Mechanism of water-insoluble glucan synthesis in Streptococcus sobrinus.

Synthesis of water-insoluble glucan (IG) by 1,3-alpha-D-glucan synthase from Streptococcus sobrinus was examined using methylation analysis. The purified enzyme was incubated with sucrose and dextran T2000 (DT2000) for a given time and only IG was harvested by centrifugation. The remaining supernatant was incubated again, and IG was obtained.

Relapse of herpes simplex encephalitis in children.

The polymerase chain reaction method was used to diagnose herpes simplex encephalitis in children. Initial samples of cerebrospinal fluid from 15 patients with herpes simplex encephalitis were all positive for the herpes simplex virus DNA by polymerase chain reaction assay. In terms of early diagnosis, polymerase chain reaction assay became positive significantly earlier than the detection of intrathecally produced anti-herpes simplex virus antibody using the enzyme-linked immunosorbent assay (4.

Prophylactic oral acyclovir in outbreaks of primary herpes simplex virus type 1 infection in a closed community.

Oral acyclovir was given prophylactically to 37 children in the early stages of three outbreaks of herpes simplex virus type 1 (HSV-1) infection and the results were compared with those in untreated control subjects in two other outbreaks. The rates of seroconversion to HSV were significantly reduced in children treated with acyclovir compared with control subjects (91% vs 27%, P less than .001).

Cloning of a Streptococcus sobrinus gtf gene that encodes a glucosyltransferase which produces a high-molecular-weight water-soluble glucan.

The gtf gene coding for glucosyltransferase (GTF), which produces a water-soluble glucan, was cloned from Streptococcus sobrinus OMZ176 (serotype d) into plasmid vector pBR322. This gene was expressed in Escherichia coli, and the product was purified to near homogeneity. The antigenicity of recombinant GTF (rGTF) was examined with the antisera raised against purified GTF P1, P2, P3, and P4 obtained from S.

The extension of alpha-D-1,3-branch linkages by 1,3-alpha-D-glucan synthase from Streptococcus sobrinus.

In the presence of an acceptor, 1,3-alpha-D-glucan synthase of Streptococcus sobrinus synthesizes water-insoluble glucans from sucrose. Under such conditions, 1,3-alpha-D-glucoside linkages were extended without any change in the glucose-residue number between the 1,3,6-branch points on the acceptor. From these results, the mechanisms of water-insoluble-glucan formation were proposed as follows: (i) the attachment of an acceptor to the glucan binding sites of 1,3-alpha-D-glucan synthase occurs during the initiation of the reaction, and concurrently determines the positions of the branched portions of 1,3,6 on the acceptor, and (ii) the 1,3-alpha-D-glucoside linkage extends from these positions.

Clinical manifestations of primary herpes simplex virus type 1 infection in a closed community.

The clinical features and the molecular epidemiology of primary herpes simplex virus type 1 (HSV-1) infection among children younger than 3 years of age were investigated in day-care nursery. Serial sera were assayed for anti-HSV-1 glycoprotein B antibody by enzyme-linked immunosorbent assay. Serologic examinations revealed 55 cases of primary HSV infection during the observation period.

Substrate specificity of hydrolase activity of the primer-dependent glucosyltransferases from Streptococcus sobrinus.

Four kinds of glucosyltransferases, P1, P2, P3 and P4, were separately purified from the culture supernatant of Streptococcus sobrinus. Their dependencies on primer were analysed. There were two primer-dependent glucosyltransferases (P3 and P4).

Rapidly progressive renal failure associated with angiofollicular lymph node hyperplasia.

The authors report a case of rapidly progressive renal failure associated with Castleman's disease. Renal biopsy revealed crescentic glomerulonephritis associated with marked tubulointerstitial nephritis. This kind of renal lesion has never been reported in association with angiofollicular lymph node hyperplasia (Castleman's disease) or other immunoblastic disorders.

Purification and characterization of alkaline phosphatase of Bacteroides gingivalis 381.

Cell-associated alkaline phosphatase (ALPase) of Bacteroides gingivalis 381 was found in the outer part of the periplasmic space by using an ultracytochemical procedure. Cell-associated ALPase was solubilized by extraction with 1% Triton X-100, and the solubilized enzyme was purified 904-fold with 5.6% recovery by using affinity column chromatography for mammalian intestinal-form ALPase.

Characterization of the product of the gtfS gene of Streptococcus downei, a primer-independent enzyme synthesizing oligo-isomaltosaccharides.

The gtfS gene, coding for a glucosyltransferase which synthesizes water-soluble glucan and previously cloned from Streptococcus downei strain MFe28 (mutans serotype h) into a bacteriophage vector, was subcloned into a plasmid vector. The gtfS gene products expressed in Escherichia coli were compared to the primer-independent, oligo-isomaltosaccharide synthase in Streptococcus sobrinus strain AHT (mutans serotype g) and shown to resemble it closely in molecular mass, isoelectric point, immunological properties, optimum pH and Km values. The glucans produced from sucrose by the gtfS gene products are alpha-1,6-linked linear oligo-isomaltosaccharides without any branching sites.

Human cytomegalovirus infection during childhood: detection of viral DNA in peripheral blood by means of polymerase chain reaction.

Polymerase chain reaction (PCR) technique was applied to detect cytomegalovirus (CMV) DNA. Two pairs of synthetic oligonucleotide primers were used to amplify DNA from the immediate early 1 and the late antigen genes of CMV, respectively. Either primer sets could detect as few as 0.

Purification of a fourth glucosyltransferase from Streptococcus sobrinus.

Recently, we found a novel primer-independent, water-soluble glucan synthase as a fourth glucosyltransferase (GTF) in a culture supernatant of strain AHT-k of Streptococcus sobrinus (Y. Yamashita, N. Hanada, and T.

Combined effects of acyclovir and human interferon-alpha on herpes simplex virus replication in cultured neural cells.

The combined effects of Acyclovir [9-(2'-hydroxyethoxymethyl)guanine; ACV] and human interferon-alpha (IFN-alpha) on replication of the herpes simplex virus type I (HSV-1) were determined in human neural cell lines, neuroblastoma (IMR), glioblastoma (118MGC), and glioma (U251MG). HSV-1 grew well in all these cells, with final yields of more than 1 x 10(6) PFU/ml. In terms of virus-yield reduction, ACV was found to be highly effective in IMR, moderately effective in U251MG, but ineffective in 118MGC.

Isolation and characterization of the Streptococcus mutans gtfD gene, coding for primer-dependent soluble glucan synthesis.

Two glucosyltransferase genes from Streptococcus mutans GS-5, gtfB and gtfC, have been previously isolated and sequenced in this laboratory. In the present communication a third gtf gene, gtfD, was isolated and characterized. Isolation of the gene involved a novel procedure utilizing the integration plasmid pVA891.

Periodontal disease prevalence in different age groups in Japan as assessed according to the CPITN.

A CPITN survey was conducted involving 12,832 Japanese subjects from 7 to 64 years of age. Subjects under 18 were schoolchildren, and 18-year-old and older subjects represented various social backgrounds, having been randomly selected from both urban and rural Japan. Fifty percent of the 7-yr-old children had signs of periodontal disease, and this percentage increased with increasing age.

Evidence for the presence of two distinct sites of sucrose hydrolysis and glucosyl transfer activities on 1,3-alpha-D-glucan synthase of Streptococcus mutans.

1,3-alpha-D-Glucan synthase of Streptococcus mutans catalyzes both the hydrolysis of sucrose to glucose and fructose, and the glucosyl transfer to glucosyl polymers to yield water-insoluble glucan. The enzyme catalyzes only sucrose hydrolysis, however, in the absence of 1,6-alpha-D-glucan as an acceptor. In the present study, we found that glucosyl transfer activity was completely inhibited by the antiserum against isolated 1,3-alpha-D-glucan synthase but that the sucrose hydrolysis activity was not.

Non-invasive method for early diagnosis of herpes simplex encephalitis.

For the early diagnosis of herpes simplex encephalitis IgG and IgM antibodies to herpes simplex virus in cerebrospinal fluid were measured by an enzyme linked immunosorbent assay (ELISA) and a local production index was calculated. Using these three criteria, 31 cases of various neurological illnesses were analysed. All eight cases of herpes simplex encephalitis were diagnosed correctly in the acute phase, and there were no false positive results.

Isolation and characterization of the Streptococcus mutans gtfC gene, coding for synthesis of both soluble and insoluble glucans.

The intact gtfC gene from Streptococcus mutans GS-5 was isolated in Escherichia coli in plasmid vector pUC18. The glucosyltransferase activity expressed by the gene synthesized both low-molecular-weight water-soluble glucan and insoluble glucan in a primer-independent manner. Purification of the enzyme by procedures that minimize proteolytic digestion yielded a purified preparation with a molecular weight of 140,000.

Immunological properties of the primer-independent glucosyltransferase of Streptococcus mutans serotypes d and g.

Streptococcus mutans serotype g secretes at least three kinds of glucosyltransferase with different enzymological and immunological properties. One of them is a primer-independent enzyme and seems to be the source of primer for the others, both of which are primer-dependent enzymes. Recently, we purified the primer-independent enzyme, the third glucosyltransferase in this group from S.

A novel glucosyltransferase from Streptococcus mutans produces oligo-isomaltosaccharides.

Streptococcus mutans secretes a sucrose-independent branalphang enzyme that utilizes isomaltosaccharides as donors for branalphang formation on dextran. Although the branching enzyme is necessary for the formation of extracellular polysaccharide complexes, the source of the donor for the enzyme is unknown. In this study, we purified a novel glucosyltransferase from S.

Purification and characterization of a third glucosyltransferase from Streptococcus mutans serotype g.

Streptococcus mutans strain AHT (serotype g) secretes at least two glucosyltransferases with different pI values. A novel glucosyltransferase with a pI of 5.8 was purified 244-fold from the ammonium sulphate fraction by DEAE-cellulose chromatography, FPLC (Mono Q column, Pharmacia) and hydrophobic chromatography.

Local production of rotavirus specific IgA in breast tissue and transfer to neonates.

Rotavirus specific IgA, secretory component, and IgG were measured by enzyme linked immunosorbent assay in 20 pairs of mothers and babies to estimate antibody transfer from the mother, particularly from breast milk to neonatal faeces. Colostrum contained high titres of specific IgA and secretory component, which decreased gradually. Faeces after breast feeding for three days showed detectable titres of IgA and secretory component, with further increases by seven days.

Antigenic characterization of the internal proteins of Newcastle disease virus by monoclonal antibodies.

We have prepared and characterized monoclonal antibodies against the three internal structural proteins, M, P and NP, of Newcastle disease virus. At least two non-overlapping antigenic sites were delineated on the M protein, four on the P, and two on the NP by competitive binding assay. One of the two non-overlapping antigenic sites on the M protein was found to be a cluster of at least three distinct epitopes.

Comparison of different water-soluble glucan synthases from Streptococcus mutans serotype g.

A novel glucosyltransferase that synthesizes low molecular weight water-soluble glucan was partially purified from Streptococcus mutans AHT cell-free culture supernatant. This enzyme was compared with another water-soluble glucan synthase which synthesized high molecular weight glucan.