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.     

Differences in Fine Structures between Normal and RNA-induced Drosophila Pole Cells

Fine structures were compared between normal pole cells and those induced in embryos that had been uv-irradiated and then injected with intact polar plasm or with poly(A)⁺RNA extracted from cleavage embryos. Nuclei in nomal pole cells were spherical. In contrast, those in the induced pole cells were deformed to variable extents depending on materials injected with. Polar granules were smaller in pole cells induced by injection of poly(A)⁺RNA than in normal pole cells. The size of polar granules in polar-plasm-induced pole cells was intermediate between those in poly(A)⁺RNA-induced and normal pole cells. Small polar granules were observed in posterior cells of embryos uv-irradiated, nevertheless those cells were columnar and with identical morphology to somatic cells. Nuclear bodies showed a similar tendency in size differences as observed in polar granules in three types of pole cells observed.     

Restriction map and alpha-amylase activity variation among Drosophila mutation accumulation lines

The specific activities of alpha-amylase were measured for two sets of mutation accumulation lines, each set having originated from a different lethal-carrying second chromosome and SM1(Cy) chromosome and having been maintained by a balanced lethal system for about 300 generations. Significant variation was found to have accumulated among lines of both sets. Because of dysgenic crosses in the early generations of mutation accumulation, insertions or deletions of transposable elements in the Amy gene region were suspected of being the cause of this variation. In order to test this possibility, the structural changes in the 14 kb region of these chromosomes that includes the structural genes for alpha-amylase were investigated by restriction map analysis. We found that most part of the activity variation is due to replacements of a chromosomal region of SM1(Cy), including the structural genes for alpha-amylase, by the corresponding regions of the lethal chromosomes. One line also contained an insertion in this region but this line has an intermediate activity value. Thus, insertions of transposable elements into the Amy gene region were not found to be responsible for the new variation observed in alpha-amylase activity. If we remove those lines with structural changes from the analysis, the genetic variance of alpha-amylase specific activity among lines becomes non-significant in both sets of chromosomes.     

Dual loading of the fluorescent indicator fura-2 and 2,7-biscarboxyethyl-5(6)-carboxyfluorescein (BCECF) in isolated myocytes

Isolated rat heart myocytes were loaded with both the Ca2+ sensitive fluorescent probe fura-2/AM and the fluorescent pH indicator 2,7-biscarboxyethyl-5(6)-carboxyfluorescein (BCECF/AM). Changes in [Ca2+]i and pHi were measured simultaneously using digitized video fluorescence microscopy. In measurement of [Ca2+]i and pHi, the ratios of dual-loaded cells were not different from single-loaded cells. Using this method, [Ca2+]i and pHi in myocytes were 48 +/- 7 nM and 7.17 +/- 0.05. It is concluded that [Ca2+]i and pHi could be measured simultaneously in isolated myocyte using dual-loading of fura-2 and BCECF.     

Osmoelastic coupling in biological structures: a comprehensive thermodynamic analysis of the osmotic response of phospholipid vesicles and a reevaluation of the "dehydration force" theory

A comprehensive thermodynamic analysis of the osmotic response of phospholipid vesicles is presented, using the Gibbs free energy of a vesicle suspension including the elastic contribution of the bilayer membrane. The results indicate that, in addition to the hydrostatic pressure difference across the membrane and the interbilayer pressure due to electrostatic repulsion, the elastic pressure arising from the coupling between the osmotic stress and the elasticity of the membrane (osmoelastic coupling) should participate in the osmotic response of phospholipid vesicles. The data of Cowley et al. [Cowley, A. C., Fuller, N. L., Rand, R. P., & Parsegian, V. A. (1978) Biochemistry 17, 3163-3168] and of Parsegian et al. [Parsegian, V. A., Fuller, N., & Rand, R. P. (1979) Proc. Natl. Acad. Sci. U.S.A. 76, 2750-2754] on the osmotic shrinkage of multilayer vesicles are discussed in terms of the elastic pressure and the interbilayer pressure, and the proposed "dehydration force" theory is reevaluated from the viewpoint of the present analysis.     

Primary photoprocesses of phytochrome. Picosecond fluorescence kinetics of oat and pea phytochromes

The primary photoprocesses of etiolated oat and pea phytochromes (Pr forms) are diffusion-modulated by the microscopic viscosity within the chromophore pocket. The chromophore pocket is preferentially accessible to glycerol but not to Ficoll. Glycerol preferentially retarded the rate (rate constant ca. 1-2 X 10(10) s-1) of the initial reaction from the Qy excited state of phytochrome, whereas it increased the long fluorescence lifetime (nanosecond) component that can be attributed to either an emitting intermediate or to modified/conformationally heterogeneous phytochrome populations. The picosecond time-resolved fluorescence spectra of different phytochrome preparations (i.e., full-length vs 6/10-kDa NH2-terminus truncated forms of phytochromes from monocot and dicot plants) revealed no significant differences. The spectra in the picosecond time scale showed no spectral shifts, but at longer time scales of up to approximately 1.90 ns, significant blue spectral shifts were observed. The shifts were more in the truncated than in the full-length pea phytochrome. Comparison of the fluorescence decay data and the picosecond time-resolved fluorescence spectra suggests differences in conformational flexibility/heterogeneity among the preparations of the monocot vs dicot phytochromes and the full-length native vs the amino terminus truncated phytochromes.     

Purification and characterization of immunoglobulin production stimulating factor derived from human B lymphoblastoid HO-323 cells

An immunoglobulin (Ig) production stimulating factor (IPSF) for hybridomas was found in spent medium of the human B lymphoblastoid cell line, HO-323. The IPSF was purified by serial use of DEAE chromatography, ultrafiltration, gel filtration and HPLC-DEAE chromatography. Purified IPSF was estimated to be a 410 k macro molecule by gel filtration, and contained three types of isomers which were separated from each other by native polyacrylamide gel electrophoresis. All of the isomers were, however, assumed to have the same protein components by SDS polyacrylamide gel electrophoresis.The IPSF was effective for human-human and mouse-mouse hybridomas producing IgM, but not for IgG producers in the experimental condition used here. Human-human hybridoma HF10B4, cultured in IPSF-containing medium, produced 20 times more IgM than in IPSF-free medium under serum-free conditions. The IPSF showed very little proliferation stimulating activity on HF10B4 cells.     

Individual growth and smoltification of juvenile masu salmon, Oncorhynchus masou Brevoort, under rearing conditions

In a reared population of individually marked juvenile masu salmon, individual growth was monitored from the first autumn in 1983 to the following spring. The potential smolts were not significantly greater in mean fork length and body weight than the potential parr in late August of the first year, but they then grew faster until March of the second year. As a result, the potential smolts formed the upper mode of the bimodal length distribution after February. Especially in autumn (October and November) the specific growth rates of potential smolts were significantly greater than those of parr, and the bimodality in growth rate distribution was more distinct for males than females. These suggest that there are two groups having different growth rates in autumn of the first year and that sufficient growth in this period may play an important role in smoltification in the following spring.