Search PubMed⌕ Search

Biomedical subjects

M Okamoto

Publications and source records attributed to M Okamoto.

At least 55 records · Page 3Linked to original sources

High expression of interleukin-1beta in the corneal epithelium of MRL/lpr mice is under the control of their genetic background.

MRL/Mp mice bearing the Fas deletion mutant gene, lpr (MRL/lpr), spontaneously develop polyarthritis, sialoadenitis and dacryoadenitis, resembling rheumatoid arthritis (RA), and also corneal involvement such as keratopathy and scleritis, which is a major complication in RA patients. In this study, we found that the expression levels of IL-1beta and MMP-1 mRNAs in cornea were high in both MRL/lpr and MRL/Mp-+/+ strains of mice at an age younger than when they develop any inflammatory lesions. This was not true of other inbred strains, even those bearing the lpr gene, and also not of (NZB x NZW) F1 lupus mice. There was no significant difference in the expression of IL-1alpha and TGFbeta in cornea in these strains. Using crosses between MRL/lpr and C3H/HeJ-lpr/lpr (C3H/lpr) mice, at least the expression of IL-1beta was found to be under the control of the MRL genetic background, likely with a recessive mode of inheritance. Considering that IL-1beta in cornea was detected particularly in the epithelial layer, the high expression of IL-1beta in cornea is most likely involved in the genetic predisposition for corneal involvement and possibly also for arthritis in an MRL strain of mice.

Animals↗

An autopsy case of bacterial septic shock 12 years following ABO-incompatible renal transplantation.

We report the case of an ABO-incompatible kidney transplant recipient who died suddenly following a good transplant course of 12 years. For 10 years after transplantation, the graft function had been stable (s-Cr: 1.0-1.5 mg/dL), although chronic hepatitis C had developed, with elevation of transaminase. In the 11th year, he was admitted into the hospital with low-grade fever and general fatigue. Jaundice and anaemia progressed, and he died 2 months after admission. The autopsy diagnosis was: (1) post-renal transplantation state, (2) phlegmonous enterocolitis with septic infarction, (3) cellulitis and necrotic myositis, and (4) sepsis. The transplanted kidney graft showed well-preserved glomeruli and tubules, corresponding to chronic allograft nephropathy (CAN) grade Iota (ci1, ct1, cv1), according to the Banff classification. The pathological changes observed in this long-surviving ABO-incompatible kidney graft were similar to those of an ABO-compatible graft, although its degree was milder.

ABO Blood-Group System↗

Incidence and recurrence rates of colorectal adenomas estimated by annually repeated colonoscopies on asymptomatic Japanese.

BACKGROUND: Whereas high recurrence rates of colorectal adenomas after polypectomy are widely recognised, little is known of the natural incidence in those with no neoplastic lesions initially. It is also known that single colonoscopy has a significant miss rate. AIMS: To elucidate the incidence and recurrence rates of colorectal neoplasms from a large cohort of asymptomatic Japanese patients on the basis of annually repeated colonoscopies. METHODS: A total of 6225 subjects (4659 men and 1566 women) participating in an annual colonoscopic screening programme and completing three or more colonoscopies were analysed during the 14 year period between 1988 and 2002. Patients were divided into three groups according to the findings of the initial two colonoscopies: 4084 subjects with no neoplasm, 1818 with small adenomas <10 mm, and 323 with advanced lesions, including carcinoma in situ, severe dysplasia, or large adenomas > or =10 mm. Mean age at the second colonoscopy was 48.8 years. RESULTS: For all types of colorectal neoplasms, the incidence rate in those with no initial neoplasm was 7.2%/year whereas recurrence rates in those with small adenomas and advanced lesions were 19.3% and 22.9%/year, respectively. For advanced colorectal lesions, the incidence rate was 0.21%/year whereas recurrence rates in those with small adenomas and advanced lesions were 0.64% and 1.88%/year, respectively. Colorectal neoplasms were in general more likely to develop in males and older subjects. CONCLUSIONS: Although recurrence rates after polypectomy were elevated, the incidence rates in subjects with no neoplastic lesions initially were quite high.

Adenoma↗

Soft palate movement during sucking behavior.

To clarify the aspects and role of oropharyngeal closure, soft palate movements during sucking were observed and then assessed by electromyographic and fluoroscopic analyses. Three patterns of sucking movements by the palatoglossus and levator veli palatini muscles were analyzed with electromyographic means in seven healthy adults. Furthermore, a forced sucking maneuver, which required special effort to produce a strong sucking pressure by opening the jaw, was analyzed using lateral fluoroscopy in three of the subjects. During all tested sucking movements, the palatoglossus muscle showed continuous activity. The levator veli palatini muscle did not show remarkable activity during regular air sucking or water sucking when water was held in the oral cavity. However, its participation increased when intraoral sucking pressure was increased by opening the jaw, and lateral fluoroscopic examinations revealed that the soft palate was pulled toward the oral cavity to form a tight contact between the rostral portion of the soft palate and the retrotongue, causing the soft palate to make an "L" shape. The palatoglossus muscle plays a major role in palatal movement during sucking. Furthermore, the levator veli palatini muscle, whose activity was observed only during high-pressure sucking with an open jaw, may act to maintain tension in the soft palate against strong negative pressure in the oral cavity.

Adult↗

Experimental vertical transmission of Borna disease virus in the mouse.

We demonstrated the experimental vertical transmission of Borna disease virus (BDV) in pregnant BALB/c mice. Giessen strain He/80 of BDV was used in the present study. Six six-week-old mice were inoculated intraperitoneally with 10(5) 50% tissue culture infective doses (TCID50), and were bred immediately. Four pregnant mice were sacrificed under anaesthesia on the 10th and 14th days after vaginal plug formation. Nine newborns from two maternal mice were sacrificed under anaesthesia on the 7th day after birth. Positive signals with RT-nested PCR techniques for BDV p24-RNAs were seen in the fetuses, placentas and brains of all newborn mice. No immunopositivities for BDV p40 were found in the fetuses or placentas at 10 days' gestation. BDV p40 immunopositivities were found in neurons of the fetal brains and in decidual cells of the placentas at 14 days' gestation. They were also found in neurons of the brains of newborn mice. At 10 days' gestation, no positive signals for BDV p40 sense or antisense riboprobes were seen in the fetal brains or placentas. Positive signals were found in neurons of the fetal brains and decidual cells of the placentas at 14 days' gestation. Positive signals for BDV p40 sense and antisense riboprobes were found in almost all neurons throughout the brains of nine newborn mice. These results suggest that persistent infection with BDV in newborn mice may be induced by vertical transmission during gestation.

Animals↗

Serum uric acid and risk for development of hypertension and impaired fasting glucose or Type II diabetes in Japanese male office workers.

We examined the association of serum uric acid (SUA) with development of hypertension (blood pressure > or = 140/90 mmHg and/or medication for hypertension) and impaired fasting glucose (IFG) (a fasting plasma glucose level 6.1-6.9 mmol/l) or Type II (non-insulin-dependent) diabetes (a fasting plasma glucose level > or = 7.0 mmol/l and/or medication for diabetes) over a 6-year follow-up among 2310 Japanese male office workers aged 35-59 years who did not have hypertension, IFG, Type II diabetes, or past history of cardiovascular disease at study entry. After controlling for potential predictors of hypertension and diabetes, the relative risk for hypertension compared with quintile 1 of SUA level was 1.27 [95% confidence interval (CI): 1.00-1.62] for quintile 2, 1.34 (95% CI: 1.08-1.74) for quintile 3, 1.48 (95% CI: 1.18-1.89) for quintile 4, and 1.58 (95% CI: 1.26-1.99) for quintile 5 (p for trend <0.001). The respective multivariate-adjusted relative risks for IFG or Type II diabetes compared with quintile 1 of SUA level were 1.55 (95% CI: 0.95-2.63), 1.62 (95% CI: 0.98-2.67), 1.61 (95% CI: 1.01-2.58), and 1.78 (95% CI: 1.11-2.85) (p for trend = 0.030). The association between SUA level and risk for hypertension and IFG or Type II diabetes was stronger among men with a body mass index (BMI) <24.2 kg/m2 than among men with a BMI > or = 24.2 kg/m2, although the absolute risk was greater in more obese men. These results indicate that SUA level is closely associated with an increased risk for hypertension and IFG or Type II diabetes.

Adult↗

Inhibitory effects of green tea catechins on protein tyrosine phosphatase in Prevotella intermedia.

Members of the Prevotella intermedia group possess protein tyrosine phosphatase (PTPase). The purpose of this study was to investigate the effects of catechin derivatives from Japanese green tea on the activity of PTPase in P. intermedia and related organisms. Multilocus enzyme electrophoresis of alkaline phosphatase derived from P. intermedia, Prevotella nigrescens, Prevotella pallens and Porphyromonas gingivalis revealed a species-specific migration pattern. Among the tea catechin derivatives tested, (-)-epigallocatechin gallate (EGCg), similar to orthovanadate, a specific inhibitor for PTPase, was effective in inhibiting the PTPase activity in P. intermedia at 0.5 microm, and related species at 5 microm. The results suggested that the inhibitory effect observed is due to the presence of galloyl moiety in the structure. In contrast, neither the green tea catechins nor orthovanadate inhibited the phosphatase activity in P. gingivalis, suggesting that this organism possessed a different family of alkaline phosphatase.

Bacterial Proteins↗

Association of alcohol consumption with white blood cell count: a study of Japanese male office workers.

OBJECTIVES: To investigate the association of alcohol consumption with white blood cell (WBC) count. DESIGN: Cross-sectional study. SETTING: A work site in Japan. SUBJECTS: A total of 5218 Japanese male office workers aged 23-59 years who participated in annual health examinations. MAIN OUTCOME MEASURES: Subjects were classified as nondrinkers, or current drinkers who averaged <12, 12-22, 23-34, 35-45, 46-68 or > or = 69 g day(-1) of ethanol. The association between alcohol consumption and WBC count was examined by smoking status. RESULTS: After controlling for age, body mass index, systolic blood pressure, and levels of total cholesterol, high-density lipoprotein (HDL) cholesterol and fasting plasma glucose, WBC count showed a negative dose-response relation with alcohol consumption in each smoking status. The WBC count increment per category of alcohol intake (x10(9) cells L(-1)) was -0.07 [95% confidence interval (CI), -0.11 to -0.04] for never smokers, -0.11 (95% CI, -0.15 to -0.06) for ex-smokers, and -0.04 (-0.08 to -0.00) for current smokers. For current smokers, additional adjustment for cigarettes smoked per day heightened the magnitude of these associations [the respective WBC count increment (x10(9) cells L(-1)), -0.07 (95% CI, -0.11 to -0.03)]. The risk for high WBC count (fifth quintile) also showed a negative linear trend related to alcohol intake in each smoking status. CONCLUSIONS: The WBC count was inversely associated with alcohol consumption in both nonsmokers and smokers. In view of the firm association of WBC count with the increased risk of coronary heart disease, alcohol consumption seems to have a favourable impact on the link between WBC count and the risk of cardiovascular disease.

Adult↗