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Biomedical subjects

M L Garg

Publications and source records attributed to M L Garg.

18 recordsLinked to original sources

Essential fatty acid metabolism in cultured human airway epithelial cells.

To characterize essential fatty acid metabolism of human airway epithelium, we examined the capacity of epithelial cells to incorporate and desaturate/elongate 18:2(n - 6) and the turnover of phospholipid fatty acyl chains in these cells. Epithelial cells were cultured for 5-7 days and incubated with [1-14C]18:2(n - 6) (1 microCi, 100 nmol). The essential fatty acid profile of the cells was readily modified by 18:2(n - 6) supplementation to culture medium. After 4 h incubation, 32 +/- 5.6 nmol of [1-14C]18:2(n - 6) was incorporated into phospholipids (65 +/- 9.5%, of which 74% was incorporated into phosphatidylcholine (PC)) and neutral lipid (31 +/- 10%) per mg protein of cultured cells. 30 +/- 8% of [1-14C]18:2(n - 6) incorporated, was converted to homologous trienes, tetraenes and pentaenes, the major products being 20:3(n - 6) and 20:4(n - 6). The conversion of 18:2(n - 6) was time-dependent and donor age-related. A higher proportion of 20:3(n - 6) and 20:4(n - 6) was incorporated into phosphatidylinositol (PI) and phosphatidylethanolamine (PE). About 10-15% of total products formed from 18:2(n - 6) was released from membrane to culture medium. Both 20:4(n - 6) and 20:5(n - 3) inhibited 18:2(n - 6) incorporation and desaturation. Rate of incorporation of 18:2(n - 6) was more than either 18:1(n - 9) or 16:0. With pulse-chase studies, the half-life of 18:2(n - 6) in PC, PI and PE was estimated to be 5.5, 6.0 and 7.3 h, respectively. These data indicate active metabolism of essential fatty acids in human airway epithelial cells. This metabolism may play a key role in the regulation of membrane properties and function in these cells.

Carbon Radioisotopes

Student peer review of diagnostic tests at the Medical College of Ohio.

Students in their clinical clerkship performed retrospective reviews of their peers' laboratory usage patterns. Data covering the patient's history and physical examination, problem list, and treatment plan had been completed by students during internal medicine and pediatrics rotations. This information, along with the first day's diagnostic orders, was provided to community medicine clerkship students who then evaluated the cost and medical necessity of diagnostic tests ordered in light of the problem information. Application of such cost control programs, before students form definitive conceptions of treatment, may contribute to more cost-conscious behavior in their future medical practice.

Clinical Laboratory Techniques

Evaluating inpatient costs: the staging mechanism.

Inpatient records at a short-term hospital over two years were analyzed according to the stage or degree of severity of their discharge diagnosis to examine their utilization of services. Patients with a more severe disease stage for surgical and medical conditions generated substantially higher total charges, ancillary charges, and had longer lengths of stay. At the 75th percentile (representing that value at which three-quarters of the cases fall below it in magnitude), increases in total charges from Stage I to II for ulcer of stomach, appendicitis, and diverticulitis were 103, 168, and 110 per cent, respectively. Ancillary charges for these diseases showed even greater increases, 167, 200, and 160 per cent, respectively. Components of ancillary charges revealed similar trends. The results suggest that a twofold review mechanism incorporating length of stay and charges, using the staging technique, would make the review procedure more discriminating in identifying cases appropriate for review.

Costs and Cost Analysis

Malignancy in rheumatic disease: interrelationships.

Patients with inflammatory arthritis and malignancy comprise two distinct populations. One group represents the chance occurrence of malignancy and rheumatic disease. These patients have symmetric polyarthritis, chiefly classic rheumatoid arthritis, and react positively to the rheumatoid factor test. There is no temporal relationship between tumor onset and rheumatic disease onset. In the second group, there may be a causal relationship between the malignancy and the rheumatic disease. These patients have asymmetric rather than symmetric arthritis and test results are negative for rheumatoid factor. There is a close temporal relationship between the onset of the tumor and the onset of the rheumatic disease. The mortality rate is significantly higher than in patients with symmetric polyarthritis. In 80 percent of women with asymmetric arthritis and malignancy, the tumor is mammary carcinoma. This indicates the advisability of a careful breast examination in this group of women.

Adult

The effects of vasectomy on the testis and accessory sex glands of the Hartley strain guinea pig.

The short term effects of bilateral vasectomy on the testis and the accessory sex glands of the guinea pig were compared with the effects of sham operation and unilateral vasectomy at 3, 5, 7, and 9 weeks after operation. The testis weights, sorbitol dehydrogenase activity, histology, epididymal sperm number, and motility were recorded. Accessory sex glands were weighed and chemically analyzed for fructose and citric acid content. The citric acid concentration of the dorsolateral prostate of the bilateral vasectomy group was significantly higher than concentrations in sham-operated and unilateral vasectomy groups at 3 weeks only. This may indicate transient hormonal derangement as a result of vasectomy. No significant differences were noted between testes of vasectomy and sham-operated groups. The unligated side testes of the unilateral vasectomy group were different from the testes of vasectomy and sham-operated groups. We conclude that interruption and ligation of the vas deferens itself has no effect on the testis of the guinea pig. Furthermore, all vasectomy experiments should include sham-operated controls.

Animals

Quality assurance in undergraduate medical education at the Medical College of Ohio.

This paper reports a four-year experience in teaching evaluation of care at a three-year medical school, the Medical College of Ohio at Toledo. Informal patient care evaluation evolved to more structured medical care evaluation in seminars and by chart audits. The introduction of professional standards review organizations prompted the teaching and evaluation of the quality and cost of primary care, especially as it applies to learning clinical tasks.

Attitude of Health Personnel

Teaching students the relationship between quality and cost of medical care.

The usefulness of hospital charges as a means of teaching medical students the relationship between the quality of the cost of medical care provided by primary care physicians (internists and family physicians) is presented. The comparative role of these two types of primary care physicians as "generators of costs" is described. The cost of hospital care provided by primary care physicians is also compared with the cost of care provided by the cardiologist, a prototype of the highest quality of secondary and tertiary care for cardiovascular diseases. Data indicate that internists generated hospital costs that were consistently higher than family physicians. Moreover, a comparison of costs generated by internists, family physicians, and cardiologists in managing patients with cardiovascular diseases revealed that cardiologists generated lower costs than the other two types of specialists. It is believed that case studies such as this will provide evidence that will enable undergraduate medical students to reflect upon their own attitudes toward their developing role as "generators of cost".

Adolescent

Alpha-linolenic acid and metabolism of cholesterol and long-chain fatty acids.

Animal studies have demonstrated that dietary 18:3n-3 reduces 20:4n-6 content in plasma and tissue lipids. At megadose levels of 18:3n-3, the reduction in phospholipid 20:4n-6 is brought about by a combination of inhibition of desaturase activities and redistribution of 20:4n-6 from phospholipids to neutral lipid pools. The shifting phenomenon is not apparent when the dietary level of 18:3n-3 is low. Dietary 18:3n-3 reduces cholesterol levels in blood and liver tissue; however, the mechanism by which this effect is mediated is not known. Further studies are warranted to investigate the role of dietary 18:3n-3 on cholesterol biosynthesis, storage, and mobilization into and from the tissues and on the secretion of cholesterol into bile. The effect of the ratio of dietary 18:2n-6 to SFA as a determinant of 20:4n-6 and lipid-lowering effects should be further explored in human subjects. It is important to elucidate whether dietary 18:3n-3 interacts with other nutrients to modulate the parameters implicated in the pathogenic processes. The optimum level of dietary 18:3n-3 required to obtain health beneficial effects needs to be determined. Specific effects of dietary 18:3n-3 on low- and high-density lipoprotein cholesterol levels also deserves further investigation before any recommendation to achieve health benefits can be made.

Animals