Full-genome RNAi profiling of early embryogenesis in Caenorhabditis elegans

A key challenge of functional genomics today is to generate well-annotated data sets that can be interpreted across different platforms and technologies. Large-scale functional genomics data often fail to connect to standard experimental approaches of gene characterization in individual laboratories. Furthermore, a lack of universal annotation standards for phenotypic data sets makes it difficult to compare different screening approaches. Here we address this problem in a screen designed to identify all genes required for the first two rounds of cell division in the Caenorhabditis elegans embryo. We used RNA-mediated interference to target 98% of all genes predicted in the C. elegans genome in combination with differential interference contrast time-lapse microscopy. Through systematic annotation of the resulting movies, we developed a phenotypic profiling system, which shows high correlation with cellular processes and biochemical pathways, thus enabling us to predict new functions for previously uncharacterized genes.     

Anthrax kills wild chimpanzees in a tropical rainforest

Infectious disease has joined habitat loss and hunting as threats to the survival of the remaining wild populations of great apes. Nevertheless, relatively little is known about the causative agents. We investigated an unusually high number of sudden deaths observed over nine months in three communities of wild chimpanzees (Pan troglodytes verus) in the Ta? National Park, Ivory Coast. Here we report combined pathological, cytological and molecular investigations that identified Bacillus anthracis as the cause of death for at least six individuals. We show that anthrax can be found in wild non-human primates living in a tropical rainforest, a habitat not previously known to harbour B. anthracis. Anthrax is an acute disease that infects ruminants, but other mammals, including humans, can be infected through contacting or inhaling high doses of spores or by consuming meat from infected animals. Respiratory and gastrointestinal anthrax are characterized by rapid onset, fever, septicaemia and a high fatality rate without early antibiotic treatment. Our results suggest that epidemic diseases represent substantial threats to wild ape populations, and through bushmeat consumption also pose a hazard to human health.     

Integration of quanta in cerebellar granule cells during sensory processing

To understand the computations performed by the input layers of cortical structures, it is essential to determine the relationship between sensory-evoked synaptic input and the resulting pattern of output spikes. In the cerebellum, granule cells constitute the input layer, translating mossy fibre signals into parallel fibre input to Purkinje cells. Until now, their small size and dense packing have precluded recordings from individual granule cells in vivo. Here we use whole-cell patch-clamp recordings to show the relationship between mossy fibre synaptic currents evoked by somatosensory stimulation and the resulting granule cell output patterns. Granule cells exhibited a low ongoing firing rate, due in part to dampening of excitability by a tonic inhibitory conductance mediated by GABA(A) (gamma-aminobutyric acid type A) receptors. Sensory stimulation produced bursts of mossy fibre excitatory postsynaptic currents (EPSCs) that summate to trigger bursts of spikes. Notably, these spike bursts were evoked by only a few quantal EPSCs, and yet spontaneous mossy fibre inputs triggered spikes only when inhibition was reduced. Our results reveal that the input layer of the cerebellum balances exquisite sensitivity with a high signal-to-noise ratio. Granule cell bursts are optimally suited to trigger glutamate receptor activation and plasticity at parallel fibre synapses, providing a link between input representation and memory storage in the cerebellum.     

Transport of the synthetic peptide DSIP through the blood-brain barrier in rabbit

Summary The synthetic delta sleep inducing peptide (DSIP) passes the blood-brain barrier, since i.v. injection in free moving rabbits (30 nmoles/kg) significantly increases the cortical delta activity and decreases the motor activity during 5 h.Acknowledgment. This work was supported by grants from the Swiss National Science Foundation (Nos 3.871-72, 3.525.75, 3.443.074, 3.780.076), Fonds für Lehre und Forschung der Universität Basel, Merck Sharp and Dohme (USA), Ciba-Stiftung Basel.     

Production of pectolytic and cellulolytic enzymes byCercosporella herpotrichoides fron

Zusammenfassung In Kulturfiltraten vonCercosporella herpotrichoides, dem Erreger der Halmbruchkrankheit des Weizens, wurden folgende Enzyme nachgewiesen: Polygalacturonase, Pektinmethylesterase, Pektin-Lyase und Cellulase. Es wird vermutet, dass diese Enzyme, die in einigen Eigenschaften kurz charakterisiert werden, für die Pathogenese von Bedeutung sind.

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This work was supported by a grant from the Deutsche Forschungsgemeinschaft.     

Erythrocytäre Anionenkonzentrationen bei renaler Insuffizienz

Summary In chronic renal insufficiency, concentrations of chloride and inorganic phosphate in human red blood cells are elevated. There is no correlation between serum non-protein nitrogen and the anionic concentrations of red blood cells. Positive correlations exist between corresponding cellular and extracellular anionic concentrations.     

Acute effect of thyrotrophic hormone on the concentration of succinic acid dehydrogenase and sulfhydryl groups in the thyroid gland of the rat

Zusammenfassung Es wurde die Wirkung einer TSH-Injektion auf den Gehalt der Bernsteinsäuredehydrogenase und der SH-Gruppen in der Schilddrüse der Ratte untersucht. 4 h nach der Injektion von TSH erfolgte ein signifikanter Anstieg der Bernsteinsäuredehydrogenase und SH-Gruppen. Die Methode ist deshalb zur Untersuchung der Schilddrüsenaktivität im kurzfristigen Versuch geeignet.

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Aided by a grant from the Sigrid Jusélius Stiftelse.     

Use of mono-layer preparations in studies of nucleolar morphology in pancreatic islet cells

Zusammenfassung Die Untersuchung an endokrin wirksamen Zellen der Bauchspeicheldrüse bei normalen und adipösen Mäusen ergibt eine relative Vergrösserung des Nukleolus der endokrinen Zellen bei den adipösen Tieren, was als morphologisches Zeichen gesteigerter Insulinproduktion angesehen wird.     

Verhalten des Eisenstoffwechsels unter experimentellem Stress. Methodik zur Bestimmung des «non-haem»-Eisens im Gewebe

Summary The non-haemin iron was extracted from tissues by hot hydrochloric acid and determined by sulphonated bathophenanthrolin disodium salt. This method is of reasonable sensitivity, not influenced by haemoglobin iron and gives well-reproducible results.