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Biomedical subjects

L C Ulberg

Publications and source records attributed to L C Ulberg.

At least 19 recordsLinked to original sources
PubMed1980

Ovulation rate, embryo survival and ovarian sensitivity to gonadotrophins in mice selected for litter size and body weight.

Single trait selection of mice for either large body size or large litter size resulted in an increased ovulation rate because of possible enhanced ovarian sensitivity to gonadotrophins. There was no difference in pre-implantation embryonic survival in either of the selected lines when compared to control mice. Selection for body weight did not alter post-implantation embryo survival, but fewer fetuses were lost after implantation in the litter size line compared to the control line. Index selection for large body size and small litter size did not change ovulation rate but increased pre- and post-implantation embryonic mortality. Selection for small body size and large litter size increased ovulation rate and decreased early embryonic death.

Animals↗
PubMed1976

Circulating placental lactogen levels in dairy and beef cattle.

Levels of bovine placental lactogen (bPL) have been measured in the serum of dairy and beef cattle and in the milk and amniotic fluid of pregnant animals with a highly specific radioimmunoassay. In both dairy and beef cows, serum bPL levels remain low (less than 50 ng/ml) during the first two trimesters and then rise rapidly between 160 and 200 days of gestation to a plateau. The bPL levels do not decline prior to parturition. During the last trimester, serum levels in dairy cows, 1103+/-342 ng/ml, are significantly higher than those in beef cattle, 650+/-37 ng/ml (P less than 0.01); furthermore, dairy cows having a high milk production also tend to have high bPL levels. Serum levels are almost twice as high in twin pregnancies and are not correlated with fetal sex or birth weight. bPL levels in milk and amniotic fluid from dairy cattle during the last trimester are approximately 86% and 25% of the serum values, respectively, suggesting that bPL enters these fluids by passive diffusion.

Amniotic Fluid↗
PubMed1975

Reversibility of clip sterilization.

A spring clip designed to be applied to the fallopian tube for sterilization without electrocoagulation was applied to 10 pigs. After documenting the prevention of pregnancy for 3 months, the clips were removed and successful reanastomosis was performed on eight pigs. Six of these pigs became pregnant within 2 months of the reanastomosis. This paper describes the technique of the reanastomosis and documents the potential reversibility of spring clip sterilization.

Animals↗