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Biomedical subjects

K Shirouzu

Publications and source records attributed to K Shirouzu.

At least 91 records · Page 5Linked to original sources
PubMed1999

Histopathological findings of the lower esophagus after total gastrectomy in rat.

It is now accepted that the incidence of esophageal carcinoma is highest in the middle thoracic region. Esophageal carcinoma after gastrectomy, however, has a tendency to develop in the lower region. This study was designed to investigate the role of reflux of gastroduodenal juice in the genesis of carcinoma in the esophagus. We found a possible correlation between the development of esophageal carcinoma and gastrectomy, related to alkaline reflux into the esophagus. To elucidate this correlation, the role of alkaline reflux of duodenal contents in the development of esophageal squamous cell carcinoma was investigated in Wister rats. Gastrectomized rats with regurgitation of duodenal contents into the esophagus were not administered any carcinogen and were sacrificed some at the end of 8 weeks and others at 50 weeks for pathological examination. Hyperplasia was found in rats at 8 weeks, and the esophageal squamous cell carcinoma was found in rats at 50 weeks. The carcinomas were found exclusively in the area of the reflux esophagitis and were accompanied by severe dysplasia. These results suggested that alkaline reflux of duodenal contents was strongly correlated to the development of the esophageal squamous cell carcinoma.

Animals↗
PubMed1999

Submucosal gastric cancer with lymph node metastasis--a clinicopathological study.

We have reviewed the clinicopathological features of submucosal gastric cancer with lymph node metastasis. The degree of vertical submucosal infiltration was classified into three stages as sm1, sm2 or sm3. The number of cases with lymph node metastasis of sm3 was significantly more than that of sm1 or sm2. We found no correlation between the tumor size and the rate of lymph node metastasis from submucosal invasive cancer. Accordingly, we concluded that the vertical submucosal infiltration was a more important factor for lymph node metastasis than horizontal infiltration. Minimal invasive surgery was recommended for a tumor measuring 1 cm or less in size with vertical submucosal invasion of sm1 or sm2.

Gastric Mucosa↗
PubMed1999

Experimental and clinical evaluation of the harmonic scalpel in thoracic surgery.

The Harmonic Scalpel is an ultrasonic instrument for cutting and coagulating tissue. We are reporting our evaluation of the Harmonic Scalpel safety and efficacy in both experimental and clinical thoracic surgery. First, we confirmed the safety in thoracic surgery by following two preliminary studies using the Harmonic Scalpel. 1: Pulmonary parenchyma was incised using "Coagulating Shears" to evaluate hemostasis and air leakage. 2: Pulmonary hilar vessels were contacted directly with "Dissecting Hook" blade at optimum cutting power mode to evaluate potential vascular wall injury by the Harmonic Scalpel. Subsequently, the Harmonic Scalpel was used for a partial lung resection due to metastatic lung cancer. Particular application was for a chest wall incision, interlobar separation of the lung, and dissection of a pulmonary artery, in lung cancer operations. We concluded that cutting and hemostasis of pulmonary parenchyma could be achieved with minimal tissue damage using the Harmonic Scalpel. Compared to electric coagulation, the Harmonic Scalpel minimizes tissue charring and dissection, and eliminates thermal injury in thoracic surgery.

Animals↗
PubMed1999

In vitro B-mode ultrasonographic criteria for diagnosing axillary lymph node metastasis of breast cancer.

Axillary lymph node status is an important factor for staging and treatment planning in breast cancer. Our study was performed in vitro on a node-by-node basis to evaluate the ability of B-mode ultrasonographic images to distinguish metastatic from nonmetastatic nodes. Immediately prior to histologic examination, individual dissected axillary nodes were scanned in a water bath using a 10 MHz B-mode ultrasonographic transducer. Four B-mode features (size, circularity, border demarcation, and internal echo) were evaluated for their ability to distinguish metastatic from nonmetastatic lymph nodes. Lymph node metastasis was indicated by (1) a large size (i.e., a length of the longest axis of 10 mm or greater); (2) a circular shape (i.e., the ratio of the shortest axis to the longest axis between 0.5 and 1.0); (3) a sharply demarcated border compared with surrounding fatty tissue; and (4) a hypoechoic internal echo, with obliteration of the fatty hilum. The sensitivity and specificity were compared for all combinations of features. We examined 84 histologically characterized axillary nodes from 27 breast cancer patients, including 64 nonmetastatic and 20 metastatic nodes. Of the criteria cited, circular shape was the best single feature for distinguishing metastatic from nonmetastatic nodes (sensitivity, 65%; specificity, 73%). The best combination of sensitivity (85%) and specificity (73%) was obtained using the criterion that a lymph node contained cancer when at least three positive features were present. The present in vitro study demonstrated that the sensitivity and specificity of B-mode ultrasonography for diagnosing lymph node metastasis were lower than 90%. Therefore, B-mode ultrasonography may not be an optimal noninvasive screening method for diagnosing axillary lymph node metastasis in breast cancer patients, particularly under in vivo clinical conditions.

Adult↗
PubMed1999

[Study on CAF + medroxyprogesterone acetate (MPA) therapy for advanced or recurrent breast cancer--comparison between MPA 600 mg and 1,200 mg. Kyushu CAFT Therapy Study Group (Third Study)].

To find the optimal dose of MPA for combined use with CAF therapy for advanced or recurrent breast cancer, a randomized comparative study with a MPA 1,200 mg group and 600 mg group was carried out multi-institutionally. The response rate of complete cases was 37.5% (12/32) in the 1,200 mg group and 36.6% (15/41) in the 600 mg group, showing no difference between the two groups. There were no differences in either the duration of response or the survival term. The major adverse effects and abnormal laboratory test values included alopecia, nausea and vomiting, general fatigue, anorexia and leukopenia, with no difference in incidence between the groups. Moon face, genital hemorrhage and body weight increase, which are thought to be caused by MPA, were found in both groups without a significant difference in incidence. The results of this study revealed no differences in effectiveness or safety between MPA 1,200 mg and 600 mg, suggesting that MPA for combined use with CAF is fully effective at a dose of 600 mg.

Adult↗
PubMed1999

[Transanal endoscopic microsurgery (TEM)].

Minimally invasive surgery is mandatory for rectal tumors to reduce surgical complications and to improve the quality of life. The conventional transanal procedure is one from of minimally invasive surgery for rectal tumors, but it is still often difficult to reach the middle and upper thirds of the rectum due to anatomical characteristics. Transanal endoscopic microsurgery (TEM) is a technique that allows radical resection of rectal tumors in the distal as well as proximal third of the rectum. Performing radical surgery using this technique requires preoperative estimation of tumor extension both histologically and by X-ray images. It should allow provide safe and radical excision of rectal tumors. In our department, patients with rectal tumors are evaluated for risk factors using barium enema, endoscopic ultrasound, punch biopsy, etc. Fifty patients (rectal cancer, 34: cartinoid, 4: adenoma, 12) have undergone radical TEM. The operation was converted to open surgery in 2 cases because of rectal perforation. Radical open surgery was performed after TEM in 1 patient since cancer invasion was revealed by postoperatively upon histological examination. We conclude that TEM is a useful technique for radical resection of rectal tumors and is associated with a low rate of postoperative complications and a high surgical success rate.

Anal Canal↗
PubMed1998

Surgical treatment of lower rectal cancer with sphincter preservation using handsewn coloanal anastomosis.

The present study was designed to evaluate the technical feasibility and oncologic results of performing handsewn coloanal anastomosis (CAA). A total of 46 patients treated for lower rectal cancer using CAA were retrospectively studied, and the oncologic results were compared with those of 105 patients treated with abdominoperineal resection (APR). CAA was performed in patients who had both good mobility of the tumor and a distal clearance margin of more than 1.0 cm. No significant difference was noted in the mortality rates following the two operations (CAA 2.2% vs APR 1.9%). Pelvic recurrence was detected in two patients (4.5%) after CAA and in six patients (7.2%) after APR. The 5-year survival rate after CAA was 79.2% and that after APR was 72.6%. No significant difference was noted in the incidence of pelvic recurrence or the survival rates between the two operations. These results show that CAA could be an excellent reconstructive option in the treatment of lower rectal carcinoma for selected patients.

Adenocarcinoma↗
PubMed1998

Resection of malignant fibrous histiocytoma invading the thoracic aorta.

We report a case of surgically resected malignant fibrous histiocytoma which arose in the posterior mediastinum. Tumor removal with the required sufficient-margin and the resection of the affected thoracic aorta, led to flaccid paraplegia below the tenth thoracic level. This patient is now surviving with no evidence of recurrence at 42 months after the operation. Although malignant fibrous histiocytoma in the thorax generally shows a poor prognosis, this patient with complete resection could have a relatively long survival.

Aged↗
PubMed1998

Endobronchial metastasis from rectal adenocarcinoma: report of a case.

We herein report a case of late endobronchial metastasis after the resection of a primary rectal adenocarcinoma. A 51-year-old man underwent a resection of rectal adenocarcinoma. Five years postoperatively, he underwent a right sleeve upper lobectomy for a right endobronchial tumor. The resected tumor was diagnosed to be endobronchial metastasis from rectal adenocarcinoma. Therefore, the relationship between the two tumors was analyzed using deoxyribonucleic acid (DNA) flow cytometry and immunohistochemical staining. Endobronchial adenocarcinoma had strong homogeneous staining patterns and identical biochemical characteristics to rectal adenocarcinoma.

Adenocarcinoma↗
PubMed1998

In vitro investigation of lymph node metastasis of colorectal cancer using ultrasonic spectral parameters.

Lymph node involvement is one of the major factors affecting the prognosis of colorectal cancer. Various imaging methods, including ultrasound and computed tomography, are not sufficiently sensitive or specific for reliably determining lymph node involvement. We investigated the feasibility of using ultrasonic tissue characterization (UTC) based on spectrum analysis of backscattered echo signals for diagnosing lymph node metastasis of colorectal cancer in vitro. Forty lymph nodes, including 17 metastatic and 23 nonmetastatic nodes, from 11 colorectal cancer operations were investigated. Lymph nodes were scanned using a clinical instrument; B-mode imaging was performed for each lymph node, and radiofrequency (RF) data were acquired. The UTC parameters, slope and intercept, were calculated from the normalized power spectrum of the backscattered echo signals from each lymph node. The mean values of UTC parameters of metastatic and nonmetastatic lymph nodes were compared. The accuracy of UTC in distinguishing metastatic from nonmetastatic lymph nodes was calculated using discriminant analysis. Receiver operating characteristic (ROC) analysis was performed to compare the classification efficacy of UTC and B-mode ultrasound. UTC parameters demonstrated a significant difference in parameter values between metastatic and nonmetastatic lymph nodes. The overall accuracy in diagnosing the lymph node metastasis was 87.5% for UTC and 77.5% for B-mode ultrasound. ROC analysis produced an ROC curve area of 0.92 or 0.89 for UTC (depending on the performance-assessment algorithm) and 0.84 for B-mode ultrasound, which indicated that UTC performed markedly better than B-mode ultrasound in diagnosing metastatic lymph nodes. The advantages of UTC over conventional B-mode ultrasound in discriminating metastatic lymph nodes from nonmetastatic lymph nodes are extremely encouraging, and warrant an in vivo UTC study.

Aged↗
PubMed1998

In vitro diagnosis of axillary lymph node metastases in breast cancer by spectrum analysis of radio frequency echo signals.

Axillary lymph node status is of particular importance for staging and managing breast cancer. Currently, axillary lymph node dissection is performed routinely in cases of invasive breast cancer because of the lack of accurate noninvasive methods for diagnosing lymph node metastasis. We investigated the diagnostic ability of ultrasonic tissue characterization based on spectrum analysis of backscattered echo signals to detect axillary lymph node metastasis in breast cancer in vitro compared with in vitro B-mode imaging. Immediately after surgery, individual lymph nodes were isolated from axillary tissue. Each lymph node was scanned in a water bath using a 10-MHz instrument, and radio frequency data and B-mode images were acquired. Spectral parameter values were calculated, and discriminant analysis was performed to classify metastatic and nonmetastatic lymph nodes. Forty histologically characterized axillary lymph nodes were enrolled in this study, including 25 nonmetastatic and 15 metastatic lymph nodes. A significant difference existed in the spectral parameter values (slope and intercept) for metastatic and nonmetastatic lymph nodes. Spectral parameter-based discriminant function classification of metastatic vs. nonmetastatic lymph nodes provided a sensitivity of 93.3%, specificity of 92.0%, and overall accuracy of 92.5%. In comparison, B-mode ultrasound images of in vitro lymph nodes provided a sensitivity of 73.3%, specificity of 84.0%, and overall accuracy of 80.0%. Receiver operating characteristic (ROC) analysis comparing the efficacy of both methods gave an ROC curve area of 0.9888 for spectral methods, which was greater than the area of 0.8980 for B-mode ultrasound. Hence, this in vitro study suggests that the diagnostic ability of spectrum analysis may prove to be markedly superior to that of B-mode ultrasound in detecting axillary lymph node metastasis in breast cancer. Because of these encouraging results, we intend to conduct an investigation of the ability of spectral methods to classify metastatic axillary lymph nodes in vivo.

Adult↗
PubMed1998

Effects of glutamine supplements and radiochemotherapy on systemic immune and gut barrier function in patients with advanced esophageal cancer.

OBJECTIVE: The objective of this study was to determine whether oral glutamine supplements can protect lymphocyte and gut barrier function in patients with advanced esophageal cancer undergoing radiochemotherapy. SUMMARY BACKGROUND DATA: Glutamine supplements improved protein metabolism in tumor bearing rats who underwent chemotherapy and reduced the toxicity of chemotherapy through an enhancement of glutathione production in rats. METHODS: Thirteen patients with esophageal cancer were randomly placed in either a control or a glutamine group. Glutamine was administered orally (30 g/day) at the start of radiochemotherapy and for the subsequent 28 days. All patients underwent mediastinal irradiation and chemotherapy consisting of 5-fluorouracil and cisplatin. The lymphocyte count was determined, and blast formation was assessed after stimulation with phytohemagglutinin and concanavalin A. Gut barrier function was assessed by measuring the total amount of phenolsulfonphthalein excreted in the urine after the oral administration of phenolsulfonphthalein. RESULTS: Glutamine supplements prevented a reduction in the lymphocyte count (control: 567 +/- 96/mm3 vs. glutamine: 1007 +/- 151, p < 0.05), and blast formation of lymphocyte (phytohemagglutinin, control: 19478 +/- 2121 dpm vs. glutamine: 33860 +/- 1433, p < 0.01, concanavalin A, control: 19177 +/- 1897 dpm vs. glutamine: 29473 +/- 2302, p < 0.01), and amount of phenolsulfonphthalein excretion in the urine was greater with control than with glutamine group (control: 15.4 +/- 2.4% vs. glutamine: 7.4 +/- 1.2, p < 0.05) 7 days after the initiation of radiochemotherapy. CONCLUSIONS: Oral glutamine supplementation protects lymphocytes and attenuates gut permeability in patients with esophageal cancer during radiochemotherapy.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1998

Effect of fentanyl on morphine levels in the brain in rats receiving intracerebroventricular injection of TNF-alpha.

Fentanyl citrate analgesia attenuates the excess nitrogen excretion in the urine and glucose production induced by trauma. On the other hand, intracerebroventricular injection of morphine stimulates excretion of stress hormones, such as catecholamines and corticosterone. Furthermore, morphine levels in the brain are increased during fasting and sepsis. The aims of this study were to determine whether intracerebroventricular injection of tumor necrosis factor-alpha (TNF-alpha) elevates morphine levels in the rat brain and whether prophylactic administration of fentanyl blocks metabolic responses induced by intracerebroventricular injection of TNF-alpha because of a reduction of morphine levels in the brain. Morphine levels in the brain were increased from 648 to 1,134 fmol/g at 30 min after intracerebroventricular injection of TNF-alpha (P < 0.05 vs. control). This increase was associated with an increase in stress hormones (corticosterone: 416.1 +/- 69.1 ng/ml, P < 0.05 vs. control; epinephrine: 3,778.3 +/- 681.3 pg/ml, P < 0.01 vs. control) and an enhancement of proteolysis (254.2 +/- 45.7 micromol Leu . kg-1 . h-1, P < 0.01 vs. control) and glucose production (7.5 +/- 0. 7 mg . kg-1 . min-1, P < 0.05 vs. control). Fentanyl reduced morphine levels in the brain to 624 fmol/g (not significant vs. control), resulting in a reduction of stress hormone levels in the plasma and blunted metabolic responses. In conclusion, prophylactic administration of fentanyl prevented an increase in morphine levels in the brain induced by intracerebroventricular injection of TNF-alpha, leading to a reduction in stress hormone levels and subsequent metabolic responses.

Animals↗
PubMed1998

Experimental study of the histocompatibility of covered expandable metallic stents in the trachea.

STUDY OBJECTIVES: To evaluate the histocompatibility of four different materials used to cover expandable metallic stents. DESIGN: Prospective, randomized, unblinded study. SETTING: Animal research laboratory of Kurume University. PATIENTS OR PARTICIPANTS: Twenty 12- to 18-kg mongrel dogs. INTERVENTIONS: Handmade Gianturco-type stents with six bends, 20 mm in length, and 15 to 20 mm in diameter were covered using four different materials: polypropylene mesh, silicone-coated mesh, polyester mesh, and ePTFE. Covered stents were inserted into the trachea after i.v. anesthesia. Five animals were used in each group. MEASUREMENTS AND RESULTS: Postinsertion status was observed using clinical and bronchoscopy measures 7, 14, 28, and 56 days after intervention. Eight weeks after stent insertion, the tracheal specimens were studied pathologically. A scoring system was used to evaluate the histocompatibility of covered stents in each study group. The mean of clinical scores in the polypropylene group was 1.84+/-0.36, which was significantly higher than those in the groups of silicone, polyester, and ePTFE. The means of histopathologic scores in the polypropylene group and the silicone group were 1.60+/-0.55, which were significantly higher than those in groups of polyester and ePTFE. CONCLUSIONS: Polypropylene mesh cover was more suitable than silicone-coated mesh, polyester mesh, and ePTFE because of its excellent histocompatibility.

Anesthesia, Intravenous↗
PubMed1998

Metastatic model of human colon cancer constructed using orthotopic implantation in nude mice.

Nude mice have been used to grow subcutis (s.c.) growing human colorectal tumors, but these tumors rarely metastasize. This is a problem for studies into the biological behavior of metastatic subpopulations of human colorectal cancers. We have followed the evolution of the parental line and of a variant of human colon carcinoma KM12 cells, that were both tumorigenic, following implantation into the s.c. or cecal wall of nude mice. The tumors growing s.c. did not produce visceral metastases, whereas the cecal tumors metastasized to the regional mesenteric lymph nodes and to the liver. However, the incidence of liver metastases was different between the parental cell line KM12C cells and the in vivo selected cell line KM12SM cells after orthotopic inoculation. The morphological findings of KM12 cells proliferating in a monolayered sheet revealed that these two cell lines consisted of various cell populations. These results suggest that in the orthotopic colon cancer models, liver metastasis is defined by difference in subpopulations of metastatic phenotypes to the liver with early dominance of its growth in the implanted organ. As a result, our new model using orthotopic implantation of KM12SM cells, which produce a 50% incidence of liver metastasis, can help to provide a technique to study the biological behavior of metastatic subpopulations of human colon cancers.

Animals↗
PubMed1998

Clinical aspects of total colectomy--laparoscopic versus open technique for familial adenomatous polyposis and ulcerative colitis.

Clinical aspects of laparoscopy combined total colectomy (LTC) (n = 10) and open total colectomy (OTC) (n = 29) with ileorectal anastomosis for familial adenomatous polyposis and ulcerative colitis are compared in a retrospective study. The mean operative time was 282 (range, 169 to 420) minutes in the LTC group and 274 (range, 139 to 570) minutes in the OTC group. The mean volume of operative blood loss was 321 (range, 52 to 728) ml and 471 (range, 48 to 1040) ml for the LTC and OTC groups, respectively. Nasogastoric tube could be removed after POD 1.2 vs. 5.8 (p < 0.05), the mean time to passage of stool was 1.9 (range, 1 to 3) vs. 5.2 (range, 3 to 7) days (p < 0.01), and in the LTC group watery stool was soon made solidification after POD 23.4 vs. 84.1 (p < 0.01). Laparoscopy combined total colectomy may prove to have one-stage restorative total colectomy without a temporary ileostomy due to early solidification of watery stool and more benefits than conventional open surgery.

Adenomatous Polyposis Coli↗