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Biomedical subjects

D L Fisher

Publications and source records attributed to D L Fisher.

At least 55 records · Page 3Linked to original sources
PubMed1982

Cultivation of mouse embryos explanted at 11 days.

A method for cultivation of 11-day mouse embryos (plug day = day 0) is presented. Competence of the visceral yolk sac and serum dilutions were tested. Eleven day mouse embryos were cultivated for 24 hours with the visceral yolk sac either opened or left intact. Fetal calf serum (FCS) at 0%, 25%, and 50% dilutions balanced with Waymouth's medium was used as cultivation medium. Viability and growth of the embryos were evaluated by heart rate at 6 hours, and protein accumulation and differentiation at 24 hours. At 6 hours, best results were found in those embryos with the visceral yolk sac intact. Serum dilutions at this time were not important for viability. At 24 hours, only those embryos cultivated with the visceral yolk sac opened were alive. Significant increase in viability was obtained when a 50% dilution of FCS was used. There was a significant increase in protein accumulation for viable embryos at 24 hours.

Animals↗
PubMed1981

Accumulation of DNA, RNA, and protein by cultured rat embryos following maternal administration of a teratogenic dose of trypan blue.

The effect of trypan blue on the rates of DNA, RNA, and protein accumulation in rat embryos was investigated using a system of whole embryo culture. Embryos were isolated on the 10th gestational day (sperm day = Day 0) either 4 or 24 hr after maternal injection. The cultivation period was for 24 or 42 hr. The rate of DNA and RNA accumulation in the embryo following either a 4- or 24-hr previous maternal treatment was significantly decreased at at both 24 and 42 hr of cultivation. Protein values were significantly reduced after a 4-hr maternal exposure, but only slightly reduced after a 24-hr maternal exposure. No significant differences in DNA, RNA, or protein content were observed at the beginning of cultivation, following either a 4- or 24-hr previous maternal treatment. The percentage of embryos establishing a visceral yolk sac circulation was greatly reduced, and this supports the conclusion that trypan blue interferes with yolk sac function. The most obvious teratogenic insults include failure of neuropore closure, retention of a dorsiflexed position, and cranial edema.

Animals↗
PubMed1981

An in vivo/in vitro evaluation of teratogenic action.

Several compounds were administered to pregnant Wistar-derived rats either 24 or four hours prior to the recovery of day 10 embryos for in vitro culture in Waymouth's medium and fetal calf serum. The compounds tested were 2-amino-1,3,4-thiadiazole (thiadiazole), cadmium sulfate, 1,2-dibromo-2,2-dichloroethyl dimethyl phosphate (dibrom), 2-(sec-Butyl)-4,6-dinitrophenol (dinoseb), led nitrate, polybrominated biphenyls (PBB), sodium arsenate, and trypan blue. After 24 hours in culture, two thirds of the embryos were recovered for examination. The remaining one third were continued in culture until 42 hours. Recovered embryos were examined for rotation of the embryonic axis, heart rate, establishment of the visceral yolk sac circulation, somite number, growth of the limb buds, closure of the neural tube, and development of the allantois and amnion. All tested compounds inhibited the rate of development in vitro.

2,4-Dinitrophenol↗
PubMed1980

Effects of hormones on post-implantation mouse embryos in vitro. I. Insulin.

Day 9 mouse embryos were cultured in 50% fetal calf serum and 50% Waymouth's medium supplemented with various amounts of insulin. Unmodified medium contained approximately 25% of the normal adult mouse blood insulin. The addition of 0.1 to 1.0 microgram insulin/ml to Waymouth's medium was most beneficial to in vitro development. There was a statistically significant increase in protein synthesis, RNA content, glucose utilization, and heart rate, as well as a significant decrease in pericardial edema. DNA synthesis was unchanged or slightly decreased. The optimal amount of added insulin (0.05 microgram/ml) is much higher than the normal circulating levels in adult mice.

Animals↗
PubMed1978

Modern operative fluorocholangiography: utopia or overlooked entity?

A system of image amplification with television fluoroscopy and 100 X 100 mm cut film technique is presented for use in the operating room. Biliary surgery has benefited from this equipment as operative cholangiography has been improved and unnecessary extension of operating time avoided. Applications of the equipment for other procedures are discussed.

Biliary Tract Surgical Procedures↗
PubMed1975

Effect of gonadotropins on ovulation and ovarian histology in the immature Mongolian gerbil.

The present study is an analysis of the effects of superovulatory doses of gonadotropins on the rate and time of ovulation and ovarian histology in immature gerbils. Groups were treated with various combinations of pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (HCG). The maximum superovulatory response followed treatment with 10 IU PMSG and 20 IU HCG. High dosages of PMSG inhibited superovulation, as did some combinations involving the highest dose of HCG. Entrapment of ova within corpora lutes was common in groups receiving high doses of either gonadotropin. Luteal regression, appearing by day 3, occurred often in groups receiving high doses of HCG. A dose of 10 IU PMSG and 5 IU HCG resulted in both a near maximal superovulatory response and the least abnormal ovarian alteration.

Animals↗
PubMed1975

Direct selective myocardial revascularization by internal mammary artery-coronary vein anastomosis.

In this report, we shall describe our work with retrograde coronary perfusion, first in mongrel dogs and then in 6 patients. The left internal mammary artery (LIMA) is anastomosed to the left anterior descending coronary vein (LADV) to provide myocardial perfusion. This procedure may be of great value in the treatment of patients who are not suitable candidates for direct coronary bypass grafting, i.e., those who have diffuse atherosclerosis, with poor or no runoff of the left anterior descending coronary artery (LADA),but who have satisfactory left ventricular contraction.

Adult↗
PubMed1975

Reversal of pulmonary circulation.

The preliminary results and the technique of total reversal of the pulmonary circulation (RPC) are presented. Total RPC is technically feasible and not incompatible with life. It affords a new experimental model for in vivo study of pulmonary pathophysiology. The influence of this reversal on blood oxygenation, on pulmonary vascular resistance, and on established pulmonary hypertension, as well as its reaction to hypoxia and acidosis, needs further investigation. RPC may have clinical implications in essential pulmonary hypertension and congenital pulmonary vascular anomalies.

Angiography↗