Targeted disruption of the mouse transforming growth factor-beta 1 gene results in multifocal inflammatory disease.

Transforming growth factor-beta 1 (TGF-beta 1) is a multifunctional growth factor that has profound regulatory effects on many developmental and physiological processes. Disruption of the TGF-beta 1 gene by homologous recombination in murine embryonic stem cells enables mice to be generated that carry the disrupted allele. Animals homozygous for the mutated TGF-beta 1 allele show no gross developmental abnormalities, but about 20 days after birth they succumb to a wasting syndrome accompanied by a multifocal, mixed inflammatory cell response and tissue necrosis, leading to organ failure and death. TGF-beta 1-deficient mice may be valuable models for human immune and inflammatory disorders, including autoimmune diseases, transplant rejection and graft versus host reactions.     

Biomechanics: a pneumo-hydrostatic skeleton in land crabs

Like their aquatic counterparts, terrestrial crabs repeatedly shed their rigid exoskeleton during moulting. But in the case of land crabs, little water is available to provide a temporary hydrostatic skeleton before the new skeleton hardens, and air does not provide the buoyancy necessary to support the animal. Here we show that whenever its exoskeleton is shed, the blackback land crab Gecarcinus lateralis relies on an unconventional type of hydrostatic skeleton that uses both gas and liquid (a 'pneumo-hydrostat'). To our knowledge, this is the first experimental evidence for a locomotor skeleton that depends on a gas. It establishes a new category of hydrostatic skeletal support and possibly a critical adaptation to life on land for the Crustacea.     

Molecular orbital studies on the conformations of bicuculline and β-hydroxy GABA

Zusammenfassung Mit Hilfe der MO-Theorie wurden bevorzugte Konformationen für den GABA Agonisten -Hydroxy-GABA und den Antagonisten Bicucullin berechnet. In beiden Fällen ergeben sich fast gleiche Abstände zwischen der Ammoniumgruppe und dem Sauerstoffatom wie in der entsprechenden Struktur von GABA selbst.

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Supported by National Institutes of Health (US) Grant No. 19709.     

Molecular orbital studies on the conformation of γ-aminobutyric acid and muscimol

Zusammenfassung Mit Hilfe der Molecular Orbital Theorie werden die bevorzugten Konformationen für die-Aminobuttersäure und das strukturell verwandte Muscimol, die neurologisch bedeutsam sind, berechnet.

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Supported by National Institutes of Health (US) Grant No. GM-16312.     

Conformations of amino acids calculated from molecular orbital theory

Zusammenfassung Die Konformation einiger natürlicher Aminosäuren wird auf Grund einer erweiterten Hückel-Molekular-Orbital-Theorie berechnet.

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Recipient of a Public Health Service Research Career Development Award No. AM1159.