Distribution and subcellular localization of a growth inhibitory factor in hamster liver and its intracellular partner(s)

The subcellular, intralobular distributions and intracellular partner(s) of a factor which inhibits the proliferation of cell growth (Hashimoto C. et al. (1994) Biochim. Biophys. Acta 1221, 107-117) were determined in hamster livers, using a combination of immunological and biochemical techniques. The IgG fraction from an antiserum raised against the growth inhibitory factor with 37 kDa was shown to be highly specific for the antigen. The nuclear and cytosolic fractions demonstrated inhibitory effects on cell growth and Western blot analysis revealed that both fractions contained the immunoreactive 37 kDa protein with the anti-inhibitory factor IgG but microsomal and mitochondrial fractions did not. The nuclear and cytoplasmic localization of the inhibitory factor were further confirmed by immunochemical staining mediated through the immune IgG and an avidin-biotinylated horseradish peroxidase complex, the parenchymal liver cells were clearly stained, but endothelial and connective tissue cells were not. Although some staining was evident throughout the liver parenchyma, the hepatocytes with most intensively stained nuclei were located in the periportal region. In the liver from hamsters 6 days old or the regenerating hamster livers 3 days after partial hepatectomy, the staining intensity was low and the number of hepatocytes with the inhibitory factor positive nuclei was very few compared with the adult hamster livers. In primary cultures of the isolated hepatocytes from adult hamster the inhibitory factor disappeared from nuclei after incubation for 24-48 h. The extracts of hepatic nuclei from adult hamsters were immunoprecipitated with either the anti-growth inhibitory factor IgG or a monoclonal antibody to the RM protein. The growth inhibitory factor and the RB protein coprecipitated in each case, implying that the proteins were complexed with each other in the nuclei. The RB protein family is composed of two sets of species, an un- or underphosphorylated species and a hyperphosphorylated one. It was suggested that the factor bound preferentially to the un- or underphosphorylated member of the family.     

Characterization of the interaction between synapsin I and calspectin (brain spectrin or fodrin)

We characterized the properties of the interaction between synapsin I and calspectin using purified proteins. The binding assay in the native state using antibodies specific to the tail region of synapsin I revealed that the binding is a high affinity with Kd of 9 nM, which is almost comparable to that of synapsin I to synaptic vesicles and to F-actin. We demonstrated that the head-middle region of synapsin I binds the NH2-terminal domain of beta subunit of calspectin, which also contains an actin binding site. Furthermore, the interaction was significantly inhibited by phosphorylation of synapsin I by cAMP-dependent protein kinase or by Ca2+, calmodulin-dependent protein kinase II. These properties of the interaction between synapsin I and calspectin may help understanding of its modulatory roles in neurotransmitter release.     

Characteristics of permeation and separation of dimethyl acrylamide-methyl methacrylate random and graft copolymer membranes for a benzene/cyclohexane mixture

When a benzene/cyclohexane mixture was permeated through poly(dimethyl acrylamide-random-methyl methacrylate) (DMAA-r-MMA) and poly(dimethyl acrylamide)-graft-poly(methyl methacrylate) (DMAA-g-MMA) membranes by pervaporation, the benzene-permselectivity of the DMAA-r-MMA membrane changed from the diffusivity selectivity to the solubility selectivity with increasing DMAA content but DMAA-g-MMA membranes with a high DMAA content had the higher apparent diffusivity selectivity than the apparent solubility selectivity. Furthermore, the apparent solubility selectivity for a benzene/cyclohexane mixture between the DMAA-r-MMA membrane and the DMAA-g-MMA membrane with a high DMAA content was remarkably different. These results were attributed to the difference of structure between the copolymers. Received: 27 August 1997/Revised version: 22 October 1997/Accepted: 30 October 1997     

Two-temperature chemically-non-equilibrium modeling of argon induction plasmas with diatomic gas

A non-equilibrium modeling of argon–oxygen and argon–hydrogen induction thermal plasmas was performed without thermal and chemical equilibrium assumptions. Reaction rates of dissociation and recombination of diatomic gas and ionization were taken into account with two-temperature modeling. A substantial deviation from LTE exists near the torch wall in argon–oxygen induction plasmas under atmospheric pressure, while small deviation in argon–hydrogen plasmas results from the large collision frequency between electrons and hydrogen atoms.     

Defect reduction in electrochemically deposited CdS thin films by annealing in 02

Using the electrochemical deposition method, CdS thin films were deposited from acid solutions (pH = 2.5) containing CdS0₄ and Na₂S₂0₃ on indium-oxide coated glass substrates. These films were annealed in N₂, air, or O₂ atmosphere at 200–500°C for 30 min. Photoluminescence spectra were measured at 77 K. For the films annealed in N₂, the band edge emission became weaker and the luminescence due to defects shifted to longer wavelengths as the annealing temperature was raised above 300°C. However, for the films annealed in air or O₂, the band edge emission was observed strongly irrespective of the annealing temperature and the luminescence due to defects was weak. Thus the O₂ annealing is useful for the defects reduction.     

Multi-component co-condensation model of Ti-based boride/silicide nanoparticle growth in induction thermal plasmas

Numerical analysis is conducted for the titanium-based boride and silicide nanoparticle synthesis using an induction thermal plasma including the material evaporation process and the nanoparticle growth process with nucleation and co-condensation. Both systems present the nano-scaled particle size distributions. Ti-B system shows the smaller particle diameter, sharper distribution, larger particle number density, and wider range of the composition than Ti-Si system. Ti-Si system provides a narrower range of the silicon content due to the simultaneous co-condensation of titanium and silicon. Finally the correlation between the particle size and the nonmetal content of the synthesized nanoparticles is presented on a chart.     

What are the sciences of relationship-centered primary care

Steroidogenic acute regulatory protein (StAR), a 30-kDa protein involved in the transport of cholesterol to inner mitochondrial membrane during stimulation of steroid hormone biosynthesis, has recently been cloned from human adrenals and MA-10 mouse Leydig tumor cells. We examined the regulation of StAR mRNA accumulation upon induction of steroidogenesis in immortalized rat granulosa cells. Granulosa cells were transfected with SV40 DNA alone (POGS5); with SV40 DNA and Ha-ras oncogene (POGRS1); with SV40 DNA, Ha-ras oncogene and LH/CG receptor (GLHR15) or with FSH receptor (GFSHR17) or with the beta 2-adrenergic receptor (G beta 2AR13) expression plasmids. Cells were cultured to confluency and then stimulated for 24 h with oFSH (4 nM), hCG (2.4 nM), isoproterenol (10 microM) or forskolin (50 microM). By quantitative RT-PCR, StAR mRNA was undetectable in non-steroidogenic cells (transfected with SV40 DNA alone, POGS5) either in the presence or in the absence of forskolin. In contrast, variable amount of the message was detected in all steroidogenic cell lines cotransfected with SV40 DNA and Ha-ras. Moreover, an increase in the StAR mRNA expression was evident in all steroidogenic cells upon stimulation with their respective agonists, concomitantly with enhanced progesterone production. The RT-PCR product was sequenced and the 379 base pairs of rat StAR were found to be 93% and 86% identical to mouse and human cDNA, respectively. The deduced 126 amino acid sequence was 95%, 88% and 88% identical to the mouse, human and bovine deduced protein sequences. We conclude that StAR message is expressed only in the steroidogenic rat granulosa cells and can be upregulated by FSH, hCG, isoproterenol and forskolin in the appropriate cell lines. In addition, we find that the rat StAR cDNA exhibit a high degree of homology with the mouse and human sequences.     

Simvastatin suppresses glomerular cell proliferation and macrophage infiltration in rats with mesangial proliferative nephritis

Inhibition of 3-hydro-3-methylglutaryl coenzyme A reductase inhibits the production of mevalonate and has been shown to suppress proliferation in many cell types. Therefore, 3-hydro-3-methylglutaryl coenzyme A reductase inhibitors may have a beneficial effect in glomerular disease, because glomerular cell proliferation is a central feature in the active glomerular injury. This study examines the effect of simvastatin on glomerular pathology in a rat mesangial proliferative glomerulonephritis (GN) induced by anti-thymocyte antibody (anti-Thy 1.1 GN). There was no difference in the degree of the antibody and complement-mediated initial injuries between simvastatin-treated and control GN rats. The most pronounced feature of simvastatin-treated GN was the suppression of the early glomerular cell proliferation. The proliferative activity was maximal at day 4 after disease induction (26.5+/-7.0 of proliferating cell nuclear antigen-positive cells/glomerulus); however, approximately 70% of proliferation was suppressed by simvastatin treatment. At day 4 after disease induction, simvastatin administration also decreased alpha-smooth muscle actin expression in the glomerulus, which is a marker for mesangial cell activation. Inhibition of monocyte/macrophage recruitment into glomeruli by simvastatin was also a prominent feature. There was a 30% decrease in the number of glomerular ED-1+ cells by simvastatin treatment at day 2 after disease induction. Furthermore, simvastatin remarkably suppressed subsequent mesangial matrix expansion and type IV collagen accumulation in glomeruli. We also found that the platelet-derived growth factor expression was reduced in simvastatin-treated nephritic rats, which might simply reflect the reduction in mesangial cell proliferation and mesangial cellularity. There was no significant difference in plasma cholesterol or triglyceride levels between simvastatin- and vehicle-treated nephritic rats at day 2 and day 4, which corresponded to the times when simvastatin treatment resulted in a reduction in mesangial cell proliferation. In conclusion, this is the first report to find that mesangial cell proliferation and matrix expansion have been blocked by simvastatin in vivo. The protective effect of simvastatin in the matrix expansion in anti-Thy1.1 GN was partly by inhibition of mesangial cell proliferation and monocyte/ macrophage recruitment into glomeruli, which were independent of a change in circulating lipids.     

Improvement in stabilization of launching performance and launching velocity using linear accelerator

This paper describes the improvements in launching stability and launching velocity of the linear accelerator (LAC). The authors have designed and produced a railgun using the LAC for weaving loom shuttles. The LAC is an electromagnetic launcher which enables a projectile to be launched at a speed of more than 50 m/s. Basically, it consists of a unipole linear dc motor and operates the same principle as dc rotary motors, the most difficult problem in this system being the stabilization of the current collection on the projectile. Then, various launch experiments have been conducted. As a result, the carbon projectile was launched at a speed of 73 m/s using double-state-type LAC.