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Biomedical subjects

A K Bhattacharyya

Publications and source records attributed to A K Bhattacharyya.

At least 19 recordsLinked to original sources
PubMed1992

Variable expression of P-glycoprotein in normal, inflamed, and dysplastic areas in ulcerative colitis.

Screening programs for the detection of cancer in ulcerative colitis are inexact and not always successful in finding early, curable cancers. P-glycoprotein is a membrane-based, energy-dependent protein found in varying degrees within normal human tissue. P-glycoprotein is overexpressed in malignant tumors, particularly colorectal cancer, and is known to convey resistance to certain anticancer drugs by acting as a membrane "pump." The purpose of this study was to determine the expression of this protein in inflamed and premalignant colonic epithelium, compare its expression with normal controls, and assess its potential use as a screening tool for high-risk patients with ulcerative colitis. Using immunohistochemical techniques, the colons of 21 patients (10 with dysplasia) with ulcerative colitis were stained with monoclonal antibody C-219 (MAbC219) specific for P-glycoprotein. P-glycoprotein was expressed in 38 percent of normal areas, 71 percent of inflamed areas (P = 0.0156), and 70 percent of dysplastic areas. Comparing the level of expression when progressing from normal to inflamed areas within a given patient, 11 patients (52 percent) showed increased expression, 8 (38 percent) showed equal expression, and only 2 (10 percent) showed decreased expression (P = 0.0225). Comparing expression when progressing from inflamed to dysplastic areas (10 patients), 7 showed equal expression and 3 showed increased expression (P = 0.25). Increasing duration of disease was associated with a significant increase in P-glycoprotein expression, but only in histologically normal areas. Duration of disease had no effect on P-glycoprotein expression in inflamed or dysplastic areas. Similarly, when surgery was performed for elective reasons, there was a significant overexpression of P-glycoprotein, but only in histologically normal areas. Our findings suggest that the increase in P-glycoprotein expression from normal to inflamed and dysplastic areas reflects the premalignant nature of ulcerative colitis and occurs early in the course of the disease. Further research needs to be done to determine its role in cancer surveillance.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1992

Effect of intraoperative radiation on the tensile strength of small bowel anastomoses.

Increasing interest in the use of preoperative or intraoperative radiation therapy for cancer has led to concerns regarding tissue healing and integrity subsequent to treatment. This is especially so for intestinal anastomoses incorporating irradiated bowel, where poor healing may lead to anastomotic disruption and sepsis. One hundred thirty Sprague-Dawley rats were randomized into five groups as follows: both limbs, one limb, or neither limb of an anastomosis received 2,000 R of radiation intraoperatively. A fourth group had a segment of small bowel irradiated, with no anastomosis; a fifth group had the gut exposed by celiotomy. The control groups and all anastomoses underwent tensile strength measurements on the seventh postoperative day, with findings as follows: no anastomosis, no irradiation, 143.75 g; no anastomosis, irradiated, 114.50 g; anastomosis, no irradiation, 85.273 g; anastomosis, one limb irradiated, 78.100 g; anastomosis, both limbs irradiated, 59.00 g. There was no statistical difference in tensile strength of the anastomosis between when neither limb and when just one limb was irradiated. However, when both limbs were irradiated, the loss of strength was statistically significant (P = 0.002). Irradiation damage scores were assigned using Black et al.'s histologic scoring system. These scores were not significantly different between the irradiated segments. Inflammation and fibrosis scores for the anastomoses were also not significantly different. These results indicate that, in rats, anastomotic healing is impaired only when both limbs of the anastomosed intestine are irradiated. The normal strength of the anastomosis with only one limb irradiated cannot be explained by differences in inflammation, fibrosis, or radiation damage and is caused by an undetermined factor.

Anastomosis, Surgical↗
PubMed1992

Rhinocerebral mucormycosis: an unusual case presentation.

Rhinocerebral mucormycosis is a rapidly fatal fungal disease which involves the nose, paranasal sinuses, orbit and central nervous system. The fungal infection is usually secondary to immunosuppression, diabetic acidosis, or antibiotic, steroid or cytotoxic therapy. It can also occur in patients suffering from burns, malignancy and haematological disorders. Current treatment consists of correction of the underlying disorder, repeated debridement of the wound in combination with intravenous amphotericin B. This paper describes our experience with a case of rhinocerebral mucormycosis. This is an unusual case in which mucormycosis was seen in a young female where no underlying cause was found. She responded to surgical debridement in combination with intravenous amphotericin B.

Adult↗
PubMed1992

Deficiency in major high molecular-weight seminal proteins in men producing poorly coagulating and alkaline liquid ejaculates.

Using SDS-PAGE three major high molecular-weight coagulum proteins (57, 75 and 79 kD) were identified in unliquefied human ejaculates. Washed coagulum was prepared at pH 4.5 and demonstrated negligible proteolysis as determined by a highly sensitive fluorescamine-based method. Laser densitometric scanning of these high molecular-weight proteins in unliquefied ejaculates in relation to their coagulational failure revealed that the total content of 57, 75 and 79 kD proteins in whole semen represented approximately 44% of levels in the normally coagulated, approximately 24% in poorly coagulated (P less than 0.005) and approximately 3% in the non-coagulated (alkaline liquid, P less than 0.001) samples. The findings imply that these predominant high molecular-weight proteins play a major role in human seminal coagulum formation.

Adult↗
PubMed1992

Serum total bile acid concentration in rhesus monkeys: effects of feeding cholesterol and inhibiting cholesterol absorption and synthesis.

The serum total bile acid concentration was measured in rhesus monkeys fed diets practically free of cholesterol and with added cholesterol at two levels. Also, the effects of inhibiting cholesterol absorption by feeding plant sterols and inhibiting cholesterol synthesis by feeding triparanol upon the serum total bile acid levels were studied. Cholesterol feeding significantly increased the serum bile acid concentration. The serum bile acid level was decreased in the high responders fed plant sterols but only when the diet contained the highest level of cholesterol. In both groups serum bile acid levels were not altered when cholesterol biosynthesis was inhibited by feeding triparanol. It is suggested that cholesterol feeding increases the serum bile acid level probably due to an increase in the intestinal pool of bile acids as a result of increased production of bile acids in the liver and their excretion into the bile.

Animals↗
PubMed1991

Laser flash photolysis studies of the reduction kinetics of NADPH:cytochrome P-450 reductase.

The reduction kinetics of NADPH:cytochrome P-450 reductase have been investigated by the laser flash photolysis technique, using the semiquinone of 5-deazariboflavin (5-dRfH.) as the reductant. Transients observed at 470 nm at neutral pH indicated that the oxidized reductase was reduced via second-order kinetics with a rate constant of 6.8 X 10(7) M-1 s-1. The second-order rate constant corresponding to the formation of the protein-bound semiquinone (measured at 585 nm) was essentially the same as that obtained at 470 nm (7.1 X 10(7) M-1 s-1). Subsequent to this rapid formation of protein-bound semiquinone, a partial exponential decay was observed at 585 nm. The rate of this decay remained invariant with protein concentration between pH 5.0 and 7.0, and a first-order rate constant of 70 s-1 was obtained for this process. This is assigned to intramolecular electron transfer from FADH. to FMN. Prior reduction of the enzyme to the one-electron level led to a decrease in both the second-order rate constant for reduction (2 X 10(7) M-1 s-1) and the first-order intraflavin electron transfer rate constant (15 s-1). The protein-bound FAD moiety of FMN-depleted reductase was reduced by 5-dRfH. with a second-order rate constant that was identical with that observed with the native enzyme (6.9 X 10(7) M-1 s-1). However, with this species no significant decay of the FAD semiquinone was observed at 585 nm following its rapid formation, consistent with the above assignment of this kinetic process.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Prolactin and alpha-1,4-glucosidase activity in normal and poorly coagulated human semen.

Prolactin and alpha-1,4-glucosidase levels in seminal plasma were measured in poorly coagulated (I), deficiently coagulated (II) and normally coagulated (III and IV) human ejaculates having 0-20%, 21-50% and 51-100% coagulum respectively 4 min after emission. The prolactin concentration (ng ml-1, mean +/- SEM) in poorly coagulated (5.2 +/- 0.48) and deficiently coagulated (7.6 +/- 0.72) samples was significantly lower than in the normally coagulated groups III (51-75% coagulum, 8.2 +/- 0.43) and IV (76-100% coagulum, 9.9 +/- 0.59) as well as the presumably fertile samples (9.2 +/- 0.74). A highly significant positive correlation was observed between the prolactin level and the percentage coagulum of the ejaculates (r = 0.686, n = 58, P less than 0.001). In contrast, the epididymal marker, alpha-glucosidase showed no relationship to seminal coagulation.

Adult↗
PubMed1990

Changes in plasma lipoprotein concentrations and compositions upon feeding cholesterol in high- and low-responding rhesus monkeys.

When fed cholesterol, the high-responding rhesus monkeys develop severe hypercholesterolemia, whereas low-responding rhesus monkeys show only slight increases in plasma cholesterol levels. We report changes in plasma lipoprotein concentrations and compositions along with changes in plasma lipid concentrations in high- and low-responding rhesus monkeys fed a high-cholesterol diet. On low-cholesterol diet, the concentrations and compositions of plasma lipoprotein fractions were similar in the two groups. Upon feeding cholesterol, plasma very-low-density (VLDL), intermediate-density (IDL) and low-density (LDL)-lipoprotein concentrations increased in both groups, but the increases were significantly (p less than 0.01) higher in high-responders than in low-responders. Plasma HDL concentration decreased significantly (p less than 0.01) in high responders but not in low responders. In high responders, percent cholesterol increased in both VLDL and IDL fractions but in low responders, it decreased in VLDL and increased in IDL. Percent triglycerides decreased in VLDL, IDL and LDL fractions in high responders, while in low responders it tended to increase in VLDL, remained unchanged in IDL and decreased in LDL. The composition of HDL did not change in the two groups upon feeding cholesterol. Thus, when fed cholesterol, the high- and the low-responding monkeys respond distinctly differently in plasma lipoprotein concentrations and compositions. The responses occurred simultaneously, suggesting metabolic interrelationships between various lipoproteins.

Animals↗
PubMed1990

Biochemical composition of washed human seminal coagulum in comparison to sperm-free semen from the same donors.

Intra-individual inter-ejaculate variations in the amounts of protein, fructose, N-acetylamino sugar, phosphate, sialic acid and amino sugar in washed coagulum from normal ejaculates of men were highly consistent (N = 9). All the prostatic components studied (acid phosphatase, zinc, calcium and citric acid), except zinc, in the washed coagulum were reduced by 90% of their values in semen (N = 5). The seminal vesicular markers (fructose, N-acetylamino sugar and phosphate) had no association with the coagulum structure and represented the soluble components (N = 5). The concentrations of protein and zinc in the coagulum were higher than those of semen by 114% and 32% respectively. The coagulum contained sialic acid and amino sugar as integrated components.

Acid Phosphatase↗
PubMed1990

Kwashiorkor and marasmus: changing hospital incidence of syndromic presentation (1957-88).

This clinico-epidemiological study was undertaken to substantiate the impression that the pattern of clinical presentation of protein-energy malnutrition causing kwashiorkor-marasmus syndrome (KMS) is changing over time. An analysis of data for the period 1964-88, obtained from the specialised Pediatric Clinic of the Calcutta School of Tropical Medicine serving mostly the city slums showed decrease (p less than 0.01) in the incidence of chronic edematous forms of severe KMS, less decrease (p less than 0.05) in the incidence of mild-moderate KMS and increase (p less than 0.01) in the incidence of nutritional marasmus and of chronic very severe forms of KMS characterised by extreme retardation in growth and development. Incidentally, a rising incidence of rickets was observed. In the hospitalised cases (1957-88) these observations were corroborated. Data for 1985-88 of NRS Medical College Hospital, Calcutta, a general hospital serving the city as well as the neighbouring rural areas, showed that among the hospitalised city children edematous KMS was proportionately fewer than marasmus. The situation was reverse in the children from the rural areas. The observations suggested that the syndromic presentation of KMS is changing over the last three decades with some rural-urban differences for which only some recent data could be available.

Child↗
PubMed1989

Differences in fecal excretion of cholesterol and bacterial degradation products in high- and low-responding rhesus monkeys: implications in colon cancer.

This paper reports the differences in the fecal excretion of cholesterol and its degradation products in high- and low-responding rhesus monkeys fed diets with and without extra cholesterol. The high-responding monkeys had a great increase in plasma cholesterol concentration when fed a high-cholesterol diet, whereas the low-responders had a small increase when fed the same diet. The results show that low-responding monkeys, when fed high-cholesterol diets, excrete nearly two to three times the amount of cholesterol and its bacterial degradation products in the feces than the high-responding monkeys. We suggest that these two select groups of monkeys may be useful models for the study of the role cholesterol and its bacterial degradation products play in colon cancer.

Animals↗
PubMed1989

Fatty acid composition of adipose tissue in humans: differences between subcutaneous sites.

We compared the fatty acid composition of adipose tissue from three different sites, one deep-seated site (perirenal) and two subcutaneous sites (abdominal and buttock), in 143 autopsied adult humans aged 24-61 y. The proportion of saturated fatty acids was highest in the perirenal adipose tissue and lowest in buttock adipose tissue. The proportions of monounsaturated fatty acids in the three sites were in the reverse order. Linoleic and linolenic acids were similar in the three adipose-tissue sites, an important finding for those concerned about the essential fatty acids, which are solely derived from the diet. The results clearly show that the fatty acid composition of the two subcutaneous fat depots differ significantly. We conclude that abdominal fat is more saturated than buttock fat.

Abdomen↗
PubMed1989

Cyclic changes in salivary lactate dehydrogenase, peroxidase and leucine aminopeptidase during menstrual cycle.

Salivary lactate dehydrogenase (LDH), peroxidase (Px) and leucine aminopeptidase (LAP) activities were scanned in both normally ovulating and anovulating women during entire menstrual cycle. In ovulating women, all the three enzymes exhibited significant increase in the activity on or before the onset of ovulation which was monitored by the shift of the basal body temperature (BBT) as well as the ferning pattern of the cervical mucus. The peak maximum at the midcycle was several times higher than the previous day value in all the six normal women. In anovulatory women, no such remarkable change in the enzyme activities was found throughout the cycle. Salivary LDH and LAP showed peak at the midcycle and at the same time required short time for assay, so the present results are strongly suggestive that the determination of salivary enzyme content may be a convenient method for detecting the day of ovulation.

Female↗
PubMed1989

Factors regulating plasma cholesterol concentration.

Plasma cholesterol concentration in humans and animals is held at remarkably constant level under constant dietary condition. Critical reevaluation of our studies indicated that cholesterol absorption and fecal excretion rather than cholesterol synthesis play major role in regulating plasma cholesterol concentration in high- and low-responding rhesus monkeys. The high-responding monkeys are those who respond with mild increase in plasma cholesterol when fed high cholesterol diet while the low-responding monkeys are those who respond with mild increase in plasma cholesterol when fed an identical high cholesterol diet. Humans also respond differently when fed high cholesterol diet, i.e., there are high- and low-responding humans. I suggest that in humans also cholesterol absorption and fecal excretion rather than cholesterol synthesis play greater roles in the regulation of plasma cholesterol concentration.

Animals↗
PubMed1989

Structural changes in human cervical mucus.

The crystallization phenomenon of human cervical mucus was investigated with the help of scanning electron microscope. Changes in the conformation of crystals and ferning patterns were studied on different days of the menstrual cycle in both normally ovulating women and those using oral contraceptives. No crystalline structure was found on day 5 in both categories of women, whereas square crystals were observed on day 21 in normal woman. Nature and type of ferning pattern changes seen from days 11 to 14 in normal women were not seen during this period in women who were on oral contraception, instead a thick, viscous mucus was found during the entire period of the cycle.

Adult↗
PubMed1989

Glycerylphosphorylcholine levels in the coagulational groups of human ejaculates.

The amount of coagulum present in fresh ejaculates of men (among infertile couple) varied directly with the levels of seminal glycerylphosphorylcholine (GPC; P less than 0.001), which is secreted predominantly by the epididymis. GPC concentrations (mg/ml) of the normally and poorly coagulating ejaculates revealed close similarities with those of the presumably fertile (1.72 +/- 0.10) and infertile semen (1.13 +/- 0.08) respectively. The study suggests that the degree of coagulation of human ejaculates may be correlated with epididymal function.

Adult↗
PubMed1988

Studies on the mechanism of high intestinal absorption of cholesterol and campesterol in high-responding rhesus monkeys.

To understand better the mechanism of higher absorption of cholesterol and campesterol in high-responding than in low-responding rhesus monkeys, we measured the concentrations of the two sterols in the micellar fraction isolated from small intestinal content, and also determined their rates of esterification by cholesterol esterase prepared from the small intestinal mucosa. The results show that the concentrations of both cholesterol and campesterol in the micellar fraction were significantly higher in the high- than in low- and intermediate-responding rhesus monkeys. Also the rates of esterification of both sterols are higher in the proximal segment of the small intestine in high-responders than the other two groups. We conclude that the two necessary steps in the process of sterol absorption, namely, the amounts of sterols solubilized in micelles and their esterification within mucosal cells which are higher in high- than in low-responders are responsible for the higher absorption of the sterols in the high-responding rhesus monkeys.

Animals↗