The effectiveness of 3 compounds, procarbazine, mitomycin C and cyclophosphamide as inducers of sister-chromatid exchanges (SCEs) in granulocyte-macrophage progenitor cells, in foetal liver and bone marrow from pregnant mice at day 17 of gestation were determined. Cyclophosphamide and procarbazine induced similar SCE frequencies in maternal and foetal cells. Mitomycin C was slightly less effective in foetal liver than in maternal bone marrow. In contrast to the results of SCE induction, cyclophosphamide produced more micronucleated polychromatic erythrocytes in foetal liver than in bone marrow. The SCE results for mitomycin C and procarbazine are compared with results obtained previously for micronuclei induction in 15-day pregnant animals.

Animals↗

PubMed1984

Bretylium in hypothermia-induced ventricular fibrillation in dogs.

We undertook a study to determine the ability of intravenous bretylium to cause "chemical defibrillation" or facilitate electrical defibrillation of hypothermia-induced ventricular fibrillation in the dog. Two groups of ten dogs were cooled to 22 C and placed into ventricular fibrillation. Following initiation of cardiopulmonary resuscitation, bretylium 15 mg/kg or normal saline was administered and the dogs were defibrillated according to a standard protocol. Both groups were equivalent in mean arterial pressure and arterial blood gases throughout the investigation. Seven dogs in each group were converted from ventricular fibrillation to an organized cardiac rhythm (P greater than .05). Despite the possible value of prophylactic bretylium in the setting of hypothermia, its use as active treatment for hypothermia-induced ventricular fibrillation in dogs does not seem to be beneficial.

Animals↗

PubMed1983

Short-term tests for transplacentally active carcinogens. Induction of sister-chromatid exchanges in foetal brain, lung and blood-forming cells by procarbazine and cyclophosphamide.

The induction of sister-chromatid exchanges (SCEs) by cyclophosphamide (CP) and procarbazine (PC) in mouse granulocyte-macrophage precursor cells (GM cells) and erythroblasts from foetal liver, and cells from foetal brain and foetal lung has been measured. Agents were administered in vivo, and cells explanted into BrdUrd-containing medium for 2 cell cycles in vitro (using specific growth-promoting substances where necessary) to determine SCE frequency. Tissue and cell-type differences in responses were observed, and it is concluded that the in vivo/in vitro transplacental SCE technique is a useful indicator of genotoxic effects of agents which are potential transplacental carcinogens.

Animals↗

PubMed1978

The influence of alachlor, trifluralin, and diazinon on the development of endogenous mycorrhizae in soybeans.

Preplant incorporated treatments of 2 and 4 kg/ha of trifluralin and diazinon had no significant effect on growth, P accumulation or root colonization by mycorrhizal fungi in soybeans planted in an Andover clay loam. At 4 kg/ha, alachlor and trifluralin inhibited root development of 25 day-old plants. The 4 kg/ha alachlor treatment reduced shoot weight of 25 day old plants significantly and suppressed mycorrhizal development of 25 to 60 day old plants. At currently used commercial rates neither alachlor, trifluralin, nor diazinon affected mycorrhizal development under the conditions of the experiment.

Acetanilides↗

PubMed1974