Absence of naturally occurring coronary atherosclerosis in squirrel monkeys (Saimiri sciurea) treated with chondroitin sulfate A

Zusammenfassung Die überraschende Atheromatosehemmende Wirkung von Chondroitin-Sulfat konnte nun auch beiSaimiri scurea, einem Primaten mit hoher Inzidenz von Atheromatose, nachgewiesen werden.

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Supported in part by grants from the Heart Institute of the National Institutes of Health, U. S. Public Health Service, John A. Hartford Foundation, Inc., and other donors.     

Human cdc2 protein kinase is a major cell-cycle regulated tyrosine kinase substrate

cdc2 is a catalytic subunit of a protein kinase complex, called the M-phase promoting factor, that induces entry into mitosis and is universal among eukaryotes. In HeLa cells, cdc2 is shown to be the most abundant phosphotyrosine-containing protein and its phosphotyrosine content is subject to cell-cycle regulation. One site of cdc2 tyrosine phosphorylation in vivo is selectively phosphorylated by pp60c-src in vitro.     

Corticospinal influences on primary afferents during sleep and wakefulness

Riassunto Nel sonno desincronizzato si osserva un aumento della scarica piramidale originante dalle aree somato-sensoriali della corteccia in corrispondenza dei REM. Queste scariche piramidali depolarizzano le fibre afferenti primarie della via riflessa flessoria e verosimilmente contribuiscono alla depressione fasica dei riflessi polisinaptici che si manifesta durante i REM.

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This investigation was supported by PHS research grant NB-02990-04 from the National Institute of the Neurological Diseases and Blindness, N.I.H., Public Health Service (USA).     

Influence of medium viscosity on the oxygen consumption of rat bone marrow cells

Zusammenfassung Der Sauerstoffverbrauch von Kno chenmarkzellen der Ratte in Thyrodelösung (verschiedene Konzentrationen und Molekulargewichte) wurde unter sucht. Zwischen Sauerstoffverbrauch und Viskosität des suspendierenden Mediums oder des Volumens der Zellen konnten keine Beziehungen gefunden werden. Mögliche physiologische Dextranwirkungen auf die Zellaktivität werden diskutiert.     

Congressus

Cellular and Molecular Life Sciences -     

Vestibular origin of the rapid eye movements during desynchronized sleep

Riassunto I movimenti rapidi oculari caratteristici del sonno desincronizzato nel gatto dipendono dall'integrità anatomica e funzionale dei nuclei vestibolari.

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This investigation was supported by PHS research grant NB-02990-04 from the National Institute of Neurological Diseases and Blindness, N.I.H., Public Health Service (USA).     

Positive and negative effects of widespread badger culling on tuberculosis in cattle

Human and livestock diseases can be difficult to control where infection persists in wildlife populations. For three decades, European badgers (Meles meles) have been culled by the British government in a series of attempts to limit the spread of Mycobacterium bovis, the causative agent of bovine tuberculosis (TB), to cattle. Despite these efforts, the incidence of TB in cattle has risen consistently, re-emerging as a primary concern for Britain's cattle industry. Recently, badger culling has attracted controversy because experimental studies have reached contrasting conclusions (albeit using different protocols), with culled areas showing either markedly reduced or increased incidence of TB in cattle. This has confused attempts to develop a science-based management policy. Here we use data from a large-scale, randomized field experiment to help resolve these apparent differences. We show that, as carried out in this experiment, culling reduces cattle TB incidence in the areas that are culled, but increases incidence in adjoining areas. These findings are biologically consistent with previous studies but will present challenges for policy development.     

Competence for genetic transformation in pneumococcus depends on synthesis of a small set of proteins.

In bacterial genetic transformation the uptake of DNA and its integration into the resident chromosome is dependent on a special cellular state, termed competence. In those species where appearance of competence has been studied, specific (but often poorly defined) growth conditions lead to a simultaneous development of competence in a substantial fraction of the cells in a culture. In Bacillus subtilis, and in Haemophilus species, competence appears in the stationary phase of growth or in certain other growth-limiting conditions. Streptococcus pneumoniae (pneumococcus) is perhaps unusual in that virtually all cells of a culture become competent, for a short period at a specific cell density during logarithmic growth, without perturbing the growth rate. The synchronous appearance of competence in pneumococcal cultures results from an autocatalytic effect of a small protein released by the cells that induces competence. The response to competence factor has been shown to require protein synthesis. We report here additional information on the nature of competence in pneumococcus: pulse-labelling studies show that for the brief period of competence protein synthesis is restricted to a few specific polypeptides.     

Stem cells, cancer, and cancer stem cells.

Stem cell biology has come of age. Unequivocal proof that stem cells exist in the haematopoietic system has given way to the prospective isolation of several tissue-specific stem and progenitor cells, the initial delineation of their properties and expressed genetic programmes, and the beginnings of their utility in regenerative medicine. Perhaps the most important and useful property of stem cells is that of self-renewal. Through this property, striking parallels can be found between stem cells and cancer cells: tumours may often originate from the transformation of normal stem cells, similar signalling pathways may regulate self-renewal in stem cells and cancer cells, and cancer cells may include 'cancer stem cells' - rare cells with indefinite potential for self-renewal that drive tumorigenesis.