Cerebral application of enkephalins

Summary Implantation of enkephalins A or B into the ventral thalamus or injection into the lateral ventricle of rats evoked only weak signs of stereotyped behavior, but did not cause gnawing.     

Quantification ofMycobacterium tuberculosis DNA using PCR and a simple dot blot-based DNA enzyme assay (DEA)

Conclusions Use of PCR for quantification of microorganisms has certain limitations. Methods currently under investigation, such as covalent binding of modified DNA onto the surface of microwells or coupling to magnetic beads with the aid of biotin-avidin, are hampered by problems concerning immobilization of DNA on a solid phase. Moreover, these strategies are laborious, including several washing steps and complicated detection systems (sandwich hybridization).We have developed an alternative method, exploiting the reliability of covalent DNA binding to positively charged nylon membranes enabling easy to handle direct hybridization. The method is adaptable for routine use in clinical laboratories. We have shown results of a quantitative assay to measure bacterial load of MTB. Quantification of MTB may have value in: (i) monitoring patients under anti-myobacterial therapy, and (ii) early in vitro drug susceptibility testing.     

Einfluss der Ionenstärke auf das Immunpräzipitationsvermögen von Amphibien-Antikörpern

Summary Precipitating antibodies of amphibia are more dependent on the ionicity of the buffer system than the well known rabbit antibodies.     

Differential healing periods of the acetic acid ulcer model in rats and cats

Zusammenfassung Methode zur experimentellen Erzeugung eines Magengeschwüres beim Tier, das weitgehend mit dem menschlichen Magengeschwür übereinstimmt.

---

---

This study was supported by the William H. Rorer Gastroenterology Research Fund.     

Interactions between the carbohydrate chains of hyaluronate and chondroitin sulphate

Hyaluronic acid-derivatised beads spontaneously agglutinate with chondroitin-sulphate-derivatised beads although neither bead type shows any self-agglutination. The interaction between hyaluronate and chondroitin sulphate is specific for these two glycosaminoglycans and appears to occur between their carbohydrate chains.     

Self-inhibiting extracellular proteins fromAspergillus oryzae

Zusammenfassung Mittels Ultrafiltration und Gelelektrophorese konnten 2 extrazellulare Protein-Fraktionen, Mol.-Gew. 27000–28000 daltons und 11000–12000 daltons, aus submersen Kulturen vonAspergillus oryzae gewonnen werden, welche Wachstumshemmung desselben Organismus bei Verabreichung zu Beginn der Kulturentwicklung verursachen

---

---

Technical assistance by Mrs.U. Stangl and Mr.L. Berzaczy is greatly appreciated.

---

These investigations are supported by the Austrian Fonds zur Förderung der wissenschaftlichen Forschung.     

Synthetic lethal screen identification of chemosensitizer loci in cancer cells

Abundant evidence suggests that a unifying principle governing the molecular pathology of cancer is the co-dependent aberrant regulation of core machinery driving proliferation and suppressing apoptosis. Anomalous proteins engaged in support of this tumorigenic regulatory environment most probably represent optimal intervention targets in a heterogeneous population of cancer cells. The advent of RNA-mediated interference (RNAi)-based functional genomics provides the opportunity to derive unbiased comprehensive collections of validated gene targets supporting critical biological systems outside the framework of preconceived notions of mechanistic relationships. We have combined a high-throughput cell-based one-well/one-gene screening platform with a genome-wide synthetic library of chemically synthesized small interfering RNAs for systematic interrogation of the molecular underpinnings of cancer cell chemoresponsiveness. NCI-H1155, a human non-small-cell lung cancer line, was employed in a paclitaxel-dependent synthetic lethal screen designed to identify gene targets that specifically reduce cell viability in the presence of otherwise sublethal concentrations of paclitaxel. Using a stringent objective statistical algorithm to reduce false discovery rates below 5%, we isolated a panel of 87 genes that represent major focal points of the autonomous response of cancer cells to the abrogation of microtubule dynamics. Here we show that several of these targets sensitize lung cancer cells to paclitaxel concentrations 1,000-fold lower than otherwise required for a significant response, and we identify mechanistic relationships between cancer-associated aberrant gene expression programmes and the basic cellular machinery required for robust mitotic progression.     

Rag mutations reveal robust alternative end joining

Mammalian cells repair DNA double-strand breaks (DSBs) through either homologous recombination or non-homologous end joining (NHEJ). V(D)J recombination, a cut-and-paste mechanism for generating diversity in antigen receptors, relies on NHEJ for repairing DSBs introduced by the Rag1-Rag2 protein complex. Animals lacking any of the seven known NHEJ factors are therefore immunodeficient. Nevertheless, DSB repair is not eliminated entirely in these animals: evidence of a third mechanism, 'alternative NHEJ', appears in the form of extremely rare V(D)J junctions and a higher rate of chromosomal translocations. The paucity of these V(D)J events has suggested that alternative NHEJ contributes little to a cell's overall repair capacity, being operative only (and inefficiently) when classical NHEJ fails. Here we find that removing certain portions of murine Rag proteins reveals robust alternative NHEJ activity in NHEJ-deficient cells and some alternative joining activity even in wild-type cells. We propose a two-tier model in which the Rag proteins collaborate with NHEJ factors to preserve genomic integrity during V(D)J recombination.     

The lakes of Titan

The surface of Saturn's haze-shrouded moon Titan has long been proposed to have oceans or lakes, on the basis of the stability of liquid methane at the surface. Initial visible and radar imaging failed to find any evidence of an ocean, although abundant evidence was found that flowing liquids have existed on the surface. Here we provide definitive evidence for the presence of lakes on the surface of Titan, obtained during the Cassini Radar flyby of Titan on 22 July 2006 (T16). The radar imaging polewards of 70 degrees north shows more than 75 circular to irregular radar-dark patches, in a region where liquid methane and ethane are expected to be abundant and stable on the surface. The radar-dark patches are interpreted as lakes on the basis of their very low radar reflectivity and morphological similarities to lakes, including associated channels and location in topographic depressions. Some of the lakes do not completely fill the depressions in which they lie, and apparently dry depressions are present. We interpret this to indicate that lakes are present in a number of states, including partly dry and liquid-filled. These northern-hemisphere lakes constitute the strongest evidence yet that a condensable-liquid hydrological cycle is active in Titan's surface and atmosphere, in which the lakes are filled through rainfall and/or intersection with the subsurface 'liquid methane' table.