Biomedical subjects
A Gupta
Publications and source records attributed to A Gupta.
Selection of materials for ultraviolet-absorbing intraocular lenses.
Explore the source record for details and available documents.
Comparison of the effects of etomidate and thiopentone on intraocular pressure.
The effects of etomidate and thiopentone on intraocular pressure were studied in 50 patients of either sex undergoing routine non-ophthalmic surgery. Both drugs decreased intraocular pressure significantly. However, etomidate induced a significantly greater decrease in intraocular pressure than did thiopentone.
Spinal actions of substance P analogues on cardiovascular responses in the rat: a structure-activity analysis.
Ten substance P (SP) analogues were tested for their effects on mean arterial pressure and heart rate following intrathecal administration in the pentobarbital anaesthetized rat. The 10 analogues are [D-Pro4,D-alpha Npa7,9,10]SP(4-11) (A-I), (D-alpha Npa7,9,10]SP (A-II), [D-Trp7,9,10]SP (A-III), [D-Pro4,D-Npa7,9,Phe11]SP(4-11) (A-IV), [D-Pro4,D-beta Npa7,D-alpha Npa9,D-Phe11]SP(4-11) (A-V), [D-Pro4,Lys6,D-Trp7,9,10,Phe11]SP(4-11) (A-VI), [D-Pro4,D-Trp7,9,10,Phe11]SP(4-11) (A-VII), [D-Pro4,D-Trp7,9,10,Trp11]SP(4-11) (A-VIII), [D-Trp7,9,10,Trp11]SP (A-IX), and [D-Pro4,D-Phe7,9,10,Phe11]SP(4-11) (A-X). At 6.5 nmol, the analogues containing the amino acid D-Npa (A-I, A-II, A-IV, and A-V) or D-Phe (A-X) in positions 7, 9, or 10 of SP or its C-terminal octapeptide are devoid of the long-lasting cardio- and vaso-depressor effects, which are otherwise seen with analogues containing the amino acid D-Trp (A-III, A-VI, A-VII, A-VIII, and A-IX) in the same positions. Some of the analogues containing D-Npa maintain the initial hypotensive effect seen with SP while the analogue containing D-Phe produces only a small hypertensive response. The 10 analogues when tested at a dose that failed to alter basal mean arterial pressure and heart rate did not block the cardiovascular responses elicited by SP and no cross desensitization was observed between SP and these analogues. It appears that these SP analogues exert cardiovascular effects in the rat spinal cord probably without interacting with SP receptors.
Lytic enzyme induced by lysozyme mutant colitis phage and from a cloned gene.
Explore the source record for details and available documents.
In vitro synergy of ciprofloxacin and three other antibiotics against Bacteroides fragilis.
The potential in vitro synergistic effect of ciprofloxacin associated with mezlocillin, cefoxitin and clindamycin was evaluated against 30 strains of Bacteroides fragilis. All bacteria were clinical isolates, identified by gas chromatography and fermentation of carbohydrates. MICs of the drugs were determined by a miniaturized dilution broth method. Resistance or susceptibility to the drugs was not a criterion for the selection of the strains. Antibacterial combinations were tested by a checkerboard method utilizing brain hearth infusion broth and a bacterial inoculum of 10(6) CFU/ml. Microtitre plates were incubated at 37 degrees C for 48 h in anaerobic jars (BBL). Prereduced chopped meat carbohydrate broth was used to store and culture the strains. The effect of antimicrobial combinations was defined on the basis of the fractionary inhibitory concentration (FIC) indexes. We considered: synergistic effect FIC less than or equal to 0.5; additive effect FIC = 0.5-0.75; indifferent effect FIC = 0.76-2.0; antagonism FIC greater than or equal to 2. Ciprofloxacin + clindamycin showed synergistic activity against 10 strains out of 26 (38%); ciprofloxacin + mezlocillin against 9 strains out of 30 (30%); and ciprofloxacin + cefoxitin against 8 out of 29 strains (28%). Each antibiotic combination showed an additive or indifferent effect against all remaining bacteria. The synergistic effect of ciprofloxacin represents an important advantage in allowing the reduction of the dosage of associated drugs such as aminoglycosides or beta-lactams that can potentially be responsible for damage or side-effects.
Chronic granulocytic leukaemia in a haemophiliac.
Explore the source record for details and available documents.
Priapism in chronic myeloid leukaemia: combined medical & surgical treatment. A report on two patients.
Explore the source record for details and available documents.
Evaluation of carcinoembryonic antigen test in human mammary carcinoma.
Explore the source record for details and available documents.
Adenocarcinoma of ciliary epithelium in a young boy.
A rare case of adenocarcinoma of the ciliary epithelium is reported in a 17-year-old boy who had been mistakenly operated on for secondary glaucoma. There was extraocular extension and presentation as a fungating mass.
Prolonged defibrination syndrome after Echis carinatus bite.
Explore the source record for details and available documents.
Dynamic lung volumes in children with bronchial asthma.
Explore the source record for details and available documents.
Inbred strains of mice with variable sensitivity to ethanol exhibit differences in the content and processing of beta-endorphin.
The content of beta-endorphin-like immunoreactivity (beta-EPLIR) in the anterior and neurointermediate lobe of the pituitary gland, the hypothalamus and the serum of the c57BL/6, BALB/C and DBA/2 inbred strains of mice was estimated at the resting state as well as 45 min after i.p. injection of either ethanol solution (3.0 g/kg.b.wt.) or saline. At the resting state, the neurointermediate lobe and the serum of the c57BL/6 mice showed the highest content of beta-EPLIR, while no statistically significant difference was noticed in the total beta-EPLIR content in the anterior lobe and hypothalamus. At 45 min post-ethanol treatment the beta-EPLIR content was increased in the serum of all three strains of mice studied and was decreased in the hypothalamus of the c57BL/6 mice only. Further analysis of the beta-endorphin peptides using sephadex G-75 chromatography and reverse phase high performance liquid chromatography indicated strain differences in the relative proportions of the various forms of beta-endorphin in the anterior lobe, neurointermediate lobe and the hypothalamus. These strain specific differences in the content and post-translational processing of beta-endorphin may be involved in some of the genetically determined differences in responses to ethanol by these inbred strains of mice.
Transplacental transmission of hepatitis B virus.
Explore the source record for details and available documents.
Modulation of regulatory oxysterol formation and low density lipoprotein suppression of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase activity by ketoconazole. A role for cytochrome P-450 in the regulation of HMG-CoA reductase in rat intestinal epithelial cells.
The effects of ketoconazole, a lanosterol demethylase and cytochrome P450 inhibitor, on the regulation of 3-hydroxy-3-methylglutaryl coenzyme A reductase (EC 1.1.1.34, reductase) activity and sterol biosynthesis were studied in rat intestinal epithelial cell cultures (IEC-6). Incubation of cells with 0.15-2 microM ketoconazole resulted in a concentration-dependent inhibition of reductase activity. As the drug concentration approached 15 microM, the reductase activity returned to control values, and at 30 microM ketoconazole, a stimulation of enzyme activity was observed. The drug had no effect on reductase activity in homogenates of IEC-6 cells. Ketoconazole (0.15-30 microM) caused a concentration-dependent inhibition of the incorporation of [3H] mevalonolactone into cholesterol with a concomitant accumulation of radioactivity in methyl sterols; e.g. lanosterol and 24,25-epoxylanosterol. Interestingly, the incorporation of radioactivity into polar sterols showed a biphasic response which was inversely proportional to the biphasic response of reductase activity. Thus, incorporation of [3H]mevalonolactone into polar sterols increased at low concentrations of ketoconazole (0.15-2 microM) and decreased to control values at high concentrations of the drug. Treatment of cells with ketoconazole (30 microM) and [3H]mevalonolactone followed by removal of the drug and radiolabel resulted in an inhibition of reductase activity and a redistribution of radioactivity from lanosterol and 24,25-epoxylanosterol to cholesterol and polar sterols. These results suggested that the inhibition of reductase activity at low concentrations of ketoconazole (less than 2 microM) was due to a formation of regulatory polar sterols generated from the methyl sterols. At high concentrations of ketoconazole (30 microM) where no suppression in reductase activity was observed, the conversion of exogenously added [3H]24(S),25-epoxylanosterol to polar sterols was prevented. Exogenously added 24,25-epoxylanosterol inhibited reductase activity in a dose-dependent fashion, and ketoconazole (30 microM) prevented the inhibition caused by low concentrations of epoxylanosterol. The drug, however, was unable to prevent the dose-dependent suppression of reductase activity by 25-hydroxylanosterol, a reduced form of 24,25-epoxylanosterol. These results indicated that 24,25-epoxylanosterol per se was not an inhibitor of reductase activity but could be metabolized to regulatory polar sterols through a cytochrome P-450 dependent reaction which was sensitive to ketoconazole. Treatment of cells with ketoconazole totally abolished the inhibition of reductase activity by low density lipoprotein (LDL).(ABSTRACT TRUNCATED AT 400 WORDS)
Site specificity of histone H4 methylation by wheat germ protein-arginine N-methyltransferase.
CNBr treatment of calf thymus [methyl-14C]histone H4, methylated in vitro with S-adenosyl-L-[methyl-14C]methionine by a highly histone-specific wheat germ protein methylase I (S-adenosyl-L-methionine:protein-L-arginine N-methyltransferase, EC 2.1.1.23), produced two peptide fragments corresponding to residues 1-83 and 84-102, with the former being radioactive. Two-dimensional peptide mapping of the chymotryptic and tryptic digest of [methyl-14C]histone H4 and analysis of the chymotryptic digest on HPLC have shown that only a single peptide is radiolabeled. In order to define the exact site of methylation (arginine residue), the radioactive peptide from the chymotryptic digest of [methyl-14C]histone H4 was further purified on HPLC by linear and then isocratic elution. The purified chymotryptic peptide was then digested with trypsin and purified on HPLC, and its amino acid composition was determined on HPLC. These results indicate that the peptide corresponding to residues 24-35 of histone H4 is radiolabeled. Since this peptide contains a single arginine residue at position 35, we have concluded that the enzyme is specific not only to the protein substrate but also to the methylation site.
Restoration of suppressor T-cell functions in children with AIDS following intravenous gamma globulin treatment.
Suppressor T-cell function was analyzed in seven children with acquired autoimmunodeficiency syndrome (AIDS) or AIDS-related complex (ARC). Four of the patients had markedly increased serum IgG levels. All patients had elevated percentages and absolute numbers of peripheral blood T8 cells. In vitro concanavalin A generation of suppressor cells for T-cell mitogenic responses and suppression of pokeweed mitogen-driven immunoglobulin secretion were diminished in all patients. After intravenous treatment with gamma globulin, four patients regained in vitro suppression of pokeweed mitogen-driven gamma globulin secretion. Treatment with intravenous gamma globulin also modified in vitro suppressor T-cell functions in children with AIDS or ARC.
Activation of intrinsic coagulation pathway in pre-eclampsia.
Disseminated intravascular coagulation, thrombocytopenia, consumption of factors VIII and II, and antithrombin deficiency have been previously demonstrated in pre-eclampsia. However, the precise mechanism responsible for initiation of disseminated intravascular coagulation has not been elucidated. The present study documents activation of the intrinsic coagulation pathway in a patient with severe pre-eclampsia. The studies revealed marked reductions of plasma coagulant activities of all intrinsic pathway factors, i.e., XII, XI, IX, and VIII. In addition, the ratio of plasma factor XII activity to antigen concentration was markedly abnormal, and plasma high-molecular-weight kininogen concentration was diminished. It is suggested that activation of the intrinsic coagulation pathway may be operative in the genesis of disseminated intravascular coagulation in pre-eclampsia.