Seroepidemiology of hepatitis A virus in Japan

A seroepidemiologic study to detect class-specific antibody against hepatitis A virus (HAV) was made with 831 randomly collected sera (415 in 1973 and 416 in 1984) from healthy Japanese. Competitive-inhibition, IgG, IgA, and IgM anti-HAV enzyme-linked immunosorbent assays (ELISA) were used. Both collections showed a low prevalence of IgG anti-HAV in young age groups and it increased rapidly at middle age and plateued at greater than or equal to 94% prevalence in the older age groups. However, two age groups spanning ages 25-34 demonstrated statistically lower IgG anti-HAV age prevalences in 1984 vs 1973 (P less than 0.001), with an average 10-year prevalence shift. These data suggest that there has been no significant level of HAV infection to alter antibody prevalences in Japan from 1973 to 1984. The markedly decreased incidence of HAV infection in Japan has created a presently large and growing population of HAV susceptibles.     

Stereoselective total synthesis of ceramide Di-, Tri- and tetrahexosides of wheat flour

The first total synthesis of glycosphingolipids isolated from wheat flour has been achieved in a regio- and stereo-controlled manner.Abbreviations THF tetrahydrofuran - DMF dimethylformamide Part 53 in the series Synthetic Studies on Cell Surface Glycans     

Comparison of in vitro susceptibilities of Rickettsia prowazekii, R. rickettsii, R. sibirica and R. tsutsugamushi to antimicrobial agents

The in vitro activities of 16 antimicrobial agents against Rickettsia prowazekii (Breinl strain), R. rickettsii (Bitterroot strain), R. sibirica (ATCC No. VR151) and R. tsutsugamushi (Gilliam, Karp, Kato, Shimokoshi, Kawasaki and Kuroki strains) were determined by the cell culture method. Tetracycline, demethylchlortetracycline, doxycycline, minocycline, chloramphenicol, kitasamycin and rifampicin were generally effective (MIC, 0.005-0.78 micrograms/ml) to all strains tested. Quinolones such as norfloxacin, ciprofloxacin and ofloxacin were moderately active, but they were less active against R. tsutsugamushi than other rickettsial species. Penicillins and cephems showed low activity against most of the strains tested, but high concentrations of benzylpenicillin (MIC, 25-50 micrograms/ml) inhibited R. prowazekii, R. rickettsii and R. sibirica. These findings may be applicable for differentiation of species of genus Rickettsia.     

Quantitative fluorescence microscopy on dynamic changes of plastid nucleoids during wheat development

Summary Dynamic change of plastid nucleoids (pt nucleoids) was followed by fluorescence microscopy after staining with 46-diamidino-2-phenyl indole (DAPI). The fluorescence image was quantified with a supersensitive photonic microscope system based on photon counting and image analysis. The results showed that small pt nucleoids located in the center of proplastids in the dry seed increased in size after imbibition and formed highly organized ring structures in the dark, which divided into ca. 10 pieces within 3 days. Corresponding to this morphological change, DNA content of a plastid multiplied 7.5 fold. Total increase in DNA content of pt nucleoids per cell was 34 times as that of dry seed, as plastid multiplied 4.6 times in the average during this period. Upon light illumination small pt nucleoids having basic genome size were separated from divided pt nucleoids, suggesting a relationship with the formation of thylakoid system. The significance of the procedure established in this study is discussed in analysing the dynamic changes of intracellular small genomes.On leave from Department of Biology, Faculty of Science, Nagoya University, Furocho, Chikusaku, Nagoya 464, Japan.     

Proteolytic Activity against Model Peptides of the Cell Wall Lytic Enzyme from Chlamydomonas

A cell wall lytic enzyme (gamete wall-autolysin) from Chlamydomonasreinhardtii specifically cleaved several synthetic model peptides,-neo-endorphin, dynorphin (1–13), neurotensin and mastoparan,at the peptide bonds between consecutive hydrophobic amino-acidresidues. The cleavage was not significantly affected by high-saltconditions which are known to inhibit digestion of the cellwall. (Received December 14, 1989; Accepted April 5, 1990)     

Negative-ion fast atom bombardment and electrospray ionization tandem mass spectrometry for characterization of sulfated and sialyl Lewis-type glycosphingolipids

Structural characterization of sulfated and sialyl Lewis (Le)-type glycosphingolipids performed by fast atom bombardment (FAB) and electrospray ionization (ESI) mass spectrometry is described. Both FAB and ESI collision-induced dissociation tandem mass spectrometry (CID-MS/MS) of acidic glycosphingolipids allowed identification of the sulfated or sialyl sugar, and provided information on the saccharide chain sequence. The negative-ion tandem FABMS of sulfated Le-type glycosphingolipids having the non-reducing end trisaccharide ion as the precursor can be used to differentiate the Le^a- and Le^X-type oligosaccharides. The ESI CID-MS/MS of multiple-charged ions provided even more detailed structural information, and some of the useful daughter ions appeared with higherm/z values than the precusor because of a lower charge-state. These methodologies can be applied to the structural analyses of glycoconjugates with much larger molecular masses and higher polarity, such as the poly-sulfated and sialyl analogues.Abbreviations CID collision-induced dissociation - ESI electrospray ionization - FABMS fast atom bombardment mass spectrometry - Fuc fucose - Gal galactose - GlcNAc N-acetylglucosamine - Le Lewis - Le^a Lewis^a - Le^X Lewis^X - MS/MS mass spectrometry/mass spectrometry - NeuAc N-acetylneuraminic acid - 3-SO₄-Le^a 3-sulfated Le^a pentaosyl ceramide - 3-SO₄-Le^X 3-sulfated Le^X pentaosyl ceramide - 2,3-SO₄-Le^X 2,3-disulfated Le^X pentaosyl ceramide - 3-S-Le^a 3-sialyl Le^a pentaosyl ceramide - 3-S-Le^x 3-sialyl Le^X heptaosyl ceramide - 3-S-Le^X-Le^X 3-sialyl-Le^x-Le^x octaosyl ceramide.