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Dive into the research topics where Hajime Yamasaki is active.

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Featured researches published by Hajime Yamasaki.


World Journal of Surgery | 1995

Function of the sphincter of Oddi in patients with juxtapapillary duodenal diverticula: evaluation by intraoperative biliary manometry under a duodenal pressure load

Satoru Miyazaki; Tsuguo Sakamoto; Masahiko Miyata; Yoshio Yamasaki; Hajime Yamasaki; Keiji Kuwata

The purpose of this study was to elucidate the function of the sphincter of Oddi (SO) in patients with juxtapapillary duodenal diverticula (JDDs). The SO function was evaluated by intraoperative biliary manometry in three groups of patients. Group 1 consisted of nine patients with JDDs and a dilated common bile duct (CBD) (diameter > 10 mm). Group 2 consisted of six patients with JDDs and a normal-sized CBD (diameter < 10 mm). Group 3 consisted of 26 patients without JDDs and with normal-sized CBDs.In the absence of a duodenal pressure load, the patients in group 1 demonstrated a lower baseline SO pressure and lower resistance of the biliary outflow than patients in group 3. They also demonstrated a lower baseline SO pressure and shorter decay time (which represented terminal biliary ductal resistance) than patients in group 2. In the presence of a duodenal pressure load of 300 mm H2O, the patients in group 1 demonstrated a lower incidence of phasic SO contractions, a higher baseline SO pressure, and a higher resistance of the biliary outflow than group 2 and group 3 patients. The decay time in group 1 and group 2 patients was higher than that of group 3 patients. Based on these findings, we conclude that the SO function in patients with JDDs is impaired owing in part to long-standing compression of the terminal biliary ductal system by a distended JDD associated with a rise in intraduodenal pressure in daily life.


Chemotherapy | 2007

Upregulation of enzymes metabolizing 5-fluorouracil in colorectal cancer.

Satoshi Matsusaka; Hajime Yamasaki; Masakazu Fukushima; Ichiro Wakabayashi

Background: The purpose of this study was to compare the activities of various enzymes, participating in the metabolism of 5-fluorouracil, between colorectal cancer and nontumor tissues and to investigate the association of the enzyme activities with clinicopathological backgrounds. Methods: Activities of seven enzymes involved in nucleic acid metabolism – orotate phosphoribosyltransferase (OPRT), ribonucleotide reductase (RNR), thymidylate synthase, dihydropyrimidine dehydrogenase, thymidine phosphorylase, uridine phosphorylase and thymidine kinase (TK) – were measured in tumor and nontumor tissues from 28 patients who were operated on for colorectal cancers. Results: OPRT, thymidylate synthase, RNR, thymidine phosphorylase, uridine phosphorylase and thymidine kinase activities were significantly higher in tumor areas than in nontumor areas. OPRT showed the highest T/N ratio (the ratio of each enzyme activity in tumor areas to that in nontumor areas). The T/N ratio of RNR activity showed a tendency to be associated with lymph node metastasis and Dukes classification. Conclusion: The results suggest that OPRT is a main enzyme participating in the phosphorylation of 5-fluorouracil and has an important role in tumor growth. The T/N ratio of RNR may be predictive of tumor progression.


The Annals of Thoracic Surgery | 1997

Mediastinoscopic Extirpation of Mediastinal Ectopic Parathyroid Gland

Kiyoshi Ohno; Keiji Kuwata; Yoshio Yamasaki; Hajime Yamasaki; Nobutaka Hatanaka; Shigetaka Yamamoto

We report a case of a 50-year-old man with hyperparathyroidism secondary to chronic renal failure who underwent extirpation of a mediastinal ectopic parathyroid gland by a transcervical approach under mediastinoscopy. This procedure provides an excellent approach to the mediastinal ectopic parathyroid gland, and is less invasive than median sternotomy or thoracotomy.


Surgery Today | 2003

Occult gallbladder carcinoma diagnosed by a laparoscopic cholecystectomy.

Satoshi Matsusaka; Hajime Yamasaki; Yoshihiro Kitayama; Toshihiro Okada; Shigeto Maeda

AbstractPurpose. A laparoscopic cholecystectomy (LC) has become a common treatment modality. The incidence of occult gallbladder carcinoma (GC) diagnosed by LC has increased; however, the effects of a radical second operation after LC have not yet been demonstrated. In this study we examine the outcome of such further surgical intervention. Methods. We clinicopathologically studied occult GC diagnosed by LC. We analyzed the results to establish a therapeutic protocol for repeated surgical intervention, and to determine whether the incidence of occult GC has increased. Results. GC, which invaded the mucosa and exhibited a noninvading biliary wedge (m+/bm−), did not recur during the follow-up. GC, which invaded the subserosa (ss)+/bm− and thus required a second operation, did not recur, and the patients had a satisfactory prognosis, both short-term and long-term. One of the patients with ss+/bm+ developed peritoneal dissemination after secondary surgical intervention. Conclusion. After evaluating the clinical outcome of a second operation for the treatment of GC, we concluded that, even for advanced stage patients, repeated surgical intervention may improve the prognosis of GC and thus should be considered, when encountering such patients.


World Journal of Surgery | 2003

Immunohistochemical evaluation for intraoperative rapid pathological assessment of the gastric margin.

Satoshi Matsusaka; Tomohumi Nagareda; Hajime Yamasaki; Yoshihiro Kitayama; Toshihiro Okada; Shigeto Maeda

In patients undergoing surgery for gastric cancer, as the resection area is difficult to define preoperatively, we define the resection area by intraoperative rapid pathological assessment of the resected margin. In some patients, however, the result of postoperative assessment of a permanent section differs from the result obtained intraoperatively. In this study we explored methods of improving the accuracy of intraoperative pathological assessment. Of the patients who underwent surgery for gastric cancer at Takarazuka Municipal Hospital, between April 2000 and July 2001, intraoperative pathological assessment of the resection margin was performed in 34 because it could not be accurately defined preoperatively. The intraoperative assessment consisted of touch smear cytological examination and hematoxylin and eosin (HE) and cytokeratin (CK) histological examination. The time required to perform cytological examination and HE and CK immunohistochemistry by this modified method, which uses an ENVISION Kit/HRP, was approximately 20 minutes for each procedure. Touch smear cytological examination gave false positive results in 3 of 34 patients (8.8%). Of the 14 patients preoperatively diagnosed with signet-ring cell carcinoma, intraoperative HE histological analysis yielded a false negative result in one (7.1%). The results of CK histological assessment of these patients were all consistent with those of postoperative examination of permanent sections. Of the 20 patients preoperatively diagnosed with non-signet-ring cell carcinoma, HE analysis yielded a false negative result in one (5%). The results of CK histological assessment of these patients were all consistent with those of postoperative examination of permanent sections. Our modified CK staining method with the ENVISION Kit/HRP allows intraoperative pathological assessment to be performed accurately and rapidly. This method is more useful than HE immunohistochemistry for the assessment of resected gastric margins.


Cancer Immunology, Immunotherapy | 1990

Relationship between general or specific immunoreactivity and prognosis in postoperative patients with hepatocellular carcinoma

Hajime Yamasaki; Eizo Okamoto; Toshinori Komatsu; Yuich Manabe; Sohei Shinka

SummaryThe levels of a variety of immunological parameters were examined in 203 preoperative patients with hepatocellular carcinoma (HCC) at various stages (I–IV). The changes in the peripheral blood lymphocyte (PBL) count, the serum level of immunosuppressive acidic protein and the degree of the skin reaction to purified protein derivative were associated significantly with the stage of HCC progression. However, the percentages of lymphocyte subsets, mitogenic responsiveness of PBL and serum immunoglobulin concentration remained at the levels of stage I. Further study demonstrated that in patients undergoing hepatic artery ligation, there were statistically significant correlations between the PBL count, immunosuppressive acidic protein concentration and intensity of the skin reaction to purified protein derivative, assayed 1 month after surgery, and the prognosis. HCC-specific immunity was examined in 34 patients treated by hepatic resection or hepatic artery ligation using in vitro responses of PBL to HCC extracts (ATS test). This test was performed using culture medium containing added arginine. None of the PBL from the patients showed a positive response to allogeneic HCC extracts, but the PBL from 12 patients (9 hepatic resections, 3 hepatic artery ligations) were stimulated significantly (SI ⩾ 2.5) with autologous HCC extracts. In 7 of 9 hepatic resection patients who were positive in the ATS test, tumor recurrence was identified. Statistical analysis indicated that the ATS test result was significantly correlated with tumor recurrence in hepatic resection patients. Autologous-PBL-stimulating activities were isolated in a fraction at pH 8.3 and in fractions at pH 6.7–7.0 by chromatofocusing of the crude extract. Although identification of the HCC-specific antigen remains to be done, use of the above fractions may simplify the ATS test procedure and improve its sensitivity.


World Journal of Surgery | 1998

Role of Helicobacter pylori in Residual Gastritis after Distal Partial Gastrectomy

Shigetaka Yamamoto; Yoshio Yamasaki; Keiji Kuwata; Hajime Yamasaki; Yukihiro Nishida; Yasushi Kobayashi

Abstract. We studied the relation betweenHelicobacter pylori and residual gastritis in 28 patients with gastric cancer on whom distal partial gastrectomy with Billroth I reconstruction was performed over a 13-month period. They were subjected to serologic testing along with endoscopic and histologic examinations before operation and at 3, 6, and 12 months after operation. Anti-H. pylori immunoglobulin G (IgG) and serum gastrin levels were measured by serologic tests. The presence or absence of gastritis was determined endoscopically, and gastric mucosal hexosamine levels were determined. Gastritis was measured quantitatively by histologic examination in specimens taken from the gastric mucosa using Rauws’ score. After the initial histologic evaluation we divided the H. pylori-positive patients into two groups: those with a Rauws’ score of 0 to 3 (“weak” gastritis group), and those with a Rauws’ score of 4 to 10 (“strong” gastritis group), allowing us to compare the results of our three postoperative histologic examinations of the two groups for possible significant differences. Our endoscopic examinations showed gastric mucosal inflammatory changes in both H. pylori-positive andH. pylori-negative patients at 3, 6, and 12 months after operation, but there was no significant difference between these two groups at any point. During the histologic examinations, however, anti-H. pylori IgG assay had become negative in several patients in the “weak” gastritis group at 3 months after operation and was found to have become negative in 78% of all patients in that group 12 months after operation. In contrast, in the “strong” gastritis group H. pylori infection was still evident in the patients 12 months after operation, suggesting that “strong” histologic gastritis may have some connection to H. pyloriinfection, whereas “weak” histologic gastritis has no such connection. The gastric mucosal hexosamine level was higher in the “weak” gastritis group than in the “strong” gastritis group both before operation and at 6 and 12 months, indicating some relation between gastric inflammatory changes and hexosamine levels in gastric mucosa. It further suggested the possibility that H. pyloriplays a role in destroying gastric mucosa by depleting mucin, thus acting as one (though not the only) cause of residual gastritis after distal partial gastrectomy. In conclusion, we found evidence that there is a relation between residual gastritis and H. pyloriinfection, but H. pylori is not the sole cause of residual gastritis after gastric surgery. A causal relation is difficult to detect by simple analysis of histologic findings or by endoscopic observation or clinical symptoms alone.


Jpn J Gastroenterol Surg, Nihon Shokaki Geka Gakkai zasshi | 2005

A Case of Metastatic Gastric Cancer from Ovarian Cancer

Yoshihiro Kitayama; Yousuke Yoden; Nobuhiro Okamoto; Hajime Yamasaki; Tomohisa Nagareda

症例は46歳の女性で, 心窩部不快感と体重減少を主訴に紹介受診され, 精査にて進行胃癌の診断にて手術を施行した. 術後化学療法施行中に下腹部の腫瘤が出現し, 画像検査により卵巣癌が疑われたため, 子宮全摘術・両側付属器摘出術を施行した. しかし, その後の病理学的検査にて両者を比較検討および前回手術の胃標本を再検した結果, 胃の病変は漿膜から粘膜下層までにとどまっておりCA125の免疫染色にて両者が陽性像を呈する卵巣癌の胃転移が強く疑われた.


Nihon Rinsho Geka Gakkai Zasshi (journal of Japan Surgical Association) | 2007

A CASE OF IDIOPATHIC OMENTAL HEMATOMA

Koichiro Ohashi; Hajime Yamasaki; Uko Cho; Hideaki Sasaoka; Masayuki Nishino


Nihon Rinsho Geka Gakkai Zasshi (journal of Japan Surgical Association) | 2000

SIX CASES OF LAPAROSCOPIC CHOLECYSTECTOMY TO LEFT-SIDED GALLBLADDER

Tai-ping Huang; Yoshio Yamasaki; Hajime Yamasaki; Yuichi Fukui; Nobutaka Hatanaka; Shinichiroh Okuno; Keiji Kuwata

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Keiji Kuwata

Hyogo College of Medicine

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Eizo Okamoto

Hyogo College of Medicine

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