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Biomedical subjects

M Esaki

Publications and source records attributed to M Esaki.

At least 19 recordsLinked to original sources
PubMed2006

Randomized clinical trial of hepatectomy using intermittent pedicle occlusion with ischaemic intervals of 15 versus 30 minutes.

BACKGROUND: The optimal ischaemic interval during hepatectomy with intermittent pedicle occlusion (IPO) remains to be established. The aim of the present randomized clinical trial was to compare the short-term outcome of hepatectomy using IPO with an ischaemic interval of 15 versus 30 min. METHODS: Between October 2002 and September 2004, 108 consecutive patients scheduled to undergo hepatectomy without bilioenterostomy were enrolled. During liver transection, IPO was performed with an ischaemic interval of either 15 min with 5 min of reperfusion (standard group, SG) or 30 min with 5 min of reperfusion (prolonged group, PG). After randomization and subsequent exclusion of certain patients, 44 patients in the SG and 48 in the PG were analysed. RESULTS: The mean(s.d.) bilirubin ratio (serum total bilirubin level on day 2 after operation divided by the preoperative level) was 1.6(0.8) in the SG and 1.7(0.8) in the PG (P = 0.874). The transection area per unit transection time was significantly greater in the latter group (median (range) 1.0 (0.4-2.1) versus 0.8 (0.0-1.5) cm(2)/min; P = 0.046). CONCLUSION: There was no difference in the bilirubin ratio when IPO was carried out for 30 or 15 min. By extension of IPO to 30 min, a greater resection area per unit time was possible with preservation of remnant liver function.

Adult↗
PubMed2005

Comparison of capsule endoscopy and enteroscopy with the double-balloon method in patients with obscure bleeding and polyposis.

BACKGROUND AND STUDY AIMS: Video capsule endoscopy and double-balloon enteroscopy (DBE) are novel methods of enteroscopy. The aim of this investigation was to compare the value of CE and DBE in the diagnosis of small-intestinal pathology. PATIENTS AND METHODS: Thirteen patients with gastrointestinal bleeding of obscure origin and nine patients with known gastrointestinal polyposis were examined using antegrade or retrograde DBE, and the most distal or proximal site in the explored small intestine was marked by submucosal injection of sterilized ink. The patients were then evaluated by CE. Video images obtained by CE were reviewed by an observer who was blinded to the DBE findings. RESULTS: DBE identified positive findings in 12 patients (54.5 %). CE identified positive findings in the area explored by DBE in eight patients (36.4 %), and in the unexplored area in 11 patients (50.0 %). The overall diagnostic yield in the area explored by DBE did not differ between the two procedures. The enteroscopic findings in the area explored by DBE were concordant in 12 of 13 patients with gastrointestinal bleeding of obscure origin. In patients with polyposis, the diagnoses were discordant in three patients, in whom CE failed to detect any polyp. In two of three polyposis patients with concordant positive findings, DBE detected a larger number of polyps than CE did. CONCLUSIONS: DBE appears to be superior to CE in the diagnosis of small-intestinal polyps, whereas the value for diagnosing gastrointestinal bleeding of obscure origin is similar in the two procedures.

Adult↗
PubMed2004

Small invasive colonic cancer occurring in a hyperplastic polyp.

We report a case of advanced colon cancer which was supposed to have arisen from a hyperplastic polyp in a 68-year-old man. Colonoscopy revealed a depressed reddish area with a surrounding elevated lesion that was of a faded color compared with the normal mucosa. After the mucosal surface had been sprayed with crystal violet dye, magnifying colonoscopy showed an amorphous area in the central depression and the surrounding, slightly elevated lesion had an asteroid pattern. The depressed area was therefore considered to be a colonic cancer surrounded by a hyperplastic polyp. Endoscopic ultrasonography showed that the lesion was infiltrating further than the deep submucosal layer and it was therefore decided to treat the patient by laparoscopically assisted right hemicolectomy. The depressed lesion was found to be a well-differentiated adenocarcinoma invading the muscularis propria (diagnosed as IIc + IIa-like advanced adenocarcinoma). The surrounding flat elevated lesion was found to be hyperplastic mucosa. No adenomatous lesions were found. There have been few reported cases in which a preoperative diagnosis of carcinoma in a hyperplastic polyp has been made, but the possibility of carcinogenesis from hyperplastic polyps has come under consideration recently. This case was considered to be important because it raises the possibility that nonpolypoid cancer can develop from a hyperplastic polyp.

Adenocarcinoma↗
PubMed2003

CCR4 is an up-regulated chemokine receptor of peripheral blood memory CD4+ T cells in Crohn's disease.

Several chemokine receptors are expressed selectively on the surface of T cells depending on their polarization. The aim of this study was to characterize chemokine receptor expression in peripheral blood memory T cells in Crohn's disease (CD) and ulcerative colitis (UC), and to correlate the expression with disease activity. Peripheral blood mononuclear cells (PBMCs) were obtained from 24 patients with CD, 30 patients with UC, 24 normal controls and 10 disease controls. PBMCs were stained by anti-CCR3, CCR4, CCR5, CXCR3, CD4, CD8, CD45RO and beta 7 integrin, and the expression of the chemokine receptors were determined by flow cytometry. CCR4 expression on memory T cells was significantly lower in UC than in CD or normal controls, and that of memory CD4+ T and beta 7(high) memory CD4+ T cells was significantly higher in CD than in UC or normal controls. CCR4 expression on memory CD4+ T cells exhibited significant positive correlation with disease activity in CD, and this decreased significantly after treatment. Such a decrease was not found in the disease controls. CCR5 and CXCR3 expression on memory CD8+ T cells was significantly lower in CD than in normal controls. CXCR3 expression on beta 7(high) memory CD4+ T and CXCR3 expression on memory CD8+ T cells were lower in UC than in normal controls. These findings suggest that in peripheral blood memory T cells, chemokine receptor expression is different between CD and UC. Enhancement of CCR4 and suppression of CCR5 and CXCR3 seem to be the characteristic chemokine receptor profile in peripheral blood memory T cells of CD.

Acute Disease↗
PubMed2003

A case of multicentric gastric carcinoids without hypergastrinemia.

We have encountered an unusual case of gastric carcinoid tumors. Gastroscopic examination of a 71-year-old male patient showed eight smooth protrusions at the greater curvature of the gastric body, some of which had central depressions. Endoscopic ultrasonography demonstrated that the largest tumor (2.6 cm in diameter) was located in the submucosal layer. The patient had a normal serum gastrin level and was negative for antiparietal cell antibody. The patient was also found to have a pituitary tumor, an adenomatous goiter, and bilateral Warthin's tumors of the parotid glands. Histological examination of the resected stomach identified 12 discrete carcinoid tumors. There was no evidence of atrophic gastritis or of endocrine cell micronests. No mutations of the MEN1 gene were found on genomic DNA analysis. Despite the multiplicity of carcinoid tumors, we diagnosed type 3 gastric carcinoid in this patient.

Aged↗
PubMed2003

Accuracy of radiographic assessment for the diagnosis of invasion depth in small invasive colorectal cancer.

Radiographic findings of 113 submucosally invasive colorectal cancers (CRCs) 10 mm. 47 CRCs had invaded the submucosa superficially while 66 CRCs had invaded deeply. The concordance rate in the assessment of radiology was 90.3% in smooth surface, 92.9% in central barium fleck, 90.3% in fold convergency and 79.6% in eccentric rigidity. Positive predictive value of central barium fleck for deep submucosal invasion was significantly higher in CRCs>10 mm than in those 10 mm. These findings suggest that barium radiography is a procedure which can give useful information in prediction of invasion depth in CRCs <or=10 mm in size.

Barium Sulfate↗
PubMed2002

Endosonographic features of Brunner's gland hamartomas which were subsequently resected endoscopically.

BACKGROUND AND STUDY AIMS: Brunner's gland hamartomas are uncommon duodenal submucosal tumors. We aim to describe their morphological characteristics, with particular attention to the endosonographic features. PATIENTS AND METHODS: We reviewed the radiological, endoscopic, endosonographic, and histological findings from six Brunner's gland hamartomas which were completely removed by endoscopic resection. RESULTS: The lesions appeared as broad-based, sessile, or pedunculated submucosal tumors, measuring 0.7 to 2 cm in maximal diameter. Three lesions contained tiny dimple-like depressions on the surface; in one lesion these were only recognized following the use of an endoscopic dye-spraying technique. All the lesions could be safely removed by endoscopic resection after endosonographic confirmation of the layer origin within the submucosa. The internal echo structure of the tumors appeared to be solid echogenic in two, simple cystic in two, and multicystic in the remaining two lesions. In three lesions with an indistinct boundary, some stromal proliferation and solid Brunner's glands were recognized in an area extending from the mucosa to the submucosa. These endosonographic features corresponded to histological findings comprising stromal proliferation and various degrees of solid and cystic glandular Brunner's glands. CONCLUSIONS: Brunner's gland hamartoma is characterized endosonographically by a heterogeneous solid and/or cystic mass within the submucosa.

Adult↗
PubMed2002

Is endoscopic ultrasonography indispensable in assessing the appropriateness of endoscopic resection for gastric cancer?

BACKGROUND AND STUDY AIMS: Endoscopic resection is increasingly being used in the treatment of early gastric cancer. The aim of the present study was to investigate the accuracy of pretherapeutic staging techniques for assessing the appropriateness of endoscopic resection. PATIENTS AND METHODS: Both endoscopy and endosonography were carried out at our institution in the treatment of 234 early gastric cancers, with histological confirmation of malignancy following surgical resection (137 lesions) or endoscopic resection (97 lesions). The accuracy in detecting intramucosal cancer with each of the diagnostic procedures was assessed. RESULTS: The accuracy rates for detecting intramucosal cancer using endoscopy and endosonography were calculated as 84 % (197 of 234) and 78 % (182 of 234), respectively. The accuracy tended to be lower in lesions located in the upper third of the stomach, in those measuring 2 cm or more in diameter, and in those with an undifferentiated histology with ulcer fibrosis. However, there were no significant differences in the accuracy rates between endoscopy and endosonography. Precise staging was achieved by endoscopy alone in 103 of 109 differentiated adenocarcinomas without ulcer fibrosis, where the lesions measured less than 2 cm in diameter. CONCLUSIONS: Endoscopic resection is indicated in intramucosal gastric cancer lesions showing differentiated histology, no ulcer fibrosis and a diameter of less than 2 cm. EUS may additionally be used for further evaluation in these patients.

Endosonography↗
PubMed2001

Intraoperative enteroscopy detects more lesions but is not predictive of postoperative recurrence in Crohn's disease.

BACKGROUND: The aim of this investigation was to elucidate the clinical value of intraoperative enteroscopy (IOE) for Crohn's disease, and to determine the value of IOE in predicting recurrent disease. METHODS: In this study 27 patients requiring surgery were examined by both preoperative radiography and IOE. The findings obtained by these procedures in the remnant small intestine were compared. In 19 patients, the clinical course and colonoscopic or radiographic findings after surgery were analyzed. RESULTS: Intestinal lesions were identified in 23 patients by IOE, and in 19 patients by radiography. Longitudinal ulcers were equivalently detected by IOE (63%) and radiography (56%), whereas small ulcers and inflammatory polyps were less frequently detected by radiography than by IOE (37% vs 74% and 19% vs 33%, respectively). Neither the presence nor the distribution of IOE findings was related to postoperative recurrence. CONCLUSIONS: Whereas IOE demonstrates small intestinal lesions in detail, the procedure alone cannot predict postoperative recurrence in Crohn's disease.

Adolescent↗
PubMed2001

Sciatic nerve regeneration in rats induced by transplantation of in vitro differentiated bone-marrow stromal cells.

Bone marrow stromal cells (MSCs) are multipotent stem cells that have the potential to differentiate into bone, cartilage, fat and muscle. We now demonstrate that MSCs can be induced to differentiate into cells with Schwann cell characteristics, capable of eliciting peripheral nervous system regeneration in adult rats. MSCs treated with beta-mercaptoethanol followed by retinoic acid and cultured in the presence of forskolin, basic-FGF, PDGF and heregulin, changed morphologically into cells resembling primary cultured Schwann cells and expressing p75, S-100, GFAP and O4. The MSCs were genetically engineered by transduction with retrovirus encoding green fluorescent protein (GFP), and then differentiated by treatment with factors described above. They were transplanted into the cut ends of sciatic nerves, which then responded with vigorous nerve fibre regeneration within 3 weeks of the operation. Myelination of regenerated fibers by GFP-expressing MSCs was recognized using confocal and immunoelectron microscopy. The results suggest that MSCs are able to differentiate into myelinating cells, capable of supporting nerve fibre re-growth, and they can therefore be applied to induce nerve regeneration.

Animals↗
PubMed2001

Cap polyposis of the colon and rectum: an analysis of endoscopic findings.

BACKGROUND AND STUDY AIMS: Because of the rarity of cap polyposis of the colon and rectum, the endoscopic features of this condition have not been specified to date. The aim of this study is to characterize the endoscopic features of cap polyposis. PATIENTS AND METHODS: The diagnosis of cap polyposis was established by histologic findings in specimens obtained endoscopically or surgically from four patients. Colonoscopic findings in the four patients were retrospectively reviewed. RESULTS: The endoscopic features were divided into semipedunculated type (three patients) and flat-topped protruding type (one patient). In the semipedunculated type, the polyps were characterized by reddish protrusions of various configurations with eroded surface in the rectosigmoid colon. In the remaining patient, all the lesions were flat protrusions with a reddish central depression. The polyps of both types became smaller in size and fewer in number at the proximal part of the sigmoid colon. Multiple white specks were observed in the intervening mucosa in all four patients. CONCLUSIONS: The prominence of the polyps at the distal part of the colon and rectum and multiple white specks in the intervening mucosa seem to be the additional endoscopic features suggestive of cap polyposis.

Adult↗
PubMed2001

Binding properties of Bacillus thuringiensis Cry4A toxin to the apical microvilli of larval midgut of Culex pipiens.

Cry4A is a dipteran-specific delta-endotoxin produced by Bacillus thuringiensis, and toxic to Culex pipiens (mosquito) larvae. The immunohistochemical staining of the midgut sections of C. pipiens larvae revealed that Cry4A bound in vitro and in vivo to the microvilli of the epithelial cells of posterior midgut and gastric caecae. The binding of digoxigenin-labeled Cry4A (DIG-Cry4A) to the apical microvilli was almost abolished in the presence of excess unlabeled Cry4A, suggesting that the binding of Cry4A to the microvilli was specific. Several Cry4A-specific binding proteins were detected using the ligand blotting technique with DIG-Cry4A. Moreover, an insertion assay was done, where the binding of DIG-Cry4A to the BBMVs was completely irreversible and did not compete with excess unlabeled Cry4A. On the basis of these results, we propose a schematic interpretation for the binding process of Cry4A.

Animals↗
PubMed2000

Cystic submucosal tumors in the gastrointestinal tract: endosonographic findings and endoscopic removal.

BACKGROUND AND STUDY AIMS: The aim of the present study was to describe the endosonographic findings in gastrointestinal cystic submucosal tumors. PATIENTS AND METHODS: The endosonographic and clinicopathological findings in 51 patients with a confirmed diagnosis of cystic submucosal tumors were reviewed. RESULTS: Endosonographically, cystic submucosal tumors were classified into simple cystic, multicystic, and solid cystic tumor types. The simple cystic tumor type was frequently identified in cysts, and rarely in Brunner's gland hamartomas or in heterotopic gastric mucosa. The multicystic tumor type was common in lymphangiomas, followed by gastric cystic malformations, hemangiomas, and Brunner's gland hamartomas. The solid cystic tumor type included duplication cysts, heterotopic gastric mucosa, heterotopic pancreas, myogenic tumors with advanced cystic degeneration, and gastric tuberculomas. Based on the endosonographic findings, 14 lesions were safely treated with endoscopic removal, using in particular the unroofing technique (cutting off the upper part of the tumors) in nine lesions. CONCLUSIONS: Endosonography is a useful diagnostic modality for investigating cystic submucosal tumors.

Cysts↗
PubMed2000

A practical technique to postfix nanogold-immunolabeled specimens with osmium and to embed them in Epon for electron microscopy.

Nanogold is a tiny gold probe, freely diffusible in cells and tissues, and is suitable for pre-embedding immunohistochemistry. However, it is necessary to develop Nanogold to a larger size so that it can be observed by conventional transmission electron microscopy. Silver enhancement is usually used for visualizing Nanogold, but the silver shell produced is unstable in OsO(4) and often becomes invisible after OsO(4) postfixation, which is necessary for good visualization of ultrastructure. We used silver enhancement with silver acetate, followed by gold toning with chloroauric acid, to replace the silver shell with a more stable gold in order to observe Nanogold after osmium fixation and Epon embedding. This technique is applicable to various intra- and extracellular antigens. For correlative observation of immunolabled specimens by light and electron microscopy, specimens adhered to slideglasses were embedded in Epon under non-adhesive plastic film. By heating the Epon sheets after polymerization, these supports were removed without difficulty and provided easy correlative observation.

Animals↗
PubMed1999

Two distinct mechanisms drive protein translocation across the mitochondrial outer membrane in the late step of the cytochrome b(2) import pathway.

The import of cytochrome b(2) into mitochondria consists of two steps. The translocation of the first part of the presequence across the inner membrane is coupled with the translocation of the tightly folded heme-binding domain across the outer membrane and requires a membrane potential DeltaPsi and the functions of mitochondrial Hsp70 (mHsp70) in the matrix. Once the heme-binding domain has passed the outer membrane, the translocation of the rest of the polypeptide chain across the outer membrane becomes independent of DeltaPsi and mHsp70. Here we analyzed the late DeltaPsi- and mHsp70-independent step in the transport of cytochrome b(2) fusion proteins into the intermembrane space (IMS). The import of the cytochrome b(2) fusion proteins containing two protein domains linked by a spacer segment into mitochondria was arrested at a stage at which one domain folded on each side of the outer membrane, along the pathway that is consistent with the stop-transfer model. The mature-size form of the translocation intermediate could move across the outer membrane in both directions, and the stabilization of the protein domain in the IMS promoted the forward translocation. On the other hand, the intermediate-size form of the translocation intermediate, which retains the anchorage to the inner membrane, was transported into the IMS independently of the stability of the protein domain in the IMS. These results suggest that two distinct mechanisms, the Brownian ratchet and the anchor diffusion mechanisms, can operate for the transmembrane movement of the mature-size form and the intermediate-size form, respectively, of cytochrome b(2) species.

Animals↗