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R McDonald

Publications and source records attributed to R McDonald.

159 records · Page 9Linked to original sources
PubMed1939

After-Cataract.

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Journal Article↗
PubMedDate not supplied

Long-term effects on plasma lipids of diet and drugs to treat hypertension. Treatment of Mild Hypertension Study (TOMHS) Research Group.

OBJECTIVE: - To compare long-term plasma lipid changes among 6 antihypertensive treatment interventions for stage I (mild) hypertension. DESIGN: - Multicenter, randomized, double-blind, parallel-group clinical trial. SETTING: - Four academic clinical research units in the United States. PARTICIPANTS: - A total of 902 men and women, aged 45 to 69 years, with stage I diastolic hypertension (diastolic blood pressure <100 mm Hg), recruited from 11914 persons screened in their communities. INTERVENTIONS: - Participants were randomized to 1 of 6 treatment groups: (1) placebo, (2) beta-blocker (acebutolol), (3) calcium antagonist (amlodipine), (4) diuretic (chlorthalidone), (5) alpha1-antagonist (doxazosin), and (6) angiotensin-converting enzyme inhibitor (enalapril). All groups received intensive lifestyle counseling to achieve weight loss, dietary sodium and alcohol reduction, and increased physical activity. MAIN OUTCOME MEASURES: - Changes in plasma total cholesterol, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, and triglycerides from baseline to annual visits through 4 years. RESULTS: - Mean changes in all plasma lipids were favorable in all groups. The degree of weight loss with fat-modified diet and exercise was significantly related to favorable lipid changes. Significant differences (P<.01) among groups for average changes during follow-up in each lipid were observed. Decreases in plasma total cholesterol and LDL cholesterol were greater with doxazosin and acebutolol (for plasma total cholesterol, 0.36 and 0.30 mmol/L [13.8 and 11.7 mg/dL], respectively), less with chlorthalidone and placebo (0.12 and 0.13 mmol/L [4.5 and 5.1 mg/dL], respectively). Decreases in triglycerides were greater with doxazosin and enalapril, least with acebutolol. Increases in HDL cholesterol were greater with enalapril and doxazosin, least with acebutolol. Significant relative increases in plasma total cholesterol with chlorthalidone compared with placebo at 12 months were no longer present at 24 months and beyond, when mean plasma total cholesterol for the chlorthalidone group fell below baseline. Analyses of participants continuing to receive chlorthalidone throughout the 4 years of follow-up indicated this was not due solely to an increasing percentage of participants changing or discontinuing use of medication during follow-up. CONCLUSIONS: - Weight loss with a fat-modified diet plus increased exercise produces favorable long-term effects on blood pressure and all plasma lipid fractions of adults with stage I hypertension; blood pressure reduction is enhanced to a similar degree by addition of a drug from any one of 5 classes of antihypertensive medication. These drugs differ quantitatively in influencing the degree of long-term favorable effects on blood lipids obtained with nutritional-hygienic treatment.

Acebutolol↗
PubMedDate not supplied

Dissociation of the medial prefrontal, posterior parietal, and posterior temporal cortex for spatial navigation and recognition memory in the rat.

Rats with lesions of the medial prefrontal, posterior parietal, or posterior temporal cortex were tested in five spatial navigation tasks, which varied in egocentric or allocentric demands, a visual discrimination task, and two delayed nonmatching-to-sample tasks. Rats with prefrontal lesions were impaired at every spatial navigation task, whereas rats with posterior parietal lesions had selective spatial navigation impairments. Rats with prefrontal lesions were also impaired at a visual delayed nonmatching-to-sample task, as they were unable to learn the task, even with no delay. The results are consistent with the idea that the basic plan of mammalian cortex includes prefrontal, posterior parietal, and posterior temporal regions, each of which have generally similar functions across mammalian taxa. There are, however, species-typical differences that reflect specific ecological pressures on the development of the different regions.

Animals↗
PubMedDate not supplied

Interparental conflict and child adjustment: testing the mediational role of appraisals in the cognitive-contextual framework.

Children's appraisals of interparental conflict consistently have been associated with adjustment problems, but the processes that give rise to this association are not well understood. This paper proposes that appraisals of threat and self-blame mediate the association between children's reports of interparental conflict and internalizing problems, and tests this mediational hypothesis in two samples of children, one drawn from the community (317 ten- to fourteen-year-olds) and the other from battered women's shelters (145 ten- to twelve-year-olds). Results indicate that perceived threat mediates the association between interparental conflict and internalizing problems for boys and girls in both samples, and self-blame mediates this association for boys in both samples and girls in the shelter sample. Perceived threat and self-blame do not mediate links with externalizing problems, and there is no evidence of a moderating effect of appraisals on the association between conflict and child adjustment. Implications for understanding the mechanism by which exposure to interparental conflict could lead to child maladjustment are discussed.

Adaptation, Psychological↗