West Nile Virus and California Breeding Bird Declines

Since it was first detected in 1999, West Nile virus (WNV) quickly spread, becoming the dominant vector-borne disease in North America. Sometimes fatal to humans, WNV is even more widespread among birds, with hundreds of species known to be susceptible to WNV infection in North America alone. However, despite considerable mortality and local declines observed in American crows (Corvus brachyrhynchos), there has been little evidence of a large regional association between WNV susceptibility and population declines of any species. Here we demonstrate a correlation between susceptibility to WNV measured by large-scale testing of dead birds and two indices of overall population change among bird species following the spread of WNV throughout California. This result was due primarily to declines in four species of Corvidae, including all species in this family except common ravens (Corvus corax). Our results support the hypothesis that susceptibility to WNV may have negative population consequences to most corvids on regional levels. They also provide confirmation that dead animal surveillance programs can provide important data indicating populations most likely to suffer detrimental impacts due to WNV.     

Release of pituitary melanocyte-stimulating hormone by the oxytocin fragment, H-Cys-Tyr-Ile-Gln-Asn-Oh

The effect of the pentapeptide H-Cys-Tyr-Ile-Gln-Asn-OH to act like melanocyte-stimulating hormone-releasing factor (MSH-RF) was studied. This peptide decreases at ng amounts the MSH content of the rat pituitary and increases plasma MSH concentration. This agent also stimulates the release of MSH in animals with eminence lesion, indicating a direct action of the pentapeptide on the gland.     

Durchflußfluorescenzcytophotometrie für ultraschnelle DNS-Messungen an großen Zellpopulationen

Zusammenfassung Ausgehend vom Leitz-Mikroskopphotometer MPV mit Auflicht-Anregung wird ein Durchflußfluorescenzcytophotometer beschrieben, das es gestattet, die relativen Feulgen-DNS-Mengen von bis zu 1000 Zellen pro Sekunde zu bestimmen. Die Meßwerte werden in einem Impulshöhenanalysator klassifiziert und gespeichert. Auf Abruf wird der Speicherinhalt analog als Histogramm ausgeschrieben oder digital als Zahlenfolge ausgedruckt.Das Vorgehen bei der Zellsuspensionsherstellung, Fixierung, Hydrolyse und Färbung mit dem Feulgen-Farbstoff Akriflavin wird dargelegt.Anwendungsbeispiele werden besprochen.

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Flow-through-cytophotometry for ultra-rapid DNA measurement of large cell populations

Summary A flow-through cytophotometer based upon the Leitz-microscope photometer (MPV) is described. The light source is a high pressure Xenon arc HBO 100 in an arrangement for epiillumination.The flow system is designed in such a way that each cell, after previous Feulgenstaining in aqueous suspension, has to pass through the focal plane of the objective. This is achieved by a self-constructed flow channel with a vertical fluid stram carrying the stained cells along the optical axis of the microscope at a flow rate of 100 to 1000 cells per sec. After passage through the focal plane with simultanneous registration of the highest fluorescence reading the cells are flushed off by a horizontal water current.The fluorescence light impulses emitted by the cells are classified and stored by an impulse height discriminator, from which they may be recalled either analogically as a histogram (DNA distribution pattern) or digitally as a series of numbers.In addition, the fluorescence impulses can be visualized at the screen of an oscillograph. The flow rate of the fluorochromized cells is determined by means of a counter unit.The steps of preparation of the cell suspension as well as fixation, hydrolysis and Feulgen-staining with acriflavine-Schiff of the suspended tissue cells is described in detail.The possibilities of application of the instrument as a cyto-morphometric approach to cytology and cytochemistry automation are discussed.

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Mit Unterstützung des Bundesministeriums für Jugend, Familie und Gesundheit.

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Zu besonderem Dank sind wir der Fa. Leitz, Wetzlar, verpflichtet. Sie stellte kostenlos das Mikroskopphotometer mit Lichtmeßeinrichtung zur Verfügung und ermöglichte uns die Überprüfung der Apparatur in ihren Laboratorien. Den wissenschaftlichen Mitarbeitern der Fa. Leitz, Herrn Ing. J. Rzeznik und Herrn Dipl. Phys. H. Wasmund, danken wir für ihre Beratung und die anregende Diskussion des Manuskriptes.Herrn Ing. H. Eipel, Fa. Elektronik Service, Frankfurt, sei für die Beratung bei Problemen der Impulsanalyse und Durchsicht des Manuskriptes gedankt.Ebenfalls danken wir Fräulein M. Schaden für die gewissenhafte und selbständige Durchführung der biologischen Versuche.     

TRPM8 Ion Channels Differentially Modulate Proliferation and Cell Cycle Distribution of Normal and Cancer Prostate Cells

Overexpression of the cation-permeable channel TRPM8 in prostate cancers might represent a novel opportunity for their treatment. Inhibitors of TRPM8 reduce the growth of prostate cancer cells. We have used two recently described and highly specific blockers, AMTB and JNJ41876666, and RNAi to determine the relevance of TRPM8 expression in the proliferation of non-tumor and tumor cells. Inhibition of the expression or function of the channel reduces proliferation rates and proliferative fraction in all tumor cells tested, but not of non-tumor prostate cells. We observed no consistent acceleration of growth after stimulation of the channel with menthol or icilin, indicating that basal TRPM8 expression is enough to sustain growth of prostate cancer cells.     

Occurrence of multiple-antibiotic-resistant enteric bacteria in domestic sewage and oxidation lagoons

The coliform bacterial population in the Grand Forks, N.Dak. sewage system was examined for multiple-antibiotic-resistant organisms over a 1-year period. Multiple-antibiotic-resistant coliforms were found to be common in the sewage, and their numbers remained fairly constant relative to the total coliform population throughout the year. Resistance to kanamycin, tetracycline, and ampicillin was found to be transferable at variable rates. Transfer rates were found to be temperature sensitive and were optimal at 35 degrees C. Although 75% of the multiple-antibiotic-resistant coliforms were capable of transferring resistance at some level, only 25% were capable of transferring resistance at rates greater than 10(-3) transconjugants per initial donor.     

Pyrroline-5-carboxylate reductase from Cucurbita cotyledons

Pyrroline-5-carboxylate reductase, which required reduced pyridine nucleotide and Δ′-pyrroline-5-carboxylate for proline synthesis, was isolated from pumpkin cotyledons. The enzyme was found in the soluble fraction and had a 4.5-fold greater activity with NADH than NADPH. The enzyme was inhibited by NH₂OH, NADP, ATP and slightly by proline. Glutathione or pyridoxal-5-phosphate had little effect on enzyme activity. The enzyme had a pH optimum between 7·0 and 7·6 and was not inhibited by high concentrations of NADH or Δ′-pyrroline-5-carboxylate.