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Biomedical subjects

D Dutta

Publications and source records attributed to D Dutta.

At least 127 records · Page 7Linked to original sources
PubMed1983

Induction of benzo(a)pyrene hydroxylase in Aspergillus ochraceus TS: evidences of multiple forms of cytochrome P-450.

The filamentous fungus Aspergillus ochraceus TS produces an inducible microsomal cytochrome P-450 linked monooxygenase which is capable of hydroxylating benzo(a)pyrene in presence of O2 and NADPH. The addition of Benzo(a)pyrene, 3-Methyl cholanthrene, beta-Naphthoflavone and other aryl hydrocarbons during the induction period causes dramatic improvement in the kinetics of benzo(a) pyrene hydroxylation as was evidenced by large decrease in Km and increase in Vmax values. On the other hand, treatment with Phenobarbital, Polychlorinated biphenyl and Progesterone has no significant effect on the kinetics of benzo(a)pyrene hydroxylation although a significant induction of NADPH-Cyt C reductase activity was observed in all the three cases. Again, both Phenobarbital and 3-Methyl cholanthrene induced microsomes exhibit the characteristic reduced metyrapone difference spectra. These findings together with the results obtained with flavone on the metabolism of benzo(a)pyrene by various microsomal preparations suggest a parallel induction of multiple forms of cytochrome P-450 as observed in mammalian liver under identical condition.

Aryl Hydrocarbon Hydroxylases↗
PubMed1983

Microsomal benzo(a)pyrene hydroxylase in Aspergillus ochraceus TS: assay and characterization of the enzyme system.

Microsomal preparations of Aspergillus ochraceus TS oxidised benzo(a)pyrene very efficiently in the presence of NADPH and 02 and exhibits a pH optimum of 8.0-8.2. The hydroxylation is also effected in presence of NaI04. Hydroxylation was inhibited by metyrapone, SKF-525A, PCMB, imidazole, carbon monoxide and flavone but not by cyanide, azide and antimycin A indicating thereby the involvement of cytochrome P-450 in this reaction. Inhibition by cytochrome C is consistent with the participation of NADPH-cytochrome C reductase in this hydroxylation. Reduced microsomes and its solubilized preparation, when treated with carbon monoxide, showed absorption maxima at 453 and 449 respectively. Different classical inducers of cytochrome P-450 induce the benzo(a)-pyrene hydroxylase activity to varying degree and as such suggests the existence of multiple forms of cytochrome P-450 in this fungus.

Aryl Hydrocarbon Hydroxylases↗
PubMed1981

Antibacterial and antitoxin responses in the serum and milk of cholera patients.

Antibacterial and antitoxin responses in the acute and convalescent (7 to 10 days) sera of 14 cholera patients were determined by various serological techniques. Similar studies were also carried out with corresponding milk samples of six of these patients who were lactating women. A significant rise in antibacterial titers was observed in all convalescent serum and milk samples. A similar rise in antitoxin titers was observable in all serum and four milk samples. Specificity of the antibacterial titers was further evaluated by the indirect hemagglutination test using lipopolysaccharide antigen, and close correlations were noted between these titers and vibrio agglutination (P<0.001) and vibriocidal (P<0.001) titers of sera. Serum and milk convalescent cholera patients could effectively neutralize cholera toxin action in vivo, although the neutralizing activity of serum was higher than that of milk. Determination of antibody titers by the enzyme-linked immunosorbent assay demonstrated that anti-lipopolysaccharide activity in sera belonged predominantly to immunoglobulin M (IgM) and, to a lesser extent, to IgG and IgA, whereas such activity in milk was mostly contributed by secretory IgA, although some IgM antibodies also could be detected. On the other hand, antitoxic activity in convalescent sera primarily belonged to IgG, whereas such activity in milk was almost exclusively contributed by secretory IgA. These results demonstrate that an antibody response in the mammary gland was stimulated due to the antigen exposure in the gut and are consistent with the idea of a common homing pattern of immunocytes within the secretory immune system. Moreover, some differences in the antibody production mechanism between the systemic and secretory immune systems are indicated.

Antibodies, Bacterial↗
PubMed1979

Pathways of urinary backflow in obstructive uropathy. Demonstration by pigmented gelatin injection and Tamm-Horsfall uromucoprotein markers.

The exact pathways of urinary reflux into the renal veins were studied in four cases of clinical obstructive uropathy and in 50 normal human cadaver kidneys. In the four clinical cases Tamm-Horsfall uromucoprotein was used as a marker for location of urine. Routine light microscopy and indirect immunofluorescence for Tamm-Horsfall uromucoprotein using rabbit antiserum showed tubular backflow up to the glomerulus. Dilated tubules filled with Tamm-Horsfall uromucoprotein ruptured into thin walled veins, forming tubulovenous anastomoses with extrusion of their contents into veins. The uromucoprotein was present in interlobar and arcuate veins with superimposed thrombosis and thrombophlebitis. Injection studies using pigmented gelatin in 45 normal cadaver kidneys and pigmented vinylite with corrosion casts in five additional kidneys complemented the clinical studies. Two types of urovascular communication were produced: the less frequent direct pyelovenous communication between a rupturing fornix and an adjacent small vein, and the more common indirect pyelovenous communication in which a ruptured fornix produced a sinus extravasate, which extended along the perivenous spaces of interlobar and arcuate veins. This extravasate gained access into the veins at points of rupture where venous tributaries joined the major veins in the renal medulla. The clinical implications of these tubulovenous and pyelovenous pathways of urinary reflux include backflow of whole urine and continued nephronic function in obstructive uropathy, "reverse backflow" of blood and hematuria, and a direct access for infectious agents into the circulation. These channels provide anatomic correlates for radiologic findings of extravasates and some backflow patterns of contrast material in pyelograms of clinical obstructive uropathy. The possible immunologic consequences of refluxing Tamm-Horsfall uromucoprotein gaining access to tissues and circulation are speculative.

Adult↗
PubMed1976

Doxycycline in the treatment of cholera.

Doxycycline was compared with tetracycline in the treatment of cholera. Four types of treatment were compared: Group A was given 200 mg of doxycycline on admission and 100 mg on the second day; Group B was given 200 mg of doxycycline on admission only; Group C was given 300 mg of doxycycline on admission only; and Group D received 500 mg of tetracycline every 6 h for 48 h. Tetracycline showed a slight advantage in respect of duration of diarrhoea and vibrio excretion compared with doxycycline given as a single dose of 300 mg, but fluid intake and output were about the same in these two groups. The other two doxycycline treatment schedules did not compare well with tetracycline treatment.

Adolescent↗
PubMed1975

Hyposplenic, coagulopathic, cryptogenetic pneumococcemia.

An unusual case of sudden, fulminant pneumococcemia and disseminated intravascular coagulation occurred in a woman who had had incidental splenectomy 8 months previously, at the time of gastrectomy for duodenal ulcer. Similar cases in which there is constant relationship of splenectomy, pneumococcal sepsis, and Waterhouse-Friderichsen syndrome have been documented. Other similarities which are notable are a tendency for the disease to occur in women, lack of a nidus of infection, and proliferation of diplococci to numbers great enough to be seen easily on the peripheral blood smear.

Adrenal Gland Diseases↗
PubMedDate not supplied

Efficacy of lumiracoxib in osteoarthritis: a review of nine studies.

Lumiracoxib is a cyclooxygenase-2 selective inhibitor in development for the treatment of osteoarthritis (OA), rheumatoid arthritis and acute pain. We reviewed nine clinical studies of 1-52 weeks' duration demonstrating the efficacy of lumiracoxib in OA. Male and female patients aged > or = 18 years with primary OA of the hand, hip or knee received lumiracoxib, placebo or active comparators (diclofenac, celecoxib or rofecoxib). Lumiracoxib provided consistent reductions in OA pain intensity and improvements in the patient's global assessment of disease activity and functional status (assessed using the Western Ontario and McMaster Universities Osteoarthritis Index questionnaire or the Australian/Canadian OA Hand Index). These results were superior to placebo and similar to the active comparators tested. In addition, lumiracoxib was consistently superior to placebo and generally similar to active comparators in terms of the new Outcome Measures in Clinical Trials and Osteoarthritis Research Society International criteria. These were used to provide a single measure of response to treatment, taking into account pain, the patient's global assessment of disease activity and functional status.

Diclofenac↗