Cristallisation de l'α-amylase de pancréas

Summary In a series of 32 urinary calculi, examined with X-rays and microscope, 2 were found to consist of hydroxylapatite, 4 of whewellite, 4 of struvite and 15 of uric acid. 4 stones contained two minerals: apatite + brushite, apatite + whewellite and both hydrates of Ca-oxalate.     

Genomic sequence of the pathogenic and allergenic filamentous fungus Aspergillus fumigatus

Aspergillus fumigatus is exceptional among microorganisms in being both a primary and opportunistic pathogen as well as a major allergen. Its conidia production is prolific, and so human respiratory tract exposure is almost constant. A. fumigatus is isolated from human habitats and vegetable compost heaps. In immunocompromised individuals, the incidence of invasive infection can be as high as 50% and the mortality rate is often about 50% (ref. 2). The interaction of A. fumigatus and other airborne fungi with the immune system is increasingly linked to severe asthma and sinusitis. Although the burden of invasive disease caused by A. fumigatus is substantial, the basic biology of the organism is mostly obscure. Here we show the complete 29.4-megabase genome sequence of the clinical isolate Af293, which consists of eight chromosomes containing 9,926 predicted genes. Microarray analysis revealed temperature-dependent expression of distinct sets of genes, as well as 700 A. fumigatus genes not present or significantly diverged in the closely related sexual species Neosartorya fischeri, many of which may have roles in the pathogenicity phenotype. The Af293 genome sequence provides an unparalleled resource for the future understanding of this remarkable fungus.     

Trapping an atom with single photons

The creation of a photon-atom bound state was first envisaged for the case of an atom in a long-lived excited state inside a high-quality microwave cavity. In practice, however, light forces in the microwave domain are insufficient to support an atom against gravity. Although optical photons can provide forces of the required magnitude, atomic decay rates and cavity losses are larger too, and so the atom-cavity system must be continually excited by an external laser. Such an approach also permits continuous observation of the atom's position, by monitoring the light transmitted through the cavity. The dual role of photons in this system distinguishes it from other single-atom experiments such as those using magneto-optical traps, ion traps or a far-off-resonance optical trap. Here we report high-finesse optical cavity experiments in which the change in transmission induced by a single slow atom approaching the cavity triggers an external feedback switch which traps the atom in a light field containing about one photon on average. The oscillatory motion of the trapped atom induces oscillations in the transmitted light intensity; we attribute periodic structure in intensity-correlation-function data to 'long-distance' flights of the atom between different anti-nodes of the standing-wave in the cavity. The system should facilitate investigations of the dynamics of single quantum objects and may find future applications in quantum information processing.     

On the chemical nature of acerin and the virucidal and antiviral effects of some vegetable tannins

Zusammenfassung Die viruzide Wirkung von Extrakten aus Ahornsamen auf Coli-Bakteriophagen ist durch Tannine bedingt. Verschiedene Gerbstoffe zeigen einen zum Teil sehr starken virushemmenden Effekt, wobei nur das extrazelluläre Virus angegriffen wird. Wahrscheinlich handelt es sich um eine Gerbwirkung auf das Protein des Virus.Die pflanzlichen Gerbstoffe tragen vermutlich dazu bei, die Pflanzensäfte virusfrei zu halten.

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While this paper in print, our attention was called to a recent publication in J. Bact. (66, 572 1953) byCarson andFrisch about the growth inhibiting action of tannic acid on influenza virusin ovo. We were ignorant of this work and of the previous publication from 1948 byGreen, Proc. Soc. Exptl. Biol. Med.67, 483 (1948).     

Über eine neue Herstellung aromatisch substituierter Reduktone

Summary Equimolecular amounts of an aromatic or hetero-cyclic aldehyde, glyoxal and cyanideion combine in slightly alkaline aqueous solution to give 4-aryl-2-hydroxytetronimides (I). These are cyclic reductones comparable to imino-ascorbic acid. Oxidation yields dehydro compounds (III) (4-aryl-2, 3-dioxo-4-hydroxy-butyric acid lactones); hydrolysis gives 4-aryl-2-hydroxy-tetronic acids (V) which are easily decarboxylated to -aryl-lactic acids (VII). On hydrogenation, the compounds I are converted to -aryl-, -dihydroxy-butyramides.     

Role of the pituitary in cyproheptadine-induced pancreatic beta-cell toxicity

Summary Hypophysectomized rats given cyproheptadine (40 mg/kg) for 10 days exhibited a loss of pancreatic immunoreactive insulin and ultrastructural changes in the cytoplasm of beta-cells. Sham-operated animals given cyproheptadine showed identical changes in pancreatic beta-cells except that cytoplasmic involvement progressed to the formation of large vacuoles. The pituitary is not directly involved with the cyproheptadine-induced depletion of pancreatic insulin but plays a role in the formation of large cytoplasmic vacuoles.Acknowledgments. This work was supported by U. S. Public Health Service, grant GM 12675.     

Continuous registration of the pancreatic blood flow after intravenous application of glucose

Zusammenfassung Die Hyperglykämie nach einmaliger stossartiger Glukoseinjektion bewirkt einen Durchblutungsanstieg der Bauchspeicheldrüse. Dieser wurde kontinuierlich mit einem elektromagnetischen Blutstrommesser bei narkotisierten Hunden registriet. Der Anstieg setzt sich aus 2 Abschnitten zusammen, wovon der erste unspezifisch auch in der A. femoralis auftritt.