Electroreception in the Turkistan catfish

Summary The Turkistan catfish,Glyptosternum reticulatum, has highly sensitive electroreceptors (threshold voltage gradient 1 V/cm) that detect a voltage drop across the skin. These electroreceptors were found to be sensitive to magnetic stimulation.     

Prostaglandin E2 increases mechanically evoked potentials in the peripheral nerve

Summary Subdermal injections of PGE₂ (5 g) in the rat foot lead to increases in the potentials evoked in sensory nerve branches by the mechanical stimulation of the skin. This sensitization of both A and C fibres complements the previously described hyperalgesic effects of prostaglandins of the E series.     

Occurrence of Hyp3-bradykinin in methanol extracts of the skin of the South African leptodactylid frogHeleophryne purcelli

Summary Methanol extracts of the skin of the South African amphibians belonging to the genusHeleophryne (H. purcelli purcelli, H. purcelli depressa, H. purcelli orientalis, H. natalensis) contain large amounts (20–500 g/g fresh tissue) of Hyp³-bradykinin.Supported by grants from the Consiglio Nazionale delle Ricerche, Italy, and from the Ministry of Education, Japan.     

Tumor necrosis factor-α inhibits collagen synthesis in human and rat granulation tissue fibroblasts

The purpose of the study was to examine the effects of tumor necrosis factor- (TNF-) on collagen gene expression in rat and human granulation tissue fibroblast cultures. The cells were exposed to 0.1, 1, 10, or 100 ng/ml of TNF-, and the rate of collagen synthesis was measured as synthesis of protein-bound³H-hydroxyproline. Total cellular RNA was isolated from fibroblasts, and measurements of specific cellular RNAs from fibroblasts were performed by Northern blot hybridizations using³²P-labeled cDNA probes. In cultures of rat granulation tissue fibroblasts TNF- decreased³H-hydroxyproline production to about 75% of that in controls and it also decreased pro1(I) and pro1(III) collagen mRNA levels, maximally to 33% and 23% of the control levels, respectively. In cultures of human granulation tissue fibroblasts a similar inhibiting effect in the production of collagen was seen. TNF- decreased the production of³H-hydroxyproline to 56% of the control value with a dose of 100 ng/ml also having an inhibiting effect on pro1(I) collagen mRNA levels of up to 43% of the control level. However, no effect was seen on pro1(III) collagen mRNA levels.     

Extrapyramidal pathways with monosynaptic effects upon primate α-motoneurons

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Effect of acute administration of Δ1-tetrahydrocannabinol on β-endorphin levels in plasma and brain tissue of the rat

Summary Acute treatment with ¹-tetrahydrocannabinol (¹-THC) elevated the concentration of -endorphin-like immunoreactivity (-ELIR) in plasma and in the hypothalamus, but not in the hippocampus of rats habituated to the injection procedure. These effects were not obtained with the psychotropically inert analog of (¹-THC), cannabidiol. In animals that had not been habituated to the injection procedure, placebo treatment induced a decrease in hippocampal -ELIR.The authors acknowledge the skillful technical assistance of Mrs Willeke Logtenberg.     

Sea urchin elongation factor 1δ (EF1δ) and evidence for cell cycle-directed localization changes of a sub-fraction of the protein at M phase

Eukaryotic elongation factor 1 (eEF1) is a translational multimolecular complex reported in higher eukaryotes to be a target of CDK1/cyclin B, the universal regulator of M phase, but whose role in the cell cycle remains to be determined. A specific polyclonal antibody was produced and used to characterize the delta subunit of sea urchin elongation factor 1 (SgEF1) in early embryos, a powerful model for investigating cell cycle regulation. The SgEF1 protein was present in unfertilized eggs as two isoforms of 35 and 37 kDa, issued from two different mRNAs. The two canonical eEF1 partners, eEF1 and eEF1, were shown to co-immunoprecipitate with the SgEF1 isoforms. Both isoforms were associated in a macromolecular complex, which resolved upon gel filtration chromatography at a molecular weight > 400 kDa, suggesting association with other yet unidentified partners. After fertilization, the amount as well as the ratio of both SgEF1 isoforms remained constant during the first cell division as judged by Western blotting. Immunofluorescence analysis showed that a pool of the protein concentrated as a ring at the embryo nuclear location around the period of nuclear envelope breakdown and was visualized later as two large spheres around the mitotic spindle poles. Thus, the eEF1 protein shows cell cycle-specific localization changes in sea urchin embryos.Received 27 May 2003; received after revision 1 July 2003; accepted 4 July 2003     

A new chalcone glucoside and cernuoside from the flowers ofAcacia dealbata

Summary A new chalcone glucoside has been isolated from the flowers ofAcacia dealbata and shown to be 4,2,4,6-tetrahydroxy-3-methoxychalcone 2-O--D-glucoside (1) by chemical degradations and spectroscopic methods. Cernuoside (4,6,3,4-tetrahydroxyaurone 4-O--D-glucoside), (2) has also been found in this plant material.Acknowledgments. The author thanks Prof. H. Wagner, Institut für pharmazeutische Arzneimittellehre der Universität München, for a sample of homoeriodictyol, and Prof. J.B. Harborne, University of Reading, for a sample of aureusidin.     

Über die «absoluten» Bewegungen der Milchstrasse und der nächsten Spiralnebel

Summary (1) The milky way is moving absolutely (relative to the light-ether) with a velocity of at least 600 km/s in the direction of the absolute movement of the earth (A=78°,D=+40°).(2) The point of symmetry of the absolute velocities of the spirals is situated about 1,120,000 parsec from the milky way in the direction of the antapex of his absolute movement, and it has taken 1·83 milliards of years for the milky way to cross this distance.(3) Probably the next spirals are forming with the milky way as a center a group with a common parallel movement like that one of the milky way.     

Presence of specific binding sites for [3H]sarcophytol-A in cultured human skin fibroblasts

Summary The presence of specific binding sites for [³H]sarcophytol-A in human skin fibroblasts was examined using biochemical and morphological methods. The displacement studies clearly revealed that high (K_D=31.0 nM) and low (K_D=6.05 M) affinity sites were present in the intact cells. Moreover, autoradiographic studies using light microscopy revealed that the specific binding sites may exist in boththe cytoplasm and the nuclei.     

The use of 5-fluorocytosine and ketoconazole in the culture of the erythrocytic stages ofPlasmodium falciparum and some tumor cell lines

Summary In vitro culture systems are often contaminated by bacteria and fungi. It is therefore often necessary to supplement culture media with agents such as penicillin/streptomycin, gentamycin or amphotericin B. The latter cannot be used in the in vitro culture of erythrocytic stages ofP. falciparum, and thus anti-fungal agents have not been regularly used in this system. We describe the prophylactic use of 5-fluorocytosine (5-FC) and ketoconazole (KTZ) in tissue cultures at concentrations up to 300 and 10 g/ml respectively which have no effect on the growth ofP. falciparum (FCR-3 strain). A melanoma cell line (C32) and a line of uterine carcinoma (C41) were also unaffected by similar concentrations of 5-FC and KTZ. When dissolved in complete culture medium (RPMI 1640) with 10% human plasma, the minimum inhibitory concentration of 5-FC for a susceptible strain ofCandida remained below 2 g/ml. These experiments suggest that 5-FC (at 50 g/ml) alone or in combination with KTZ (at 1 g/ml) is a useful addition to the armamentarium of antimicrobials available to the tissue culture biologist for a variety of cell culture systems.     

An epoxidation byCorynebacterium simplex

Zusammenfassung Während unserer Untersuchungen über die mikrobiologische Dehydrierung verschiedener 16-Methylsteroide durch Bakterienkulturen vonCorynebacterium simplex, wurde eine neue Art von Umwandlung beobachtet. Von 16-Methyl-9(11)-pregnen-17, 21-diol-3, 20-dion-21-acetat ausgehend, gelang es aus den Kulturfiltraten 16-Methyl-1, 4-pregnadien-9, 11-epoxy-17, 21-diol-3, 20-dion zu isolieren. In einigen Fällen wurde auch das4-Derivat dieser Verbindung als Nebenprodukt erhalten.     

Defensive steroids from a carrion beetle (Silpha americana)

Summary The defensive anal effluent discharged bySilpha americana in response to disturbance contains a mixture of steroids stemming from a glandular annex of the rectum. The compounds have been characterized as 15-hydroxyprogesterone (1, principal component), 5-pregnan-15-ol-3, 20-dione (2), 5-pregnan-3, 15-diol-20-one (3), 5-pregnan-7, 15-diol-3,20-dione (4), 5-pregnan-3, 7, 15-triol-20-one (5), 5-pregnan-16-ol-3,20-dione (6), and 5-pregnan-3, 16-diol-20-one (7), none previously found in insects. Bioassays with jumping spiders showed compounds1 and6 to be feeding deterrents at the 1 g level.Paper No. 78 of the series: Defense Mechanisms of Arthropods. Study supported by NIH (Grants AI-02908, AI-12020). We thank Maura Malarcher and Maria Eisner for excellent technical help, and the Squibb Institute of Medical Research for samples of authentic reference compounds.     

Bovine microvascular endothelial cells of separate morphology differ in growth and response to the action of interferon-γ

Five cell types recently isolated from the bovine corpus luteum differed in their epithelioid morphology and their cytoskeleton, but shared common criteria of microvascular endothelial cells^1,2. To give strong evidence for the separate entity, the growth rate of the 5 phenotypically different cells was studied. They were seeded at low density on day 0. Most of these cells were treated with 200 to 1000 U recombinant bovine interferon- (IFN-) for 3 days. The untreated remainder served as controls. Cell counts were made for all cultures on days 4, 7, 10 and 13. morphology: 13 d after treatment with IFN- senescent cells as well as intact cells occurred in cultures of cell types 1 to 4. Cultures of cell type 5 were apparently unchanged and resembled their untreated counterparts. Desminpositive cells in cultures of cell type 2 developed cell processes. Growth rate: In the absence of IFN-, the growth rate was high for cell types 3 and 4, moderate for cell type 1, and low for cell types 2 and 5. The presence of IFN- caused anti-proliferative effects. These were higher for cell types 3 and 4 than for cell types 1 and 2. IFN- could be cytotoxic on cell type 3. In contrast, the cytokine tended to support the cell growth of cell type 5. These findings substantiate the postulate that endothelial cells exhibiting separate morphology in culture also function differently.     

α-andβ-activity of O-methylated derivatives of norepinephrine and epinephrine

Summary Metanephrine, iso-metanephrine, normetanephrine and isonormetanephrine were tested for - and -activity on various tissues obtained from rats, guinea-pigs and cats. It was found that methylation of the hydroxyl groups of norepinephrine or epinephrine in either the 3-or 4-position markedly reduces or abolishes -and -activity with the exception of the nictitating membrane of the cat. This receptor seems to show a tissue difference.Acknowledgment. W. H. V. would like to thank the Federal Republik of Germany for the U. S. Senior Scientist Award which enabled him to work at the Department of Pharmacology, University of Mainz, and to conduct part of this work. W. H. V. would also like to thank Prof. Dr E. Muscholl, Mainz, for his hospitality, help and advice during this stay.     

The identification of εN-(β-aspartyl)-l-lysine in native and heated keratin

Zusammenfassung Chromatographisch (Ionenaustausch, Papierchromatographie, Dünnschichtchromatographie und Hochspannungselektrophorese) wird nach enzymatischer Hydrolyse von nativem und denaturiertem Wolle-Keratin (-Glutamyl)-lysin und (-Aspartyl)-lysin identifiziert und so die in Proteinen postulierte anomale Peptidverknüpfung nachgewiesen.

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Acknowledgments. The authors would like to thank Dr.B. Milligan for a gift of N(-aspartyl) lysine. They would also like to thank the Wool Industries Research Association for permission to publish this work and for a Post-Doctoral Fellowship to one of them (M.S.O.).     

Failure of somatostatin to influence experimental tumor cell growth in vivo and in vitro

Summary The influence of somatostatin on tumor cell growth was studied in vivo in mice (sarcoma 180 ascites tumor and Lewis lung tumor) and in vitro on nontransformed and polyoma-transformed cell lines. 4 or 20 g/100 g of cyclic somatostatin and 4 g/100 g of linear protamin Zn-bound somatostatin were injected s.c. twice daily in the in vivo study. Cyclic somatostatin (1, 4 or 10 g/ml) was added twice daily to the cell cultures. Somatostatin administration influenced neither the survival of animals nor the growth rate of cultured cell lines. *** DIRECT SUPPORT *** A2025117 00011     

Physicochemical studies of indocyanine green (ICG): absorbance/concentration relationship,pH tolerance and assay precision in various solvents

Summary Indocyanine green (ICG) obeyed the Beer-Lambert law within the concentration range 1.25 g/ml–10.0g/ml in distilled water, methanol, dimethylformamide (DMF), 1.2-propanediol and aqueous buffers (pH 9.0), but only up to 7.5 g/ml in human bile and 0.5% human albumin, and only to 5.0 g/ml in human duodenal fluid. ICG was rapidly (<1 h) decomposed to a colorless derivative at pH<5 and >11, but remained relatively stable for 48 h at pH 8–10. ICG is an indicator and a weak acid with a pKa of 3.27. In bile stabilized with 25% methanol, the precision of the method (CV) is 5% and the accuracy is 106–127%.     

2-Amino-6-[(1'R,2'S)-1',2'-dihydroxypropyl]-3-methyl-pterin-4-one,a biologically active metabolite from the anthozoanAstroides calycularis Pallas

Summary 2-Amino-6-[(1'R,2'S)-1',2'-dihydroxypropyl]-3-methyl-pterin-4-one (1) has been isolated from the marine anthozoanAstroides calycularis; its structure was illustrated by spectral analyses including 2D-NMR and by partial synthesis.1 appears to possess cell-growth inhibiting activity.29 December 1986Work supported by C.N.R. (Progetto Finalizzato Chimica Fine e Secondaria) and by Ministero Pubblica Istruzione Italy. — Acknowledgments. Mass spectral data were provided by Servizio di Spettrometria di massa del C.N.R. e dell'Università di Napoli. The assistance of the staff is gratefully appreciated. Finally we would like to thank Prof. C. Pietropaolo for supplying chick embryo fibroblasts.     

Human MutY: gene structure,protein functions and interactions,and role in carcinogenesis

Faithful maintenance of the genome is crucial to the individual and the species. Oxidative DNA damage, such as 8-oxo-7,8-dihydroguanine (8-oxoG), poses a major threat to genomic integrity. 8-OxoG can mispair with 2-deoxycytidine 5-triphosphate or with 2-deoxyadenosine triphosphate during DNA replication, forming C8-oxoG and A8-oxoG mispairs. Human MutY is responsible for recognition and removal of the inappropriately inserted adenine in an A8-oxoG mispair. If unrepaired, the A8-oxoG mispairs can result in deleterious C:G to A:T transversions. Human MutY functions in a postreplication repair pathway and is targeted to the newly synthesized daughter strand of DNA for removal of the adenine base. The human MutY protein is targeted to both the mitochondria and the nucleus and associates with the proliferating cell nuclear antigen, apurinic/ apyrimidinic endonuclease 1, replication protein A and mutS homolog 6 proteins. Mutations in the human MutY gene and defective activity of the human MutY protein have been detected in cancer. A direct correlation between defective A8-oxoG repair and increased levels of genomic 8-oxoG has now been established.Received 10 February 2003; received after revision 7 April 2003; accepted 14 April 2003