[In vitro enzyme inhibitory and in vivo cardioprotective activities of hibiscus (Hibiscus sabdariffa L.)]. / Activités inhibitrices enzymatiques in vitro et angioprotectrice in vivo d'extraits de karkadé (Hibiscus sabdariffa L.).

A crude hydroalcoholic extract from Hibiscus sabdariffa L. calyces showed in vitro an appreciable enzyme-inhibiting activity towards the Angiotensin I Converting Enzyme (ACE), attributable to flavones, but weak inhibiting activities towards elastase, trypsin and alpha-chymotrypsin. The angioprotective activity in vivo, also important, was due to flavones and anthocyanins.

[Synthesis and pharmacologic study of several spirohydantoins: relation to conformation]. / Synthèse et approche pharmacologique de quelques spirohydantoines: relation avec la conformation.

Using two routes starting from cyclanones, it has been possible to prepare two series of spirohydantoins substituted or not on the hydantoin nucleus nitrogen. These compounds exhibited low toxicity on pig lens aldose reductase (except for two compounds). A discussion is given on the steric and geometric requirements for effective enzyme inhibiting activity.

[Flavonoids extracted from Ribes nigrum L. and Alchemilla vulgaris L.: 1. In vitro inhibitory activities on elastase, trypsin and chymotrypsin. 2. Angioprotective activities compared in vivo]. / Flavonoïdes extraits de Ribes nigrum L. et d'Alchemilla vulgaris L.: 1. Activités inhibitrices vis-à-vis de l'élastase, de la trypsine et de l'alpha-chymotrypsine in vitro. 2. Activités angioprotectrices comparées in vivo.

In vitro experiments were conducted on the inhibitory properties of extracts from Ribes nigrum L. and Alchemilla vulgaris L. (fractions A1 + A2, A1, A2) on activity of the proteolytic enzymes elastase, trypsin and alpha-chymotrypsin. Extracts from Ribes Nigrum L. and Alchemilla Vulgaris L. (Fraction A1) inhibited 50% of the activity of porcine pancreas elastase at concentrations of 0.56 mg/ml and 0.16 mg/ml, respectively, against a synthetic substrate. Inhibition was less effective on activity of trypsin and alpha-chymotrypsin. Marked in vivo angioprotective properties were shown by the compounds studied, except Fraction A2 of Alchemilla vulgaris L. which had no significant activity. The results suggest a possible role by these inhibitors in the protection of conjunctive and elastic tissues adversely affected by proteolytic enzymes. An additional advantage is their lack of toxicity.

[Comparative study of three presentations for research on HBs antigen by the immunoenzyme technique]. / Etude comparative de trois présentations de recherche de l'antigène HBs par technique immunoenzymatique.

The authors present the results of a study comparing the detection of HbSAg by enzyme immunoassay using the following three different commercial kits and their corresponding apparatus: Auszyme II, Quantum II from Abbott; Enzygnost micro Elisa, Elisa Processor from Behring; Hepanostika, washer and reader micro Elisa system from Organon. The purpose of the study is to determine the sensitivity and specificity of the reaction and the extent of automation of this method. The sensitivity and specificity of the 3 kits are compared with those of a reference technique, the radioimmunoassay Ausria II, Abbott. The sensitivity of Auszyme II is equivalent to that of Ausria II and is approximately 0.2 mg/ml. The other two kits are somewhat less sensitive. The proportion of false negative is less than 1%, but with all 3 kits it is necessary to verify a negative result. The results of this study confirm the high level of sensitivity and specificity of the enzyme immunoassay for the detection of HbSAg in the serum or plasma of blood donors. This technique therefore offers an alternate method of HbSAg detection to laboratories which cannot or prefer not to use a radioimmunoassay.

[Effects of optotoxic substances on several glycolytic enzyme activities in the retina of the pig (author's transl)]. / Effets de substances optotoxiques sur quelques activités enzymatiques glycolytiques au niveau de la rétine chez le porc.

1. The authors report the results obtained after the action of certain optotoxic substances on several enzyme activities in the retina of the pig. 2. This in vitro study involved enzyme interferences of the following optotoxic agents : ethionamide, d-penicillamine, ethylene diaminotetra-acetic acid (EDTA), disodium and dicobalt salts. The enzyme activities studied involved glycolysis, the enzymes selected being as follows: glucose phosphate isomerase (GPI, E.C. 5.3.1.9), fructose-1,6-diphosphate aldolase (F1-6diPA, E.C. 4.1.2.13), lactate dehydrogenase (LDH, E.C. 1.1.1.27). 3. Following the action of the effectors studied, a marked decrease in the enzyme activities examined was found in the retina. This decrease, of varying rapidity and regularity, went as far in some cases as total inhibition; there was disturbance of glycolysis. 4. These results indicate the existence of interactions with a complex mechanism. It may be noted that all of the effectors studied were chelating agents of divalent metals and the changes which they induced in the enzyme activities examined may be explained by interference of the chelates formed with metal cations, such as Zn++, co-factors or effectors of these glycolysis enzymes (with the exception of GPI). These stable chelates are formed by virtue of the primary amine--NH2, thiol--SH, thionyl-[Formula: see text] groups, i.e. groups belonging to molecules essential to cell metabolism.

[Action of pharmacological effectors on hematocrit and lactate dehydrogenase activity changes in experimental ischemic shock]. / Action d'effecteurs pharmacologiques sur les variations de l'hématocrite et de l'activité lactate déshydrogénasique au cours du choc ischémique expérimental

The experimental ischemic shock induced by removing tourniquets in rats, were studied. Durin 164 hours, the variations of the values of hematocrit and of muscle and plasma dehydrogenase lactate activity were followed up; the modifications of these variations after pharmacological high doses of dexamethasone phosphate, hydrocortisone hemisuccinate and aprotinine administered intravenously, were evaluated. The best action was noted after dexamethasone phosphate treatment.

[Variations of various enzymatic activities of the Krebs cycle (malate dehydrogenase, isocitrate dehydrogenase, succinate dehydrogenase) during experimental ischemic shock in the rat. Influence of adenosine 5' triphosphoric acid]. / Variations de quelques activités enzymatiques du cycle de Krebs (malate déshydrogénase, isocitrate déshydrogénase, succinate déshydrogénase) au cours du choc ischémique expérimental chez le rat. Influence de l'acide adénosine-5' triphosphorique

During the ischemic shock caused by the removal of tourniquets placed on the hind paws of the rat, a marked decrease in the enzyme activities of Krebs cycle yielding ATP (malate dehydrogenase, isocitrate dehydrogenase, succinate dehydrogenase) at the level of the gastrocnemius muscle and the liver, was observed together with a plasma increase of these enzymes. The intraperitoneal injection of ATP diminishes significantly the variations observed.