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Biomedical subjects

J Arnold

Publications and source records attributed to J Arnold.

At least 253 records · Page 14Linked to original sources

Evaluation of two phenanthrenemethanols for antimalarial activity in man: WR 122,455 and WR 171,669.

Two phenanthrenemethanols, WR 122,455 and WR 171,669, were tested in man for oral tolerance, toxicity, and efficacy against Plasmodium falciparum. In healthy subjects, gastrointestinal symptoms limited single-day dosage of WR 122,455 to 800 mg and WR 171,669 to 1,260 mg. No laboratory abnormalities phototoxicity, or gastrointestinal blood loss were noted in the subjects receiving these drugs. In subjects infected with malaria, WR 122,455 cleared parasitemia when given for 1 day in doses from 440 to 880 mg; recrudescences occurred in these subjects who were infected with either chloroquine-sensitive or chloroquine-resistant P. falciparum. However, WR 122,455 at 480 mg/day for 3 to 6 days cured 9/9 cases of chloroquine-resistant and 4/4 cases of chloroquine-sensitive P. falciparum infection. WR 171,669 at 1 g/day for 3 days cured 6/6 subjects with chloroquine-resistant and 3/3 cases of chloroquine-sensitive infection. Both agents cleared parasitemia and fever promptly.

Adult↗

Possible toxic water factor in coronary heart-disease.

Many reports indicate a significant negative correlation between death-rates for coronary heart-disease (C.H.D.) and water hardness. A reverse situation exists in the twin Kansas cities, U.S.A. Kansas City, Kansas, has water which is more than twice as hard as the softened water of Kansas City, Missouri, from the same source. Serum cholesterol and triglyceride levels were similar, but blood-pressure was higher in Kansas City, Kansas, and this correlated with higher serum-sodium, lower serum-potassium, and a tenfold higher serum-cadmium. Serum calcium and magnesium levels were higher in Kansas, while copper, chromium, cobalt, and zinc were higher in Missouri. The serum studies were con ducted on two matched groups of 260 adults from each of the sample cities. Hypertension may account for the reverse C.H.D. rate noted and be cadmium related.

Blood Pressure↗

No-reflow phenomenon in the cerebral circulation of the gerbil.

The no-reflow phenomenon has been produced in the cerebral hemispheres of the gerbil by 30 minutes of bilateral carotid artery occlusion. The no-reflow phenomenon was found to develop in relation to the fall in blood pressure which occurred on release of bilateral carotid clips. Metaraminol tartrate intravenously prevented the fall of blood pressure and significantly reduced the occurrence of the no-reflow phenomenon. Metaraminol tartrate, however, did not alter the morbidity or mortality of carotid artery occlusion for 30 minutes. There is thus no support from these experiments for the view that the no-relow phenomenon plays an important functional role in the reversibility of the effects of severe cerebral ischaemia.

Animals↗

Ischaemic swelling of cerebral hemisphere in the gerbil.

Ligation of the common carotid artery in the gerbil was found to be associated with an increase in wet weight, volume, and area of the ipsilateral cerebral hemisphere. True swelling and oedema of the hemisphere occurs. This evidence suggests that it is reasonable to continue to use the gerbil as an animal model of the oedema that many accompany cerebral infarction.

Animals↗

99mTc-pertechnetate thyroid scintigraphy in patients predisposed to thyroid neoplasms by prior radiotherapy to the head and neck.

Histories, physical examinations and 99mTc-pertechnetate imaging were used to evaluate 1,452 persons who had had x-ray therapy to the neck region for benign conditions 18 to 35 years previously. Thyroid abnormalities were found in 301 patients (21%) and thyroid malignancy was found in 29% of 193 patients with abnormal studies who were explored surgically. Thyroid imaging detected 96% of these abnormalities, 40% of which would not have been unequivocally established by physical examination alone. Nuclear imaging could not distinguish benign from malignant lesions.

Adenocarcinoma↗

Depigmenting action of corticosteroids. Experimental study on guinea pigs.

The depigmenting action of corticosteroids was studied on the black skin of the guinea-pig by cutaneous applications followed by repeated histological sections. These experiments demonstrated the depigmenting action of triamcinolone acetonide and betamethasone 17-valerate. The results of this study show the influence of concentration and chemical formula of the corticosteroids on the process of depigmentation. The histological study did not reveal any particular morphological aspect of melanocytes capable of suggesting a mechanism of action by these chemical compounds at the cellular level.

Adrenal Cortex Hormones↗