Beziehungen zwischen phagozytierenden,virusinfizierten Myeloblasten des Huhnes in vitro und den «gray bodies»

Summary The so-called gray bodies in chicken myeloblasts infected with the myeloblastose virus are phagocytized cell debris. Some difficultues concerning this virus-cell-system are pointed out.

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Die Arbeit wurde unterstützt durch Research grant No. C-4572 an die Duke University von National Cancer Institute, National Institutes of Health, Public Health Service, durch Grant No. E-84A von der American Cancer Society, Inc. und durch den Dorothy Beard Research Fund.     

In vitro biosynthesis of beta-lipotropin in brain tissue]

We have recently developed methods to identify biosynthetized beta-endorphin and beta-lipotropin (beta-LPH) following incubation of Rat pars intermedia with radioactive amino acids. We used the same approach for rat brain tissue. In the striatum we found a peptide similar to beta-LPH while its identification in hypothalamus was less positive. This is the first demonstration of such biosynthesis and it could well be an important step in determining the biosynthetic patterns of cerebral endorphins and enkephalins.     

Thrombozytose und Eosinophilie bei adrenalektomierten Ratten nach einmaliger 5-Hydroxytryptamininjektion

Summary In adrenalectomized rats, the injection of a single high dose of 5-hydroxytryptamin results, as in intact animals previously reported, in a strong increase of the number of platelets in the peripheral blood. The number of eosinophils, instead of decreasing, also rises. The maxima of increase are not in temporal accordance.     

«LH-Releasing-Factor» beim Menschen

Summary There is evidence for LH-releasing-factor (LH-RF) in 18 crude acid extracts of human median eminence preparation following the procedure described byRamirez andMcCann.     

Rosette formation in white blood cell cultures from patients with acute myeloblastic leukemia

Zusammenfassung In Monozyten enthaltenden Leukozyten-Kulturen von Patienten mit akuter myeloischer Leukämie entstehen nach ungefähr 8 h Inkubationszeit Rosetten, die aus einem von Myeloblasten umgebenen Monozyten bestehen. In Analogie zu anderen in vitro-Systemen, in welchen sich eine Rosettenbildung beobachten lässt, könnte diese zelluläre Reaktion auf dem Vorhandensein von spezifischen Antikörpern im Patienten-Serum beruhen, welche gegen die leukämischen Myeloblasten gerichtet sind.     

Europe-wide reduction in primary productivity caused by the heat and drought in 2003

Future climate warming is expected to enhance plant growth in temperate ecosystems and to increase carbon sequestration. But although severe regional heatwaves may become more frequent in a changing climate, their impact on terrestrial carbon cycling is unclear. Here we report measurements of ecosystem carbon dioxide fluxes, remotely sensed radiation absorbed by plants, and country-level crop yields taken during the European heatwave in 2003. We use a terrestrial biosphere simulation model to assess continental-scale changes in primary productivity during 2003, and their consequences for the net carbon balance. We estimate a 30 per cent reduction in gross primary productivity over Europe, which resulted in a strong anomalous net source of carbon dioxide (0.5 Pg C yr(-1)) to the atmosphere and reversed the effect of four years of net ecosystem carbon sequestration. Our results suggest that productivity reduction in eastern and western Europe can be explained by rainfall deficit and extreme summer heat, respectively. We also find that ecosystem respiration decreased together with gross primary productivity, rather than accelerating with the temperature rise. Model results, corroborated by historical records of crop yields, suggest that such a reduction in Europe's primary productivity is unprecedented during the last century. An increase in future drought events could turn temperate ecosystems into carbon sources, contributing to positive carbon-climate feedbacks already anticipated in the tropics and at high latitudes.     

Exotoxin in malaria infection (Plasmodium berghei)

Zusammenfassung Swiss Mäuse, die unbehandelt eine Infektion mitPl. berghei niemals überleben, wurden mit Serum von frisch infizierten Tieren (12. Infektionstag) immunisiert und anschliessend infiziert. Obgleich sich danach in allen Fällen eine schwere Parasitämie entwickelte, heilten 44% derjenigen Tiere nach dem 35. Infektionstag spontan aus, die mit 3 mg Serumprotein/Maus immunisiert waren. Wegen der offensichtlich eingetretenen Immunoblockade überlebten dagegen nach Immunisation mit höheren Proteinmengen (mehr als 30 mg per Maus) keine Tiere.