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Biomedical subjects

A K Das

Publications and source records attributed to A K Das.

At least 37 records · Page 2Linked to original sources
PubMed2003

Comparative evaluation of grading of breast carcinomas in fine needle aspirates by two methods.

BACKGROUND & OBJECTIVES: Fine needle aspiration (FNA) material is increasingly being used to determine various prognostic parameters in patients with carcinoma breast. It was recommended that cytological grading should be part of all FNA reports of breast carcinoma so that preoperative prognostication could be done on it. However, the most reliable method for cytological grading that closely reflects the most widely used histological grading system is yet to be determined. This study was undertaken to compare results of two cytological grading methods to see which corresponded better to the histological grade. METHODS: In a double-blind study, cytological grading of 52 patients with breast carcinoma was carried out using two different grading systems (Robinson's and Mouriquand's methods) and the grades compared with the histological grading to find out which reflected histological grades more closely. RESULTS: By Robinson's method 28.8, 46.2 and 25 per cent aspirates were graded as I, II and III respectively. Using Mouriquand's grading 9.6, 69.2 and 21.2 per cent aspirates were graded correspondingly. Comparison of the two methods showed a concordance in 40 (76.9%) cases. Both cytological grading systems showed a concordance of 71.2 per cent with the histological grading. Robinson's cytological grading showed a diagnostic accuracy of 80.76 per cent with 77.77 per cent specificity while Mouriquand's method had an accuracy of 84.60 per cent with 33.33 per cent specificity. INTERPRETATION & CONCLUSION: Though the Robinson's and Mouriquand's grading systems were found to have similar concordance with histological grading, Robinson's method was considered better because of its simplicity, and specificity.

Biopsy, Fine-Needle↗
PubMed2002

Effect of Trichodesma indicum extract on cough reflex induced by sulphur dioxide in mice.

The effect of methanol extract of whole plants of Trichodesma indicum R. Br. has been investigated on sulphur dioxide (SO2) induced cough reflex in Swiss albino mice. The extract has demonstrated significant (p < 0.001) inhibition in frequency of cough in all the tested doses when compared with untreated control group. The effect persisted up to 90 min of its oral administration and also comparable to that of the effect exhibited by the standard drug (Codeine phosphate). This study confirmed the traditional use of this plant in the treatment of cough. Determination of underlying mechanism of beneficial effect is major topic requiring further comprehensive investigation.

Administration, Oral↗
PubMed2002

GAD65 and ICA512 antibodies in undernourished and normally nourished south Indian patients with diabetes.

The frequency of GAD65 and ICA512 antibodies in Indian IDDM patients is similar to that in Caucasians. The aim of the study was to test whether undernutrition is associated with autoimmunity as evidenced by increased or decreased autoantibody formation in both clinically diagnosed IDDM and NIDDM patients from south India. The prevalence of GAD65 and ICA512 autoantibodies in controls from south India was 4% and 2%, respectively. One hundred thirty-one diabetic patients (undernourished [UNDM], n = 67; and normal nourished [NNDM], n = 64) were assayed for GAD65 and ICA512 autoantibodies. None were obese. All patients were new onset or with duration <5 years. GAD65 autoantibodies were present in 73/131 (55%), and ICA512 antibodies were present in 43/131 (33%) of patients. The results suggest that GAD65 and ICA512 antibody frequencies are neither significantly increased nor decreased in UNDM patients compared to NNDM patients. In addition, the increased frequency of autoantibodies among NIDDM compared to IDDM in both nutrition groups suggests high prevalence of slow-onset IDDM. In conclusion, undernutrition does not predispose to autoimmunity in south Indian diabetic patients.

Autoantibodies↗
PubMed2002

Discriminatory value of blood urea:creatinine ratio in upper gastrointestinal bleeding with and without cirrhosis of liver.

AIM: To evaluate the discriminatory ability of blood urea:creatinine ratio in upper gastro-intestinal bleeding (UGIB) with and without cirrhosis of liver. METHODS: Blood urea:creatinine (BU/CR) ratio in 160 adult patients of UGIB were studied after excluding clinically overt cirrhosis of liver, renal failure and hematochezia. All were subjected to ultrasonography of abdomen. Only those showing cirrhosis and portal hypertension (n=76) were taken up for liver biopsy to confirm the diagnosis. BU/CR ratio was compared to UGIB cases without cirrhosis of liver (n=84). RESULTS: The mean (+/- SD) blood urea creatinine ratio was significantly lower in the group with cirrhosis than without cirrhosis of liver (22.49 +/- 6.13 vs. 38.07 +/- 8.08, Z value 13.91). CONCLUSION: In absence of renal failure, the blood urea/creatinine ratio may differentiate UGIB with associated cirrhosis of liver from those without. Being simple, cheap and readily available, it can be of some value in those patients with cirrhosis of liver clinically not associated with gross findings of cirrhosis. In our study it was also noted that, an arbitrary cut-off value of 30 showed considerable overlap between the two groups; hence this ratio may not always differentiate between the cirrhotics and non-cirrhotics. Therefore, reproducibility of these results needs further studies, taking into account other factors which can modify the BU level in our population.

Adult↗
PubMed2002

Problem of timely diagnosis in anthrax meningitis.

Anthrax continues to remain a problem in parts of India. Meningitis is often a complication encountered among cases with cutaneous anthrax. We have encountered a dozen cases of anthrax meningitis in our hosptal in the past decade. A sudden unexplained rise in cases in the past two years with hundred percent mortality stresses the need for rapid confirmatory diagnosis. Most of the cases admitted with central nervous system involvement had a provisional diagnosis of conditions other than anthrax meningitis. A strong clinical suspicion with a simple Gram stain smear of the CSF will help confirm anthrax meningitis in endemic areas.

Adult↗
PubMed2002

Chorea due to nonketotic hyperglycemia.

A 62 year old diabetic and hypertensive male presented with sudden onset generalized chorea. Investigations revealed uncontrolled diabetes with absent ketones and normal serum osmolality. Achievement of euglycemia with insulin therapy abolished the involuntary movements completely within a day. The direct effect of hyperglycemia causing striatal neuronal dysfunction could be the pathogenesis of the chorea in our patient.

Chorea↗
PubMed2002

Acanthameba meningoencephalitis: a case report.

A 45 year old lady presented with history of recent surgery for uterovaginal prolapse and retained vaginal tampons following which she developed chronic meningitis due to acanthameba infection. Patient responded to a regimen containing albendazole. She was left with hydrocephalus as a sequelae.

Acanthamoeba↗
PubMed2002

Potentiality of a new compound for in vitro differentiation between halophilic and non-halophilic vibrios.

Sensitivity of 21 halophilic vibrios and 16 clinical isolates of non-halophilic vibrios was determined against a new possible antivibrio agent, a pyrimidine analogue, 4, 6-dimethylpyrimidine -2-thiol (4,6-DMPT). It appeared to be a vibriocidal agent, having a mean MIC and MBC of 32 microg/ml for halophilic strains and 64 microg/ml for non-halophilic strains and an LD50 of 300 mg/Kg body weight of mice. Thus, 4,6-DMPT may help an in vitro distinction between halophilic and non-halophilic vibrios. Sensitivity of these strains was also studied with respect to pteridine, crystal violet and Tween 80 hydrolysis as further markers distinguishing between these 2 groups which could also be differentiated by their growth on TCBS or/and CLED media.

Animals↗
PubMed2001

Crystal structure of the tumor-promoter okadaic acid bound to protein phosphatase-1.

Protein phosphatase-1 (PP1) plays a key role in dephosphorylation in numerous biological processes such as glycogen metabolism, cell cycle regulation, smooth muscle contraction, and protein synthesis. Microorganisms produce a variety of inhibitors of PP1, which include the microcystin class of inhibitors and okadaic acid, the latter being the major cause of diarrhetic shellfish poisoning and a powerful tumor promoter. We have determined the crystal structure of the molecular complex of okadaic acid bound to PP1 to a resolution of 1.9 A. This structure reveals that the acid binds in a hydrophobic groove adjacent to the active site of the protein and interacts with basic residues within the active site. Okadaic acid exhibits a cyclic structure, which is maintained via an intramolecular hydrogen bond. This is reminiscent of other macrocyclic protein phosphatase inhibitors. The inhibitor-bound enzyme shows very little conformational change when compared with two other PP1 structures, except in the inhibitor-sensitive beta12-beta13 loop region. The selectivity of okadaic acid for protein phosphatases-1 and -2A but not PP-2B (calcineurin) may be reassessed in light of this study.

Carcinogens↗
PubMed2001

Biochemical analysis of mutations in palmitoyl-protein thioesterase causing infantile and late-onset forms of neuronal ceroid lipofuscinosis.

Deficiency in a recently characterized lysosomal enzyme, palmitoyl-protein thioesterase (PPT), leads to a severe neurodegenerative disorder of children, infantile neuronal ceroid lipofuscinosis (NCL). Over 36 different mutations in the PPT gene have been described, and missense mutations have been interpreted in the light of the recently solved X-ray crystallographic structure of PPT. In the current study, we assessed the biochemical impact of mutations through the study of cells derived from patients and from the expression of recombinant PPT enzymes in COS and Sf9 cells. All missense mutations associated with infantile NCL showed no residual enzyme activity, whereas mutations associated with late-onset phenotypes showed up to 2.15% residual activity. Two mutations increased the K(m) of the enzyme for palmitoylated substrates and were located in positions that would distort the palmitate-binding pocket. An initiator methionine mutation (ATG-->ATA) in two late-onset patients was expressed at a significant level in COS cells, suggesting that the ATA codon may be utilized to a clinically important extent in vivo. The most common PPT nonsense mutation, R151X, was associated with an absence of PPT mRNA. Mannose 6-phosphate modification of wild-type and mutant PPT enzymes was grossly normal at the level of the phosphotransferase reaction. However, mutant PPT enzymes did not bind to mannose 6-phosphate receptors in a blotting assay. This observation was related to the failure of the mutant expressed enzymes to gain access to 'uncovering enzyme' (N-acetylglucosamine-1-phosphodiester alpha-N-acetyl glucosaminidase), presumably due to a block in transit out of the endoplasmic reticulum, where mutant enzymes are degraded.

Age of Onset↗
PubMed2001

9(R)-[6(R)-hydroxymethyl-1-oxa-4-thiacyclohexan-2-yl]hypoxanthine-water (4/3), a nucleoside analogue.

The title compound, 9(R)-[6(R)-hydroxymethyl-1-oxa-4-thiacyclohexan-2-yl]-1,9-dihydro-6H-purin-6-one-water (4/3), C10H12N4O3S-0.75H2O, crystallizes in the triclinic space group P1 with four molecules in the asymmetric unit and 0.75 waters of hydration per molecule. The structure was refined to an R value of 0.072 for 3382 observed reflections. The four crystallographically independent molecules are designated A, B, C and D. All four oxathiane rings adopt the chair conformation and the purine bases are in an anti orientation with respect to the sugar moieties. Molecules A and D and molecules C and B are base paired by a single hydrogen bond of the type N-H...N. These base pairs are again hydrogen bonded to their translated pairs in the direction of a cell diagonal.

Antiviral Agents↗
PubMed2001

The effect of urine volume and nitric oxide on basal bladder blood flow: response to catheterization and drainage.

Preliminary studies demonstrated that catheterization and drainage of the urinary bladder resulted in a significant increase in blood flow to the bladder. The objectives of this study were to determine 1) the relationship between urine volume and basal blood flow to the bladder smooth muscle and mucosa, 2) the effect of acute catheterization and drainage on bladder mucosal and smooth muscle blood flow, and 3) whether nitric oxide was involved in regulation of basal blood flow or the increase in blood flow observed after catheterization and bladder drainage. Twenty-four rabbits were separated into two groups: group 1 (14 rabbits) and group 2 (10 rabbits) treated with L-NAME (NOS inhibitor) 30 minutes before blood flow measurement. Blood flow was measured in all animals using a fluorescent microsphere technique before and immediately after catheterization and drainage of the bladder. The results demonstrated that 1) blood flow to the muscle and mucosa were independent of urine volume at the time of catheterization and drainage; 2) catheterization and drainage significantly increased blood flow to both the bladder smooth muscle and bladder mucosa, but not to the kidney; 3) L-NAME significantly reduced basal blood flow to the kidney, but not to the bladder smooth muscle or mucosa; and 4) L-NAME completely prevented the catheterization- and drainage-induced increases in blood flow to the bladder body mucosa and muscle. This study demonstrates that basal blood flow to the bladder smooth muscle and mucosa during filling is independent of NO control; although bladder blood flow may be increased significantly by NO synthesis and release during bladder emptying, and thus may be an important regulator of blood flow during and immediately following micturition.

Animals↗
PubMed2001

Studies on the hypoglycaemic activity of Punica granatum seed in streptozotocin induced diabetic rats.

The hypoglycaemic activity of Punica granatum Linn. (Family Punicaceae) seed extract on rats made diabetic by streptozotocin (STZ) was investigated. The methanol extract of the seed at doses of 300 and 600 mg/kg, and chlorpropamide 200 mg/kg was administered to STZ diabetic rats. The seed extract (150, 300 and 600 mg/kg, orally) caused a significant reduction of blood glucose levels in STZ induced diabetic rats by 47% and 52%, respectively, at the end of 12 h.

Administration, Oral↗
PubMed2001

High prevalence of diabetes and impaired glucose tolerance in India: National Urban Diabetes Survey.

AIMS/HYPOTHESIS: There has been no reported national survey of diabetes in India in the last three decades, although several regional studies show a rising prevalence of diabetes. The aim of this study was to assess the prevalence of diabetes and impaired glucose tolerance in six major cities, covering all the regions of the country. METHODS: Using a stratified random sampling method, 11216 subjects (5288 men; 5928 women) aged 20 years or above, representative of all socio-economic strata, were tested by OGTT. Demographic, anthropometric, educational and social details were recorded using a standard proforma. Physical activity was categorised using a scoring system. Body mass index (BMI) and waist-to-hip ratio (WHR) were calculated. Glucose tolerance was classified using the 2-h values (WHO criteria). Prevalence estimations were made taking into account the stratified sampling procedure. Group comparisons were done by t-test or analysis of variance or Z-test as relevant. Univariate and multiple logistic regression analyses were used to study the association of variables with diabetes and impaired glucose tolerance. RESULTS: Age standardised prevalences of diabetes and impaired glucose tolerance were 12.1% and 14.0% respectively, with no gender difference. Diabetes and impaired glucose tolerance showed increasing trend with age. Subjects under 40 years of age had a higher prevalence of impaired glucose tolerance than diabetes (12.8% vs 4.6%, p < 0.0001). Diabetes showed a positive and independent association with age, BMI, WHR, family history of diabetes, monthly income and sedentary physical activity. Age, BMI and family history of diabetes showed associations with impaired glucose tolerance. CONCLUSIONS/INTERPRETATION: This national study shows that the prevalence of diabetes is high in urban India. There is a large pool of subjects with impaired glucose tolerance at a high risk of conversion to diabetes.

Adult↗