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Biomedical subjects

S Yamazaki

Publications and source records attributed to S Yamazaki.

At least 19 recordsLinked to original sources
PubMed2006

Symptoms of depression, prescription of benzodiazepines, and the risk of death in hemodialysis patients in Japan.

Many hemodialysis patients in Japan have symptoms of depression, but whether those patients are treated appropriately is unknown. As part of the Dialysis Outcomes and Practice Patterns Study, data on symptoms of depression, physician-diagnosed depression, prescribed medications, and death were collected prospectively in cohorts in Japan (n=1603) and 11 other countries (n=5872). Symptoms of depression were as prevalent in Japan as elsewhere, but in Japan a much smaller percentage of patients had physician-diagnosed depression: only 2% in Japan vs 17% elsewhere. Antidepressants were much less commonly prescribed in Japan: only 1% in Japan vs 17% elsewhere for patients with many and frequent symptoms of depression, and 16% in Japan vs 34% elsewhere for patients with physician-diagnosed depression. In Japan, symptoms of depression were associated with prescription of benzodiazepines (without antidepressants), and patients with physician-diagnosed depression were twice as likely to be given benzodiazepines: 32% in Japan vs 16% elsewhere. Benzodiazepine monotherapy was associated with death (relative risk 1.56, 95% confidence interval (CI), 1.25-1.94), even after adjustments for 13 likely confounders (relative risk 1.27, 95% CI, 1.01-1.59). Hemodialysis patients in Japan with symptoms of depression are given not antidepressants but benzodiazepines, a practice associated with higher mortality.

Anti-Anxiety Agents↗
PubMed2006

Intracerebral haemorrhage associated with hourly concentration of ambient particulate matter: case-crossover analysis.

AIMS: To examine the association of hourly time lagged concentration of ambient particulate matter and death due to stroke. METHODS: Mortality data for five years (January 1990 to December 1994) were obtained from the Ministry of Health, Labour, and Welfare of Japan. Data were used only if the deceased was 65 years old or older at the time of death, if death was attributed to intracerebral haemorrhage or ischaemic stroke, and if the deceased lived in one of 13 major urban areas. Hourly mean concentrations of PM7, NO2, and photochemical oxidants were measured at monitoring stations in the 13 areas. Time stratified case-crossover analysis was used to examine the data for evidence of triggering stroke mortality. RESULTS: The 1-hour mean concentration of PM7 measured about 2 hours before death was associated with the risk of death due to intracerebral haemorrhage from April to September (odds ratio = 2.40, 95% CI 1.48 to 3.89, for exposure to PM7 of more than 200 microg/m3 (threshold)). The higher risk was independent of the 24-hour mean concentration of PM7. PM7 was not associated with death due to ischaemic stroke. CONCLUSIONS: Transiently high concentrations of PM7 are associated with death due to intracerebral haemorrhage. Air quality standards or guidelines for particulate matter should be based not only on 24-hour mean concentrations, but also on hourly data.

Aged↗
PubMed2006

Insulin resistance and impaired myocardial fatty acid metabolism in dialysis patients with normal coronary arteries.

We investigated whether insulin resistance is associated with impaired cardiac fatty acid metabolism in maintenance hemodialysis patients without coronary artery disease. We studied 55 nondiabetic (63+/-11 years old) and 51 diabetic (61+/-10 years old) hemodialysis patients with normal coronary arteries, using single-photon emission computed tomography (SPECT) with an iodinated fatty acid analogue, iodine-123-beta-methyl iodophenyl-pentadecanoic acid ((123)I-BMIPP), to evaluate cardiac fatty acid metabolism. SPECT imaging was graded regionally from 0 (normal) to 4 (absence of tracer) to calculate a summed score for 17 left ventricular segments. Insulin resistance was determined using the homeostasis model assessment index of insulin resistance (HOMA-IR). HOMA-IR correlated with summed BMIPP score in nondiabetic and diabetic patients. Stepwise multiple regression analysis showed that HOMA-IR was independently associated with BMIPP summed score in nondiabetic (beta=0.774, t=9.218, P=0.0001) and diabetic patients (beta=0.792, t=9.079, P=0.0001). Left ventricular ejection fraction was lower in nondiabetic subjects with BMIPP summed score of at least 6 plus HOMA-IR of at least 4 than in others with lower values for both assessments (53.1+/-13.8%, n=20 vs 67.7+/-9.1%, n=23, P=0.0002); this was also true in diabetic subjects (50.9+/-15.2%, n=24 vs 71.0+/-13.6%, n=11, P=0.0007). Association between insulin resistance and impaired cardiac fatty acid metabolism may contribute to left ventricular dysfunction in patients with maintenance hemodialysis without coronary diseases.

Aged↗
PubMed2006

Low strength wastewater treatment under low temperature conditions by a novel sulfur redox action process.

The objective of this research is to make a novel wastewater treatment process activated by a sulfur-redox cycle action of microbes in low temperature conditions. This action is carried out by sulfate-reducing bacteria (SRB) and sulfur-oxidizing bacteria (SOB). The process was comprised of a UASB reactor as pre-treatment and an aerobic downflow hanging sponge (DHS) reactor as post-treatment. As the results of reactor operation, the whole process achieved that over 90% of CODcr removal efficiency, less than 30 mgCODcr/L (less than 15 mgBOD/L) of final effluent, at 12 h of HRT and at 8 degrees C of UASB reactor temperature. Acetobacterium sp. was detected as the predominant species by PCR-DGGE method targeting 16SrDNA with band excision and sequence analysis. In the UASB reactor, various species of sulfate-reducing bacterium, Desulfobulbus sp., Desulfovibrio sp., and Desulfomicrobium sp., were found by cloning analysis. In the DHS reactor, Tetracoccus sp. presented as dominant. The proposed sulfur-redox action process was considered as an applicable process for low strength wastewater treatment in low temperature conditions.

Bioreactors↗
PubMed2005

Household income is strongly associated with health-related quality of life among Japanese men but not women.

OBJECTIVES: As socio-economic status (SES) strongly reflects individual economic status, evaluating the association between SES and health could provide information that is important for planning integrated economic and public health policies. We examined the association between annual household income as a measure of SES and the eight scale scores of the Medical Outcomes Study Short Form-36 Health Survey (SF-36) as a quantifier of health-related quality of life (HRQOL) in Japan. STUDY DESIGN: Cross-sectional survey. METHODS: Data were from the SF-36 national survey in Japan. A total of 4500 people aged 16 years or older were selected from the entire population of Japan using stratified-random sampling, and 3395 responded to the survey. RESULTS: Men with lower levels of annual household income had lower scores in all SF-36 domains. However, only 'general health perceptions' and 'social functioning' showed statistically significant trends among the women surveyed. In the subgroup of women working full-time, there were no domains that showed significant trends. CONCLUSIONS: A strong association exists between annual household income and SF-36 scores among men, but there is only a limited association among women. The employment and economic policies that affect annual household income potentially influence HRQOL.

Adult↗
PubMed2005

Tetraparesis due to exostotic osteochondroma at upper cervical cord in a patient with multiple exostoses-mental retardation syndrome (Langer-Giedion syndrome).

STUDY DESIGN: Case report of a severe upper cervical cord compression and tetraparesis by a massive cervical exostotic osteochondroma in a patient with multiple exostoses-mental retardation syndrome (Langer-Giedion syndrome; LGS). OBJECTIVE: To describe this very rare pathological condition and the results of surgical intervention. SETTING: Gifu, Japan. METHODS: A 23-year-old man was referred to our clinic because of progressing tetraparesis. He had previously been diagnosed with hereditary multiple exostoses and mental retardation. As he had not complained of any symptoms, his family only noticed the tetraparesis after advanced deterioration. His face possessed the pathognomic features of LGS. A postmyelogram CT scan demonstrated an exostotic mass arising from the left-side C2 pedicle with associated severe spinal cord compression. He was diagnosed with LGS. Hemilaminectomy on the left side and resection of the osteochondroma were performed. RESULTS: At 5 years postoperatively, a neurological examination showed the full return of all motor functions. The CT scan revealed no intracanalar recurrence of the tumor. CONCLUSION: In this case of severe tetraparesis due to cervical osteochondroma, decompression by hemilaminectomy provided excellent results. In patients with LGS and intracanalar osteochondroma, the neurological deficit may be masked by mental retardation. Hence, awareness of this pathological condition will help clinicians diagnose it at an early stage.

Adult↗
PubMed2005

[Thoracoscopy and intraoperative upper gastrointestinal endoscopy was effective for Boerhaave syndrome; report of a case].

Boerhaave syndrome is a rare disease and needs an exact diagnosis and a proper treatment plan because of its terrible clinical course. We experienced a case of Boerhaave syndrome that thoracoscopy and intraoperative upper gastrointestinal (GI) endoscopy was very effective. Sixty-four-year-old man realized chest and back pain after vomitting. Esophageal perforation was suspected, but 64 hours had passed already when we started a surgical treatment. By the thoracoscopy and intraoperative endoscopy, lower esophageal perforation and infectious pleural effusion were found. Therefore, we selected a surgical treatment under the assistance of thoracoscopy. Secondly, a simple closure and intracostal muscle overlapping was performed with small incisional thoracotomy. Postoperative complication, such as mediastinal abscess, has not occurred. Thoracoscopy and intraoperative upper GI endoscopy was effective for an appropriate diagnosis and treatment of Boerhaave syndrome.

Endoscopy, Gastrointestinal↗
PubMed2004

The herbal medicine Rikkunshi-to stimulates and coordinates the gastric myoelectric activity in post-operative dyspeptic children after gastrointestinal surgery.

Rikkunshi-to (TJ-43), a gastroprotective herbal medicine, has been used for the symptomatic relief of adult patients with dyspepsia. However, its mechanism has yet to be fully elucidated. The aim of this study is to evaluate the effect of TJ-43 on the gastric myoelectric activity in post-operative dyspeptic patients, whose symptoms persisted for over 1 year after gastrointestinal surgery. Electrogastrography (EGG) recordings were performed to calculate the biomechanical parameters on the dominant peak frequency (DPF). Eight pediatric patients with dyspeptic symptoms after gastrointestinal surgery were examined and six age-matched children without any dyspeptic symptoms were used as controls, and they were compared with nine age-matched children without any dyspeptic symptoms after gastrointestinal surgery as subcontrols. All patients exhibited symptomatic relief after the administration of TJ-43, and the mean symptom score decreased significantly after the treatment of TJ-43 over a 1-month period ( P<0.0001). The variability index (VI) and the percentage of normal waves (PNW) were calculated as irregularity parameters of DPF. The power ratio (PR) was calculated as a parameter of the gastric contractile activity. There were no significant differences in the VI and PNW between the controls and patients during the postprandial state after therapy, even though significant differences existed regarding those parameters between the controls and patients before the therapy. There were no significant differences in the DPF, VI, and PNW between the controls and subcontrols. Furthermore, PR exhibited a significant increase after therapy ( P<0.05). However, there was a significant difference in the PR between the controls and subcontrols ( P<0.05). Postprandial dip was observed in all control subjects, eight patients in the subcontrols, and two patients after administration of TJ-43, respectively. An abnormal gastric electrical activity therefore seems to be an important factor in the pathophysiology of post-operative dyspeptic children. The coordinating and stimulating effect of TJ-43 on the gastric myoelectric activity therefore seems to play an important role in the reduction of dyspeptic symptoms.

Adolescent↗
PubMed2004

Increased prevalence of human parvovirus B19 DNA in systemic sclerosis skin.

BACKGROUND: Human parvovirus B19 is a small, single-stranded DNA virus encoding two structural capsid proteins and a nonstructural protein. It is the aetiological agent of erythema infectiosum and transient aplastic crisis in patients with haemolytic anaemia, and has been associated with fetal death, arthritis and chronic anaemia. In recent years, the possible involvement of parvovirus B19 in systemic sclerosis (SSc) has been reported. OBJECTIVES: To determine whether human parvovirus B19 DNA can be detected in SSc skin tissue specimens. METHODS: Normal subjects (n = 97) and patients with SSc (n = 48), systemic lupus erythematosus (n = 16), dermatomyositis (n = 8), morphoea (n = 6) and graft-versus-host disease (n = 8) were studied. Crude DNA was extracted from skin tissue specimens. We attempted to determine whether human parvovirus B19 could be detected in the skin of SSc using nested polymerase chain reaction (PCR). PCR amplification was performed with specifically designed first and second primer pairs for parvovirus B19 DNA. RESULTS: After the first PCR, the occurrence rate of parvovirus B19 DNA in SSc skin tissues (36 of 48, 75%) was significantly elevated in comparison with that in normal controls (50 of 97, 52%) (P < 0.01). After the second PCR, the occurrence rate of parvovirus B19 DNA in SSc skin tissues (36 of 48, 75%) was significantly elevated compared with that in normal controls (53 of 97, 55%) (P < 0.02). The occurrence rates in the other diseases showed no significant difference from that in normal controls. CONCLUSIONS: The increased prevalence of human parvovirus B19 DNA in SSc skin showed the possibility that the virus may be involved in the formation of skin tissue abnormalities in the disease.

Adult↗
PubMed2004

Diversity of vacA and cagA genes of Helicobacter pylori in Japanese children.

BACKGROUND: Helicobacter pylori infection is generally acquired in childhood and persists as an asymptomatic infection for decades in most infected individuals. Only a minority develops a clinical outcome even in childhood, such as peptic ulcer. It has been reported that H. pylori infection with the type I strain, which expresses the VacA and CagA antigen, is associated with peptic ulcer. AIM: We examined the diversity of vacA and cagA genes in isolates obtained from Japanese paediatric patients with peptic ulcer or chronic gastritis to investigate the relationship between genetic diversity and clinical outcome. METHODS: The diversity of vacA and cagA genes was investigated by PCR and sequence analysis in 30 isolates obtained from Japanese paediatric patients with peptic ulcer (eight strains) or chronic gastritis (22 strains). RESULTS: All isolates from Japanese children were cagA-positive strains. Twenty-six strains (86.7%) had East Asian type CagA, and 4 (13.3%) had Western type CagA. The predominant vacA genotype was s1c/m1b (22/30, 73.3%). There was no significant association between the diversity of cagA and vacA genes and clinical outcome. All four children infected with Western CagA strain had a history of overseas travel or residence. CONCLUSION: The predominant genotype of H. pylori in Japanese children is East Asian CagA and vacA s1c/m1b genotype, regardless of clinical outcome. Japanese H. pylori strains are homogeneously of the East Asian type; however, Western strains can be introduced into Japan concomitant with host movement from foreign countries in childhood.

Antigens, Bacterial↗
PubMed2004

Elevated amount of human papillomavirus 31 DNA in a squamous cell carcinoma developed from bowenoid papulosis.

A 50-year-old woman presented with asymptomatic, multiple black macules on the genitalia for 6 months. She presented multiple, round to irregularly shaped, black macules on her labia major and perineum. A keratotic reddish nodule was found on one of the macules. The results of laboratory investigations showed pancytopenia and a decreased CD4/CD8 ratio. A lymphocyte stimulation test showed a decreased response. The histological examination of a biopsy specimen led us to the diagnosis of bowenoid papulosis (BP) for the macules and squamous cell carcinoma (SCC) for the nodule. The macules and nodule were removed successfully. An elevated amount of HPV DNA was demonstrated in SCC compared with that of BP. The HPV DNA in SCC and BP was shown to be HPV-31. These observations indicated that the elevated amount of HPV-31 DNA could have led to the emergence of SCC from BP under the condition of decreased cellular immunity.

Base Sequence↗
PubMed2004

Quantification of amoA gene abundance and their amoA mRNA levels in activated sludge by real-time PCR.

The transcription level of amoA mRNA encoding a subunit of ammonia monooxygenase (AMO) in ammonia-oxidizing bacteria (AOB) was quantified by reverse transcription-polymerase chain reaction (RT-PCR) methods in combination with real-time PCR technology. The effects of ammonia concentration and dissolved oxygen (DO) on the transcription levels of amoA mRNA and 16S rRNA in AOB were evaluated in batch experiments with nitrifying sludge taken from a lab-scale reactor treating artificial wastewater. A batch incubation without ammonia resulted in a rapid decrease, within four hours, in the transcription level of amoA mRNA to as low as 1/10 of that at the beginning of the experiment, while the 16S rRNA level in AOB was almost constant. After subsequent incubation with 3 mM ammonia for eight hours, a small increase in the transcription level of amoA mRNA occurred, but ammonia oxidation proceeded in the interim. Copy numbers of amoA mRNA showed an almost fixed value for over eight hours in the absence of dissolved oxygen.

Ammonia↗
PubMed2003

Effect of a novel 5-HT3 receptor agonist MKC-733 on upper gastrointestinal motility in humans.

BACKGROUND: Although 5-HT3 antagonists have been used to treat chemotherapy-induced emesis and diarrhoea-predominant irritable bowel syndrome, the effects of 5-HT3 agonists in humans are unknown. AIM: To determine the effect of MKC-733, a selective 5-HT3 receptor agonist, on upper gastrointestinal motility. METHODS: Oral MKC-733 (0.2, 1 and 4 mg) was compared with placebo in three randomized, double-blind, cross-over studies in healthy males. Antroduodenal manometry was recorded for 8 h during fasting and 3 h post-prandially (n = 12). Gastric emptying and small intestinal transit were determined by gamma-scintigraphy (n = 16). Gastric emptying, accommodation and antral motility were determined by echoplanar magnetic resonance imaging (n = 12). RESULTS: MKC-733 (4 mg) increased the number of migrating motor complexes recorded in the antrum and duodenum (P < 0.001), but had no effect on post-prandial motility. MKC-733 delayed scintigraphically assessed liquid gastric emptying (P = 0.005) and accelerated small intestinal transit (P = 0.038). Echoplanar magnetic resonance imaging confirmed the delayed gastric emptying (P < 0.001) and demonstrated a significant increase in cross-sectional area of the proximal stomach (P < 0.01). CONCLUSIONS: MKC-733 delays liquid gastric emptying in association with relaxation of the proximal stomach, stimulates fasting antroduodenal migrating motor complex activity and accelerates small intestinal transit.

Adolescent↗
PubMed2003

Modulation of interleukin-8 and nitric oxide synthase mRNA levels by interferon-gamma in macrophages stimulated with lignin derivatives and lipopolysaccharides.

It has been shown that interferon-gamma (IFN-gamma) plays a role in the regulation of interleukin-8 (IL-8), nitric oxide (NO), and tumor necrosis factor-alpha (TNF-alpha) secretion by macrophages stimulated with lignin derivatives, such as EP3, and lipopolysaccharides (LPS) [Cytokine 11 (1999) 571]. To examine the mechanism by which IFN-gamma affects secretion of these factors, EP3- or LPS-stimulated macrophages were treated with different concentrations of IFN-gamma, and mRNA levels of IL-8, nitric oxide synthase (NOS) and TNF-alpha were determined by Northern blot analysis and reverse transcription-polymerase chain reaction (RT-PCR). As reported previously, stimulation of macrophages by EP3 or LPS dramatically induced the expression of IL-8, NOS, and TNF-alpha mRNAs. IFN-gamma clearly decreased the level of IL-8 mRNA in stimulated macrophages, although it did not affect the IL-8 mRNA level in unstimulated macrophages. In contrast, IFN-gamma appeared to increase the level of NOS mRNA both in unstimulated and stimulated macrophages. IFN-gamma, which increased the amount of TNF-alpha mRNA in unstimulated macrophages, showed no significant effect on the high level of TNF-alpha mRNA in stimulated macrophages. These results suggest that IFN-gamma causes changes in IL-8 and NO secretion by stimulated macrophages through its effects on the level of IL-8 and NO mRNA, respectively. Effects of IFN-gamma on TNF-alpha secretion by stimulated macrophages may be mediated by a different mechanism.

Animals↗