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Biomedical subjects

U Roy

Publications and source records attributed to U Roy.

9 recordsLinked to original sources
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↗
PubMed1979

Biofunctional evaluation of a hydrogen bond linking the ring and tail beta-turns of oxytocin.

Deamino-[8-N-methylleucine]oxytocin and deamino-[8-alpha-hydroxyisocaproic acid]oxytocin were synthesized to study the importance of hydrogen bonding between the carboxamide carbonyl of asparagine and the peptide N-H of leucine in stabilizing the biologically active conformation of oxytocin. The analogs were synthesized by coupling deaminotocinoic acid with Pro-Leu(Me)-Gly-NH2 and Pro-HyIc-Gly-NH2, respectively. (HyIc is alpha-hydroxyisocaproic acid). Deamino-[8-N-methylleucine]oxytocin was found to possess 48 +/- 7 units of uterotonic activity, 33 +/- 5 units of avian vasodepressor activity, and 3.15 +/- 1.5 units of antidiuretic activity per mg; deamino-[8-alpha-hydroxyisocaproic acid]oxytocin possessed 134 +/- 12 units of uterotonic activity, 31 +/- 3 units of avian vasodepressor activity, 9.6 +/- 3.0 units of antidiuretic activity, and 0.26 +/- 0.02 unit of pressor activity per mg. Neither of the analogs possesses the peptide N-H at residue 8 required for the formation of a hydrogen bond with the asparagine carboxamide; however, both can assume the conformation needed to evoke the characteristic biological activities of oxytocin although in lower potency. It is concluded that such a hydrogen bond does not constitute a conformational constraint that is essential for hormone action.

Animals↗