[Enzyme immunoassay of ampicillin in milk].

An indirect immunoassay for quantitative determination of ampicillin (range, 10-1000 ng/ml) in buffer or milk has been developed. Polyclonal antibodies were obtained against ampicillin conjugated with bovine serum albumin; the conjugate was synthesized by direct condensation using carbodiimide. The antibodies were specific for ampicillin and exhibited low cross-reactivity to other penicillins (azlocillin, 17%; penicillin G, 10%; piperacillin, 5%; and carbenicillin, 4%). Matrix effects were minimized by combining the use of a casein-supplemented buffer (content of casein, 1%) with sample dilution. The threshold of ampicillin detection in milk (diluted tenfold) was equal to 5.0 ng/ml (which corresponded to 50 ng/ml of the original sample).

[Morphological changes in rat liver in toxic drug-induced hepatitis and stimulation of repair processes]. / Morfologicheskie izmeniia v pecheni krys pri toksicheskom medikamentoznom gepatite i stimuliatsii reparativnykh protsessov.

Despite a large choice of drugs used for the treatment of chronic liver diseases, they often give only a temporary positive effect. In this study the effect of ursodeoxycholic acid on liver regeneration was investigated using the animal model of toxic hepatitis induced by anticonvulsive drug depackin, which is employed in infant neurology. The results of the study demonstrate stimulatory effect of ursodeoxycholic acid on regeneration process in animals' damaged liver, therefore its use may be recommended for the complex treatment of patients with toxic liver lesions.

[The suppression of the contractile activity of the cardiomyocytes by dermorphin in a heart culture of newborn rats]. / Podavlenie sokratitel'noi aktivnosti kardiomiotsitov dermorfinom v kul'ture serdtsa novorozhdennykh krysiat.

Opioid peptides exert ino- and chronotropic effects on the heart. Paraopioid dermorphine (Y-dA-F-G-Y-P-S) was earlier shown to act as negative inotropic agent in isolated frog's hearts. In this study, the same effect was investigated in cultured myocardiac cells of the newborn rats. Dermorphine (10(-4)-10(-9) M) dose-dependently attenuated the contraction amplitude with the latency of 5-10 min. The peak of the response appeared in 30-45 min after application of dermorphine. The mu-opiate-receptor antagonist naloxone (10(-5) g/ml) blocked this effect. Dermorphine seems to exert its negative inotropic action through the opiate receptors, presumably of the mu-subtype.

[Reparative regeneration of rat liver after treatment with bee venom]. / Reparativnaia regeneratsiia pecheni krys pri deistvii pchelinogo iada.

After 70% of the rat liver volume has been resected, certain stimulating effect of a single administration of bee venom (1 mg/kg) on hepatocyte proliferation is revealed. In 4 hours the amount of binuclear hepatocytes increases, and in 22-24 hours increases their mitotic activity. The effect of bee venom is explained as activation of the adenilate cyclase system by means of prostaglandins and adrenal hormones.

[Effect of chorionic gonadotropin on the content of prostaglandins (E + A) in pathologically altered liver tissue and blood of rats]. / Vliianie khorionicheskogo gonadotropina na soderzhanie prostaglandinov (E + A) v tkani patologicheski izmenennoi pecheni i v plazme krovi krys.

Twenty-four and 48 hours after injection of chorionic gonadotropin (CG) the content of prostaglandins E + A in the liver and blood plasma of white random-bred rats with chronic hepatitis increases (both after and without castration). This accounts for some aspects of the mechanism of the CG-induced stimulation of liver regeneration, which results in structural and functional normalization of the organ.