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Biomedical subjects

E C Nelson

Publications and source records attributed to E C Nelson.

At least 127 records · Page 7Linked to original sources
PubMed1981

The Cooperative Information Project: Part 1: A sentinel practice network for service and research in primary care.

This is the first of two papers describing the Primary Care Cooperative Information Project (COOP Project), a program that integrates the interests of community physicians, medical school faculty, and health policymakers. This integration has been accomplished through the uniting of 44 rural medical practices in Maine, New Hampshire, and Vermont with faculty at Dartmouth Medical School in clinical research, quality assurance, practice management, and continuing medical education activities. This paper describes the structure, goals, and history of the COOP Project, together with the design, cost, and output of its computerized medical information system.

Family Practice↗
PubMed1980

Identification of a decarboxylation product of retinoic acid.

The oxidative decarboxylation of retinoic acid was investigated utilizing a model system consisting of all-trans-retinoic acid, H2O2 and horseradish peroxidase. The decarboxylation products were purified by high-performance liquid chromatography on bonded, octadecylsilane columns. Based on mass spectral, nuclear magnetic resonance, ultraviolet and Fourier transform infrared analyses, the major decarboxylation product was identified as a 4-oxo-C19 aldehyde with a hydroxyl group on the side chain at C9, specifically 8-(2,6,6-trimethyl-3-oxocyclohex-1-enyl)2,6-dimethyl-6-hydroxyoctatrienal.

Aldehydes↗
PubMed1979

The oxidation and decarboxylation of retinoic acid by horseradish peroxidase.

The decarboxylation of retinoic acid by horseradish peroxidase was investigated. A marked increase in the yield of products was obtained. However, the data indicated the reaction was a nonenzymatic, heme catalyzed peroxidation. Previously reported requirements for phosphate, oxygen and ferrous ion were eliminated when hydrogen peroxide was provided. Peroxide also eliminated the EDTA and cyanide induced inhibition of the phosphate dependent system. In the presence of hydrogen peroxide, horseradish peroxidase was not essential to the reaction; heme equivalent amounts of hemoglobin decarboxylated retinoic acid with equal facility. However, hemoglobin was ineffective in the absence of hydrogen peroxide. Attainment of 50--60% decarboxylation represented complete utilization of the available retinoic acid. Thus the products of the reaction can be divided into two groups, products of retinoic acid oxidation and products of an oxidative decarboxylation of retinoic acid.

Decarboxylation↗
PubMed1979

Solvent effects on the time-dependent photoisomerization of methyl retinoate.

The photoisomerization of methyl all-trans-retinoate is dependent upon both solvent polarity and irradiation time. The all-trans-isomer isomerizes most rapidly in solvents of high polarity. Methyl 11-cis-retinoate is maximally produced after three hours in dimethyl sulfoxide, while it is not formed to an appreciable extent in heptane. Methyl 13-cis-retinoate forms maximally after two hours in heptane, then decrease in concentration by one-half to about the same level maximally formed in dimethyl sulfoxide. The solvent and time dependences of the other isomers are presented to allow selection of conditions for maximal production of desired isomers. The results for methyl retinoate appear applicable for retinoic acid.

Chemistry, Organic↗
PubMed1978

Effect of age and dietary fat level on fatty acid oxidation in the neonatal pig.

A total of 35 pigs were obtained by cesarean section, placed in individual sterile isolators, and randomly allotted to treatment groups. Thirty pigs received purified, isoenergetic liquid diets containing 2 or 32% butterfat (dry matter basis) and were killed at 1, 7, or 21 days of age. Five pigs were killed at 2 hours post delivery and received no diet. Twenty-one-day old pigs showed a tendency for higher weight gain and feed consumption when consuming the 32% fat diet although the differences were not significant. The rate of oxidation of [U-14C]palmitate to CO2 and acid soluble products was measured in homogenates of liver, kidney, heart, and leg muscle (biceps femoris) from pigs 0, 1, 7, and 21 days of age. The relative rates of oxidation of [U-14C]myristate, [U-14C]palmitate, and [U-14C]stearate were measured in homogenates of liver from 7-day old pigs. Palmitate oxidation was stimulated by carnitine in all four tissues and the rate of carnitine-stimulated palmitate oxidation to acid soluble products in heart and to CO2 in liver was higher in tissues from pigs consuming the 32% fat diet. The rate of palmitate oxidation increased with age in liver, kidney and leg muscle tissues and was maximum at 21 days in kidney and leg muscle and at 7 days in liver. The rate of palmitate oxidation in heart tended to decrease with animal age. In homogenates of liver from 7-day old pigs, palmitate was oxidized at a faster rate than stearate or myristate. The activities of carnitine palmitoyltransferase (CPT) (EC 2.3.1a) and succinate dehydrogenase (EC 1.3.99.1) in mitochondria isolated from liver, kidney, heart, and leg muscle did not vary considerably with age although CPT activity tended to be higher in those tissues from pigs consuming the high fat diet. Changes in the rate of palmitate oxidation with age tended to parallel changes in the level of mitochondrial protein per g of wet tissue and suggested an increased ability to utilize fat as an energy substrate during early development of the neonatal pig.

Aging↗
PubMed1978

Impact of patient perceptions on compliance with treatment for hypertension.

Patient noncompliance with medical regimens is a major obstacle in achieving hypertension control. In this study the relationships between patients' perceptions of health, disease and medical treatment and compliance were examined in personal interviews with 142 patients under treatment for hypertension. Compliance was measured in terms of blood pressure control, self-reported medication-taking, and appointment keeping. A multivariate log linear technique was used to control confounding. Blood pressure control was found to be associated with the perceived effficacy of the antihypertensive regimen, having medications prescribed for other chronic conditions, a high level of anxiety when hypertension was first diagnosed, the impact of hypertension and its treatment on lifestyle, and a higher educational level. For self-reported medication-taking, the perceived severity of hypertension, having medications prescribed for other chronic conditions and older age were predictive. Blood pressure control and self-reported medication-taking were highly correlated with each other(p = .02). Older age and being employed were the only variables that contributed independently to improved appointment keeping behavior. From these findings, it might be expected that emphasis on the effectiveness of treatment and on the potential threat posed by hypertension would motivate improved blood pressure control.

Aged↗
PubMed1978

Lipid metabolism in laying hens. The relationship of plasma lipids and liver fatty acid synthetase activity to changes in liver composition.

Plasma and liver samples were taken from a random sample of caged commercial hybrid layer hens which had been in egg production for fifteen months. The concentration of plasma and liver lipids and the activity of liver fatty acid synthetase (FAS) were measured in laying hens with liver weight of 20 to 53 g. Liver total lipid, water, non-lipid, and cytosolic fractions, which are the four major liver components, increased linearly with respect to wet liver weight. FAS activity increased with all liver components. Accumulation of lipid in the liver did not inhibit FAS activity. Total cholesterol, free cholesterol, esterified cholesterol, triglycerides, and phosphorous were measured on each plasma sample. Multiple regression analysis showed that all plasma lipids, except cholesterol esters, were related cubically with increasing wet liver weight and cytosolic protein.

Animals↗
PubMed1977

Effect of dietary fat level on growth and lipogenesis in the colostrum deprived neonatal pig.

Thirty male neonatal pigs were obtained by cesarean section and randomly allotted from littermate groups to three diets containing 2%, 17%, and 32% fat on a dry matter basis. Butterfat was used to replace glucose in the isoenergetic liquid, semipurified diets. Each pig was placed in a sterile isolator and fed ad libitum five times daily. After 14 days, pigs were weighed, killed, and samples of liver and backfat were obtained. The carcass of each pig was ground and samples obtained for determination of total body fat and protein. An increase in the level of dietary fat resulted in a significant increase in 14 day weight gain and a tendency for improved feed efficiency. These results demonstrate not only that the neonatal pig can utilize semipurified liquid diets high in butterfat content, but also that energy from butterfat appears to be used as efficiently as energy from glucose from growth purposes. Increasing dietary fat level decreased the activity of fatty acid synthetase and citrate cleavage enzyme in adipose tissue and liver, and decreased the activity of malic enzyme in adipose tissue. The specific activities of these three enzymes were higher in adipose tissue than in liver.

Animals↗
PubMed1975

Financial impact of physician assistants on medical practice.

A study of revenues generated and expenses incurred by 12 physician assistants (MEDEX) who had held salaried positions for at least one year was conducted to determine their financial impact on primary-care practices. Daily charge logs were used to make annual estimates of MEDEX-generated revenues. One method of estimating annual revenues produced a mean of $28,190 per year, and a second method yielded a figure of $30,210 per year. Financial statements were used in two different ways to estimate annual expenses related to the employment of the MEDEX. One procedure indicated average costs of employment were $15,900, and the other $20,100. Ten of the 12 practices in the study experienced substantial gains of estimated revenue over expenses ascribed to the activities of the MEDEX.

Costs and Cost Analysis↗
PubMed1975

A study of the validity of the task inventory method of job analysis.

To enhance the efficient utilization of health providers, medical care researchers are increasingly concerned with the measurement of task performance. One job analysis methodology that is widely used is the task inventory technique, characterized by retrospective self-reporting. The purpose of this study was to validate the task inventory method by using the observational technique. Two data collection instruments were developed, a Task Inventory and an Observer Check List; both contained the same set of task statements. Trained observers shadowed 13 primary care physicians in their offices for one week recording the frequency and duration of task performance on the Observer Check Lists. At the end of the week, the 13 physicians completed a Task Inventory indicating how often they had performed each task in their offices and how long it normally took. The observers' and physicians' respective sets of data were analyzed to determine the degree of agreement. The results indicate that the agreement is not sufficient between the task data obtained by the two different methods to conclude that one is substitutable for the other. The validity of the Task Inventory method is therefore not supported by the results.

Evaluation Studies as Topic↗
PubMed1975

Impact of physician's assistants on patient visits in ambulatory care practices.

The addition of a physician's assistant to an ambulatory care practice increases the practice's productivity. Practices using physician's assistants (medexes) had a 12% increase in the number of patient visits during the first year of training and 1 3/4 years later had an average increase of 37%. The medex by himself provided care to 28% of the patients and, in company with the physician, to another 10%. No consistent changes across practices were noted in patient waiting times or time physicians spend with patients.

Acute Disease↗