Search PubMed⌕ Search

Biomedical subjects

P Kaul

Publications and source records attributed to P Kaul.

At least 37 records · Page 2Linked to original sources
PubMed1995

Vitamin B6 deficiency and galactose induced alterations in morphology and osmotic fragility of rat erythrocytes.

Recently, red blood cells have been investigated mainly for alterations in ion transporting capacity, membrane bound enzymes or modifications in the structure of its individual constituents in clinical and experimental urolithiasis. However, the implication of such modifications on the physical state or morphology of cells has not been investigated. Scanning electron microscopic studies performed in vitamin B6 deficient and/or galactose fed rat (established hyperoxaluric models) erythrocytes, showed the presence of large number of stomatocytes, spherocytes and other variously deformed cells as compared to discocytic cells seen in normal control group. These changes in shape were in concurrence with red cell osmotic fragility, which decreased both in vitamin B6 deficient and vitamin B6 deficient + galactose fed group (19 % and 33 % hemolysis at 4 g/l NaCl, respectively) while it increased in galactose control group (73 % hemolysis at 4 g/l NaCl) as compared to normal control group (55 % hemolysis at 4 g/l NaCl). These morphological and physical state alterations could be correlated with red blood cells' membrane cholesterol and phospholipid sub-class distribution. These findings suggest that some structural membrane changes occur due to vitamin B6 deficiency and/or galactose feeding, which may be responsible for the altered membrane functions known to be associated with pathogenesis of urolithiasis.

Animals↗
PubMed1994

Study of urinary calcium excretion after oral calcium load in stone formers, their spouses and first-degree blood relatives.

Hypercalciuria has long been considered a common abnormality in stone formers, and familial predisposition to renal stone formation has also been reported. Renal stone formers, their spouses and first-degree blood relatives (the latter two groups of subjects had no previous or present history of stone disease) were investigated for their response to an oral load of 2 g calcium (as di-calcium phosphate). Serum calcium, phosphorus, uric acid, creatinine and urea were within the normal range in all the subjects initially as well as 4 h after the load. After the oral calcium load, 66.6% of the stone formers, 25% of the first-degree relatives and none of the spouses were hypercalciuric. Administration of 2 g calcium produced a significantly greater urinary excretion of calcium in stone formers (123.8 +/- 43 mg/8 h, p < 0.001) and their first-degree blood relatives (89.8 +/- 26 mg/8 h, p < 0.01) as compared to the spouses of stone formers (65.5 +/- 12.8 mg/8 h). A significant increase in urinary calcium excretion after calcium loading was also found among the stone formers (p < 0.01) as compared to their first-degree blood relatives. A significantly higher mean rise in calcium excretion (over the basal excretion) in calcium stone formers (p < 0.001) and their first-degree blood relatives (p < 0.01), as compared to the spouses of stone formers suggests a greater predisposition to renal stone disease in first-degree blood relatives than the spouses of the stone patients.

Administration, Oral↗
PubMed1993

Tetralogy of Fallot: intracardiac repair in 840 subjects.

Since 1967, when the first intracardiac repair was performed in this centre, until 1991, 840 symptomatic subjects with tetralogy of Fallot have undergone corrective surgery. Cardiac catheterization and angiocardiography were carried out in all patients. Cardinal findings on the clinical status of these subjects are outlined. A substantial number of patients (244; 29.0%) were > 15 years of age. Historically, a transannular pericardial gusset has been utilized in 578 (68.8%), and in 423 (93.0%) during the past decade. The incidence of residual interventricular septal defects has been 0.68% and occurrence of complete heart block after surgery 0.4%. Death occurred in 86 patients (10.2%) within 30 days of operation and later in 40 subjects (4.8%). Long-term results have been excellent with good haemodynamic status in > 90% of subjects in the follow-up period. Associated features including absent pulmonary valve, absent left pulmonary artery, and previous palliative shunts did not alter the outcome; however, a raised haematocrit (> 0.65) was associated with an increased mortality rate.

Adolescent↗
PubMed1993

A comparative study of erythrocyte oxalate flux rate and urinary oxalate excretion in hyperoxaluric rats.

The present study was carried out to investigate the relation between erythrocyte oxalate flux rate and the pathogenesis of calcium oxalate renal stone disease having hyperoxaluria as the main risk factor. Male albino rats were made hyperoxaluric by feeding them diets viz. vitamin B6 deficient, vitamin B6 deficient + 51.7% galactose or fructose (serving as a sole source of carbohydrate), along with their respective pair-fed controls for 4 weeks. After 28 days of feeding, oxalate excretion was in the order of vitamin B6 deficient + galactose > galactose control > vitamin B6 deficient + fructose > vitamin B6 deficient > fructose control/vitamin B6 control. Whereas, transmembrane oxalate flux rate was in the order of vitamin B6 deficient > vitamin B6 deficient + galactose > vitamin B6 deficient + fructose > vitamin B6 control > galactose control > fructose control. No significant correlation (r = 0.304) was found between the urinary oxalate excretion and erythrocyte oxalate flux rates of various groups of rats. The study indicates that increase in oxalate excretion does not concomitantly increase the transmembrane oxalate flux in red blood cells.

Alanine Transaminase↗
PubMed1992

Increased exposure of hydrophobic surface in molten globule state of alpha-lactalbumin. Fluorescence and hydrophobic photolabeling studies.

The involvement of molten globule state as a distinct intermediate in the denaturation process in proteins is well documented. However, the structural characterization of such an intermediate is far from complete. We have, using fluorescence and fluorescence quenching, studied the molten globule state of bovine alpha-lactalbumin. Unlike the native state, where all the 4 tryptophans are buried in the protein, 2 tryptophans are exposed in the molten globule state. Using the hydrophobic photoactivable reagent [3H]diazofluorene, we observe an increased hydrophobic exposure in the molten globule state. These structural characteristics conform to the current views on the molten globule state, i.e. it has similar secondary structure but a poorly defined tertiary structure. Our fluorescence studies indicate the involvement of a premolten globule state in the native to molten globule state transition. This premolten globule state exists at pH 5.0 and has a very compact structure involving increased hydrophobic interactions in the protein interior. These results are also supported by circular dichroism studies.

Animals↗
PubMed1983

Phosphoenolpyruvate shuttle--transport of energy from mitochondria to cytosol.

Brown-adipose tissue mitochondria of hamster and rat contain phosphoenolpyruvate carboxykinase (EC 4.1.1.32). In the presence of ketoglutarate and malate, phosphoenolpyruvate is formed and exported from mitochondria. Phosphoenolpyruvate formation is inhibited by 1,2,3-benzenetricarboxylate. It is proposed that phosphoenolpyruvate carboxykinase together with pyruvate carboxylase and pyruvate kinase forms a phosphoenolpyruvate shuttle through which energy produced by the Krebs cycle in mitochondria may be exported to cytosol.

Adipose Tissue, Brown↗
PubMed1979

Enhanced steroidogenesis in hen ovary after malonate administration.

The activities of glucose-6-phosphate dehydrogenase, delta 5-3 beta-hydroxysteroid dehydrogenase and succinic dehydrogenase have been studied histochemically in the ovary of normal and malonate treated hens. Following malonate treatment, glucose-6-phosphate dehydrogenase and delta 5-3 beta-hydroxysteroid dehydrogenase showed increased activities while succinic dehydrogenase activity was diminished significantly. The significance of the above changes has been discussed. The ascorbic acid and cholesterol contents of the ovary were determined to get additional information about steroidogenesis in the gland under such treatment.

3-Hydroxysteroid Dehydrogenases↗
PubMed1977

Pentose phosphate pathway and testicular steroidogenesis in rats following oxythiamine treatment.

Suppression of delta5-3beta-hydroxy steroid dehydrogenase (delta5-3beta-OHD) and glucose-6-phosphate dehydrogenase (G-6-P-D) activities along with concomitant stimulation of succinic dehydrogenase (SDH) activity were observed in the rat testicular tissues following treatment with oxythiamine HC1, an inhibitor of pentose phosphate pathway. The same treatment also resulted in an accumulation of cholesterol and ascorbic acid in the gland associated with a decrease in the weights of seminal vesicle and prostate. The results suggest a diminution in testicular steroid biogenesis following an alteration of pentose phosphate pathway.

3-Hydroxysteroid Dehydrogenases↗
PubMed1976

Leucyl naphthylamidase activity in pigeon and toad testes under various experimental conditions.

The activity pattern and functional significance of leucyl naphthylamidase (LNase) in the pigeon testis under different hormonal and photoperiod conditions as well as in the testes of short- and long-term HCG-treated toads have been studied histochemically. In both the species, the enzyme activity was present in the maturing spermatids and those embedded in the Sertoli cell components, the mature spermatozoa released in the lumen being devoid of any LNase activity. In pigeon, the stimulation of spermatogenic process was associated with enhanced activity of the enzyme, whereas arrest of spermatogenesis showed little or no activity. In toad, short-term HCG treatment caused mild stimulation of spermiation resulting in sperm release from the Sertoli cells and this was accompanied by moderate decrease in LNase activity. The long-term HCG treatment produced an enhanced stimulation of spermiogenesis and spermiation processes resulting in almost total disappearance of LNase activity. The above observations suggest that the enzyme in the testes of both species is related to spermiogenesis and/or spermiation events of spermatogenesis.

Animals↗
PubMedDate not supplied

Evaluation of a 200-kDa amastigote-specific antigen of L. donovani by enzyme-linked immunosorbent assay (ELISA) for the diagnosis of visceral leishmaniasis.

A purified 200-kDa antigenic fraction from Leishmania donovani axenic amastigotes was evaluated by ELISA for the detection of antibody response in visceral leishmaniasis (VL) patients, post kala-azar dermal leishmaniasis (PKDL) patients and controls, for the diagnosis of visceral leishmaniasis. A positive antibody response to the 200-kDa amastigote fraction and to Leishmania amastigote soluble antigen (LASA) was found in 29 (96.6%) and 30 ((100%) confirmed VL patients, respectively, by the use of ELISA. However, only 1 (10%) out of 10 PKDL patients had detectable antibody response to 200-kDa fraction while all the 10 (100%) PKDL patients exhibited an immune response to LASA. Therefore, use of the 200-kDa antigenic fraction for the detection of antibody response in an ELISA follow-up (post treatment) of VL patients may have prognostic significance, and it may also be useful for differentiating active VL and PKDL.

Animals↗
PubMedDate not supplied

Effect of eltroxine and neomercazol on monoamine oxidase from rat tissues.

The paper describes the effect of two drugs, (Eltroxine and Neomercazol) on the nature and activity of monoamine oxidase (MAO) in albino rats. Four organs namely liver, kidney, brain and heart were examined from this point of view. Biological activity measurements were done using tyramine hydrochloride as the substrate. The liver MAO from normal as well as the drug treated rats were subjected to DEAE gel filtration studies. These investigations show that there is a significant difference in the biological activity as well as in the actual nature of the enzyme as a result of treatment with the drugs mentioned above.

Animals↗