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Biomedical subjects

K Benirschke

Publications and source records attributed to K Benirschke.

At least 127 records · Page 7Linked to original sources
PubMed1982

Fetal-maternal gradients of steroid hormones in the nine-banded armadillo (Dasypus novemcinctus).

Gonadal and adrenal steroid hormone levels in plasma were measured in pregnant, non-pregnant and fetal armadillos. Progesterone demonstrated the largest placental gradient with levels 6 to 10-fold higher in the fetus. Testosterone levels were higher in male and lower in female fetuses, when compared to the respective maternal serum values. Dehydroepiandrosterone, and cortisol were consistently high in maternal as compared to matched fetal serum samples whereas the reverse was true for androstenedione. Tissue incubations with labelled pregnenolone indicated the major source of progesterone production to be the fetal adrenal whereas the fetal testes demonstrated a major conversion product consistent with dehydroepiandrosterone.

Animal Population Groups↗
PubMed1981

Congenital anomalies in Lemur variegatus.

In a colony of black and white ruffed lemurs, Lemur (Varecia) variegatus subsp., similar congenital anomalies were found in successive years. Four malformed infants had skull defects, scoliosis, kinked tails, internal anomalies as well as reduced birth weights. The derived from one male and two females whose phenotypes are normal except for the kinked tail of the male. The possible causes including modes of inheritance are considered.

Abnormalities, Multiple↗
PubMed1981

Premature labor. I. Prostaglandin precursors in human placental membranes.

Amnion and chorion from premature and term placentas after both spontaneous labor and elective cesarean section were assayed for phospholipids and fatty acid composition by 2-dimensional thin-layer chromatography and gas-liquid chromatography. In preterm placental phospholipids, phosphorus concentrations were higher in amnion than in chorion, whereas at term the membranes were similar owing to an increase in phospholipid concentration in the chorion late in gestation. PHosphatidylcholine (PC) accounted for 47% of the total phospholipid phosphorus, followed by sphingomyelin at 20%, phosphatidylethanolamine (PE) at 15%, phosphatidylserine (PS) at 12%, and phosphatidylinositol (PI) at 5%. These percentages were similar for amnion and chorion and they did not change during gestation. The percentage of arachidonic acid (AA) was higher in PS (40 to 65%) than in PE (30 to 53%) and PC (10 to 13%). The percentage of AA was significantly higher in PC, PE, and PS from the amnion in premature pregnancies than in those of the premature chorion. At term, these amnionic and chorionic phospholipids had similar concentrations of AA owing to a significant increase in AA in the chorion late in gestation. Amnionic PE from term and preterm elective cesarean section had a significantly higher percentage of AA than that from preterm and term labor. These data suggest that AA is consumed during labor and that amnionic phospholipids, particularly PE, may be its principal source. The amnion seems to be more important for the storage of AA than the chorion, particularly in preterm pregnancies in which the concentrations of phospholipids and the percentages of AA in PC, PE, and PS were significantly higher than in the chorion.

Amnion↗
PubMed1980

Hypertrophy of the placenta and sacrococcygeal teratoma. Report of two cases.

This report describes two pregnancies complicated by hydramnios, fetal death and sacrococcygeal teratoma in the second trimester. In both cases the placenta was remarkably enlarged. It is postulated that the tumors behaved in the manner of A-V fistulas and produced forward failure in the fetus similar to what is occasionally seen with large chorangiomas.

Female↗
PubMed1980

The unusual karyotype of the lesser kudu, Tragelaphus imberbis.

The chromosome set of the lesser kudu, Tragelaphus imberbis, consists of 38 elements in both sexes. In contrast to most other members of the bovid subfamily Tragelaphinae, both the X and the Y chromosomes are compound, having fused with identical autosomes from ancestors presumed to have higher chromosome numbers. From a comparison of the unusual sex chromosomal rearrangements that have occurred in this family, a hypothetical lineage has been derived. This family tree and the details of various banding studies in the lesser kudu are described.

Animals↗
PubMed1980

Reduced gonadotropins in athymic mice: prevention by thymic transplantation.

The reduction in pituitary concentrations of gonadotropins observed in 20-day old congenitally athymic nude mice in comparison to their normal heterozygous littermates was completely prevented in females and partially prevented in males by thymic transplantation on the first day of life. Those athymic mice receiving transplants but in which no thymic tissue could be found at sacrifice had reduced pituitary gonadotropin concentrations equivalent to sham-operated athymic animals. From these data we infer that the reduced concentrations of gonadotropins seen in the athymic animals are causally related to the absence of the thymus and suggest that the thymus, directly or indirectly, is necessary for development of normal function of the hypothalamic-pituitary-gonadal axis in mice.

Animals↗
PubMed1980

H-Y antigen in a fertile XY female horse.

The presence of significantly reduced levels of H-Y antigen in the blood of an XY mare is consistent with the view that H-Y genes comprise a system of testis determinants. Loss or suppression of a critical portion of H-Y genes and subthreshold expression of H-Y antigen could account for a failure of testicular differentiation, thereby allowing a measure of ovarian development in an XY embryo.

Animals↗
PubMed1980

Gorilla diseases and causes of death.

The causes of 48 gorilla deaths were investigated and normal weights for organs ascertained. Half of the gorilla deaths in zoos occurred before maturity at around 8 years of age. Eight of the 48 died in the perinatal period from rejection, stillbirth or abortion. The majority of gorillas succumb to various types of enterocolitis. The most common aetiological agents are Shigella, Salmonella, Balantidia and a variety of parasites, principally Strongyloides. A variety of preventable virus infections and fungal infections are important diseases that must be avoided in the captive maintenance of gorillas. Dental problems emerge as a recently recognized threat for gorillas, as does mycoplasma infection with arthritis.

Animal Husbandry↗
PubMed1980

Leiomyomatosis peritonealis disseminata with endometrium.

A case of leiomyomatosis peritonealis disseminata (LPD) is presented with the unique finding of occasional endometrial glands and stroma within smooth muscle nodules. The possible origins of this tissue are discussed in relation to the histogenesis and prognosis of LPD.

Adult↗
PubMed1980

Ovarian and adrenal steroidogenesis in a virilized patient with gonadotropin-resistant ovaries and hilus cell hyperplasia.

A 26-year-old woman with secondary amenorrhea, temporal balding, and clitoromegaly was found to have both the gonadotropin-resistant ovary syndrome and hilus cell hyperplasia. Simultaneous sampling of peripheral and ovarian venous blood revealed excess ovarian testosterone secretion to be the probable cause of the patient's virilism. The marked response of the ovary to stimulation by luteinizing hormone (LH) coupled with the lack of ovarian follicular development suggested that an isolated resistance of the ovarian follicle to follicle-stimulating hormone (FSH) was present in this patient. The administration of a daily pharmacologic dose of dexamethasone for 14 days was followed by the patient's first menstrual period in 13 years, raising the possibility that autoimmunity may have been involved in this patient's ovarian resistance to FSH stimulation.

Adult↗