Antigenic determinants of beta-LPH, beta-MSH, alpha-endorphin, ACTH and alpha-MSH revealed by anti-beta-endorphin in neurons of the human infundibular nucleus]

Comparison of adjacent serial sections of the tubero-infundibular region of Human adult hypothalamus demonstrates that the same perikarya, axons and terminals are stained both with anti-beta-endorphin and anti 17-39 ACTH antisera. The most immunoreactive of these neurons are also revealed with anti alpha-endorphin, anti alpha and beta-MSH, anti-1-24 ACTH and anti beta-LPH. These results suggest that neurons of the infundibular nucleus can store and probably secrete peptide similar to propiocortin or fragment(s) of this molecule.     

Immunofluorencence localization of secretions related to gonadotropic, corticotropic, melanotropic and somatotropic hormones in hypophysis of Nectophrynoides occidentalis]

In Nectophryno?des occidentalis, ovine anti-LH anti beta (1-24) corticotropin, both anti alpha and anti beta MSH and bovine anti-STH antisera allowed us to identify by immunofluorescence gonadotropic, corticotropic, melanotropic and somatotropic hypophysial cells of a viviparous toad. The identification of these different cell types was confirmed by applying a classical cytologic technique to the same sections.     

Localization of immunoreactive sites with anti met-enkephalin and anti alpha-endorphin sera in carp brain]

In the brain of the Carp an anti met-enkephalin serum reveals some telencephalic fibres, about half of the N.P.O. cells and furthermore a subependymal zone of nervous tissue close to the third ventricle of the superior hypothalamus and thalamus. These structures do not react with an anti alpha-endorphin serum, which however reveals cells of the lateral N.L.T. and the corresponding fibres.     

Immunocytochemistry of pituitary corticotroph cells in terrestrial turtle (Testudo mauritanica)]

The immunocytochemical and histochemical characters of the corticotroph cells of the Turtle adenohypophysis have been studied. These cells are localised in the rostral part of the gland and are revealed by Is anti ACTH (1-24) and (17-39). They are also colored with lead hematoxyline and PAS-Orange G. The corticotroph nature of these cells is confirmed by the study of their modifications after treatment with amphenone and ACTH. The Is anti ACTH also reveal most of the cells of the pars intermedia; while the Is anti beta-MSH reveals only these cells and some scatter cells of the pars distalis.     

Stereoselectivity of a radioimmunoassay for the insecticide S-bioallethrin

The stereoselectivity of a radioimmunoassay (RIA) system using an S-bioallethrin specific antiserum was studied by observing the abilities of the 8 allethrin isomers and other selected compounds to compete with a radiolabelled S-bioallethrin tyramine derivative for antibody binding sites. The results demonstrate the feasibility of RIA as a rapid, sensitive and steroselective residue technique for compounds difficult to analyze by classical methods.     

Histamine et carbures cancérigènes

Summary Histamine, which is a constituent of neurons shows a particular affinity for cancer-producing substances but not for the non-cancer-producing isomers of such substances.     

Struktur und Wirkung des Muscarins,des Muscarons und ihrer Stereoisomeren

Summary All synthetic isomers of (+)-muscarine, the racemic forms of epi-muscarine, allo-muscarine, and epiallo-muscarine are at least 100 times less potent on blood pressure of cats and isolated frog hearts than the natural alkaloid. Only muscarones are more potent and exhibit strong nicotinic action on the frog rectus and in blocking ganglionic and neuro-muscular transmission in the cat. They closely resemble acetylcholine in their structure and action.The activity of the isomers depends on the position of the constituents on the tetrahydrofurane ring. Steric hindrance of the hydroxy or carbonylgroup and of etheroxygen plays an important part in the contact with the cholinergic receptor. As nor-muscarine without the quarternary nitrogen is inactive, at least 3 different points of contact have to be considered. This is stressed by the fact that muscarine is highly stereospecific in its action, whereas muscarone is not.     

Occurrence of DDT and BHC residues in human milk in India

The presence of pesticide residue of DDT and of BHC were determined in 1979 in samples of milk from 75 lactating mothers from Punjab, within a week after delivery. DDT and BHC residues were found present in all 75 samples collected. Recovery of isomers of BHC and metabolites/isomers of p.p'-DDT from the spiked samples was above 80%. The mean level of DDT residue was 0.51 ppm, which is more than the level reported from the U.S., Canada, Europe and Australia, but less than the level found in Guatemala. BHC residues also were higher than those found in other countries, with the exception of Japan. DDT level of 0.5 ppm in milk represents an infant intake of 0.09 mg/kg/day, which is 18 times the acceptable daily intake (0.005 mg/kg/day) recommended by the WHO. Acceptable daily intake of BHC has not yet been established.     

Stereoselectivity of a radioimmunoassay for the insecticide S-bioallethrin

Summary The stereoselectivity of a radioimmunoassay (RIA) system using an S-bioallethrin specific antiserum was studied by observing the abilities of the 8 allethrin isomers and other selected compounds to compete with a radiolabelled S-bioallethrin tyramine derivative for antibody binding sites. The results demonstrate the feasibility of RIA as a rapid, sensitive and stereoselective residue technique for compounds difficult to analyze by classical methods.This work was supported in part by grant No. 5-R01-ES01260-02 from the National Institutes of Health.     

In vitro mutagenicity of the soil nematicide 1,3-dichloropropene.

The cis- and trans-isomers of 1,3-dichloropropene have been tested in the Ames mutagenicity assay system on Salmonella typhimurium tester strain TA 1535. Both isomers have been found to be mutagenic even without microsomal activation.     

Formation of a depside-caffeine complex during cold conservation of coffee leaf samples in a hydro-ethanolic medium. Methodologic implications for the extraction of depsides]

The depsides present in coffee leaves are not apparent upon extraction with ethanol if the plant material has been fixed in boiling ethanol then maintained at - 25 degrees C. A complex formed with cafein prevents the extraction and this artefact from cold conservation concerns chlorogenic acid and its isomers. A treatment with chloroform can break the complex and allows the depsides to be dosed. The complex does not seem to exist in living tissues.     

Immunocytological localization of peptide analogs of alpha-endorphin in several neurons of the lateral nucleus tuberis of Carassius auratus L. and Cyprinus carpio L.]

Neurons of the pars lateralis of the N.L.T. of Carassius auratus and Cyprinus carpio display a positive immunocytological reaction with an anti alpha-endorphin serum. It is assumed that the peptides produced by these neurons are similar, if not identical, with alpha-endorphin, but their morphinomimetic properties have still to be established. Peptides of this kind may participate in the regulation of pituitary functions.     

(3H) spiroperidol binding decreases in brains of rats infected with Venezuelan equine encephalomyelitis virus1

Summary After i.p. inoculation with the Guajira strain of Venezuelan equine encephalomyelitis virus a significant decrease in the density of (³H) spiroperidol binding sites in the striatum, midbrain and frontal cortex was observed. No changes in the affinity of the receptors could be demonstrated. This finding is compatible with neuronal degeneration caused by the viral infection.Acknowledgments. This work was partially supported by Condes-Luz and Fundacite-Zulia. Butaclamol isomers were a gift of Ayerst Laboratories, Montreal, Canada.     

Inhibition of pig kidney dopa decarboxylase by coenzyme-5-hydroxytryptophan adducts

The effect of N-(5'-phosphopyridoxyl)-L-5-hydroxytryptophan, N-(5'-phosphopyridoxyl)-D-5-hydroxytryptophan and N-(5'-phosphopyridoxyl)-5-hydroxytryptamine on the reactivation of apoDopa decarboxylase to holoenzyme has been investigated. The different degree of inhibition exerted by these adducts has been interpreted on the basis of a different orientation of the 2 isomers of 5-HTP at the active of Dopa decarboxylase.     

Analogies between "fraction P" with immunosuppressive properties in pregnant females and a protein fraction induced by estradiol treatment in the amphibian Salamandra salamandra L

A "fraction P" analogue possessing immunosuppressive properties during pregnancy in the Salamandra, can be induced by treating males and females with oestradiol. Both fractions possess the same physiochemical characteristics, and equally react against a Rabbit immune serum anti "fraction P" of pregnant Salamandra. But the proteic fraction induced by hormonal treatment does immunosuppressive properties.     

Quantitative differences in the pharmacological effects of (+)- and (-)-cathinone

The optically pure isomers of cathinone were prepared by separating synthetic cathinone racemate and used to study central and peripheral effects of these indirect sympathomimetics in rats and guinea pigs. The (-)-isomer was significantly more potent than the (+)-isomer in stimulating locomotor activity whereas no difference was observed with respect to their cardiac effects. In analogy to observations with (+)- and (-)-amphetamine such variable isomer discrimination may be due to different stereoselectivities of amine uptake mechanisms in the target tissues.     

A comparison of the effects of the optical isomers of isoproterenol on energy metabolism in a mouse sarcoma

Disturbance to energy production in the S180 sarcoma (CB) by optical isomers of isoproterenol was assessed from altered adenine nucleotide levels at 1 h. The L-isomer almost halved the ATP level and lowered the energy charge significantly; the D-isomer was inactive. Dependence of tumor injury on cytochrome P-450 activity appears unlikely.     

Tyrosinase-catalyzed conjugation of dopa with glutathione

A convenient method is described for the preparation of 5-S- and 2-S-glutathionyldopa, based on tyrosinase oxidation of dopa in the presence of glutathione. The yields of 5-S, 2-S, and 6-S isomers produced were about 76, 12, and 5%, respectively.     

Quantitative differences in the pharmacological effects of (+)- and (−)-cathinone

Summary The optically pure isomers of cathinone were prepared by separating synthetic cathinone racemate and used to study central and peripheral effects of these indirect sympathomimetics in rats and guinea pigs. The (–)-isomer was significantly more potent than the (+)-isomer in stimulating locomotor activity whereas no difference was observed with respect to their cardiac effects. In analogy to observations with (+)- and (–)-amphetamine such variable isomer discrimination may be due to different stereoselectivities of amine uptake mechanisms in the target tissues.     

Inhibition of sensitized leukocyte's in vitro reactivity by circulating immune complexes in prostate cancer

Circulating immune complexes in the sera of patients with confirmed histological diagnosis of carcinoma of the prostate, were found to interfere in the sensitized leukocyte's in vitro reactivity to prostate cancer associated antigen as evaluated by tube leukocyte adherence inhibition assay, thereby suggesting an inhibitory role of such serum factors in host's anti tumor cell mediated immune responses.