Influence of the viscous substance at the tip of the labellar hairs ofPhormia regina M. on the effectiveness of stimulation by cations and anions

Summary The stimulating effectiveness of salt solutions on the labellar taste hairs ofPhormia regina M. is discussed on the basis of ion diffusion properties across the mucopolysaccharidic layer at the hair tip.This work is partly supported by a grant from the Consiglio Nazionale delle Ricerche (CNR), Roma, Italy.     

Influence of a high-temperature environment on the development of experimental trypanosomiasis of the mouse]

Different evolutions of experimental trypanosomiasis are observed in Mice kept in a permanent 35 degrees C environment. Evolution depends on the individuality or the strain of the host animal. An experimental factor influence on the host mechanism defense rather than on the parasite multiplication rate is shown.     

Influence of clonidine on experimental hypertension induced by cholinergic stimulation

Summary Hypertension may be induced by pharmacologic activation of central cholinergic receptors either indirectly, through the injection i.v. of physostigmine, or directly, through the injection i.v. of arecholine in anesthetized rats. Activation of peripheral preganglionic cholinergic receptors with dimethylphenylpiperazinium iodide (DMPP) also produced a hypertensive response. Pretreatment with various doses of clonidine caused inhibition of the pressor response to central cholinergic stimulation but was without effect on the response to ganglionic cholinergic stimulation.     

Influence of age on the plasma hormonal iodine response to thyrotropin injection in young calves]

The influence of age upon the increase in plasma hormonal iodine level following an intravenous injection of bovine TSH (0.2 USP units/kg) was studied in young jersey calves. The response to TSH increased between birth and the 7th day, then decreased regularly until the end of the third month. Reasons for these variations are discussed according to some results obtained following TSH injections.     

Oculomotor reflex evoked by vibrassae stimulation in the cat]

The oculomotor effects of vibrissae stimulation have been studied in the "encéphale isolé" non-anaesthetized Cat. Intracellular recording of lateral rectus motoneurones showed an excitatory projection via the ipsilateral infraorbital nerve to these motoneurones. The afferent fibers are type A alpha, recuited with a low threshold (0.2-0.5 mA) and convey information about vibrissae displacement.     

Facilitation of avoidance conditioning by reticular stimulation in the cat]

Learning is facilitated in Cats by posttrial reticular stimulation. It has been pointed out that this stimulation has no immediate anterograde effect and does not evoke any change in the cortical, motor or autonomic functions during its delivery. Moreover this stimulation has no effect on the time course of cortical and autonomic responses to the conditioned stimulus. Therefore, these results suggest that reticular stimulation has a specific action on memory consolidation or information processing.     

Influence of diglycyl-glycine on the radiation sensitivity of catalase

Zusammenfassung Die Veränderung der Strahlenempfindlichkeit von Katalase durch Diglycyl-glycin wurde spektralphotometrisch untersucht. Die Bestrahlungsdosen variierten zwischen 0–2,7 × 10⁶ r. Der Schutzeffekt lässt sich durch einen Radikal-abfangenden Mechanismus erklären. Strahlenbiologische Folgerungen werden diskutiert.     

Influence of ionizing radiation on protein production by HeLa cells in culture

Zusammenfassung Bei der Züchtung von HeLa-Krebszellen in tritiumhaltiger Nährlösung während 48 h wurde festgestellt, dass die Mitoserate durch viel kleinere Strahlendosen nachweisbar herabgesetzt wird als die radiochemisch gemessene Rate der Proteinsynthese.     

Influence of a hot environmental temperature on the evolution of experimental paludism of the mouse with Plasmodium berghei berghei]

Swiss Mice infected with Plasmodium berghei berghei and maintained in permanence in a hot environmental temperature undergo a chronic infection whereas controls maintained at the laboratory temperature develop always an acute and lethal infection. The hot environmental temperature does not seem to have any action on the pathogenicity of the parasites. Host defences are stimulated.     

Influence of serotonin on the radiation sensitivity of lactate dehydrogenase

Zusammenfassung Die Veränderungen in der Strahlenempfindlichkeit von Milchsäuredehydrogenase durch Serotonin, gebraucht als Serotonin-Kreatinin-Sulfat, wurden spektralphotometrisch untersucht. Die Bestrahlungsdosen variierten zwischen 0–9 · 10⁵ R. Die Serotonin-Konzentrationen variierten zwischen 0–1,23 mM. Die D³⁷-Dosis für eine Serotonin-Konzentration von 246M ist ca. 34mal grösser als für die Kontrollen. Der Schutzeffekt kann durch eine Komplexbildung zwischen Serotonin und den Metallionen, die im Enzym-Molekül vorhanden sind, erklärt werden.     

Detection of human antigens on the surface of mouse cells transformed by chromosome transfer]

Mouse embryo cells, transformed in vitro by the transfer of chromosomes from HeLa human tumour cells, express a surface antigen (s) also found on HeLa cells. This antigen(s), which has been detected both by indirect immunofluoresence and by a 125I-protein A binding assay, is not an antigen(s) shared by both Human and Mouse cells.     

Influence of halogenated deoxyuridines on the radiation sensitivity ofEscherichia coli

Zusammenfassung Halogenierte Deoxyuridine IUDR, BUDR und FUDR wurden im Medium als bakterielle Sensibilisatoren für Röntgenstrahlen untersucht. Es wird gezeigt, dass nur IUDR als Sensibilisator funktionieren kann, scheinbar sowohl durch die Bildung des langlebigen giftigen molekularen Jods als auch durch die Bildung des kurzlebigen giftigen Jod-Atoms.

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This work was supported in part by an institutional grant from the U.S. National Cancer Institute, No. CA-08748 and by a grant from the U.S.Atomic Energy Commission, No. AT(30-1)910.     

Influence of thalamic stimulation on cortical epileptogenic focus

Summary Single stimuli applied to the non-specific thalamic nuclei do not change the activity of a cortical epileptogenic focus whereas rhythmic stimulation of these structures transforms the interictal activity into an ictal one.     

Cellular fusion induced in vitro by the mouse scrapie agent]

A method is described to demonstrate and measure the cell-fusion in vitro induced by viruses. This technique has been established using Sendai virus. It has been used to study the fusing ability of the Scrapie agent which is responsible of a slowly progressing spongiform encephalopathy in Mice. In Vero cells, the Scrapie agent induces a fusion which appears slowly and remains moderate. This test can help to detect the human spongiform encephalopathies.