible type and the nature of the inhibition was competitive. Pargyline showed lowest I50 (8 microM) and Ki (12 microM) values. Chlorgyline and deprenyl at 100 microM concentration inhibited MAO by about 60 and 40% respectively, indicating the presence of both type A and type B MAO in A. galli.

Animals↗
PubMed1985

Studies on the causation of adverse reactions in microfilaraemic host following diethylcarbamazine therapy (Dipetalonema viteae in Mastomys natalensis).

The mechanism of the adverse reaction in microfilaraemic subjects following diethylcarbamazine (DEC) therapy has remained an enigma. To study the mechanisms involved Mastomys natalensis infected with Dipetalonema viteae have been used. Animals showing up to 50 mf/5 cmm of blood did not show any perceptible reactions when treated with the minimum effective dose of 350 mg/kg of DEC citrate, while those having more than 80 mf/5 cmm died, suggesting an intensity dependent severity of reactions. Infective larvae contained maximum amounts of biogenic amines followed by mf and adults in that order. 16 mg of histamine or 24 mg of 5-hydroxytryptamine caused death when injected into healthy animals, whereas sonicated mf (5 million) and adult somatic products (4 mg protein) did not, signifying that the biogenic amine contents of the parasites were less than the critical level to cause death. Adult somatic products did not produce any visible reactions when injected into animals with microfilariaemia, but sonicated mf (5 million) caused death. It is concluded that the adverse reactions seen after DEC treatment are due to the release of biogenic amines in an anaphylactic type of reaction subsequent to massive release of parasite antigen in a sensitised host, which is directly proportional to the intensity of microfilaraemia and that the adverse reactions are not due to liberation of endogenous biogenic amines from dead mf.

Animals↗
PubMed1984

Ascaris lumbricoides and Ascaridia galli: biogenic amines in adults and developmental stages.

Ascaris lumbricoides var. hominis and Ascaridia galli contain 5-hydroxytryptamine, histamine, dopamine, and norepinephrine. The chick parasite showed lower levels of monoamines compared to human ascaris. Amine concentrations in females were higher than in males. In all specimens, 5-hydroxytryptamine was the highest while norepinephrine was found to be uniformly low. The female reproductive organ contained the maximum amount of dopamine while intestine was rich in histamine. A progressive increase in the concentrations of biogenic amines was noticed during development.

Animals↗
PubMed1984

Erythrocyte membrane-bound enzymes in Mastomys natalensis during Plasmodium berghei infection.

The pattern of activity of certain membrane-associated enzymes was followed in the erythrocytes of Plasmodium berghei-infected Mastomys natalensis. Parasitized erythrocytes were separated from non-parasitized populations by percoll-density gradient centrifugation. The activity of adenylate cyclase was markedly increased while those of ATPase, acid phosphatase, beta-glucuronidase and N-acetyl-beta-D-glucosaminidase were considerably decreased in the membrane preparations of parasitized erythrocytes as compared to normal erythrocytes. There was a decrease in the activity of ATPase and an increase of adenylate cyclase in the membrane preparations of non-parasitized erythrocytes. However, other enzymes did not alter to a significant extent in non-parasitized erythrocytes. Chloroquine (in vitro) stimulated adenylate cyclase, Na+, K+-ATPase and Ca++Mg++-ATPase while acetylcholinesterase was significantly inhibited.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1984

Protein kinases in different life stages of Brugia malayi and other filarial worms.

The investigation of protein kinase activity in different life stages of a few filarial worms indicates the presence of different protein kinases and of dissimilarities between the distribution pattern of these enzymes during the development. Phosvitin turned out to be the preferred exogenous acceptor protein, when homogenates of adults of Brugia malayi, Dipetalonema viteae, Setaria cervi and Litomosoides carinii were used as source of enzyme. In contrast to adults the L3-larval and the microfilarial stages demonstrated much lower phosvitin phosphorylating activity and the preference for acidic and basic proteins as phosphate acceptors was about equal. The occurrence of cyclic AMP-dependent protein kinase was established for adults of B. malayi.

Animals↗