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Biomedical subjects

R Singh

Publications and source records attributed to R Singh.

At least 721 records · Page 40Linked to original sources
PubMed1981

Malignant epithelial tumors of the anal canal.

A simplified staging for malignant epithelial tumors of the anal canal is presented. The pattern of recurrence in males is pelvic and perineum, in females pelvis and posterior vaginal wall. Concomitant posterior vaginectomy is advocated. The disease is more common in females than males (4:1). There is little difference between histologic types, i.e. cloacagenic or squamous cell type. Recurrence and survival depend upon depth of invasion and extent of spread rather than histologic cell type. The tumors respond to well-designed surgery, radiotherapy and probably chemotherapy.

Adenocarcinoma↗
PubMed1981

Standardization of assay procedure and some properties of ribonuclease from Aspergillus candidus.

Screening of several fungal cultures resulted in the selection of an isolate of Aspergillus candidus which produced a considerable around of RNa-degrading enzyme in both surface and submerged methods of cultivation. The conditions for the assay of the RNAase were standardized at pH 4.5, 55 degrees C and using 0.25% yeast RNA as substrate. The enzyme was stable at pH 5.2. EDTA was found to activate the enzyme slightly. at temperatures 50-60 degrees C there was considerable loss in enzyme activity which was traced to the presence of a contaminating protease which presumably degraded the RNAase optimally at this temperature. The protease could be preferentially inactivated at or above 75 degrees C. The crude enzyme, in addition to RNAase was found to possess DNAase, nonspecific phosphodiesterase and 3'- and 5'-phosphomonoesterase activities.

Aspergillus↗
PubMed1981

Cyclophosphamide as a potential chemosterilant for harmful snails.

Cyclophosphamide induced changes in the ovotestis of the snail Lymnaea acuminata, the vector of the giant liverflukes Fasciola hepatica and Fasciola gigantica were studied in order to explore potential of the drug as a chemosterilant for snails. The drug caused a dose dependent reduction in the levels of DNA, RNA and proteins and the activity of the enzyme alkaline phosphatase. It increased the activity of acid phosphatase and the levels of total free amino acids in the ovotestis. While the animals showed nearly total recovery in RNA and DNA levels 7 days after termination of drug treatment, changes produced in protein, amino acid levels and phosphatase activity did not show any recovery. It appears that cyclophosphamide, while affecting its primary targets i.e. DNA and RNA, irreversibly inhibits protein synthesis through other cellular enzymes as well.

Acid Phosphatase↗
PubMed1981

Cerebral atrophy and functional deficits in alcoholics without clinically apparent liver disease.

Ninety-seven chronic alcoholics, both impaired and unimpaired, without clinically evident liver disease, showed significantly more cerebral atrophy on computed tomography than age-matched neurologic controls. Age was the variable most highly correlated with cerebral atrophy measurements, and it accounted for most of the correlations between atrophy and functional impairment, except in the Wernicke-amnesic group. Analysis of the slopes of atrophy scores versus age showed a more rapid "rate" of development of cerebral atrophy in alcoholics compared with controls. There were no correlations between liver biopsy scores (51 cases), drinking history (47 cases), or dietary intake (39 cases) and cerebral atrophy measurements.

Adult↗
PubMed1981

Cadaver nerve allografts in dogs.

Cadaver nerve allografts were studied in major histocompatibility complex-identical beagle donor/recipient combinations. Grafts were removed 3 and 6 hours after the death of the donor, preserved at -70 degrees C and transplanted as 7 cm long grafts at a later date. Graft function and histology was evaluated 9 to 11 months after transplantation by electromyographic examination and histological studies, respectively. Cadaver nerve allografts removed 3 and 6 hours after death show exactly the same excellent regeneration as the freshly removed cryopreserved nerve allografts in major histocompatibility complex identical combinations. This information is of value for future attempts to establish nerve banks of a many as possible different major histocompatibility types. Such banks will be required to accommodate the necessary donor/recipient matching for clinical nerve allografting.

Animals↗
PubMed1980

Use of girth measurements for estimating body volume and body density in Indian girls aged 10-19 years.

Mean values and standard deviations of total body volume, body density, height, weight, and a battery of 20 girth measurements of 200 Punjabi girls aged 10-19 years are presented. Selective stepwise multiple regression equations for predicting total body volume and body density from girth measurements are also given for different age groups. Hip girth was the most commonly selected measurement at the first step in most age groups and the values of 'r' between hip girth and total body volume ranged between 0.86-0.96 in different age groups. The values of multiple 'R' between total body volume and a combination of first four selected girth measurements varied from 0.96-0.99 in different age groups. The values of multiple 'R' between body density and a combination of four girth measurements selected up to fourth step ranged between 0.73-0.92 in different age groups.

Adolescent↗
PubMed1980

Prolonged cerebrospinal fluid acidosis in recently abstinent chronic alcoholics.

Significant cerebrospinal fluid (CSF) acidosis was evident in 80 chronic alcoholics (mean pH, 7.25 +/- 0.06) who were compared with 14 neurologic controls (mean pH, 7.31 +/- 0.02). Acidosis persisted for many weeks after the last drink, and there was no associated systemic acidosis. CSF pH correlated significantly with CSF anion gap, suggesting a primary cerebral metabolic abnormality. Even though one-quarter of the alcoholic patients had a CSF pH less than 7.21, mental impairment was less than expected for the degree of CSF acidosis noted.

Acidosis↗
PubMed1980

Ammonia anabolizing enzymes in cattle and buffalo fed varied nonprotein nitrogen and carbohydrates.

Adult male fistulated crossbred cattle and buffalo, four each, were on rations with rations of nonprotein nitrogen to carbohydrates of 1:45, 1:37.5, and 1:30 and a control of no urea in a 4 x 4 Latin square switchover design. The influence of various test diets on enzymes assimilating ruminal ammonia was elucidated to find an optimum ratio of nonprotein nitrogen to soluble carbohydrates for efficient utilization of dietary nitrogen. Inclusion of urea in graded amounts in the ration induced activities of amino-stransferases. Specific activities of trans-aminases were higher in cattle and buffalo for rations with ratios of 1:45 and 1:30 compared to control and 1:37.5 (nonprotein nitrogen to carbohydrate ratio). This indicates a better adaptation of rumen microbes on two former rations which did not differ in augmentation of enzyme activities. Peak enzyme activity of cattle and buffalo at 2 h postfeeding did not differ for microbial enzymes. The ration with narrowest nonprotein nitrogen and carbohydrate ratio (1:30) may be optimum for microbial synthesis of amino acid. It will be worthwhile to study whether a still narrower ratio can make feeding of ruminants more economical.

Amino Acids↗
PubMed1980

The suppressive effect of M. leprae on the in vitro proliferative responses of lymphocytes from patients with leprosy.

Peripheral blood lymphocytes from sixty leprosy patients and eight healthy contacts known to be responsive to M. leprae, were stimulated in vitro with concanavalin A (Con A) or PPD alone or in combination with autoclaved, whole M. leprae. Time kinetics and the percentage of inhibition induced by M. leprae differed in the two disease groups and contacts. Antigen-generated suppression of Con A-stimulated lymphocyte transformation was observed on day 4 in seventeen of twenty-one (80%) tuberculoid patients and six of seventeen (35.3%) untreated lepromatous patients. Healthy contacts and 53% lepromatous individuals showed enhanced Con A responses in the presence of antigen. On prolongation of antigen presence to 6 days, a marginal effect was noted in the tuberculoid group. In contrast, all healthy individuals and some lepromatous patients showed increased inhibition of Con A responses. M. leprae antigens showed uniform inhibition of PPD-induced 3H-thymidine incorporation in leprosy patients and healthy contacts.

Antigens, Bacterial↗