Tritium analyses of groundwater from the Gort Lowland of Western Ireland

Zusammenfassung Grundwasserproben aus der Gort-Ebene (West-Irland) wurden auf Tritium-Gehalt analysiert und die Ergebnisse mit dem bereits bekannten Tritium-Einstrom dieser Gegend verglichen. Registrierungen des «World Precipitation Network» in Wien ergaben den Nachweis eines offenbar langsamen Durchflusses in das Grundwasser-Aquifer-System.

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Acknowledgments. The authors are indebted to the Nuclear Physics Division, Atomic Energy Research Establishment, Harwell (England) for tritium analyses and to Mr.B. R. Payne, Section of Isotope Hydrology, IAEA, Wien (Austria) for providing unpublished tritium data from Valentia for the period 1966 to 1971.     

Cadherin 23 is a component of the tip link in hair-cell stereocilia

Mechanoelectrical transduction, the conversion of mechanical force into electrochemical signals, underlies a range of sensory phenomena, including touch, hearing and balance. Hair cells of the vertebrate inner ear are specialized mechanosensors that transduce mechanical forces arising from sound waves and head movement to provide our senses of hearing and balance; however, the mechanotransduction channel of hair cells and the molecules that regulate channel activity have remained elusive. One molecule that might participate in mechanoelectrical transduction is cadherin 23 (CDH23), as mutations in its gene cause deafness and age-related hearing loss. Furthermore, CDH23 is large enough to be the tip link, the extracellular filament proposed to gate the mechanotransduction channel. Here we show that antibodies against CDH23 label the tip link, and that CDH23 has biochemical properties similar to those of the tip link. Moreover, CDH23 forms a complex with myosin-1c, the only known component of the mechanotransduction apparatus, suggesting that CDH23 and myosin-1c cooperate to regulate the activity of mechanically gated ion channels in hair cells.     

Pathways towards and away from Alzheimer's disease

Slowly but surely, Alzheimer's disease (AD) patients lose their memory and their cognitive abilities, and even their personalities may change dramatically. These changes are due to the progressive dysfunction and death of nerve cells that are responsible for the storage and processing of information. Although drugs can temporarily improve memory, at present there are no treatments that can stop or reverse the inexorable neurodegenerative process. But rapid progress towards understanding the cellular and molecular alterations that are responsible for the neuron's demise may soon help in developing effective preventative and therapeutic strategies.     

Physiology: does gut hormone PYY3-36 decrease food intake in rodents?

Batterham et al. report that the gut peptide hormone PYY3-36 decreases food intake and body-weight gain in rodents, a discovery that has been heralded as potentially offering a new therapy for obesity. However, we have been unable to replicate their results. Although the reasons for this discrepancy remain undetermined, an effective anti-obesity drug ultimately must produce its effects across a range of situations. The fact that the findings of Batterham et al. cannot easily be replicated calls into question the potential value of an anti-obesity approach that is based on administration of PYY3-36.     

Immunogenicity of a highly attenuated MVA smallpox vaccine and protection against monkeypox

The potential use of smallpox as a biological weapon has led to the production and stockpiling of smallpox vaccine and the immunization of some healthcare workers. Another public health goal is the licensing of a safer vaccine that could benefit the millions of people advised not to take the current one because they or their contacts have increased susceptibility to severe vaccine side effects. As vaccines can no longer be tested for their ability to prevent smallpox, licensing will necessarily include comparative immunogenicity and protection studies in non-human primates. Here we compare the highly attenuated modified vaccinia virus Ankara (MVA) with the licensed Dryvax vaccine in a monkey model. After two doses of MVA or one dose of MVA followed by Dryvax, antibody binding and neutralizing titres and T-cell responses were equivalent or higher than those induced by Dryvax alone. After challenge with monkeypox virus, unimmunized animals developed more than 500 pustular skin lesions and became gravely ill or died, whereas vaccinated animals were healthy and asymptomatic, except for a small number of transient skin lesions in animals immunized only with MVA.