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Biomedical subjects

H Osawa

Publications and source records attributed to H Osawa.

At least 37 records · Page 2Linked to original sources
PubMed2003

[Complications of major lung resections by video-assisted thoracoscopic surgery].

Lobectomy by video-assisted thoracoscopic surgery (VATS) is gradually being performed more frequently because of advantages regarding pain and pulmonary function. Complications sometimes occur during or after VATS lobectomy. The purpose of this study was to analyze the incidence and the causes of the complications. From 1997 to 2003, 185 patients underwent VATS lobectomies. Selected diseases for this approach included primary lung cancer (n = 172), metastatic lung cancer (n = 7), benign lung tumors (n = 3) and lung sequestration (n = 3). The VATS approach was converted to open thoracotomy in 15 (8.1%) of 185 patients because of bleeding (n = 8), dense hilar adenopathy (DHA, n = 3), local extent of disease (n = 3) of intraoperative cardiac trouble (n = 1). Intraoperative complications involved injury to a blood vessel (n = 21), stapling failure (n = 15), lung injury (n = 7), nerve injury (n = 3), and others. Predictive factors for injury to pulmonary arteries was DHA (OR 37.0, p < 0.0001). Postoperative surgical death occurred in 2 patients due to pneumonia. Postoperative morbidity was 22.9%. A surgical operation without any good direct or thoracoscopic view or the use of a thoracoscopic tool without knowledge of the directions on its use should be avoided. The VATS approach should be replaced by open thoracotomy if there are DHA.

Humans↗
PubMed2002

[Clinical study of eight thymic carcinomas].

Eight patients with thymic carcinoma were surgically treated at Sapporo City General Hospital from September 1990 to January 2002. The histological subtypes of thymic carcinoma were squamous cell in 5, undifferentiated in 2, and small cell in one. After median sternotomy, 5 patients had total resection of the tumor, and 3 had incomplete resection due to extensive mediastinal invasion involving the main pulmonary artery in the A-P window. Of 3 cases with intra pericardial malignant effusion, one patient survived 7 years without recurrence of the tumor after the exploratory operation followed by mediastinal irradiation without chemotherapy. In this patient, existence of the malignant cells in the pericardial effusion was not associated with poor outcome.

Adult↗
PubMed2002

[A new formula to calculate perfusion rate in advanced hemodilution and tepid cardiopulmonary bypass].

BACKGROUND: During cardiopulmonary bypass, perfusion flow rate is generally calculated only with the patient body surface. Recently, far advanced hemodilution during cardiopulmonary bypass and tepid bypass circulation are common. PURPOSE: We have arrived at an appropriate flow rate formula, in which factors like temperature, hemoglobin concentration, the target mixed venous oxygen saturation (SvO2), and the amount of oxygen consumption are included. Our formula was compared with the conventional one. MATERIAL AND METHOD: Seventy-four points of cardiopulmonary bypass data under total cardiopulmonary bypass in 33 patients were studied. Our formula's validity was re-evaluated. Then, the SvO2 values were predicted by applying the flow rate value as per conventional calculation in to our formula. RESULTS: The flow rate of our formula and the actual flow rate are well correlated (r = 0.9212). In the prediction of the SvO2 by the conventional method, 36.5% were calculated to have a SvO2 of less than 60%. Furthermore, with a hemoglobin concentration of 7 g/dl, 73.3% were calculated to have a SvO2 of less than 60%. With a body temperature of 34 degrees centigrade, 53.8% were calculated to have a SvO2 of less than 60%. On the other hand, to maintain SvO2 level at 70% by the conventional method, if the patient hemoglobin concentration was 10 g/dl, temperature should be maintained at 36 degrees centigrade, and when hemoglobin concentration is 7 g/dl, the temperature should be maintained at 33 degrees centigrade. CONCLUSION: In advanced hemodilution or tepid cardiopulmonary bypass, use of appropriate flow rate formula is recommended, which takes into account the indispensable factors such as hemoglobin levels, temperature, and the target SvO2.

Adolescent↗
PubMed2001

Activation of mouse phosphodiesterase 3B gene promoter by adipocyte differentiation in 3T3-L1 cells.

Activation of phosphodiesterase (PDE) 3B reduces free fatty acid output from adipocytes. Induction of PDE3B gene expression by adipocyte differentiation could improve insulin resistance. To examine whether the PDE3B promoter is activated by this differentiation, the 5' flanking sequence of the mouse PDE3B gene was isolated. The transcription initiation site was determined to be located 195 bp upstream of the translation start site. No putative binding site for peroxisome proliferator-activated receptor gamma was found within 2 kb upstream of the transcription initiation site. This region had promoter activity, which was further activated on adipocyte differentiation in 3T3-L1 cells.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed2001

Systematic search for single nucleotide polymorphisms in the insulin gene: evidence for a high frequency of -23T-->A in Japanese subjects.

It has recently been shown that the A/A genotype at g.-23 of the insulin gene correlates with impaired insulin secretion in response to body weight gain in subjects of European descent. To examine whether there are single nucleotide polymorphisms (SNPs) in the insulin gene associated with type 2 diabetes, all exons with their flanking sequences for 113 Japanese type 2 diabetic patients and 99 nondiabetic control subjects were analyzed using PCR direct sequencing. We have only found g.-23T --> A, 806G --> C, 1128T --> C, and 1141A --> C, which have previously been reported in alpha (A-C-C-C) and beta (T-G-T-A) alleles. The allele frequency of -23T --> A in control Japanese subjects was 97.4%, whereas that in Europeans is about 30%. The A/A genotype was found in 94 of 99 Japanese subjects (94.9%) and the allele frequencies of 806G --> C, 1128T --> C, and 1141A --> C were all 96.5%. The estimated haplotype frequencies were (A-C-C-C) (96.0%), (T-G-T-A) (2.0%), (A-G-T-A) (1.5%), and (T-C-C-C) (0.5%). No association of these SNPs or haplotypes with type 2 diabetes was evident. Thus, the A/A genotype at the g.-23 of insulin gene was generally high in Japanese subjects, which could account for the fact that they typically secrete lower levels of insulin.

Adult↗
PubMed2001

Prevention of surgical site infection by antibiotic spraying in the operative field during cardiac surgery.

OBJECTIVE: Despite the many procedures introduced to prevent surgical site infection during cardiothoracic surgery, serious infections still occur. We attempted to reduce surgical site infection by spraying antibiotic solution in the operative field--a procedure since introduced at 4 other Japanese institutions. METHODS: In the latter half of 1990, we began spraying an antibiotic solution of cefazolin (1g) and gentamicin (40 mg)/40 ml of saline placed in a 50 ml syringe and dispensed through an 18 G needle bent at 60 to 80 degrees to clean the wound during surgery. RESULT: No deep surgical site infections or deaths due to infection have occurred among the 502 patients undergoing cardiothoracic surgery under cardiopulmonary bypass at our hospital. This method was used in over 2,100 cases of similar procedures at 4 other institutions. There were 3 deaths due to severe surgical site infection (0.11%). At one institution treating over 1,000 cases a year, the incidence of death due to surgical site infection decreased significantly after this method was introduced. CONCLUSION: These preliminary experiences show that spraying antibiotic solution in the operative field reduces the risk of surgical site infection in cardiothoracic surgery.

Aerosols↗
PubMed2001

Phosphodiesterase 3B gene expression is enhanced in the liver but reduced in the adipose tissue of obese insulin resistant db/db mouse.

Phosphodiesterase (PDE) 3B, when activated by insulin, causes a decrease in intracellular cAMP concentration. The activation of this enzyme results in the reduced output of free fatty acids (FFA) from adipocytes, and an increased lipogenesis in liver. We have recently shown that PDE3B gene expression is reduced in adipose tissues of KKAy mice. We intend to further elucidate the regulation of PDE3B in liver as well as adipose tissues in relation to the insulin resistant state. We examined PDE3B gene expression in liver and adipose tissues of obese, insulin-resistant diabetic db/db mice and also checked the effect of an insulin-sensitizing drug, troglitazone, on this gene expression. In the liver of db/db mice, PDE3B mRNA, its corresponding protein, and the associated catalytic activity were all increased by 2.1, 1.9 and 1.6-fold, respectively, over those in db/+ control mice. Histological examination revealed substantial triglyceride storage in the liver of db/db mice. Conversely, in the adipose tissue of db/db mice, PDE3B mRNA, protein, and its associated activity were all decreased by 0.38, 0.33 and 0.36-fold, respectively. Troglitazone, which has no effect on PDE3B in liver, increased the expression of this gene in adipocytes. This increase is associated with a reduction in the elevated levels of serum insulin, glucose, FFA and triglycerides. The reduced PDE3B gene expression in adipose tissues, which results in the elevation of serum FFA, could be the primary event in the development of insulin resistance in db/db mice. The enhanced PDE3B gene expression may correlate with changes in triglyceride storage in the liver of these mice.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed2001

Comparative analysis of colonization of Helicobacter pylori and glycolipids receptor density in Mongolian gerbils and mice.

The Mongolian gerbil has been used as an excellent experimental animal model for studying Helicobacter pylori infection because it can stably colonize and induce severe chronic gastritis, ulceration, and cancer-simulating human diseases in this animal. In contrast, H. pylori can only induce mild inflammation in many mouse models. The aim in this study is to clarify the difference of induction of pathological lesions in the two animal models. SPF ICR mice and Mongolian gerbils were inoculated with a clinically isolated strain of H. pylori. Six weeks after inoculation, bacteria colonizing the stomach were counted. Immunohistochemical staining and biochemical analyses of three putative receptor glycolipids were performed with monoclonal antibodies to the respective glycolipids. Significantly higher numbers of H. pylori were recovered from the stomachs of Mongolian gerbils than mice (5.77 +/- 0.46 log CFU vs 4.17 +/- 0.55 log CFU, P < 0.01). Immunohistochemical studies showed that sulfatide expression in the gastric mucosa of Mongolian gerbils was much stronger than that in mice, whereas the expression of Lewis(b) glycolipid and GM3 were almost equal. Quantitative analysis of each glycolipid by thin-layer chromatography confirmed the results of immunohistochemical study, showing 4.1 times higher sulfatide content in the Mongolian gerbil stomach. The content of both Lewis(b) and GM3 was almost equivalent in these two animals. In conclusions, higher levels of sulfatide expression, a putative adhesion receptor, in the gastric mucosa of Mongolian gerbils may allow abundant colonization by H. pylori, resulting in the development of gastric lesions in this animal model.

Animals↗
PubMed2001

Identification of novel C253Y missense and Y864X nonsense mutations in the insulin receptor gene in type A insulin-resistant patients.

Mutations in the insulin receptor gene have been reported in cases of type A insulin resistance. We report herein two cases of type A insulin resistance, which involve some novel mutations. Case 1 is a heterozygote of the C253Y missense mutation and case 2 is a heterozygote of the Y864X nonsense mutation. In the C253Y missense mutation in exon 3, a cysteine residue is replaced with tyrosine in the cysteine-rich domain of the alpha subunit. The Y864X in exon 13 results in a truncated receptor, which is devoid of most of the beta subunit. This mutant receptor could not be expressed on a cell membrane since the transmembrane domain is missing. Other significant mutations were not found for the entire coding regions and splice/donor sites.

Adolescent↗
PubMed2001

Interleukin-1beta is an autocrine growth factor of rat glomerular epithelial cells in culture.

BACKGROUND: The proliferation of glomerular epithelial cells (GEC) is usually observed in crescentic glomerulonephritis. However, the regulation of GEC proliferation is not fully understood. Although it is known that interleukin-1beta (IL-1beta) has a mitogenic effect on mesangial cells and is produced by mesangial cells, the effect of this cytokine on GEC proliferation is not known. We investigated whether cultured rat GEC could produce IL-1beta, and the role of IL-1beta on GEC proliferation. METHODS: Cultured rat GEC from 24th to 36th passage were used. GEC proliferation was evaluated with a colorimetric assay using the tetrazolium salt. GEC were incubated in K1 medium for 72 h and IL-1beta in the culture supernatants was measured by specific enzyme-linked immunosorbent assay (ELISA). IL-1beta in GEC supernatants was examined by immunoblot analysis. IL-1beta mRNA expression in GEC was examined by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: IL-1beta showed a mitogenic effect on GEC, while interferon-gamma (IFN-gamma) and heparin inhibited GEC proliferation. Moreover, GEC proliferation cultured with K1 medium was partially inhibited by anti-IL-1beta neutralizing antibody. Amounts of IL-1beta in the culture supernatants increased over time (24-72 h). K1 medium increased IL-1beta production by GEC, while IFN-gamma or heparin did not change IL-1beta production. Immunoblot analysis revealed 17 kD protein of IL-1beta in the concentrated GEC supernatants. RT-PCR also demonstrated mRNA expression of IL-1beta in GEC. CONCLUSIONS: Our data indicate that IL-1beta is an autocrine growth factor for GEC and may have an important role in the regulation of GEC proliferation.

3T3 Cells↗
PubMed2001

Cultured rat glomerular epithelial cells show gene expression and production of transforming growth factor-beta: expression is enhanced by thrombin.

BACKGROUND: Glomerular crescents play an important role in progressive glomerular injury. The lesions consist of epithelial cells, macrophages, and deposits of fibrin and extracellular matrix. Transforming growth factor beta (TGF-beta) contributes to the modulation of cell growth and extracellular matrix synthesis. Thrombin is involved in fibrin formation in crescents. The purpose of this study was to examine whether glomerular epithelial cells (GEC) could produce TGF-beta, and if so, to clarify the role of TGF-beta in GEC proliferation. We also investigated whether thrombin could modulate the production of TGF-beta and extracellular matrix by GEC. METHODS: Bioassay using the TGF-beta-dependent mink pulmonary epithelial cell line (CCL-64), immunoblot analysis, and reverse transcriptase polymerase chain reaction (RT-PCR) were used to demonstrate TGF-beta production by rat GEC. TGF-beta gene expression was examined by RT-PCR in GEC incubated with thrombin, and type IV collagen and fibronectin were quantified by enzyme immunoassay in culture supernatants of GEC incubated with thrombin or TGF-beta. RESULTS: TGF-beta activity was demonstrated in GEC supernatants by bioassay. Immunoblot analysis of concentrated culture supernatants using anti-TGF-beta antibody revealed a 12.5-kDa protein, which was compatible with TGF-beta. Concentrated GEC supernatants inhibited GEC proliferation as well as porcine TGF-beta. RT-PCR demonstrated TGF-beta gene expression in GEC. Thrombin (0.5-5.0 U/ml) enhanced TGF-beta mRNA expression in a dose-dependent manner. Thrombin (5.0 U/ml) and porcine TGF-beta (5.0 ng/ml) stimulated the production of type IV collagen and fibronectin by GEC. CONCLUSIONS: Rat GEC produce TGF-beta in vitro. Thrombin may participate in the progression of glomerulosclerosis in crescentic glomerulonephritis through the stimulation of TGF-beta production by GEC.

Animals↗
PubMed2001

Possible involvement of protein phosphorylation in aluminum-responsive malate efflux from wheat root apex.

In many plants, efflux of organic anions from roots has been proposed as one of the major Al resistance mechanisms. However it remains unknown how plants regulate efflux of organic anions in response to Al. In this study, the regulatory mechanisms of Al-responsive malate efflux in wheat (Triticum aestivum) were characterized focusing on the role of protein phosphorylation. Al-resistant wheat (cv Atlas) initiated malate efflux at 5 min after addition of Al, and this response was sensitive to temperature. K-252a, a broad range inhibitor of protein kinases, effectively blocked the Al-induced malate efflux accompanied with an increased accumulation of Al and intensified Al-induced root growth inhibition. A transient activation of a 48-kD protein kinase and an irreversible repression of a 42-kD protein kinase were observed preceding the initiation of malate efflux, and these changes were canceled by K-252a. Malate efflux was accompanied with a rapid decrease in the contents of organic anions in the root apex, such as citrate, succinate, and malate but with no change in the contents of inorganic anions such as chloride, nitrate, and phosphate. These results suggest that protein phosphorylation is involved in the Al-responsive malate efflux in the wheat root apex and that the organic anion-specific channel might be a terminal target that responds to Al signaling mediated by phosphorylation.

Aluminum↗
PubMed2001

Aluminum inhibits the H(+)-ATPase activity by permanently altering the plasma membrane surface potentials in squash roots.

Although aluminum (AL) toxicity has been widely studied in monocotyledonous crop plants, the mechanism of Al impact on economically important dicotyledonous plants is poorly understood. Here, we report the spatial pattern of Al-induced root growth inhibition, which is closely associated with inhibition of H(+)-ATPase activity coupled with decreased surface negativity of plasma membrane (PM) vesicles isolated from apical 5-mm root segments of squash (Cucurbita pepo L. cv Tetsukabuto) plants. High-sensitivity growth measurements indicated that the central elongation zone, located 2 to 4 mm from the tip, was preferentially inhibited where high Al accumulation was found. The highest positive shifts (depolarization) in zeta potential of the isolated PM vesicles from 0- to 5-mm regions of Al-treated roots were corresponded to pronounced inhibition of H(+)-ATPase activity. The depolarization of PM vesicles isolated from Al-treated roots in response to added Al in vitro was less than that of control roots, suggesting, particularly in the first 5-mm root apex, a tight Al binding to PM target sites or irreversible alteration of PM properties upon Al treatment to intact plants. In line with these data, immunolocalization of H(+)-ATPase revealed decreases in tissue-specific H(+)-ATPase in the epidermal and cortex cells (2--3 mm from tip) following Al treatments. Our report provides the first circumstantial evidence for a zone-specific depolarization of PM surface potential coupled with inhibition of H(+)-ATPase activity. These effects may indicate a direct Al interaction with H(+)-ATPase from the cytoplasmic side of the PM.

Adaptation, Physiological↗
PubMed2001

Helicobacter pylori infection and coronary heart disease in Japanese patients.

Although several independent studies have claimed a link between Helicobacter pylori infection and coronary heart disease (CHD), this association has not been established conclusively. The aim was to determine whether an association between H. pylori infection and CHD can be demonstrated in Japanese patients. Three-hundred and four patients who underwent consecutive coronary arteriography were investigated. Ninety-four patients had single-vessel coronary stenosis and 112 had multi-vessel stenosis. The remaining 98 patients had no significant stenosis in any coronary arteries. H. pylori infection was diagnosed serologically and the association between infection and CHD was estimated by the odds ratio. The serum pepsinogen (PG) I-II ratio was used to estimate the degree of gastric atrophy. Seropositivity for H. pylori was significantly higher in the patients with CHD (67%) than in the controls (50%; p = 0.006). The odds ratio for CHD after having H. pylori infection was estimated as 1.35 (95% confidence interval 1.03-1.78; p = 0.028), after adjustment for the common risk factors of CHD in a logistic regression analysis. The association between CHD and H. pylori infection was more significant among patients without any history of diabetes or smoking. The PG I-II ratio in H. pylori-positive patients was significantly higher in the multi-vessel group (3.46) than in the control or single-vessel group (2.86, p = 0.030; 2.78, p = 0.008; respectively). H. pylori infection was shown to be an independent risk factor for CHD in Japanese patients, especially among those who did not have a history of diabetes or smoking. These data imply that the association between H. pylori infection and CHD is clinically relevant.

Adult↗
PubMed2001

Adipocyte-specific reduction of phosphodiesterase 3B gene expression and its restoration by JTT-501 in the obese, diabetic KKAy mouse.

OBJECTIVE: Phosphodiesterase (PDE) 3B is a key enzyme involved in the anti-lipolytic action of insulin in adipocytes. PDE3B activation results in a reduced output of free fatty acids (FFA), whereas elevated serum FFA is known to cause insulin resistance. We have recently reported that reduced PDE3B gene expression is restored by treatment with pioglitazone, in the adipose tissues of obese, insulin-resistant diabetic KKAy mice. To determine whether the altered PDE3B gene expression is specific for adipocytes, the expression of this gene in liver and epididymal fat tissues of KKAy mice was examined. The effect of JTT-501, another peroxisome proliferator-activated receptor (PPAR)gamma ligand, which is different from thiazolidinedione, was also examined. METHODS: PDE3B mRNA and protein were quantified by an RNase protection assay and Western blotting respectively. Membrane-bound PDE activities were also measured. RESULTS: In adipose tissues of KKAy mice, PDE3B mRNA, protein and membrane-bound PDE activity were reduced to 47%, 57% and 51% respectively relative to those in C57BL/6J control mice. JTT-501 increased PDE3B mRNA, protein and membrane-bound PDE activity by 2.2-, 1.6- and 1.7-fold respectively over those of untreated KKAy mice. In the liver, PDE3B gene expression remained unchanged in KKAy mice, and was not affected by JTT-501. JTT-501 reduced the elevated levels of serum insulin, glucose, FFA and triglyceride in KKAy mice. CONCLUSIONS: PDE3B gene expression was specifically reduced in the adipose tissues of KKAy mice. JTT-501 restored this reduced gene expression with an accompanying improvement in elevated serum FFA and insulin resistance.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed2001

[Clinical significance of serum LpA-I levels measured by immunoturbidimetric assay in type 2 diabetes mellitus patients].

Previously, we developed an immunoturbidimetric assay method for lipoprotein A-I(LpA-I) on sera pre-absorbed with anti-apolipoprotein A-II. In the present study, correlations between serum lipoprotein A-I and other serum parameters levels were examined and LpA-I levels were studied in patients with type 2 diabetes mellitus. The serum levels of LpA-I did not correlate with those of diabetic markers such as fasted blood glucose, glycohemoglobin(HbA1c) and fructosamine, but correlated well with the levels of total cholesterol and HDL cholesterol, phospholipids, apolipoprotein A-I and seemed to correlate inversely with arteriosclerosis index. In patients with type 2 diabetes mellitus, LpA-I levels were significantly lower than those in normal subjects. Especially, LpA-I levels of patients with diabetic complications were significantly lower than those in normal subjects and non-complicated diabetic patients. Then, the measurement of LpA-I levels in patients with type 2 diabetes mellitus was considered to be useful for prevention and management of arteriosclerosis.

Adult↗