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Biomedical subjects

Shiro Oka

Publications and source records attributed to Shiro Oka.

16 recordsLinked to original sources

Gastrointestinal involvement in Ehlers-Danlos syndrome classical-like type 2 associated with a novel AEBP1 splice-site variant.

Ehlers-Danlos syndrome classical-like type 2 (clEDS2) is a rare autosomal recessive connective tissue disorder caused by biallelic loss-of-function variants in the gene encoding adipocyte enhancer-binding protein 1 (AEBP1). While cutaneous and skeletal manifestations are commonly observed, gastrointestinal complications, including bowel rupture, have been reported only rarely, and their histopathological basis remains poorly characterized. Here, we report findings of molecular investigations, gastrointestinal histopathological evaluation, and long-term clinical follow-up in the 16th reported patient with AEBP1-related clEDS2, complicated by spontaneous bowel perforation. A homozygous AEBP1 splice-site variant (NM_001129.5:c.1401-2 A > G) was identified by a custom next-generation sequencing-based panel analysis for hereditary connective tissue disorders. Transcript-level analysis by reverse transcription-polymerase chain reaction and Sanger sequencing demonstrated complete skipping of exon 12, resulting in a frameshift and predicted loss of function. Clinically, the patient experienced postoperative perforation in the sigmoid colon shortly after rectal cancer surgery, followed nearly 20 years later by spontaneous small intestinal perforation. Histopathological examination of the affected colonic tissue demonstrated mildly widened intermuscular spaces without other overt structural abnormalities. Notably, repeated upper and lower gastrointestinal endoscopic procedures were performed during long-term oncological surveillance without procedure-related bowel perforation. This observation could offer an opportunity to learn about gastrointestinal involvement in AEBP1-related clEDS2 and suggests that its gastrointestinal manifestations may differ in clinical context from those typically associated with vascular Ehlers-Danlos syndrome, warranting further investigation as additional cases are accumulated.

Humans↗

Lymphatic vessel density at the site of deepest penetration as a predictor of lymph node metastasis in submucosal colorectal cancer.

PURPOSE: Lymph node metastasis is an important factor that influences curability after endoscopic treatment of submucosal colorectal cancer. This study was designed to determine the usefulness of identification of lymphatic vessels by immunohistochemistry in predicting lymph node metastasis of submucosal colorectal cancer. METHODS: Lymphatic involvement was assessed by hematoxylin and eosin staining and podoplanin immunostaining on samples resected from 268 patients with submucosal colorectal cancer. Lymphatic vessel density was estimated by two investigators by average count of three fields (x200) in the area of greatest number of podoplanin-positive capillaries at the site of deepest submucosal penetration. Relations with other clinicopathologic parameters also were investigated. RESULTS: Lesions with high lymphatic vessel density (> or =9 vessels per field) showed a significantly greater incidence of lymph node metastasis than did those with low lymphatic vessel density (<9 vessels per field; 23.3 vs. 8.4 percent). By multivariate analysis, lymphatic vessel density was determined to be an independent risk factor for lymph node metastasis of submucosal colorectal cancer (P = 0.0044). Lymphatic vessel density also correlated with tumor budding and the degree of inflammation at the invasive front. CONCLUSIONS: Identification of lymphatic vessels by podoplanin immunostaining provides objective and accurate evaluation of lymphatic involvement. Lymphatic vessel density at the site of deepest penetration is a useful predictor of lymph node metastasis of submucosal colorectal cancer.

Colorectal Neoplasms↗

Advantage of endoscopic submucosal dissection compared with EMR for early gastric cancer.

BACKGROUND: In EMR of early gastric cancer (EGC), en bloc resection reduces the risk of residual cancer. Endoscopic submucosal dissection (ESD) now allows en bloc resection of large EGCs. OBJECTIVE: To retrospectively determine whether ESD is more advantageous than EMR for EGCs. DESIGN: EMR (825 lesions, 711 patients) or ESD (195 lesions, 185 patients) was performed. The en bloc resection rate, histologically complete resection rate, operation time, complications, and local recurrence rate were studied in relation to ulceration. SETTING: Hiroshima University Hospital. PATIENTS: Subjects comprised 896 patients in whom 1020 EGCs were resected endoscopically from 1990 to 2004. RESULTS: In cases without ulceration, en bloc and histologically complete resection rates were significantly higher with ESD than with EMR, regardless of tumor size. The frequency of ulceration did not differ significantly between groups. Average operation time was significantly longer for ESD than for EMR, regardless of tumor size. Also, regardless of ulceration, the incidence of intraoperative bleeding was significantly higher with ESD (22.6%) than with EMR (7.6%). Delayed bleeding did not differ. In cases with ulceration, the incidence of perforation was significantly higher with ESD (53.8%) than with EMR (2.9%). Local recurrences were treated by incomplete EMR (en bloc, 2.9%; piecemeal, 4.4%). No patient experienced recurrence after ESD. CONCLUSIONS: ESD increased en bloc and histologically complete resection rates and may reduce the local recurrence rate. Increased operation time and complication risks with ESD in comparison with EMR remain problematic. Special measures are necessary for ESD of ulcerated lesions to reduce the rates of perforation and incomplete resection.

Biopsy↗

The effect of Helicobacter pylori eradication therapy on gastric ulcer healing after endoscopic mucosal resection.

BACKGROUND AND AIM: It remains unclear whether Helicobacter pylori eradication therapy accelerates the healing of acute gastric ulcer after endoscopic mucosal resection (EMR) of gastric tumor. We examined the effect of H. pylori eradication therapy on ulcer healing after EMR. METHODS: Twenty-six patients who underwent successful H. pylori eradication therapy before EMR were followed prospectively. Patients underwent endoscopic examination 1 or 2 months after EMR, during which the ulcer status and reduction rate were assessed. The effect of H. pylori eradication on the quality of ulcer healing was also evaluated. Six patients in whom eradication therapy failed and 26 patients who underwent EMR without eradication therapy served as control subjects. RESULTS: Endoscopically, 18 (75%) of 24 ulcers in the eradication group were at the healing stage 1 month after EMR. The ulcer reduction rates were 85.0 +/- 2.6% and 96. 9 +/- 1.1% at 1 and 2 months after EMR, respectively. Ulcer stage and reduction rate did not differ significantly between the eradication group and control group. However, we frequently observed a better quality of ulcer healing in the eradication group than in the control groups (P < 0.01). CONCLUSION: H. pylori eradication therapy does not accelerate ulcer healing after EMR but may improve the quality of ulcer healing of gastric ulcer after EMR.

Aged↗

Remarkable reduction or disappearance of retroodontoid pseudotumors after occipitocervical fusion. Report of three cases.

Retroodontoid or periodontoid pseudotumor unassociated with rheumatoid arthritis or hemodialysis is clinically rare. The authors report three cases of retroodontoid pseudotumor that they treated surgically. All patients exhibited myelopathy of the upper cervical spinal cord. Plain radiography depicted atlantoaxial instability in two of the three patients. Spinal cord compression caused by a mass lesion in all patients was clearly demonstrated on magnetic resonance images. In two patients, the mass lesion was not limited to the retroodontoid region and expanded continuously to the cranial base. Posterior laminectomy of the atlas and occipitocervical fusion were performed. After surgery, the pseudotumor disappeared in two cases and was clearly reduced in one case, and neurological symptoms also improved. Retroodontoid pseudotumor is a lesion for which symptomatic improvement can be expected with posterior decompression and fusion, even without direct tumor excision.

Aged↗

Clinicopathologic and endoscopic features of colorectal serrated adenoma: differences between polypoid and superficial types.

BACKGROUND: Serrated adenoma is a distinct histologic colorectal lesion. There are two macroscopic types: polypoid and superficial. The aim of this study was to clarify clinicopathologic and endoscopic differences between polypoid and superficial serrated adenomas. METHODS: An analysis was conducted of the clinicopathologic and endoscopic features for 240 polypoid and 127 superficial serrated adenomas examined by colonoscopy, and the surface pit patterns of 114 polypoid and 64 superficial serrated adenomas examined by magnifying videoendoscopy. RESULTS: The male:female gender ratio for the polypoid serrated adenomas (3.5:1) was significantly higher than that for the superficial serrated adenomas (1.7:1). Superficial serrated adenomas were significantly larger than polypoid serrated adenomas (mean [standard deviation], respectively, 10.1 [7.9] mm vs. 6.3 [4.6] mm). In the distal segments of the colorectum, polypoid serrated adenomas were more common than superficial serrated adenomas. Granulonodular and lobular appearances at endoscopy were significantly more common for polypoid (23.3%) than for superficial serrated adenomas (7.1%). Pit patterns differed between the lesion types: polypoid serrated adenomas had type III(L) or IV pit patterns; all superficial serrated adenomas had the type II pit pattern. The relative frequency of occurrence of high-grade dysplasia and carcinoma in situ among superficial serrated adenomas (25.2%) was significantly greater than that among polypoid serrated adenomas (9.2%). The tubulovillous growth pattern was significantly more common in polypoid tumors (31.5%) than in superficial tumors (0%). CONCLUSIONS: Polypoid and superficial serrated adenomas have different clinicopathologic characteristics and growth patterns.

Adenoma↗

Initial experience with catheter probe US when using a multibending endoscope.

BACKGROUND: High-frequency catheter probe US provides detailed images when the scanning plane is perpendicular to the area of interest and the latter is within the focal zone. A multibending endoscope has been developed that has two bending sections that can be deflected independently. The aim of this study was to determine whether this new endoscope enhances high-frequency catheter probe US. METHODS: High-frequency catheter probe US was performed with the multibending endoscope in 33 patients with upper-GI lesions. The endoscope was carefully maneuvered until the scanning plane was perpendicular to the area of interest and the target area was within the focal zone of the probe. The effects of deflecting the second bending section on the image and on the rotating elements in the probe were evaluated. RESULTS: For 28 lesions, no improvement was observed with use of both bending sections. However, for 5 lesions, the US image was improved by use of the second bending section. These lesions were located in the stomach on the lesser or greater curve. In no instance did deflection of both bending sections result in uneven rotation of the mechanical elements in the probe. CONCLUSIONS: For certain lesions, US images obtained with a catheter probe can be improved by using an endoscope with a second bending section.

Catheterization↗

Clinical significance of angiopoietin-2 expression at the deepest invasive tumor site of advanced colorectal carcinoma.

Angiopoietin (Ang)-2 and vascular endothelial growth factor (VEGF) are thought to be critical regulators in tumor angiogenesis. We investigated the clinical significance of Ang-2 expression at the deepest invasive tumor site under the influence of VEGF expression in relation to angiogenesis, invasive/metastatic potential, and prognosis of advanced colorectal carcinoma (CRC). One hundred and fifty-two patients who underwent surgical resection for advanced CRC were enrolled in this study. Ang-2 and VEGF expression were examined immunohistochemically. Tumor microvessel density (MVD) was examined by immunohistochemical staining against CD34. Ang-2 and VEGF were expressed at the deepest invasive tumor site in 90 (59.2%) and 64 (42.1%) of 152 lesions, respectively. Patients with Ang-2 expression at the deepest invasive tumor site showed significantly (p<0.01) more frequent poorly histologic grade (71.9%), lymphatic involvement (65.9%), venous involvement (69.1%), lymph node metastasis (75.0%), liver metastasis (80.0%) and advanced disease (Dukes' stage C, 70.2%; stage D, 80.0%) than patients without Ang-2 expression. MVD was not significantly up-regulated by Ang-2 expression alone at the deepest invasive tumor site but was significantly up-regulated by VEGF expression at the deepest invasive tumor site under the positive-Ang-2 condition. In patients treated by curative surgery, patients with tumors showing both positive-Ang-2 and positive-VEGF condition at the deepest invasive tumor site had significantly poorer prognoses than patients with tumors under other conditions. Multivariate analysis with logistic regression for 5-year survival in cases of curative surgery showed that lymph node metastasis, VEGF expression and Ang-2 expression were significant factors to predict poor prognosis. Our results suggest that Ang-2 expression in collaboration with VEGF expression at the deepest invasive tumor site may result in tumor angiogenesis and that these angiogenic factors at the deepest invasive tumor site may be correlated with invasive/malignant potential and prognosis of advanced CRC.

Adenocarcinoma↗

Clinical significance of thrombospondin-1 expression in relation to vascular endothelial growth factor and interleukin-10 expression at the deepest invasive tumor site of advanced colorectal carcinoma.

Various angiogenic and angiostatic factors regulate angiogenesis. Tumor angiogenesis is a complicated process for which the detailed mechanisms remain unclear. The aim of this study was to elucidate the clinical significance of TSP-1 expression in relation to expression of VEGF and IL-10 and angiogenesis at the deepest invasive tumor site as a predictor of invasive/metastatic potential and prognosis of advanced colorectal carcinoma (CRC). Patients (n=152) who had undergone surgical resection for advanced CRC were entered in this study. Expression of TSP-1, VEGF, and IL-10 was examined immunohistochemically with specific antibodies. Tumor microvessel density (MVD) was also determined immunohistochemically with anti-CD34 antibody (NU-4A1). Expression of TSP-1, VEGF, and IL-10 at the deepest invasive tumor site was detected in 46 (30.3%), 62 (40.8%), and 39 (25.7%) of 152 lesions, respectively. TSP-1, VEGF, and IL-10 expression at the superficial part was detected in 60 (39.5%), 35 (23.0%), and 46 (30.3%) of 152 lesions, respectively. Although there was no significant difference between the incidence of TSP-1 and IL-10 expression at the deepest invasive site or at the superficial part, there was a significant difference between the incidence of VEGF expression at the deepest invasive site and that at the superficial part. Expression of TSP-1 and IL-10 at the deepest invasive tumor site was inversely correlated with metastatic potential and prognosis in relation to MVD. Furthermore, lesions that were TSP-1-negative and VEGF-positive at the deepest invasive tumor site showed the strongest association with MVD. The 5-year survival rate for patients with TSP-1-negative or IL-10 negative lesions at the deepest invasive tumor site was significantly poorer than that for patients with TSP-1-positive or IL-10-positive lesions, respectively. The 5-year survival rate for patients with VEGF expression at the deepest invasive tumor site was significantly poorer than that for patients without VEGF expression. The 5-year survival rate for patients with TSP-1-negative, VEGF-positive lesions at the deepest invasive site were significantly poorer than that for patients with lesions without these characteristics. Multivariate analysis with logistic regression for 5-year survival in patients with curative surgery showed that lymph node metastasis and VEGF expression were significant prognostic factors. Although lack of TSP-1 or IL-10 expression was associated significantly with poorer prognosis, this may be less important in poorer prognosis than the presence of VEGF expression.

Aged↗

Enhanced expression of PP1gamma1, a catalytic subunit isoform of protein phosphatase type1 and expression of telomerase activity in Ewing's sarcoma cells.

We previously reported that PP1gamma1 is highly expressed in osteosarcoma and chondrosarcoma, and suggested that this protein plays a role in malignancy of osteogenic tumors. In this study, we investigated the correlation of the expression of PP1gamma1 with telomerase activity. PP2A protein was not positive in any of the 5 cases of Ewing's sarcoma, but PP1gamma1 protein was strongly positive in all cases. Furthermore, malignant cells had high telomerase activity. We investigated the correlation of the expression of PP1gamma1 with telomerase activity, and showed that telomerase activity is regulated by protein phosphorylation in Ewing's sarcoma cells.

Chondrosarcoma↗

Clinicopathologic features and endoscopic resection of early primary nonampullary duodenal carcinoma.

Early primary nonampullary duodenal carcinoma is an extremely rare disease with poorly defined clinicopathologic features; early detection of this carcinoma is not common. To clarify the clinicopathologic characteristics of early primary nonampullary duodenal carcinoma and retrospectively analyze methods of treatment. Seventeen early duodenal carcinomas identified between 1994 and 2001 in 15 patients were studied. Lesions were divided into 2 groups: sporadic carcinoma (10 cases in 10 patients) and familial adenomatous polyposis associated carcinoma (7 cases in 5 patients). Clinicopathologic features and methods of treatment were compared between groups. The mean age of patients with sporadic carcinoma (63.8 years) was significantly higher than that of patients with FAP-associated carcinoma (34.9 years). The incidence of sporadic carcinoma was significantly higher in men that in women (M:F ratio 9:1); the difference between sexes in the incidence of FAP-associated carcinoma (1:4) was not significant. There was no significant difference between both groups in relation to tumor size, location, gross appearance, or histopathology. Thirteen of the duodenal tumors were treated by endoscopic mucosal resection (EMR), two by polypectomy, and two by open surgery. Complications were encountered in 1 of 15 cases (6%); local bleeding occurred after one EMR, but hemostasis was achieved endoscopically. The mean follow-up period for all patients was 51.7 months. No patients experienced recurrence after resection. The significant differences between patients with sporadic and those with early FAP-associated duodenal carcinoma were in age and sex. Endoscopic resection appears to be a safe and efficient treatment of carefully selected patients with early primary nonampullary duodenal carcinoma.

Adenomatous Polyposis Coli↗

Clinical significance of angiogenesis in rectal carcinoid tumors.

This study was designed to examine angiogenesis in rectal carcinoid tumors in relation to the clinicopathologic features. Seventy-seven rectal carcinoid tumors were studied clinicopathologically and experimentally. Cellular proliferation and microvessel density (MVD) were examined immunohistochemically. We used the antibodies MIB-1 for Ki-67, DO7 for p53, and NU-4A1 for CD34 expression in this study. Ki-67 labeling index (LI) of all lesions was below 3%, and the median Ki-67 LI of all lesions was 0.68+/-0.70% (mean +/- SD). A correlation was recognized between tumor size, metastasis and Ki-67 LI (p<0.05). Median MVD of all lesions was 25.9+/-13.1 (mean +/- SD). MVD was correlated with the tumor size (p<0.01), presence of depression (p<0.01), lymphatic (p<0.01) or venous (p<0.05) invasion, and existence of metastasis (p<0.01). But there was no significant relationship between MVD and Ki-67 LI. p53 protein was detected sporadically in only 1 case (1.3%) demonstrating both liver and lymph node metastases. Rectal carcinoid tumors are slow-growing tumors with a lower proliferative activity. Angiogenesis plays an important role in progression of rectal carcinoid tumors independent of the cellular proliferative activity.

Antigens, CD34↗

Determining depth of invasion by VN pit pattern analysis in submucosal colorectal carcinoma.

The aim of this study was to clarify whether the pit pattern on the surface of submucosal colorectal carcinoma is associated with level of invasion. We examined the VN pit-pattern (loss or decrease of pits with an amorphous structure) area of the tumor surface in 18 submucosal carcinomas that were classified based on gross appearance as either superficial or broad based sessile polypoid tumors. Pit pattern determination was made according to a previously reported system. We then evaluated the relation between the VN pit-pattern area, the maximum diameter of the VN pit-pattern area obtained stereoscopically after resection, and the depth of submucosal invasion. There was a significant correlation between the area and maximum diameter of the VN pit-pattern segment. There was also significant correlation between the maximum diameter of the VN pit-pattern area and the depth of submucosal invasion. Lesions with a maximum VN pit-pattern area diameter <5 mm showed a depth of submucosal invasion of <1500 microm. In submucosal colorectal carcinoma of the superficial or broad based sessile polypoid type in gross appearance, measurement of the maximum VN pit-pattern area diameter allows estimation of the depth of submucosal invasion.

Carcinoma↗