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Biomedical subjects

C M Lee

Publications and source records attributed to C M Lee.

At least 361 records · Page 20Linked to original sources
PubMed1978

The Health Science Institute: an experience in learning.

The Health Science Institute of Howard University was initiated during the summer of 1973 by students and faculty members in the Colleges of Liberal Arts and Pharmacy and Pharmacal Sciences to address one of the major problems related to the overall poor status of health-care delivery for residents of the nation's underserved areas-the critical health manpower shortage.

Academies and Institutes↗
PubMed1977

Iron metabolism in Trypanosoma lewisi infection: serum iron and serum iron-binding capacity.

Progressive changes in iron levels, total iron binding capacity and hematocrit values in sera of rats infected with Trypanosoma lewisi are described. The host dietary group were: (1) complete or full complement; (2) iron-deficient, and (3) pair-fed or calorically restricted. The hematocrit values of T. lewisi-infected rats given the various diets were not significantly different from those of the controls. The decrease in total iron binding capacity (TIBC) of rats inoculated with T. lewisi and fed complete and pair-fed diets ranged up to 15% over uninfected controls. TIBC levels in rats fed an iron-deficient diet and inoculated with T. lewisi ranged up to 32% over uninfected controls. TIBC levels of deficient infected rats were significantly different from the controls from day 90 to infection to the end of the observation period. Serum iron (SI) values of non-infected rats regardless of dietary regimen showed significantly higher values than T. lewisi-infected animals between days 95 and 120. The average SI value, for this period, in adequately fed control rats was 204 +/- 7 microgram/100 ml as compared to 172 +/- 5 microgram/100 for trypanosome-infected rats. SI levels of rats on a pair-fed diet and infected with T. lewisi decreased to 17% over uninfected controls. SI levels of animals on an iron-deficient diet and infected with T. lewisi decreased up to 76% over uninfected controls.

Animals↗
PubMed1976

Effect of malnutrition on susceptibility of mice to Trypanosoma musculi: vitamin A-deficiency.

Vitamin A-deficiency was studied in mice infected with Trypanosoma musculi. Irrespective of diet, trypomastigotes (trypanosomes) appeared in peripheral tail blood of all inoculated mice after 6-day incubation periods. On the average, vitamin A-deficient mice had parasitemias about 10 times greater than animals fed a complete diet and 8 times pair-fed controls. Parasitemias lasted longer in vitamin-deficient hosts, and reached a maximum five days later than those from control hosts.

Animals↗
PubMed1976

Freeze-etching observations of trophozoites of pathogenic Entamoeba histolytica.

Pathogenic Entamoeba histolytica trophozoites were studied by the freeze-etching (FE) technique of electron microscopy. Surface replicas of intact cell membranes were highly convoluted with numerous invaginations, evaginations, and undulations. Sperical depressions and elevations varying from 0.5 mu to 1.0 mu in diameter were commonly present on the external cell membrane and appeared to represent an extracellular secretory mechanism of trophozoites. Cleaved surfaces of amebae exhibited a granular and lumpy cytoplasm in which there were many vesicles and vacuoles that ranged in diameter from 0.2 mu to 9.0 mu. Some vacuoles contained tightly enveloped bacteria, while others contained bacteria and host cytocomponents. Occasional vesicles and vacuoles appeared to be fused to each other. Replicas of FE nucleus were enclosed by double nuclear membranes which were fenestrated by numerous sperical pores measuring approximately 640 A in diameter and spaced at intervals of 650 A. Counts of nuclear pores were possible and indicated 35 pores per square micron on the nuclear envelope. Golgi apparatus, mitochondria and well formed endoplasmic reticulum were absent in FE replicas. This was in agreement with electron microscope observations on thin sections previously reported by other investigators.

Animals↗
PubMed1976

Antidepressant and anticonvulsant activity of 1-(5-phenyl-4-oxazolin-2-yl)-4-substituted piperazines.

1-(5-Phenyl-4-oxo-2-oxazolin-2-yl)-4-substituted cinnamoylpiperazines and 1-(5-phenyl-4-oxo-2-oxazolin-2-yl)-4-carbamoylpiperazine and derivatives were synthesized and evaluated for antidepressant activity in the mouse Dopa potentiation test. 1-(5-Phenyl-4-oxo-2-oxazolin-2-yl)-4-carbamoylpiperazine and derivatives were further evaluated for anticonvulsant activity in the audiogenic seizure test in mice.

Acoustic Stimulation↗
PubMed1975

Trypanosoma lewisi, Trypanosoma rhodesiense: mitotic activity in normal and folic acid deficient rats.

Ten experiments were performed to compare mitotic activity in livers of rats infected with Trypanosoma rhodesiense and Trypanosoma lewisi. The host dietary groups were: (1) complete of full complement; (2) folic acid deficient, and (3) pair-fed or calorically restricted. Liver mitotic counts of T. lewisi-infected rats fed complete and pair-fed control diets showed a high degree of significance over that of control rats. From days 35 to 55, liver mitotic counts of T. lewisi-infected rats deficient in folic acid showed an average of 16 +/- 2 mitotic phases as compared to 9 +/- 2 for livers of uninfected animals. Liver mitotic counts of T. rhodesiense-infected and non-infected rats fed complete and pair-fed control diets showed that there were essentially no differences in the mitotic counts from that seen in liver from control, uninfected animals. On day 25 (day 5 of infection), folic acid-deficient infected rats showed a significantly higher number of dividing cells than the controls. Folate was measured in isolated, washed T. lewisi and T. rhodesiense cells. T. lewisi and T. rhodesiense contained 9.6 ng folate per 10(8) cells and 6.2 ng of folate per 10(8) cells respectively. Metabolic products of T. lewisi contained an average of 0.51 ng of folate per 10(8) trypanosomes. T. rhodesiense metabolic products contained 0.3 ng of folate per 10(8) trypanosomes.

Animals↗
PubMed1975

Trypanosoma rhodesiense: folate levels in sera and tissues of normal and folic acid-deficient rats.

An experimental model composed of the folic acid deficient Sprague-Dawley rat and Trypanosoma rhodesiense was used to study folate levels in sera and tissues. Serum folate levels in well fed rats inoculated on day 21 averaged 21 plus or minus ng/ml; well fed normal rats averaged 18 plus or minus 4 ng/ml. In rats given the pair-fed control diet, serum folate levels averaged 17.2 plus or minus 4 ng/ml for trypanosome-free animals and 20.2 plus or minus 3 ng/ml for infected ones. In rats given the folic acid-deficient diet, serum folate levels averaged 8.6 plus or minus 2 ng/ml for noninfected control animals and 9.3 plus or minus 2 ng/ml for trypanosome-infected ones. Regardless of diet, the infected animals inoculated on day 56 had higher serum folate levels over the controls on the last day of observation (day 5 of infection). Livers from rats fed complete and pair-fed diets and inoculated on day 21 showed no significant differences in folate content when compared to control animals. However, livers of rats on a deficient diet showed significantly more folate when compared with uninfected controls, reaching a maximum of 362% of day 25. Liver folate levels of rats (regardless of the dietary regimen) inoculated on day 56 showed significantly higher values than the controls on day 60. Irrespective of the time of inoculation or diet, brain and spinal cord of T. rhodesiense-infected rats had significantly higher folate values than their controls on day 5 of infection. The folate level of the brain and spinal cord, at this time, ranged up to 58 and 107% respectively.

Animals↗
PubMed1975

Ultrastructure of Trypanosoma duttoni.

Trypanosoma duttoni exhibits the typical trypanosome morphology in that it is bounded by a unit membrane which included its anterior flagellum; it is surrounded by a framework of suppellicular fibrils, and it contains a nucleus and the posteriorly located kinetoplast-blepharoplast structures along with cytoplasmic organelles (mitochondria, Golgi, and enoplasmic reticulum). Very prominently displayed in T. duttoni is the contractile vacuole, which has not previously received wide-spread recognition. The kinetoplast is clearly continuous with mitochondria in some cases. Inclusion bodies are categorized into three distinct types, none of which can be conclusively designated as the very popular volutin granules, without cytochemical evidence. The existence of a third tubule among peripheral tubule doublets of the flagellum is observed.

Animals↗
PubMed1975

Train-of-four nerve stimulation in the management of prolonged neuromuscular blockade following succinylcholine.

Four patients, all possessing an atypical form of plasma cholinesterase, developed prolonged paralysis following succinylcholine administration. The clinical management of all four cases was facilitated by monitoring the train-of-four stimulus. All patients showed marked "fade" of the train-of-four ratio, the initial ratios of the fourth to the first twitches being 50 per cent or less, indicating variable degrees of nondepolarizing neuromuscular blockade. Reversal of paralysis with anticholinesterase agents was completely successful in three cases, but only partially effective in the fourth because of the probable presence of a mixture of both depolarizing block and nondepolarizing block. In such a situation, caution in the interpretation of the train-of-four ratio is necessary, since this test measures only the nondepolarizing component of the block. Whether or not reversal with anticholinesterase drugs is attempted, clinical estimates of neuromuscular function, such as head lift, vital capacity, and inspiratory force, must be carefully correlated with train-of-four values. If reversal is attempted, the brief action of edrophonium provides a useful clinical trial.

Adolescent↗