An improved method for the detection of HIV antigen in the blood of carriers

The measurement of HIV antigen levels in sera or plasma of HIV-infected individuals is critical for determining the existence of antigen or infectious virus before seroconversion and for prognosis. Pretreatment of sera or plasma of HIV carriers by heating at 70 degrees C for 10 min at an acidic pH enabled us to estimate antigens efficiently in immune complexes. This procedure will also be useful in determining antigen levels in HIV carriers more precisely.     

Studies on the osmophilic fungus Wallemia sebi as an allergen evaluated by skin prick test and radioallergosorbent test

Recently, Wallemia sebi, a species of osmophilic fungi, has been abundantly detected in house dust using low water activity media. In this study, allergenic activity of W. sebi was assessed by skin prick test and radioallergosorbent test (RAST) in 74 asthmatic patients ranging from 6 to 32 years of age. Aspergillus fumigatus and house dust were used for comparison. In skin prick test, W. sebi extract, A. fumigatus extract and house dust extract elicited positive reactions in 4 (5.4%), 4 (5.4%) and 51 (68.9%) patients, respectively. RAST showed positive results in 14 subjects (18.9%) for W. sebi extract, in 8 (10.8%) for A. fumigatus extract and in 59 (79.7%) for house dust extract. These results indicated that some asthmatic individuals showed immediate-type hypersensitivity to W. sebi, and which means this fungal species may be of importance to atopic diseases as a causative agent.     

Detection of cytomegalovirus in urine samples by an enzyme-linked immunosorbent assay using a monoclonal antibody against the viral 150-kilodalton protein.

McKeating et al. (J.A. McKeating, P.D. Griffiths, and J.E. Grundy, J. Gen. Virol. 68:785-792, 1987; J. A. McKeating, J. E. Grundy, Z. Varghese, and P. D. Griffiths, J. Med. Virol. 18:341-348, 1986; J. A. McKeating, S. Stagno, P. R. Stirk, and P. D. Griffiths, J. Med. Virol. 16:367-373, 1985) reported previously that beta 2 microglobulin inhibits the detection of human cytomegalovirus (CMV) in urine specimens by an enzyme-linked immunosorbent assay (ELISA) with a monoclonal antibody against the glycoprotein of CMV. They postulated that beta 2 microglobulin binds to the viral glycoproteins and masks the antigenic determinants. We developed here an ELISA method for the detection of CMV in urine by using a monoclonal antibody against the viral 150-kDa protein to capture the viral antigen. This assay detected CMV both in culture medium and in urine specifically at concentrations higher than 10(3) PFU/ml and quantitatively at concentrations higher than 10(4) PFU/ml. The sensitivity of the ELISA increased about 10-fold when peroxidase-labeled F(ab')2 from goat anti-human immunoglobulin G was used as a secondary detecting antibody in combination with concentration of the virus in urine samples by ultracentrifugation. The inhibition of ELISA by beta 2 microglobulin was not observed in this ELISA system. When 56 urine specimens from renal transplant recipients were examined for CMV antigens, the ELISA system had a sensitivity of 78% and a specificity of 97%. The positive and negative predictive values of the assay were 95 and 86%, respectively. Furthermore, CMV antigens in urine were quantitated by the assay during the course of typical CMV disease of renal transplant recipient. These results suggest strongly that the measurement of CMV antigens in urine by our rapid and quantitative ELISA system provides very useful data for the monitoring of CMV infections in renal transplant recipients and making decisions about therapy.     

Identification of fibroin-derived peptides enhancing the proliferation of cultured human skin fibroblasts

We previously reported that the fibroin of the silkworm Bombyx mori enhanced the proliferation of cultured human skin fibroblasts. In this work, the fibroin was digested by chymotrypsin, and the resulting peptide fragments were fractionated and assayed for their biological activity. Two peptides that promoted fibroblast growth were isolated and identified to be VITTDSDGNE and NINDFDED. Both sequences are found in the N-terminal region of the fibroin polypeptide and are thought to be the active principle of fibroblast growth-promoting activity.     

Vp130, a chloroviral surface protein that interacts with the host Chlorella cell wall

A protein, Vp130, that interacts with the host cell wall was isolated from Chlorovirus CVK2. From its peptide sequence, the gene for Vp130 was identified on the PBCV-1 genomic sequence as an ORF combining A140R and A145R. In Vp130, the N-terminus was somehow modified and the C-terminus was occupied by 23-26 tandem repeats of a PAPK motif. In the internal region, Vp130 contained seven repeats of 70-73 amino acids, each copy of which was separated by PAPK sequences. This protein was well conserved among NC64A viruses. A recombinant rVp130N protein formed in Escherichia coli was shown not only to bind directly to the host cell wall in vitro but also to specifically bind to the host cells, as demonstrated by fluorescence microscopy. Because externally added rVp130N competed with CVK2 to bind to host cells, Vp130 is most likely to be a host-recognizing protein on the virion.     

Migration of enhanced green fluorescent protein expressing bone marrow-derived microglia/macrophage into the mouse brain following permanent focal ischemia

Brain ischemia induces a marked response of resident microglia and hematopoietic cells including monocytes/macrophages. The present study was designed to assess the distribution of microglia/macrophages in cerebral ischemia using bone marrow chimera mice known to express enhanced green fluorescent protein (EGFP). At 24 h after middle cerebral artery occlusion (MCAO), many round-shaped EGFP-positive cells migrated to the ischemic core and peri-infarct area. At 48-72 h after MCAO, irregular round- or oval-shaped EGFP/ionized calcium-binding adapter molecule 1 (Iba 1)-positive cells increased in the transition zone, while many amoeboid-shaped or large-cell-body EGFP/Iba 1-positive cells were increased in number in the innermost area of ischemia. At 7 days after MCAO, many process-bearing ramified shaped EGFP/Iba 1-positive cells were detected in the transition to the peri-infarct area, while phagocytic cells were distributed in the transition to the core area of the infarction. The distribution of these morphologically variable EGFP/Iba 1-positive cells was similar up to 14 days from MCAO. The present study directly showed the migration and distribution of bone marrow-derived monocytes/macrophages and the relationship between resident microglia and infiltrated hematogenous element in ischemic mouse brain. It is important to study the distribution of intrinsic and extrinsic microglia/macrophage in ischemic brain, since such findings may allow the design of appropriate gene-delivery system using exogenous microglia/macrophages to the ischemic brain area.     

Terminal deoxynucleotidyltransferase forms a ternary complex with a novel chromatin remodeling protein with 82 kDa and core histone

BACKGROUND: Terminal deoxynucleotidyltransferase (TdT) is a DNA polymerase that enhances the Ig and TcR gene diversity in the N region at the junctions of variable (V), diversity (D) and joining (J) segments in B- and T-cells. TdT synthesizes the N region in concert with many proteins including DNA-PKcs, Ku70 and Ku86. To elucidate the molecular mechanism of the N region synthesis, we first attempted to isolate the genes with products that directly interact with TdT. RESULTS: Using a yeast two-hybrid system, we isolated a cDNA clone encoding a novel nuclear protein that interacts with TdT. This protein was designated as TdT interacting factor 2 (TdIF2). The confined region of the C-terminal in TdIF2 is involved in specific interaction with the entire C-terminal in TdT. TdIF2 contains an acidic region comprised of 42 residues. TdIF2 was shown to bind specifically to a core histone by pull down assay using specific antibodies against TdIF2. When a TdT/TdIF2 complex was applied on to a DNA-cellulose column, only TdT bound to the column while TdIF2 passed through. TdIF2 reduces the TdT activity to 46% of its maximum value in vitro assay system using activated DNA as primer. CONCLUSIONS: TdIF2 binds directly to TdT and core histone. Furthermore, TdT, TdIF2 and core histone form a ternary complex. TdIF2 liberates H2A/H2B from a core histone in correlation with PCNA. The enzymatic consequence of the TdIF2/TdT complex is the reduction of TdT activity in vitro. TdIF2 would function as a chromatin remodeling protein at the N region synthesis.     

Copolymerization of N-carboxy-γ-benzyl-L-glutamate anhydride and alkylene oxides by organometallic compounds

Copolymerization of N-carboxy-γ-benzyl-L -glutamate anhydride and ethylene oxide or DL-propylene oxide was carried out in the presence of triethylaluminum or diethylzine as catalyst with (or without) dioxane as solvent. From the data obtained by nuclear magnetic resonance spectroscopy, optical rotatory dispersion measurements, infrared absorption spectroscopy and turbidimetry, it was concluded that the copolymer obtained by the triethylaluminum catalyst consisted of two parts, peptide-block part and random or alternate part, while diethylzinc catalyst resulted in the formation of a less random copolymer only. In dioxane, formation of peptide-block part by triethylaluminum was suppressed to some extent.     

Asymptomatic infection of mouse hepatitis virus in the rat

Summary After intranasal inoculation of suckling rats mouse hepatitis virus multiplied mostly in the nasal epithelium; though there were no symptoms, antibodies were produced. Antibodies were also demonstrated in adult rats. These findings suggest that the rat may be a natural host for the virus.With 2 Figures