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Biomedical subjects

Koichiro Tatsumi

Publications and source records attributed to Koichiro Tatsumi.

At least 19 recordsLinked to original sources
PubMed2005

Effects of obstructive sleep apnea syndrome on hepatic steatosis and nonalcoholic steatohepatitis.

Hepatic steatosis occasionally progresses to nonalcoholic steatohepatitis. This study was designed to examine whether non-obese patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) were prone to develop hepatic steatosis and whether repeated hypoxemia contributed to the progression of steatohepatitis. This study included 83 OSAHS patients and 41 age-, body mass index (BMI)- and gender-matched non-OSAHS patients diagnosed by polysomnography. Hepatic steatosis was defined by a liver/spleen ratio <0.9 on abdominal computerized tomography, and latent steatohepatitis was evaluated based on serum levels of type III procollagen (P-III-P). Visceral fat (V-fat) accumulated much more in OSAHS patients. Liver/spleen ratios in OSAHS patients correlated negatively with BMI and, especially, with the amount of visceral fat. Serum levels of P-III-P in OSAHS patients correlated negatively with the average of oxygen saturation during sleep, and positively with BMI, the apnea-hypopnea index (AHI) and the amount of V-fat. Multiple regression analysis showed that average SaO(2) was the only explanatory variable for P-III-P values, but AHI, BMI and V-fat was not. These observations confirmed that non-obese patients with OSAHS are at a risk for visceral obesity, and suggested that oxygen desaturation during sleep is a risk for developing latent steatohepatitis, especially in patients with substantial hepatic steatosis.

Journal Article↗
PubMed2005

Lymphangioleiomyomatosis with a giant bulla: report of a case.

We report a case of lymphangioleiomyomatosis (LAM) with a giant bulla. A 33-year-old woman was referred to our department for treatment of dyspnea. Chest computed tomography showed a giant bulla with many smaller bullae. To obtain a definitive diagnosis and relieve the dyspnea, we performed a lung biopsy and bullectomy, after which her symptoms and pulmonary function improved remarkably. She was commenced on progesterone, which improved her condition even further. This case report retrospectively follows the progression of her disease from the onset of symptoms 5 years before she was referred to us for treatment.

Adult↗
PubMed2005

Metabolic activity in skeletal muscles of patients with non-hypoxaemic chronic obstructive pulmonary disease studied by 31P-magnetic resonance spectroscopy.

OBJECTIVE: An alteration of high energy phosphate metabolism in muscles may contribute to exercise intolerance. The objective of this study was to clarify the changes in high energy phosphate metabolites in muscles during exercise in patients with non-hypoxaemic chronic obstructive pulmonary disease (COPD), which influences the impairment of muscle metabolism. METHODOLOGY: Calf muscle energy metabolism was studied in eight stable non-hypoxaemic COPD patients and eight control subjects, using 31P-magnetic resonance spectroscopy (MRS). MRS spectra were acquired at rest, during exercise at two levels of intensity, and during recovery. The control subjects exercised under both normoxic and hypoxic conditions. The intensity of exercise was standardized by the maximal isometric voluntary contraction (MVC) of the calf muscle and the cross-sectional area (CSA) of calf muscle. RESULTS: MVC and CSA were lower in COPD patients. No significant differences in intracellular pH, inorganic phosphate/phosphocreatine ratio or percentage recovery in inorganic phosphate/phosphocreatine ratio were observed between the two groups in muscles at rest, during exercise or during recovery. CONCLUSIONS: Muscle metabolites, during exercise standardized by muscle CSA and MVC, did not differ between non-hypoxaemic COPD patients and control subjects. MVC, CSA or both, are assumed to be closely related to muscle metabolism, as no difference in high energy phosphate metabolites was observed for COPD patients compared to control subjects when the load was standardized for MVC and CSA. This suggests that high energy metabolites are consumed to a similar extent in the same muscle volume in non-hypoxaemic COPD patients and control subjects.

Aged↗
PubMed2005

Fat accumulation, leptin, and hypercapnia in obstructive sleep apnea-hypopnea syndrome.

BACKGROUND: Obesity and visceral fat accumulation (VFA) are risk factors for the development of obstructive sleep apnea-hypopnea syndrome (OSAHS), and a subgroup of OSAHS patients acquire hypoventilation. Circulating leptin, an adipocyte-derived signaling factor, increases in accordance with body mass index (BMI); under experimental conditions, leptin selectively decreases visceral adiposity and it is also a respiratory stimulant. OBJECTIVE: To investigate whether the location of body fat deposits, ie, the distribution of VFA and subcutaneous fat accumulation (SFA), contributes to hypoventilation and whether circulating levels of leptin are involved in the pathogenesis of hypoventilation, which is often observed in OSAHS. METHODS: We assessed VFA and SFA by abdominal CT scan, and measured lung function and circulating levels of leptin in 106 eucapnic and 79 hypercapnic male patients with OSAHS. RESULTS: In the whole study group, circulating leptin levels correlated with BMI (r = 0.56), VFA (r = 0.24), and SFA (r = 0.47), but not with Po(2) or sleep mean arterial oxygen saturation (Sao(2)). BMI, percentage of predicted vital capacity, FEV(1)/FVC ratio, apnea-hypopnea index, sleep mean Sao(2), VFA, and SFA were not significantly different between two groups. Circulating leptin levels were higher in the hypercapnic group than in the eucapnic group. Logistic regression analysis indicated that serum leptin was the only predictor for the presence of hypercapnia (beta = 0.21, p < 0.01). CONCLUSIONS: These results suggest that the location of body fat deposits may not contribute to the pathogenesis of hypoventilation, and circulating leptin may fail to maintain alveolar ventilation in hypercapnic patients with OSAHS.

Adipose Tissue↗
PubMed2005

Sleep oxygen desaturation and circulating leptin in obstructive sleep apnea-hypopnea syndrome.

BACKGROUND: Obstructive sleep apnea-hypopnea syndrome (OSAHS) is characterized by repeated oxygen desaturation. Obesity and visceral fat accumulation (VFA) are risk factors for the development of OSAHS. Circulating leptin increases in accordance with body mass index (BMI), and under experimental conditions intermittent hypoxia stimulates leptin production. METHODS: The primary objective of this study was to investigate whether hypoxemia during sleep influences the levels of circulating leptin and whether the location of body fat deposits, ie, the distribution of VFA and subcutaneous fat accumulation (SFA), affects circulating leptin levels in patients with OSAHA who are not obese. We assessed VFA and SFA by abdominal CT scan and measured circulating levels of leptin in 96 male patients with OSAHS and 52 male patients without OSAHS matched for BMI. To be matched for BMI in the two groups, patients whose BMIs were < 27 were selected for the OSAHS group. RESULTS: In the whole study group, circulating leptin levels correlated with BMI (r = 0.30), VFA (r = 0.44), SFA (r = 0.28), apnea-hypopnea index (AHI) [r = 0.48], sleep mean arterial oxygen saturation (Sao(2)) [r = 0.59], and sleep lowest Sao(2) (r = 0.37). Multiple regression analysis showed that average Sao(2) (p < 0.01) and lowest Sao(2) (p = 0.03) were explanatory variables for serum leptin values, but AHI (p = 0.054), BMI (p = 0.33), VFA (p = 0.11), and SFA (p = 0.36) were not. CONCLUSIONS: These results suggest that sleep hypoxemia may be the main determinant of circulating leptin levels, although the location of body fat deposits could contribute to the elevated circulating leptin levels in patients with OSAHS who are not obese.

Abdomen↗
PubMed2005

Growth factor-mediated interaction between tumor cells and stromal fibroblasts in an experimental model of human small-cell lung cancer.

Malignant tumors induce development of their own stromal tissues during the processes of growth, progression and metastasis. Since the vascular architecture among the various stromal elements is well known to facilitate tumor growth and has been a target of therapy, the importance of stromal fibroblasts has recently been established. To elucidate the interaction between the tumor and its stromal fibroblasts, the present study took advantage of a unique experimental model consisting of a human small-cell lung cancer cell line, WA-ht, and its mouse stromal fibroblast cell line, WA-mFib, both originally derived from a xenograft tumor in a mouse subcutis. Co-culture with the WA-mFib cells significantly augmented the plating efficiency of WA-hT cells in vitro, and their co-inoculation in nude mice shortened latency and tumor doubling time. Histochemical detection of beta-gal, transfected into WA-mFib cells, demonstrated their contribution to the nude mouse xenograft tumor formation as its tumor stroma. Elevated hepatocyte growth factor (HGF) from fibroblasts followed by elevated production of vascular endothelial growth factor (VEGF) from both tumor cells and fibroblasts were demonstrated by ELISA in supernatants of their co-culture, accompanied by enhanced colonogenicity of the tumor cells; these enhanced features were not observed in their respective monocultures. Antisense oligonucleotides to HGF cancelled these augmentation effects with co-culture. The findings highlight the substantial roles of tumor stromal fibroblasts, interacting with soluble growth factors, in promoting the malignant propensity of the tumor.

Animals↗
PubMed2004

BCL-6 mutations in pulmonary lymphoproliferative disorders: demonstration of an aberrant immunological reaction in HIV-related lymphoid interstitial pneumonia.

We used a PCR and sequence procedure to analyze the Ig V(H) gene and the mutations in the 5' regulatory regions of BCL-6 genes in pulmonary lymphoproliferative disorders (mucosa-associated lymphoid tissue (MALT) lymphoma, HIV-related, EBV-related, and virus-negative lymphocytic interstitial pneumonia (LIP)). Eight of 20 (40%) pulmonary MALT lymphoma and 10 of 20 LIP (5 of 5 (100%) HIV-related, 2 of 5 (40%) EBV-related, and 3 of 10 (30%) virus-negative LIP) cases showed BCL-6 gene mutations. Intraclonal heterogeneity of the BCL-6 mutations was observed only in pulmonary MALT lymphoma cases whose Ig V(H) genes also showed intraclonal heterogeneity. Ongoing BCL-6 mutations might reflect re-entry into a germinal center pathway to further mutations. BCL-6 mutations in pulmonary MALT lymphoma and HIV-negative LIP showed some features (high transition to transversion ratio, standard polarity, and RGYW/WRCY bias) of Ig V(H) gene hypermutation, leading to the view that pulmonary MALT lymphomas and HIV-negative LIP are under the influence of germinal center hypermutation mechanisms. Because BCL-6 mutations in HIV-related LIP cases did not demonstrate features of Ig V(H) gene hypermutation, immunological reactions in HIV-related LIP are the result of a process different from that found in HIV-negative pulmonary lymphoproliferative disorders.

Adult↗
PubMed2004

Indigenous pulmonary Propionibacterium acnes primes the host in the development of sarcoid-like pulmonary granulomatosis in mice.

Although many cases of sarcoidosis are self-limiting with spontaneous remission, uncontrolled pulmonary granulomatosis with fibrosis produces intolerable long-term respiratory symptoms in a minority of patients. Individuals with chronic pulmonary sarcoidosis require an alternative therapy to corticosteroidal treatment because of its insufficient effectiveness. Although many researchers have considered infection as the triggering factor for this disease, the mechanisms by which the candidate causative organisms induce this disorder remain unclear. We report here that extrapulmonary sensitization to Propionibacterium acnes, which is one of the candidates to date, induced pulmonary Th-1 granulomas mainly in the subpleural and peribronchovascular regions often observed in sarcoidosis. These granulomas appear to be caused by indigenous P. acnes pre-existing in the lower respiratory tract of the normal lung, which is believed to be germ-free, and by an influx of P. acnes-sensitized CD4(+) T cells from the circulation. Importantly, the eradication of indigenous P. acnes with antibiotics alleviated the granulomatous lung disease. This is the first report to present clear evidence of the contribution of an indigenous pulmonary bacterium to the formation of granulomatous lesions in the lung. We propose that treatment targeting indigenous P. acnes in the lung may be a possible remedy for pulmonary sarcoidosis.

Animals↗
PubMed2004

In vitro conversion of irinotecan to SN-38 in human plasma.

Irinotecan is an active cytotoxic agent for various cancers, and is converted to SN-38, its most active metabolite, by carboxylesterase converting enzyme (CCE) in vivo. Although the primary metabolic site is in the liver, ex vivo studies have proven that irinotecan is also converted to SN-38 in intestines, plasma and tumor tissues. The present study attempted to elucidate the in vitro conversion efficiency in human plasma, and to examine possible inter-individual variability and its clinical significance. Plasma samples were taken from 57 patients with lung cancer, 3 patients with benign pulmonary diseases and 9 healthy volunteers. After addition of 157 mM irinotecan to plasma, time courses of SN-38 concentration, measured by high-performance liquid chromatography (HPLC), were investigated. All subjects showed linear increase in SN-38 concentration during the first 60-min period, followed by a plateau. Mean and standard deviation of the conversion rate in the first 60 min were 515.9 +/- 50.1 pmol/ml/h (n = 69), with a coefficient of variation of 0.097. Although most of the subjects showed comparable conversion rates, 3 subjects had significantly higher conversion rates. In conclusion, the results of this study suggest that the enzyme activity of CCE in human plasma may show inter-individual variability.

Adult↗
PubMed2004

Polymorphism of the promoter region of prostacyclin synthase gene in chronic thromboembolic pulmonary hypertension.

OBJECTIVE: Decreased expression of prostacyclin synthase (PGIS) is observed in the lung vasculature of patients with pulmonary arterial hypertension and the biosynthesis of prostacyclin (PGI2) may be impaired in chronic thromboembolic pulmonary hypertension (CTEPH). Whether it is genetically determined or develops as the disease progresses is unclear. A variable-number tandem repeat (VNTR) polymorphism has been detected in the 5'-upstream promoter region of the PGIS gene. It has been demonstrated that the alleles vary in size from three to seven repeats of nine base pairs, and transcriptional activity increased with the number of repeats. The purpose of the present study was to elucidate the association between the VNTR polymorphisms of the PGIS gene and CTEPH in Japanese subjects. METHODOLOGY: Ninety patients with CTEPH and 144 control subjects were investigated for the presence of VNTR polymorphisms. Sixty-two blood samples were obtained from CTEPH patients and the plasma concentrations of prostacyclin and thromboxane A2 metabolites were measured. RESULTS: VNTR polymorphisms in the prostacyclin synthase gene were grouped into L alleles (five, six and seven repeats) and S alleles (three and four repeats). The overall distribution of the alleles and genotypes were not significantly different between CTEPH patients and the control subjects. The patients with the LL genotype had higher plasma concentrations of 6-keto-prostaglandin F1alpha than patients with the LS and SS genotypes. CONCLUSIONS: Our results suggested that the specific VNTR polymorphism in the 5'-upstream promoter region of the PGIS gene regulated prostacyclin production, but did not seem to be associated with the development of CTEPH in this patient population.

Chronic Disease↗
PubMed2004

Clinical phenotypes of COPD: results of a Japanese epidemiological survey.

OBJECTIVE: The Global Initiative for Obstructive Lung Disease characterizes COPD as airflow limitation caused by parenchymal destruction and/or small airway disease. This report characterizes the clinical features of these two phenotypes of COPD in Japan. METHODOLOGY: COPD was diagnosed by spirometric airflow limitation (FEV(1)/FVC < 70%), and all subjects underwent chest CT scanning. Patients with diffuse low attenuation areas (LAA) on CT scan were categorized as the emphysema-dominant phenotype; those with little LAA were categorized as the airway disease-dominant phenotype. The two groups were compared to identify significant clinical or demographic differences. RESULTS: Of the 1438 patients analysed, 1294 (90%) were classified as having an emphysema-dominant phenotype and 144 (10%) as having an airway disease-dominant phenotype. The airway disease-dominant phenotype was: more common than the emphysema-dominant phenotype in women (15%vs. 7%, P < 0.01) and in non-smokers (6%vs. 2%, P < 0.05); was more commonly complicated by asthmatic features (35%vs. 21%, P < 0.01); and had higher IgE and eosinophil levels (P < 0.05) and less lung function impairment. CONCLUSION: This analysis is the first to clinically define two phenotypes of COPD in a Japanese epidemiological survey. There appear to be striking differences as well as overlap between these two groups. Further research is warranted to determine the significance of COPD phenotypes.

Female↗
PubMed2004

[A case of bronchostenosis in the allograft after lung transplantation in pulmonary lymphangioleiomyomatosis].

Pulmonary lymphangioleiomyomatosis (LAM) is a rare disease characterized by hamartomatous proliferation of abnormal smooth muscle cells in the lungs. Recently, severe LAM has been listed as an indicated disease for lung transplantation. A 34-yr-old woman with severe pulmonary cystic changes in a chest CT scan was diagnosed as having an isolated form of pulmonary LAM without genetic disorders. Despite intensive progesterone treatment, her pulmonary functions deteriorated rapidly. In January 2001, a left single-lung transplantation was performed from a cadaveric donor. The total operating time was 8 hours and 47 minutes. Total ischemic time was 5 hours and 59 minutes, which was within the permitted time limit. Except for right pneumothorax, the postoperative course was fairly good without any sign of rejection or infection in the allograft. For about two months after transplantation, bronchostenosis occurred in the left lower lobe bronchus, and necessitated a stent placement. During the following three months, stenosis of the bronchi in the anastomotic and peripheral sites occurred repeatedly, which also necessitated stent placement or balloon dilations on each occasion. Despite all the intensive treatment, the bronchostenosis of the peripheral sites still remains and improvement of her pulmonary functions has been poor. Moreover, a recent chest CT scan revealed a progression of the disease in the native lung. Consequently, we registered her as a candidate for transplantation of the right lung. Bronchostenosis should be kept in mind as a complication of lung transplantation.

Adult↗
PubMed2004

Effect of aeration on gliotoxin production by Aspergillus fumigatus in its culture filtrate.

Gliotoxin, one of the mycotoxins produced by Aspergillus fumigatus, has various, potent bioactivities. However, it has not been considered to be a toxic (or virulence) factor because of its slow production. The aim of the present study was to investigate the effects of aeration on the cytotoxicity of A. fumigatus culture filtrate, and to determine the optimal condition for the rapid production of gliotoxin from this fungus. Fungal culture filtrates were made in three different containers under various conditions of aeration and O2 concentration. These filtrates were compared in terms of their cytotoxicity on murine macrophages and analyzed by gas chromatography. The culture filtrate showed high cytotoxicity when it was made under highly aerated conditions, but it was significantly less cytotoxic when prepared under non-aerated conditions. The cytotoxic activity became evident within 15 h of culture at 20% O2, when the fungus had already started producing gliotoxin. The culture filtrates also contained some other as yet unidentified substances that might also to some extent contribute to the cytotoxicity. In light of these results, the authors propose that a highly aerated condition is responsible for the rapid production of gliotoxin, and that gliotoxin might play an important role in the respiratory infection by A. fumigatus, with other toxic substances acting additively or synergistically.

Animals↗
PubMed2004

Effect of aeration on gliotoxin production by Aspergillus fumigatus in its culture filtrate.

Gliotoxin, one of the mycotoxins produced by Aspergillus fumigatus, has various, potent bioactivities. However, it has not been considered to be a toxic (or virulence) factor because of its slow production. The aim of the present study was to investigate the effects of aeration on the cytotoxicity of A. fumigatus culture filtrate, and to determine the optimal condition for the rapid production of gliotoxin from this fungus. Fungal culture filtrates were made in three different containers under various conditions of aeration and O2 concentration. These filtrates were compared in terms of their cytotoxicity on murine macrophages and analyzed by gas chromatography. The culture filtrate showed high cytotoxicity when it was made under highly aerated conditions, but it was significantly less cytotoxic when prepared under non-aerated conditions. The cytotoxic activity became evident within 15 h of culture at 20% O2, when the fungus had already started producing gliotoxin. The culture filtrates also contained some other as yet unidentified substances that might also to some extent contribute to the cytotoxicity. In light of these results, the authors propose that a highly aerated condition is responsible for the rapid production of gliotoxin, and that gliotoxin might play an important role in the respiratory infection by A. fumigatus, with other toxic substances acting additively or synergistically.

Aerobiosis↗
PubMed2003

Detection of tumor specific gene expression in bone marrow and peripheral blood from patients with small cell lung carcinoma.

BACKGROUND: Small cell lung carcinoma (SCLC) has the propensity to grow rapidly and metastasize extensively. Detection of micro-dissemination of SCLC may have clinical relevance. For its detection, tumor-specific gene expressions were examined in peripheral blood and bone marrow aspirate from patients with SCLC. METHODS: Expression of prepro-gastrin-releasing peptide (preproGRP), neuromedin B receptor (NMB-R) and gastrin-releasing peptide receptor (GRP-R) were examined by reverse transcriptase polymerase chain reaction (RT-PCR) in peripheral blood and bone marrow aspirate from 40 untreated patients with SCLC. Control samples consisted of peripheral blood samples from 5 patients with nonsmall cell lung cancer (NSCLC) and 20 healthy volunteers. RESULTS: Positive rates of preproGRP, NMB-R, and GRP-R in bone marrow aspirate of patients with SCLC were 23% (9/40), 8% (3/40), and 10% (4/40), respectively. Those rates in peripheral blood were 11% (4/38), 5% (2/38), and 29% (11/38), respectively. Although GRP-R expression was detected in patients with NSCLC and in healthy volunteers, preproGRP and NMB-R expressions were not detected in patients with NSCLC and in healthy volunteers. All three gene expressions in bone marrow were more frequently observed in patients with bone marrow metastasis, accessed by biopsy, than in patients without. PreproGRP gene expression in bone marrow was also more frequent in patients with bone metastasis, accessed by bone scintigram, than in patients without, and was related to poorer survival. CONCLUSIONS: Micro-dissemination of SCLC was detectable by RT-PCR of preproGRP and NMB-R, both specific for SCLC. These gene expressions in bone marrow may be related to disease extent and prognosis.

Adult↗