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K Mukherjee

Publications and source records attributed to K Mukherjee.

At least 55 records · Page 3Linked to original sources
PubMed1995

Renal dopamine receptors are involved in the development of cardiac hypertrophy.

The present study examined the effect of fenoldopam, a known dopamine-1 receptor (DA1) agonist in order to understand its involvement in the cardiac hypertrophic process. Male Sprague-Dawley rats underwent abdominal aortic constriction (AB) with placement of a suprarenal ligature while sham operated animals served as controls. The AB groups showed an increase in their heart wt, left ventricular (LV) wt, heart wt/body wt and LV wt/body ratio. Furthermore, the length of these hearts, as measured from the auriculoventricular border to the apex, LV wall and interventricular (IV) septal thickness were increased from control levels. Treatment with SCH 23390, a DA1 antagonist, on the other hand, was able to partially regress the cardiac hypertrophic changes. All these parameters were also increased in control animals treated with fenoldopam (F). Such changes were more striking in the F+AB group which showed a significant acceleration of the cardiac hypertrophic process on superimposing the two treatments. Plasma dopamine and renin activity were increased in all the groups as compared to control. These results indicate that dopamine receptors are implicated in the development of cardiac hypertrophy.

Animals↗
PubMed1995

Aflatoxin contamination of sorghum seeds during storage under controlled conditions.

Aflatoxins were estimated in two sorghum seed varieties (CSH-9 and AJ 140) collected in India and stored at three different temperature and humidity levels showed 20 degrees C and 73.5% relative humidity (RH) to be safe storage conditions. A maximum aflatoxin level was observed at 31 degrees C and 81.0% RH. Though the fungus grew well at 40 degrees C and all the humidity levels tested aflatoxin production was comparatively lower but reached hazardous level after 5 months of storage. Though all four aflatoxins were detected in both the seed samples, aflatoxin B1 and aflatoxin G1 were most predominant.

Aflatoxin B1↗
PubMed1994

Renal D1 receptors, and not D2, are upregulated after aortic constriction and may be involved in cardiac hypertrophy.

1. The characteristics of dopamine (D) receptors were studied in kidney using the radiolabelled receptor assay of [3H]-SCH-23390 for D1 and [3H]-sulpiride for D2 receptors during cardiac hypertrophy. Male Sprague-Dawley rats (175-200 g) underwent abdominal aortic constriction above the renal arteries and were studied 28 days thereafter. Sham operated animals without aortic constriction were used as control. 2. Membranes obtained from kidney cortex showed an increase in the number of binding sites (Bmax) of D1 receptors in the aortic banded group. The apparent affinity for the ligand (Kd) was unchanged with D1 receptors, as compared to sham control. Both Bmax and Kd were unchanged for D2 receptors in the aortic banded group. 3. Autoradiographic data further reinforced the findings, showing an increased number of D1 receptors in the kidney at 28 days after abdominal aortic constriction. These changes were associated with an increase in plasma renin activity in the aortic banded group. Further, Na(+)-K(+)-ATPase as measured by fmol of 32Pi released from [gamma-32P]-ATP, was decreased in the kidney cortex of banded animals. 4. Reversal of hypertrophic parameters was observed in the aortic banded group treated for 14 days with SCH 23390 hydrochloride (0.1 mg kg-1 i.p.), a known D1 receptor antagonist. 5. The present study shows an upregulation of renal D1 receptors following abdominal aortic constriction and it is suggested that upregulation of D receptors may be involved in the development of cardiac hypertrophy.

Animals↗
PubMed1993

Norepinephrine levels in paraventricular nucleus of spontaneously hypertensive rats: role of neuropeptide Y.

Recent evidence supports the view that the sympathetic system actively participates in the development of hypertension. Because norepinephrine, contained within central neurons involved in cardiovascular sympathetic regulation, is known to coexist with neuropeptide Y, it is possible that a functional interaction between neuropeptide Y and norepinephrine exists within the brain. In an effort to clarify whether or not central catecholamine systems are modulated by neuropeptide Y in hypertensive situations, the paraventricular nucleus of spontaneously hypertensive rats was exposed to neuropeptide Y (10(-9) M), and levels of norepinephrine were sampled by microdialysis. Norepinephrine levels in spontaneously hypertensive rats were significantly increased and did not change after exposure to neuropeptide Y, in sharp contrast to the decreases seen in Wistar-Kyoto controls. To ascertain whether these alterations in norepinephrine control were specific to the model used, a similar series of experiments was carried out in the paraventricular nucleus of aortic-banded rats. These studies supported the previous findings. Norepinephrine levels in aortic-banded rats were markedly elevated when compared with sham-operated controls and demonstrated no change after exposure to neuropeptide Y, whereas decreases of > 50% were seen in sham-operated controls. These results support the view that mechanisms normally involving neuropeptide Y as a neuromodulator in the paraventricular nucleus are altered in hypertensive situations. It is suggested that hypertension may precipitate changes in mechanisms involving brain neuropeptide Y and increased sympathetic activity.

Animals↗
PubMed1992

Altered renal dopamine receptors during development of cardiac hypertrophy.

The characteristics of dopamine receptors were studied in heart and kidney using the radiolabeled receptor assay of [3H]spiperone during the development of cardiac hypertrophy. Male Sprague-Dawley rats (175-200 g) underwent abdominal aortic constriction above the renal arteries and were studied 3, 14, and 28 days thereafter. Sham-operated animals without aortic constriction were used as control. Although the ratio of left ventricular weight to total body weight was significantly increased 14 and 28 days after aortic constriction in animals, [3H]spiperone binding in left ventricular membrane was increased as early as 3 days after aortic constriction. At 14 days, the binding was still elevated and, by 28 days, it returned to control values. In contrast, membranes obtained from kidney cortex showed an elevation of [3H]spiperone binding only at 28 days after aortic constriction; at 3 days the binding values were decreased. A reciprocal correlation was found between the number of dopamine receptors and the activity of Na(+)-K(+)-ATPase at 28 days of aortic constriction; the enzyme activity, as measured by the release of 32Pi from [gamma-32P]ATP, was decreased in kidney cortex. Autoradiographic data also showed an increased number of dopamine receptors in kidney at 28 days after abdominal aortic constriction. These results suggest that the dopamine receptor is increased very early in heart in response to pressure overload as a result of a compensatory response to maintain an optimal left ventricular output. Kidney dopamine receptors are triggered at a later stage possibly to maintain fluid homeostasis secondary to the cardiac hypertrophic process.

Animals↗
PubMed1990

Sensitivity of the different tests of enterotoxigenicity of Escherichia coli and their correlation.

Enterotoxigenicity of E. coli isolates was tested in 136 cases of acute gastroenteritis. Heat labile toxin (LT) produced in-vitro was tested in rabbit ileal loop (RIL); vero cell line and Biktn plate. The results of live cultures were evaluated in RIL. The overall data of these four models were not statistically different. Elaboration of LT in these four models ranged from 14-21.4%. Out of the 20 LT producing strains 14 (70%) also revealed ST. Of the 6 positive reactors on vero cell line, appeared to produce vero toxin (VT) only. Out of 29 LT positive E. coli, 1 (3.45%) and 2 (6.89%) strains respectively revealed colonising factor antigen (CFA) I and II. The high incidence of ETEC showing both LT and ST has been highlighted in the age group 0-4 years, and its impact on nutritional status is discussed.

Adolescent↗
PubMed1989

Experimental studies on membrane permeability defects of drug-resistant bacteria.

Multiply antibiotic-, lysozyme-and bacitracin-resistant, representative strains of staphylococci, Escherichia coli, Shigella dysenteriae and Klebsiella pneumoniae were compared respectively with their parent cultures in respect of their membrane permeability as judged by fluorescence polarization spectroscopy, using a sensitive fluorescent probe. The cytoplasmic membrane of the drug-resistant mutants was found to be less fluid and permeable, compared to that from the sensitive wild types. The study constitutes an attempt to determine the physical basis for the mechanism of resistance of certain bacteria against certain drugs.

Bacitracin↗
PubMed1987

Sequential radiation changes in cytology of vaginal smears in carcinoma of cervix uteri during radiotherapy.

The study deals with acute/immediate radiation changes in 2020 sequential vaginal smears in 101 patients of carcinoma of the cervix uteri, 97 were of squamous cell carcinoma and 4 of adenocarcinoma. The smears were collected after 12-14 days, 15-24 days and 25 days to 6 weeks following radiotherapy. The pretreatment vaginal smears were collected and examined for percentage of cancer cells. Subsequent smears were studied for radiation changes in benign and malignant cells, such as cell size, vacuolation of cytoplasm, multinucleation and nuclear changes, etc. A gradual and linear decline in cancer cells was observed until the end of therapy; 41.6% of patients had less than 10% cancer cells within 12-14 days of therapy, 63.4% of patients between 15 and 24 days and 74.6% after 25 days to 6 weeks following radiation. Eighty three percent of the patients attained zero level at the end of therapy.

Adenocarcinoma↗
PubMed1987

Glutamic oxalacetic and glutamic pyruvic transaminase activities in different tissues of rats and guinea pigs exposed to varying levels of altitude stress for different periods of time.

It was observed that both glutamic oxalacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) activities were significantly increased in different tissues of both rats and guinea pigs, during a short period of altitude exposure, as well as in acclimatized animals. Interestingly, it was found that oral administration of glucose showed no such significant change at either sea level or in a hypoxic condition. Studies on the activity of GOT and GPT in different tissues of normal guinea pigs showed a little change in liver and brain during short periods of exposure. Kidney and heart showed a significant increase in GOT activity without any change in GPT activity. Increased activities were observed in all the tissues of the acclimatized animals. Of both unexposed and acclimatized animals, there was no change in the enzyme of unexposed and acclimatized animals except in heart following injection of thyroxine (16 micrograms X kg-1), but the enzyme activities were most pronounced in scorbutic animals.

Alanine Transaminase↗
PubMed1986

Release of a lectin from a fatty acid auxotroph of Saccharomyces cerevisiae grown in presence of oleic acid.

The unsaturated fatty acid-requiring mutant KD 115 of Saccharomyces cerevisiae secretes a lectin when grown in presence of oleic acid. This lectin is homogeneous on PAGE at pH 8.3, has an approximate molecular weight of 320,000, pI of 4.2 and contains about 60% sugar. It agglutinates chicken and different mammalian erythrocytes, but lyses rabbit red cells only. It is D-galactose-specific. To our knowledge, this is the first report of a hemagglutinin from yeast.

Animals↗
PubMed1985

Locked twins.

Explore the source record for details and available documents.

Female↗
PubMed1985

Placental hormones as possible markers in gynaecological cancer.

Two placental hormones (human chorionic gonadotropin and human chorionic somatotropin) were assayed in serum of patients bearing a wide variety of malignant tumours. The incidences of these hormones were found to be higher among female patients. Further studies revealed that the incidence was high in patients with malignant tumours of the gonads, breast, uterus and cervix. It was shown that these hormones are the products of tumour cells and that they are released in circulation. Studies on cervix cancer suggest that they may be useful aids in following the course of therapy.

Adult↗