Search PubMed⌕ Search

Biomedical subjects

U Roy

Publications and source records attributed to U Roy.

At least 19 recordsLinked to original sources
PubMed2003

The incidence and immediate respiratory consequences of pulmonary aspiration of enteral feed as detected using a modified glucose oxidase test.

Pulmonary micro-aspiration of enteral feed in intubated critically ill patients has been reported to occur commonly. In this prospective observational study the incidence of micro-aspiration, diagnosed by a modified glucose oxidase test, is reported in 25 enterally fed critically ill and tracheally intubated patients on a general intensive care unit. Episodes of microaspiration were correlated with changes in PaO2/FiO2 ratio as an index of changes in degree of lung injury. The modified glucose oxidase test differs from the traditional glucose oxidase test because of the enrichment of the feed with glucose (10 g glucose added to 500 ml enteral feed resulting in a tenfold increase in glucose concentration). Pulmonary aspiration of feed was detected by exposing a glucose oxidase strip to tracheal secretions. The feed was enriched with glucose to improve the ability of the reagent strip to detect the feed. The incidence of aspiration of feed was 44% with a prevalence of 6.9% per day of intubation. Only 43% of these episodes of aspiration were detected by the feed being seen in the tracheal secretions. Aspiration was associated with a mean fall in the PaO2/FiO2 ratio of 5.6 kPa from 27.1 kPa to 21.5 kPa (P = 0.002). Aspiration of enteral feed is common and causes a demonstrable morbidity. Detection using this simple bedside test may alert the clinician to institute measures to minimize further aspiration.

Enteral Nutrition↗
PubMed2002

Effect of different strains of yeast on stereocontrolled reduction of 5-acetylisoxazolines.

The stereocontrolled reduction of 3-aryl-5-acetylisoxazolines (1) to the corresponding alcohols (2 and 3) in the presence of four different yeast strains, recognized as Baker's yeast (commercial), Candida krusei (ATCC 14243), Pichia farinosa (NRRL Y110) and Sacchromyces sp. (soil isolate) have been attempted. The C. krusei was found to be diastereoselective for the (R)-1 while the Sacchromyces sp. led to complete reduction to yield the RS- and SS-alcohol in 1:1 ratio at 10 g/L scale.

Biotransformation↗
PubMed1998

Protective effect of Picroliv from Picrorhiza kurroa against Leishmania donovani infections in Mesocricetus auratus.

The prevalent drugs for treatment of kala azar viz. sodium stibogluconate (SSG) and pentamidine cause severe toxic side effects and acute immunosuppression in the treated individuals. Picroliv, a standardized mixture of iridoid glycosides, prepared from the alcoholic extract of the root and rhizome of Picrorhiza kurroa has shown strong hepatoprotective activity against several models of hepatotoxicity. Therefore, the present study was undertaken with an objective to study the effects of Picroliv (12.5 mg/kg x 7 days oral) alone and in combination with SSG on parasitemia, lipid peroxidation and hepatic marker enzymes of golden hamsters during Leishmania donovani infection. The results indicated a marked hepatoprotective effect of Picroliv in terms of biochemical markers, and a significant antileishmanial activity implying that it can be utilized as an adjunct to chemotherapy or in combination therapy of kala azar along with sodium stibogluconate, thus enhancing the efficacy of antileishmanials.

Administration, Oral↗
PubMed1997

Antifungal attributes of lactic acid bacteria--a review.

Molds constitute a very important contaminating flora of dairy products. Contamination with undesirable molds has been a serious and frequently disturbing problem in the dairy industry that results in huge losses due to spoilage of cheese and other fermented foods incriminated by a variety of mycoflora such as Aspergillus, Penicillium, Fusarium, Rhizopus, and Mucor. The considerable drop in pH caused by the growth of lactic acid bacteria (LAB) in fermented milk makes such foods a breeding ground for the highly opportunistic fungi to proliferate and thrive, spoiling the products and effecting cost and its commensurate accessories. The major antimicrobial substances isolated from the LAB are found effective against bacteria only and their inhibition toward the growth of contaminating bacteria has been explored in detail. However, studies on the fungistatic properties of LAB are relatively rare. This article reviews the investigative studies on the antifungal aspects of different lactic acid bacteria and the prospects of this exceptional trait as a potential food biopreservative.

Animals↗
PubMed1996

Production of antifungal substance by Lactococcus lactis subsp. lactis CHD-28.3.

Six of the 2100 colonies of lactic acid bacteria isolated from 4 month old Cheddar cheese and raw buffalo milk showed antifungal activity against Aspergillus flavus IARI when tested by the well agar diffusion assay on Potato Dextrose Agar containing 0.1% Triton X-100. Out of these, the most promising isolate having a broad spectrum of antifungal activity including Aspergillus flavus IARI, A. flavus NCIM 555, A. parasiticus NCIM 898 and Fusarium spp. was identified as Lactococcus lactis subsp. lactis CHD-28.3. Among the mold cultures used as indicator strains, the most sensitive towards antifungal substance produced by the test culture was A. flavus IARI. The cell-free supernatant of the test culture in Elliker's broth adjusted to pH 6.8 produced an inhibition zone of 15-19 mm against A. flavus IARI, A. flavus NCIM555 and A. parasiticus NCIM898. The isolate when grown at 30 degrees C for 48 h in Elliker's broth showed optimum antifungal activity. When the supernatant was neutralized to pH 7.0 or 7.5, there was little reduction in activity. However, after enzymatic treatment of supernatant with chymotrypsin, trypsin and pronase E, the antifungal activity disappeared which indicated the proteinaceous nature of the antifungal substance.

Antifungal Agents↗
PubMed1996

Relative resistance of promastigotes of a virulent and an avirulent strain of Leishmania donovani to hydrogen peroxide.

Sensitivity of promastigotes of Leishmania donovani (Dd-8, virulent: UR-6 avirulent strain) to hydrogen peroxide has been studied in vitro conditions. There was a dose-dependent toxic effect of H2O2 on both strains. The promastigotes of Dd-8 strain, however, were more resistant compared to UR-6 strain. The cell response was not affected by the forms of H2O2 stress, for instance, single-dose exposure with reagent H2O2 or equivalent amount generated over a period of 1 h. Dd-8 promastigotes removed H2O2 from medium at a higher rate (6.43 nmol/min/ 3 x 10(7) cell/ml) compared to UR-6 promastigotes (3.17 nmol/min/3 x 10(7) cells/ml). Hydrogen peroxide metabolism by Dd-8 cells was significantly inhibited by aminotriazole, azide, and thiol reagents, while that of UR-6 cells was sensitive only to thiol reagents. The results are consistent with the negligible activity of glutathione peroxidase and nondetectable catalase in UR-6 promastigotes; both enzyme activities were present in Dd-8 promastigotes. These findings suggest that the ability of the parasite to resist H2O2 toxicity may have a potential role in its virulence.

Animals↗
PubMed1990

[An occurrence of a neurogenic sarcoma in an irradiated field following the combined surgical-radiologic treatment of a childhood adenosarcoma of the kidney].

Malignant neoplasias in childhood generally are an increased risk for the patient to fall ill with a second tumor. Second tumors in former irradiation field are seldom, but are acknowledged radiogenically if histology is different to that of the first tumor and a sufficiently long period is between the two tumors. A patient is represented who had been operated and irradiated because of an adenosarcoma of the kidney at the age of seven and who has fallen ill with a neurogenic sarcoma in irradiation area more than 30 years later. The same patient had to suffer from radiogenic retardation during differentiation of lumbar apparatus of attitude and locomotion and on the other hand he became father of a healthy daughter at the age of 32.

Child↗
PubMed1990

[Radiogenic pneumopathy in irradiated breast cancer--a follow-up assessment based on chest radiographs].

In 232 surgically treated and irradiated patients with breast carcinoma 27 cases of radiogeneous pneumopathia were found and analyzed in the chest radiograph. Special attention was given to the evaluation of the stage and the course of the radiation pneumonitis. No correlation between clinical results and x-ray symptoms was seen. Not every roentgenologically diagnosed pneumonitis is seen in the late follow-up as a fibrosis. The reasons for this are discussed. For the improved detectability of pneumonitic changes in the p.a. or lateral image no significant differences were found and no general rules. Additional CT-investigations of the chest demonstrated the radiogeneous lung changes more clearly and more exactly in its depths. Therefore an exact use of CT in the diagnostics of pneumonitis can be useful, but must be seen under the aspects of relevant therapy the availability of methods and economy.

Adult↗
PubMed1989

Purification and properties of a carboxymethylcellulase from phytopathogenic fungus Macrophomina phaseolina.

From the culture filtrate of Macrophomina phaseolina, two forms of carboxymethylcellulase were separated by ion-exchange chromatography and designated as CMCase-I and CMCase-II. CMCase-I was purified following a four-step procedure involving gel filtration on Sephadex G-75, Con-A Sepharose 4B affinity chromatography, fast protein liquid chromatography on mono Q anion-exchanger and on Superose 12 gel filtration. The final preparation was homogeneous by SDS-PAGE, isoelectric focussing in thin layers of polyacrylamide gels and immunoelectrophoresis. The enzyme showed optimum activity at pH 5.5 and 65 degrees C, was stable to heating at 65 degrees C for 10 min, and retained 31% of original activity after heating at 80 degrees C for 10 min. The molecular weight of the enzyme was 3.5 x 10(4) Da. A Km of 0.25 mg/ml was determined using carboxymethyl-cellulose as the substrate.

Carboxymethylcellulose Sodium↗
PubMed1989

[Modern imaging procedures in the diagnosis of an acute apoplectic insult and their therapeutic consequences].

The acute occlusion of arteries as an acute condition demands immediate action. Previously the radiologist was only involved with the angiography elucidation but with the advent of hemolytic therapy a close cooperation of radiologist and intensive care physicians becomes necessary. Under intensive care conditions, the radiologist must be available around the clock, even at night and on holidays. First results of haemolytic therapy seem to justify these efforts.

Adult↗
PubMed1987

Selective targeting of boronophenylalanine to melanoma in BALB/c mice for neutron capture therapy.

Melanoma cells actively accumulate aromatic amino acids for use as precursors in the synthesis of the pigment melanin. Using the Harding-Passey melanoma carried s.c. in BALB/c mice, we have demonstrated that p-boronophenylalanine (BPA) is taken up by melanoma tissue to a much greater extent than by normal tissues. Following a single i.p. injection, or a series of injections given over 1 h, the accumulation of boron in melanoma was found to be transient, reaching a maximum approximately 6 h postinjection. The concentrations of boron achieved in tumor ranged from 9-33 micrograms/g, and are within the range estimated to be necessary for successful application of the nuclear reaction 10B(n,alpha)7Li for neutron capture therapy. Boron concentrations in tumor and tissues were determined using either a prompt-gamma spectroscopic technique or by quantitative neutron capture radiography using whole-body sections. Distribution studies with the resolved stereoisomers of BPA indicated that the L isomer is preferentially accumulated in the melanoma compared to the D isomer. The L isomer of BPA was shown to be targeted to actively dividing tumor cells by simultaneously comparing the boron and [3H]thymidine distribution in tumor. Under conditions which selectively deliver high concentrations of boron to Harding-Passey melanomas in BALB/c mice, BPA did not deliver useful concentrations of boron to a mammary adenocarcinoma in Hale-Stoner mice. These results, along with the selectivity of the Harding-Passey melanoma for the L isomer of BPA, are consistent with our working hypothesis that BPA is actively transported into the melanomas as an analogue of natural melanin precursors.

Animals↗
PubMed1986

Desaminopenicillamine tocinoic acid derivatives--inhibitors of oxytocin.

Tocinoic acid analogs with penicillamine in place of one or both of the cysteine residues have been studied and [1-beta-mercaptopropionic acid, 6-penicillamine] tocinoic acid (dPen6TA) and [1-beta,beta-dimethyl-beta-mercaptopropionic acid, 6-penicillamine] tocinoic acid (dPen1Pen6TA) have been synthesized in solution. Biological activities of these 2 compounds and those of the previously synthesized [1-beta,beta-dimethyl-beta-mercaptopropionic acid] tocinoic acid (dPen1TA) have been assayed. It was found that dPen1TA and dPen1Pen6TA, both of which have a beta,beta-dimethyl-beta-mercaptopropionic acid in position 1, are strong inhibitors of the uterine activity of oxytocin in vitro (without Mg2+) with pA2 values of 7.1 and 7.8, respectively, whereas dPen6TA with penicillamine in position 6 is a mild agonist.

Amino Acid Sequence↗
PubMed1983

Biofunctional evaluation of two hydrogen bonds stabilizing the beta-turn in the acyclic component of oxytocin.

The depsipeptide [8-alpha-hydroxyisocaproic acid, 9-glycolic amide]-oxytocin, which has ester linkages replacing the peptide linkages between the 7th and 8th and the 8th and 9th residues of oxytocin, has been synthesized by a (6 + 3) condensation of Boc-tocinoic acid with Pro-O-HyIc-O-Glyc-NH2, followed by deprotection of the resulting product. The analog exhibited the following activities in rats: 258 +/- 11 and 28 +/- 5 U/mg, uterus in vitro in the absence and presence, respectively, of Mg+2; 54 +/- 4 U/mg, uterus in vivo; 19.3 +/- 2.1 U/mg, milk ejection; 0.153 +/- 0.026 U/mg, antidiuretic activity; and no pressor activity. The need for the presence of the peptide linkages mentioned above as sources for internal hydrogen bonds to stabilize the "biologically significant" conformation is discussed.

Amino Acid Sequence↗
PubMed1983

[1-Desaminopenicillamine, 8-alpha-hydroxyisocaproic acid] oxytocin. A selective inhibitor in rats of the uterine response to oxytocin.

[1-Desaminopenicillamine, 8-alpha-hydroxyisocaproic acid] oxytocin was synthesized by a 6 + 3 fragment condensation from precursors which had been formed by solution methods. This analog inhibited uterine responses to oxytocin (pA2 7.37, 7.9, 6.17; uterus in vitro without Mg++, in vitro with Mg++, and in vivo, respectively) and showed little or no activity in other bioassays.

Amino Acid Sequence↗