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R Parent

Publications and source records attributed to R Parent.

50 records · Page 3Linked to original sources
PubMed1982

Variations of cardiac rate and hemodynamic criteria of rejection.

Since heart rate influences the values of many hemodynamic parameters, the authors have examined the effect of heart rate variations noted after cardiac transplantation on the hemodynamic criteria of rejection. They have undertaken serial studies at intrinsic rate and at a paced atrial rate of 150 beats/min in 11 resting homotransplanted dogs. The authors analysed cardiac index, stroke volume, peak velocity, acceleration, stroke power and stroke work. Results at intrinsic and paced atrial rates were compared during each of three phases of postoperative evolution: phase II (2 to 3 days after transplantation), phase III (4 to 5 days) and phase IV (6 to 7 days postoperatively). Phase II, being the period of maximum recovery, served as a baseline for comparing the cardiac parameters in phases III (the initial phase of rejection) and phase IV (24 hours before death). The authors found that the patterns of change were similar at intrinsic and paced atrial rates and concluded that heart rate variation does not significantly influence the hemodynamic criteria of rejection.

Animals↗
PubMed1981

Protection of the myocardial homograft. 1. The cooling bag.

Because severe cardiac insufficiency follows orthotopic heart transplantation, the authors have evaluated protection of the homograft provided by a cooling and isolating bag during the operative period of ischemia and subsequently its effect on cardiac function. In one group or four dogs hearts were transplanted without using hypothermia. In the second group, seven hearts were excised, immediately cooled by immersion in saline at 4 degrees C and orthotopically homotransplanted. In the third group, six hearts were immersed in saline and then isolated in a cooling bag until transplantation had been completed. Cardiac function in all animals was evaluated at rest, 3, 24 and 48 hours after operation. In group 1, lowering of the temperature was minimal and all animals died immediately after operation. In group 2, the myocardial temperature, which had been lowered to 13 degrees C by immersion, had risen to 25 degrees C after 17 minutes. In group 3, the myocardial temperature was maintained at 13 degrees C up to the time the aortic clamp was removed. Three hours after operation, the cardiac performance of group 3 was much better than that of group 3 was much better than that of group 2 as demonstrated by an increase of cardiac output (39%), stroke volume (44%), mean systolic ejection rate (25%), maximum systolic flow (28%), peak velocity (26%), maximum acceleration (20%), left ventricular power (32%) and left ventricular work (47%). In the following days, cardiac function of groups 2 and 3 improved and the disparity between then decreased. These results demonstrate that the cooling bag, while offering technical advantages, maintains profound hypothermia in the donor heart and substantially improves the performance of the homograft in the immediate postoperative phase.

Animals↗
PubMed1976

[Non-specific effects of a drug study in hypertensive patients].

During the first phase of a drug study, 33 hypertensive patients received 2 placebo tablets daily for 2 weeks as the sole treatment. Analysis of the blood pressure readings during this placebo phase shows that the study in itself creates a psychological climate which tends to decrease blood pressure. This effect should be taken into account when analyzing results of drug studies; only in studies with a double blind design is drug effect adequately judged.

Adult↗
PubMedDate not supplied

[Drugs, Poverty and HIV: results regarding a provincial needle exchange program in Point de Repères, Quebec].

In this study (n = 200), the characteristics of IDUs participating in a provincial needle exchange program (NEP) for more than 2 years (> 2 years) were compared with those of IDUs having participated for less than 2 years (< or = 2 years). Compared to the < or = 2 years, the > 2 years were more often recipients of welfare (RC: 4.7), especially among the HIV-positive (RC: 62.0); tried quitting drugs more frequently (RC: 3.8); more often recommended the NEP to other IDUs (RC: 3.1); and more often requested being given shelter and longer opening hours (RC: 3.6). These results highlight the urgent need to improve and develop transitional and support services for the > 2 years. Preventive interventions that would reach out to the < or = 2 years where they live should also be implemented in close collaboration with organizations involved in mental health and drug use prevention.

Community Participation↗
PubMedDate not supplied

Risk behaviours and HIV infection among men having sexual relations with men: baseline characteristics of participants in the Omega Cohort Study, Montreal, Quebec, Canada.

OBJECTIVE: To describe characteristics of men having sex with men (MSM) participating in the Omega Cohort, to describe HIV-positive participants at baseline interview, and to estimate HIV incidence. METHODS: The Omega Cohort is a study on the incidence and psychosocial determinants of HIV infection among MSM living in Montreal. MSM complete a questionnaire and are tested for HIV every six months. RESULTS: During the previous six months, 31% and 12% of 810 participants (mean age = 33 years) reported unprotected anal sex with regular and casual partners, respectively. Eight participants (0.98%) were HIV-infected at baseline. HIV incidence was 0.89 per 100 person-years (7/787 person-years) [95% confidence interval: 0.36-1.83]. CONCLUSION: A significant proportion of participants reported current risk behaviours. Despite this, HIV incidence is relatively low. It is important to target MSM who do not practice safe sex and to encourage those practicing safe sex to sustain these behaviours.

Adult↗
PubMedDate not supplied

[Myocardial protection of the homograft. III - Evaluation of ventricular fibrillations with hypothermic coronary perfusion (author's transl)].

The homotransplanted heart is in severe failure in the immediate post-operative period, secondary to ischemia inherent to the technic of orthotopic transplantation. The present work was carried out to investigate if ventricular fibrillation followed by cold coronary perfusion could protect the homograft during implantation by evaluating the post-operative cardiac performance. In the control group, 7 hearts were excised, immediately immersed in physiological saline at 5 degrees C, and homotransplanted. In a second group of 4 grafts, ventricular fibrillation was induced and the coronary bed was perfused immediately with cold (5 degrees C) extracellular solution for a period of 10 minutes before orthotopic implantation. All animals were prepared at the end of surgery for hemodynamic studies to be carried out 3, 24 and 48 hours post-operatively in the resting state. In group I, the myocardial temperature dropped to 13.5 degrees C in 14.5 minutes. In group II, the hypothermia by perfusion was more rapid and deeper (11 degrees C within 10 minutes). Three hours post-operatively, cardiac function of group II was superior to that of group I as demonstrated by the increase of cardiac index (39%), stroke volume index (41%) mean systolic ejection rate index (44%), maximum systolic flow index (58%), maximum acceleration index (36%), stroke power index (88%), stroke work index (67%). Twenty-four and forty-eight hours post-operatively the cardio-vascular function improved in both groups but remained superior in group II. These results demonstrate that ventricular fibrillation followed by cold coronary perfusion increases protection of the homograft during the initial period of implantation.

Animals↗