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Biomedical subjects

T H Shepard

Publications and source records attributed to T H Shepard.

At least 109 records · Page 6Linked to original sources
PubMed1979

Combination chemotherapy for acute myelocytic leukemia during pregnancy: three case reports.

The cases of three patients with acute myelocytic leukemia presenting during the second trimester of pregnancy are summarized. All three patients were treated with combination chemotherapy. One patient, while in remission, underwent elective abortion of an apparently normal fetus. This patient is alive and free of disease 2 years after bone marrow transplantation. Each of the other two patients was spontaneously delivered of a premature infant. Transient bone marrow suppression occurred in one of these infants. Both children were small for their gestational age. One patient died 9 days after her infant was delivered and the other survived for 13 months.

Adult↗
PubMed1979

Embryonic and early fetal loss.

Embryonic and early fetal loss occurs in approximately one out of two pregnancies. Although this rate might appear unreasonably high, it is borne out by several types of studies and further confirmed by careful animal study. It now appears that karyotype deviation is common in early abortuses and probably underlies the high rate of gross abnormality seen in this group. In addition, environmental factors (radiation, smoking, anesthetics, and previous therapeutic abortion) may contribute to this wastage. Study and analysis of the abortus have allowed identification of a number of new embryonic and fetal syndromes. Careful description and classification combined with continued monitoring of abortuses shows promise both as an adjunct to reproductive counseling and as an important defense against teratogenic exposure. It is through this study that the etiology and ultimately the control of preventable pregnancy wastage will be understood and implemented.

Abnormalities, Multiple↗
PubMed1978

Maternal hyperthermia as a possible cause of anencephaly.

Mothers of anencephalic infants were asked about febrile illness and sauna bathing during their pregnancies. In 7 of 63 affected pregnancies (11%), a history of maternal hyperthermia near the presumed time of anterior neural-groove closure was given. 5 had fever with a maximum recorded temperature ranging from 38.9 to 40.0 degrees C, each case being secondary to a different type of illness. The other 2 had possible hyperthermia episodes as a consequence of sauna bathing, with no infectious agent involved. The frequencies of hyperthermia at the same period of gestation in two control groups were 0% and 0.1%. This excess frequency of maternal hyperthermia at the period of anterior neural-groove closure, and the differing natures of its causes, imply that hyperthermia itself may be an aetiological factor in anencephaly.

Adult↗
PubMed1977

Teratogenic effects of retinoic acid in pigtail monkeys (Macaca nemestrina). I. General features.

Daily oral administration of 10 mg/kg retinoic acid to pregnant Macaca nemestrina monkeys on days 20 to 44 resulted in a high frequency of craniofacial and musculoskeletal malformations. Craniofacial defects including cleft palate and anomalies of the prinna were common as were ectrodactyly, kyphosis, and muscular-joint contractures. Transposition of the great vessels of the heart occurred in one animal and polycystic kidney and associated urogenital anomalies in another. Shorter treatment periods with similar or higher dosages were not teratogenic and were less fetocidal. Although only relatively long treatment courses were teratogenic, the defects that resulted were morphologically similar to those induced with retinoic acid or other vitamin A compounds in other animal orders.

Abnormalities, Drug-Induced↗
PubMed1977

Teratogenicity of cytochalasin D in the mouse.

Cytochalasin D, a mold metabolite identified in food, was injected intraperitoneally in doses of 0.4 to 0.9 mg per kilogram on gestational days 7 through 11 and produced evidence of teratogenicity in two out of three strains of mice. Exencephaly, hypognathia and axial skeletal defects were found in strains C57BL/6J and BALB/c while no increase in defects was observed in the Swiss Webster strain. In all three strains, a significantly increased resorption rate was found. Oral doses of approximately 7.0 mg per kg on days 7 through 11 in the BALB/c produced exencephaly in the offspring. Autoclaved cytochalasin D retained its teratogenic potential.

Abnormalities, Drug-Induced↗
PubMed1976

Methods for detecting teratogenic agents in man.

At a multidiscipline international meeting sponsored by L'Institut de la Vie held at Guadeloupe in January 1974, current methods for detecting teratogenic agents were outlined and discussed. Recommendations of the participants of the conference were: recognize the limitations of the present defenses against teratogenic agents; educate the public and medical profession about the known human teratogenic agents; select for animal teratogenicity screening among new and existing agents by emphasizing substances to which the entire population will be exposed, agents to which pregnant women are exposed, viruses which are found to persist in the human fetus, and agents which have become suspect from clinical experience; recognize that nearly all compounds have a fetotoxic dose but that this does not imply teratogenicity; encourage the development of new, quick in vitro testing methods for detecting teratogenic agents; monitor for sudden increases in the frequency of specific malformations in newborn infants and in aborted fetuses; assure that expert multidiscipline committees are available to evaluate the threat when suspected teratogens are reported; improve teratology information storage and retrieval systems by record linkage of clinical data, linkage between computer systems, and universal identifier system for chemical compounds and congenical malformations; foster the exchange of data, particularly those held by the pharmaceutical industry.

Amniocentesis↗
PubMed1975

Potter syndrome. Nonrenal features induced by oligoamnios.

A fetus with normal kidneys and the nonrenal features of Potter syndrome is presented. The case is made that these features resulted from uterine compression caused by premature rupture of the gestational membranes and subsequent leakage of amniotic fluid.

Abnormalities, Multiple↗
PubMed1975

Studies of the development of congenital anomalies in rats. III. Effects of inhibition of mitochondrial energy systems on embryonic development.

Pregnant rats were treated with various inhibitors of mitochondrial oxidative energy metabolism and with lowered oxygen tension, and the embryo fetuses examined for the occurrence of congenital malformations and for changes in enzymatic activities. Treatment with all agents tested resulted in the production of skeletal anomalies. Sodium phenobarbital was the most teratogenic of the drugs tested and produced a high incidence of malformations which included cleft palate, tail anomalies, spinal retroflexion, domed head, and facial hypoplasia. Diphenylhydantoin produced a low incidence of syndactyly and oligodactyly. In addition to its effects on fetal growth and development chloramphenicol appeared to interfere with implantation. Tissue preparations from embryos exposed to sodium phenobarbital and chloramphenicol showed markedly lowered levels of DPNH oxidase activity. Cytochrome oxidase activity was also markedly lowered in the preparations from chloramphenicol-exposed embryos. Enzyme activities in preparations from embryos exposed to malonate and diphenylhydantoin appeared unaffected, although the drugs are strong inhibitors of electron transport in vitro; the lack of apparent effect may be due to the fact that both drugs do not bind to the enzyme preparations and were diluted 100- to 200-fold during preparation and assay of the tissue homogenates.

Abnormalities, Drug-Induced↗
PubMed1975

Fetal renal malformation following treatment of Hodgkin's disease during pregnancy.

A case of human fetal renal maldevelopment following the administration of nitrogen mustard, vincristine, procarbazine, and prednisone in early pregnancy for therapy of Hodgkin's disease is reported. While these agents have been shown to be teratogenic in animal experiments, adverse fetal effects following their use during early human pregnancy have not been described. In spite of this previous experience, it has generally been recommended that these agents be withheld during the first trimester of pregnancy because of their presumed teratogenic potential. This case would seem to reinforce this recommendation.

Abnormalities, Drug-Induced↗