Biomedical subjects

J Andrews

Publications and source records attributed to J Andrews.

At least 217 records · Page 12Linked to original sources

PubMed1988

Results of continued monitoring of participants in the placebo-controlled trial of zidovudine for serious human immunodeficiency virus infection.

Zidovudine (AZT, 3'-azido-3'-deoxythymidine) was shown in a controlled trial to decrease the incidence of mortality, reduce the frequency of opportunistic infections, and provide other clinical benefits to patients with acquired immune deficiency syndrome (AIDS) and advanced AIDS-related complex. Two hundred twenty-nine patients who participated in the double-blind placebo-controlled trial of zidovudine were enrolled in an open-label study. As of August 31, 1987, and interim analysis indicated that patients receiving zidovudine continued to derive benefits from therapy. Survival rates of zidovudine-treated patients were higher than those that might have been expected from previous experience with similar patients. Patients continued to experience episodes of opportunistic infections; however, these infections were either of decreased severity or were more responsive to conventional therapy. The increase in median CD4 cell counts that occurred initially was followed by a gradual decline to near baseline values. Hematologic toxicities continued to be the major laboratory abnormality associated with drug administration; however, new or more frequent toxicity was not observed with more prolonged therapy. Progressive bone marrow suppression did not appear to be associated with prolonged administration. Overall, patients originally enrolled in the double-blind trial continued to receive clinical benefit from zidovudine therapy.

Acquired Immunodeficiency Syndrome↗

PubMed1988

Effects of hepatic arterial yttrium 90 glass microspheres in dogs.

A 22-micron glass microsphere called TheraSphere (Theragenics Corp., Atlanta, GA) has been developed in which yttrium 89 oxide is incorporated into the glass matrix and is activated by neutron bombardment to form the beta-emitting isotope yttrium 90 (Y 90) before using the spheres as radiotherapeutic vehicles. The injection of up to 12 times (on a liver weight basis) the anticipated human dose of nonradioactive TheraSphere into the hepatic arteries of dogs was well tolerated and produced clinically silent alterations within centrolobular areas. The hepatic arterial (HA) injection of radioactive TheraSphere also produced portal changes similar to those observed in humans after external beam therapy. While the extent of damage increased with the delivered dose, radiation exposures in excess of 30,000 cGy did not cause total hepatic necrosis and were compatible with survival. No microspheres distributed to the bone marrow and absolutely no myelosuppression was encountered in any animal. Proposed hepatic exposures to humans of 5000 to 10,000 cGy by means of these microspheres, therefore, would appear to be feasible and tolerable. Radiotherapeutic microsphere administration preceded by regional infusion of a radiosensitizing agent and/or immediately following the redistribution of blood flow toward intrahepatic tumor by vasoactive agents can potentially yield a synergistic, highly selective attack on tumors confined to the liver.

Animals↗

PubMed1988

Dantrolene in pregnancy: lack of adverse effects on the fetus and newborn infant.

Twenty malignant hyperthermia-susceptible pregnant patients were given dantrolene sodium orally for 5 days before delivery and 3 days after delivery. When cesarean section was necessary, triggering agents were avoided. No patient had a malignant hyperthermia reaction. No adverse effect of dantrolene sodium was detected by extensive testing of the fetus and neonate. The maternal predelivery dantrolene level was correlated with the noenatal cord blood dantrolene level (r = 0.837). The mean maternal predelivery dantrolene level was 0.99 +/- 0.5 microgram/ml, and the mean neonatal cord blood dantrolene level 0.68 +/- 0.3 microgram/ml. The time from the last dose of dantrolene to delivery was correlated with both the maternal dantrolene level and the neonatal cord blood level (r = 0.65). The half-life of dantrolene in the neonatal circulation was 20 hours. The controversy of oral dantrolene prophylaxis and the implications of this study with regard to further investigation are discussed.

Administration, Oral↗

PubMed1988

Calf muscle arteriovenous malformations detected by technetium-99m erythrocyte venography.

Two cases of calf muscle arteriovenous malformation in young women, presenting clinically as deep venous thrombosis, were initially detected by Tc-99m erythrocyte venography and later confirmed by arteriography. The role of this technique in the investigation of venous thrombosis is discussed, emphasizing the importance of the lateral calf view.

Adult↗

PubMed1988

CO(2) Assimilation and Activities of Photosynthetic Enzymes in High Chlorophyll Fluorescence Mutants of Maize Having Low Levels of Ribulose 1,5-Bisphosphate Carboxylase.

Photosynthetic properties were examined in several hcf (high chlorophyll fluorescence 11, 21, 42 and 45) nuclear recessive mutants of maize which were previously found to have normal photochemistry and low CO(2) fixation. Mutants usually either died after depletion of seed reserves (about 18 days after planting), or survived with slow growth up to 7 or 8 weeks. Both the activity and quantity of ribulose 1,5-bisphosphate carboxylase (Rubisco) were low in the mutants (5-25% of the normal siblings on a leaf area basis) and the loss of Rubisco tended to parallel the reduction in photosynthetic capacity. The Rubisco content in the mutants was often marginal for photosynthetic carbon gain, with some leaves and positions along a leaf having no net photosynthesis, while other leaves had a low carbon gain. Conversely, the activities of C(4) cycle enzymes, phosphoenolpyruvate carboxylase, pyruvate, Pi dikinase, NADP-malate dehydrogenase, and NADP-malic enzyme, were the same or only slightly reduced compared to the normal siblings. The mutants had about half as much chlorophyll content per leaf area as the normal green plants. However, the Rubisco activity in the mutants was low on both a leaf area and chlorophyll basis. Low Rubisco activity and lower chlorophyll content may both contribute to the low rates of photosynthesis in the mutants on a leaf area basis.

Journal Article↗

PubMed1988