Isolation in east Senegal of a yellow fever virus strain from a pool of Aedes belonging to the subgenus Diceromyia]

During an epidemiological survey of yellow fever in Eastern Senegal, one strain of yellow fever virus was isolated in December 1976 from wild Mosquitoes. This first isolate obtained in nature from Aedes subgenus Diceromyia shows the primordial part these vectors may have in the area studied. It corroborates the existence of a selvatic focus of yellow fever in this region. It also gives information on the transmission cycle in a dry area.     

Isolation of the yellow fever virus from an egg-cluster and the larvae of the tick Amblyomma variegatum]

The yellow fever virus is isolated in natura from eggs of a Tick Amblyomma variegatum. It is then isolated from larvae issued from the same egg-cluster and also from blood of a monkey bitten by larvae of the same origin. It is reported that the same virus has been previously obtained from adults of the same species of Tick. An acarine appears for the first time as a sylvatic vector and reservoir (at least temporary) of yellow fever.     

Kristalloide Strukturen im Zytoplasma von lymphatischen Zellen verschiedener Affen

Summary In the endoplasmic reticulum of cells of spleen and lymphnodes of different monkeys, crystalloid inclusions were often found. These inclusions show a pattern of small balls with a diameter of 250 Å, which are connected by 100 Å long bridges. It is supposed that these crystalloid inclusions are produced by the lymphatic cells as a reaction to virus infection, which remains clinically non-apparent, because the same pattern was observed in cells, which were experimentally infected with yellow fever virus, West Nile virus, and rubella virus.     

The effect of actinomycin D on the production of viruses by the protoplasts of Chinese cabbage infected in vitro by the yellow mosaic virus of turnips]

Chinese Cabbage (Brassica sinensis L. var. Cantonner) protoplasts were infected by Turnip yellow mosaic virus (TYMV) and inoculated in the presence or absence of actinomycin D. Virus production was determined 40 hrs. after inoculation, the time required for the virus replication cycle to be terminated. While actinomycin D had no effect on TYMV production when present at a concentration of 1 microng/ml, a 50 to 80% inhibition of virus production was noticed at concentrations of the order of 5 to 10 microng/ml, and the inhibition reached 90% with 25 microng/ml.     

Dengue virus life cycle: viral and host factors modulating infectivity

Dengue virus (DENV 1-4) represents a major emerging arthropod-borne pathogen. All four DENV serotypes are prevalent in the (sub) tropical regions of the world and infect 50–100 million individuals annually. Whereas the majority of DENV infections proceed asymptomatically or result in self-limited dengue fever, an increasing number of patients present more severe manifestations, such as dengue hemorrhagic fever and dengue shock syndrome. In this review we will give an overview of the infectious life cycle of DENV and will discuss the viral and host factors that are important in controlling DENV infection.     

Depletion of hypothalamic norepinephrine reduces the fever induced by polyriboinosinic acid: polyribocytidylic acid (Poly I:Poly C) in rats

Administration of either Poly I:Poly C (0.05-0.50 micrograms) or norepinephrine (2-8 micrograms) into the anterior hypothalamic area produced a dose-related fever in rats. The fever induced by Poly I:Poly C was attenuated after selective depletion of norepinephrine in the hypothalamus. However, selective depletion of hypothalamic norepinephrine did not affect the fever induced by intrahypothalamic norepinephrine. The data indicate that Poly I:Poly C may act to induce fever through the endogenous release of norepinephrine from the rat's hypothalamus.     

Die Pterine in der Haut und in den Augen vonSalamandra salamandra nach Aufzucht auf verschiedenfarbigem Untergrund

Summary Concomitantly with the morphological colour-change, larvae of Salamandra salamandra show a quantitative change in their pteridines. After being reared on a yellow background, all pteridines of the skin (isoxanthopterin and its derivatives, yellow pteridine, photosensitive pteridine) increase by about 1/3 as compared with the animals on a black background. In the retinal pigmentlayer especially, the photosensitive pteridine is augmented.     

Variations de salinité chez les anguilles. Modifications duQO2 et des teneurs en cations des tissues hépatiques et rénaux

Summary Respiratory and ionic contents (Na, K, Ca) measurements were performed on hepatic and renal tissues extracted from yellow eels or silver eels.The increase of hepatic O₂ uptake observed on yellow eels when kept in salt water may be the result of water balance disequilibrium.     

Depletion of hypothalamic norepinephrine reduces the fever induced by polyriboinosinic acid: polyribocytidylic acid (Poly I:Poly C) in rats

Summary Administration of either Poly I:Poly C (0.05–0.50 g) or norepinephrine (2–8 g) into the anterior hypothalamic area produced a dose-related fever in rats. The fever induced by Poly I:Poly C was attenuated after selective depletion of norepinephrine in the hypothalamus. However, selective depletion of hypothalamic norepinephrine did not affect the fever induced by intrahypothalamic norepinephrine. The data indicate that Poly I:Poly C may act to induce fever through the endogenous release of norepinephrine from the rat's hypothalamus.This work was supported by grants from the National Science Council (Taipei, Republic of China).     

Zur Kenntnis der Blattlipide vonAcer platanoides L. während der herbstlichen Vergilbung

Summary The lipids of green and yellow leaves ofAcer platanoides L. have been investigated. Yellow leaves were found to contain phytyl linolenate, a further example of the formation of esters containing terpenoid alcohols and unsaturated fatty acids in yellow autumn leaves. The determination af squalene in leaves of the same tree showed an increase of squalene content during the whole season and the autumn colouration. Regarding the leaf lipids we conclude autumn colouration to be characterized by 3 facts: (1) Lipid degradation, (2) formation of esters and (3) accumulation of lipid intermediates.     

Absence of endotoxin-fever but not hyperthermia in Brattleboro rats

I.c.v. administration of bacterial endotoxin produced a fever in the Long-Evans rat but not in the Brattleboro rat. Similar administration of arachidonic acid, prostaglandin E2, prostacyclin, dibutyryl cAMP, norepinephrine, morphine and beta-endorphin caused hyperthermia in both Long-Evans and Brattleboro rats. Variable doses of exogenous arginine vasopressin (AVP) when centrally administered with endotoxin caused fever in the Brattleboro rat. It is suggested that AVP may play an important role in the production and release of endogenous pyrogen.     

Diurnal variation of hue discriminatory capability under artificial constant illumination

Diurnal variation of hue discriminatory capability under artificial constant illumination of 4000 lux was studied with 10 young female adults using the 100-hue test. There were conspicuous diurnal variations in the yellow-blue and red-green systems, with marked reductions of error score in the evening. However, observations of the blue, yellow, green and red systems separately disclosed that there existed clear diurnal rhythms in the blue and green systems, but not in the yellow and red systems. This suggests the existence of diurnal variation in function of the S and M cones responsible for the blue and green hue.     

Course of fever response to repeated administration of sublethal doses of lipopolysaccharides, polyinosinic:polycytidylic acid and muramyl dipeptide to rabbits

The purpose of the present study was to examine the development of tolerance to three structurally dissimilar pyrogens, i.e., lipopolysaccharide (LPS), muramyl dipeptide (MDP) and polyinosinic:polycytidylic acid (poly I:C) in rabbits. The possibility of pyrogenic cross-tolerance among these agents has also been studied. It was observed that repeated injection of sublethal doses of LPS and MDP was connected with the changing of biphasic fever to monophasic. The consequence of this was a drop in the fever index. In contrast to LPS and MDP, the repeated administration of poly I:C did not result in such changes. Successive injections of this pyrogen always evoked biphasic fever. We also demonstrated that pyrogenic cross-tolerance between LPS and MDP did not occur. The cross-tolerance between LPS and MDP did not occur. The cross-tolerance among pyrogens was possible if they originated from the same class, for example endotoxin from Salmonella abortus eq. and endotoxin from Escherichia coli.     

The effect of methyl jasmonate on lycopene and β-carotene accumulation in ripening red tomatoes

Cellular and Molecular Life Sciences - Methyl jasmonate at a concentration of 0.5% in lanolin paste was applied to detached mature green tomatoes cv. Venture. It caused the formation of a yellow...     

Course of fever response to repeated administration of sublethal doses of lipopolysaccharides,polyinosinic: Polycytidylic acid and muramyl dipeptide to rabbits

Summary The purpose of the present study was to examine the development of tolerance to three structurally dissimilar pyrogens, i.e., lipopolysaccharide (LPS), muramyl dipeptide (MDP) and polyinosinic: polycytidylic acid (poly I:C) in rabbits. The possibility of pyrogenic cross-tolerance among these agents has also been studied. It was observed that repeated injection of sublethal doses of LPS and MDP was connected with the changing of biphasic fever to monophasic. The consequence of this was a drop in the fever index. In contrast to LPS and MDP, the repeated administration of poly I:C did not result in such changes. Successive injections of this pyrogen always evoked biphasic fever. We also demonstrated that pyrogenic cross-tolerance between LPS and MDP did not occur. The cross-tolerance between LPS and MDP did not occur. The cross-tolerance among pyrogens was possible if they originated from the same class, for example endotoxin fromSalmonella abortus eq. and endotoxin fromEscherichia coli.     

Lack of pyrogenic tolerance transmission between brain and periphery in the rabbit

Summary Successive injections of lipopolysaccharide (LPS) either intravenously (i.v.) or intracerebroventricularly (i.c.v.) induced pyrogenic tolerance to LPS in rabbits. Tolerance was shown by a decrease of the magnitude of the fever response to repeated doses of LPS, irrespective of the route of pyrogen administration. A significantly greater and more dramatic decrease of the fever index, however, was observed in rabbits made tolerant to pyrogen given i.v. than when the pyrogen was given i.c.v. Transmission of the pyrogenic toleraance between brain and peripheral tissues, however, has not been ascertained.     

Lack of pyrogenic tolerance transmission between brain and periphery in the rabbit

Successive injections of lipopolysaccharide (LPS) either intravenously (i.v.) or intracerebroventricularly (i.c.v.) induced pyrogenic tolerance to LPS in rabbits. Tolerance was shown by a decrease of the magnitude of the fever response to repeated doses of LPS, irrespective of the route of pyrogen administration. A significantly greater and more dramatic decrease of the fever index, however, was observed in rabbits made tolerant to pyrogen given i.v. than when the pyrogen was given i.c.v. Transmission of the pyrogenic tolerance between brain and peripheral tissues, however, has not been ascertained.     

Absence of endotoxin-fever but not hyperthermia in Brattleboro rats

Summary I. c. v. administration of bacterial endotoxin produced a fever in the Long-Evans rat but not in the Brattleboro rat. Similar administration of arachidonic acid, prostaglandin E₂, prostacyclin, dibutyryl cAMP, norepinephrine, morphine and -endorphin caused hyperthermia in both Long-Evans and Brattleboro rats. Variable doses of exogenous arginine vasopressin (AVP) when centrally administered with endotoxin caused fever in the Brattleboro rat. It is suggested that AVP may play an important role in the production and release of endogenous pyrogen.     

Photoelectric properties of the ‘yellow strips’ of social wasps

Summary The yellow strips on the cuticle of social wasp workers become photoconductive following irradiation with light, the effect being perfectly reversible.