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Toshiaki Watanabe

Publications and source records attributed to Toshiaki Watanabe.

At least 73 records · Page 4Linked to original sources
PubMed2005

[Epidemiology of ulcerative colitis--comparison between Japan and western countries].

Epidemiological data of ulcerative colitis both in Japan and other countries were presented. The prevalence has been increasing in Japan in the past few decades, although it is still lower than that reported from western countries. The incidence in Japan as well as other countries in Asia is increasing. On the other hand, the incidence in western countries has been reported to be decreasing in some reports. There seems to be no significant difference in age of onset between Japan and western countries. Cause of death in patients with ulcerative colitis has changed in Japan after 1980. Death related with colorectal cancer has been increasing in the past 25 years in Japan.

Age Factors↗
PubMed2004

Dual mode regulation of migration by lysophosphatidic acid in human gastric cancer cells.

Lysophosphatidic acid (LPA), which interacts with at least three G protein-coupled receptors (GPCRs), LPA1/Edg-2, LPA2/Edg-4, and LPA3/Edg-7, is a lipid mediator with diverse effects on various cells. Here, we investigated the expression profiles of LPA receptors and patterns of LPA-induced migration in gastric cancer cells. Northern blot analysis revealed that various gastric cancer cells expressed variable levels of LPA1, LPA2, and LPA3 without a consistent pattern. Using a Boyden chamber assay, LPA markedly increased cell migration of LPA1-expressing cells, the effects of which were almost totally abrogated by Ki16425, an LPA antagonist against LPA1 and LPA3. In contrast, LPA by itself did not significantly induce migration in MKN28 and MKN74 cells, which exclusively expressed LPA2. However, when hepatocyte growth factor (HGF) was placed with LPA in the lower chamber, LPA induced migration of these cells in a dose-dependent manner. Immunoprecipitation analysis revealed that LPA induced transient tyrosine phosphorylation of c-Met in LPA2-expressing cells, which suggests that the transactivation of c-Met by LPA causes a cooperative migratory response with HGF to these cells. Our results indicate that LPA regulates the migration of gastric cancer cells in a receptor-specific manner and suggest that the expression pattern of LPA receptors may affect the metastatic behavior of gastric cancer.

Chemotaxis↗
PubMed2004

Sphingosine 1-phosphate transactivates c-Met as well as epidermal growth factor receptor (EGFR) in human gastric cancer cells.

Receptor tyrosine kinases (RTKs) are transactivated by the stimulation of G protein-coupled receptors (GPCRs). Sphingosine 1-phosphate (S1P), a ligand of GPCR, is known as a tumor-promoting lipid, but its signaling pathways are not fully understood. We here demonstrated that S1P induces rapid and transient tyrosine phosphorylation of epidermal growth factor receptor (EGFR) and c-Met in gastric cancer cells, both of which have been proposed as prognostic markers of gastric cancers. The pathway of S1P-induced c-Met transactivation is Gi-independent and matrix metalloproteinase-independent, which differs from that of EGFR transactivation. Our results indicate that S1P acts upstream of various RTKs and thus may act as a potent stimulator of gastric cancer.

Blotting, Western↗
PubMed2004

Gastrointestinal stromal tumor of the retroperitoneum: CT and MR findings.

Gastrointestinal stromal tumor (GIST) is a non-epithelial neoplasm arising from the wall of the gastrointestinal (GI) tract. Although the majority of GISTs are located in the GI tract, some GISTs occur in the omentum, mesentery and retroperitoneum. GIST arising in the retroperitoneum is extremely rare, and its radiological findings have not been well described. We report a case of primary retroperitoneal GIST and discuss its imaging findings.

Aged↗
PubMed2004

Hemophagocytic syndrome caused by fulminant ulcerative colitis and cytomegalovirus infection: report of a case.

We report a case of hemophagocytic syndrome that developed in a 35-year-old, Japanese male with fulminant ulcerative colitis. The patient underwent an emergency operation, consisting of subtotal colectomy, ileostomy with rectal preservation (suprapubic mucous fistula). After the operation, peripheral blood counts showed progressive pancytopenia and bone marrow aspirate smears revealed hypocellular bone marrow with an increase in histiocytes, indicating hemophagocytic syndrome. Viral studies (serum antibody titer and antigenemia of cytomegalovirus) revealed systemic cytomegalovirus infection. The patient was diagnosed with virus-associated hemophagocytic syndrome and was successfully treated with antiviral therapy consisting of intravenous ganciclovir, gamma globulin, and granulocyte-colony stimulating factor.

Adult↗
PubMed2004

Successfully treated idiopathic rectosigmoid perforation 7 years after renal transplantation.

Colon perforation (CP) is still a critical complication after renal transplantation (RT), and idiopathic perforation is extremely rare. Here we describe a successfully treated case of idiopathic rectosigmoid perforation that occurred 7 years after RT. In our research this is the tenth reported case of idiopathic CP after RT and the second case that has occurred in the rectosigmoid. The patient was a 51-year-old Japanese male RT recipient still receiving immunosuppressive medication. He was admitted to the hospital for sudden onset of abdominal pain during defecation. Emergency laparotomy was performed 5 h after the onset, and a longitudinal 1.5 cm perforation with a clear margin was observed in the rectosigmoid, 8 cm above the peritoneal reflection. Hartmann's operation was performed. Macroscopic and histological examination did not reveal any specific findings that may have caused perforation, so the case was diagnosed as idiopathic rectosigmoid perforation.

Humans↗
PubMed2004

Correlations between lymph node metastasis and depth of submucosal invasion in submucosal invasive colorectal carcinoma: a Japanese collaborative study.

BACKGROUND: Depth of submucosal invasion (SM depth) in submucosal invasive colorectal carcinoma (SICC) is considered an important predictive factor for lymph node metastasis. However, no nationwide reports have clarified the relationship between SM depth and rate of lymph node metastasis. Our aim was to investigate the correlations between lymph node metastasis and SM depth in SICC. METHODS: SM depth was measured for 865 SICCs that were surgically resected at six institutions throughout Japan. For pedunculated SICC, the level 2 line according to Haggitt's classification was used as baseline and the SM depth was measured from this baseline to the deepest portion in the submucosa. When the deepest portion of invasion was limited to above the baseline, the case was defined as a head invasion. For nonpedunculated SICC, when the muscularis mucosae could be identified, the muscularis mucosae was used as baseline and the vertical distance from this line to the deepest portion of invasion represented SM depth. When the muscularis mucosae could not be identified due to carcinomatous invasion, the superficial aspect of the SICC was used as baseline, and the vertical distance from this line to the deepest portion was determined. RESULTS: For pedunculated SICC, rate of lymph node metastasis was 0% in head invasion cases and stalk invasion cases with SM depth <3000 micro m if lymphatic invasion was negative. For nonpedunculated SICC, rate of lymph node metastasis was also 0% if SM depth was <1000 micro m. CONCLUSIONS: These results clarified rates of lymph node metastasis in SICC according to SM depth, and may contribute to defining therapeutic strategies for SICC.

Adult↗
PubMed2004

Near-infrared spectroscopy with treadmill exercise to assess lower limb ischemia in patients with atherosclerotic occlusive disease.

PURPOSE: We used near-infrared spectroscopy (NIRS) to measure exercise-induced ischemia in patients with intermittent claudication, and compared these results with those obtained by ankle-brachial pressure index (ABPI) analysis. METHODS: Sixty-two patients with intermittent claudication caused by atherosclerotic occlusive disease exercised on a treadmill until reaching the maximal tolerated walking distance. We measured the ABPI at rest and after exercise until it returned to the baseline value. A NIRS probe was positioned on the patient's calf, which allowed the continuous monitoring of oxygen saturation (StO2), oxygenated hemoglobin (Oxy Hb), and deoxygenated hemoglobin (Deoxy Hb) in the calf muscles before, during, and after exercise. During exercise, the StO2 and Oxy Hb decreased, and the Deoxy Hb increased. The time taken for each measurement to return to the baseline value was defined as the recovery time. The recovery times obtained by NIRS and ABPI were compared. RESULTS: The recovery time for ABPI correlated well with that for StO(2 (rhos = 0.73), Oxy Hb (rhos = 0.63), and Deoxy Hb (rhos = 0.65); however, the recovery times measured by NIRS were shorter than the recovery time for the ABPI. CONCLUSIONS: Near-infrared spectroscopy is a reliable method for monitoring peripheral circulation during and after exercise, although the data generated provided slightly different information than the results obtained by ABPI.

Adult↗
PubMed2004

Avoiding chest tube placement after video-assisted thoracoscopic wedge resection of the lung.

OBJECTIVE: A chest tube is usually placed in the pleural cavity after wedge resection of the lung, even after thoracoscopic procedures. The aim of this study was to determine the validity and safety of postoperative management without chest tube placement for patients undergoing thoracoscopic wedge resection of the lung. METHODS: Between 1998 and 2002, 93 patients underwent thoracoscopic wedge resection of the lung. In January 2000, we established the following criteria for avoiding chest tube placement: (1) absence of air leaks during intraoperative alternative sealing test, (2) absence of bullous or emphysematous changes on inspection, (3) absence of severe pleural adhesions, and (4) absence of prolonged pleural effusion requiring chest drainage preoperatively. Seventeen of 93 patients did not satisfy the criteria. The other 76 patients were divided into two groups: group 1 consisted of 34 patients who underwent thoracoscopic resection before 1999 and in whom a chest tube was routinely placed in spite of retrospectively meeting the criteria, group 2 consisted of 42 patients who underwent thoracoscopic resection after 2000 and in whom chest tube was not placed. The clinical data were evaluated and analyzed between the two groups. RESULTS: Two patients in group 1 required new intervention after removal of a chest tube that had been inserted during the operation due to recurrence of a pneumothorax, so did two patients in group 2 after the operation. The rate of late pneumothorax requiring intervention is similar in groups 1 and 2. No differences were found between the two groups with regard to postoperative chest pain and hospital stay. No patients experienced a significant adverse outcome. CONCLUSIONS: Avoiding the chest tube placement did not increase postoperative morbidity if carefully selected criteria are met.

Adolescent↗
PubMed2004

Epigallocatechin gallate attenuates adhesion and migration of CD8+ T cells by binding to CD11b.

BACKGROUND: Although green tea polyphenol catechin has been reported to have antiallergic and anti-inflammatory activities, the precise mechanisms of its effect on the immune system have been poorly investigated. OBJECTIVE: In this study, we aimed to elucidate the mechanisms of the anti-inflammatory effect of catechin. For this purpose, we studied the effect of 2 kinds of catechin, epigallocatechin gallate (EGCG) and epicatechin gallate, on peripheral blood CD8+ T cells, which play the key role in immune responses. METHODS: Isolated peripheral blood mononuclear cells or CD8+ T cells were incubated without or with catechin, and the changes in the surface expression of integrin molecules were investigated by flow cytometry and the direct binding of catechin to CD11b molecule by competitive ELISA. Also, the effect of catechin on the ability of CD8+ T cells to bind intracellular adhesion molecule 1 and to migrate in response to chemokines was evaluated by using the adhesion and migration assays. RESULTS: The 2 catechins directly bound to CD11b expressed on CD8+ T cells, which caused a consequent decrease of flow-cytometric CD11b expression. The effect was more prominent with EGCG than epicatechin gallate, and the impaired expression of CD11b induced by EGCG resulted in decreased ability of CD8+ T cells to adhere intercellular adhesion molecule 1, and consequently decreased migration in response to chemokines. CONCLUSION: We concluded that catechin, especially EGCG, by downregulating CD11b expression on CD8+ T cells and, in consequence, inhibiting infiltration of these cells into the sites of inflammation, is a promising new potent anti-inflammatory agent.

Antigens, CD1↗
PubMed2004

Prognostic factors for myasthenic crisis after transsternal thymectomy in patients with myasthenia gravis.

OBJECTIVE: The purpose of this study was to assess which clinical features of patients with myasthenia gravis predict postoperative respiratory problems due to myasthenic crisis after transsternal thymectomy. METHODS: One hundred twenty-two patients who underwent transsternal thymectomy in our institute were analyzed retrospectively. Fourteen of those experienced myasthenic crisis and required prolonged (48 hours or more) postoperative mechanical ventilation. The following factors were evaluated: sex, age, body mass index, grade of symptom, disease interval, existence of thymoma, history of preoperative crisis, doses of anticholinesterase drugs, steroid use, pulmonary function, serum anti-acetylcholine receptor antibody, history of pulmonary disease, presence of other disease, operation time, and blood loss. RESULTS: Univariate analysis revealed preoperative bulbar symptoms (odds ratio = 14.246, P =.001), history of preoperative myasthenic crisis (7.091,.018), and preoperative serum level of anti-acetylcholine receptor antibody > 100 nmol/L (4.098,.044) were prognostic factors for postoperative myasthenic crisis. On the other hand, multivariate logistic regression analysis revealed preoperative bulbar symptoms (33.333,.004), preoperative serum level of anti-acetylcholine receptor antibody > 100 nmol/L (7.874,.020), and intraoperative blood loss > 1000 mL (18.519,.048) were prognostic factors for postoperative myasthenic crisis. CONCLUSIONS: In this study, postoperative myasthenic crisis after transsternal thymectomy in 122 patients with myasthenia gravis was affected by the existence of preoperative bulbar symptoms, history of preoperative myasthenic crisis, preoperative serum level of anti-acetylcholine receptor antibody > 100 nmol/L, and intraoperative blood loss > 1000 mL. Meticulous preoperative and postoperative care should be carried out to prevent postoperative myasthenic crisis in patients with these prognostic factors.

Adolescent↗
PubMed2004

Polyacrylamide gel containing egg white as new model for irradiation experiments using focused ultrasound.

A polyacrylamide (PAA) gel containing egg white as a new model for irradiation experiments in high-intensity focused ultrasound HIFU is introduced. The gel is transparent except in thermally necrosed regions which are white. The model is similar to, and has the same benefits as, gels containing bovine serum albumin (BSA) protein, but egg is less expensive than BSA. The acoustic properties of the gel are very favorable, similar to those of soft tissues; density 1.0 g/cm(3), sound speed 1540 m/s and acoustic attenuation 0.4 dB/cm at 2 MHz. We illustrate the usefulness of the gel in visualizing HIFU lesions and introduce a new model of gastric submucosal tumor in a rabbit stomach, showing that this gel can be formed into any desired shape. Our PAA gel containing egg white is an attractive candidate for a disposable acoustic material suitable for experimental applications of HIFU.

Acrylic Resins↗
PubMed2004

The use of a lateral stabilizer increases the incidence of wound trouble following the Nuss procedure.

BACKGROUND: A lateral stabilizer has been used to prevent bar displacement during the Nuss procedure for pectus excavatum repair in pediatric patients. We experienced wound troubles in patients who had a stabilizer placed within them. The aim of this study was to examine the effect of a lateral stabilizer and other clinical factors on wound troubles after the Nuss procedure. METHODS: 53 patients with pectus excavatum underwent repair by the Nuss procedure. Preoperative clinical data, operative data, and postoperative complications were examined in all patients. RESULTS: A lateral stabilizer was placed in 29 of the 53 patients. Short-term results were excellent in 42 patients (79.2%). Postoperative complications involved pneumothorax requiring drainage in two patients, atelectasis in one patient, pleural effusion in three patients, deterioration of scoliosis in one patient, erythema in one patient, persistent pain in two patients, bar displacement in four patients, and local wound complications (Seroma with dermatitis due to pressure damage) in five patients. All seromas with dermatitis due to pressure damage were initially aseptic around lateral stabilizers and became infected in four patients after resection of the seroma or spontaneous perforation. Removal of both the pectus bar and lateral stabilizer was performed in two of those four patients and the lateral stabilizer was removed in the other two patients to prevent catastrophic infection such as empyema or mediastinitis. The use of a lateral stabilizer increases the incidence of wound trouble (p = 0.041). CONCLUSIONS: Although the Nuss procedure has evolved into an effective method for pectus excavatum repair, the use of a lateral stabilizer increases the incidence of wound difficulties.

Adolescent↗
PubMed2004

Aberrant expression of lysophosphatidic acid (LPA) receptors in human colorectal cancer.

Lysophosphatidic acid (LPA) is a simple bioactive phospholipid with diverse effects on various cells, that interacts with three G protein-coupled transmembrane receptors, LPA1, LPA2, and LPA3. The expression pattern and functions of these LPA receptors in various tumors have not been fully examined, except in ovarian cancer. To evaluate the LPA receptor expression profile in human colorectal cancer and in normal mucosa, we used real-time reverse transcription-polymerase chain reaction (RT-PCR) and measured the expression levels of LPA1, LPA2, and LPA3 messenger RNA (mRNA) in 26 colorectal cancers and 16 corresponding normal tissue samples. Normal epithelium expressed both LPA1 and LPA2 mRNA at similar levels. In comparison, colorectal cancers expressed LPA1 mRNA at a significantly lower level (0.3-fold; P<0.05), and LPA2 mRNA at a significantly higher level (three-fold; P<0.05), as compared with normal tissues. Thus, the ratio of LPA2/LPA1 increased markedly during malignant transformation (18-fold increase). LPA3 mRNA was expressed at only a low level in both normal and cancer tissues. We also assessed LPA2 expression immunohistochemically using a rat anti-LPA2 monoclonal antibody, and confirmed high expression of LPA2 in colorectal cancer at the protein level. As for LPA1, we examined Western blot analysis for 16 matched normal and cancer tissues. It revealed a significant decrease in the expression of LPA1 protein in cancer tissues compared to normal mucosa in nine of 16 cases, and in the remaining seven cases the expression levels was much the same. These results suggested that alteration of LPA receptor expression might be an important event in the development of colorectal cancer, and therefore, LPA and its receptors could be a chemopreventive target against colorectal cancer.

Adenocarcinoma↗