Studies on Microbial Ribonucleic Acid VI. Appearance of Methyl-deficient Transfer Ribonucleic Acid During Logarithmic Growth of Saccharomyces cerevisiae

Transfer ribonucleic acid (tRNA) that is deficient in methyl groups may be detected in logarithmically growing Saccharomyces cerevisiae. The amount of methyl-deficient tRNA is not constant throughout the logarithmic phase, but is maximal about one generation before the onset of the late growth phase. During this latter phase, the tRNA is fully methylated. The methyl-deficient tRNA is present during a period of high metabolic activity of the cell, characterized by increased RNA and protein content.     

Ammoniten mit Kieferapparat und Radula aus Lias-Geschieben

Jaws and radula have been found in two adult microconch specimens of the Liassic ammonite speciesEleganticeras elegantulum (Young & Bird, 1828) from glacial drift boulders near Hamburg. They are more similar to those of recent dibranchiates than ofNautilus, the radula having seven longitudinal rows of teeth instead of thirteen in recentNautilus. Since bothOwens classification of the cephalopods into Dibranchiata and Tetrabranchiata according to the number of gills (which cannot be observed in fossil cephalopods) andSchwarz’ division into Ecto- and Endocochlia according to the (assumed) relative position of body and shell are rather unfortunate, the radula is suggested as a sound basis of classification. It is acceptable to paleo- as well as to neozoologists. As yet, the known evidence is sufficient for a twofold division only: Class Cephalopoda Subclass Lateradulata: Nautiloidea Subclass Angusteradulata: Ammonoidea Coleoidea     

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Serum Auto Antibodies and Clinical/Pathological Features in German Shepherd Dogs with a Lupuslike Syndrome

This study presents 8 dogs of German Shepherd breed (6 males, 2 females, 2–5 years of age at onset of the disease) with a lupus like syndrome characterized by febrile polyarthritis, wasting, nephropathy, cutaneous lesions and high positive titres of ANA (antinuclear antibodies) of speckled type. The serum autoantibodies were further characterized by double immunodiffusion against ENA (extractable nuclear antigen), ELISA for Histone antibodies (Histon fraction H-24A and H-3S), indirect IF on rat-liver sections, non treated and RNase/DNase digested sections for DNP/RNP antibodies, and smears of a nemoflagellate C. luciliae for antibodies vs doubbel strained DNA, (dsDNA). Thus, the high ANA titres in these dogs represent varying types of autoantibodies against nucleoproteins of both DNA and RNA nature, associated histone antigens and non-histone antibodies (RNA and Sm) as well. Rheumatoid Factor titres in serum from these dogs were low or negative. Immunoglobulin deposits at dermo-epidermal junctions were demonstrated in some of the dogs with hyperkeratotic skin lesions. High concentration of serum-IgG was a constant finding in combination with anemia and in most cases leukopenia probably related to the chronic inflammatory process in these animals. Autoimmune hemolytic anemia (AIHA) or thrombocytopenia was not detected in these dogs.     

In Vivo Substitution of Choline for Sodium Evokes a Selective Osmoinsensitive Increase of Extracellular Taurine in the Rat Hippocampus

Recent investigations have demonstrated that taurine and phosphoethanolamine (PEA) are the amino acids most sensitive to microdialysis-perfusion with reduced concentrations of NaCl. The aim of the present work was to assess the importance of Na+ deficiency in evoking this response. Further, the previously described selectivity of replacement of Cl- with acetate with respect to amino acid release was reinvestigated. The hippocampus of urethane-anesthetized rats was dialyzed with Krebs-Ringer bicarbonate buffer, and amino acid concentrations of the perfusate were determined. Choline chloride was then stepwise substituted for NaCl, and, in some cases, mannitol (122 mM) was included in low sodium-containing media. In other experiments, NaCl was replaced with sodium acetate. The dialysate levels of taurine increased selectively in response to Na+ substitution. The elevation of taurine was linearly related to the increase in choline chloride, and maximal levels amounted to 335% of basal levels. The increase in extracellular taurine was not inhibited by perfusion with medium made hyperosmotic with mannitol. Replacement of Cl- with acetate stimulated the release of taurine to 652% of resting levels. In addition, PEA levels increased to 250% of control concentration. Other amino acids were unaffected by Cl- substitution. The results show that taurine transport is considerably more sensitive to Na+ depletion than glutamate transport, which also is known to be Na+ dependent. The taurine increase evoked by low Na+ is not caused by cellular swelling as it was unaffected by hyperosmolar medium. Finally, substitution of acetate for Cl- causes a specific elevation of extracellular taurine and PEA, possibly as a result of cytotoxic edema.     

Crystallographic data for soybean hydrophobic protein

The soybean hydrophobic protein belongs to a family of proteins that contains a number of storage and phospholipid binding proteins. Its function is not known, but its overall hydrophobic nature is typical of many membrane proteins of similar size. The molecular weight is 8.3 x 10(3), and it crystallizes in the space group P2(1)2(1)2(1), with a = 52.01 A, b = 43.50 A and c = 28.80 A. The crystals diffract to 1.8 A resolution, and are thus suitable for X-ray structural studies.