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Biomedical subjects

J L Dorsey

Publications and source records attributed to J L Dorsey.

At least 19 recordsLinked to original sources
PubMed1999

Dietary conjugated linoleic acid influences the immune response of young and old C57BL/6NCrlBR mice.

Aging is associated with a decline in the immune response in mammals. Conjugated linoleic acid (CLA) has been suggested to have immunoenhancing properties. We examined the influence of dietary CLA on the immune response of young and old mice. Forty young (4 mo) and 40 old (22 mo) mice consumed ad libitum diets containing 0 or 1 g CLA /100 g for 8 wk. Splenocytes from half of the mice were isolated to evaluate proliferation to concanavalin A (Con A) (0.5, 1.5, 5.0 mg/L) and phytohemagglutinin A (PHA) (5, 20, 40 mg/L) and lipopolysaccharide (LPS) (5, 15, 30 mg/L), natural killer cell (NK) activity and prostaglandin (PG)E2 and interleukin (IL)-2 production. The remaining mice were used to evaluate in vivo delayed-type hypersensitivity (DTH) skin response. There was a significant decline due to age in response to all three mitogens tested (P < 0. 05). CLA supplementation significantly increased all CLA isomers measured in hepatic neutral lipids and phospholipids (P < 0.05). Young mice fed 1% CLA had greater splenocyte proliferation in response to Con A (0.5 and 5.0 mg/L) and PHA (40 mg/L) (P < 0.05) than young mice fed control diet. Old mice fed 1 g CLA/100 g had significantly higher proliferative response to optimal concentrations of Con A (1.5 mg/L) (P < 0.001) than the mice fed the control diet. Old mice fed the control diet had significantly lower splenocyte IL-2 production than the young mice (P < 0.005). CLA-supplemented young mice had significantly higher splenocyte IL-2 production than those fed the control diet (P < 0.05). CLA had no effect on NK cell activity, PGE2 production or DTH in young or old mice. Further studies are needed to determine the mechanism of CLA-induced enhancement of IL-2 production and T cell proliferation.

Aging↗
PubMed1999

Influence of caffeine on metabolic and cardiovascular functions during sustained light intensity cycling and at rest.

This study assessed the influence of caffeine on metabolic and cardiovascular functions during sustained, light intensity cycling and at rest. Eight healthy, recreationally active adults participated in four randomly assigned, double-blind experimental trials of 60 min upright seated cycle exercise (30% VO2 max) or equivalent rest with caffeine (5 mg.kg-1) or placebo consumed 60 min prior to data collection. Gas exchange was measured by open-circuit spirometry indirect calorimetry. Global blood flow was evaluated by thoracic impedance cardiography and arterial blood pressure by auscultation. A repeated measures ANOVA indicated that pretrial caffeine increased oxygen uptake and energy expenditure rate (p < 0.05) but did not change respiratory exchange ratio. Systolic, diastolic, and mean arterial blood pressure were elevated following caffeine intake (p < 0.05). Cardiac output, heart rate, stroke volume, and systemic vascular resistance were not significantly different between caffeine and placebo sessions. For each of the metabolic and hemodynamic variables examined, the effects of caffeine were similar during constant-load, light intensity cycling and at rest. These data illustrate that caffeine's mild thermogenic influence can be mediated without a major shift in substrate oxidation mixture. Caffeine at this dosage level alters cardiovascular dynamics by augmenting arterial blood pressure.

Adult↗
PubMed1996

A critical pathway to treat proximal lower-extremity deep vein thrombosis.

To address variation in treatment of deep vein thrombosis (DVT) while maximizing the efficiency and quality of care, our institution developed a critical pathway guideline. This paper presents this critical pathway and the clinical rationale underlying its recommendations. The DVT pathway synthesizes recommendations for all aspects of patient care, including laboratory evaluation at admission, dosing and management of heparin therapy, timing of warfarin initiation, elements of patient education, discharge planning, and anticipated duration of heparinization and hospitalization. Differences among interpretations of the medical literature, patient populations, physician skills, test availability, and other variables make it unlikely that all elements of this pathway would best meet the needs of another institution. Nevertheless, the critical pathway format and the specific contents of this pathway may serve as a useful benchmark for others involved in creating clinical guidelines for this patient population.

Activities of Daily Living↗
PubMed1992

Plasma vitamin E concentrations of older infants fed cow's milk or infant formula.

Nutrition of older infants, though important for optimal brain development, is inadequately studied. The beverage choice markedly influences nutrient intake, but little is known regarding nutrition status of older infants, particularly for vitamin E. This study assessed vitamin E intakes and plasma tocopherol concentrations in two groups of healthy infants, 8 to 13 months of age, who had consumed either cow's milk (n = 45) or milk-based formula (n = 55) for a minimum of the 3 preceding months. Mean (+/- SEM) vitamin E intake was significantly lower (p < or = 0.001) by the infants who had consumed cow's milk (CMF) than by infants who had consumed formula (FF); 4.1 +/- 0.25 mg/day and 10.9 +/- 0.57 mg/day, respectively. Mean (+/- SEM) intake of linoleic plus linolenic acids was significantly lower (p < or = 0.005) by CMF infants (3.4 +/- 0.2 g) than by FF infants (9.9 +/- 1.0 g), although mean (+/- SEM) dietary vitamin E to polyunsaturated fat ratio (E/PUFA ratio) was the same in both FF and CMF infants (1.3 +/- 0.1). Plasma alpha-tocopherol concentration (mean +/- SD) was significantly lower (p < or = 0.005) in CMF than in FF infants (0.86 +/- 0.28 mg/dl vs. 1.14 +/- 0.42 mg/dl, respectively). Dietary vitamin E intakes were positively correlated (p < or = 0.05) with plasma alpha-tocopherol concentrations. No correlations were found between plasma alpha-tocopherol concentrations and total fat intake, dietary E/PUFA ratios, erythrocyte polyunsaturated fatty acids > or = C18:2, or number of hours postprandial that blood was drawn.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1978

A follow-up study of residents in internal-medicine, pediatrics and obstetrics-gynecology training programs in Massachusetts. Implications for the supply of primary-care physicians.

A questionnaire survey of physicians who had been residents in internal medicine, pediatrics or obstetrics-gynecology in Massachusetts during the years 1967-1972 was undertaken to determine that specialties they now practice and the extent to which they deliver primary care. Over 600 physicians (74 per cent) responded. Devoting more than half their practice to a primary-care specialty were only 28 per cent of the former residents in internal medicine as compared with 56 per cent of those in pediatrics and 74 per cent of those in obstetrics-gynecology. For each group the fraction of full-time equivalent primary-care physicians produced was 0.27, 0.42 and 0.39 for the internal-medicine, pediatrics and obstetrics-gynecology programs respectively. These findings indicate that, although Massachusetts is meeting the requirements of PL 94-484 concerning the percentage of residency positions in the primary-care specialties, such compliance does not guarantee an adequate future supply of primary-care practioners.

Certification↗
PubMed1978

Quality assurance through automated monitoring and concurrent feedback using a computer-based medical information system.

A computer-based medical information system (COSTAR) has been used to support a quality assurance program where the data collection is an integral part of the patient care recording activity and, therefore, does not require a separate abstracting or encoding process. This program utilizes concurrent audit to detect deficiencies in patient care, and automatic rapid feedback to the responsible provider in time to allow the provider to correct the deficiency. This system has been demonstrated to improve follow-up of throat cultures, positive for Group A Beta hemolytic streptococcus. It is well accepted by the medical staff whose practice is being audited. Because the data are collected as part of the routine operation of COSTAR, the computer monitoring and feedback have only a small incremental cost.

Boston↗
PubMed1977

Graduate education in primary care: an economic analysis.

To determine the financial requirements of an established primary-care educational program for house officers, we studied two prepaid and two fee-for-service Harvard Primary Care Program affiliated practices. Program-wide, each resident saw an average of 112 patients per month, with patient service costs of $2,580. With teaching and administrative expenses included, total monthly costs averaged $3,120 and $3,270 per trainee for prepaid and fee-for-service practices respectively. In fee-for-service practices, resident billings for patient services averaged $2,790, yielding revenues of $2,510 per month, which offset 77 per cent of total program costs. At current reimbursement rates, covering full program costs in the fee-for-service practices would require an increase of more than 40 per cent in resident-provided patient-care volume. By reducing time available for broad ambulatory experiences, such an increase would necessitate substantial program restructuring and limit opportunities for innovation in the Harvard Primary Care Program.

Costs and Cost Analysis↗
PubMed1975

The Health Maintenance Organization Act of 1973 (P.L. 93-222) and prepaid group practice plans.

Passage of the 1973 Health Maintenance Organization Act (P.L. 93-222) represents a significant effort by the Federal government to experiment with organizational change in the structure of the health care delivery system. The history of the bill is briefly reviewed. The most important sections of the bill are analyzed from the perspective of an existing prepaid group practice plan. The author concludes that the bill contains sufficiently stringent requirements that it will not result in a major increase in the number of Health Maintenance Organizations unless similar requirements are imposed on other private insurance carriers. Furthermore, significant allowance for "phasing in" will be required for the existing prepaid group practice prototype plans to qualify for Federal certification.

Costs and Cost Analysis↗