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Biomedical subjects

J D Harder

Publications and source records attributed to J D Harder.

22 records · Page 2Linked to original sources
PubMed1981

Estradiol and progesterone profiles indicate a lack of endocrine recognition of pregnancy in the opossum.

Concentrations of estradiol and progesterone in blood collected during the 12.5-day gestation period of the Virginia opossum were not significantly different from those during equivalent days of the estrous cycle. Progesterone was correlated with an index of corpora luteral mass. Ratio of estradiol to progesterone were highest 3 to 4 days before estrus and on the day of parturition.

Animals↗
PubMed1981

Uterine histology and reproductive cycles in pregnant and non-pregnant opossums, Didelphis virginiana.

Uteri (N = 18) were collected on Days 3, 7, and 11 of the oestrous cycle or gestation. Reproductive cycles were monitored by vaginal cytology in captive opossums. There was no difference in length of cycles between reproductive states (29.2 +/- 1.0 (s.e.m.) days). All uteri on Day 3 or Day 7 were similar in total volume, endometrial width, and glandular abundance. However, on Day 11 endometrial widths were significantly less in pregnant animals and stroma appeared diffuse and flocculent in the non-pregnant uteri. The chorio-vitelline membrane induced no change in the size, conformation, or structure of the uterine epithelium. In some areas, trophoblast cells or their cellular fragments were attached to the epithelium, indicating that the embryonic-maternal relationship might entail adhesion or interdigitation as well as apposition. A mucopolysaccharide layer also characterized this interface of heterologous tissues.

Animals↗