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Ichiro Sakamoto

Publications and source records attributed to Ichiro Sakamoto.

At least 37 records · Page 2Linked to original sources
PubMed2004

Mutational analysis of the BAK gene in 192 advanced gastric and colorectal cancers.

The evasion of apoptosis has been linked to the development of cancer. A recent study of a small number of gastric and colorectal cancers found that the BAK gene, which encodes a pro-apoptotic protein, contained somatic mutations in approximately 17% of the samples analyzed. To investigate the precise frequency of BAK mutations, we examined the entire coding sequence of the BAK gene in gastric and colorectal cancers, using polymerase chain reaction-single-strand conformational polymorphism (PCR-SSCP) analysis and direct sequencing. We could not detect any somatic mutations of the BAK gene in 192 colorectal and gastric cancers. We found only four single-nucleotide substitutions in the coding sequences, which were also found in corresponding normal samples. We conclude that somatic alterations of the BAK gene are rare in colorectal and gastric cancers.

Apoptosis↗
PubMed2003

Thrombus removal with a temporary vena caval filter in patients with acute proximal deep vein thrombosis.

Between September 1999 and January 2001 we performed thrombus removal with the use of a temporary vena caval filter in 11 patients who had acute iliofemoral venous thrombosis. To facilitate thrombus removal, 5 patients initially received catheter-directed thrombolytic therapy (thrombolysis group), and the other 6 received surgical thrombectomy (thrombectomy group). Residual thrombus was confirmed after initial catheter-directed thrombolysis in all patients in the thrombolysis group, and thrombolysis was continued in the ward. Bleeding complications subsequently occurred in 2 patients. In the thrombectomy group, 1 patient had residual thrombus just below the temporary filter, and a permanent vena caval filter was deployed for removal. Another patient had a residual thrombus in the superficial femoral vein, and rethrombectomy was performed. One patient in the thrombectomy group died of pneumonia. All other patients were discharged. There were no deaths from pulmonary thromboembolism in this series. Post-thrombotic syndrome occurred in 2 of the 5 patients in the thrombolysis group (40%) and in 3 of the 6 patients (50%) in the thrombectomy group. We conclude that a temporary vena caval filter is useful for the management of acute proximal deep vein thrombosis, especially when aggressive treatment is required.

Acute Disease↗
PubMed2003

A randomized controlled trial of therapeutic exercise for clicking due to disk anterior displacement with reduction in the temporomandibular joint.

Therapeutic exercise is a new concept of treatment for patients with clicking due to anterior disk displacement with reduction (ADDWR). In order to investigate the efficacy of the exercise, we designed a randomized controlled clinical trial to compare with no-treatment controls. The subjects were patients who complained of painless unilateral reciprocal clicking and were diagnosed as having ADDWR by Magnetic Resonance Imaging (MRI). Forty-two patients were randomly assigned. Three months after the randomization, the success rate was 61.9% (13/21 joints) in the exercise group and 0% (0/21 joints) in the control group, with a significant difference between the two groups (p=0.0001). However, captured disks in the successful cases were seen in only 23.1% on MRI examination. In conclusion, the therapeutic exercise for clicking due to ADDWR is significantly effective in reducing the clicking, and thought to be much more conservative and cost-effective than splint therapy or surgery.

Adolescent↗
PubMed2003

Magnetic resonance imaging features of aortic diseases.

The usefulness of magnetic resonance imaging (MRI) for aortic diseases is discussed, with special attention given to the MRI features of aortic dissection and Takayasu arteritis. Computed tomography (CT) and MRI provide excellent visualization of vessels and their relationship to surrounding structures; however, CT depicts the vessel lumen optimally only when contrast enhancement is used. MRI, with its inherent multiplanar imaging capability, is well suited for evaluation of the thoracic and abdominal aorta and can be used with or without contrast enhancement. Basic technical considerations in cardiac imaging, which include conventional spin-echo, fast spin-echo, cine gradient, and echo-planar imaging, with time-of-flight and phase-contrast methods, are discussed and applied to aortic aneurysm, aortic dissection, and Takayasu arteritis. The diagnostic capacity of spin-echo MRI in patients with suspected aortic dissection is enhanced when it is combined with cine MRI. Despite the ability of CT and MRI to demonstrate luminal and mural changes of aortic abnormalities, conventional angiography still may be necessary at first admission for selected patients in the late occlusive phase to provide additional information on the degree and extent of the arteritis. CT angiography and MR angiography are promising imaging techniques that will overcome difficulties in visualizing distal branch vessel lesions and obviate the need for conventional angiography in the near future.

Aortic Diseases↗
PubMed2003

Spontaneous rupture of an aneurysmal intrarenal arteriovenous fistula.

We present a 65-year-old woman who was found to have a spontaneous rupture of an aneurysmal intrarenal arteriovenous fistula. To our knowledge, the present case is only the 3rd reported in the literature. The preferred method of treatment of ruptures of arteriovenous fistulae is embolization. However, the process of choosing among embolization, surgery, or a combination of both procedures must be individualized for each patient based on vital signs and symptoms.

Aged↗
PubMed2003

Chronic aortic dissection complicated by disseminated intravascular coagulation: successful treatment with endovascular stent-grafting.

PURPOSE: To report endovascular repair of a chronic aortic dissection complicated by disseminated intravascular coagulation (DIC). CASE REPORT: A 61-year-old man developed DIC associated with a chronic Stanford type B aortic dissection that occurred during cardiac catheterization 12 years earlier. At the current admission, computed tomography showed a partially thrombosed false lumen extending from the aortic arch to the left common iliac artery. On angiography, entry and re-entry tears were identified at the right subclavian and left common iliac arteries, respectively. After stent-graft implantation at the entry and re-entry sites, not only was the false lumen completely thrombosed but the DIC also resolved. The patient is doing well with no complication at 16 months after treatment. CONCLUSIONS: Endovascular stent-grafting is an acceptable alternative to surgical repair for aortic dissection accompanied by DIC.

Aortic Dissection↗
PubMed2003

Coil embolization of iliac artery aneurysms developing after abdominal aortic aneurysm repair with a conventional bifurcated graft.

PURPOSE: To evaluate the efficacy of embolizing iliac artery aneurysms (IAAs) developing after abdominal aortic aneurysm (AAA) repair. METHODS: The records of 6 patients (5 men; mean age 79 years, range 61-87) with unilateral (n=3) or bilateral (n=3) IAAs that had developed after AAA repair were reviewed. In all patients, the limbs of the bifurcated graft were anastomosed end-to-end or end-to-side with the external iliac arteries during AAA repair. Before embolization, superior mesenteric artery (SMA) arteriography was done in all patients to evaluate collateral pathways to the inferior mesenteric artery (IMA). RESULTS: The unilateral IAAs were treated by proximal and distal embolization. In 2 patients with bilateral IAAs, SMA angiography showed sufficient collateral flow to the IMA, so the aneurysms were treated by proximal embolization and packing. In the other bilateral IAA case, the left 6-cm IAA was treated by proximal and distal embolization, while the contralateral 3-cm IAA was not embolized because angiography demonstrated inadequate collateral flow to the IMA, indicating a possible risk of colon ischemia if both IAAs were embolized. Immediate postprocedural angiography in all patients showed complete exclusion of the IAAs. Mild buttock claudication occurred in 1 patient. There were no episodes of rupture over a mean 46-month follow-up. CONCLUSIONS: Embolization is a safe and effective alternative to open surgery for the treatment of IAAs that develop after AAA repair. However, before embolization, angiographic evaluation of collateral pathways to the IMA is essential to reduce the risk of colon ischemia.

Aged↗
PubMed2003

Intrahepatic biloma formation (bile duct necrosis) after transcatheter arterial chemoembolization.

OBJECTIVE: The purpose of our study was to discuss the incidence, predisposing factors, and clinical course of intrahepatic biloma after transcatheter arterial chemoembolization for hepatic tumors including hepatocellular carcinoma and metastatic liver tumor. MATERIALS AND METHODS: Nine hundred seventy-two patients with hepatocellular carcinoma (n = 920) or metastatic liver tumor (n = 52) underwent chemoembolization during a 12-year period beginning in January 1989. We retrospectively reviewed the medical records and follow-up radiographs of chemoembolization and analyzed the risk factors associated with the development of intrahepatic biloma. RESULTS: Intrahepatic biloma developed after chemoembolization in 35 patients (3.6%, 35/972) in our series. The incidence of intrahepatic biloma formation in patients with metastatic liver tumor (9.6%, 5/52) was higher than that in patients with hepatocellular carcinoma (3.3%, 30/920) (p < 0.05, Fisher's exact test). The incidence of intrahepatic biloma formation in patients with hepatocellular carcinoma was statistically higher in patients with main tumor size of less than 5 cm and in those with the presence of intrahepatic bile duct dilatation. Technique-related risk factors such as injection site of drugs, repeated chemoembolization with frequency of less than 3 months, and regimen of chemoembolization significantly influenced the incidence of biloma formation in patients with hepatocellular carcinoma. No patient died of infected biloma or septicemia, but one patient died of hepatic failure 2 months after chemoembolization. CONCLUSION: Biloma formation was significantly more prevalent in the metastatic lesion group than in the hepatocellular carcinoma group. Significant prognostic factors for biloma formation in patients with hepatocellular carcinoma were tumor size of less than 5 cm, bile duct dilatation, proximal injection site, repeated injection with frequency of less than 3 months, and injection of a suspension of anticancer drugs.

Aged↗
PubMed2002

Frameshift mutations in the MBD4/MED1 gene in primary gastric cancer with high-frequency microsatellite instability.

MBD4/MED1 is a newly identified mismatch repair gene, which is mutated in colon, endometrial, and pancreatic high-frequency microsatellite instability (MSI-H) tumors. To assess its role in gastric cancers, we investigated MBD4/MED1 mutations in sporadic gastric cancers, compared with colon cancers. Frameshift mutations were found in 29% of gastric and 20% of colon MSI-H cancers, but not in any low-frequency microsatellite instability/microsatellite stable cancers. MBD4/MED1 is mutated in gastric cancers as frequently as in colon cancers; these mutations reduce the accuracy of DNA repair, and may lead to cancer progression.

Aged↗
PubMed2002

Computed tomographic findings of colorectal liver metastases can be predictive for recurrence after hepatic resection.

BACKGROUND: We recently reported that the pathologic mode of infiltrative growth (infiltrative [INF]-alpha, INF-beta, and INF-gamma) of colorectal liver metastases had characteristic morphologic findings, and furthermore showed that the INF type was a prognostic factor for disease-free survival after hepatic resection. HYPOTHESIS: Preoperative computed tomographic (CT) findings of the liver nodules may be predictive for pathologic tumor growth pattern. DESIGN: Retrospective study. SETTING: Departments of Surgery and Radiology at a university hospital in Japan. PATIENTS: A total of 25 CT examinations (1985-1998) were reviewed, and a comparison was conducted on CT findings of 2 groups with INF-alpha or INF-beta (hereafter noted as INF-alpha-beta) (n = 9 [ie, a patient with INF-alpha plus 8 with INF-beta]) and INF-gamma (n = 16) type liver metastases. MAIN OUTCOME MEASURES: chi(2) Analysis of CT morphologic features was performed between the study groups. The result of multivariate analysis was obtained using the Cox proportional hazards model. RESULTS: The morphologic features observed by CT showed a significant difference between the 2 groups (INF-alpha-beta, and INF-gamma types) in the ratio of length to breadth of nodules (<1.5 vs > or =1.5, P =.008) and in the outline of nodules (regular vs irregular, P =.01). Of these CT imaging features, the outline of the nodule was an independent prognostic factor (P =.02). CONCLUSION: Computed tomographic findings of colorectal liver lesions correlated with the pathologic tumor growth pattern and a prognosis.

Colorectal Neoplasms↗
PubMed2002

Analysis of predictive factors for progression of type B aortic intramural hematoma with computed tomography.

PURPOSE: For patients with Stanford type B aortic intramural hematoma (IMH), medical treatment is usually selected. However, the outcomes of patients with type B IMH are not completely understood, and some cases can have fatal complications develop or surgical treatment necessitated. The purpose of this study was to investigate predictors of progression of the affected aorta in patients with type B IMH with initial computed tomography (CT) images. METHODS: Thirty-five patients with type B IMH were studied with serial CT images. Initially, medical therapy was selected for all patients. CT findings of the affected aorta were evaluated on admission and at follow-up. We divided the patients into two groups (progression group or regression group) on the basis of CT findings and investigated predictors of progression of the affected aorta with initial CT images. RESULTS: We defined 15 patients who showed increased maximum aortic diameter (n = 14), increased maximum aortic wall thickness (n = 3), progression to overt dissection (n = 4), or rupture of the aortic wall (n = 2) during the follow-up period as the progression group. The other 20 patients, who all showed decreased maximum aortic wall and aortic wall thickness, were defined as the regression group. In the maximum aortic diameter, an optimal cutoff value of 40 mm resulted in positive predictive and negative predictive values of 86.7% and 90.0%, respectively. Both a maximum aortic diameter of 40 mm or more (P =.0011) and a maximum aortic wall thickness of 10 mm or more (P =.0009) were shown to be significantly predictive of the progression with Cox regression analysis. CONCLUSION: Maximum aortic diameter and maximum aortic wall thickness on initial CT images are predictive for progression of the affected aorta in patients with type B IMH. For type B IMH with a maximum aortic diameter of 40 mm or more or a maximum aortic wall thickness of 10 mm or more, careful follow-up studies must be required.

Aged↗
PubMed2002

Effect of arthrocentesis on TMJ disturbance of mouth closure with loud clicking: a preliminary study.

The objective of this study was to evaluate the short-term effect of arthrocentesis on temporomandibular joint disturbance of mouth closure with loud clicking compared to the effect of one-time pumping into the joint space previous to arthrography. Twenty-one consecutive patients (22 joints) with loud clicking during mouth closure were enrolled. All were unable to smoothly close the mouth without effort. Eleven patients (12 joints) were examined using magnetic resonance imaging (MRI) to determine disk position. They then underwent arthrocentesis. Ten patients (10 joints) underwent arthrography alone as controls. Six months later, changes in clicking and temporomandibular joint movement were analyzed and the disk position was re-examined. There was improvement of mouth closing and clicking occurred in nine joints from the arthrocentesis group and two joints from the control group, with a significant difference between the two groups. Arthrocentesis may be indicated for patients with temporomandibular joint dysfunction and loud clicking when mouth closing.

Adolescent↗
PubMed2002

New development of an ulcerlike projection in aortic intramural hematoma: CT evaluation.

PURPOSE: To investigate the natural history and predictors of progression of a newly developed ulcerlike projection in patients with an aortic intramural hematoma. MATERIALS AND METHODS: Serial computed tomographic (CT) findings in 52 patients with intramural hematoma were reviewed. Sixteen patients had Stanford type A intramural hematoma, and 36 had Stanford type B. Diagnosis of intramural hematoma was established with CT. Regular follow-up studies were performed every week during the 1st month and two or three times a year after the 2nd month. The presence or absence of an ulcerlike projection, diameter and progression of the projection, and aortic diameter were evaluated. Relationships among ulcerlike projections, clinical data, and CT findings were analyzed. RESULTS: In 17 (33%) of the 52 patients, 17 ulcerlike projections were newly identified during the follow-up period. Patients with type A intramural hematoma had a significantly higher frequency of new development of ulcerlike projection than that of patients with type B intramural hematoma (P =.002). In 17 patients with new development of ulcerlike projection, 12 (70%) of 17 projections progressed to complications such as enlargement (n = 10) or progression to overt aortic dissection (n = 2). One of 10 enlarged projections progressed to rupture. A significant predictor of progression of ulcerlike projection was based on location from the ascending aorta to the aortic arch with the use of univariate (P =.009) and multivariate Cox (P =.018) regression analyses. CONCLUSION: The location of ulcerlike projections is the principal predictor of progression, and careful follow-up study is needed for patients with an ulcerlike projection located from the ascending aorta to the aortic arch.

Adult↗
PubMed2002

Clinical and magnetic resonance imaging study of unilateral sideways disc displacements of the temporomandibular joint.

The aim of our study was to find symptomatic diagnostic factors for sideways displacement of the temporomandibular joint disc, compared with anterior or rotational disc displacement. A consecutive series of 2310 temporomandibular joints were examined with MRI to define the clinical signs and symptoms particularly related to sideways disc displacement compared to anterior disc displacement with logistic regression model. Bone change of the mandibular condyle and age were negatively related factors in differentiating cases with lateral disc displacement from anterior disc displacement without reduction. Range of mouth opening (over 40 mm) was a significant predictor (odds ratio 4.5865 for lateral disc displacement). This study suggested the wide opening of the mouth to become the predictor for the lateral disc displacement among the cases suspected to have disc displacement without reduction.

Adolescent↗
PubMedDate not supplied

Esophageal and bronchial perforations after thoracic aortic aneurysm replacement: successful repair with covered metallic stents.

Esophageal and bronchial perforations are rare but potentially fatal complications of descending thoracic aortic aneurysm replacement. This report presents a 67-year-old man with both esophageal and bronchial perforations that occurred after descending thoracic aortic aneurysm replacement. Surgical repair was performed, but the lesions perforated again. Two covered metallic stent prostheses introduced into both the esophagus and left main bronchus led to the improvement of mediastinitis by sealing the perforations. To our knowledge, this is the first report describing successful treatment for esophageal and bronchial perforations using covered metallic stents. Placement of covered metallic stents can be an option for the treatment of patients with esophagorespiratory tract perforations, especially those who are in critical condition.

Aged↗