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Biomedical subjects

R Roy

Publications and source records attributed to R Roy.

At least 307 records · Page 17Linked to original sources
PubMed1990

A comparative study of Canadian nonclinical and British pain clinic subjects.

Forty-six pain clinic patients (British) were compared with 143 nonclinical subjects (Canadian) on a variety of demographic and illness variables. A subset of 43 nonclinical subjects was further compared with the 46 pain clinic patients for depression and illness behaviour. Both groups were well matched for age, sex, and marital status. The nonclinical group was better educated and had higher incomes. The nonclinical group was significantly more socially active. Low back pain, joint pain, and head and chest pain were commonly reported by both groups. Nearly 75% of subjects in both groups were aware of the diagnosis for their pain condition. On Beck Depression Inventory both groups scored in the nondepressed range. On the Illness Behaviour Questionnaire the pain clinic group scored significantly higher on disease conviction, somatization, and denial than did the nonclinical sample.

Age Factors↗
PubMed1990

Determination of nonconjugated and conjugated steroid levels in plasma and prostate after separation on C-18 columns.

An accurate method is described for analysis of C-21, C-19, and C-18 steroids as well as steroid conjugates, namely, androstane-3 alpha,17 beta-diol glucuronide, androsterone glucuronide, estradiol glucuronide, and estrone glucuronide as well as dehydroepiandrosterone sulfate and androst-5-ene-3 beta,17 beta-diol sulfate. This technique involves an extraction step, aimed at solubilizing the nonconjugated steroids as well as the steroid sulfates and glucuronides, C-18 column chromatography, permitting the separation of nonconjugated steroids and the conjugated group followed by specific hydrolysis of the glucuronide and, finally, solvolysis of the steroid sulfates. Our data indicated that using 1 ml of plasma or 1 g of prostate, good recovery of the three groups of steroids was obtained. Moreover, an accurate determination of steroids could be achieved. The plasma levels of steroids in normal adult women and men found using our technique were within the range of those previously reported by us and other authors.

Female↗
PubMed1990

Efficiency of sanitizing agents for destroying Listeria monocytogenes on contaminated surfaces.

In an effort to control the potential hazard of dairy product contamination by contact with processing surfaces, the efficiency of four commercial sanitizing agents was evaluated using the AOAC use-dilution method for their bactericidal activity at 4 and 20 degrees C against Listeria monocytogenes strain Scott-A attached on four types of surfaces (stainless steel, glass, polypropylene, and rubber). Our results indicate that all sanitizers tested were more efficient against L. monocytogenes attached to nonporous surfaces than to porous surfaces. After 10 min of contact time, the limit concentration of disinfectants was at least 5 to 10 times higher for sanitizing rubber than stainless steel or glass surfaces. Concentrations of each sanitizer needed to be higher at sanitation at 4 degrees C than at 20 degrees C to destroy L. monocytogenes attached to stainless steel, glass and rubber when surface contamination was achieved at 4 or 20 degrees C.

Disinfection↗
PubMed1990

Distributions of genetic markers in a Nebraska population.

Seven genetic marker systems were analyzed from liquid blood and dried bloodstain specimens submitted to the Nebraska State Patrol Crime Laboratory from various law enforcement agencies throughout Nebraska. The phenotypic and genotypic frequencies for the ABO, Lewis, esterase D (ESD), phosphoglucomutase (PGM), adenylate kinase (AK), adenosine deaminase (ADA), and haptoglobin (HP) systems were calculated. The results indicate that the phenotypic frequencies are generally in agreement with frequencies reported in other populations in the United States.

Blood Group Antigens↗
PubMed1989

Lipoproteins: carriers of dehydroepiandrosterone fatty acid esters in human serum.

The association between lipoproteins, cholesterol and cholesteryl esters is very well known to facilitate both the transport in plasma and the entry of these non-polar compounds into the cellular compartment. However, recent observations suggest that in addition to cholesterol, lipoproteins contain several other steroids in their lipoidal metabolite forms which may be transported in the very low, low and high density lipoproteins in human serum. Using the important androgen and oestrogen precursor, dehydroepiandrosterone (DHEA), the biosynthetic formation of lipoidal DHEA was demonstrated in human serum. Serum was also fractionated into its lipoprotein components during the course of its incubation with tritiated DHEA. A progressive movement of the label from the fraction containing the conventional steroid binding-proteins to the lipoproteins was observed with the fraction containing the low density lipoproteins demonstrating the greatest incorporation of the label. This displacement occurred simultaneous to an extensive esterification of the labelled DHEA in serum. After 6 h of incubation, approx. 90% of the radioactivity in all the lipoprotein fractions was in the lipoidal form. Very little labelled lipoidal DHEA was associated with the serum protein fraction throughout the duration of incubation. These data suggest that lipoproteins act as the carriers of lipoidal DHEA following its formation from the non-conjugate parent steroid in serum.

Cholesterol↗
PubMed1989

Formation of lipoidal steroids in follicular fluid.

The presence of high levels of lipoidal pregnenolone in follicular fluid has recently been established although no evidence has been presented concerning its possible origin. The following investigation focuses on the enzymatic conversion of non-conjugated steroids into their lipoidal derivatives in preovulatory follicular fluid obtained from women undergoing in vitro fertilization. Our observations indicated that pregnenolone, an important precursor steroid, was acylated at a similar rate as cholesterol in follicular fluid. Similar studies were subsequently conducted with serum obtained from a pool of normal women and women undergoing follicular stimulation which showed little difference to the results obtained in follicular fluid. Further studies using dehydroepiandrosterone, androst-5-ene-3 beta,17 beta-diol, estradiol and dihydrotestosterone were were also performed to monitor their respective lipoidal conversion percentages in follicular fluid which revealed a marked difference of conversion rates between steroids. The indirect identification of the lipoidal pregnenolone derivatives formed in follicular fluid was also conducted by incubating radiolabelled pregnenolone in follicular fluid. The fatty acid components of the resulting lipoidal pregnenolone derivatives showed a marked resemblance to those of cholesteryl esters formed in plasma by the enzymatic activity of lecithin:cholesterol acyltransferase. The pregnenolone derivatives were comprised predominantly of unsaturated fatty acids such as linoleate, palmitoleate, oleate, linolenate and arachidonate while saturated fatty acids, namely palmitate, constituted 20% of the total lipoidal pregnenolone.

Chromatography, High Pressure Liquid↗
PubMed1989

Presence of fatty acid esters of pregnenolone in follicular fluid from women undergoing follicle stimulation.

In the following investigation the presence of lipoidal pregnenolone derivatives in the preovulatory follicular fluid obtained from women undergoing in vitro fertilization was established. Concentrations of lipoidal pregnenolone proved to be at least twofold greater than those of the unconjugated counterpart. Indirect identification of these lipoidal pregnenolone derivatives was achieved by comparing the C-18 column, thin-layer silica gel (TLC), high performance liquid chromatography (HPLC), and gas chromatography/mass spectrometry (GC/MS) chromatographic properties of the endogenous lipoidal pregnenolone derivatives in follicular fluid with those of synthetic acyl pregnenolone esters. Lipoidal pregnenolone derivatives recovered after HPLC subfractionation were treated with alkali to hydrolyze the acyl group thus liberating nonconjugated pregnenolone. Concentrations of this steroid were then measured using radioimmunoassay upon which analysis of HPCL and gas chromatograms permitted the calculation of the individual pregnenolone ester contributions within the samples. Five lipoidal pregnenolone derivatives constituted more than 90% of the total lipoidal pregnenolone concentration observed, these derivatives being: pregnenolone oleate (30.7%), linoleate (20.7%), palmitate (20.1%), linolenate (14.8%), and palmitoleate (7.1%).

Chorionic Gonadotropin↗
PubMed1989

Cellular reactions to polyester arterial prostheses impregnated with cross-linked albumin: in vivo studies in mice.

This study was designed to assess the possible immunological responses in mice against polyester prostheses coated with albumin and previously stabilized either with cross-linked glutaraldehyde (GA), at different concentrations, or with carbodiimide (CDI). Prosthetic discs were first implanted in the peritoneal cavities of mice, and T cells and T cell subsets (helper, suppressor, la-bearing T lymphocytes) were then quantified before implantation and at 1, 2, 3 and 4 weeks post-implantation. The percentages of T cells, subsets, and the helper/suppressor cell ratio, as well as the percentage of T cells with la receptors, were similar to the control in all experimental groups. No significant difference and no correlation were observed between the groups wherever tested. Virgin and albumin-coated grafts did not induce any quantitative changes in T cell subpopulations in mice.

Albumins↗
PubMed1989

Modulation of the immunosuppressive activities by blastocoelic fluid during rabbit pregnancy.

Temporal variation in immunosuppressive activity was determined in biological samples such as embryo-foetal fluids (blastocoelic- or amino-allantoic fluid) and blood collected from pregnant and pseudopregnant rabbits. Each of the fluids to be analyzed was pre-incubated with mitogen stimulated human lymphocytes for 48 h and then inhibition of [3H]thymidine incorporation or IL-2 receptor expression was estimated. Both means of assessing immunosuppression indicated variations in the suppressive activity throughout pregnancy. This was observed in embryo-foetal fluids but not in autologous peripheral blood nor in homologous pseudopregnant blood. At days 9-13 of pregnancy, the immunosuppressive effects of blastocoelic fluids were higher than that of the autologous sera, reached a peak at days 12 and 13 and declined thereafter, to reach the lowest levels. In order to further characterize the biological activity of day-12 blastocoelic fluid and autologous serum, they were submitted to ultracentrifugation. No suppressive activity could be demonstrated in the lipoprotein fractions. But all the activity was found in the protein fraction. Precipitation with cold ethanol confirmed that the biologically active compound was a protein. Furthermore, results obtained after ultrafiltration suggest biologically active compounds of high mol. wt (greater than 300 kDa). From the above findings, we can suggest that in the rabbit, there is no pregnancy specific systemic immunosuppression. We can also infer that (1) the immuno-tolerance of the mother towards the embryo is more due to a localized effect; (2) this effect decreases with the progression of gestation and (3) a high mol. wt factor is responsible for the immunosuppression.

Allantois↗
PubMed1989

Origin and diffusion of the myotonic dystrophy gene in the Saguenay region (Quebec).

A very high prevalence (approximately 1/475 in 1985) of myotonic dystrophy (Steinert disease) is observed in the Saguenay region, which is located in the north-east part of the Province of Quebec. For various reasons, however, the literature on the subject generally associates a high degree of selective disadvantage with this gene, which seems to contradict the Saguenay data. Using a computerized regional population register, we have reconstituted patients' genealogies and family biographies. We have thus been able to study the origin of the gene and to compare the demographic behavior of patients and controls. On the whole, patients seem to be very little disadvantaged compared to controls, in terms of reproduction as well as of geographical and occupational mobility.

Female↗
PubMed1989

Pain patients and marital relations.

Fifty-one subjects with chronic pain were assessed for couple functioning utilizing the Family Adaptability and Cohesion Evaluation Scale. In addition, they completed the Beck Depression Inventory. Results revealed serious difficulty in virtually all aspects of couple functioning for the subjects. Depressed subjects reported a higher level of couple dysfunction than the nondepressed group. Duration of pain was found to be unrelated to family adaptability, family cohesion, and family stability.

Adult↗
PubMed1989

Couple therapy and chronic headache: a preliminary outcome study.

This brief report examines the factors that led to successful completion of couple therapy with 8 chronic headache patients and their spouses, as opposed to another 8 couples who dropped out of treatment. Overall, the couples who successfully completed therapy were in less strifeful marriages and were confronted with specific life change events as opposed to the couples who dropped out, who gave evidence of chronic marital difficulties. Family and couple therapy for chronic headache sufferers is recommended on a selective basis.

Adult↗