A Gln/Arg polymorphism at codon 349 of the hBUBR1 gene

We found a glutamine/arginine polymorphism at codon 349 of the hBUBR1 gene, encoding a protein kinase required for spindle assembly checkpoint function. The observed heterozygosity was estimated to be 45% in the Japanese population. This polymorphism may be helpful for genetic studies of many cancer types in which chromosomal instability is observed. Received: October 19, 1998 / Accepted: October 24, 1998     

Histopathological studies on virulence of dipeptidyl aminopeptidase IV (DPPIV) of Porphyromonas gingivalis in a mouse abscess model: use of a DPPIV-deficient mutant

To elucidate the role of dipeptidyl aminopeptidase IV (DPPIV) in the virulence of Porphyromonas gingivalis, mice were infected with either a wild-type strain or a DPPIV-deficient mutant using an abscess model. Histopathological analysis of the resulting lesions indicated that DPPIV participates in virulence through the destruction of connective tissue and the less effective mobilization of inflammatory cells.     

Pathogenesis of Rinderpest Virus Infection in Rabbits I. Clinical Signs, Immune Response, Histological Changes, and Virus Growth Patterns

Rabbits were intravenously inoculated with an attenuated rinderpest virus (L strain), and general patterns of the disease were investigated. The rabbits developed fever with concomitant occurrence of diarrhea and lymphopenia. Early production of interferon was followed by a rise of neutralizing antibody. Histological examinations revealed an involvement of all of the lymphoid tissues, with primary lesions consisting of necrosis of the lymphoid follicles and formation of giant cells. Immunofluorescent examinations suggested that the virus growth was present in almost all of the lymphoid tissues. The possibility of application of this experimental system for the study of systemic infection by measles virus was discussed.     

Formation of quinone methide in the self-cure of quinoid phenol formaldehyde resin

The study of the reaction of some methylenebisphenols with chloranil in ethanol and also of a phenol formaldehyde condensate prepared by acid catalysis, reveals that quinone methide is formed in the self-cure of quinoid phenol formaldehyde resin. The quinone methide reacts with ethanol to give an adduct. The structure of the alcohol adduct is identified by NMR and IR data and by means of pyrolysis.     

Mutations in the gene encoding KIAA1199 protein,an inner-ear protein expressed in Deiters’ cells and the fibrocytes,as the cause of nonsyndromic hearing loss

We report three possibly disease-causing point mutations in one of the inner-ear-specific genes, KIAA1199. We identified an R187C mutation in one family, an R187H mutation in two unrelated families, and an H783Y mutation in one sporadic case of nonsyndromic hearing loss. In situ hybridization indicated that the murine homolog of KIAA1199 mRNA is expressed specifically in Deiters cells in the organ of Corti at postnatal day zero (Pn) P0 before the onset of hearing, but expression in those cells disappears by day P7. The signal of KIAA1199 was also observed in fibrocytes of the spiral ligament and the spiral limbus through to P21, when the murine cochlea matures. Thus, the gene product may be involved in uptake of potassium ions or trophic factors with a particular role in auditory development. Although the R187C and R187H mutations did not appear to affect subcellular localization of the gene product in vitro, the H783Y mutation did present an unusual cytoplasmic distribution pattern that could underlie the molecular mechanism of hearing impairment. Our data bring attention to a novel candidate for hearing loss and indicate that screening of mutations in inner-ear-specific genes is likely to be an efficient approach to finding genetic elements responsible for deafness.Nucleotide sequence data reported herein are available in the DDBJ/EMBL/GenBank databases; for details, see the electronic eatabase section of this article.     

Inhibition of experimental metastasis and cell adhesion of murine melanoma cells by chondroitin sulfate-derivatized lipid, a neoproteoglycan with anti-cell adhesion activity

Chondroitin sulfate dipalmitoylphosphatidylethanolamine (CS-PE), when immobilized onto substratum, inhibited the adhesion of B16F10 mouse melanoma cells to fibronectin-coated dishes (anti-adhesion activity). CS-PE showed the most potent anti-adhesion activity for the melanoma cells among various GAG-PEs. CS-PE also inhibited the adhesion of B16F10 cells to Matrigel and the invasion of the cells into Matrigel. In the in vivo system of experimental metastasis, administration of B16F10 cells with CS-PE into C57BL/6 mice significantly inhibited lung metastasis. The inhibition degree of CS or hyaluronic acid-PE was lower than CS-PE. CS-PE administered intravenously into mice before the injection of B16F10 cells also inhibited metastasis. Pretreatment of B16F10 cells with CS-PE caused some but a lower degree of inhibition. When CS-PE was injected intravenously into mice, more binding in the lung was found than when CS was injected. CS-PE but not CS inhibited the retention in the lung of fluorochrome-labeled B16F10 cells when injected intravenously into mice. Since there was no significant effect of CS-PE on the viability and growth of B16F10 cells, the results suggest that CS-PE immobilized onto the subendothelial matrix may prevent melanoma cells from adhering to the subendothelial substrata of lung capillaries and inhibit subsequent invasion processes of metastasis.     

Pathogenic mechanism of mouse brain damage caused by oral infection with Shiga toxin-producing Escherichia coli O157:H7

In a previous study, we showed that infection with Shiga toxin (Stx)-producing Escherichia coli O157:H7 (strain Sm(r)N-9) caused neurologic symptoms in malnourished mice with positive immunoreactions of Stx2 in brain tissues. The present study explores the mechanism of how Stx injures the vascular endothelium to enter the central nervous system in mice. Oral infection with strain Sm(r)N-9 elicited a tumor necrosis factor alpha (TNF-alpha) response in the blood as early as 2 days after infection, while Stx was first detected at 3 days postinfection. In the brain, TNF-alpha was detected at day 3, and its quantity was increased over the next 3 days. Frozen sections of the brains from moribound mice contained high numbers of apoptotic cells. Glycolipids recognized by an anti-Gb3 monoclonal antibody were extracted from the brain, and purified Stx2 was able to bind to the glycolipids. In human umbilical vascular endothelial cells (HUVEC) cultured with fluorescein-labeled Stx2 (100 ng/ml), TNF-alpha (20 U/ml) significantly facilitated the intracellular compartmentalization of fluorescence during 24 h of incubation, suggesting the enhanced intracellular processing of Stx2. Consequently, higher levels of apoptosis in HUVEC were found at 48 h. Short-term exposure of HUVEC to Stx2 abrogated their apoptotic response to subsequent incubation with TNF-alpha alone or TNF-alpha and Stx2. In contrast, primary exposure of HUVEC to TNF-alpha followed by exposure to Stx2 alone or TNF-alpha and Stx2 induced apoptosis at the same level as obtained after 48-h incubation with these two agents. These results suggest that the rapid production of circulating TNF-alpha after infection induces a state of competence in vascular endothelial cells to undergo apoptosis, which would be finally achieved by subsequent elevation of Stx in the blood. In this synergistic action, target cells must be first exposed to TNF-alpha. Such cell injury may be a prerequisite to brain damage after infection with Stx-producing E. coli O157:H7.     

Simultaneous infection with human herpesvirus-6 and measles virus in infants

Two infants (4 and 5 months of age) with a febrile episode for 3 and 5 days, respectively, developed skin rashes after the fever subsided and were diagnosed as exanthem subitum. The rash continued for 5 days followed by mild-to-moderate pigmentation. Human herpesvirus-6 and measles virus, which were confirmed by a specific immunofluorescence assay and by electron microscopy, were isolated simultaneously from blood in the acute stage of the disease but not from the convalescent stage. The titer of the herpesvirus-6 in blood was greater than that of measles. Specific serologic assays showed marked seroconversion against human herpesvirus-6 but not to measles virus. The results suggest that dual infection with human herpesvirus-6 and measles virus results in atypical exanthem subitum or modified measles with unique immunologic responses.