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Urokinase type plasminogen activator (uPA) and its inhibitors, plasminogen activator inhibitor type I (PAI-1) and type II (PAI-2), are supposed to be involved in the expression of the invasive and metastatic phenotype of cancer cells. However, clinical investigations on the prognostic significance of their levels in tumor tissue are difficult to realize because of the absence of a convenient method of measurement of these parameters. The aim of the present investigation was to set up a method allowing the measurement of these enzymes and of sex steroid receptor status in appropriate subcellular fraction(s) in conditions easily reproducible in routine. We found that a tissue homogenate prepared according to the method recommended [5] for current measurement of sex steroid receptors is appropriate for further distinct preparations. One aliquot is used for cytosol preparation; another can be treated by 2% Triton X-100 (vol/vol) and provide an extract containing the totality of uPA and PAI-1. The advantage of this procedure is that appropriate subcellular fractions can be derived from a unique homogenization step. Total uPA and PAI-1 are measured in a Triton extract with good performance as compared to previous investigations [4]. PAI-2 is measured in the same cytosol fraction used for sex steroid receptors and other parameters. Because of its simplicity and its high reliability, this method could be a useful tool in the investigation of uPA family proteases and analysis of their prognostic significance in early breast tumors.

Different methods are available for cobalamin determination in serum. Microbiological and radio ligand binding assays are the most commonly used. Kits involving non-isotopic competitive-binding assay have been recently commercialized. In the present work, cobalamins were determined in 146 patient sera, using four methods: a microbiological method, two no boil radio ligand binding assay kits (Magic B12 FOL (NB) from Ciba-Corning and SimulTRAC SNB No Boil from Becton Dickinson) and a non-isotopic kit with acridinium ester labelled cobalamin (Magic Lite from Ciba-Corning). Median (range) cobalamin concentrations in pmol l-1 were 317 (15-1291) using the microbiological method, 355 (25-3469) using the Magic Lite kit, 355 (35-2312) using the Magic B12 FOL (NB) kit and 380 (37-2021) using the SimulTRAC SNB No Boil kit. The ANOVA test indicated that differences between methods were statistically significant (p < 0.01). Competitive-binding methods gave higher results than the microbiological method. Although correlation coefficients were not excellent (0.88 < r < 0.96), the results obtained with the different methods were generally similar and confirmed that competitive methods are useful for detecting low serum concentration of vitamin B12.

Ruthenium (III) tris acetylacetonate is an efficient catalyst for the isomerization of O-deuterated alkylvinyl carbinols allowing thus a facile route to the title compounds.

Summary To detect a foreign collagen in a tissue on a substantially idemtied protein, a radio-tracer technique appeared ideal. The method is only valuable if the introduction of the tram element into the micro molecule does not modify its properties. The first collagen used was tagged by the introduction of C1* into the peptide chain from marked proline by biosynthesis. A 0.3% concentration in sorbic acid solution was applied to the back of the animal and the penetration followed by measuring the activity of tissue sections. No radioactivity was found in the interior of the deinnir after periods of 15, 30,90 and 120 min after application. The method of biosynthetic marking was abandoned as the activity of the protein was considered to be insufficient. The technique of the incorporation of 1(125) in the tyrosine was used to obtain a greater specific activity without modifying the active principle. This chemical treatment resulted from the oxidation of tagged iodide in the presence of collagen. The protein was purified by chromatography and successive dialyses and diluted in unlabelled collagen for subsequent manipulation. Skin applications were made in sorbic acid solution at 0.3% and at 10% in a cosmetic cream. Skin penetration forthe same periods as previously were followed by the same sectionning technique. The penetration reached a maximum at the end of 15 min and was greater for the cream than for the solution. Metabolic studies showed that 15 days after application the residual radioactivity was present mainly in the lymphatic glands and in the skin. Treated dcin showed more activity than untreated areas. At the end of 10 days the excretion of radioactivity had dropped to very low levels. Chromatography on molecular sieve of the collagen extracted from the deeper layers on the skin indicated that the largest part of the radio-activity originated in peptide chains.

Evidence is presented for the reversible formation of metal-alkyne complex in the pyrolysis of eta/sup 5/-cyclopentadienyl-eta/sup 4/-cyclobutadiene-cobalt complexes. (DLC)

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