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Biomedical subjects

V H Ferm

Publications and source records attributed to V H Ferm.

At least 37 records · Page 2Linked to original sources
PubMed1981

Teratogenic effects of aliphatic nitriles.

Intraperitoneal injection of acrylonitrile at 1.51-2.26 mmole/kg (80-120 mg/kg) or propionitrile at 0.54-1.51 mmole/kg (30-83 mg/kg) on the morning of Day 8 of gestation in the hamster induced exencephaly, encephalocoeles, and rib fusions and bifurcations in the offspring. These doses of the aliphatic nitriles also resulted in obvious toxicity to the dams. Multiple intraperitoneal injections of sodium thiosulfate at 4.03 mmole/kg (1 gm/kg) protected both dams and embryos against toxicity. When the larger doses of either acrylonitrile or propionitrile were given in the presence of sodium thiosulfate, teratogenic effects were observed in the absence of overt signs of maternal poisoning. A survey of the literature describes many studies which demonstrate that acrylonitrile and propionitrile are converted in vivo to toxicologically significant concentrations of cyanide and that sodium thiosulfate, an established cyanide antagonist, can provide protective actions against poisoning by either acrylonitrile or propionitrile. The observations suggest that the teratogenic effects of both acrylonitrile and propionitrile are related to the metabolic release of cyanide.

Abnormalities, Drug-Induced↗
PubMed1981

Morphogenesis of axial skeletal (dysraphic) disorders induced by aliphatic nitriles.

The previous study (Willhite et al., '81) linked the administration of acrylonitrile or propionitrile in the pregnant hamster to the production of severe axial skeletal (dysraphic) malformations in the hamster fetus. The present investigation dealt with histological study of both early embryos and term fetuses challenged with a teratogenic dose of either of these nitriles. Inspection of hamster embryos 10 hours after the teratogenic stimulus revealed mesodermal changes including a reduced number of cells, shrinkage of the cell cytoplasm, and enlarged extracellular spaces. In addition, a reduced number of mitotic figures and focal necrobiosis were noted. The affected embryos were smaller and were delayed in their development as compared to controls. Analysis of the fourteen-day-old hamster fetuses revealed the basichondrocranium in both cranioschisis occulta with encephalocoele and cranioschisis aperta with exencephyaly to be shorter than control and lordotic to the vertebral axis. These alterations were more accentuated in cranioschisis aperta than in cranioschisis occulta. The ultimate skeletal malformations may be the reflection of a primary paraxial mesodermal insufficiency.

Abnormalities, Drug-Induced↗
PubMed1979

Teratogenic interaction of hyperthermia and vitamin A.

Exposure of pregnant hamsters to 60--75 min of hyperthermia on the 8th day of gestation causes malformations in some of the fetuses recovered near term. The feeding of large doses of vitamin A to pregnant hamsters on the 8th day of gestation causes many of the same types of malformations. When pregnant hamsters are treated with the minimal teratogenic hyperthermic stress plus the minimal teratogenic dose of vitamin A there is a clear augmentation of the teratogenic effect on the embryo. The implication that maternal hyperthermia may be an important synergistic factor for a variety of potentially teratogenic influences during pregnancy is discussed.

Abnormalities, Drug-Induced↗
PubMed1978

Teratogenic effects of ribavirin on hamster and rat embryos.

Ribavirin, a synthetic nucleoside with marked antiviral activity, induced developmental malformations when administered to pregnant hamsters by oral, intraperitoneal or intravenous routes. Abnormalities of the limbs, eyes and brain were the most common defects found in the hamster. Higher doses (about 10 x) were required to induce anomalies in rat embryos and the malformations were generally restricted to the head region. In both rats and hamsters oral administration of the drug seemed to be more teratogenic than administration by other routes suggesting that metabolism of ribavirin in the maternal gastro-intestinal tract and/or liver may change it into its active form.

Abnormalities, Drug-Induced↗
PubMed1978

Cranio-dirachischisis totalis in cephalothoracopagus twins.

A set of conjoined 13-day-old male hamster twins is described. The twins were joined at the head and thorax. The brain was exencephalic and the neural plate was completely open throughout its length. The notochord was duplicated throughout its entire length. Partial twinning of the neural plate as indicated by histologic reconstruction is suggested with fusion or non-separation of the neural plates in the medial alar wing area. There was complete separation of the neural plates together with duplication of the lower extremities and tails in the caudal region of this specimen.

Abnormalities, Drug-Induced↗
PubMed1977

Congenital anomalies induced in hamster embryos with ribavirin.

Ribavirin, when given to pregnant hamsters in relatively small single doses, induces congenital anomalies of limbs, ribs, eyes, and central nervous system, as well as fetal deaths. On the basis of these findings, caution should be used in giving ribavrin to women of child-bearing age.

Abnormalities, Drug-Induced↗
PubMed1977

Arsenic as a teratogenic agent.

Sodium arsenate induces developmental malformations in a variety of experimental animals. In the golden hamster, the intravenous (or intraperitoneal) administration of 20 mg/kg of sodium arsenate during day 8 to 9 of gestation induces a rather specific spectrum of congenital malformations. This period corresponds to the period of very rapid differentiation and major organogenesis in this animal. The spectrum of defects produced by arsenate in the hamster includes exencephaly, encephaloceles, skeletal defects, and malformations of the genito-urinary system. This teratogenic effect can be significantly reduced by the simultaneous administration of selenium. Recent studies in this laboratory have demonstrated the permeability of the placenta to 74As during the early critical stages of embryogenesis and the distribution of this isotope in maternal, placental and embryonic tissues. We have also recently demonstrated the marked potentiation of the teratogenic effect of sodium arsenate by subjecting the mothers to short periods of hyperthermia immediately following the administration of subteratogenic or minimal teratogenic levels of arsenate.

Abnormalities, Drug-Induced↗
PubMed1976

Exencephaly in fetal hamsters following exposure to hyperthermia.

Exposure of pregnant hamsters on gestation day 8 to 40 or 41 degrees C for one hour caused an increased rate of resorption and a high frequency of exencephaly and encephalocele. Longer exposures often killed pregnant females. Hamsters that had fetuses with abnormalities usually experienced body temperature elevations of 3-4 degrees C above normal (37 degrees C).

Animals↗