Biomedical subjects

Yutaka Atomi

Publications and source records attributed to Yutaka Atomi.

At least 73 records · Page 4Linked to original sources

PubMed2002

Preoperative staging by multidetector-row computed tomography in patients with rectal carcinoma.

BACKGROUND: Multidetector-row computed tomography (MDCT, or multi-slice CT) has been introduced in 2000. So far, there has been no published study on this modality in patients with rectal carcinoma. METHODS: Twenty patients with rectal carcinoma were preoperatively examined by MDCT and conventional CT (CCT). Diagnostic accuracies of both modalities were compared regarding the evaluation of depth of tumor invasion (Tis/T1/T2, T3, T4) and lymph node metastasis based on the pathologic findings. RESULTS: Although CCT detected a tumor in 13 (65%) of 20 patients, MDCT revealed a tumor in all 20 patients (P = 0.004). Regarding depth of tumor invasion, the concordance rate was significantly higher for MDCT (20/20: 100%) than for CCT (12 of 20: 60%; P = 0.002). Regarding lymph node metastasis, the overall accuracy was 70.0% in CCT, and also 70.0% in MDCT. CONCLUSIONS: MDCT was superior to CCT in the evaluation of depth of tumor invasion, but was equal to CCT in the evaluation of lymph node metastasis.

Adenocarcinoma↗

PubMed2002

Differential diagnosis of benign versus malignant nonfunctioning islet cell tumors of the pancreas: the roles of EUS and ERCP.

BACKGROUND: Differentiation between benign and malignant nonfunctioning islet cell tumors of the pancreas before surgery is often difficult. The roles of EUS and ERCP were evaluated in the differential diagnosis of these tumors. METHODS: Seven patients with histologically confirmed nonfunctioning islet cell tumors (4 benign, 3 malignant) underwent EUS and ERCP. OBSERVATIONS: EUS demonstrated a homogeneous hypoechoic mass or a hypoechoic mass with a regular central echogenic area in the 4 cases of benign tumor, and a hypoechoic mass with an irregular central echogenic area in all 3 cases of malignant tumor. The irregular central echogenic area corresponded to severe hemorrhage, necrosis, or fibrosis with hyalinosis (hyaline degeneration) on pathologic examination. ERCP demonstrated displacement or complete obstruction (because of ductal invasion) of the main pancreatic duct in 2 patients with malignant tumors and no abnormalities in the other 5 cases. CONCLUSIONS: In patients with nonfunctioning islet cell tumors, a hypoechoic mass with an irregular central echogenic area on EUS or complete obstruction of the main pancreatic duct on ERCP suggests malignancy.

Adenoma, Islet Cell↗

PubMed2002

Pancreatic endocrine function and glucose transporter (GLUT)-2 expression in rat acute pancreatitis.

INTRODUCTION: Impairment in pancreatic endocrine function is believed to play an important role in the development of glucose intolerance in acute pancreatitis. AIM: To investigate the functional aspects of endocrine cells in acute pancreatitis and the expression of glucose transporter (GLUT) 2 in the pancreatitis islet. METHODOLOGY: A mild form of acute pancreatitis was induced in rats by an injection of a sodium taurocholate solution via a cannulated biliopancreatic duct. Isolated islets were stimulated by glucose, and insulin secretion was analyzed by radioimmunoassay. Immunohistochemical detection of GLUT2 with use of a specific antibody was attempted to determine GLUT2 expression in pancreatic islets. RESULTS: A marked elevation of glucose levels observed in the current rat pancreatitis model confirmed that glucose intolerance can occur even in a mild form of pancreatitis. The architecture of the islets, however, remained intact despite marked inflammatory changes in the neighboring exocrine region. Insulin secretion studies revealed that the ability of islets to secrete insulin in response to glucose was markedly reduced in pancreatitis islets. GLUT2 immunoreactivity in endocrine cells was found to be intact in pancreatitis islets. CONCLUSION: The amount of insulin released from isolated islets following glucose stimulation is reduced in acute edematous pancreatitis, although pancreatic islets remain histologically intact. On the basis of the present findings, it appears that although the mechanisms responsible for this functional deficiency remain to be determined, the decrease in insulin secretion is possibly caused by impairment of some pancreatic B-cell functions rather than GLUT2-mediated glucose transportation.

Acute Disease↗

PubMed2002

Diagnostic significance of high mobility group I(Y) protein expression in intraductal papillary mucinous tumors of the pancreas.

INTRODUCTION: Overexpression of the high mobility group I(Y), [HMGI(Y)], gene/proteins has been demonstrated in many types of human malignancies, suggesting that HMGI(Y) may play a vital role in the oncogenic transformation of cells. AIMS: To analyze HMGI(Y) expression in intraductal papillary mucinous tumor (IPMT) of the pancreas to verify whether determination of the HMGI(Y) expression level could provide any diagnostic advantages in the pathological diagnosis of IPMT. METHODOLOGY: Thirty-three different lesions from 25 patients with IPMT, including 20 with mild dysplasia, 7 with moderate dysplasia, and 6 with carcinoma, were analyzed immunohistochemically with use of an HMGI(Y)-specific antibody. RESULTS: Immunohistochemical analysis revealed that, although no significant immunoreactivity was found in cases of normal pancreatic duct or mild dysplasia, 28.6% (2/7) of moderate dysplasia showed multifocal immunoreactivity with moderate intensity. In contrast, in 50% (3/6) of the cases of carcinoma, intense multifocal or diffuse immunoreactivity occurred, almost equivalent to that observed in cases of duct cell carcinoma, whereas in the remaining 3 cases of carcinoma only a faint focal immunoreactivity occurred. Histologic examination revealed that these HMGI(Y)-positive carcinomas had an invasive growth pattern, whereas the HMGI(Y)-negative carcinomas were either carcinomas in situ or tumors with minimal invasion. Thus, an increased expression level of HMGI(Y) proteins was closely associated with the malignant phenotype in IPMT. CONCLUSION: On the basis of these findings, we propose that HMGI(Y) proteins could play an important role(s) in a multistage process of carcinogenesis of IPMT and that the HMGI(Y) protein level could serve as a potential diagnostic marker, which may enable the identification of tumor cells with potential to be biologically malignant.

Adenocarcinoma, Mucinous↗

PubMed2002

Development and use of a new staging system for severe acute pancreatitis based on a nationwide survey in Japan.

METHODOLOGY: In 1997, a cooperative nationwide survey of 192 patients diagnosed with severe acute pancreatitis in 1996 was carried out. RESULTS: Alcoholic pancreatitis was the major etiology (46%), and the male-to-female ratio was 2.6:1. Overall, the mortality rate was 27%, which was similar to the rate (30%) in the first nationwide survey of 1,219 patients diagnosed between 1982 and 1986 that was performed in 1987. A marked difference between the surveys was the early mortality rate within 2 weeks: 52% in the 1987 survey and 29% in the current survey. We devised a new stage classification system for acute pancreatitis. Stages 0 and 1 are equivalent to mild and moderate conditions, respectively, in the conventional classification, and stages 2 and higher correspond to severe acute pancreatitis. Severity scores of 2-8 are regarded as stage 2, scores of 9-14, as stage 3, and scores of > or =15, as stage 4. The mortality rates were as follows: 0, stages 0 and 1 at hospitalization; approximately 10%, stage 2; approximately 30-40%, stage 3; and approximately 70-100%, stage 4. CONCLUSION: We found that stage at hospitalization reflected the prognosis of acute pancreatitis.

Acute Disease↗

PubMed2002

Risk factors predictive of late complications after endoscopic sphincterotomy for bile duct stones: long-term (more than 10 years) follow-up study.

OBJECTIVE: Widespread use of laparoscopic cholecystectomy has extended the indications for endoscopic sphincterotomy (ES) to young patients with choledocholithiasis; however, long-term results of ES and risk factors for late complications are largely unknown. METHODS: Between 1977 and 1990, 145 patients aged 60 yr or younger underwent ES for choledocholithiasis. Long-term outcomes of ES were investigated in the year 2000, and prognostic factors for late complications were multivariately analyzed. RESULTS: Long-term information was available in 135 cases (93.1%), with a median overall follow-up duration of 14.5 yr (range, 6.5-22.3 yr). There were neither biliary malignancies nor deaths attributable to biliary disease. Sixteen patients (11.9%) developed late complications, including choledochal complications (stone recurrence and/or cholangitis; 14 patients) and acute cholecystitis (two of 32 patients with the gallbladder in situ). Multivariate analysis identified two independent risk factors for choledochal complications: bile duct diameter > or = 15 mm and brown pigment stones at the initial ES. Choledochal complications were endoscopically manageable. All recurrent stones were brown pigment stones. CONCLUSIONS: Approximately 12% of patients develop late complications after ES, but retreatment with ERCP is effective. ES is a reasonable alternative even in young patients with choledocholithiasis. Careful follow-up is necessary, however, particularly for patients with a dilated bile duct or brown pigment stones.

Adult↗

PubMed2001

In Vivo Effect of Pancreatic Phospholipase A2 on the Arachidonic Acid Cascade.

Acute pancreatitis causes various systemic complicationssuch as shock, renal failure, respiratory failure, disseminated intravascular coagulation, and eventually,multiple organ dysfunction syndrome. These systemic complications are responsible for the highmortality rates of acute pancreatitis. Thus, an understandingof their pathogenesis is imperative to reducethe mortality of acute pancreatitis.

Journal Article↗

PubMed2001

Cavernous Pancreatic Ductal Ectasia with Smooth Muscle Proliferation Causing Recurrent Acute Pancreatitis.

Pancreatic cystic lesions have various etiologies,including pseudocyst (inflammatory cyst), retentioncyst, congenital cyst, and neoplastic cyst (1).Recently, we experienced a case with a uniquepancreatic cyst-like lesion causing recurrent acutepancreatitis. This patient had multiple cystic dilatations of branch pancreatic ducts surrounded by proliferationof smooth muscle tissue, with neither neoplastic nor inflammatory changes. To our knowledge, there are no previous reports of such a case.

Journal Article↗

PubMedDate not supplied

Long-term effects of endoscopic papillary balloon dilation on gallbladder motility.

We prospectively studied long-term (5 years) effects of endoscopic papillary balloon dilation (EPBD) on gallbladder motility. Thirteen patients with intact gallbladders (six with and seven without gallbladder stones) who had undergone EPBD for choledocholithiasis were enrolled in this study. Gallbladder volumes, while fasting and after dried egg yolk ingestion, were determined by ultrasonography, before and at 7 days, 1 month, and 1, 2, and 5 years after EPBD. Before EPBD, the gallbladder had a larger fasting volume and lower yolk-stimulated maximum contraction than in normal controls. Seven days after EPBD, fasting volume was decreased and maximum contraction was increased, regardless of whether the patient had gallbladder stones, showing significant differences from the pre-EPBD values. At 1 month to 5 years after EPBD, these changes were far less evident and gallbladder function did not differ significantly from baseline. EPBD does not adversely affect gallbladder motility in the long-term (5 years).

Aged↗

PubMedDate not supplied

Budding as a useful determinant of the optimal treatment for T1 rectal carcinomas.

BACKGROUND/AIMS: If a locally excised specimen has poorly differentiated or undifferentiated histology, positive vascular invasion, or massive invasion to the cut end or a positive margin, additional surgery is recommended for the treatment of T1 rectal carcinoma. However, positive predictive values of these histological criteria are low. This study was undertaken to clarify more reliable risk factor(s) for lymph node metastasis in T1 rectal carcinomas. METHODOLOGY: In 58 patients with T1 rectal carcinoma undergoing local excision or radical surgery, the associations between lymph node metastasis or intrapelvic recurrence and clinicopathological features were studied using multiple regression analysis with special reference to tumor budding at the invasive front. RESULTS: Lymph node metastasis was observed in 1 of 9 patients undergoing additional bowel resection after local excision, and in 2 of 24 patients undergoing radical surgery alone. Intrapelvic extrarectal recurrence was observed in 3 of 25 patients undergoing local excision alone. Logistic regression analysis revealed that budding at the invasive front alone was significantly associated with lymph node metastasis or intrapelvic recurrence (p = 0.0484). CONCLUSIONS: Additional bowel resection with lymph node dissection should be recommended for locally excised T1 rectal carcinoma with budding at the invasive front.

Adult↗

PubMedDate not supplied

Carcinoembryonic antigen levels in peritoneal washes: a potential prognostic marker for patients with colorectal cancer.

BACKGROUND/AIMS: This study was conducted to define the clinical significance of intraoperative determination of carcinoembryonic antigen levels in peritoneal washes from patients undergoing surgery for colorectal cancer. METHODOLOGY: The correlation of carcinoembryonic antigen levels in peritoneal washes (pCEA) with several clinicopathological factors and the long-term surgical outcome in 54 patients with resectable colorectal cancer was determined retrospectively. RESULTS: Among several clinicopathological factors, the depth of tumor invasion significantly and independently correlated with pCEA levels as revealed by multivariate stepwise logistic regression analysis. A significant difference in overall survival rates was observed between pCEA-positive and pCEA-negative groups: five-year survival rates were 97.1% in pCEA-negative patients and 78.9% in pCEA-positive patients (p = 0.0274). CONCLUSIONS: Intraoperative determination of carcinoembryonic antigen levels in peritoneal washes could be a potentially predictive factor of a poor prognosis in patients with colorectal cancer.

Adult↗

PubMedDate not supplied

Laminin-5 gamma 2 chain and matrix metalloproteinase-2 may trigger colorectal carcinoma invasiveness through formation of budding tumor cells.

UNLABELLED: Tumor budding has been reported to be significantly associated with lymph node or distant metastasis in colorectal carcinomas. We attempted to elucidate the contributing factors for the formation of budding tumor cells. PATIENTS AND METHODS: Fifty T1 colorectal carcinomas were immunostained using several antibodies against adhesion-related molecules, and the associations between tumor budding and clinicopathological factors were examined. RESULTS: Univariate analysis revealed that predominant histology, lymphatic permeation, depth of invasion, width of invasion, CD44 variant 6 expression, laminin-5 gamma 2 chain expression and stromal MMP-2 expression were associated with tumor budding. Multivariate analysis showed that lymphatic permeation, laminin-5 gamma 2 chain expression and stromal MMP-2 expression were independently and significantly associated with tumor budding. Furthermore, laminin-5 gamma 2 chain and stromal MMP-2 expression patterns were significantly associated with locoregional failure. CONCLUSION: These results suggest that laminin-5 gamma 2 chain and MMP-2 may contribute synergistically to the formation of budding tumor cells.

Aged↗

PubMedDate not supplied

Matrix metalloproteinases may contribute compensationally to tumor invasion in T1 colorectal carcinomas.

BACKGROUND: Few investigators have focused on possible interactions among several MMPs collectively. MATERIALS AND METHODS: Immunostaining for MMP-7, MMP-2 and MT1-MMP was performed on 51 early invasive (T1) colorectal carcinomas, and correlations between the expressions of pairs of MMPs were examined. RESULTS: MMP-7 expression was positive at the invasive front in 18 (35%) out of 51 tumors. Cytoplasmic MMP-2 expression was positive in 20(39%) out of 51 tumors, whereas its expression in the stroma was positive in 17(33%) out of 51 tumors. MT1-MMP was localized predominantly in the tumor cell cytoplasm in 14 (27%) out of 51 tumors. There was an inverse correlation between MMP-7 and cytoplasmic MMP-2 expression with marginal significance (p = 0.06), and between MMP-7 and MT1-MMP expression with statistical significance (p = 0.01). The association between cytoplasmic MMP-2 and MT1-MMP expression was statistically significant (p = 0.0004). CONCLUSION: MMP-7 and MMP-2 or MT1-MMP may contribute compensationally to tumor invasion and metastasis in T1 colorectal carcinomas.

Colorectal Neoplasms↗

PubMedDate not supplied

Risk factors for acute pancreatitis after endoscopic papillary balloon dilation.

BACKGROUND/AIMS: Although EPBD (endoscopic papillary balloon dilation) may cause acute pancreatitis, risk factors for post-EPBD pancreatitis have not been well described. We retrospectively analyzed risk factors predictive of acute pancreatitis after EPBD. METHODOLOGY: A total of 101 patients underwent EPBD for choledocholithiasis. Post-EPBD acute pancreatitis was investigated. Nineteen potential risk factors, related to clinical characteristics or procedures, were retrospectively analyzed univariately and multivariately. RESULTS: Bile duct clearance was achieved in 96 patients. Serum amylase was elevated after EPBD in 69 patients. Early complications occurred in 11 patients (11%); 5 had minimal (pain persisting for only 12-24 hours) and 6 mild (requiring 1-3 days of treatment) pancreatitis. These 11 patients showed at least a three-fold elevation of serum amylase. Multivariate analysis identified two independent risk factors for pancreatitis (prior history of acute pancreatitis, and bile duct diameter < or = 9 mm). The risk for post-EPBD pancreatitis was not associated with young age, pre-EPBD hyperamylasemia, large or multiple stones, periampullary diverticulum, pancreatic contrast injection, mechanical lithotripsy or residual stones. CONCLUSIONS: Acute pancreatitis, usually mild or minimal, can be anticipated after EPBD for bile duct stones in approximately 10% of patients. In those with previous pancreatitis or a non-dilated bile duct, special care is necessary given the high incidence of pancreatitis.

Acute Disease↗

PubMedDate not supplied

Gadolinium enhanced endorectal coil and air enema magnetic resonance imaging as a useful tool in the preoperative examination of patients with rectal carcinoma.

BACKGROUND/AIMS: In the present study, we attempted to evaluate the usefulness of gadolinium enhanced endorectal coil and air enema magnetic resonance imaging with slice adjustments in patients with rectal carcinoma. METHODOLOGY: The subjects were patients with rectal cancer from June 1997 to September 1999 who were examined with a 1.5 Tesla magnetic resonance device. Buscopan was administered both intravenously and intramuscularly to reduce motion artifacts. Imaging sequences were obtained for T1 weighed, T2 weighed and T2 fat-saturated images. Slice thickness was 5 mm and interslice gap 3 mm. Endorectal coil insertion and air enema technique were performed with slice adjustments. Images were interpreted according to the criteria of the TNM classification. Lymph node metastasis was diagnosed as positive when the lymph nodes exceeded 5 mm in diameter. Histological and magnetic resonance findings were compared, and diagnostic accuracy was calculated. RESULTS: Fifty-four consecutive patients were included in this study (37 male, 17 female). There were 10 early cases and 44 advanced cases of rectal cancer. Images with an endorectal coil were obtained in 4 patients. Fifty patients underwent air enema technique. The depth of tumor invasion was accurately diagnosed in all 4 patients undergoing endorectal coil examination. On air enema study, magnetic resonance imaging correctly staged the depth of invasion in 41 of 50 patients (82.0%). Overstaging was seen in 8 of 50 patients (16%), however, only one patient (2.0%) was understaged. Overall accuracy, overstaging and understaging rates were 83.3% (45/54), 14.8% (8/54), and 1.8% (1/54), respectively. On endorectal coil study, accurate diagnosis of lymph node metastasis was obtained in 3 of 4 (75.0%) patients. On air enema study, an accurate diagnosis of lymph node metastasis was obtained in 36 of 50 (72.0%) patients, yielding 75.0% sensitivity and 73.1% specificity. Overall magnetic resonance imaging findings of lymph node metastasis resulted in 72.2% (39/54) diagnostic accuracy, yielding sensitivity of 75.0% (18/24) and specificity of 73.3% (22/30). CONCLUSIONS: We conclude that gadolinium enhanced endorectal coil and air enema magnetic resonance imaging is promising for preoperative evaluation of patients with rectal carcinoma.

Air↗

PubMedDate not supplied

Laparoscopy-assisted surgery for colorectal neoplasm is justifiable regardless of advanced age.

BACKGROUND/AIMS: Laparoscopy-assisted surgery has been applied in patients with colorectal disease and resulted in favorable outcome compared with open surgery. However, it is not reported exclusively in terms of the curative mean in the geriatric patients with colorectal neoplasm yet. The aim of this study was to confirm the pros and cons of laparoscopy-assisted surgery for colorectal neoplasm in geriatric patients. METHODOLOGY: Seventy-four patients with colorectal neoplasm underwent laparoscopic surgery and all their charts were retrospectively reviewed. Fourteen patients were 75 years of age or older and compared with the remaining non-aged 60 patients in STUDY 1, and also compared with 46 aged patients who underwent open surgery in STUDY 2. RESULTS: In STUDY 1, the compiled total frequency of preoperative concomitant disease was significantly higher in the LAS-aged group. In STUDY 2, the mean operative time of the laparoscopic group was significantly longer than that of the open group. Mean estimated blood loss of the laparoscopic group was significantly smaller than that in the open group. Postoperative oral resumption and duration of hospital stay tended to be shorter in the laparoscopic group than in the open group. CONCLUSIONS: Laparoscopy-assisted surgery is a satisfactory treatment for colorectal neoplasm, even in geriatric patients.

Aged↗

PubMedDate not supplied

MRI diagnosis of mesorectal lymph node metastasis in patients with rectal carcinoma. what is the optimal criterion?

BACKGROUND: Preoperative diagnosis of lymph node metastasis is often difficult. A number of different criteria have been advocated in the literature, however, an optimal criterion has not yet been determined in patients with rectal carcinoma. PATIENTS AND METHODS: Fifty-one patients, undergoing radical surgery with total mesorectal excision, were examined with reference to regional lymph node status. MRI and pathological findings were compared, and an optimal preoperative criterion was clarified by receiver operating characteristic (ROC) analysis. RESULTS: Among size, shape and internal structure criteria, size was a significant factor for diagnosing metastatic lymph node on MRI. ROC analysis showed that a criterion of 6-mm or larger in the longitudinal axis was the most reliable in differentiating metastatic and non-metastatic lymph nodes, with overall accuracy of 78%. CONCLUSION: A 6-mm longitudinal diameter criterion is thought to be most optimal in the evaluation of mesorectal lymph node status in patients with rectal carcinoma.

Female↗

PubMedDate not supplied

En bloc endoscopic mucosal resection of a large early stage gastric cancer by combined use of an insulation-tipped diathermic knife and a grasping forceps percutaneously inserted into the gastric lumen.

A new endoscopic mucosal resection using an insulation-tipped diathermic knife (IT knife-EMR) is a promising procedure for en bloc resection of an early stage gastric cancer. However, the use of this procedure for a large lesion on the greater curvature of the gastric middle-upper body is technically difficult. With the help of a grasping forceps percutaneously inserted into the gastric lumen, which allowed traction to be applied to the lesion, a 66-year-old man with a large tumor (49mm in diameter) on the greater curvature of the gastric middle body underwent IT knife-EMR. This approach enabled easy dissection between the submucosa and the muscle layer by the IT knife under direct vision. The lesion was completely removed as a single piece. This new technique, employing IT knife-EMR in cooperation with a percutaneously inserted grasping forceps, could be a potential procedure to make original IT knife-EMR easier. This approach may enhance the utility of original IT knife-EMR for selected tumors, that is, large tumors on the greater curvature of the middle-upper body of the stomach and/or ulcerated tumors. We propose that the present approach may provide an important alternative to laparoscopic intragastric surgery.

Adenocarcinoma↗