Primary human immunodeficiency virus type 1 viremia and central nervous system invasion in a novel hu-PBL-immunodeficient mouse strain

We established four new mouse strains with defective T and B cells as well as defects in innate immunological reactions using an NK cell depletion antibody and showed that all mutant mouse strains efficiently received human peripheral blood leukocyte (PBL) engraftment (hu-PBL-scid mice). Higher levels of human immunodeficiency virus type 1 (HIV-1) replication were observed in these new hu-PBL-scid mice than in conventional hu-PBL-C.B-17-scid mice. In one particular strain, hu-PBL-NOD-scid mice, high levels of HIV-1 viremia (more than 10(6) 50% infectious doses per ml) were detected after infection with HIV-1. The plasma viral load was about 100 to 1,000 times higher than that observed in other hu-PBL-scid mice infected with HIV-1. Although high-level viremia did not correlate with the total amount of HIV-1 RNA in cells from infected mice, high levels of free virions were detected only in hu-PBL-NOD-scid mice. HIV-1 viremia induced systemic HIV-1 infection involving the liver, lungs, and brain. PCR in situ hybridization confirmed that HIV-1-infected cells invaded the brain tissue of the hu-PBL-NOD-scid mice. Our results suggest that the genetic background, including innate immunity, is critical in the development of primary HIV-1 viremia and subsequent central nervous system invasion with HIV-1. The hu-PBL-NOD-scid mouse represents a useful model for the study of the pathogenesis of HIV-1 in vivo, especially brain involvement, and therapy of primary HIV-1 viremia.     

Genoepidemiology and pathogenicity of hepatitis G virus in Japan

Danish artificial insemination (AI) centres house several boars antibody positive to porcine reproductive and respiratory syndrome virus as well as PRRSV-naive boars which may become acutely infected. The risk of transmission of PRRSV by semen may therefore constitute a serious problem to the Danish pig industry. The use of a vaccination-program may be a way to avoid or reduce the problem. This study evaluates the use of two vaccines: One live, attenuated vaccine and one inactivated vaccine. A pronounced reduction in viremia and shedding of virus in semen was demonstrated by use of the live vaccine compared to the non-vaccinated control animals. In contrast, no changes in onset, level and duration of viremia and shedding of virus in semen were observed using the inactivated vaccine. Neither viremia nor seminal shedding of virus was detected in previously PRRSV-infected, PRRSV-antibody positive boars after challenge with a Danish field strain of PRRSV.     

Production of rabbit polyclonal antibody against apobec-1 by genetic immunization

Circulating apolipoprotein B (apoB) exists in two forms; apoB-100 and apoB-48. ApoB-48 is a truncated form of apoB resulting from RNA editing. The editing enzyme, called apobec-1, converts a cytidine (C) at nucleotide 6666 in apoB 100 mRNA to a uridine (U) and changes a CAA codon to an in-frame stop codon, UAA. We have produced a specific rabbit polyclonal antiserum against apobec-1 by genetic immunization. The cDNA of mouse apobec-1 was inserted downstream and in-frame at the BamH I site in the last exon of human growth hormone cDNA driven by a cytomegalovirus promoter. This plasmid was injected together with another plasmid expressing granulocyte macrophage colony-stimulating factor into the thigh muscles of a rabbit. The resulting antiserum demonstrated high specificity on Western blots, and inhibited the apoB mRNA editing activity of mouse liver extract in a dose-dependent manner. This report demonstrates that DNA immunization is a powerful technique that can be readily applied to other sparse or difficult-to-purify proteins in lipid metabolism.     

Independent control of mechanical and chemical properties of monodispersed polystyrene–divinyl benzene microspheres by two-step polymerization

Monodispersed polystyrene (PS) latices of the particle size ranging between 4 and 10 μm were prepared by a conventional dispersion polymerization technique using poly-(acrylamide) as a stabilizer. Styrene containing 2–20% of divinyl benzene (DVB) was subsequently polymerized on the surface of the latex by a seeded polymerization technique for the purpose of modifying the thermo-mechanical and chemical properties of the microspheres. The softening temperature during hot pressing and the resistance against the dissolution on swelling in toluene or methyl ethyl ketone increased with increasing amount of DVB. The state of seeded polymerized particles was revealed to depend more on the total amount than the composition of the monomer added. By using the present technique, it is possible to prepare chemically stable, monodispersed microspheres with their diameters and softening temperature varying from 4.5 to 12 μm and from 106 to 126°C, respectively, with a free combination by choosing the appropriate dispersion polymerization condition and the amount of DVB during subsequent seeded polymerization.     

Peg5/Neuronatin is an imprinted gene located on sub-distal chromosome 2 in the mouse

We have established a systematic screen for imprinted genes using a subtraction-hybridization method with day 8.5 fertilized and parthenogenetic embryos. Two novel imprinted genes, Peg1/Mest and Peg3, were identified previously by this method, along with the two known imprinted genes, Igf2 and Snrpn. Recently three additional candidate imprinted genes, Peg5-7 , were detected and Peg5 is analyzed further in this study. The cDNA sequence of Peg5 is identical to Neuronatin, a gene recently reported to be expressed mainly in the brain. Two novel spliced forms were detected with some additional sequence in the middle of the known Neuronatin sequences. All alternatively spliced forms of Peg5 were expressed only from the paternal allele, confirmed using DNA polymorphism in a subinterspecific cross. Peg5/Neuronatin maps to sub-distal Chr 2, proximal to the previously established imprinted region where imprinted genes cause abnormal shape and behavior in neonates.     

Rotating-disc type high voltage generator

A very compact electrostatic generator, making use of a rotating insulator disc equipped with charge-carrying metallic pieces in an SF₆ atmosphere, has been constructed and used for a preacceleration voltage source of a tandem accelerator. The maximum usable voltage is 400 kV, generating a current of 500 μA. The charge transfer to and from the moving charge carriers at the ground and high voltage terminals is performed by means of a contact with running conducting rubber belts.     

A novel biomarker for hyperglycemia, MRX isolated from hydrolysate of glycated proteins

Long-lived proteins can undergo non-enzymatic glycation to form highly crosslinked structures with characteristic fluorescence during aging and diabetes processes. In this paper, a typical fluorophore, named Maillard reaction product X (MRX), was isolated from the hydrolysate of glycated proteins. MRX could be formed by incubation of bovine serum albumin with glucose, followed by acid hydrolysis. The structure of MRX was determined to be 8-hydroxy-5-methyldihydrothiazolo[3,2-alpha] pyridinium-3-carboxylate. MRX was also found to be formed by the incubation of cysteine and arginine with glucose, followed by hydrolysis. We found the formation of MRX in the recently developed genetically diabetic Otsuka Long-Evans Tokushima Fatty (OLETF) rats and compared them with that in the control Long-Evans Tokushima Otsuka (LETO) rats. Significantly higher levels of MRX were observed from the serum (p < 0.005) and urinary protein (p < 0.001) of OLETF rats in comparison with those of LETO rats. MRX must be a potential candidate as a biomarker for hyperglycemia.     

Selective permeation of o-, m-, and p-isomers of benzene derivatives through polymer membranes based on cyclodextrin complexation in the bulk aqueous solution

Transport behavior of several aromatic compounds through a poly(vinyl chloride)membrane and poly(vinyl alcohol)-poly(ethylenimine) composite membranes was studied in the presence of cyclodextrin in the aqueous solution. o-Isomers of nitrophenol, nitroaniline, and iodophenol were effectively separated from their mixture of regio isomers based on the preferential complexation between cyclodextrin and the m- and p-isomers over the o-isomers. Pumping of p-nitroaniline across the membrane was also observed by addition of cyclodextrin. The results were explained as a consequence of the selective complex formation between cyclodexarin and substrate and the low membrane permeability of the complexes.     

High-silica multimode channel waveguide structure for minimizing fiber-waveguide-fiber coupling loss

The optimum structure for high-silica channel waveguides which are connected to input and output graded-index fibers having a 50-μm core diameter and a 1.0-percent refractive-index difference is studied theoretically and experimentally. Theoretical optimum waveguide structure is obtained on the basis of ray optic analysis. For the step-index waveguide with 1.0-percent refractive-index difference, the theoretical minimum coupling loss (input coupling loss + output coupling loss) is 1.7 dB for an optimum core of 38 μm both in depth and width. For the graded-index waveguide with parabolic-index profile in the depth direction and step-index profile in the width direction, the theoretical coupling loss is 1.1 dB for an optimum core of 38 μm in width and 50 μm in depth. These estimations were in good agreement with the experimental results, which were 1.8 dB for the step-index waveguide and 1.3 dB for the graded-index waveguide.