Ethanol and acetaldehyde do not increase the blood-brain and blood-retinal barrier permeability to sodium fluorescein

Summary No extravasation of sodium fluorescein from capillaries of the cerebral cortex and retina could be demonstrated in rats during severe nonlethal ethanol and/or acetaldehyde poisoning. The results do not exclude the possibility that repeated intoxications may gradually open the blood-brain and blood-retinal barriers, but do indicate the absence of an effect during acute intoxication.We are indebted to Prof. Arto Palkama for his kindness in placing the facilities of his laboratory at our disposal during his visit to USA, and also thank his personal technician Miss Ulla Jääskeläinen, who skilfully made the histological preparations.     

Ribosomal gene numbers in Microseridinae (Compositae: Cichorieae)

Summary 8 species of the subtribe Microseridinae contain between 1100 and 3400 genes for 25 and 18 S ribosomal RNA. The gene numbers seem to evolve by discrete steps. Their trend follows a general reduction in genome size during the evolution of the annual species ofMicroseris, but numbers remain high in one of them and inAgoseris grandiflora. 2 species ofPyrrhopappus differ by a duplication of the ribosomal gene numbers; 5 S ribosomal RNA genes in 4 species are repeated roughly 10,000 times.We thank Miss S. Werner, Miss A. Roth and Miss U. Krehan for help with some of the experiments. This paper is part of a project supported by grant Ba 536/1-5 from the Deutsche Forschungsgemeinschaft.     

Actinomycin-resistant antiviral activity associated with preparations containing chicken interferon

Summary Crude and purified preparations containing chicken interferon show a 2fold antiviral activity. One is inhibited by actinomycin and leads to total inhibition if interferon is added to cells before actinomycin, the other is insensitive to actinomycin and leads to partial inhibition if interferon is added simultaneously with or after actinomycin.Work supported by the Swiss National Foundation, grant 3.399.70.The authors wish to thank Miss E. Browse, Miss U. Kohler and Mr U. Rohrer for excellent technical assistance.     

Activity tests of alcohol dehydrogenases in wheat,rye and triticale

Summary The relative band staining intensities of ADH isoenzymes in wheat and triticale suggest alloploid genome interactions. Rye ADH is scarcely affected by anti-wheat-ADH. Despite the evolutionary divergence of their Adh genes, ADH monomers of wheat and rye form enzymatically active heterodimers in triticale.Dedicated to Prof. Dr V. Schwartz, Tübingen, on the occasion of his 70th birthday.I thank Miss Hiltrud Wambach and Miss Rita Lippert for technical assistance.     

At least two toxins are involved inEscherichia coli mastitis

Summary Culture filtrate ofEscherichia coli produces changes in the bovine udder identical to those seen in experimental infections with the same organism.E. coli endotoxin produces an acute inflammatory response but none of the cell damage induced by culture filtrate. It appears therefore that at least 2 toxins are involved in the disease.Acknowledgments. We are grateful to Mrs K. Wells, Miss H. Meads and Miss A. Ashford for technical assistance.     

Shape change of blood platelets induced by myelin basic protein

Summary Myelin basic protein (MBP) isolated from bovine spinal cord caused a marked shape change reaction of human blood platelets which was not accompanied by the release reaction and not inhibited by methysergide and spiroperidol. Only those basic proteins, including MBP, which had previously shown to exert neuronal depolarisation also induced the shape change reaction. Therefore, these findings may extend the use of platelets as neuronal models.Acknowledgment. We thank Miss B. Gieux and Miss M. Handschin for skilful technical assistance.     

A simplified method for reading hemagglutinations on a flat-bottom microtitration plate in the mouse H-2 assay

Summary Kaliss' method for determining hemagglutination titer of mouse alloantiserum was modified to a simpler form. It became possible to read the hemagglutination directly on a flat-bottom microtitration plate using an inverted type microscope. Sensitivity of the modified method was almost the same as that of the original one. This method seems to be useful especially for the larger scale assay of H-2 specificities.Contribution from the National Institute of Genetics. Supported in part by grants-in-aid (No. 111510, 111504, 112105) from the Ministry of Education, Culture and Science, Japan.Acknowledgments. The excellent technical assistance provided by Miss M. Kuranou, Mr K. Sakakibara and Miss M. Tsuyuki is gratefully acknowledged.     

Changes of the prostaglandin F23 metabolism in early human placenta

Summary The quantitative metabolism of PgF₂₄ was studied in different ages of early human placentae in vitro. The 15-OH-Pg-dehydrogenase became minimal at about the 9th week.This work was supported in part by WHO.The authors are indepted to Miss M. Pasztor, Mrs V. Palinkas and Miss G. Odrobina.     

Potassium transfer from brain to blood during sustained hyponatraemia in the newborn calf

Summary The effect of dilutional hyponatraemia on cerebral blood flow and oxygen consumption, and net transfer of K⁺ to the circulation from brain tissue drained by the sagittal sinus was investigated in anaesthetized calves. Cerebral blood flow decreased, and net transfer of K⁺ to the circulation increased during hyponatraemia.Acknowledgments. The expert assistance of Miss B.N. O'Connor, Miss D. McNaughton and Mr P.M.M. Bircham is gratefully acknowledged.     

Inhibition of cytokinesis in plant cells by 6-dimethylaminopurine and puromycin

Summary Binucleate cells are produced in garlic root tip cells with puromycin and with 6-dimethylaminopurine (6-DMAP), the purine component of puromycin. The possibility that the effect of puromycin on cytokinesis is due to 6-DMAP-which appears to be without short term effects on protein synthesis-is discussed.This work was supported by AI 031871 from the Centre National de la Recherche Scientifique (M-C.B.) and the University René Descartes (M-C.B. and F.L.), Paris.The authors would like to thank Miss G. Daouse and Miss M. Delage for excellent technical assistance.     

Determination of acetaldehyde in human blood

A method for the determination of acetaldehyde in human plasma by headspace gas chromatography is described. Chloralhydrate, an inhibitor of aldehyde dehydrogenase, is immediately added to the blood sample to prevent a rapid disappearance of acetaldehyde in the erythrocytes.     

Effects of acute intoxication with uranyl nitrate on bone formation

Summary The alteration of bone formation by an acute intoxication with uranyl nitrate is demonstrated by histologic and histometric methods. When compared with the controls, intoxicated animals showed a markedly lower density in healing sockets, while bone formation was reduced in healing sockets as well as in metaphyseal bone.Acknowledgments. This work was supported in part by grant No. 8461 d/82 of the National Research Council Argentina and by Research Contract No. 2816/R1/R2 of the International Atomic Energy Agency. The authors wish to acknowledge the valuble technical assistance of Miss Ofelia Chiesa and Miss Patricia Mandalunis.     

Reassociation of eukaryotic ribosomal subunits by a factor from rat ascites hepatoma cytosol

Summary Post-ribosomal supernatant extracts from Yoshida AH 130 ascites hepatoma cells promote the in vitro association of ribosomal subunits at low Mg²⁺ concentration. Comparable extracts from rat liver show, on the contrary, dissociation factor activity on ribosome monomers.The technical assistance of Miss M. Ravazzani and Miss L. Zingaretti is gratefully acknowledged.     

Serum cholinesterase: Function in lipoprotein metabolism

Summary Human serum beta-lipoproteins, isolated by percipitation with heparin-calcium mixture, showed cholinesterase activity. The enzyme activity was almost proportional to the lipoprotein concentration. Rats, treated with neostigmine, a cholinesterase inhibitor, showed a significant decrease in serum beta-lipoprotein and in the incorporation of H³-lysine into the lipoprotein compared to untreated controls. The decreased incorporation of H³-lysine into beta-lipoprotein was associated with increased labelling of alpha-lipoprotein. There was no significant difference in the labelling of pre-beta-lipoprotein. We propose that LDL is formed from VLDL in the presence of cholinesterase.We thank Dr C. J. Hutton for helpful discussions, Miss Patricia Fontaine for technical assistance, and Miss Patricia Candow and Mrs Barbara English for secretarial work. Supported by the Canadian Heart Foundation.     

A reliable method for obtaining longitudinal sections of sperms for electron microscopy

Summary A method is presented by which it is possible to obtain a high percentage of longitudinal sections through sperms for electron microscopy. The procedure is described in detail in order to permit easy reproduction.The technical help of Miss A. K. Baer is gratefully acknowledged.     

Acetaldehyde metabolism inDrosophila melanogaster

Summary A quantitative study on in vitro acetaldehyde degradation in homogenates fromDrosophila melanogaster files shows that aldehyde oxidase plays the major part in acetaldehyde detoxification. However, in a strain, celed AO null, because itsAldox locus produces no aldehyde-oxidase, acetaldehyde is also degradated by a still unknown mechanism. Alcoholdehydrogenase which is responsible for the dehydrogenation of ethanol in acetaldehyde, appears to catalyze the reversed reactions as wel, regenerating ethanol fromacetaldehyde.This work was supported in part by a grant from the FNRS of Belgium.     

The growth responses of hamster chondrocytes,dermal fibroblasts and embryo cells to whole blood serum and plasma-derived serum

Summary Autoradiographic studies with³H-thymidine demonstrated that the growth responses of hamster chondrocytes, dermal fibroblasts and embryo cells, respectively, differed in media containing whole blood serum (WBS) and plasmaderived serum (PDS). Dermal fibroblasts seemed to require a growth factor from platelets for growth, but chondrocytes did not. Embryo cells showed an intermediate pattern of growth response to this factor.This work was supported by a Grant-in-Aid for Cancer Research from the Ministry of Education, Science and Culture and the Ministry of Health and Welfare of Japan.We thank Miss M. Tanaka and Miss K. Kawana for technical assistance.     

Thiamine diphosphatase in rat small intestine

Summary TDPase is located mostly in the proximal portion of the small intestine and its activity, like that of ALPase, decreased markedly in thiamine deficiency. The decreased enzyme activities were restored after thiamine or vitamin D₃. Kinetic and other studies of the purified enzyme indicated the identity of the two enzymes.Acknowledgment. We thank Miss.T. Yagura and Miss.H. Kuroda for technical assistance.     

Ethanol metabolism inDrosophila melanogaster

Summary A quantitative study of the transformation of ethanol into acetaldehyde shows that, inDrosophila melanogaster, the mitochondrial ethanol oxidizing system is not very active but that the part played by catalase appears more important than expected. For a strain without alcoholdehydrogenase, ethanol is highly toxic. The presence of acetaldehyde in the culture medium is toxic for all the strains studied. But, since even a strain without any aldehydeoxidase lives normally, the metabolic production of acetaldehyde does not seem dangerous.     

The role of volume expansion,of prostaglandins and catecholamines in the development of acute renal failure

Summary A single injection either of isotonic or hypertonic saline solutions protected rats against acute renal failure (ARF) induced with glycerol. This protection was accompanied by increased urinary prostaglandin E (PGE) concentration. On the contrary, a single s.c. injection either of hypotonic saline or isotonic glucose solution, which did not increase urinary PGE concentration, or depletion of the endogenous catecholamines, using reserpine, did not protect the animals against acute renal failure.The authors wish to thank Miss Sylvie Bompis and Miss Ermione-Loukia Ghikas for their technical assistance and Mr Richard Irvine B.A. for his help with the English.