Biomedical subjects

I Miyazaki

Publications and source records attributed to I Miyazaki.

At least 19 recordsLinked to original sources

PubMed1998

Protective effects of nicergoline against hydrogen peroxide toxicity in rat neuronal cell line.

We examined the effects of nicergoline on hydrogen peroxide (H2O2)-induced neurotoxicity in cultured rat neuronal cell line (B50). H2O2 induced death of B50 cells in a dose-dependent manner. The H2O2-induced neuronal cell death was significantly decreased in B50 cells maintained in the presence of nicergoline. We compared the levels of antioxidants (glutathione, catalase and superoxide dismutase) in nicergoline-treated and untreated B50 cells. Lipid peroxidation products (thiobarbituric acid reactive substances, TBARS) levels were also measured. Cultures treated with nicergoline had higher levels of catalase activity. TBARS level was significantly lower in nicergoline-treated cells than in untreated cells. Our results suggest that nicergoline may induce the up-regulation of intracellular antioxidant defences and protect the neuronal cells against oxidative stress.

Animals↗

PubMed1998

Effects of repeated cyclosporin A administration on iminodipropionitrile-induced dyskinesia and TRE-/CRE-binding activities in rat brain.

To clarify the involvement of immunophilin ligands in the pathogenesis and pathophysiology of dyskinesia, we examined the effects of repeated administration of cyclosporin A (CsA) on rat dyskinesia induced by repeated injection of iminodipropionitrile (IDPN 100 mg/kg, i.p., for 7 days). The addition of CsA treatment (5 mg/kg, s.c., 1 h before each IDPN injection) exacerbated IDPN-induced dyskinesia. In the group treated with both CsA and IDPN, the concentration of dopamine was significantly increased in the striatum and nucleus accumbens compared with the group treated with IDPN alone. Furthermore, in the electrophoretic mobility shift assay, the injection of CsA + IDPN increased binding activities of transcription factors to the TPA (12-O-tetradecanoylphorbol-13-acetate)-responsive element (TRE) and to the cAMP response element (CRE) in the striatum and nucleus accumbens, compared with those in rats treated with IDPN alone. The levels of D1-receptor mRNA in the striatum were significantly decreased in the IDPN-treated rats but were at the control level in the rats given CsA + IDPN. These findings suggest that the behavioral aggravation of the IDPN-induced dyskinesia caused by CsA administration may be due to the acceleration of the pre- and post-synaptic dopaminegic systems via activation of transcription factors which bind upstream to tyrosine hydroxylase and D1-receptor genes, and that the immunophilin binding agents such as CsA are involved in this aggravated dyskinesia.

3,4-Dihydroxyphenylacetic Acid↗

PubMed1998

Prognostic significance of c-erbB-2 gene expression in the poorly differentiated type of adenocarcinoma of the stomach.

Prognostic significance of c-erbB-2 gene abnormalities is unclear in the poorly differentiated type of gastric carcinoma, because the abnormalities of this gene have been reported to be restricted to the differentiated type of gastric carcinoma. In this study, correlation of c-erbB-2 gene amplification/overexpression of mRNA and protein were studied in the poorly differentiated type of gastric carcinoma. c-erbB-2 gene amplification determined by the slot-blot hybridization was observed in 11 (13%) of 82 gastric cancer, and 8 of 11 tumors were poorly differentiated. In addition, c-erbB-2 mRNA expression was studied by the reverse transcriptase-polymerase chain reaction. Four (17%) of 24 tumors showed overexpression of c-erbB-2 mRNA, and all these four exhibited morphologically a poorly differentiated type. Among 157 poorly differentiated gastric cancers, 20 (13%) tumors showed immunohistochemically c-erbB-2 protein expression. These tumors had significantly higher incidences of larger tumor, serosal invasion-positive tumors, node-positive tumor, or peritoneal dissemination-positive tumor than those without c-erbB-2 expression. Furthermore, patients with c-erbB-2 protein overexpression ran poorer prognoses than those without c-erbB-2 expression. From these results, we conclude that expression c-erbB-2 tissue status may be a good prognostic indicator in poorly differentiated gastric carcinoma.

Adenocarcinoma↗

PubMed1998

[Phase I study of TAT-59 (a new antiestrogen) in breast cancer. TAT-59 Study Group].

Phase I study of TAT-59 (Miproxifen), an antiestrogen developed in Japan for breast cancer, was conducted with the collaboration of 12 hospitals. A single dose of 1.25, 5, 10, 20, 40 and 80 mg, or 5 consecutive daily doses of 1.25, 5, 10, 20 and 40 mg/day, were given orally. After single dosing, no clinical adverse effects were found. Decrease of serum Na, Cl, Ca level and increase of serum LDH level were observed in one patient after a single dose of 5 mg of TAT. An increase in the serum LDH level was also observed in one patient after a single dose in the of 10 mg of TAT. An increase in the serum LDH level and total bilirubin, increase of eosinophil, K and milky serum were also observed in one patient after a single dose of 40 mg of TAT, respectively. All of these abnormal values returned to the normal level within 26 days after final administration of TAT. No adverse clinical findings nor abnormal laboratory findings were observed after consecutive administration of TAT. After postprandial single dosing, the time to reach the maximum serum concentration (Tmax) of DP-TAT, dephosphorylated metabolite of TAT, and its demethylated metabolite, DMDP, ranged from 5.0 to 7.3 hr and from 17.0 to 42.8 hr, respectively. The maximum serum concentration (Cmax) and AUC of DP and DMDP elevated in a dose-dependent manner. T1/2 of DP and DMDP ranged from 24.2 to 41.5, and from 91.9 to 214.7 hr, respectively. There were no significant differences between pharmacokinetics of TAT before and after food intake. Based on the above results, we concluded that a Phase II study should be conducted to evaluate the efficacy, safety and optimal dose of TAT.

Administration, Oral↗

PubMed1998

[A randomized controlled trial with methotrexate (MTX), 5-fluorouracil (5-FU) and pirarubicin (THP) vs 5-FU alone in advanced or recurrent gastric carcinoma. Tokai Hokuriku THP Study Group].

A randomized controlled trial was designed to investigate the therapeutic benefit of a combination chemotherapy consisting of MTX, 5-FU and THP in patients with advanced or recurrent gastric carcinoma. The patients were randomized into two groups; Group A patients (n = 37) underwent our combined chemotherapy, whereas Group B (n = 34) underwent chemotherapy with 5-FU alone as a control. There were no significant differences in various background factors between the groups. The median survival time was roughly 170 days after the randomization for the patients with advanced cancer (n = 26 for Group A and n = 25 for Group B), with no significant difference between the groups. Two long survivors, however, belonged to Group A. The median survival time of 161 days for Group A (n = 11) was longer than that of Group B (84 days, n = 9), but the difference was not statistically significant. The incidence of toxicities (leukopenia in particular) exceeding JCOG grade 3 was significantly higher for Group A, but no morbidity was observed. These results imply that patients with advanced or recurrent gastric carcinoma may benefit from a regimen of MTX, 5-FU and THP.

Aged↗

PubMed1997

Section of the vagal celiac branch in man reduces glucagon-stimulated insulin release.

The purpose of this study was to determine whether section of the celiac branch of the vagus nerve in man affects the insulin response to intravenous glucagon injection. Patients who received a subtotal gastrectomy with lymph node dissection for gastric carcinoma were divided into two groups: the celiac-preserved group (n = 16) and the celiac-sectioned group (n = 13). The hepatic branches of the vagus were preserved in both groups. The glucagon test was performed twice in each patient during the operation; before and after manipulation of the celiac branch. Blood samples were collected just before and 6 min after the injection. No difference in the mean increases in blood glucose, insulin and C-peptide levels were seen between the two groups before the nerve manipulation. In the celiac-preserved group, the glucagon stimulated glucose-related C-peptide ratio (x 10(-3) was 0.5 +/- 0.7 before the nerve manipulation and 3.5 +/- 3.0 after it, a significant difference (p < 0.01). In the celiac-sectioned group, this increase was not observed, the ratio was 0.7 +/- 0.6 before the nerve manipulation and 0.8 +/- 3.4 after. These results indicate that the vagal celiac branch in man may also be involved in the control of pancreatic insulin release.

Adult↗

PubMed1997

Hypoxia, but not reoxygenation, induces interleukin 6 gene expression through NF-kappa B activation.

Interleukin (IL) 6 is one of major mediators of inflammation, and IL-6 gene activation during hypoxia/reoxygenation has been implicated in the pathogenesis of ischemia/reperfusion injury. However, molecular events involved in IL-6 gene expression during hypoxia/reoxygenation remain to be identified. We have previously shown that NF-kappa B plays an essential and indispensable role in the transcriptional activation of the IL-6 gene induced by various stimuli, including IL-1 and tumor necrosis factor-alpha. We show here that hypoxia, but not reoxygenation, induces the activation of NF-kappa B through the degradation of a major inhibitor of NF-kappa B, I kappa B alpha. This hypoxia-induced NF-kappa B activation resulted in the kappa B-dependent transcriptional activation of the IL-6 gene. Interestingly, the time course of hypoxia-induced NF-kappa B activation was rather slow as compared with those of NF-kappa B activation induced by other stimuli, such as IL-1: a significant NF-kappa B activation was not observed before 1 hr of hypoxia treatment and persisted for up to 7 hr of hypoxia treatment. However, hypoxia-induced NF-kappa B activation was not inhibited by cycloheximide, which indicates that hypoxia directly triggers NF-kappa B activation. Furthermore, while hypoxia is unlikely to generate reactive oxygen intermediates, pretreatment of cells with antioxidants such as N-acetyl cysteine and alpha-tocopherol inhibited NF-kappa B activation induced by hypoxia. Thus, we discuss possible implications of these results for a postulated role of reactive oxygen intermediates in NF-kappa B activation.

Animals↗

PubMed1997

Extended lymph node dissection in gastrointestinal cancer.

We reviewed the literature concerning the effect of extended lymph node dissection on survival in patients with gastrointestinal cancer. Most retrospective and/or prospective nonrandomized comparative studies have claimed that extended lymph node dissection significantly improves survival rate in patients with esophageal cancer, gastric cancer, and colorectal cancer. However, it is difficult to interpret these results since specialized care provided in trials may itself improve survival. In gastric cancer, several prospective randomized trials have failed to demonstrate a survival advantage of extended dissection, while there are few well-done prospective randomized trials in esophageal or colorectal cancer. Therefore, the therapeutic value of extended lymph node dissection remains to be determined in gastrointestinal cancer. Randomized prospective studies within the bounds of the ethical treatment of patients can and should be done.

Clinical Trials as Topic↗

PubMed1997

Surgical strategy for carcinoma of the papilla of Vater on the basis of lymphatic spread and mode of recurrence.

BACKGROUND: Nodal status is one of the most important prognostic factors for carcinoma of the papilla of Vater. The pattern of lymphatic spread and mode of recurrence were analyzed by determining the frequency of nodal involvement and antemortem and postmortem examination of patients with recurrent disease. METHODS: From 1974 to 1994, 36 patients with carcinoma of papilla of Vater underwent pancreatectomy at the Kanazawa University Hospital. A precise evaluation of the nodal involvement was determined by means of careful pathologic review of the extended lymphadenectomy specimen. The mode of recurrence was determined by use of autopsy and radiographic examinations. RESULTS: Fifteen (42%) of 36 patients had nodal involvement. The lymph nodes with the highest metastatic rates were the inferior pancreaticoduodenal lymph nodes (number 13b) and the superior mesenteric lymph nodes (number 14) (13b, 31%; 14, 17%). There were no metastases in the perigastric lymph nodes. A significant relationship existed between the gross appearance of the primary tumor and nodal involvement (protruding, 22%; mixed type, 42%; ulcerative, 100%). The 5-year survival rates were 74% in the absence of nodal metastasis versus 31% with nodal metastasis. The 5-year survival rates for patients with protruding, mixed type, and ulcerative tumors were 75%, 49%, and 17%, respectively. Survival and recurrence were significantly correlated to gross appearance and nodal involvement. Retroperitoneal recurrence and liver metastasis were main modes of recurrence. CONCLUSIONS: Lymph node 13b is important in lymphatic metastasis to the superior mesenteric lymph nodes for carcinoma of papilla of Vater. Nodal dissection around the superior mesenteric artery is needed to improve the prognosis of carcinoma of papilla of Vater except in the nonexposed protruding tumor. Pylorus-preserving pancreatoduodenectomy may be indicated in patients with carcinoma of the papilla of Vater.

Adult↗

PubMed1997

Chemoprevention of DMBA-induced mammary carcinogenesis in rats by low-dose EPA and DHA.

We investigated the effects of low-dose eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on the incidence and growth of 7,12-dimethylbenz(a)anthracene (DMBA)-induced mammary carcinoma in rats fed a high-fat (HF) diet. We also examined the effects of these treatments on the fatty acid composition of tumour and serum. Tumour incidence was significantly decreased by the administration of low-dose EPA and DHA, whereas their inhibitory effects on tumour growth did not reach significance. Serum arachidonic acid (AA) level was decreased by the administration of low-dose EPA and tended to be decreased by the administration of low-dose DHA, whereas tumour AA levels were not changed. The administration of low-dose EPA and DHA may be useful for inhibiting the incidence of breast cancer.

9,10-Dimethyl-1,2-benzanthracene↗

PubMed1997

[Jejunal pouch interposition and distal gastrectomy].

We developed a new technique of reconstruction in Billroth 1 gastrectomy, jejunal pouch interposition (JPI). The interposed jejunal segment consists of a proximally double-plicated pouch and a distally isoperistaltic conduit. From 1987 to 1994, the JPI was performed on 102 patients with gastric carcinoma. The postoperative functional assay was carried out at least one year later after surgery. Sixty-five patients with the conventional Billroth 1 reconstruction (B-1) during the same period were employed as the control. Gastric emptying time estimated with scinti-scanning was significantly delayed in the JPI group compared with the B-1 group (p < 0.05). All individuals with JPI had meals three times a day whereas 13% of those with B-1 required those more than three times (p < 0.05). The incidence of dumping syndrome was significantly lower in the JPI group (6%) than the B-1 group (20%) (p < 0.05). The reflux of bile into the residual stomach was observed in the scintiscanning at 78% of patients with B-1 whereas 10% of those with JPI (p < 0.01). Endoscopy revealed that regurgitation gastritis was significantly decreased in the JPI group compared with that in the B-1 group (p < 0.01). These results suggest that the JPI prevents small stomach syndrome, dumping syndrome and alkaline reflux gastritis after the B-1 reconstruction.

Dumping Syndrome↗

PubMed1997

[Alteration of p15 and p16 gene in gastric cancer].

We analyzed p15 and p16 gene alterations in gastric cancer. Only MKN45 showed both homozygous deletions but other cell lines and all of tumor specimens did not show any alterations. Using RT-PCR analysis, decreased or no expression of the p16 gene was found in 1 of 7 cell lines (except MKN45) (14.2%) and in 8 of 20 tumors (40%), whereas no abnormalities of p15 gene expression were found. These results suggest that the p16 gene may correlate with tumorigenesis and tumor expansion due to decrease or loss of gene products in gastric cancer.

Adenocarcinoma↗

PubMed1997

[Changes in lymph node dissection for pancreatic cancer].

Two step pancreatoduodenectomy for periampullary carcinoma was first reported in 1912 by Kausch. Pancreatoduodenectomy performed for carcinoma of the head of the pancreas was first reported in 1937 by Brunschwig. Before this report, all previous pancreatoduodenectomy had been performed for other periampullary tumors. By the 1960's, pancreatoduodenectomy was performed for pancreatic cancer without lymph node dissection. However, Fortner advocated regional pancreatectomy for pancreatic cancer in 1973. In our institute, also, extended radical pancreatectomy by translateral retroperitoneal approach has been performed during the past 2 decades. Many Japanese surgeons also adopted extend pancreatectomy. In the 1980's, extended radical pancreatectomy consisted of paraaortic lymph node dissection, total pancreatectomy, and complete resection of extrapancreatic nerve plexus. However, based on the many clinicopathologic studies, pancreatoduodenectomy was better operative procedure than total pancreatectomy. Although extended radical pancreatectomy has the advantage of long-time survival, disadvantage of nutritional status and quality of life was produced by this operative procedure. Tarverso and Longmire reported new operative procedure of pylorus preserving pancreatoduodenectomy (PPPD) in 1978. Recently, this operative procedure was indicated for pancreatic cancer. However, there is a question whether PPPD is the best operative procedure for pancreatic cancer or not.

Humans↗

PubMed1997

[Perineural invasion and surgical treatment of the pancreas head cancer].

It is thought that perineural invasion by pancreatic cancer takes place either by means of direct tumor invasion of the perineural space or by means of tumor invasion through the vessels perforating the perineurium. The manner of tumor progression may be divided into four types: (1) direct progression of cancer cells into the perineural space, (2) branching at the bifurcation of the nerve fascicle, (3) perineural invasion by a probing cancer tip, and (4) invasion beyond the perineurium through defects in it. Because pancreatic cancer is often followed by severe tumor invasion of surrounding organs, major blood vessels and extrapancreatic plexus, the survival rate after the conventional pancreatoduodenectomy has been unsatisfactory. Since 1977, the author has used extended pancreatectomy with a trans-lateral retroperitoneal approach, involving resection of the portal vein, extensive excision of the retroperitoneal lymph nodes and complete resection of the pancreatic head plexus. After this surgery, 11 patients survived for more than 3 years. The five-year survival rate was 25% in case where this operation was rated as being a macroscopic curative resection.

Humans↗

PubMed1997

[Effect on 5'-deoxy-5-fluorouridine (5'-DFUR) of pyrimidine nucleoside phosphorylase (PyNPase), matrix metalloprotease and serum IAP values. Hokuriku Colorectal Cancer Chemotherapy Study Group].

PyNPase activity, MMPs activity and serum IAP values were measured in tumor tissues from colorectal cancer patients who had been divided into two groups, one given preoperative 5'-DFUR and the controls. PyNPase activity of the preoperative administration group was approximately equivalent to that of the controls. In the control group, correlations were assessed between PyNPase activity and activities of MMP1 and MMP3. To assess the effect of 5'-DFUR on the activity of MMPs, we divided patients into two groups, a high and a low PyNPase activity group. Although there was no correlation with MMPs activity of the preoperative administration group and the control group in the low PyNPase activity group, the activities of MMP1 and MMP9 of the control group were significantly higher in the high PyNPase activity group. Moreover, the serum IAP value of the administration group was significantly lower than that of the control group. These results indicated that PyNPase activity was thus suggested to be somehow related to MMPs activity and serum IAP values.

Adult↗

PubMed1996

Lymphatic flow and neural plexus invasion associated with carcinoma of the body and tail of the pancreas.

BACKGROUND: Lymph node status and neural plexus invasion are the most important prognostic factors that may be amenable to surgery for carcinoma of the body and tail of the pancreas. The pattern of lymphatic spread and neural plexus invasion were evaluated by analysis of various clinicopathologic factors. METHODS: Twenty patients with carcinoma of the body and tail of the pancreas underwent pancreatectomy with systemic regional lymph node dissection at Kanazawa University Hospital. A precise evaluation of their lymph node involvement and neural plexus invasion was determined. RESULTS: Sixteen of 20 patients (80%) had lymph node involvement. The lymph nodes with a high metastatic rate were those along the splenic artery (50%), the inferior body lymph nodes (35%), the lymph nodes around the common hepatic artery (25%), and the paraaortic lymph nodes (20%). There was no relationship between tumor size, histologic type, and lymph node involvement. Plexus invasion was observed in 14 patients (70%). The most frequent site was the splenic plexus, but between 15% and 20% of the patients had celiac or superior mesenteric plexus invasion. There was no relationship between tumor size, histologic type, and neural plexus invasion. CONCLUSIONS: Based on these results, extended lymphadenectomy including the paraaortic lymph nodes, celiac lymph nodes, and superior mesenteric lymph nodes may improve the prognosis for patients with carcinoma of the body and tail of the pancreas. Extrapancreatic neural plexus dissection, especially of the celiac plexus and superior mesenteric plexus, also is necessary.

Adenocarcinoma↗

PubMed1996

Reflux of duodenal or gastro-duodenal contents induces esophageal carcinoma in rats.

Esophageal adenocarcinoma arises from Barrett's esophagus, which is induced by gastro-esophageal reflux. This refluxate often contains duodenal contents, whose backflow triggers gastric carcinoma, suggesting the hypothesis that refluxed duodenal contents cause esophageal carcinoma. This study examines the role of duodenal and gastric reflux in the absence of exogenous carcinogens in esophageal carcinogenesis. Wistar male rats, 120 in all, each weighing approximately 250 g, were used. Three experimental procedures were performed to produce gastro-duodeno-esophageal reflux, duodeno-esophageal reflux and gastro-esophageal reflux, for comparison with 2 control procedures, Roux-en-Y reconstruction and a sham operation. The animals were fed a standard diet and were examined 50 weeks after surgery. While no carcinoma was found among the 16 gastro-esophageal-reflux, 11 Roux-en-Y and 12 sham-operation animals, 10 of the 12 animals with gastro-duodeno-esophageal reflux (83%) and 10 of the 13 with duodeno-esophageal reflux (77%) developed esophageal carcinoma. The difference between groups was significant (p < 0.001). Two animals with gastro-duodeno-esophageal reflux had esophageal double and triple carcinomas respectively. Of the 23 carcinomas, 16 were adenocarcinoma, 4 adenosquamous carcinoma, and 3 squamous-cell carcinoma. Adenocarcinoma developed from the columnar-lined epithelium near the esophago-jejunostoma, while adenosquamous and squamous-cell carcinoma arose from the squamous esophagitis. These observations demonstrate that refluxed duodenal contents per so are responsible for esophageal carcinogenesis.

Adenocarcinoma↗

PubMed1996

Immunosuppressant FK506 induces interleukin-6 production through the activation of transcription factor nuclear factor (NF)-kappa(B). Implications for FK506 nephropathy.

FK506 is a powerful immunosuppressive drug currently in use that inhibits the activation of several transcription factors (nuclear factor (NF)-AT and NF-kappaB) critical for T cell activation. We show here that, contrary to the situation in T cells, FK506 activates transcription factor NF-kappaB in nonlymphoid cells such as fibroblasts and renal mesangial cells. We further show that FK506 induces NF-kappaB-regulated IL-6 production in vitro and in vivo, in particular in kidney. IL-6 has been shown previously to produce renal abnormalities in vivo, such as mesangioproliferative glomerulonephritis. Similar renal abnormalities were also observed in FK506-treated animals. These results thus suggest a causal relationship between FK506-induced NF-kappaB activation/IL-6 production and some of FK506-induced renal abnormalities.

Animals↗