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Biomedical subjects

R N Kulkarni

Publications and source records attributed to R N Kulkarni.

49 records · Page 3Linked to original sources
PubMed1989

The influence of different methods on basal metabolic rate measurements in human subjects.

While collating basal metabolic rate (BMR) measurements made worldwide it becomes important to know how different instruments compare with each other and whether errors in methodology could account for the differences in BMRs measured. BMRs of 34 healthy individuals were measured by using five different instruments in various combinations. Results show that energy outputs were comparable between the oxylog. Hartmann and Braun Metabolator, ventilated tent and hood, and whole-body indirect calorimeter: small differences, if any, were not statistically significant. However, significant interactions existed between subjects with the ventilated tent and hood and calorimeter when measurements were taken in subjects who were unaccustomed to the apparatus. When converting O2-consumption measurements to energy output, some instruments make assumptions that introduce a variable error in the final result, which may lead to systematic errors during the compilation of large databases of human BMRs.

Adult↗
PubMed1989

Reduced thermoregulatory thermogenesis in undernutrition.

Adaptive responses to chronic energy deficiency could occur in one of the important components of energy expenditure ie, regulatory thermogenesis. We assessed the thermogenic responses to standardized noradrenaline (NA) infusions in undernourished labourers, as well as in normally nourished control subjects. There was a significant suppression (greater than 60 per cent) of NA-stimulated oxygen consumption in the undernourished, which remained statistically significant even when the responses were corrected for fat-free mass differences. This first report of a suppression in regulatory thermogenesis indicates its important role in the adaptive response to lower than required energy intakes in human subjects.

Adult↗
PubMed1988

Prediction of steady-state oxygen consumption during norepinephrine infusions in humans.

A method for predicting maximal oxygen consumption during norepinephrine infusion is described. Using the initial response and enzyme kinetics, predicted values of maximal oxygen consumption were compared with observed values and a coefficient of variation of 1.4% was obtained. This method is of use in situations where it may not be possible to achieve steady-state conditions, especially with high doses of norepinephrine, and it permits comparison of maximal oxygen consumption between groups.

Adult↗
PubMed1984

Radiation dose to the breast during mammography: a comprehensive, realistic Monte Carlo calculation.

Certain assumptions have been made regarding the composition of the breast in different age groups: these are believed to be more realistic than existing assumptions and have been used in comprehensive Monte Carlo calculations of radiation dose to the breast and of appropriate indicators of risk as follows: (i) Mean dose to the sensitive tissues in an average breast. This may be used to compare risk in different mammographic techniques, and has been calculated for a wide variety of techniques, including some not previously explicitly studied. (ii) Integral dose to the sensitive tissues in a breast, which is a good indicator of risk in an individual case, has been calculated for two commonly used mammographic techniques and for four different breast compositions and thicknesses. The results have been compared with results obtained using other approaches.

Adolescent↗
PubMed1981

Monte Carlo calculation of the dose distributions across a plane bone-marrow interface during diagnostic X-ray examinations.

The distribution of dose across a plane bone-marrow interface on irradiation with various diagnostic X-ray beams at a representative site have been determined using the Monte Carlo method. The site was in a dorsal vertebra near its surface and situated at a depth of 70 mm under the skin. The X-ray beams studied were generated at 100, 90, 80 and 70 kV with 2 mm aluminium added filter and at 55 kV with 1 mm aluminium added filter. It was found that the dose to bone marrow due to excess photoelectrons produced in bone falls off rapidly as the distance from the bone-marrow interface increases. Consequently, the percentage excess dose to a plane bone-marrow cavity, which is almost constant for the range of kV studied, is significant only if the cavity size is small.

Bone Marrow↗
PubMed1980

Contribution of electron contamination to the skin dose in teletherapy with Co-60 gamma-rays.

The contribution of electron contamination to the dose received by the skin and the underlying tissues during teletherapy with 60Co gamma-rays has been determined by an indirect method. First, the distribution of dose under the skin due to an uncontaminated beam of 60Co gamma-rays was determined using the Monte Carlo method without any major assumption. This distribution was then subtracted from the measured distribution of total dose available in the literature, to get the required dose distribution due to electron contamination. The distribution as determined in this work has been compared with that determined by some other workers, who relied on the dose distribution due to an uncontaminated beam calculated under some assumptions. It was found that the dose due to electron contamination was overestimated by them in the middle depths. This was as expected, because with their assumptions in the calculation of the dose distribution due to an uncontaminated beam, this dose is underestimated in the middle depths.

Cobalt Radioisotopes↗
PubMedDate not supplied

Symmetry C18 column: a better choice for the analysis of indole alkaloids of Catharanthus roseus.

By virtue of the different elution patterns of vindoline, catharanthine, vincristine and vinblastine present in the leaves of Catharanthus roseus plants, a Symmetry C18 column provided a better resolution for all of these compounds as compared with other C18 columns. The binary gradient system with a linear gradient profile, employed in a method developed using a Symmetry C18 column, gave excellent peak symmetry, resolution and reproducibility. Detection was performed at 220 nm which presented better absorptivity for these indole alkaloids giving a minimum detection limit of 0.5 microgram. Photodiode array detection was used to determine the homogeneity and purity of each compound. The described analysis is rapid and economical to perform as small amounts of solvent are consumed per analysis, and the method will find application where a large number of samples are to be analysed as, for example, in crop improvement studies where plants need to be selected regularly on the basis of alkaloid production.

Apocynaceae↗
PubMedDate not supplied

Net mechanical efficiency during stepping in chronically energy-deficient human subjects.

Mechanical efficiency during a step test was measured in chronically energy-deficient (CED) individuals and compared to well-nourished subjects using a whole-body indirect calorimeter. The CED group had significantly higher net mechanical efficiencies than the well nourished subjects. This was also evident in the 15% lower energy costs observed in the CED subjects when expressed as a percentage of the predicted data. Factors such as a higher proportion of slow muscle fibres as well as a greater ergonometric efficiency may contribute to the observed higher muscular efficiency aiding conservation of energy expenditure in these individuals.

Adolescent↗
PubMedDate not supplied

Inheritance of flower color in periwinkle: orange-red corolla and white eye.

The commonly found flower colors in periwinkle (Catharanthus roseus)--pink, white, red-eyed, and pale pink center--are reported to be governed by the epistatic interaction between four genes--A, R, W, and I. The mode of inheritance of an uncommon flower color, orange-red corolla and white eye, was studied by crossing an accession possessing this corolla color with a white flowered variety (Nirmal). The phenotype of the F(1) plants and segregation data of F(2) and backcross generations suggested the involvement of two more interacting and independently inherited genes, one (proposed symbol E) determining the presence or absence of red eye and another (proposed symbol O) determining orange-red corolla.

Anthocyanins↗
PubMedDate not supplied

A study of leucorrhoea in reproductive age group women of Nagpur City.

A community based cross-sectional study was conducted in reproductive age group women in an urban community of Nagpur, to assess the prevalence of leucorrhoea and the factors influencing the same in these women. The study participants included 506 females, out of which 149 were unmarried and 357 were married. Detailed history and clinical examination was done in all the females including gynecological examination in all the married females. Leucorrhoea was present in 139 (27.47%) females. Leucorrhoea was found significantly more in married females as compared to unmarried (p < 0.001), pregnant as compared to non-pregnant (OR = 2.10, 95% C.I. = 1.02-4.32), and women of lower socioeconomic status (p < 0.001), women with high parity (p < 0.001). Use of Cu-T was not associated with Leucorrhoea (p > 0.05).

Cross-Sectional Studies↗