l-Isoleucine: An inducer of the feeding response in decapod crustaceans

Zusammenfassung Es wird gezeigt, dassl-Isoleucin eine starke Fressreaktion bei 6 Arten dekapoder Krebse hervorruft. Die wirksame Konzentration dieser Substanz war unter 2,3×10^–6 M/l.     

Non-mendelial female sterility in Drosophila melanogaster: demonstration of an inducer chromosome 4]

Crosses between two classes of Drosophila melanogaster strains (reactive and inducer) may lead to partially sterile F1 females. This sterility, called S.F. sterility, can be characterized by its physiological features. It appears to be the result of an interaction between two factors: "R" brought into the initial croos by the reactive mother and "I" by chromosomes of the inducer father. Except for chromosome 4, each chromosome of the well known inducer strains may carry the I factor (inducer chromosomes). The present results provide evidence for the presence of an inducer fourth chromosome in the inducer strain Nagasaki.     

5-Hydroxytryptophan-decarboxylase activity in the decapod crustaceanUpogebia littoralis

Zusammenfassung Die Aktivität der 5-HTP Dekarboxylase in Rohextrakten verschiedener Organe vonUpogebia littoralis wurde radiochemisch bestimmt. Die grösste Aktivität des Enzyms findet sich in den Stielaugen, während stielaugenlose Köpfe die niedrigste Enzymaktivität zeigen.     

Phorbol esters enhance glutathione-induced feeding response in Hydra

Summary Pharmacological observations on the glutathione-induced feeding response in Hydra demonstrate that phorbol esters, calcium ionophore A 23187 and lithium ions significantly enhance and protract glutathione action, whereas polymixin B induces a dramatic shortening of the feeding response. An involvement of membrane phosphatidylinositol breakdown in the control of the feeding response is suggested.     

Intrinsic and extrinsic neural and neurohumoral control of the decapod heart

The intra-cardiac nervous system of the decapod heart is composed of large and small ganglionic cells (LGCs and SGCs) and axons of extrinsic cardio-acceleratory and-inhibitory neurons (CAs and CIs). Candidate neurotransmitters for the neurons have been determined by pharmacological, cytochemical and immunocytochemical tests. SGCs may be cholinergic, LGCs and CAs are probably dopaminergic, and CIs are GABAergic. Serotonin and octopamine were cardio-excitatory neuromodulators of the heart. Proctolin, crustacean cardio-active peptide (CCAP), red pigment concentrating hormone (RPCH), and FMRFamide also had modulatory actions on the heart. Proctolin was the most potent peptide, which acted primary on the cardiac ganglion. Insect adipokinetic hormones had little effect on the heart.     

Limulus chromatophorotropin: action on isolated Uca legs and in various crustaceans.

Limulus CNS chromatophorotropin causes melanin dispersion in isolated legs of Uca. Theophylline potentiation of extract activity suggests that the material may act through the adenylate cyclase-cAMP system. The extracts are also active on the chromatophores of 7 decapod species from 6 families.     

The effect of serotonine and 5-hydroxytryptophan on the erythrophores of crustaceans

Zusammenfassung Es wird gezeigt, dass Serotonin (5-Hydroxytryptamin) beim Hervorrufen der Pigmentausbreitung in den grossen Garnelen-Erythrophoren eine wichtige Rolle spielt. Versuche zeigen, dass diese Crustaceen vielleicht 5-Hydroxytryptophan in Serotonin umwandeln können.     

Variation of the inflammatory response of an autologus implant function and viability: mixed and unilateral inflammatory response]

The behaviour of an autologous grafted implant depends upon its viability. In our study, pericardial implants were used as cardiac valves. Results showed that when using fresh live pericardium, an inflammatory response developed destroying it within 8 days. When implants cells were killed without alteration of their antigenicity--in order to prevent rejection--cellular growth and neovascularisation from implantation site occurred leading to a secondary live graft. Controlled killing of the implant seems to be an essential step in order to get live grafts.     

2-Carboxyethylgermanium sesquioxide,a synthetic organogermanium compound,as an inducer of contrasuppressor T cells

2-Carboxyethylgermanium sesquioxide (Ge-132), a synthesized organogermanium compound with immunomodulaing activities, was shown to be an inducer of anti-suppressor T cells in normal mice. The suppressor cell activity of T6S cells, a clone of burn-induced CD8⁺ IL-4-producing suppressor T cells, was clearly inhibited when a mixed lymphocyte-tumor cell reaction of the clone was conducted with splenic mononuclear cells from mice treated orally with a 100 mg/kg dose of Ge-132. The activity of anti-suppressor cells was demonstrated in spleens of mice 2 days after treatment with Ge-132 and reached its peak on day 3. The anti-suppressor cells induced by the compound were of a contrasuppressor T cell-linage, because they were characterized as CD4⁺ CD28⁺ TCR/⁺ Vicia villosa lectin-adherent T cells. These cells produced IFN- but did not produce IL-2, IL-4, IL-6 or IL-10 in their culture fluids. CD4⁺ anti-suppressor T cells induced by Ge-132 may be different from other subsets of CD4⁺ T cells because Th1 and Th2 cells generated in our laboratory did not adhere toVicia villosa lectin-coated petri dishes, and each produced specific cytokines. Th1 cells produced IFN- and IL-2 while Th2 cells produce IL-4 and IL-10 in vitro. These results suggest that Ge-132 may be useful as an inducer of contrasuppressor T cells in immunocompromised individuals bearing suppressor T cells. To eliminate suppressor T cells from immunocompromised hosts may result in improved resistance from various opportunistic infections.     

Repair of integumental lesions in the decapod crab,Carcinus maenas (L.), in the presence of molting hormone

Summary Epicuticle is not included as any part of the repair cuticle that closes integumental lesions in crabs receiving multiple injections of molting hormone (20-hydroxyecdysone) before and/or after damage to the integument. It is suggested that deposition of the exclusively lamellate material of repair cuticle is mediated by some epidermal factor(s) rather than by external, humoral influences.     

A hypothesis concerning the use of colchicine as a polyploidy inducer

Résumé Le développement de la racine et de la coléoptile est stimulé lorsque des plantules de Graminées sont incubées avec la colchicine à des concentrations audessous du seuil qui produit ses effets mutagéniques. Cette stimulation de la croissance — qui semble être due à une activité méristématique accrue — met en évidence un double aspect du méchanisme d'action de la colchicine: la stimulation de la prolifération cellulaire, suivie de l'induction de la polyploïdie. En outre, ceci suggère que le traitement des organes avec des doses de colchicine chaque fois plus élevées devrait permettre d'augmenter le nombre de cellules polyploïdes dans les tissus.

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This work has been supported by a research grant from the National Research Council of Canada.