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.     

Hydrops fetalis caused by intrauterine human parvovirus infection

During a large outbreak of erythema infectiosum in 1987 in Toyama prefecture, Japan, a 32-year-old woman acquired a mild rash on her arms and legs at 18 weeks of gestation. At 26 weeks and 4 days of gestation, the fetus died by hydrops fetalis and pregnancy was terminated. Histological studies of the fetus revealed degeneration of erythroblastic cells in the liver and bone marrow. Extensive extramedullary hematopoiesis and hemosiderin deposits were observed in the liver. Antibody response to human parvovirus B19 virus was demonstrated in maternal sera by ELISA. Furthermore, dot hybridization with the molecularly cloned DNA probe revealed the presence of human parvovirus DNA sequence in the fetal liver, spleen, lung, kidney and placenta. This report describes the first case in Japan of hydrops fetalis caused by human parvovirus B19 infection.     

The early expression of immunoreactivity for calmodulin in the nervous system of mouse embryos

Summary Calmodulin (CaM) is a major calcium-binding protein in the brain, where its immunoreactivity is mainly localized in the neurons. In this study, ontogenical changes in the distribution of CaM in the nervous system of mouse embryos were investigated immunohistochemically using a specific antibody against CaM and an indirect immunoenzyme method. Immunoreactive staining was first observed in the marginal layer of the cranial neural tube after 9.5 days of gestation; thereafter, the amount of stained structures increased rapidly. Particularly intense staining was observed in the long neuronal processes extending from or into the brain and spinal cord primordia. Intense immunostaining was also observed in the optic nerve layer of early retinae from 12.5 days of gestation. The appearance of CaM immunoreactivity is thus an early event during neuronal differentiation, apparently concominant with the initiation of axon extension and the appearance of neurofilament proteins.     

Revision of the theory of phototropism in plants: a new interpretation of a classical experiment

Went's classical experiment on the diffusion of auxin activity from unilaterally illuminated oat coleoptile tips (Went 1928), was repeated as precisely as possible. In agreement with Went's data with theAvena curvature assay, the agar blocks from the illuminated side of oat (Avena sativa L. cv. Victory) coleoptile tips had, on an average, 38% of the auxin activity of those from the shaded side. However, determination of the absolute amounts of indole-3-acetic acid (IAA) in the agar blocks, using a physicochemical assay following purification, showed that the IAA was evenly distributed in the blocks from the illuminated and shaded sides. In the blocks from the shaded and dark-control halves the amounts of IAA were 2.5 times higher than the auxin activity measured by theAvena curvature test, and in those from the illuminated half even 7 times higher. Chromatography of the diffusates prior to theAvena curvature test demonstrated that the amounts of two growth inhibitors, especially of the more polar one, were significantly higher in the agar blocks from the illuminated side than in those from the shaded side and the dark control. These results show that the basic experiment from which the Cholodny-Went theory was derived, does not justify this theory. The data rather indicate that phototropism is caused by the light-induced, local accumulation of growth inhibitors against a background of even auxin distribution, the diffusion of auxin being unaffected.Abbreviation IAA indole-3-acetic acid     

Reevaluation of the amino acid sequence of porcine follitropin

We have reevaluated the sequence of porcine follicle-stimulating hormone (pFSH) with more recent protein-sequencing methodology. This has led to revision of the earlier proposed sequence. As with almost all reported gonadotropin -subunits, NH₂-terminal heterogeneity was found in the porcine FSH -subunit (FSH), starting with residue Phe (1), Asp (3), Gly (4), or Thr (7). In the -subunit, there were found to be at least two molecular species, starting with residue Asn (1) (minor 20%) or Cys (3) (major 80%) as NH₂-terminal and ending at residue Glu (108) as COOH-terminal. The net effect of the present revisions is to increase the homology of pFSH with other reported follitropin sequences. Apparent differences in the half-cystine placements in a previous proposal for pFSH compared with other species of FSH are no longer tenable. The half-cystine placements thus remain a constant structural feature throughout the gonadotropin hormones (choriogonadotropin, follitropin, and lutropin).     

The asymptotic transectional/circumferential homogeneity of the solutions of reaction-diffusion systems in/on cylinder-like domains

It is often reported that an animal with spotty coat markings on its body has a tail with stripe-shaped pattern. In other various biological and chemical phenomena in/on cylinder-like domains, longitudinally periodic band patterns are observed much more often than the other non-uniform patterns. This paper mathematically explains these observations by proving that, in/on a long and narrow cylinder-like domain, any solution of reaction-diffusion system asymptotically loses its spatial dependence in the transectional/circumferential direction.