Involvement of peptide histidine isoleucine (PHI) in prolactin secretion induced by serotonin in rats

The possible role of hypothalamic peptide histidine isoleucine (PHI) in prolactin (PRL) secretion induced by serotoninergic mechanisms was investigated in male rats using a passive immunization technique. Intracerebroventricular injection of serotonin (5HT, 10 micrograms/rat) raised plasma PRL levels both in urethane-anesthetized rats and in conscious rats pretreated with normal rabbit serum (0.5 ml/rat, iv, 30 min before). Plasma PRL responses to 5HT were blunted in these animals when they were pretreated with rabbit antiserum specific for PHI (0.5 ml/rat, iv, 30 min before) (mean +/- SE peak plasma PRL: anesthetized rats 271.3 +/- 38.3 ng/ml vs 150.0 +/- 12.6 ng/ml, p less than 0.01, conscious rats 54.3 +/- 6.8 ng/ml vs 30.7 +/- 4.1 ng/ml, p less than 0.025). These results suggest that hypothalamic PHI is involved, at least in part, in PRL secretion induced by central serotoninergic stimulation in the rat.     

Parallel evolution of an alpine type ecomorph in a scorpionfly: Independent adaptation to high‐altitude environments in multiple mountain locations

Elucidation of the diversification process of organisms is one of the important tasks of biology. From the viewpoint of species diversity, insects are the most successful group among the diverse organisms on earth and evolutionary adaptation is one of the important factors driving this pattern. Evolutionary adaptation is one of the important factors in the diversification of insects. One of the representative examples of environmental adaptation in insects is the shortening and loss of wings in subalpine and alpine zones. In this study, we focused on the Japanese scorpionfly, Panorpodes paradoxus. In this species, individuals that inhabit mountainous regions and subalpine zones have long wings (the “general type”), and individuals that inhabit higher altitudinal ranges have short wings (the “alpine type”). We collected samples of all Japanese Panorpodes species and one Korean Panorpodes species, and conducted molecular phylogenetic analyses of the mtDNA COI (610 bp), COII (688 bp), and 16S rRNA (888 bp) and nuDNA EF1‐α (658 bp) and 28S rRNA (524 bp) regions in order to reveal the evolutionary history of the alpine type of P. paradoxus. As a result of molecular phylogenetic analyses, it was revealed that the alpine type of P. paradoxus was polyphyletic, and had evolved to become the alpine type at least twice independently at separate mountain locations. In addition, the result of divergence time estimation suggested that the alpine type is an “ecomorph”, having recently adapted to low temperature habitats following mountain uplift within the Japanese Archipelago and subsequent glacial‐interglacial cycles.     

Chemical modification of proteins: plotting of the remaining activity against the number of residues modified

In the study of chemical modification of proteins, it has been a common practice to plot the fractional remaining activity against the number of residues modified per protein molecule. Extrapolation of the initial, nearly linear portion of the curve to the axis giving numbers of residues has often been presumed to specify the actual number of critical groups modified, i.e., the stoichiometry of the modification and the inactivation reactions. However, this extrapolation method is not generally applicable (Horiike, K. & McCormick, D.B. (1979) J. Theor. Biol. 79, 403-414). This paper describes further examination of the underlying theoretical framework of the extrapolation method. The properties and features of the extrapolated values are considered and presented with numerical and graphical examples. And the theoretical conditions with which the extrapolated value gives the number of essential residues are derived.     

Distribution patterns and niche segregation of three closely related Japanese ephemerid mayflies: a re-examination of each species’ habitat from “megadata” held in the “National Census on River Environments”

Limnology - Changes in river environments due to elevation gradients have a great impact on living organisms. In particular, with respect to aquatic insects, it has been recognized that even in...     

Immunohistochemical interaction on antisera to HCG and its subunits with chorionic tissue of early gestation.

Immunohistochemical localization of hCG and its subunits in chorionic tissue of early gestation was carried out. Antibodies to purified hCG and its subunits were obtained by using these agents for immunization according to the small doses method. The antibody titers and specificities were examined by B/T and standard curves in homologous radioimmunoassay system. The tissue preparations were stained both by a direct and by an indirect method utilizing these antisera and observing the specimens under a fluorescent microscope. The results were as follows. 1) With the anti-hCG staining, fluorescence was observed in the syncytiotrophoblasts as reported previously while the cytotrophoblast were stained slightly. 2) with the anti-hCG-beta staining, the fluorescence was almost identical with that of hCG and showed a more distinct pattern. 3) with the anti-hCG-alpha staining, the fluorescence was found both in the syncytio- and cytotrophoblasts concurrently. Fluorescence of the latter cells was recognized as due to free alpha-subunit because cytotrophoblast was scarcely stained with anti-hCG and anti-hCG-beta.     

Carbohydrate structures of a normal counterpart of the carcinoembryonic antigen produced by colon epithelial cells of normal adults

Normal Faecal antigen-2 (NFA-2) and non-specific crossreactingantigen-2 (NCA-2), cross-reacting with anticarcinoembryonicantigen (CEA) antibodies, were found in normal human faececand meconium, respectively. Because NFA-2, NCA-2 and CEA areconsidered as the same gene products, NFA-2 and NCA-2 shouldbe normal counterparts of CEA produced by colon epithelial cellsof normal adults and fetuses, respectively. Comparison of sugarchain structures of these three antigens is indispensable inorder to unravel the stnaural alteration induced by malignanttransformation and development of colon epithelial cells. Thesugar chain structures of CEA (Yamashita,K. et al., Cancer Res.,47,3451–3459,1987) and NCA-2 (Yarnashita,K. et al., J.Bid Chem, 264,17873-17881,1989) were previously reported. Inthis paper, the structures of the oligosaccharides releasedfrom four NFA-2 samples by hydrazinolysis were studied by meansof lectin-affinity column chromatography, endo- and em-glycosidasedigestion, methylation analysis, hydrazinolys-nitrous acid deaminationand electrospray ionization mass spectrometry. NFA-2 contains24–27 mol of N-linked sugar chains/molecule, which issimilar to NCA-2 (27 mol) and CEA (24–27 mol). In contrastto CEA, which contains {small tilde} 8% high-mannose-type sugarchains all sugar chains of NFA-2 are mono- to tetra-antennarycomplex-type chains having four types of tri-mannosyl cores,with or without bisecting N-acetylglucosamine and fucose residues.The structures of their outer chain moieties comprise Galß1     

Establishment of a novel embryonic stem cell line by a modified procedure

To generate mutant mice, embryonic stem (ES) cells are used as a vehicle for introducing mutations. The establishment of ES cells is diffucult because it requires specific skills and it is time-consuming. We established a novel ES cell line derived from hybrid mice between C57BL/6 and DBA/2 using a modified method. To collect a large number of preimplantational embryos, we collected embryos at the 8-cell stage and cultured them to blastocysts, whereas the usual procedure of preparing the delayed blastocysts demands technical skills. To eliminate unnecessary female cells at an initial stage of inner cell mass culture, male clones were selected by polymerase chain reaction to detect the mouseSry gene. The established ES cell line efficiently contributed to the germ-line when injected into 8-cell embryos of ICR mice. This potency was maintained after manipulation throughout gene targeting.Abbreviations DMEM Dulbecco's modified Eagle's medium - FBS fetal bovine serum - FIAU 1-(2-deoxy-2-fluoro-beta-D-arabinofuranosyl)-5-iodouracil - LIF leukemia inhibitory factor - NEAA non-essential amino acids     

Lifetime list of publications by Hiroya Kawanabe

Hiroya Kawanabe produced more than 780 scientific papers, popular articles, governmental reports, chapters in books, edited or co-edited books, encyclopedia entries, and Japanese translations of books from 1952 until the compilation of this bibliography (Fall 1997). He was the sole or first author of 88% of these publications and shared authorship with 286 collaborators. Eighty-nine percent of his publications were in Japanese, others were in English, German, Chinese, Korean and Italian. His publications were devoted mainly to four topics: (1) ecology of freshwater fishes, especially the territorial behavior of ayu, Plecoglossus altivelis, and interspecific relationships and food segregation among fishes from 1956; (2) fish community ecology in Lake Tanganyika since 1979; (3) political articles on ecological research after 1991; and (4) museum activities after 1996. He also produced a number of newspaper articles (over 25% of total publications) addressing topics not only of science but literature, culture and philosophy. Kawanabe's articles in newspapers were produced mainly when he was the Director of the Center for Ecological Research of Kyoto University, and most of these articles concentrated on promoting the development of ecological research in Japan. The publications are arranged chronologically by year. The decision to add Japanese titles was based on the fact that their English translations, which follow in parentheses, are often too loose and imprecise. Unfortunately, our printers could not insert these titles in the Japanese characters so Roman transliterations had to be substituted.