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Biomedical subjects

L A Lewis

Publications and source records attributed to L A Lewis.

At least 19 recordsLinked to original sources
PubMed1992

Group I introns within the nuclear-encoded small-subunit rRNA gene of three green algae.

Four group I introns from the nuclear-encoded (18S) rRNA genes of three chlorophycean green algae are described; two are in Dunaliella parva, and one each is in D. salina and Characium saccatum. The introns within the gene in the latter two organisms are located at the sites equivalent to the 5' and 3' introns of D. parva, respectively. All four introns lack open reading frames and are relatively small, 381-447 bp. Both primary- and secondary-structural features place these introns within subgroup IC1 described by Michel and Westhof. Phylogenetic relationships of the three intron-containing taxa and their relatives, as inferred from comparisons of 18S rDNA sequences, suggest that inheritance of the introns along with the gene can account for their present distribution. The discovery of these four introns, in addition to two others known to exist in other chlorophycean green algae, suggests that group I introns within the 18S rRNA gene may be relatively common in the green algae.

Base Sequence↗
PubMed1992

Classification model that predicts medical students' choices of primary care or non-primary care specialties.

To identify factors that influence students to choose primary care or non-primary care specialties, the authors surveyed the 509 graduating students at the Medical College of Georgia School of Medicine in 1988, 1989, and 1990. Using a Likert-type scale, the 404 responding students rated potential influences on their specialty choices from 1, very negative, to 7, very positive. The students choosing primary care specialties were positively influenced significantly more often by their desire to keep options open (85% versus 58%, p less than .001) and their desire for longitudinal patient care opportunities (95% versus 54%, p less than .001). Those choosing non-primary care specialties were more often influenced by their desire for monetary rewards (69% versus 35%, p less than .001) and by their perceptions of lifestyle following residency (74% versus 60%, p less than .01) and prestige of the specialty (57% versus 36%, p less than .001). The authors used multiple discriminant analysis to derive a discriminant function that would permit classification of students into primary care and non-primary care groups. The potential influences of desire for longitudinal care opportunities and desire for monetary rewards were statistically and clinically significant for all three years. Using the discriminant function, the authors correctly classified 81%, 79%, and 78% of the students' specialty choices for 1988, 1989, and 1990, respectively. The authors suggest that addressing the issue of monetary rewards will be necessary before the primary care fields again become attractive to students.

Career Choice↗
PubMed1978

Commercial national board review programs. A case study at the Medical College of Georgia.

For a long period, students have been taking national board examination review programs offered by commercial firms. The one question to which faculty and students would like the answer is, "Do the national board review programs offered by these commercial firms do any good?" Events at the Medical College of Georgia have provided an opportunity to gather data toward an answer to this question. In 1976, thirty-three medical students at the Medical College of Georgia enrolled in a commercial national board review program. Performance of these students was compared with the predicted performance of these students had they not taken the national board review program. The results suggest that the commercial review program did not notably help these students.

Education, Medical↗
PubMed1978

Effect of alfalfa meal on shrinkage (regression) of atherosclerotic plaques during cholesterol feeding in monkeys.

A semipurified diet containing 1.2 mg of cholesterol/Cal was fed to cynomolgus monkeys (Macaca fascicularis). At the end of 6 months, a group of 18 animals was killed for evaluation of atherosclerosis in the aorta and the coronary arteries. The remaining monkeys were assigned to three groups of 18 animals each and fed, during the following 18 months, semipurified diets containing 0.34 mg of cholesterol/Cal with or without alfalfa meal, or a diet consisting entirely of Monkey Chow. a decrease in cholesterolemia and plasma phospholipid levels, normalization in the distribution of plasma lipoproteins, and reduction in the extent of aortic and coronary atherosclerosis were observed in monkeys fed the semipurified diet containing alfalfa, although the intake of cholesterol remained as high as in the usual American diet. These changes, also observed in monkeys fed a chow diet almost devoid of cholesterol, suggest that alfalfa counteracts the atherogenic effect of dietary cholesterol.

Animals↗
PubMed1978

Treatment of established atherosclerosis during cholesterol feeding in monkeys.

A semipurified diet containing 43% of the calories as fat and 1.2 mg of cholesterol/cal was fed to cynomolgus monkeys (Macaca fascicularis) for 6 months; the cholesterol content was reduced to 0.34 mg/cal for the next 18 months. During the latter period, the monkeys were assigned to 4 groups of 18 animals each and received the following dietary additions: A, none (controls); B, cholestyramine (5%, w/w); C, dextrothyroxine (0.003%); and D, Wy-14,643 (0.45%). Cholestyramine normalized plasma lipid levels and reduced the size of aortic and coronary atherosclerotic lesions in spite of the high-fat, high-cholesterol intake. Dextrothyroxine reduced cholesterolemia but did not modify the extent of arterial lesions. Wy-14,643 changed neither plasma cholesterol levels nor the extent of atherosclerosis.

Acetates↗
PubMed1978

Plane xanthoma and multiple myeloma with lipoprotein--paraprotein complexing.

Clinicopathologic findings are reported of a woman with generalized plane xanthoma, multiple myeloma (IgG type K), and hyperlipemia with very high levels of serum cholesterol and triglyceride. Complexing of the serum lipoproteins and immunoglobulins had cryoglobulin properties and was separable by ultracentrifugation. Immunofluorescent studies of skin and bone marrow demonstrated deposits of IgG with low density lipoprotein apoprotein and IgG with beta-lipoprotein, respectively. Although immunosuppressive therapy resulted in return of serum IgG, lipid, and lipoprotein levels to normal, the patient died from the myeloma. Serum lipoprotein-paraprotein complexes have been demonstrated in at least 20 other cases of cutaneous xanthomatosis and myeloma. This interaction may result in an autoimmune hyperlipemia.

Adult↗
PubMed1977

The athlete's foot.

In general, painful feet can affect the performance of an athlete in any sport. To prevent skin diseases of the feet, the "Athlete's Foot" should be kept clean and dry with toenails trimmed. Properly fitting athletic shoes should be worn to avoid the formation of blisters. Wearing of sandals in locker and shower rooms, which prevents intimate contact with infecting organisms, can alleviate many of the problems that affect the feet.

Antifungal Agents↗
PubMed1976

Effect of bran and cholestyramine on plasma lipids in monkeys.

Semipurified diets whose cholesterol content varied from 34 to 120 mg/100 kcal were given to adult female cynomolgus monkeys (Macaca fascicularis) for 9 months. The intake of dietary fiber was increased through the addition of wheat, rice, or soya bran; 5% cholestyramine was given to one group of monkeys. None of the brans reduced plasma levels of cholesterol, whereas cholestyramine produced marked hypocholesterolemic effects. Triglyceride levels increased with higher cholesterol intake, but no additional changes were induced by any of the experimental diets. Plasma phospholipids were reduced by cholestyramine.

Animals↗