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Biomedical subjects

T Honda

Publications and source records attributed to T Honda.

At least 19 recordsLinked to original sources
PubMed2006

Nosocomial transmission of methicillin-resistant Staphylococcus aureus via the surfaces of the dental operatory.

OBJECTIVE: We assess the possibility of methicillin-resistant Staphylococcus aureus (MRSA) transmission via the surfaces of the dental operatory. METHODS: A survey of MRSA contamination on the surfaces of the dental operatory, and an analysis of MRSA transmission via the dental operatory between patients was carried out in the department of special dental care and oral surgery. RESULTS: MRSA was observed on the surfaces of dental operatory including the air-water syringe and reclining chair. Nosocomial infection or colonisation of MRSA occurred in eight out of 140 consecutive patients who had no evidence of MRSA at admission. Antibiograms of 30 antibiotics revealed that the isolates from the eight patients were of the same strain as those from the surface of dental operatory. After treating the patients under a revised infection control (IC) protocol including a single use of barrier covers, MRSA was not detected on the surfaces of the dental operatory, and no nosocomial infection or colonisation occurred during hospitalisation (0/117 patients). CONCLUSIONS: These results suggest that MRSA contaminates the surfaces of the dental operatory, and therefore the dental operatory should be considered a possible reservoir of MRSA.

Cross Infection↗
PubMed2006

Detailed images of asteroid 25143 Itokawa from Hayabusa.

Rendezvous of the Japanese spacecraft Hayabusa with the near-Earth asteroid 25143 Itokawa took place during the interval September through November 2005. The onboard camera imaged the solid surface of this tiny asteroid (535 meters by 294 meters by 209 meters) with a spatial resolution of 70 centimeters per pixel, revealing diverse surface morphologies. Unlike previously explored asteroids, the surface of Itokawa reveals both rough and smooth terrains. Craters generally show unclear morphologies. Numerous boulders on Itokawa's surface suggest a rubble-pile structure.

Journal Article↗
PubMed2006

Difference of HBV genotype distribution between acute hepatitis and chronic hepatitis in Japan.

BACKGROUND: Recently genotype A which is rare in the patients in chronic hepatitis B (CHB) was frequently noted in patients with acute hepatitis B (AHB). To investigate their clinical and virological features, we studied the AHB patients in the past 5 years. PATIENTS AND METHODS: 98 patients with AHB and 80 patients with CHB admitted to our hospital between 1998 and 2003 were studied. RESULTS: Genotype A was not found in CHB but was frequently noted in AHB (p < 0.001). Comparison of the clinical features of acute hepatitis between the two major genotypes, A and C, homosexual and heterosexual with multiple partners were frequently seen among genotype A patients (p < 0.001). On the other hand, infection from steady partner showed a tendency to be more frequent in genotype C (p = 0.065). In genotype A, the levels of HBVDNA on admission was higher (p = 0.007) and AHB has significantly more frequently progress to chronic infection than in genotype C (p = 0.028). Phylogenetic analysis of genotype A revealed that almost all strains from homosexual men belonged not to the African type A1 but to the Western type A2. CONCLUSION: Genotype A has increased recently among AHB in Japan. This fact may correlate to promiscuous intercourse in high risk group. Prophylactic efforts should be considered to prevent the prevailing of genotype A.

Acute Disease↗
PubMed2006

Promoter polymorphism in the macrophage migration inhibitory factor gene is associated with obesity.

OBJECTIVE: To explore the association of promoter polymorphisms of macrophage migration inhibitory factor (MIF) gene with obesity. SUBJECTS: In total, 213 nondiabetic Japanese subjects. They were divided into three groups according to World Health Organization definitions: lean (body mass index (BMI) <25 kg/m2), overweight (25 < or = BMI < 30 kg/m2) and obese (BMI> or = 30 kg/m2). METHODS: We examined two polymorphic loci in the MIF gene in the subjects: a single-nucleotide polymorphism at position -173 (G/C) and a CATT-tetranucleotide repeat polymorphism at position -794, which both can affect promoter activity in different cells. RESULTS: We detected four alleles: 5-, 6-, 7- and 8-CATT at position -794. Genotypes without the 5-CATT allele (X/X, X refers to 6-, 7- or 8-CATT alleles) were more common in obese subjects than in lean or overweight groups (P = 0.013). The X-CATT allele was more frequent in obese subjects than in lean or overweight subjects (P = 0.030). In contrast, -173G/C was not associated with obesity. Among the haplotypes of the two promoter polymorphisms, G/5-CATT ((-173G/C)/(-794[CATT](5-8))) was associated with a decreased risk of obesity (P = 0.025) and G/6-CATT with an increased risk of overweight (P=0.028). CONCLUSION: Promoter polymorphism in the MIF gene is linked with obesity.

Adult↗
PubMed2006

Balance of inflammatory response in stable gingivitis and progressive periodontitis lesions.

The balance between inflammatory mediators and their counter-regulatory molecules may be crucial for determining the outcome of immune pathology of periodontal diseases. Based on clinical and immunological findings, the immune response in stable gingivitis lesion is supposed to be in balance, whereas the response is skewed towards the predominance of proinflammatory reactivity in progressive periodontitis lesion. However, this hypothesis has not been verified. Therefore, the aim of this study was to compare the gene expression profile of inflammatory mediators including proinflammatory cytokines and other inflammatory molecules, and anti-inflammatory cytokines by using quantitative real-time polymerase chain reaction in gingivitis and periodontitis lesions showing distinct clinical entities. For inflammatory mediators, interleukin (IL)-1beta, interferon (IFN)-gamma and receptor activator of nuclear factor (NF)-kappaB ligand tended to be higher in periodontitis, whereas tumour necrosis factor (TNF)-alpha and IL-12 p40 showed no difference. Heat-shock protein 60 (HSP60) expression was up-regulated significantly in periodontitis. For anti-inflammatory cytokines, transforming growth factor (TGF)-beta1 expression tended to be higher in periodontitis compared with gingivitis, whereas no difference was observed for IL-10 and IL-4. These findings support further our previous finding that autoimmune response to HSP60 may exert in periodontitis lesion, and suggest that perhaps subtle differences in the balance of cytokines may result in different disease expression.

Adult↗
PubMed2006

Evaluation of genetic diversity in Japanese Brown cattle population by pedigree analysis.

The Japanese Brown is the second most common domestic beef breed in Japan. However, nowadays this breed is facing reduction in numbers because of pressure from a profitable domestic breed. This breed is uniformly characterized by its brown coat colour, but is comprised of two isolated sub-breeds, Kumamoto and Kouchi, each possessing a different gene pool. Pedigree analyses were carried out for the two sub-breeds using the pedigree records of animals born from 1970 to 2000. The effective population size has been found to be consistently reducing during the last three decades in both sub-breeds. The current effective sizes were estimated to be 25.5 and 6.0 for the Kumamoto and Kouchi sub-breeds, respectively. The estimate of the effective number of founders (N(ef)) in the Kumamoto sub-breed decreased from 152.1 to 74.4; that of non-founders (N(enf)), from 41.7 to 5.3; and that of founder genome equivalents (N(ge)), from 32.7 to 4.9. The corresponding changes in the Kouchi sub-breed were from 108.2 to 79.4, 16.2 to 4.1, and 14.1 to 3.9. Increasing differences between the two genetic diversity indices in the sub-breeds indicate that the greater part of the reduction of genetic diversity can be attributed to genetic drift that accumulated in the non-founder generations. A comparison with published estimates for several cattle breeds suggests the extremely limited genetic diversity of Japanese Brown. In addition to the avoidance of further reduction of genetic diversity, it will be important to counteract the process of breed decline by establishing a production system to efficiently utilize the unique characteristics of this breed and by developing links between the breed and products with market value.

Animals↗
PubMed2006

[Off-pump coronary artery bypass in high-risk patients].

In this study, 110 consecutive patients who had undergone off-pump coronary artery bypass (OPCAB) in the past 2 years were evaluated for early results of OPCAB. Patients were classified as a high-risk group (H group: 68 patients consisting of 46 men and 22 women) and a low-risk group (L group: 42 patients consisting of 31 men and 11 women), respectively, and were evaluated for the early operative results. No differences were noted between the H and L groups in the mean number of bypass grafts (2.9 +/- 0.9 in the H group, 2.9 +/- 0.9 in the L group), the rates of complete revascularization (85% in the H group, 93% in the L group), those of various graft materials bypassed, or those of sequential bypass. In all patients, we were able to undergo coronary revascularization by the aortic no-touch technique using arterial grafts exclusively. In the H group, 1 patient (1.5%) died in hospital, but no patients developed cerebral infarction postoperatively, and the frequency of complications was similar to that in the L group. The results of OPCAB for high-risk patients were good, and it was suggested that OPCAB using in situ arterial grafts was very useful particularly in patients with cerebrovascular diseases.

Aged↗
PubMed2005

RASSF2, a potential tumour suppressor, is silenced by CpG island hypermethylation in gastric cancer.

RASSF2, a member of the RASSF1 family, has recently been identified as a potential tumour suppressor. We examined methylation status in multiple regions which included the CpG island and spanned the transcription start site of RASSF2 in 10 gastric cancer cell lines, as well as 78 primary gastric cancers and corresponding non-neoplastic gastric epithelia. Hypermethylation of RASSF2 in at least one of the regions examined was detected in seven (70%) of the 10 cell lines; two (20%) exhibited hypermethylation in all the regions examined including the transcription start site and lost expression of RASSF2 mRNA, which could, however, be restored by 5-aza-2' deoxycytidine treatment, while the other five (50%) cell lines exhibited hypermethylation at the 5'- and/or 3'- edge, with four of them expressing RASSF2 mRNA. In primary gastric cancers and corresponding non-neoplastic gastric epithelia, frequencies of RASSF2 methylation ranged from 29% (23 out of 78) to 79% (62 out of 78) and 3% (two out of 78) to 60% (47 out of 78), respectively, at different CpG sites examined. Methylation was frequently observed at the 5'- and 3'- edges, and became less frequent near the transcription start site in both the primary gastric cancers and corresponding non-neoplastic gastric epithelia. Hypermethylation near the transcription start site was mostly cancer-specific. We thus showed that RASSF2 is silenced by hypermethylation near the transcription start site in gastric cancer. Hypermethylation was found initially to occur at the 5'- and 3'- furthest regions of the CpG island in non-neoplastic gastric epithelia, to gradually spreads near the transcription start site to shut down RASSF2 expression, and ultimately to constitute a field-defect placing tissue increased risk for development of gastric cancer.

Adult↗
PubMed2005

Cisplatin-incorporating polymeric micelles (NC-6004) can reduce nephrotoxicity and neurotoxicity of cisplatin in rats.

In spite of the clinical usefulness of cisplatin (CDDP), there are many occasions in which it is difficult to continue the administration of CDDP due to its nephrotoxicity and neurotoxicity. We examined the incorporation of CDDP into polymeric micelles to see if this allowed the resolution of these disadvantages. Cisplatin was incorporated into polymeric micelles through the polymer-metal complex formation between polyethylene glycol poly(glutamic acid) block copolymers and CDDP (NC-6004). The pharmacokinetics, pharmacodynamics, and toxicity studies of CDDP and NC-6004 were conducted in rats or mice. The particle size of NC-6004 was approximately 30 nm, with a narrow size distribution. In rats, the area under the curve and total body clearance values for NC-6004 were 65-fold and one-nineteenth the values for CDDP (P<0.001 and 0.01, respectively). In MKN-45-implanted mice, NC-6004 tended to show antitumour activity, which was comparable to or greater than that of CDDP. Histopathological and biochemical studies revealed that NC-6004 significantly inhibited the nephrotoxicity of CDDP. On the other hand, blood biochemistry revealed transient hepatotoxicity on day 7 after the administration of NC-6004. Furthermore, rats given CDDP showed a significant delay (P<0.05) in sensory nerve conduction velocity in their hind paws as compared with rats given NC-6004. Electron microscopy in rats given CDDP indicated the degeneration of the sciatic nerve, but these findings were not seen in rats given NC-6004. These results were presumably attributable to the significantly reduced accumulation of platinum in nerve tissue when NC-6004 was administered (P<0.05). NC-6004 preserved the antitumour activity of CDDP and reduced its nephrotoxicity and neurotoxicity, which would therefore seem to suggest that NC-6004 could allow the long-term administration of CDDP where caution against hepatic dysfunction must be exercised.

Animals↗
PubMed2005

Sensory nerve-dominant nerve degeneration and remodeling in the mutant mice lacking complex gangliosides.

Gangliosides, sialic acid-containing glycosphingo-lipids, are enriched in the mammalian nervous system. Since mutant mice with disrupted beta1,4-N-acetylgalactosaminyl-transferase (GM2/GD2 synthase) were generated, there have been several studies on the pathology of the mutant mice, i.e. mild functional disorders and Wallerian degeneration in the peripheral nervous system. To further analyze the chronological alteration in the mutant mice, we examined the peripheral and CNS mainly with morphological approaches, such as electron microscopy and immunohistochemistry. Accordingly with the sensory dysfunction, neural degeneration, glial proliferation and synaptic remodeling in the dorsal horn of the spinal cord were found in adult mice. Thick astrocytic processes with densely packed glial filaments were extended among the neuropils and around blood vessels. Morphological changes in the synaptic vesicles and modes of synaptic contacts with central terminals were detected, suggesting synaptic remodeling following the degeneration. These results suggest that complex gangliosides are essential in the maintenance of integrity in architecture and function of the nervous system, lack of which results in neural degeneration in a sensory nerve-dominant manner.

Age Factors↗
PubMed2005

A case of chondroma of the tongue.

Chondroma of the tongue represents a very rare benign tumor at this site, with very few reports of pure chondroma (no components of adipose, fibrous or bony tissue) existing. This report presents the case of a 17-year-old man with chondroma arising at the center of the tongue.

Adolescent↗
PubMed2005

Development of a simple method to evaluate medical staff radiation dose and its application to a software system supporting PET facility operation.

In recent years, positron-emitting labelled radiopharmaceuticals have come to be used in conjunction with positron emission tomography (PET) in various clinical diagnoses. Radiation exposure of the medical staff is a key issue in the design of PET facilities intended to handle large numbers of persons for PET diagnosis. As a first step, the radiation dose to individuals who received radiopharmaceuticals was calculated using a mathematical phantom model and the EGS4 electromagnetic cascade Monte Carlo code and MCNP Monte Carlo code. Dose rate behind a lead shield was also calculated for various lead thicknesses. The radiation dose distribution around a syringe containing a positron emitter was calculated. The calculated dose distributions were fitted to polynomial equations. These calculations were evaluated against measurements. The second step was to evaluate medical staff dose at a specified time by superimposing dose distribution from each person who received radioisotopes taking into account radioactive decay. In this way, we developed software to support PET facility operation, namely, planning, prediction, control of medical staff dose and facility operation. This system was also designed to schedule daily radiopharmaceuticals production and to manage radioactive wastes by taking decay time into account.

Body Burden↗
PubMed2005

Eradication of Helicobacter pylori increases platelet count in patients with idiopathic thrombocytopenic purpura in Japan.

BACKGROUND: The effect of Helicobacter pylori eradication on the platelet count in patients with thrombocytopenic purpura is controversial. In this multicentre study, we prospectively assessed the effect of H. pylori eradication therapy in idiopathic thrombocytopenic purpura patients. MATERIALS AND METHODS: Thirty-five consecutive patients with chronic idiopathic thrombocytopenic purpura (11 males and 24 females, a median age of 57) were assessed for H. pylori infection by use of a urea breath test. All patients received 1-week triple therapy (amoxicillin, clarithromycin, and lansoprazole) to eradicate H. pylori. At 6 months, idiopathic thrombocytopenic purpura patients with a platelet count recovery of greater than 100 x 10(9) L(-1) were defined as idiopathic thrombocytopenic purpura responders. RESULTS: Helicobacter pylori infection was observed in 25 (71%) of the 35 patients. All infected patients were cured. Eleven patients were identified as idiopathic thrombocytopenic purpura responders; 24 were considered nonresponders. Platelet counts improved by more than 100 x 10(9) L(-1) in 11 (44%) of the 25 patients cured of H. pylori infection, while none of the 10 patients H. pylori-negative patients experienced the same improvement (P = 0.015). Univariate analysis showed that H. pylori infection and its eradication were significant factors associated with platelet recovery (P = 0.015). CONCLUSIONS: Helicobacter pylori infection played a role in the pathogenesis of idiopathic thrombocytopenic purpura in approximately 30% of all patients assessed and 45% of the patients with H. pylori infection. Eradication of H. pylori in idiopathic thrombocytopenic purpura patients led to improved disease activity.

Adult↗
PubMed2005

Effects of Porphyromonas gingivalis antigens and proinflammatory cytokines on human coronary artery endothelial cells.

OBJECTIVE: Individuals with periodontitis have been cited as having a significantly increased risk of developing coronary heart disease. Although accumulating evidence suggests that periodontal infection is involved in the development and progression of atherosclerosis, the underlying mechanisms remain to be elucidated. In the present study, we examined how periodontal infection could contribute to endothelial dysfunction. METHODS: Human coronary arterial endothelial cells were stimulated with tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta, both of which are reported to be elevated in the serum of periodontitis patients. Cells were also stimulated with lipopolysaccharide, outer membrane protein and heat shock protein 60 derived from Porphyromonas gingivalis, a representative periodontopathic bacterium which is known to stimulate myeloid cells. RESULTS: Although TNF-alpha and IL-1beta, at concentrations a little higher than those in sera of periodontitis patients, up-regulated the expression of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1, P. gingivalis antigens had only a slight stimulatory effect. CONCLUSION: Experiments in which the total pathogen burden is considered, rather than a single species of bacteria, would increase our understanding of the contribution of which periodontal infection to atherogenesis.

Antigens, Bacterial↗
PubMed2005

Gene expression analysis of the CD4+ T-cell clones derived from gingival tissues of periodontitis patients.

The function of T cells infiltrating periodontitis lesions is complex and has not been fully elucidated. Here, we established T-cell clones from the gingival tissues of periodontitis patients and examined their gene expression. A total of 57 and 101 T-cell clones were established by means of immobilized anti-CD3 antibody and IL-2 from gingival tissues and peripheral blood, respectively. The gingival T-cell clones were derived from three patients, and the peripheral blood T-cell clones from two of these patients and a further patient whose gingival T-cell clones were not established. Gingival tissues were also obtained from a further 19 periodontitis patients. The expression of cytokines and molecules related to both regulatory function and tissue destruction were examined by means of reverse-transcription polymerase chain reaction. All the gingival T-cell clones expressed mRNA for TGF-beta1, CTLA-4, and CD25, and all the T-cell clones from peripheral blood expressed IFN-gamma and TGF-beta1 mRNAs. Most but not all the T-cell clones from gingival tissues and peripheral blood expressed mRNA for IFN-gamma and, CD25 and CTLA-4, respectively. The frequency of T-cell clones and gingival tissues expressing FOXP3, a possible master gene for mouse CD4(+)CD25(+) regulatory T cells, was very high (97%, 93%, and 100% for gingival T-cell clones, peripheral blood T-cell clones, and gingival tissues, respectively). Whereas the frequency of IL-4-expressing T-cell clones was lower for gingival T-cell clones (70% vs. 87%), the frequency of the gingival T-cell clones expressing IL-10 and IL-17 was higher than peripheral blood T-cell clones (75% vs. 62% for IL-10, 51% vs. 11% for IL-17). A similar expression profile was observed for gingival T-cell clones compared with gingival tissue samples with the exception of IL-4 expression, where the frequency of positive samples was lower in the gingival tissues (70% vs. 11%). These results suggest that the individual T cells infiltrating gingival lesions can express mRNA for both Th1 and Th2 cytokines as well as regulatory cytokines simultaneously.

Antigens, CD↗