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S Kira

Publications and source records attributed to S Kira.

At least 19 recordsLinked to original sources
PubMed2006

Effects of high peak airway pressure on the expression of heat shock protein 70 in rat lungs: a preliminary study.

BACKGROUND: Heat shock protein 70 (HSP70) is induced by a wide variety of stresses in addition to hyperthermia. Recent studies have clarified that mechanical stretching and pressure overload can induce HSP70 in some tissues and cells. However, it remains unclear whether HSP70 is induced in stretch-subjected lungs, such as those under mechanical ventilation. This study was designed to investigate the effects of high peak airway pressure (PAP) ventilation on HSP70 expression in intact rat lungs. METHODS: Male Sprague-Dawley rats were randomly allocated to one of three groups: non-ventilated (anesthesia alone) control group; PAP 15 cm H(2)O group (P15); and PAP 30 cm H(2)O group (P30). The rats in the PAP groups were subjected to pressure-controlled assisted ventilation at the appropriate PAP for 30 min. Rats were killed at 12, 24 and 48 h after ventilation or anesthesia alone, and the lungs were removed. The lung tissues were processed for immunohistochemical and Western blotting analyses of HSP70. RESULTS: Following 30 min of pressure-controlled assisted ventilation, HSP70 expression in the P30 group was significantly up-regulated in bronchiolar cells and subepithelial tissues at 12 h, and this up-regulation continued throughout the observation period. In contrast, there were no significant differences between the control and P15 groups, although the expression of HSP70 was higher in the P15 group than in the control group at all time points. CONCLUSIONS: HSP70 was induced by high PAP ventilation, but its specific role and induction mechanism remain unclear. Therefore, further investigations should be encouraged.

Airway Resistance↗
PubMed2005

Mild hypothermia reduces expression of intercellular adhesion molecule-1 (ICAM-1) and the accumulation of neutrophils after acid-induced lung injury in the rat.

BACKGROUND: The pathophysiology of the acute phase of acid-induced lung injury (AILI) has been elucidated. However, once acute respiratory distress syndrome (ARDS) develops, the mortality rate remains high and there is, as yet, no effective therapy. There are reports that application of mild hypothermia is an effective treatment for ARDS. In this study, we hypothesize that mild hypothermia inhibits activation of neutrophils and expression of intercellular adhesion molecule-1 (ICAM-1) in an injured lung. We studied the effects of mild hypothermia on the expression of ICAM-1 and the accumulation of neutrophils after AILI in the rat. METHODS: Male Sprague-Dawley rats were randomly allocated to one of the four groups: control normothermic group, induced mild hypothermia group, acid-instilled normothermic group, and acid-instilled group with mild hypothermia. At 6 h after instillation of acid, lungs were removed to measure neutrophil activity and to detect the expression of ICAM-1 in each group. RESULTS: Oxygenation in acid-instilled rats was significantly impaired as compared to that in non-instilled groups, but induction of mild hypothermia gradually improved oxygenation. Expression of ICAM-1 was enhanced in the acid-instilled normothermic group. By contrast, no overexpression of ICAM-1 and its mRNA was detected in the acid-instilled hypothermic group. In addition, accumulation of neutrophils was markedly inhibited after exposure to mild hypothermia irrespective of the instillation of acid. CONCLUSION: Our data suggest mild hypothermia can inhibit the adhesion, activation, and accumulation of neutrophils during the acute phase of AILI in the rat and may have the potential to reduce ongoing inflammation of ALI or ARDS.

Analysis of Variance↗
PubMed2004

Olprinone improves diaphragmatic contractility and fatigability during abdominal sepsis in a rat model.

BACKGROUND: Respiratory failure with diaphragmatic fatigability is common in patients suffering sepsis or septic shock. However, the development and progress of diaphragmatic fatigability remains poorly understood, and no method has been established to treat fatigability. In this study, we hypothesize that neutrophil activation contributes to the development of diaphragmatic fatigability. We also sought to investigate whether a phosphodiesterase inhibitor, olprinone, improves diaphragmatic fatigability associated with abdominal sepsis and inhibits an increase in myeloperoxidase activity in diaphragmatic muscle. METHODS: Male Wistar rats were randomly assigned to a sham group, coecal legation perforation group (CLP), and a phosphodiesterase inhibitor (PDE) pretreated group. At 16 h after surgical procedure, the left hemidiaphragm was removed for the measurement of diaphragmatic contractility and fatigability. In addition, for the measurement of serial changes in myeloperoxidase activity, the right hemidiaphragm was also removed at 4, 8 or 16 h after the surgical procedure in each group. RESULTS: In a septic model involving rats, we observed that diaphragmatic muscles were fatigable and myeloperoxidase activity increased. We also demonstrated that intraperitoneal administration of olprinone improves diaphragmatic fatigability and inhibits an increase in myeloperoxidase activity induced by abdominal sepsis. CONCLUSION: Olprinone represents a potential therapy for cases of respiratory failure with diaphragmatic fatigability resulting from inhibition of neutrophil activation.

Abdomen↗
PubMed2004

Effects of acute moderate exercise on the phagocytosis of Kupffer cells in rats.

AIM: This study investigated the function of Kupffer cells, and particularly their role as immunocompetent cells that come into contact with gut-derived endotoxin, in the acute exercise of rats. METHODS: Female Fischer 344 rats were run on a treadmill at 21 m min(-1) for 60 min on a 15% grade. RESULTS: Afterwards, the number of latex particles in the liver was higher in the exercising rats than that in resting rats and an increase in the number of latex particles phagocytosed by each Kupffer cell was noted. The plasma endotoxin concentration was significantly higher in the exercise group than in the resting rats, and the small intestine was damaged by the exercise. Plasma corticosterone and thyroxine 4 levels were unchanged. Although the number of Kupffer cells was unchanged by acute exercise, the number of CD14-positive Kupffer cells increased. Plasma liver enzyme activities were slightly increased by acute exercise, whereas plasma tumour necrosis factor-alpha was not detected. CONCLUSION: These results suggest that moderately intense exercise increases the phagocytosis of Kupffer cells, and that it might be induced by endotoxemia of portal blood caused by intestinal mucosal lesions resulting from acute exercise.

Animals↗
PubMed2004

Changes in serum leptin concentrations in overweight Japanese men after exercise.

AIM: To investigate the link between serum leptin concentrations and exercise. DESIGN: Cross-sectional and longitudinal studies of an exercise intervention. SUBJECTS: 110 Japanese overweight men aged 32-59 years were recruited. At baseline, the average body mass index (BMI) was 28.5 +/- 2.5 kg/m2. From this group, we used data of 36 overweight men (BMI, 28.9 +/- 2.3) for a 1-year exercise programme. MEASUREMENTS: Leptin was measured at baseline and after 1 year. Fat distribution was evaluated by visceral fat (V) and subcutaneous fat (S) areas measured with computed tomography (CT) scanning at umbilical levels. Anthropometric parameters, aerobic exercise level, muscle strength and flexibility were also investigated at baseline and after 1 year. RESULTS: In the first analysis, using cross-sectional data, leptin was significantly correlated with total body fat (r = 0.760, p < 0.01), V (r = 0.383, p < 0.01) and S (r = 0.617, p < 0.01) areas. In the second analysis, using longitudinal data, leptin was significantly reduced after 1 year (pre 6.7 +/- 4.0 ng/ml vs. post 5.1 +/- 3.1 ng/ml, p < 0.01). Results showed that steps per day were increased, and aerobic exercise level, weight-bearing index (WBI) and insulin resistance were significantly improved. Although, there was a positive correlation between Delta leptin(positive changes in leptin after 1 year) and anthropometric measurements such as Delta body weight, Delta BMI and Delta body fat, leptin/body weight, leptin/BMI and leptin/body fat ratios were significantly reduced during exercise intervention. CONCLUSION: The present study indicated exercise significantly lowers serum leptin concentrations, and thus it may improve the leptin resistance observed in overweight Japanese men.

Adult↗
PubMed2003

Serum bFGF levels are reduced in Japanese overweight men and restored by a 6-month exercise education.

OBJECTIVE: To investigate whether the changes in vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) concentrations before and after weight reduction in Japanese overweight men are associated with changes in body mass index (BMI), visceral, subcutaneous fat, VO(2) and work rate (WR) at ventilatory threshold (VT). DESIGN: Cross-sectional and longitudinal clinical intervention study with exercise education. SUBJECTS: In total, 30 Japanese overweight men (BMI, 29.0+/-2.2 kg/m(2)) and 31 normal-weight men (BMI, 22.5+/-1.6 kg/m(2)) at baseline were enrolled: 30 overweight men (BMI, 29.0+/-2.2 kg/m(2)) were further enrolled into a 6-month exercise program. MEASUREMENTS: Fat distribution evaluated by visceral fat (V) and subcutaneous fat (S) areas measured with computed tomography scanning at umbilical levels, angiogenic peptides including VEGF and bFGF, exercise tests at baseline and after 6 months. RESULTS: In normal-weight and overweight subjects at baseline, VEGF positively correlated with S area (r=0.350, P=0.007) but not with V area. In contrast, bFGF negatively correlated with BMI (r=-0.619, P<0.001), S (r=-0.457, P<0.001) and V areas (r=-0.466, P<0.001). By intervention with exercise education, 30 overweight subjects showed reduction in BMI (29.0+/-2.2 to 28.0+/-2.0, P<0.001), V and S areas, increase in VO(2) and WR at VT, increase in bFGF (9.21+/-5.82-21.2+/-7.04 ng/ml, P<0.001), and no change in VEGF (1.45+/-0.72-1.88+/-0.52 ng/ml, P=0.016). The stepwise multiple regression analysis revealed that DeltaBMI (beta=-6.052) and DeltaVO(2) (beta=2.806) were independently related to DeltabFGF (P<0.001) and all other variables including DeltaS area, and DeltaV area, and DeltaWR did not enter the equation at significant levels. CONCLUSION: The present study indicated a negative correlation between serum bFGF levels and BMI at baseline as well as an association of DeltaBMI and DeltaVO(2) with DeltabFGF after exercise intervention. The exercise-induced elevation of bFGF may be beneficial in the prevention of the atherosclerosis in overweight subjects.

Adipose Tissue↗
PubMed2002

Relationship between reduced serum IGF-I levels and accumulation of visceral fat in Japanese men.

OBJECTIVE: To investigate whether the changes in IGF-I concentrations after weight reduction in Japanese overweight men are associated with changes in visceral and subcutaneous fat. DESIGN: Cross-sectional and longitudinal clinical intervention study with exercise education. SUBJECTS: One-hundred and twelve Japanese overweight men aged 30-59 y (body mass index (BMI) 28.4+/-2.5 kg/m(2)) and 33 normal-weight men aged 30-39 y (BMI 22.1+/-1.5 kg/m(2)) at baseline. From the participants, 56 randomly selected overweight men (BMI 28.8+/-2.8) were further enrolled into a 1 y exercise program. MEASUREMENTS: Fat distribution was evaluated by visceral fat (V) and subcutaneous fat (S) areas measured with computed tomography scanning at umbilical levels, metabolic parameters and hormones including insulin, leptin and IGF-I at baseline and after 1 y. RESULTS: In 112 overweight subjects at baseline, insulin (10.5+/-5.0 microU/ml) and leptin (6.4+/-3.7 ng/ml) significantly correlated with both V (r=0.260, P=0.0073; r=0.410, P<0.0001) and S areas (r=0.377, P<0.0001; r=0.613, P<0.0001), respectively. IGF-I (156.8+/-48.7 microU/ml) significantly and negatively correlated with V area (r=-0.242, P=0.0125) and age (r=-0.192, P=0.0480). In normal-weight men aged 30-39 y (n=33) and age-matched subjects (n=30) selected from the 112 overweight men, the serum IGF-I further tightly correlated with V area (r=-0.467, P<0.0001). Visceral fat area and age were independently related to serum IGF-I levels by multiple regression analysis. By intervention with exercise education, 56 overweight subjects showed an increase in daily steps (6224+/-2781 to 7898+/-4141 steps/day) and reduction of BMI (28.8+/-2.8 to 27.7+/-2.9). deltaIGF-I significantly correlated with deltaV area (r=-0.432, P=0.0009) but not with DeltaS area or deltaBMI. CONCLUSION: The present study indicated a negative correlation between IGF-I levels and visceral fat at baseline as well as an association between the reduction in visceral fat and increase in IGF-I levels after an exercise intervention.

Adipose Tissue↗
PubMed2001

cDNA cloning and expression of mutant catalase from the hypocatalasemic mouse: comparison with the acatalasemic mutant.

Mutant catalase cDNAs from the hypocatalasemic and acatalasemic mice were cloned and expressed in bacteria. A novel missense mutation, Asp (AAT) to Ser (AGT), was identified at amino acid position 439 of the hypocatalasemic catalase. Analysis of recombinant catalase mutants revealed that the mutation is responsible for the reduced activity of hypocatalasemic catalase and the unstable tetrameric structure of acatalasemic catalase was also suggested.

Acatalasia↗
PubMed2001

Lead content of brain tissue in diffuse neurofibrillary tangles with calcification (DNTC): the possibility of lead neurotoxicity.

Diffuse neurofibrillary tangles with calcification (DNTC) is a form of presenile dementia, characterized pathologically by fronto-temporal atrophy with neurofibrillary tangles (NFTs), neuropil threads and Fahr-type calcification, in which no senile plaques are observed. As already noted, chronic exposure to lead (Pb) might be one of the etiological factors of Fahr-type calcification. Until now, there have been no reports in which Pb concentration has been quantified in DNTC brains. We examined the concentration of Pb in fresh-frozen brain tissue and in 10% formalin-fixed brain tissue from six cases of DNTC, four cases of Alzheimer's disease, and in nine non-demented elderly controls by flameless atomic absorption spectrometry, and demonstrated a high concentration of Pb in DNTC brains. Although it remains unclear how these findings are related to the formation of NFTs, they suggest that Pb neurotoxicity may be involved in the pathogenesis of DNTC.

Aged↗
PubMed2001

Longitudinal follow-up study of 11 patients with pulmonary lymphangioleiomyomatosis: diverse clinical courses of LAM allow some patients to be treated without anti-hormone therapy.

OBJECTIVE: The purpose of this study is to clarify the existing issues on the clinical diversity, natural history, and mode of disease progression of pulmonary lymphangioleiomyomatosis (LAM). METHODOLOGY: Eleven patients with LAM were reviewed retrospectively with special reference to serial changes in pulmonary function and radiological findings during the course of their disease, treatment, and outcome. All patients were female with a mean age of 33.8 years at presentation and the observation period ranged from 2.1 to 20.8 years (mean 7.4 years). RESULTS: Four of six patients, treated with anti-hormone therapy, presented with exertional dyspnoea, marked airflow limitation (forced expiratory volume in 1 s/forced vital capacity, 23-38%), and severely impaired diffusing capacity (%DLCO, 21.4-36% of the predicted). The remaining two patients showed only a decreased diffusing capacity (70.6% and 59.4% of the predicted) which rapidly deteriorated with subsequent development of airflow limitation. Repeated chest computed tomographic (CT) examinations revealed increasing numbers of cysts with simultaneous loss of normal lung parenchyma in these two patients. In contrast, the five patients who received no anti-hormone therapy had no respiratory symptoms aside from pneumothorax at onset. Remarkable differences were noted, with pulmonary function being well maintained and slow progression of cystic changes on CT being observed in the latter group. CONCLUSIONS: Diverse clinical courses observed in patients with pulmonary LAM can be well delineated and assessed by periodic examinations including pulmonary function tests and chest CT imaging. Anti-hormone therapy is not always necessary for a certain group of LAM patients and they appear to have a stable course and favourable outcomes without anti-hormone treatment.

Adult↗
PubMed2001

[Evaluation of spontaneous pneumothorax in patients with pulmonary lymphangioleiomyomatosis].

We retrospectively evaluated the development of spontaneous pneumothorax in patients with pulmonary lymphangioleiomyomatosis (LAM). Fifteen patients with LAM, whose diagnosis was confirmed histopathologically, were enrolled. All were women, and had a mean age at diagnosis of 31.6 +/- 7.3 years. They were divided into two groups according to the presence or absence of pneumothorax at the time of onset, Group A consisting of nine patients with pneumothorax, and Group B, of six without pneumothorax. Spontaneous pneumothorax developed in 15 out of a total of 18 hemithoraces in Group A patients in whom 13 hemithoraces were surgically treated for pneumothorax (eight open thoracotomies and five video-assisted thoracoscopic surgeries). Bullectomy with either parietal pleurectomy, pleural abrasion, or instillation of chemical irritants to prevent the recurrence of pneumothorax offered better outcomes than bullectomy alone in terms of the postoperative recurrence rate of pneumothorax (p < 0.05). On the other hand, three of the five Group B cases developed pneumothorax during the course of LAM, but none was operated because of severely impaired lung function. The other patient in Group B was not only free of pneumothorax at onset, but also did not develop pneumothorax or suffer from impaired lung function. There were no deaths due to pneumothorax recorded among Group A patients, but two patients in group B died. A better survival rate was noted in Group A than in Group B by Kaplan-Meier analysis, suggesting that these two groups may represent the broad clinical spectrum of LAM.

Adult↗
PubMed2000

The prevalence of pleural plaques and/or pulmonary changes among construction workers in Okayama, Japan.

BACKGROUND: Since asbestos has been widely used in Japanese building materials since 1960s, a large number of Japanese construction workers may be exposed to asbestos occupationally. METHODS: Among 2951 construction workers in Okayama, Japan, the prevalence of asbestos-induced pleural or pulmonary changes was examined by screening chest x-rays; these findings were confirmed by computed tomography (CT) scanning of the chest. RESULTS: Among 2951 construction workers, 168 (5.7%) were found to have significant findings for pleural plaque or pulmonary changes on chest x-ray. Seventy-four had both pleural plaque and asbestosis, 85 pleural plaques alone, and 9 asbestosis alone. In 11 subjects, pleural plaques were suggested by chest x-ray, but neither pleural plaque nor asbestosis was demonstrated by chest CT. Honeycombing as one of the characteristic findings of asbestosis was found in 29 subjects. Others showed subpleural spots or curvilinear shadow, which suggested the early stage of asbestosis. The occupations of these workers were carpenters (64), plasterers (27), and concrete board cutters (14). About 30% of the workers with these findings were aware that they were handling asbestos in activities such as installation of asbestos boards, and/or asbestos spraying. CONCLUSIONS: As the incidence of malignant mesothelioma and primary lung cancer associated with asbestos exposure are high, screening by chest CT is necessary for detecting asbestos-induced pulmonary and/or pleural lesions. Education for protection such as telling about the presence of asbestos in building materials is also necessary.

Asbestosis↗
PubMed2000

Characterization of two types of mitochondrial creatine kinase isolated from normal human cardiac muscle and brain tissue.

Two types of mitochondrial creatine kinase (Mi-CK), sarcomeric (sMi-) and ubiquitous (uMi-)CKs, were isolated from normal human cardiac muscle and brain tissue, respectively, and their heterogeneity was characterized by means of isoelectric focusing (IEF). Octameric sMi-CK and uMi-CK were electrophoresed cathodic to cytoplasmic muscle-type creatine kinase isoenzyme (CK-MM) and dimeric Mi-CKs were found at the position of CK-MM on a cellulose acetate membrane. The electrophoretic mobilities of sMi-CK were similar to those of uMi-CK. Octameric sMi-CK was focused at pI 7.1-8.0 and dimeric forms at pI 6.55, 6.75, 6.85, and 6.95. New bands appearing at pI 6.65 and 6.75 after treatment of sMi-CK with carboxypeptidase B were found to be delysined forms. sMi-CK reacted with anti-sMi-CK antibodies, and the immune complexes were focused at pI 5.8. The Km value of sMi-CK for creatine phosphate (PCr) was 1.19 +/-0.20 mmol/L (mean +/- standard error), the activation energy (Ea) was 108.3+/-1.2 kJ/ mol, and the residual enzyme activity after heating at 45 degrees C for 20 min was 79.6+/-1.9%. On the other hand, octameric uMi-CK was focused at pI 7.1-7.9 and the dimeric forms were focused at pI 6.6, 6.7, 6.8, 6.9, and 7.0. Delysined forms were focused around pI 6.3, 6.4, 6.8, and 6.9. uMi-CK reacted with anti-sMi-CK antibodies, and the immune complexes were focused at pI 5.8. The Km value of uMi-CK for PCr was 1.07+/-0.03 mmol/L, Ea of uMi-CK was 110.0+/-0.9 kJ/mol, and the residual enzyme activity after heating at 45 degrees C for 20 min was 90.3+/-0.4%. The sMi-CK and uMi-CK were hybridized and the hybrid Mi-CK appeared at pI 6.78, 6.98, and 7.1-7.95. The pIs of the hybrid Mi-CK were between those of sMi-CK and uMi-CK. As described above, sMi-CK and uMi-CK were slightly different from each other with respect to the pI and some enzyme characteristics.

Brain↗
PubMed2000

Epidemiological studies of coincidental outbreaks of enterohemorrhagic Escherichia coli O157:H7 infection and infectious gastroenteritis in Niimi City.

A sharp rise in the number of patients with infectious gastroenteritis was observed in the 25th week of year 1996 in the Takahashi-Ashin district by researchers with the Infectious Disease Surveillance Program for tuberculosis and other infectious diseases in the Okayama Prefecture. This sharp rise occurred coincidentally with an outbreak of enterohemorrhagic Escherichia coli O157:H7 (EHEC O157) infection in Niimi City of the Takahashi-Ashin district. However, this phenomenon of coincidental outbreaks was not observed during the outbreak of EHEC O157 infection in Oku Cho. By reviewing outpatients' charts in a sentinel hospital in Niimi City for the Infectious Disease Surveillance Program, it was noted that patients with acute gastrointestinal infection visiting the hospital during the increased incidence of infectious gastroenteritis may have been included as misclassified cases of EHEC O157 infection. On the other hand, the exponential probability plotting of symptomatic patients with EHEC O157 infection in Niimi City revealed a breaking point which suggested a dual exposure to contaminated food or an overlap with other acute gastrointestinal infections. The latter possibility was discounted, because stool culture-positive patients with EHEC O157 infection also exhibited a similar breaking point, and furthermore, the coincidental increase in infectious gastroenteritis in the same area was attributable to the EHEC O157 infection. The present study demonstrates the association between the sharp rise in gastroenteritis and the outbreak of EHEC O157 in the Takahashi-Ashin district. A careful analysis of the cases of infectious gastroenteritis by the Infectious Disease Surveillance Program would have predicted the outbreak of EHEC O157.

Disease Outbreaks↗
PubMed2000

[A study of the difficulty of identifying normal intrathoracic structures on CRT images: a search for the optimal luminescence ratio].

This study was concerned with 2 issues: whether there are any normal intrathoracic anatomical structures that are relatively more difficult to identify on CRT (cathode-ray tube) monitor images, and if so, what their features are. Four physicians examined 7 intrathoracic anatomical structures on 50 chest roentgenograms that were displayed on CRT monitors and as conventional X-ray films on a light box. They categorized the visibility of each structure into 5 grades. The 7 structures were the spinal process behind the trachea, right margin of trachea, right main bronchus, left main bronchus, vascular shadow behind right diaphragm, vascular shadow behind cardiac shadow, and right margin of descending aorta. Luminescence ratios were calculated as the ratio of the density of a given viewpoint relative to adjacent areas on the images. We also examined the correlations between luminescence ratio and degree of difficulty in interpreting CRT images at a variety of selected luminescence ratios. Although the spinal process and trachea were easy to identify on CRT images as well as conventional films, other structures were difficult to recognize on CRT images. The luminescence ratio of each structure was higher on conventional film, and relatively low for those structures that were difficult to identify on CRT images. Each structure became gradually easier to identify with increasing luminescence ratios, up to a value of 1.07 maximum. However, this improvement in visibility leveled off beyond 1.07. We concluded that the luminescence ratio should be maintained at more than 1.07 to facilitate optimal identification of overlapping anatomical structures on CRT images.

Aorta, Thoracic↗