Simple direct radioimmunoassay of the F prostaglandins

A simplified and accurate method of determining the F prostaglandins in 0.1 ml of serum without previous extraction is described. The procedure involves addition of anti-prostaglandin F_2α to serum followed by tritiated prostaglandin, equilibration for 4 hours, removal of unbound prostaglandin with dextran-coated charcoal and subsequent liquid scintillation counting of the supernatant. The mean ± S.D. concentration of prostaglandin F_2α in the serum of 15 healthy men was 90 ± 33 pg/ml and in 20 women 108 ± 43 pg/ml.     

Variables associated with radioimmunoassay of prostaglandins in plasma

This study examined a number of variables which influence radioimmunoassay measurements of prostaglandins in plasma. Comparative assays in specimens obtained from normal subjects and processed by different methods demonstrated that prostaglandin measurements were uniformly lower when blood was anticoagulated with EDTA, aspirin or indomethacin was added to inhibit further synthesis of prostaglandins , samples were centrifuged at 4°C at speeds which removed platelets from the sample, and assays were performed when plasma was thawed for the first time. Examination of assay results also revealed that the presence of unextracted plasma enhanced the binding of labeled ligands to antisera (%B_o) but thereafter, the displacement of ligand by increasing quantities of the reference prostaglandin paralleled the results in buffer throughout the range of the assay. In subsequent studies therefore the %B_o for plasma assays was adjusted on the basis of ligand binding in the presence of comparable volumes of pooled plasma from aspirin-treated subjects. Results of 7 prostaglandin assays in plasma and serum of normal subjects are reported.     

Trypsin inhibitors in human urine (author's transl)

By using ammonium sulfate, Arg-Sepharose and gel filtration, an urinary trypsin inhibitor (UTI) with molecular weight of 67,000 (UTI7) was isolated from normal human urine. The yield of UTI7 was about 3,200 U per liter of urine. When urine was acidified, an uropepsin-like substance was activated which caused molecular weight change of UTI7. New UTIs had molecular weight of 45,000 and 22,000 (UTI4-5 and UTI-2-2), respectively. These inhibitors showed a strong effect on trypsin, alpha--chymotrypsin and lesser extent on plasmin and elastase, but had no effect on esterolytic activity on thrombin and the first components of complement Cls an Clr.     

Constitutional stereotyped gap in human chromosomes (author's transl)

The stereotyped break with gap of a chromosomal variant is rarely observed. This anomaly is transmitted according to autosomal dominant rule. The distal part of the broken chromosome may either be still bound to the sister chromatid through mitotic non-disjunction, forming a triradial figure, or take a moniliform and pulverized appearance, evoking premature chromosome condensation.     

A radioimmunoassay for the initial metabolites of the F prostaglandins

Antibodies to the F metabolite 9α, 11α-dihydro-15-keto-prostanoic acid (I), produced in the rabbit, do not cross react with any of the primary PGs. There is a 50% cross reaction with the metabolite 9α, 11α-dihydroxy-15-keto-prost-5-enoic acid (III), and a 23% cross reaction with 9α,11α,15-trihydroxy prostanoic acid (F₀α). No cross reactivity resulted with this antiserum when tested against 9α,11α,15-trihydroxy-5-enoic acid (VII) or with 9α,11α-dihydroxy-15-ketoprost-5,13-dienoic acid (VIII). Utilizing this antibody in a radioimmunoassay, some preliminary data are presented on levels of these F metabolites (I and III) for human adult male samples of plasma, urine and seminal plasma.