Biomedical subjects
Masami Yoshida
Publications and source records attributed to Masami Yoshida.
[Diagnostic tests: Herpes simplex virus type 1 and 2].
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High frequency of detection of herpes simplex virus DNA in the oral cavity of patients with eczema herpeticum.
BACKGROUND: It has been reported that herpes simplex virus (HSV) DNA was detected in the oral cavity of patients with herpes labialis under various conditions such as during oral surgery. OBJECTIVE: The frequency of detection of oral HSV DNA was compared between first or recurrent episodes of eczema herpeticum and recurrent type herpes labialis. PATIENTS AND METHODS: Oral swabs were collected from 7 patients with eczema herpeticum and 9 with herpes labialis. The detection of oral HSV DNA was performed by the polymerase chain reaction method. RESULTS: Oral HSV DNA was detected in 6 out of 7 patients (86%) with eczema herpeticum and 3 of 9 (33%) with herpes labialis. CONCLUSIONS: The high frequency of oral HSV DNA detection in eczema herpeticum suggests that subclinical herpetic lesions may develop in the oral cavity of patients with a first episode of eczema herpeticum or may occur during asymptomatic oral HSV shedding in people with recurrent eczema herpeticum.
Close association of predominant genotype of herpes simplex virus type 1 with eczema herpeticum analyzed using restriction fragment length polymorphism of polymerase chain reaction.
Herpes simplex virus type 1 (HSV-1) strains belonging to the same genotype can possibly share biological properties and clinical manifestations common to the genotype. We classified previously 66 HSV-1 strains into 35 genotypes (F1-F35) using restriction fragment length polymorphism (RFLP) and F1 and F35 genotypes were revealed to be predominant [Arch. Virol. 13 (1993) 29]. It was found later that the F35 genotype seemed to be closely associated with eczema herpeticum [J. Med. Virol. 49 (1996) 329]. In the present study, a convenient method was developed for classification of two predominant genotypes by RFLP of polymerase chain reaction (RFLP-PCR). Using this method, genotypes of 21 strains isolated from eczema herpeticum were analyzed; seven of 21 strains (33.3%) were of F1 and five of 21 (23.8%) were of F35. Genotypes of 19 strains isolated from facial herpes other than eczema herpeticum were as follows; six of 19 (31.6%) strains were of F1 and one of 19 (5.3%) were of F35. Thus, strains belonging to F35 were appear to have been isolated more frequently from eczema herpeticum (5/21) than from facial herpes (1/19). These ratios showed a statistically significant difference. These results support the hypothesis that F35 strains is clearly associated with eczema herpeticum, in agreement with previous study. This is the first report of PCR-based approach for classification of HSV-1 strains into genotypes seeking an association of a genotype with clinical manifestation.
Analysis of numbers of repeated units in R2 region among varicella-zoster virus strains.
BACKGROUND: A variable region, R2, on the varicella-zoster virus (VZV) genome contains a repeated 42-bp unit. OBJECTIVE: The purpose of this study is the derivation of significance from tandem reiteration structure in the R2 region. METHODS: Fifty-two specimens were collected from 52 patients with herpes zoster in Osaka and Tokyo, Japan. After treatment of the specimens to release viral DNA, the samples were amplified directly by polymerase chain reaction. In addition, 14 samples were collected from 7 of these zoster patients after valaciclovir or aciclovir therapy. RESULTS: Analyses of the 52 specimens revealed that the number of repeats ranged from 4 to 13. Interestingly, the numbers of repeats among various VZV strains showed a normal distribution pattern, so that 6-9 repeats were found to be predominant in both Osaka (85%) and Tokyo (72%). The pre- and post-treatment strains taken from the same individuals showed the same numbers of repeats (7-9 in 6 cases and 11 in one). CONCLUSION: Our results suggest that the 6-9 repetitions of the 42-bp unit, with presumed stability, may offer these virus strains an advantage in virulence to human skin.
Radiosensitization by inhibition of IkappaB-alpha phosphorylation in human glioma cells.
To assess the role of nuclear factor kappaB (NFKB) in cellular radiosensitivity, three different IkappaB-alpha (also known as NFKBIA) expression plasmids, i.e., S-IkappaB (mutations at (32, 36)Ser), Y-IkappaB (a mutation at (42)Tyr), and SY-IkappaB, were constructed and introduced into human brain tumor M054 cells. The clones were named as M054-S8, M054-Y2 and M054-SY4, respectively. Compared to the parental cell line, M054-S8 and M054-Y2 cells were more sensitive to X rays while M054-SY4 cells exhibited the greatest sensitivity. After treatment with N-acetyl-Leu-Leu-norleucinal, a proteasome inhibitor, the X-ray sensitivity of M054-S8 and M054-SY4 cells did not change, while that of M054-Y2 cells and the parental cells was enhanced. An increase in X-ray sensitivity accompanied by a decrease in translocation of NFKB to the nucleus in parental cells was observed after treatment with pervanadate, an inhibitor of tyrosine phosphatase, as well as in M054-S8 and M054-SY4 cells. Repair of potentially lethal damage (PLD) was observed in the parental cells but not in the clones. Four hours after irradiation (8 Gy), the expression of TP53 and phospho-p53 ((15)Ser) was induced in the parental cells but not in M054-S8, M054-Y2 or M054-SY4 cells. Our data suggest that inhibition of IkappaB-alpha phosphorylation at serine or tyrosine acts independently in sensitizing cells to X rays. NFKB may play a role in determining radiosensitivity and PLD repair in malignant glioma cells; TP53 may also be involved.
[Herpes simplex virus infection].
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[Varicella-zoster virus infection].
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Exposure to power frequency magnetic fields suppresses X-ray-induced apoptosis transiently in Ku80-deficient xrs5 cells.
In an attempt to determine whether exposure to extremely low frequency (ELF) electromagnetic fields can affect cells, Ku80-deficient cells (xrs5) and Ku80-proficient cells (CHO-K1) were exposed to ELF electromagnetic fields. Cell survival, and the levels of the apoptosis-related genes p21, p53, phospho-p53 (Ser(15)), caspase-3 and the anti-apoptosis gene bcl-2 were determined in xrs5 and CHO-K1 cells following exposure to ELF electromagnetic fields and X-rays. It was found that exposure of xrs5 and CHO-K1 cells to 60 Hz ELF electromagnetic fields had no effect on cell survival, cell cycle distribution and protein expression. Exposure of xrs5 cells to 60 Hz ELF electromagnetic fields for 5 h after irradiation significantly inhibited G(1) cell cycle arrest induced by X-rays (1 Gy) and resulted in elevated bcl-2 expression. A significant decrease in the induction of p53, phospho-p53, caspase-3 and p21 proteins was observed in xrs5 cells when irradiation by X-rays (8 Gy) was followed by exposure to 5 mT ELF magnetic fields. Exposure of xrs5 cells to the ELF electromagnetic fields for 10 h following irradiation significantly decreased X-ray-induced apoptosis from about 1.7% to 0.7%. However, this effect was not found in CHO-K1 cells within 24 h of irradiation by X-rays alone and by X-rays combined with ELF electromagnetic fields. Exposure of xrs5 cells to 60 Hz ELF electromagnetic fields following irradiation can affect cell cycle distribution and transiently suppress apoptosis by decreasing the levels of caspase-3, p21, p53 and phospho-p53 and by increasing bcl-2 expression.
Schnitzler's syndrome with IgG kappa gammopathy.
A seventy-year-old man with a variant type of Schnitzler's syndrome is reported. Physical examination showed pruritic urticarial lesions on the extremities, arthralgia of knee joints, and intermittent fever. Laboratory investigations revealed a high level of IgG, an increased enythrocyte sedimentation rate, urinary Bence-Jones protein, and an M-bow in serum protein electrophoresis, which was shown to be a monoclonal IgG kappa type. Histological examination showed perivascular neutrophil and lymphocytic infiltration into the upper dermis and diffuse neutrophilic infiltration in the middle dermis. One of the clinical features of typical Schnitzler's syndrome is IgM macroglobulinemia, and this is a very rare case of this syndrome with IgG gammopathy.
Effects of exposure of CHO-K1 cells to a 10-T static magnetic field.
PURPOSE: To evaluate whether exposure to strong static magnetic fields (SMFs), of up to 10 T, affects the growth and cycle distribution of and the micronucleus formation in monolayered Chinese hamster ovary CHO-K1 cells. MATERIALS AND METHODS: The authors developed a system to expose cultured cells to strong SMFs immediately after the cells are seeded. Cell growth rate was evaluated according to cell number count. Cell cycle distribution experiments were performed by using flow cytometric analysis. In these experiments, the cells were exposed to SMFs for up to 4 days. The frequency of micronucleus formation with only SMF exposure at x-ray irradiation was analyzed at microscopic observation. RESULTS: Long-term exposure to a 10-T SMF for up to 4 days did not affect cell growth rate or cell cycle distribution. Exposure to SMFs alone did not affect micronucleus frequency. In x-ray-irradiated cells, exposure to a 1-T SMF did not affect micronucleus frequency, but exposure to a 10-T SMF resulted in a significant (P <.05) increase in micronucleus frequency. CONCLUSION: Strong (10-T) SMFs have no effect on cell growth, cell cycle distribution, or micronucleus frequency, but they may cause an increase in the micronucleus formation induced by 4-Gy x rays.