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Niigata-shi, Japan

The anteroventral third ventricular region (AV3V) is a pivotal area for osmotic responses and integration of autonomic functions. The purpose of this study was to investigate whether the gamma-aminobutyric acid (GABA)-ergic activity in the AV3V may be involved in the regulation of arginine vasopressin (AVP) secretion and related phenomena under the conditions with or without hypovolemia. Experiments were performed in conscious rats. We found that AV3V infusion with the GABA A receptor antagonist bicuculline in euvolemic rats caused prompt increases in plasma AVP, osmolality, glucose, arterial pressure and heart rate. The effects of the bicuculline infusion were abolished by prior infusion of a GABA A receptor agonist, muscimol. When repeated twice with a 10-min interval, removal of systemic blood (10 mL/ kg body weight) lowered arterial pressure and enhanced plasma AVP, osmolality, glucose and angiotensin II. Muscimol infusion in the AV3V, but not in the cerebral ventricle, inhibited the responses of plasma AVP and glucose, despite having no effect in a sham hemorrhagic state. The inhibition of the AVP response by the muscimol infusion was also verified in rats given a combined stimulus of bleeding plus an osmotic load. In contrast, AV3V infusion with the GABA B receptor agonist baclofen tended to intensify the hemorrhagic responses of plasma AVP and glucose, despite its potency to prevent the hemorrhagic fall in arterial pressure. These results, taken together with our previous data, suggest that hypovolemic stimuli, like hyperosmotic stimuli, may promote AVP secretion by causing the inhibition of AV3V GABA A-ergic activity responsible for potentiation of glutamatergic activity. © The Japan Endocrine Society.

Maruyama K.,Niigata Seiryo University | Yorifuji T.,Okayama University of Science | Tsuda T.,Okayama University of Science | Sekikawa T.,Nuttari Clinic | And 2 more authors.
Journal of Biomedicine and Biotechnology | Year: 2012

Background. Large-scale poisonings caused by methyl mercury (MeHg) have occurred in Japan (Minamata in the 1950s and Niigata in the 1960s) and Iraq (in the 1970s). The current WHO neurological risk standard for adult exposure (hair level: 50g/g) was based partly on evidence from Niigata which did not consider any cases who were diagnosed later and/or exposed to low level of MeHg (hair mercury level less than 50g/g). Methods. Early in the Niigata epidemic in June 1965 there were two extensive surveys. From these two surveys, we examined 103 adults with hair mercury measurement who consulted two medical institutions. We compared the prevalence and the distribution of neurological signs related to MeHg poisoning between exposure categories. Result. We found 48 subjects with neurological signs related to MeHg poisoning who had hair mercury concentration less than 50g/g. Among the neurological signs, sensory disturbance of the bilateral distal extremities was observed more frequently, followed by disequilibrium, hearing impairment, and ataxia, in groups with hair MeHg concentration both below 50g/g and over 50g/g. Conclusion. The present study suggests the possibility that exposure to MeHg at levels below the current WHO limits could cause neurologic signs, in particular, sensory disturbance. © Copyright 2012 Kimio Maruyama et al.

Abe T.,Niigata University | Aoki T.,Niigata University | Yata S.,Kido Hospital | Okada M.,Niigata University
Atherosclerosis | Year: 2011

Background: Previous studies have indicated that sleep duration is associated with total mortality in a U-shaped fashion. The purpose of the current study was to examine the relationship between self-reported sleep duration and carotid artery atherosclerosis in a Japanese population. Methods: In 2009-2010, a total of 2498 participants (1195 men, 1303 women; age range, 23-92. years) were recruited from members of a Japanese community receiving annual health check-up at a local health center who agreed to participate in the study. Exclusion criteria were as follows: age <40 or ≥85. years; and more than one missing value from either laboratory data or questionnaire responses. A total of 2214 participants were entered into the study. Carotid artery arteriosclerosis was evaluated ultrasonographically and quantified as intima-medial thickness (IMT). The presence of carotid artery atherosclerosis was defined as IMT ≥ 1.2. mm. Sleep durations were compared with IMT measurements after controlling for confounding factors such as age, sex, lipid profile, fasting plasma glucose, hemoglobin A1c, blood pressure, alcohol intake, and smoking habit. Results: Sleep duration ≥7. h correlated significantly with the incidence of IMT ≥ 1.2. mm when compared with a sleep duration of 6. h (multivariate-adjusted odds ratio, 1.263; 95% confidence interval, 1.031-1.546, P = 0.024). Shorter sleep duration ≤5. h did not correlate significantly with the risk compared with a sleep duration of 6. h. Conclusion: Long sleep duration (≥7. h) correlated significantly with the incidence of carotid artery atherosclerosis compared with a sleep duration of 6. h, but shorter sleep duration did not. © 2011 Elsevier Ireland Ltd.

Hara N.,Niigata University | Saito H.,Kido Hospital | Takahashi K.,Niigata University | Takeda M.,Yamanashi University
International Journal of Urology | Year: 2013

Objectives: To clarify the prevalence of lower urinary tract symptoms and overactive bladder in patients with chronic methyl mercury poisoning. Methods: A total of 151 patients (61 men and 90 women; mean age 72.1 years) with Niigata Minamata disease were enrolled. An age- and sex-matched group of 150 participants was used as control. Patients reported their International Prostate Symptom Score and overactive bladder symptom score. Results: In men, the total, storage and voiding International Prostate Symptom Score scores were higher in the Niigata Minamata disease group than in the control group (10.6±7.8 vs 5.0±5.0, 4.5±3.3 vs 2.4±2.4 and 6.1±5.1 vs 2.7±3.1, respectively, P<0.001 in all). In women, these scores were also higher in the Niigata Minamata disease group than in the control group (8.9±7.3 vs 4.0±4.0, 4.4±3.2 vs 2.8±2.4 and 4.5±5.0 vs 1.3±2.0, respectively, P<0.001 in all). The prevalence of overactive bladder was more frequent in the Niigata Minamata disease group compared with that in the control group (51.7% vs 26.7%, P<0.001). In both men and women, the overactive bladder symptom score was higher in the Niigata Minamata disease group than in the control group (4.1±3.0 vs 2.4±2.9, P=0.002 and 4.6±3.6 vs 2.7±2.9, P<0.001, respectively). The International Prostate Symptom Score and overactive bladder symptom score in the Niigata Minamata disease group were highest in patients aged 60-69 years (P<0.001 in both), whereas these increased in an age-dependent manner in the control group. Conclusions: Lower urinary tract symptoms and overactive bladder are severe and highly prevalent conditions among patients with methyl mercury poisoning. The higher prevalence of lower urinary tract symptoms among patients aged 60-69 years might be related to the fact that they were exposed to methyl mercury during their childhood/development. © 2012 The Japanese Urological Association.

Hokari S.,Niigata University | Tsukada H.,Niigata City General Hospital | Ito K.,Kido Hospital | Shibuya H.,Niigata City General Hospital
Internal Medicine | Year: 2010

A 58-year-old woman with an 18-year history of primary biliary cirrhosis was admitted because of pneumococcal pneumonia. She was treated with antibiotics and mechanical ventilation. After the pneumonia improved, she developed severe watery diarrhea. Although vancomycin was administered enterally, the diarrhea persisted. She died of multiple organ failure within 16 days of the onset of diarrhea. An autopsy showed intracapillary cryptococci in the systemic organs, especially in the intestinal tract. The cause of diarrhea was considered to be extensive intestinal mucosal necrosis due to disseminated cryptococcosis. This is a rare case of cryptococcal infection manifesting as acute diarrhea. © 2010 The Japanese Society of Internal Medicine.

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