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Biomedical subjects

R Roy

Publications and source records attributed to R Roy.

At least 325 records · Page 18Linked to original sources
PubMed1989

Sensitivity of bioelectrical impedance to detect changes in human body composition.

The purpose of this study was to compare the estimates of lean body mass (LBM) and percent body fat (%BF), as predicted by bioelectrical impedance (BIA) and sum of skinfolds (SF), with those derived by hydrostatic weighing (HW) obtained before and after a 10-wk diet and exercise regimen. The experimental (E) group consisted of 17 healthy male subjects; 20 healthy males served as the control (C) group. Post hoc Scheffé contrasts computed on E group data indicated that, for both LBM and %BF, the Lukaski and Segal BIA equations, as well as the Durnin SF equation, derived mean values that were not significantly different (0.05 significance level) from HW in both pre- and postregimen conditions. For LBM, the same equations derived the following significant (P less than 0.01) correlation coefficients for both pre- and postregimen data: Lukaski, 0.87 and 0.85; Segal, 0.89 and 0.87; and Durnin, 0.90 and 0.88. For %BF, the correlation coefficients were slightly lower but remained statistically significant (P less than 0.01). The findings of this study suggest that the BIA method, by use of either the Lukaski or Segal prediction equations, is a valid means of predicting changes in human body composition as measured by the Siri transformation of body density.

Adipose Tissue↗
PubMed1989

Memories of pain: comparison of "worst pain ever" experienced by senior citizens and college students.

A total of 124 senior citizens were compared with 99 college students for their memory of worst pain experience and the action they undertook to deal with that experience. Seniors recalled very recent pain experiences, as did the students. There were major differences in their description of the worst pain experience and also how they had their pain problems dealt with. Implications of these findings are discussed.

Adult↗
PubMed1989

[Rejection following corneal transplantation. Effect of HLA compatibility of the grafts].

One hundred and fifty-two consecutive corneal transplants were performed with recipients selected on the basis of the best HLA-A, B, and DR match, and observed for corneal transplant rejection episodes. Following a descriptive analysis of data, the transplants were subdivided into well matched transplants (109 cases) and poorly matched transplants (43 cases). The rejection rate of poorly matched transplants was 2.37 times higher than that of well matched transplants (p = 0.09). Analysis of survival curves, three years after transplantation, shows a 91% rejection-free survival of well matched transplants compared to 78% for poor matched transplants. These findings suggest that the risk of corneal transplant rejection may be reduced by optimal HLA-A, B, and DR matching.

Adult↗
PubMed1989

Conceptive delays of twin-prone mothers: a demographic epidemiologic approach.

We studied the time interval to the first birth and to the twin birth using statistical and mathematical models in two groups of mothers, those with twins and those with singletons, from the same population. We made use of a pair-matched case-control design. We treated the maternal birth cohort and parity as confounders and thus as controlled. We also investigated the sex of twin pairs as an interactive variable, employing such methods as survival curve testing and using geometric, gamma, and exponential distributions where appropriate. The expectations derived from the mathematical models yield numerical estimates of fertility components. The results suggest that unlike-sex twin-prone mothers have higher fecundity than controls when they conceive singletons. Further, fecundity appears high and unimpaired before the birth of twins. Mothers of like-sex twins experience somewhat shorter and but more variable birth intervals than corresponding controls before the birth of twins, suggesting within-group heterogeneity. Specifically, the birth of like-sex twins is preceded by low fecundity and a short period of postpartum amenorrhea. Biologically, like-sex (presumably monozygotic) twin-prone mothers have a hormonal defect related eventually to menopausal status that interferes with ovulation and perhaps with lactation. As for unlike-sex twin-bearing mothers, they probably experience a displacement of their maximum fertility potential toward early reproductive life and an extension of their menstrual life. From a methodologic standpoint, the study of the fertility of twin-prone mothers cannot proceed without estimates of the fertility components of birth intervals, as these intervals do not lend themselves to straightforward analytical interpretations by statistical analyses.

Adult↗
PubMed1988

Immunosuppressive effects of rabbit blastocoelic fluid and embryo culture medium.

In order to understand the mechanism of the feto-maternal immune relationship, we assayed the immunosuppression activities of fresh blastocoelic fluid and decomplemented peripheral serum collected from day-9 pregnant white New Zealand rabbits and of rabbit embryo culture medium (ECM). Because the viability of the human lymphocytes was not affected by either of these biological fluids and since they were easy to obtain in sufficient quantities, they were used uniformly in all the experiments. Immunosuppressive effect was calculated by the relative inhibition of proliferation of Con A-stimulated lymphocytes. The immunosuppressive effect of blastocoelic fluid of the 9-day pregnant rabbits was significantly higher than that of autologous decomplemented serum (P less than 0.001). The inhibition by the serum was non-specific because sera from non-pregnant animals as well as sera from different stages of pregnancy and pseudo-pregnancy showed the same level of inhibition. The ECM of 6.5-7-day-old embryo showed a pronounced immunosuppressive effect. When embryos of 1,3 and 5 days were cultured and their culture media were assayed only with 5-day-old embryo the effect had begun to appear, but it was far less than that of 7-day-old embryo (P less than 0.02). The suppressive activity of both the blastocoelic fluid and ECM was not due to cytotoxic effect, since this fluid supported the in vitro growth of single-cell rabbit embryos up to the stage of blastocyst. These results suggest that the immunologic tolerance of the embryo might be due to the immunosuppressors secreted by the embryo and that there might be a localized effect at the implantation site rather than a maternal systemic immunosuppressive effect.

Animals↗
PubMed1988

Enoxacin penetration into human prostatic tissue.

Concurrent enoxacin concentrations in serum and prostatic tissue were determined in 14 patients. The mean ratios of enoxacin concentration in tissue over concentration in serum were 1.4 +/- 0.2 (standard error of the mean). The levels in serum and prostatic tissue were above the MICs for most urinary pathogens.

Enoxacin↗
PubMed1988

[The first generation of the Saguenay population: origin, kinship, and rootedness].

The responsibility of demographic isolation for the high incidence of genetic disorders among the population of the Saguenay region of Quebec, Canada, is explored. The authors reject the view that "a few family founders are the ancestors of most of the current population....Actually, between 1838 and 1911, more than 28,000 immigrants (representing one third of the number of births) settled in Saguenay, a major fact that has to be taken into account if one sets out to explain the genetic structure of this population, particularly if one considers that most of these immigrants came from the same region and were grouped in kin-related families." (SUMMARY IN ENG AND SPA)

Americas↗
PubMed1988

Seasonal variation of ammonia-quotient in an Indian air-breathing freshwater teleost, Channa punctatus.

The ammonia-quotient, calculated from the data on the levels of ammonia excreted and oxygen consumed from the water, is a potent tool for understanding the utilization of macromolecules as metabolic fuel. The fish, Channa punctatus, utilizes more protein in the summer and spawning months for getting its metabolic energy but in the winter and post-spawning months it also utilizes other substrates like lipid and carbohydrate for its metabolic energy.

Ammonia↗
PubMed1988

[Spreading of the gene for myotonic dystrophy in Saguenay (Quebec)].

The prevalence of the myotonic dystrophy (Steinert disease) is about 1/475 in the Saguenay region, located in the North-east of the province of Québec (Canada). About 600 cases are currently known in a population of 285,000 inhabitants. This disease is an autosomal dominant disorder which causes a general muscular degeneration. Usually, it is also associated with a lower fertility, if not sterility, among the affected families. Another element of the phenotype is a higher infant mortality rate among cases. In the light of those traits, the very high prevalence of the disease in the Saguenay population becomes rather puzzling. It is the subject of this research. Using a computerized population register, we have been able to analyze the genealogies of the patients and their family history. In the overall, two basic factors account for the wide transmission of the gene: a) an immigration stream from a neighbouring region (Charlevoix) may have brought between 57 and 77 patients into the Saguenay since 1840; b) the cases proved to be by and large as fertile as controls (an average of 9.2 births among 85 affected families). The paper also presents a genealogical inference program used to ascertain cases among ancestors, along with data on the history of the gene, nuptiality, geographical and occupational mobility. In the overall, we have not been able to bring out an important selective disadvantage against the patients.

Female↗