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H Das

Publications and source records attributed to H Das.

35 records · Page 2Linked to original sources
PubMed1994

Pharmacokinetics and metabolism of diclofenac sodium in Yucatan miniature pigs.

The pig has been suggested as an animal model in biomedical research because of its physiological similarity to man. Therefore, the pharmacokinetics and metabolism of diclofenac sodium (Voltaren) were studied in four Yucatan minipigs after intravenous administration of 25 and 50 mg and oral administration of 50 mg in a solution of 50 mL buffer, 50 mL water, and 200 mL water, and the results compared to historical data in man. The absolute bioavailability after oral administration of 50 mL buffer, 50 mL water, and 200 mL water solutions were 107, 97, and 109%, respectively, compared to approximately 50% in man. The total plasma clearance in minipigs was fivefold slower than in humans (57 +/- 17 vs 252 +/- 54 mL/hr/kg). The plasma levels of the metabolites 4'-hydroxy, 5-hydroxy, 3'-hydroxy, 4',5-dihydroxy, and 3'-hydroxy-4'-methoxy diclofenac were considerably lower in minipigs than in man after both i.v. and oral administration. These results suggest slower metabolism and/or enterohepatic recirculation of the parent drug in minipigs. The volume of distribution of the central compartment was 40% less in humans than in pigs (39 vs 67 mL/kg). The terminal half-lives of the parent drug were similar in pigs (2.4 hr) and humans (1.8 hr). The rate of oral drug absorption increased in the order of 50 mL aqueous, 200 mL aqueous, and 50 mL buffered solutions (Ka = 0.52 +/- 0.11, 0.59 +/- 0.13, and 1.2 +/- 0.7 hr-1, respectively). These trends are similar in man and suggest that both buffering and intake volume can affect diclofenac absorption.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1993

Evaluation of 'cypenhymustine', a new anticancer compound, in murine tumour models.

'Cypenhymustine', 3-[2-[bis(2'-chloroethyl)-amino] ethyl]-5,5- tetramethylenehydantoin, has been synthesised as a potential analog of spiromustine (NSC 172112). The LD50 value was determined in Swiss male mice and found to be 65.0 mg/kg by single i.p. injection. In in vivo screening experiments, three parameters, namely, ascites cell count, ascites fluid measurement and increase in life span (ILS) of drug-treated over control Swiss mice were studied in three murine ascites tumours namely Ehrlich ascites carcinoma (EAC), sarcoma-180 (S-180) and Dalton's lymphoma (DL). Cypenhymustine exhibited a very high percentage of inhibition of both the ascites cell and fluid in these models and also displayed excellent reproducible ILS activity (ILS values of 151 in EAC, 157 in S-180 and 181 in DL at the optimum dose of 3 mg/kg for days 1-7 treatment following tumour transplant on day 0) having a 'curative' effect (1-2 animals: 6 having > 60 days survival rate). The chemical alkylating activity has been compared with spiromustine and another antitumour agent namely nor-HN2.

Animals↗
PubMed1993

Evaluation of 2-(methylaminosulfonyl)-1-(arylsulfonyl)-1-methylhydrazines as anticancer agents.

Seven new 2-(methylaminosulfonyl)-1-(arylsulfonyl)-1-methylhydrazines were prepared. The anticancer activity of these compounds was assessed in murine Ehrlich ascites carcinoma (EAC) by in vivo screening. Moderate in vivo activity in EAC was exhibited by three compounds. All of them were screened in vitro against a battery of human tumor cell lines at the National Cancer Institute (NCI), USA. One of them, compound 3a has displayed highly significant specificity in the renal tumor cell line RXF 393. These three compounds were also assessed for in vitro anti-HIV activity at the NCI, however, they have not reached the criteria of significant activity. The alkylating activity of the compounds was determined by measuring the absorbance of the alkylated product of 4-(4-nitrobenzyl)pyridine. It has been found that they are capable of acting as chemical alkylating agents.

Animals↗
PubMed1982

Isolation of a cDNA clone for the human HLA-DR antigen alpha chain by using a synthetic oligonucleotide as a hybridization probe.

We have used a synthetic 20-nucleotide hybridization probe to isolate a cDNA clone encoding the alpha chain of the HLA-DR antigen from a cDNA library constructed from membrane-bound poly(A)+ mRNA. A set of synthetic 11-nucleotide fragments, potentially complementary to the codons for amino acids 11-14 of the HLA-DR alpha chain, were used to prime a cDNA synthesis reaction on various poly(A)+ mRNA templates. Extension of the primers in the presence of a single dideoxynucleotide triphosphate resulted in an 18-nucleotide cDNA product whose sequence corresponded to the NH2-terminal amino acids of the HLA-DR alpha chain. An oligonucleotide was synthesized based on this sequence information and its specificity for HLA-DR alpha mRNA was confirmed by primer extension and blot analysis. The cDNA library made from mRNA from the lymphoblastoid cell line CA-SC was probed with 32P-labeled cDNA synthesized on poly(A)+ mRNA from a B-cell line (CA-SC) or from a T-cell line (Molt-4) to enrich for B-cell-specific clones. A set of cDNA clones that hybridized preferentially with the B-cell probe was screened with the 32P-labeled 20-nucleotide probe. The cDNA clone isolated by this procedure is 1,100 nucleotides long; the nucleotide sequence of the 5' end of the cDNA insert corresponds to the amino acid sequence of the HLA-DR alpha chain. Hybridization of this cDNA clone to genomic blots suggests that the HLA-DR alpha chain is encoded by a single-copy gene. One of the restriction endonucleases used in genomic DNA digests reveals a restriction fragment polymorphism.

Amino Acid Sequence↗
PubMed1979

Protein synthesis in rabbit reticulocytes: characteristics of a postribosomal supernatant factor that reverses inhibition of protein synthesis in heme-deficient lysates and inhibition of ternary complex (Met-tRNAfMet.eIF-2.GTP) formation by heme-regulated inhibitor.

During heme deficiency in reticulocyte lysates, a translational inhibitor (heme-regulated inhibitor, HRI) that blocks polypeptide chain initiation is activated. HRI is a protein kinase that specifically phosphorylates the 38,000-dalton subunit of the Met-tRNAfMet binding factor, eIF-2. Phosphorylation of eIF-2 by HRI prevents its interaction with at least two additional factors, resulting in a net reduction in formation of ternary complex (Met-tRNAfMet.eIF-2.GTP) and AUG-dependent transfer of Met-tRNAfMet to 40S ribosomal subunits. A factor (sRF) that reverses protein synthesis inhibition in heme-deficient lysates has been purified from reticulocyte postribosomal supernatant. sRF also reverses the inhibition of ternary complex formation by HRI in a fractionated system. The ternary complex inhibition reversal activity and the protein synthesis inhibition reversal activity cosediment at 12.5 S upon glycerol density gradient centrifugation, and both activities are sensitive to heat or N-ethylmaleimide. Purified sRF does not dephosphorylate eIF-2 whose phosphorylation has been catalyzed by HRI, nor does the sRF prevent the phosphorylation of eIF-2 by HRI in a fractionated system. sRF stimulates ternary complex formation by both phosphorylated and nonphosphorylated eIF-2. These observations suggest that the sensitivity of protein synthesis to phosphorylation of eIF-2 by HRI may be modulated by the concentration and activity of sRF.

Animals↗
PubMedDate not supplied

Role of aprotinin in the management of experimental fungal keratitis.

In an experimentally induced Aspergillus fumigatus fungal keratitis in 20 rabbits, aprotinin, an antiplasmin agent, was studied to find out its role as an adjuvant when given along with other established antifungal agents like natamycin and fluconazole. The 20 rabbits included in this study were randomly divided into four equal treatment groups. Once the ulcer was produced after intrastromal injection of 0.03 ml of A. fumigatus (5.5 x 10(4) spores/ml), different drugs/agents in combination were used in a randomized manner. These were natamycin (5%) + placebo, natamycin + aprotinin (40 IU/ml), fluconazole (0.3%) + placebo and fluconazole + aprotinin. The rabbits were followed up every day to note the signs of healing which included subsidence of corneal infiltration, disappearance of stromal abscess and subsidence of corneal oedema till complete healing. Results showed that the average healing time was 28.2, 28.4, 49.8 and 49.0 days for natamycin + placebo, natamycin + aprotinin, fluconazole + placebo and fluconazole + aprotinin, respectively. It suggests that aprotinin as an adjuvant has no definite role in the management of fungal keratitis. The plasminogen activator-plasmin system which is inhibited by aprotinin may not be the pathway through which filamentous fungi like A. fumigatus cause tissue destruction.

Animals↗
PubMedDate not supplied

Changes in biochemical markers of hyperplastic and malignant prostatic tissues.

Some biochemical markers were evaluated in human prostatic tissue obtained from patients with benign hyperplasia. There was an almost threefold increase in the activity of acid phosphatase of these patients as compared to that of normal men. The changes in the acid phosphatase activity were directly correlated with citric acid concentration. Significant (p less than 0.001) increases in the content of citric acid, zinc, and calcium in benign hyperplastic prostates was found. There was no change in the activity of aminopeptidase. The activities of both enzymes were lower in malignant prostatic tissues.

Biomarkers, Tumor↗
PubMedDate not supplied

Endoscopic sclerotherapy in children with extrahepatic portal venous obstruction.

BACKGROUND: Extrahepatic portal vein obstruction (EHPVO) is a common cause of variceal bleeding in children in India. There is paucity of data regarding the results of treatment with endoscopic sclerotherapy. METHODS: Fifty-nine children (mean age 11 +/- 3.8 years; range 7 months to 12 years; 36 males and 23 females) were studied from February 1990 to September 1999. EHPVO was diagnosed on the basis of portal cavernoma on ultrasonography in 55 patients and on splenoportovenogram in 4 patients. Endoscopic sclerotherapy was caried out at weekly intervals for the first three weeks and at 3 weekly intervals thereafter till complete or near complete thrombosis was achieved. All patients were followed up with check endoscopy every 3-6 months after thrombosis of oesophageal varices. RESULTS: Over a mean follow up of 25.4 months (range 3 to 87 months) total thrombosis was achieved in 53 (89.8%) of 59 children. The mean number of sclerotherapy sessions required were 7.5 +/- 2.2. The mean number of blood transfusions required per bleeding episode was 3.8 +/- 3.2. Of the 59 children 21 (35.6%) rebled, of which 17 (28.8%) bled during and 4(6.8) after thrombosis of varices. Seven (11.9%) children had more than one episode of bleeding. Once thrombosis of the varices was achieved 15 (26%) of 59 children developed fresh varices on follow up. Gastric varices were detected in 47 (60%) children. In 39 (66%) children it was present at the onset and in 8 (13.5%) children it developed after thrombosis of oesophageal varices. Bleeding from gastric varix occurred in 7(9%) children. Ascites developed in 6(10.6%) children. One child developed oesophageal stricture. There were 3 (5%) deaths. Two died due to upper gastrointestinal bleed while on sclerotherapy schedule and one died due to cerebral abscess. CONCLUSION: EHPVO is an important and common cause of upper gastrointestinal bleeding in children in Western India. EST is safe and useful in controlling oesophageal variceal bleeding in children.

Child↗
PubMedDate not supplied

Pattern of intraocular pressure changes following manual small incision cataract surgery.

OBJECTIVES: To find out the pattern of changes in intraocular pressure after manual small incision cataract surgery. METHODS: Consecutive patients (291 eyes of 291 patients) undergoing manual small incision cataract surgery were prospectively evaluated for change in IOP. Patients were further divided into two groups based on whether or not sutures were used to close the scleral tunnel. IOP was serially measured at day 1, 1st, 2nd, 4th, 6th, 8th and 12th week. RESULTS: The mean post operative IOP in eyes where sutures were not applied (12.59+/- 3.02 mmHg, 12.59+/-2.34mmHg, 12.54+/-2.19mmHg and 12.40+/-2.99 mm Hg at day1, 2week and 4weeks respectively) was lower than that where sutures were used to close the wound (15.57+/- 3.86mmHg, 14.05+/-2.52mmHg, 14.43+/-3.39mmHg at day1, 2weeks and 4 weeks respectively). There was a drop of IOP from the preoperative IOP in both suture (1.15+/-3.29mm Hg) and non suture (3.29+/-3.07mm Hg) group at 3 months of follow up. CONCLUSION: There is a small drop of IOP following sutureless MSICS during long term follow up. Eyes where sutures are applied are more likely to have higher IOP than those without sutures at the initial post operative period.

Cataract Extraction↗
PubMedDate not supplied

Vegetative tissue lectins of peanut (A. hypogaea).

Lectin activities in roots, nodules, stems and leaves of 1-6 week old peanut plant (A. hypogaea) were checked by erythrocyte (human and rabbit) agglutination and sugar inhibition assays. Human and rabbit erythrocyte agglutinating activities were specifically inhibited by lactose/cellobiose (SLII) and methyl alpha-mannoside (SLI) respectively. Seeds, embryos and cotyledons agglutinated neuraminidase treated human erythrocytes and that activity was inhibited by T-disaccharide. In the roots of field grown plants SLI was the major activity, while nodules showed both activities (SLI and SLII). Specific activities of SLI and SLII were maximal in stem tissue and hypocotyl exhibited minimal levels. Actively growing tissues like newly emerging young leaves and elongating stem contained more SLII activity in comparison to the mature tissues. Immunological test indicated that all the vegetative tissue lectins are serologically related.

Animals↗