Herpangina surveillance in Japan, 1982-1989. A report of the national epidemiological surveillance of infectious agents in Japan.

In Japan, herpangina cases increase every summer with an incidence peak in July. During the past eight years from January, 1982 to December, 1989, a total of 3,974 viruses from herpangina cases were reported from 47 participating laboratories, and coxsackie A (CA) viruses accounted for most of them, 3,055 (76.9%). The major types associated with herpangina were, in order of frequency, CA4, 10, 5, 6, 2 and 3, representing 87.2%-80.8% of total isolations reported for each respective type in this period. Eighty-four point four percent of the total virus isolations were from children at four years of age or younger. More than 80% of total CA virus isolations were from nasopharyngeal specimens and nearly 90% of the viruses were isolated in mice.     

Functional analysis of the regulatory region of the yeast phosphatidylserine synthase gene, PSS.

The upstream region of the PSS gene contains three positive cis-acting elements, upstream activation sequences 1 and 2 (UAS1 and UAS2) and a TATA box. The 5' end of UAS1 occurs between positions -239 and -209, and that of UAS2 is between positions -172 and -164. UAS2 contains 5'-TTCACATG-3' as a core sequence at positions -161 to -154. Mutational analysis revealed that this octamer is responsible for the control of PSS expression by inositol and choline. The TATA box is located at positions -112 to -108. In addition, PSS contains a negative cis-acting sequence between UAS2 and the TATA box.     

Poliovirus surveillance: isolation of polioviruses in Japan, 1980-1991. A report of the National Epidemiological Surveillance of Infectious Agents in Japan.

This report presents an overall distribution of poliovirus isolations in Japan, where poliomyelitis has been under control over two decades as a result of legal administration of two doses of the trivalent live oral poliovirus vaccine of the Sabin strains (OPV) to children under 48 months of age. During the past 12 years from 1980 through 1991, a total of 1,126 poliovirus isolations from humans and 268 isolations from sewage/river water were reported by respectively 49 and nine of the participating laboratories. Type 2 was most frequently isolated from children after administration of one dose of OPV, followed by type 1 and type 3. On the contrary, after the second dose of OPV, the rate of isolation of type 3 exceeded those of type 2 and type 1. Seasonal and age distribution of poliovirus isolations from both humans and sewage/river water paralleled the OPV vaccination schedule in Japan. One percent of the isolations were, however, from infants younger than the vaccination-scheduled ages and 5% were from children older than those ages, including one each from 15 and 16 years olds. The data indicate that the poliovirus has silently been disseminated from vaccinated children to others and the community, thus suggesting repeated transmission of the viruses. The fact that some elder children had poliovirus colonization in their alimentary tracts indicates a potential risk of infection of such a population when exposed to a wild virus and of becoming a source of transmission to others.     

Single crystals of bovine heart cytochrome c oxidase at fully oxidized resting, fully reduced and CO-bound fully reduced states are isomorphous with each other.

Fully reduced and CO-bound fully reduced forms of cytochrome c oxidase from beef heart muscle were crystallized in the presence of sodium ascorbate under N2 or CO atmosphere. Hexagonal bipyramidal and tetragonal crystals were obtained for both forms depending on buffer species. The hexagonal bipyramidal crystals, as large as 0.6 mm in the largest dimension, diffracted X-rays at 7 A resolution, showing an identical space group and cell dimension, P6(2) or P6(4) and a = b = 209 A, c = 283 A, respectively. These parameters coincide with those for crystals of the fully oxidized resting enzyme. This result suggests that a large conformational change, like a subunit arrangement, is not induced by the redox change and/or binding of CO (and possibly O2) to heme a3.     

Activation of Protein Kinase C Suppresses the γ-Aminobutyric AcidB Receptor-Mediated Inhibition of the Vesicular Release of Noradrenaline and Acetylcholine

Modulation of the gamma-aminobutyric acidB (GABAB) receptor-mediated response by protein kinase C (PKC) was examined with regard to inhibition by stimulation of the GABAB receptor of stimulation-evoked release of noradrenaline (NA) from slices of cerebellar cortex and of acetylcholine (ACh) from strips of ileum. 12-O-Tetradecanoylphorbol 13-acetate (TPA) potentiated the high K(+)-evoked Ca2+-dependent release of NA and ACh, but not the ouabain-evoked release, even in the presence of external Ca2+. The potentiating effect was antagonized by sphingosine, thereby suggesting that PKC participates in the exocytotic-vesicular release of neurotransmitters, but does not do so in case of a nonvesicular release. GABA inhibited the high K(+)-evoked release of NA and ACh, but not the ouabain-evoked Ca(2+)-independent release. The effect of GABA was mimicked by baclofen and was antagonized by phaclofen, thereby suggesting that stimulation of the GABAB receptor inhibits the vesicular but not the nonvesicular release of neurotransmitters. TPA suppressed the GABAB receptor-mediated inhibition of high K(+)-evoked release of NA and ACh. The effect of TPA was antagonized by sphingosine. These results indicate that stimulation of the GABAB receptor inhibits the stimulation-evoked Ca(2+)-dependent release of neurotransmitters and that activation of PKC suppresses the GABAB receptor-mediated response.     

Activation of mitogen-activated protein kinase and its activator by ras in intact cells and in a cell-free system.

Mitogen-activated protein (MAP) kinase is a serine/threonine kinase whose function is thought to be essential for the transduction of mitogenic signals. MAP kinase is activated by phosphorylation induced by a variety of extracellular stimuli, and its direct upstream activator has been identified. Using amphibian and mammalian systems, we show here that ras can activate MAP kinase and its activator. Injection of v-Ha-ras p21 into Xenopus immature oocytes activated both MAP kinase and maturation-promoting factor (MPF) activities. The activation of MAP kinase preceded that of MPF, demonstrating that ras activates MAP kinase in an MPF-independent pathway. Moreover, we found that the MAP kinase activator is also activated in ras-injected oocytes. Activation of MAP kinase and its activator occurred also when the v-Ki-ras gene was conditionally induced in rat fibroblastic 3Y1 cells. Furthermore, we observed that ras activated MAP kinase and its activator in a cell-free system prepared from Xenopus oocytes. Using an antibody against the Xenopus 45-kDa MAP kinase activator, we demonstrated that the 45-kDa activator molecule was activated by ras. These findings suggest that the MAP kinase activator/MAP kinase system may be the downstream components of ras signal transduction pathways.     

Unidirectional distribution of mosaicism in chimeric rats.

Experimental rat chimeras were produced by aggregation of eight-cell embryos from two inbred strains, ACI/Hkm and WKAH/Hkm, which differ from each other in their major histocompatibility complexes and coat colors, and their mosaicism was analyzed. The existence of the isozyme Es-1, a serum cholinesterase specifically produced by WKAH-derived cells, and the agouti coat color due to ACI cells, indicated that all of the rats analyzed were unequivocal chimeras. The proportion of ACI cells in the red blood cell populations of the chimeras varied from 45% to 98%, as determined with a fluorescence-activated cell sorter and a monoclonal antibody against class I (RT1) antigen. Digital analysis of the coat color revealed that the proportion of the ACI type of coat color ranged from 72% to 98% in these chimeric rats. Each phenotype expressed in the coat color was complex and varied in size. The ratios of red blood cells and the coat color inclined toward the ACI type of cell population. Conversely, the rate of the WKAH-cell-type population was less than 50%. A breeding test disclosed chimerism of germ cells in two chimeric rats, and there were more pups with agouti coats than with albino coats. Taken together, it was shown in most of the phenotypes analyzed that the ACI type of cells was predominant in all of the chimeric rats. We discuss the possible causes for this unbalanced distribution in the rats.     

Presence of histamine H2-receptors on human gastric carcinoma cell line MKN-45 and their increase by retinoic acid treatment.

Histamine dose-dependently stimulated cyclic AMP production in human gastric carcinoma cell line MKN-45, and this effect was inhibited by cimetidine but not by pyrilamine. Moreover, not only histamine but also cimetidine displaced the specific binding of [3H]tiotidine to these cells, whereas pyrilamine had no effect. On the other hand, pretreatment of MKN-45 cells with retinoic acid (RA) significantly enhanced histamine-induced increase of cyclic AMP production, although the cyclic AMP response to either forskolin or NaF was not affected. Finally, RA treatment increased the number of histamine receptor without altering its affinity. Thus, it appears that histamine H2-receptors are present on MKN-45 cells, and that RA treatment enhances the action of histamine on these cells by increasing the number of H2-receptors.