PubMed Health⌕ Search

Biomedical subjects

A Tsuchida

Publications and source records attributed to A Tsuchida.

At least 55 records · Page 3Linked to original sources
PubMed2000

Delayed onset of pulmonary hypertension associated with an appetite suppressant, mazindol: a case report.

The use of the appetite suppressant agents aminorex and fenfluramine derivatives has been reported as a risk factor for the development of pulmonary hypertension. A 29-year-old female developed pulmonary hypertension suspected to be due to an amphetamine-like appetite suppressant agent, mazindol ((+/-)-5-(p-chlorophenyl)-2,5-dihydro-3H-imidazo [2,1-a] isoindol-5-ol). She was admitted to Sapporo Medical University Hospital with dyspnea due to severe pulmonary hypertension. Twelve months prior to admission, she had taken mazindol continuously for a period of 10 weeks. As yet, her pulmonary hypertension has not completely improved. This is the first reported case of mazindol-associated pulmonary hypertension, which developed after a long latent interval, and it suggests that mazindol is also a risk factor for the development of pulmonary hypertension, making long-term follow-up necessary for patients taking this anorectic agent.

Adult↗
PubMed2000

Endothelium-dependent coronary response is impaired in the myocardium at an early phase of post-infarct remodeling.

The aim of the present study was to characterize endothelium-dependent and -independent coronary functions in remodeling hearts after infarction. First, echocardiography showed that the left ventricular diastolic dimension and thickness of the non-ischemic region were increased by 25% and 20%, respectively, at 2 weeks after coronary ligation in the rabbit heart. In the second series of experiments, 2 weeks after coronary ligation or a sham operation, the heart was isolated and perfused with modified Krebs-Henseleit buffer at 75 mmHg, and effluent from the pulmonary artery was measured as total coronary flow (CF). Regional CF analysis by microspheres indicated that flow to the infarcted region as a percentage of total CF is negligibly small. There was no significant difference between CF responses to sodium nitroprusside (10(-9)-10(-5) mole/l) in the sham-operated and remodeling hearts. However, the increase in CF after acetylcholine (ACh: 10(-8)-10(-5) mole/l) injection was significantly reduced by approximately 50% in the remodeling hearts compared to that in the sham-operated hearts. Furthermore, the percent increase in CF by ACh (10(-5) mole/l) was inversely correlated with weight of the remodeling myocardium (r = -0.630, p < 0.05). These results suggest that endothelium-dependent vasodilatory function is impaired in the myocardium at the early stage of post-infarct remodeling and that this endothelial dysfunction is closely related to the degree of hypertrophy of the remodeling myocardium.

Acetylcholine↗
PubMed2000

Brain-derived neurotrophic factor regulates glucose metabolism by modulating energy balance in diabetic mice.

We previously reported that brain-derived neurotrophic factor (BDNF) regulates both food intake and blood glucose metabolism in rodent obese diabetic models such as C57BL/KsJ-lepr(db)/lepr(db) (db/db) mice. To elucidate the effect of BDNF on glucose metabolism, we designed a novel pellet pair-feeding apparatus to eliminate the effect of appetite alteration on glucose metabolism. The apparatus was used to synchronize food intake precisely between BDNF-treated and vehicle-treated db/db mice. It was shown using this pellet pair-feeding apparatus that BDNF administered daily (20 mg x kg(-1) x day(-1)) to db/db mice significantly lowered blood glucose compared with pellet pair-fed db/db mice. To evaluate the effect of BDNF on insulin action, we used streptozotocin-induced type 1 diabetic mice. In this case, BDNF did not lower blood glucose concentration but rather enhanced the hypoglycemic action of insulin. In hyperglycemic db/db mice, pancreatic insulin content was reduced and glucagon content was increased compared with normoglycemic db/m mice. BDNF administered to db/db mice significantly restored both pancreatic insulin and glucagon content. Histological observations of aldehyde-fuchsin staining and immunostaining with anti-insulin indicated that insulin-positive pancreatic beta-cells were extensively regranulated by BDNF administration. We also studied the effect of BDNF on KK mice, normoglycemic animals with impaired glucose tolerance. In these mice, BDNF administration improved insulin resistance in the oral glucose tolerance test. To elucidate how blood glucose was metabolized in BDNF-treated animals, we investigated the effect of BDNF on the energy metabolism of db/db mice. Body temperature and oxygen consumption of the pellet pair-fed vehicle-treated mice were remarkably lower than the ad libitum-fed vehicle-treated mice. Daily BDNF administration for 3 weeks completely ameliorated both of the reductions. Finally, to clarify its action mechanism, the effect of intracerebroventricular administration of BDNF on db/db mice was examined. Here, a small dose of BDNF was found to be effective in lowering blood glucose concentration. This indicates that BDNF regulates glucose metabolism by acting directly on the brain.

Animals↗
PubMed2000

A case of eosinophilic pleural effusion induced by pancreatothoracic fistula.

A 49-year-old man was admitted for evaluation of a left pleural effusion. Thoracenthesis yielded a hemorrhagic pleural effusion with a high percentage of eosinophils (15.9%). Although there were no significant abdominal signs, serological examinations demonstrated a marked increase of pancreatic enzyme activity. Moreover, abdominal CT demonstrated cystic changes between the tail of the pancreas and the spleen. Accordingly ERP was performed under pressure, and contrast medium draining from the pancreas was observed. Pancreatic pleural effusion in this patient consisted of pancreatic juice retained in the thoracic cavity, which resulted from intrapancreatic fistulation connecting to the thoracic cavity due to a pancreatic cyst caused by chronic pancreatitis. The present report indicates that we should investigate the retention of eosinophilic pleural effusion considering not only the possibility of thoracic disease, but also the possibility of a pleural effusion derived from abdominal diseases.

Eosinophilia↗
PubMed1999

Malignant paraganglioma metachronously recurring at short duration in different paraganglions: report of a case.

We report the rare case of a 57-year-old man with retroperitoneal malignant paraganglioma. He was referred to our hospital complaining of left lower abdominal dull pain. Computer tomography (CT), magnetic resonance imaging, and aortography showed a mass measuring 5 x 4 cm in size on the left side of the abdominal aorta below the renal artery. The resected tumor was confirmed histologically to be malignant paraganglioma. Irradiation of the resected area was performed. Four months after the operation, an abdominal CT scan showed a 5.5 x 3.0 cm mass on the right side of the aorta below the diaphragm. This tumor was thereafter also resected. Three months after the second operation, a soft subcutaneous nodule measuring 4.5 x 2.0 cm in size was palpable above the left clavicle and was visible on a CT scan. A resection was again performed. All tumors showed the same histological findings. This is the first case reported in the Japanese literature with such a short-term demonstration of multiple metachronous recurrences in different paraganglions.

Humans↗
PubMed1999

Pancreatic arteriovenous malformation observed to bleed from the bile duct and a duodenal ulcer: report of a case.

A 48-year-old man with recurrent episodes of biliary colic and subsequent pancreatitis was admitted to undergo a cholecystectomy. A gastroduodenal fiberscopic examination was performed because of massive melena on the seventh day after admission. It revealed a shallow ulcer on the posterior wall of a duodenal bulbus with rubor and an exposed vessel, which was clipped endoscopically to stop the bleeding. Further observations showed the papilla of Vater to be bleeding from the papilla. A contrast-enhanced abdominal computed tomography scan demonstrated a dilatation of the common bile duct and several dilated vasculatures around the portal vein, some of which drained into the portal vein. Based on the angiography findings, a diagnosis of arteriovenous malformation in the pancreas head was obtained and an embolization of the gastroduodenal artery was performed. Although the melena subsided, he underwent a pylorus-preserving pancreatoduodenectomy to prevent the recurrence of hemorrhaging. The histopathological findings of the bile duct revealed inflammatory cell infiltration and a detachment of the epithelium, except in a small part of the bile duct. A rupture of a damaged vessel inside the bile duct was observed, which was thought to be the cause of hemobilia. Sections of the pancreatic head demonstrated an inflammatory lesion with fibrosis and saponification as well as a large degree of arteriovenous anastomosis. The patient was discharged on the 35th day after the operation following an uneventful postoperative course.

Arteriovenous Malformations↗
PubMed1999

Reperfusion arrhythmias in the murine heart: their characteristics and alteration after ischemic preconditioning.

In this study, we examined the features of reperfusion arrhythmias and the effect of preconditioning (PC) in the mouse for future application of genetically engineered mice to study mechanisms of this type of arrhythmia. Under pentobarbital anesthesia, reperfusion arrhythmias were induced by temporary occlusion of the left anterior descending coronary artery and reperfusion in BALB/c AJc1 mice. In the first protocol, the coronary artery was occluded for periods ranging from 2 to 15 min and then reperfused. In the second protocol, hearts were preconditioned with 2- or 3-min ischemia and 5-min reperfusion prior to the 5 min of coronary occlusion. An electrocardiogram was recorded throughout the experiment, and arrhythmias were diagnosed according to the Lambeth Convention criteria. The incidences of reperfusion-induced ventricular tachycardia (VT) in hearts that received 2, 3, 5, 10 and 15-min ischemia (n = 10 approximately 14) were 0, 9, 73, 55 and 30 %, respectively. Ventricular fibrillation (VF) was not observed upon reperfusion regardless of the ischemia duration. PC with 2-min ischemia and with 3-min ischemia (n = 10 for each PC) reduced the incidences of reperfusion VT after 5-min ischemia to 40% and 10%, respectively. However, in mice that developed reperfusion VT, the VT duration was similar to that in non-preconditioned controls, ranging from 1 to 16 s. These results suggest that the relationship between ischemia duration and incidence of VT upon subsequent reperfusion is "bell shaped" and that PC has anti-arrhythmic effects in the mouse, as it does in anesthetized rat hearts. However, there appear to be differences in the incidence of reperfusion-induced VF and the duration of reperfusion VT between these species. Thus, the present murine preparation appears to be a useful model for studying the mechanism of reperfusion VT and PC, though it does not share all of the features of reperfusion arrhythmias with the anesthetized rat preparation.

Animals↗
PubMed1999

Cellular kinetics and gene mutations in gallbladder mucosa with an anomalous junction of pancreaticobiliary duct.

Anomalous junction of the pancreaticobiliary duct (AJPBD) is thought to be an important risk factor for gallbladder carcinoma in Japan. We have reported the characteristic pathology, cellular kinetics, and gene mutations to clarify the mechanism of carcinogenesis in gallbladder mucosa with AJPBD. A comprehensive review of the literature was undertaken, with referencing of major articles on the subject. A sequence of hyperplastic changes, with a corresponding increase in cellular kinetics with progression through dysplasia to carcinoma is important in carcinogenesis of gallbladder mucosa with AJPBD. p53 mutations may contribute to the transition from premalignancy to malignancy in the early stage of carcinogenesis of the gallbladder mucosa, regardless of the presence of AJPBD. The specific mutation of GGT-to-GAT in codon 12 of K-ras may play an important role in carcinogenesis of gallbladder mucosa with AJPBD.

Adenocarcinoma↗
PubMed1999

Chronic treatment with an ACE inhibitor, temocapril, lowers the threshold for the infarct size-limiting effect of ischemic preconditioning.

This study examined whether chronic inhibition of the angiotensin-converting enzyme (ACE) lowers the threshold of preconditioning (PC) and potentiates cardio-protection of subthreshold PC. Rabbits were orally administered either 0.5 mg/kg/day temocapril or placebo for 14 days and were randomly subjected to subthreshold PC (i.e., PC with 2 minutes ischemia/5 minutes reperfusion) or no PC before a 30-minute coronary artery occlusion and a 3-hour reperfusion. The size of the infarct was determined by tetrazolium staining and was expressed as the percent of the area at risk (%IS/AR). At the end of the experiment, the lungs were sampled for a tissue ACE activity assay. There was no significant difference in %IS/AR among the rabbits given placebo alone, placebo plus 2 minutes PC, and temocapril alone (%IS/AR = 59.5 +/- 5.8%, 43.6 +/- 3.7%, and 56.7 +/- 7.1%, respectively). However, %IS/AR was significantly reduced in the group that received temocapril and 2 minutes PC before infarction (%IS/AR = 35.4 +/- 4.8%, P < 0.05 vs. placebo control and temocapril control). The lung tissue ACE activity did not differ in the placebo-treated rabbits with and without PC (12.6 +/- 2.8 vs. 13.7 +/- 2.0 nmol/g protein/min) but was suppressed in temocapril-treated rabbits despite 2 minutes PC (0.9 +/- 0.1 vs. 1.5 +/- 0.2 nmol/g protein/min, both P < 0.05 vs. placebo-treated groups). The present results suggest that chronic inhibition of ACE is beneficial for potentiating the anti-infarct effect of subthreshold PC.

Administration, Oral↗
PubMed1999

Adenosine and preconditioning revisited.

1. Myocardial tolerance against infarction is substantially increased by exposing myocytes to 3-10 min transient ischaemia. In this phenomenon, termed 'preconditioning', the adenosine receptor is one of the redundant triggers and the best characterized factor in the cardioprotective mechanism. 2. An increase in interstitial adenosine during preconditioning is thought to be derived primarily from hydrolysis of 5'-AMP in the myocyte by cytosolic 5'-nucleotidase, although a contribution of ectosolic 5'-nucleotidase remains controversial. Adenosine production during ischaemia is substantially suppressed in the preconditioned myocardium, probably due to a decrease in ATP utilization. 3. The adenosine receptor needs to be activated not only at the time of preconditioning ischemia, but also during ischaemic insult for the preconditioning to be cardioprotective. However, the extent of cardioprotection afforded by preconditioning is primarily determined by the interstitial adenosine level achieved during preconditioning ischaemia, not by the level during sustained ischaemia. These data suggest that a post-receptor mechanism downstream of the adenosine receptor may be up-regulated after preconditioning. 4. Studies in vitro suggest that the subtypes of adenosine receptor relevant to preconditioning against infarction are A1 and A3, the activation of which appears to provide additive protection. The functional interrelationship between these subtypes in vivo remains unknown. 5. An important step downstream of adenosine receptor activation is protein kinase C (PKC), which facilitates opening of ATP-sensitive potassium (KATP) channels, probably leading to enhancement of myocardial tolerance. However, activation of other protein kinases, such as tyrosine kinase, may also be important in preconditioning, depending on the animal species and preconditioning protocols. The PKC isoform and location of KATP channels (i.e. sarcolemmal vs mitochondrial KATP) that induce anti-infarct tolerance in myocytes remain to be identified.

Adenosine↗
PubMed1999

Using sector endoluminal ultrasound to identify the normal pancreas when axial computed tomography is falsely positive.

RATIONALE AND OBJECTIVES: Little has been reported on the ability of endoluminal ultrasound (EUS) to identify a normal pancreas after an abnormal axial computed tomogram (CT). Many clinicians still use axial technology, as opposed to helical or spiral CT, which differ in scanning speed. Spiral CT and EUS are considered equal in their ability to diagnose pancreatic tumors. Although this is not the case with axial CT, the complementary role by EUS has not been defined. This study reports on the ability of EUS to identify the "true-negative" pancreas deemed abnormal by axial CT. METHODS: Sixty-five consecutive patients suspected of having a small pancreatic lesion were studied by comparing axial CT and EUS examinations, using each patient as his or her own control. Identification of a normal pancreas was reviewed using surgery, biopsy, and long-term clinical follow-up as the standard of truth. RESULTS: Thirty-three patients were documented as having small pancreatic lesions; the remaining 32 were normal. The sensitivity and specificity, respectively, were 91% and 41% for axial CT and 88% and 88% for EUS. The positive and negative predictive values, respectively, were 61% and 82% for CT and 88% and 88% for EUS. The statistical differences between axial CT and EUS were significant. CONCLUSION: An axial CT positive for a small pancreatic mass requires confirmation with additional imaging before invasive management. The specificity of EUS--twice that of CT--is strong evidence that EUS can fulfill this role. Review of the literature supports the conclusion that EUS should be required in the workup of small pancreatic lesions identified at axial CT.

Chronic Disease↗
PubMed1999

Gene mutations of K-ras in gallbladder mucosae and gallbladder carcinoma with an anomalous junction of the pancreaticobiliary duct.

OBJECTIVE: In this study, we examined the mutational spectrum of K-ras in cases of gallbladder and gallbladder carcinoma with an anomalous junction of the pancreaticobiliary duct (AJPBD). METHODS: We examined 35 gallbladders with AJPBD (20 with hyperplasia, 15 with carcinoma) and 38 gallbladders without AJPBD (four normal gallbladders, four with hyperplasia, six with adenoma, 24 with carcinoma). Polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) and direct sequencing were performed to detect mutations in codon 12 or 13 of K-ras. RESULTS: In the cases with AJPBD, the prevalences of K-ras mutation were 15% (3/20) in hyperplasia, 60% (6/10) in stage I carcinoma, and 100% (5/5) in stage II-IV carcinoma. In the cases without AJPBD, the prevalences of K-ras mutation were 0% (0/4) in normal gallbladder, 0% (0/4) in hyperplasia, 17% (1/6) in adenoma, 7% (1/16) in stage I carcinoma, and 38% (3/8) in stage II-IV carcinoma. Prevalences of K-ras mutation in hyperplasia and carcinoma with AJPBD were greater than those without AJPBD (p < 0.05). The point mutation of GGT to GAT in codon 12 was frequently observed in the cases with AJPBD. CONCLUSION: These results suggest that the specific K-ras mutation in codon 12 (GGT to GAT) may contribute to the early stage of carcinogenesis in the gallbladder with AJPBD.

Adenoma↗
PubMed1999

Cholecystokinin regulates the invasiveness of human pancreatic cancer cell lines via protein kinase C pathway.

We have previously reported that cholecystokinin (CCK) plays an important role in the invasiveness and the production of matrix metalloproteinase-9 (MMP-9) in two human pancreatic cancer cell lines. In this study we investigated the pathway of the invasiveness associated with MMP-9 of those lines regulated by CCK. Two human pancreatic cancer cell lines were treated with CCK-8 alone, CCK-8 and staurosporine, or CCK-8 and indomethacine. The invasiveness and the production of MMP-9 were decreased with staurosporine but not indomethacine. These results suggest that CCK may regulate the invasiveness and the production of MMP-9 via protein kinase C in human pancreatic cancer cell lines.

Blotting, Western↗
PubMed1999

[Effects of speed of injection on anesthesia induction with propofol and fentanyl].

We examined the effects of injection rate of propofol on injection pain and postinduction hypotension and bradycardia when fentanyl was administrated before propofol. Fifty-five patients premedicated with midazolam and atropine were randomly allocated to two groups. Three minutes after administration of fentanyl 100 micrograms, propofol 1.5 mg.kg-1 was injected to a forearm vein at a rate of 800 ml.hr-1 in Group FS or 1 ml.s-1 in Group FR. Anesthesia was maintained with 67% nitrous oxide in oxygen and supplemental propofol infusion. The incidence and severity of pain on injection were not influenced with injection speed. The rapid rate of injection significantly shortened the induction time. The decrease in systolic and diastolic blood pressures and heart rate after induction were not affected by injection speed. In conclusion, rapid injection of propofol after fentanyl was effective to shorten the induction time without increasing the postinduction hypotension and bradycardia.

Aged↗
PubMed1999

[Effects of the bolus injection rate on anesthesia induction with propofol].

We examined the influence of the bolus injection rate of propofol on the cardiovascular depression and injection pain. Fifty-one patients of ASA grade 1 or 2 were randomly allocated to two groups. After premedication with midazolam 0.06 mg.kg-1 and atropine 0.006 mg.kg-1 i.m., propofol 2 mg.kg-1 was injected to a forearm vein at a rate of 800 ml.hr-1 in Group A or 1 ml.s-1 in Group B. Anesthesia was maintained thereafter with 67% nitrous oxide in oxygen and propofol infused at 6 mg.kg-1.hr-1. The incidence and severity of pain on injection were lower in Group B compared with Group A, but the difference was not statistically significant. The induction time was significantly shorter in Group B than in Group A (40 vs. 73 sec: P < 0.01). There were no significant differences between the two injection rates in peak reductions in systolic and diastolic blood pressure and heart rate. In conclusion, rapid injection of propofol was effective to shorten the induction time without any adverse effects.

Adolescent↗
PubMed1999

[Percutaneous ethanol injection therapy with hepatic arterial infusion chemotherapy for liver metastases from gastric cancer].

Ten patients with liver metastases from advanced gastric cancer received percutaneous ethanol injection therapy (PEI) and chemotherapy by hepatic arterial infusion (HAI) via implantable reservoir. A 90% ethanol solution including 10%. Lipiodol was injected in the liver as PEI.5-FU, EPIR and MMC were used as the regimen for HAI chemotherapy. We have performed this therapy (PEI + HAI) for ten patients with liver metastases since February, 1997. These patients have received this therapy for 4-36 months and three patients died within 16 months. However, three patients did not develop any liver failure after this therapy. The median survival rate was 25.2 months. There are statistically significant differences between upto ss and over se of invasion, and between INF alpha and gamma (p = 0.005).

Aged↗
PubMed1998

Electro-optic Properties of Colloidal Crystals As Studied by Reflection Spectroscopy.

Electro-optic properties of colloidal crystals of silica spheres in the exhaustively deionized aqueous suspension have been studied by the reflection spectroscopy using a T-type cell. Acoustic shear waves are induced when sine-wave electric fields ranging from 0.01 to 1 Hz are applied. Modulation effects of the crystals on the applied AC fields such as phase delay, change in response intensity, waveform transformation, and harmonics generation are observed. The shear waves propagate outside the electrodes where the electric field is absent. The synchronous fluctuation of the colloidal spheres including expanded electrical double layers in the crystal lattice will be one of the main causes of the electro-optic nature of the crystals. Copyright 1998 Academic Press.

Journal Article↗