Search PubMed⌕ Search

Biomedical subjects

Wataru Kimura

Publications and source records attributed to Wataru Kimura.

At least 19 recordsLinked to original sources
PubMed2006

Effect of a selective thromboxane A2 synthetase inhibitor on the systemic changes induced by circulating pancreatic phospholipase A2.

BACKGROUND: In acute pancreatitis, pancreatic phospholipase A(2) (PLA2) in the circulating blood hydrolyzes phospholipids contained in plasma lipoproteins, liberating eicosanoid precursors that are subsequently converted to various eicosanoids. The pathophysiological significance of eicosanoid synthesis via this pathway is unknown. The aim of this study was to clarify the role of thromboxane A(2) (TXA(2)) synthesis by circulating pancreatic PLA(2) in the pathogenesis of the systemic complications of acute pancreatitis. METHODS: Guinea pigs were divided into two groups: a control group and an ozagrel group, which received intravenous administration of ozagrel, a selective TXA(2) synthetase inhibitor. Pancreatic PLA(2) was infused intravenously in both groups for 30 min, and systemic changes during the infusion were examined. RESULTS: In the control group, there was an increase in plasma thromboxane B(2) (TXB(2)) concentration, a decrease in mean arterial pressure and heart rate, a decrease in arterial base excess (BE), bicarbonate concentration (HCO(3) (-)), and pH, a decrease in platelet count and plasma fibrinogen concentration, and a shortened prothrombin time during the infusion of pancreatic PLA(2). In the ozagrel-treated group, changes in plasma TXB(2) concentration, BE, HCO(3) (-), and platelet count were significantly inhibited. CONCLUSIONS: TXA(2) synthesis by circulating pancreatic PLA(2) contributes to metabolic acidosis and thrombocytopenia during acute pancreatitis.

Acute Disease↗
PubMed2006

Nodal involvement as an indicator of postoperative liver metastasis in carcinoma of the papilla of Vater.

BACKGROUND/PURPOSE: Although lymph node metastatic involvement is one of the most important prognostic factors for carcinoma of the papilla of Vater, a detailed analysis of this factor in relation to prognosis has not been conducted. METHODS: From 1985 to 2003, 29 patients with carcinoma of the papilla of Vater underwent pancreaticoduodenectomy and dissection of regional lymph nodes at Yamagata University Hospital. We analyzed clinicopathologic variables in relation to prognosis and precisely evaluated nodal involvement in each patient to determine lymphatic flow. Furthermore, the relationship between recurrent site and nodal involvement was investigated. RESULTS: The overall survival rate was 55% at 5 years. The significant prognostic factors were morphological ulcer formation (P = 0.04), histological type (P = 0.03), nodal involvement (P = 0.002), and lymphatic invasion (P = 0.03). Multivariate analysis indicated no independent factor, but nodal involvement may be the strongest prognostic factor. The overall rate of nodal involvement was 41.4% (12 of 29 patients). The metastatic rates in the superior posterior pancreaticoduodenal lymph nodes, the inferior posterior pancreaticoduodenal lymph nodes, the superior mesenteric lymph nodes, and paraaortic lymph nodes were high (31.0%, 20.7%, 17.2%, and 13.8%, respectively). Patients with nodal involvement had a significantly higher rate of liver metastasis after surgery than those without it (P = 0.02). Ulcer formation and histological type were significantly correlated with nodal involvement (P = 0.05 and P = 0.002, respectively). CONCLUSIONS: Nodal involvement is the most important prognostic factor in patients with carcinoma of the papilla of Vater. Patients with nodal involvement are at high risk of liver metastasis; therefore, adjuvant therapy may be necessary for the control of liver metastasis. Preoperative ulcer formation and histological type in the biopsy specimen are good indicators for extended lymph node dissection and adjuvant therapy, because these variables are correlated with nodal involvement. However, our data revealed only the sites of the positive nodes, without addressing the effect of extended lymph node dissection and adjuvant chemotherapy. To date, there has been reporting of extended lymph node dissection and adjuvant chemotherapy in patients with carcinoma of the papilla of Vater. Further studies will be necessary to resolve these problems.

Adult↗
PubMed2006

Anatomy of right recurrent nerve node: why does early metastasis of esophageal cancer occur in it?

Early, distant and/or skip metastasis of squamous-cell thoracic esophageal cancer frequently occurs in the right recurrent nerve node (recR). However, the specific lymphatic route without a nodal relay, such as the submucosal ascending route, was not known for the recR afferent. Using 20 donated cadavers, macroscopic, and histological observations were performed on the recR and its surrounding lymphatics, especially afferent routes from the esophagus to the recR. Most afferent vessels of the recR originated from the right paratracheal node. However, the recR often (12/20) received a major submucosal lymphatic drainage route ascending along the thoracic esophagus. The submucosal vessel came out of the esophagus and ran in a longitudinal connective tissue mass along the right tracheo-esophageal groove. A direct drainage route was often (13/20) seen from the recR to the venous system. Moreover, because of the specific histology, collaterals seemed to be present around the recR. In the regional nodes of the intrathoracic esophagus, the recR histology was characterized by the high proportion of lymphocyte accumulating areas or the cortex. From the midthoracic level, metastatic cancer cells seemed to reach the recR via esophageal submucosal vessels in the early stage. Large lymphocyte accumulating areas of the recR suggested higher filtration capacity than other distal nodes. However, the collateral of the recR and its direct drainage to the venous system suggested that the recR involvement often corresponds to a systemic disease.

Afferent Pathways↗
PubMed2006

An unusual case of undifferentiated carcinoma in situ with osteoclast-like giant cells of the pancreas.

OBJECTIVES: We report an unusual case of undifferentiated carcinoma in situ with osteoclast-like giant cells (UC with OGCs) in a 68-year-old Japanese woman. METHODS: Preoperative examinations revealed an unidentifiable mass lesion within the main pancreatic duct (MPD) in the pancreatic head, accompanied by a dilated MPD distal to the mass lesion, which was suspected to be an intraductal papillary-mucinous neoplasm of the main-duct type with acute pancreatitis because of an increased serum amylase level. A pancreaticoduodenectomy was performed. RESULTS: A pencil-like tumor occupied the lumen of the MPD of the pancreatic head without a visible pancreatic parenchymal mass. The intraductal tumor included a sheet of spindle cells intermingled with scattered OGCs and pleomorphic giant cells. A poorly developed glandular pattern was occasionally observed at the tumor periphery. These findings were consistent with conventional UC with OGCs. However, extraductal invasion was not found in an extensive histopathologic examination, although focal intraductal spreading into the epithelium of the first branch of the MPD was observed. CONCLUSIONS: Undifferentiated carcinoma with OGCs usually exhibits an invasive tumor at diagnosis and is associated with a poor outcome, but the patient is alive without recurrence 22 months after surgery. To our knowledge, this is the first reported case of UC in situ without evident extraductal invasion in English literature.

Aged↗
PubMed2006

[Participation of the clinical laboratory in the nutrition support team].

Recently, organization of the nutrition support team (NST) is progressing steadily in many hospitals in Japan. In our Yamagata University Hospital, NST services were started in March, 2004. As is well known, NST is a multidisciplinary team comprised of physicians, nurses, dietitians, pharmacists, social workers and medical technologists. Here, we report the participation of medical technologists and physicians belonging to our Clinical laboratory in NST activities. From our laboratory, two medical technologists and two physicians participate in the NST and provide the following services. Firstly, nutritional assessment of proteins in serum i.e. albumin, retinol binding protein (RBP) and transthyretin (TTR) is carried out, measured as part of routine work, and, especially, the data of RBP and TTR are applied to the assessment of nutrition status around the digestive surgical operations. They are also useful to assess the effect of dietary meal, immunonutrition "Impact", which improves the malnutrition status of the pre operative patient. Secondly, a weekly "malnutrition report", including numbers of patients with malnutrition in every ward, serial graphs, and detailed comments on their movements, is reported by e-mail to NST associated departments. This report is conveniently indicates the nutritional situation of inpatients in the hospital and aids consideration of countermeasures for malnutrition in the NST meeting. Thirdly, we medical technologists also participate in making rounds, where we state our opinions on a patient's data, and, if necessary, propose to the chief physician to request additional laboratory tests. We believe that these current activities of our laboratory as part of the NST will contribute to the development of our University NST, raising the quality of nutrition support services, and resulting in improvements of malnutrition and the quality of life of patients.

Medical Laboratory Science↗
PubMed2005

Fate and plasticity of the endoderm in the early chick embryo.

In vertebrates, the endoderm is established during gastrulation and gradually becomes regionalized into domains destined for different organs. Here, we present precise fate maps of the gastrulation stage chick endoderm, using a method designed to label cells specifically in the lower layer. We show that the first population of endodermal cells to enter the lower layer contributes only to the midgut and hindgut; the next cells to ingress contribute to the dorsal foregut and followed finally by the presumptive ventral foregut endoderm. Grafting experiments show that some migrating endodermal cells, including the presumptive ventral foregut, ingress from Hensen's node, not directly into the lower layer but rather after migrating some distance within the middle layer. Cell transplantation reveals that cells in the middle layer are already committed to mesoderm or endoderm, whereas cells in the primitive streak are plastic. Based on these results, we present a revised fate map of the locations and movements of prospective definitive endoderm cells during gastrulation.

Animals↗
PubMed2005

Expression patterns of the chicken peroxisome proliferator-activated receptors (PPARs) during the development of the digestive organs.

Peroxisome proliferator-activated receptors (PPARs) play very important roles in various biological phenomena such as regulation of lipid metabolism, homeostasis, cell differentiation and proliferation, in a variety of organs and tissues. However, their functions in the development of the digestive organs have not been studied yet, although it has been supposed that they are involved in the tumor development and regression of digestive organs. To provide fundamental data to analyze functions of PPARs in the developing digestive organs in the chicken embryos, we performed thorough analysis of expression of PPARalpha, beta (delta) and gamma in the esophagus, proventriculus (glandular stomach), gizzard (muscular stomach), small and large intestines from early developmental stages to post hatch stages. The results showed that each PPAR is expressed in spatio-temporally regulated manner. In general, PPARbeta is widely expressed among digestive organs whereas PPARalpha and gamma showed restricted expression. In the intestine, all PPARs are expressed after hatch, indicating that they play important roles in the physiology of the adult intestine.

Animals↗
PubMed2005

The significance of intraoperative Doppler ultrasonography in evaluating hepatic arterial flow when assessing the indications for the Appleby procedure for pancreatic body cancer.

BACKGROUND/PURPOSE: The Appleby procedure has been used in the surgical treatment of advanced gastric cancer. This procedure consists of a combined resection of the whole of the stomach, the body and tail of the pancreas, and the spleen, as well as resection of the celiac artery. This procedure can also be used for operative resection of cancer of the body of the pancreas. The hepatic arterial flow is supplied from the arcade of the supramesenteric artery. In the past, the extent of hepatic arterial flow after the celiac artery had been clamped was evaluated by finger palpation. However, this is not an objective method. METHODS: Here, we describe two patients with pancreatic body cancer, in one of whom the Appleby procedure was followed. However, in the other, this operation could not be performed because the residual blood supply to the liver would have been inadequate. The hepatic arterial flow was assessed using intraoperative Doppler ultrasonography (US) of the intrahepatic artery (arterial flow of segment 3). RESULTS: In case 1 (a 45-year-old man), the hepatic arterial flow prior to clamping of the celiac artery was 68.4 cm/s, and this flow was reduced to 22.1 cm/s after the clamping. The color and consistency of the liver surface remained good. Because there was adequate hepatic arterial flow after the celiac artery was clamped, the Appleby procedure was performed. However, in case 2 (a 65-year-old man), the hepatic arterial flow after the celiac artery had been clamped was reduced from 47.9 cm/s to 14.3 cm/s. The liver surface became dark and the liver shrank. In addition, there were various preoperative medical conditions in this patient. We decided not to proceed with the Appleby procedure. CONCLUSIONS: Intraoperative Doppler US measurement of the hepatic arterial flow is a useful technique, particularly in combination with the assessment of the color and tension of the liver, the age of the patient, and the extent of preoperative comorbidity, in determining whether an Appleby procedure is feasible.

Aged↗
PubMed2005

Mixed serous cystadenoma with mucinous cystadenoma of the pancreas.

We report a case of serous cystadenoma of the pancreas mixed with mucinous cystadenoma. A 65-year-old woman was admitted to our hospital for evaluation of a palpable, elastic, hard mass measuring 6 cm in diameter in the right upper quadrant of the abdomen. A diagnosis of mucinous cystadenocarcinoma of the pancreas was made, and pancreatoduodenectomy was performed. The tumor was composed of a dominant compartment of macroscopic cyst, and its thick wall was filled with numerous microscopic cysts. The light microscopy findings with hematoxylin and eosin staining, and by the periodic acid-Schiff reaction, were almost perfectly consistent with the characteristics of microcystic or glycogen-rich cystadenoma, but the apical portion of the cytoplasm of the neoplastic cells was stained with Alcian blue at pH 2.4 and by the mucicarmine method. Neoplastic cells containing epithelial acidic mucin are usually found in mucinous cystadenomas. No K-ras point mutations were detected at the sites where neoplastic cells were present, whether or not they contained epithelial acidic mucin. Pancreatic serous cystadenomas that include a mucinous-cystadenoma component are extremely rare, and the difference between serous and mucinous cystadenomas is not always distinct.

Aged↗
PubMed2005

Anatomy and histology of Virchow's node.

A regional lymphatic system is composed of the first, second, third and even fourth or much more intercalated nodes along the lymptatic route from the periphery to the venous angle or the thoracic duct. The third or fourth node is usually termed the last-intercalated node or end node along the route. Similarly, one of the supraclavicular nodes is known to correspond to the end node along the thoracic duct. It is generally called 'Virchow's node', in which the famous 'Virchow's metastasis' of advanced gastric cancer occurs. The histology of this node has not been investigated, although region-specific differences in histology are evident in human lymph nodes. We found macroscopically the end node in five of 30 donated cadavers. Serial sections were prepared for these five nodes and sections stained with hematoxylin and eosin. Histological investigation revealed that, on the inferior or distal side of the end node, the thoracic duct divided into three to 10 collateral ducts and these ducts surrounded the node. The node communicated with the thoracic duct and its collaterals at multiple sites in two to three hilus-like portions, as well as along the subcapsular sinus. Thus, the end node was aligned parallel to the thoracic duct. Moreover, the superficial and deep cortex areas of the end node were fragmented to make an island-like arrangement, which may cause the short-cut intranodal shunt. Consequenly, the filtration function of most of Virchow's node seemed to be quite limited.

Cadaver↗
PubMed2005

Biological similarities and differences between pancreatic intraepithelial neoplasias and intraductal papillary mucinous neoplasms.

BACKGROUND: Ever since the classification of pancreatic intraepithelial neoplasia (PanIN) was published, studies on the precursor lesions of pancreatic cancer have been advancing along a new directions, using standardized terminology. There are few studies that have examined the biological differences between PanIN and intraductal papillary mucinous neoplasm (IPMN) in detail. AIMS: PanIN and IPMN, which are similar in morphology, were compared using various indicators, with the aim of identifying the similarities and differences between the two. METHODOLOGY: A total of 46 PanINs and 37 ducts with IPMN were identified in 19 patients with invasive ductal carcinoma and 18 patients with IPMN. These PanINs and IPMNs were examined immunohistologically with respect to the expression patterns of HER2/neu, DPC4/Smad4, Akt/PKB, p53, cyclin A, Ki67, MUC1, and MUC2. RESULTS: Significant differences in the expression of MUC1 and MUC2 were observed between IPMNadenoma and PanIN-2 and between CIS and PanIN-3 (MUC1: p = 0.001 and p = 0.005, respectively; MUC2: p = 0.002 and p < 0.001, respectively). A significant difference in the p53 expression level was also observed between CIS and PanIN-3 (p = 0.015). CONCLUSIONS: In both IPMN and PanIN, the grade of atypism increased with increasing expression of HER2/neu, DPC4/Smad4, and Akt/PKB, along with progression in the process of multistage carcinogenesis. Although the expression levels of these factors reflected the grade of atypism, they did not reflect any differences in the grade of biological malignancy between IPMN and PanIN. On the other hand, MUC1 and MUC2 may serve as indicators of the direction of differentiation, i.e., either progression to IDAC or IPMN. Positivity for MUC1 was believed to suggest differentiation into IDAC, and positivity for MUC2 appeared to be indicative of differentiation into IPMN. Such indication of the direction of differentiation seemed to appear in PanIN1-2, even before abnormalities of HER2/neu, Akt/PKB, DPC4/Smad4, p53, and cyclin A expression began to be detected.

Aged↗
PubMed2005

[Theories and techniques for resection of the extrapancreatic nerve plexus in the head of the pancreas during a Whipple procedure for carcinoma of the pancreas--suggestions from the perspective of surgical anatomy and pathology].

Although various therapeutic modalities for carcinoma of the pancreas are available, "curative (R0) resection" is the most important. Thus, the aim of surgery for carcinoma of the pancreas is local complete resection of the carcinoma. We offer two suggestions for complete resection of carcinoma of the pancreas, which shows a strong invasive tendency around nerve fibers, during a Whipple procedure. 1. En bloc resection of the right side of nerve plexus of the superior mesenteric artery and the first and second nerve plexus of the pancreatic head should be performed. It is easy to perform this procedure when the superior mesenteric artery should be moved to the right side of the superior mesenteric vein through under this vein. 2. The entire cut end of the nerve plexus should be investigated during the operation using frozen specimens and confirmed to be negative for cancer. If the cut end is positive for cancer, additional resection of the nerve plexus should be performed to achieve curative resection. The reason is that it is impossible to completely investigate positive or negative carcinoma in the cut end of the nerve plexus after surgery, since the cut end is long and some specimens are deformed by formalin fixation.

Humans↗
PubMed2004

Neoplastic diseases of the papilla of Vater.

Although it is quite small, the papilla of Vater is an important part of the body. Carcinoma of the papilla may be one of the smallest cancers that can cause death. The 5-year survival rate after resection was 51%, which is not satisfactory. In this article, the topics discussed are (1) pathogenesis, (2) histological characteristics, and (3) the molecular biological characteristics of carcinoma of the papilla of Vater. From results obtained by the investigation of 576 autopsied and 51 resected cases, atypical epithelium was found most frequently in the common channel, where pancreatic juice and bile mix physiologically. Atypical epithelia may be a precursor of carcinoma of the papilla of Vater. Carcinoma of the papilla of Vater could be classified into two types histologically, an intestinal type and a pancreaticobiliary type. The prognosis of patients with the intestinal type was much better than that of patients with the pancreaticobiliary type. These two types of carcinoma should be treated by different operative procedures or adjuvant therapies. Regarding the molecular biological characteristics of carcinoma of the papilla of Vater; (1) K- ras mutation is mainly associated with the intestinal type, and carcinomas of the intestinal and pancreaticobiliary types may develop via different mechanisms; (2) p53 overexpression may play a role in tumor ulceration; and (3) p21/Waf1 overexpression was significantly correlated with a poor prognosis.

Ampulla of Vater↗
PubMed2004

Incidence of acute endophthalmitis after triamcinolone-assisted pars plana vitrectomy.

PURPOSE: To report the incidence of acute endophthalmitis after triamcinolone acetonide-assisted pars plana vitrectomy (PPV). DESIGN: A retrospective multicenter interventional case series collected over 23 months. METHODS: We retrospectively reviewed the charts of all patients who underwent triamcinolone-assisted PPV at seven academic clinical centers or eye hospitals from January 2002 to November 2003. RESULTS: Of a total of 1,886 cases, only 1 case showed acute endophthalmitis due to Staphylococcus epidermidis (0.053%). No other cases showed any signs of postoperative endophthalmitis. CONCLUSION: Intraoperative use of triamcinolone during PPV is not a high risk factor for acute endophthalmitis.

Acute Disease↗
PubMed2004

Cystic neoplasm of the pancreas: a Japanese multiinstitutional study of intraductal papillary mucinous tumor and mucinous cystic tumor.

The Japan Pancreas Society performed a multiinstitutional, retrospective study of 1379 cases of intraductal papillary mucinous tumor (IPMT) and 179 cases of mucinous cystic tumor (MCT) of the pancreas. Clinicopathologic features and postoperative long-term outcomes were investigated. IPMT were most frequently found in men and in the head of the pancreas. In contrast, all patients with MCT were women. Ovarian-type stroma were found in only 42.2% of the MCT cases. Prognostic indicators of malignant IPMT included advanced age, positive symptoms, abundant mucous secretion, presence of large nodules and/or large cysts, remarkable dilatation of the main pancreatic duct, and main duct- or combined-type IPMT. Advanced age, positive symptoms, and presence of large nodules and/or large cysts were predictive of malignant MCT. The 5-year survival rate of IPMT patients was 98%-100% in adenoma to noninvasive carcinoma cases, 89% in minimally invasive carcinoma cases, and 57.7% in invasive carcinoma cases. The 5-year survival rate of MCT patients was 100% in adenoma to minimally invasive carcinoma cases and 37.5% in invasive carcinoma cases. In conclusion, IPMT and MCT show distinct clinicopathologic and prognostic differences. The results from this study may contribute to the diagnosis and treatment of IPMT and MCT.

Adenocarcinoma, Mucinous↗