Bioactive to immunoreactive ratio of circulating human chorionic gonadotropin as possible evaluation for the prognosis of threatened abortion.

Objective: In an effort to evaluate the prognosis of threatened abortion, we established the ratio of serum human chorionic gonadotropin (hCG), as measured by bioassay or radioimmunoassay techniques, of samples from patients with threatened abortion or normal pregnancy.

Study Design: Peripheral blood samples from patients in their first trimester of pregnancy with threatened abortion (n=24), or normal pregnancy (n=12), were assayed for progesterone (RIA), and for immunoactive (DELFIA) and bioactive (mouse Leydig cell testosterone production assay) hCG.

Results: Serum progesterone was not statistically different between the threatened-continuing and the threatened-miscarried groups.

Bioactivity of serum hCG in preeclampsia.

Objective: To compare hCG levels, obtained by biologic and immunologic means, in women with normal pregnancies and women with preeclampsia.

Methods: Peripheral blood samples from women in the third trimester with preeclampsia (n = 30) or normal pregnancies (n = 30) were assayed for immunoactive and bioactive hCG (mouse Leydig cell testosterone production assay).

Results: Serum bioactive hCG levels tended to be lower than normal, and immunoactive hCG levels tended to be higher in women with preeclampsia, but the differences were not statistically significant.

Thiamine pyrophosphate (TPP) negatively regulates transcription of some thi genes of Salmonella typhimurium.

In Salmonella typhimurium, thiamine is a required nutrient that is synthesized de novo. Labeling studies have demonstrated probable precursors for both the 4-amino-5-hydroxymethyl-2-methylpyrimidine pyrophosphate moiety and the 4-methyl-5-(beta-hydroxyethyl) thiazole monophosphate moiety. The isolation of thiamine auxotrophs with mutations in at least five different genetic loci is reported.

Ontogeny of the epidermal growth factor receptor during development of the fetal bovine mesonephros and associated organs of the urogenital tract.

A primary cell culture system was developed to study the epidermal growth factor (EGF) receptor in the fetal bovine mesonephros and its urogenital derivatives. Radioreceptor assays demonstrated EGF binding as early as Day 37 in mesonephric cells and in cells derived from the fetal reproductive ducts, gonads, and metanephros--all mesonephric derivatives. Immunocytochemical studies revealed that EGF receptors were localized in the ductal and tubular epithelium of these urogenital organs.

Evaluation of the pituitary-thyroidal axis in newborns undergoing exchange transfusion.

To evaluate whether the hypothyroxinaemia, previously noted in hyperbilirubinaemic newborns immediately after exchange transfusion for Rh or AB0 incompatibility, was due to impairment in the secretion of thyroid stimulating hormone (TSH) by the pituitary, we studied the thyroid hormone response to thyrotropin releasing hormone (TRH) and compared this response to that seen in a control population of healthy neonates. All infants studied responded with a brisk TSH increase; 30 min after TRH injection the mean TSH concentration of the hyperbilirubinaemic patients was 37 microU/ml, ten times their basal level, which was not different from the value noted in the control population. No significant change in total thyroxine (T4), 3,5,3' triiodothyronine (T3), free thyroxine (FT4) or 3,3',5' triiodothyronine (rT3), (FT4) or (rT3) was noted after TRH administration in either group of neonates.