Biomedical subjects

H Yamauchi

Publications and source records attributed to H Yamauchi.

At least 109 records · Page 6Linked to original sources

PubMed1999

Morphological and immunohistochemical changes in intestinal mucosa and PYY release following total colectomy with ileal pouch-anal anastomosis in dogs.

Other studies have shown that both morphological and functional adaptation occur in the ileal mucosa after total colectomy and may be mediated by humoral factors. To elucidate the participation of peptide YY (PYY) in intestinal adaptation after total proctocolectomy with ileal pouch-anal anastomosis (IPAA), changes in the number of PYY-containing cells and in histological appearance in the intestinal mucosa, especially in the mucosa of ileal pouch, were investigated in dogs. We further examined changes in postprandial PYY release in relation to those in PYY-containing cells. Ten adult beagle dogs underwent IPAA. Before and 2, 6, and 12 months after surgery, a test meal was given, and blood samples were taken from a foreleg vein at intervals for 3 hr for measurements of plasma PYY concentration by radioimmunoassay. Before and one year after surgery, morphological studies of the intestinal mucosa were performed using parameters such as villous height (VH), mucosal thickness (MT), and villous index (VI). Immunohistochemical studies of PYY were also done in the intestinal mucosa. Both fasting and postprandial plasma PYY levels were reduced to half of the preoperative levels at two months after surgery. Thereafter, postprandial levels approached preoperative concentrations, while fasting levels remained unchanged. VH, MT, and VI were significantly smaller in the ileal pouch than in the ileal end of the controls. The MT of the ileal pouch was similar to that of the colon. PYY-containing cells in the mucosa of the ileal pouch were distributed more densely than those in the ileal end, similar to those in the colon of the controls. It was concluded that after IPAA, the pouch mucosa gradually changed to resemble the colonic mucosa not only in histological appearance but also in the population of PYY-containing cells. It is therefore considered that colonic transformation of the ileal-pouch mucosa is closely related to the increase in the number of PYY-containing cells and the steady recovery of postprandial PYY secretion.

Animals↗

PubMed1999

Early gastric cancer in the young: clinicopathological study.

BACKGROUND: Thirty-four cases of early gastric carcinoma in patients under 50 years of age treated in the period from 1985 to 1995 were reviewed. METHODS: These constituted 3.7% of 923 cases of gastric cancer in patients of all ages that were treated at Sendai National Hospital during the same 10-year period. Data were compared with those of 194 patients 50 years of age or older. RESULTS: The incidence of gastric cancer in men and women was almost the same in both groups. Tumours tended to be located distally in the stomach. Macroscopically, depressed lesions were more common in younger patients. Significant differences were observed in depth of invasion, histological type and histological growth patterns. CONCLUSIONS: The distinctive histological features of early gastric cancer in younger patients were a diffuse type of cancer with infiltrative tumours in the mucosal layer. The prognosis of younger patients was similar to that of older patients.

Adult↗

PubMed1999

Selective cerebral hematocrit decrease in the centrum semiovale after carotid artery occlusion: a PET study.

The centrum semiovale may be susceptible to hypoperfusion as a result of carotid artery occlusion. Recent studies suggest that the cerebral hematocrit decreases with diminished cerebral perfusion pressure. To investigate whether the effect of carotid artery occlusion on the hematocrit in the centrum semiovale is different from that in the cerebral cortex, seven patients with unilateral carotid artery occlusion were studied with positron emission tomography. The distributions of the red blood cell and plasma volumes were assessed using carbon monoxide labeled with oxygen 15 and human serum albumin-dithiosemicarbazone tracers labeled with copper 62, respectively. The CBF and CMRO2 were also measured with the (15)O steady-state technique. The calculated values for the hematocrit in the centrum semiovale ipsilateral to the arterial occlusion were significantly decreased compared with those in any of the other regions examined (the overlying cortical region and the contralateral cortex and centrum semiovale). This decrease in hematocrit, which resulted from a more pronounced increase in plasma volume than in red blood cell volume, was associated with a decrease in CBF and an increase in the oxygen extraction fraction. Hemodynamic disturbance caused by carotid artery occlusion may induce selective decrease of hematocrit limited to the centrum semiovale.

Aged↗

PubMed1999

Uncoupling of oxygen and glucose metabolism in persistent crossed cerebellar diaschisis.

BACKGROUND AND PURPOSE: The pathophysiology of deafferentation-induced changes after stroke remains unclear. Some supratentorial strokes cause persistent decreases in blood flow and metabolism in the contralateral cerebellum (persistent crossed cerebellar diaschisis[CCD]). Our previous study showed uncoupling of oxygen consumption and blood flow in this condition, which may reflect a characteristic change in brain metabolism caused by deafferentation. This uncoupling might be related to oxidation of some substrates other than blood-borne glucose, which could also lead to the uncoupling of oxygen consumption and glucose utilization. The purpose of this study was to investigate whether oxygen consumption is uncoupled from glucose utilization in persistent CCD. METHODS: Using positron emission tomography in 10 unilateral supratentorial stroke patients, we evaluated regional blood flow, oxygen consumption, and glucose utilization in the cerebellar cortex in the chronic stage. Eight patients with a significant cerebellar blood flow asymmetry, defined as outside the 95% confidence limits predefined in 9 normal subjects, were selected as patients with persistent CCD. RESULTS: In patients with CCD, the cerebellar cortex contralateral to the stroke showed significant decreases in both oxygen consumption and glucose utilization compared with the ipsilateral cerebellar cortex. The decrease in oxygen consumption was less than the decrease in glucose utilization, resulting in a significant increase in the oxygen consumption/glucose utilization ratio. CONCLUSIONS: Persistent CCD caused by stroke may induce uncoupling of oxygen consumption and glucose utilization, which may reflect a characteristic change in brain metabolism caused by deafferentation.

Aged↗

PubMed1999

A decrease in regional cerebral blood volume and hematocrit in crossed cerebellar diaschisis.

BACKGROUND AND PURPOSE: The pathophysiology of crossed cerebellar diaschisis (CCD) remains to be elucidated. In CCD, the metabolic suppression resulting from deafferentation may cause vasoconstriction, which may result in a decrease in cerebral blood volume (CBV) and may differentially affect the flows of red blood cells and of plasma. The purpose of this study was to investigate whether CCD decreases the total CBV (cerebral red blood cell volume [CRCV] plus cerebral plasma volume [CPV]) and, if so, whether CCD differentially affects the CRCV and CPV, resulting in a change in hematocrit. METHODS: We used positron emission tomography to study 7 patients with a unilateral supratentorial infarct and CCD. The distributions of CRCV and CPV were assessed by using 15O-labeled carbon monoxide and 62Cu-labeled human serum albumin-dithiosemicarbazone tracers, respectively. The CRCV, CPV, and calculated hematocrit values were compared between the cerebellar hemispheres. RESULTS: In the cerebellar cortex contralateral to the supratentorial infarct, the values of CRCV, CPV, and total CBV were significantly decreased compared with those in the ipsilateral cerebellar cortex. The CRCV was decreased to a greater degree than the CPV, and the value of the hematocrit was decreased in the contralateral cerebellar cortex. CONCLUSIONS: CCD may decrease the total CBV, which may reflect vasoconstriction caused by decreased metabolism due to deafferentation. In addition, the more pronounced decrease in CRCV than in CPV may result in a decrease in hematocrit in CCD.

Aged↗

PubMed1999

Modified Fontan operation. Considerations for the determination of the appropriate procedure.

BACKGROUND: Although the surgical results of the modified Fontan operation continues to improve, there are various advantages and disadvantages in terms of the post operative condition associated with the Fontan modifications. Late morbidity and mortality are mainly due to arrhythmias, thromboembolic complications, systemic venous hypertension and infective endocarditis. We reported our experience of the modified Fontan operation to determine an appropriate procedure for each patient. METHODS AND RESULTS: Seven patients (ranging from the age 1-14 years) underwent a modified Fontan operation including a lateral tunnel (n = 1), extracardiac conduit (n = 2) and autogenous atrial tunnel (n = 4). There was one hospital death due to sepsis in which the patient underwent lateral tunnel procedure. The mean follow up of another six patients was 20 months (ranging from 1-39 months) and all patients were classified as NYHA class I, and remained in normal sinus rhythm without any thromboembolic complications. CONCLUSIONS: When using the autogenous atrial tunnel, there are potential advantages; it is not associated with thromboembolism or endocarditis and has growth potential. However, in high-risk patients with increased pulmonary vascular resistance, impaired ventricular function and pre-operative atrial arrhythmias, it appears reasonable to use an extracardiac conduit.

Adolescent↗

PubMed1999

Emergency abdominal surgery for small bowel perforation secondary to metastatic lung cancer.

Emergency surgery for bowel perforation caused by metastases from lung cancer is rare. Two cases of small bowel perforation due to metastasizing lung cancer are reported. Both patients were admitted as a surgical emergency case. One of the two patients presented herein survived and was discharged from the hospital. Perforated small bowel due to metastatic lung cancer is a highly fatal event that occurs in the late phases of the disease. Despite the poor prognosis, early and appropriate therapy will occasionally yield successful surgical palliation. Patients with known lung cancer who develop abdominal complaints should be examined thoroughly and treated quickly.

Adenocarcinoma↗

PubMed1999

An attribution-emotion model of helping behavior.

To investigate the help-giving judgment of the attribution-emotion model further, data from five manifest variables of controllability, responsibility, anger, sympathy, and help-giving, were subjected to path analysis, which provided an easy interpretation of the model. Participants were 90 men and 81 women in an introductory psychology course.

Adult↗

PubMed1999

Perceived control, autonomy, and self-regulated learning strategies among Japanese high school students.

This study investigated relations among measures of perceived control, autonomy, and self-regulated learning strategies for 228 junior high school (90 in Grade 7 and 138 in Grade 8) and 306 senior high school (184 in Grade 11 and 122 in Grade 12) students. Participants completed three self-report questionnaires designed to measure control beliefs, strategy beliefs, capacity beliefs, seven types of motivation, and two types of self-regulated strategies. Confirmatory factor analysis identified the structure of perceived control modeled by Skinner, Chapman, and Baltes (1988), the seven-factor structure of autonomy by Vallerand, Pelletier, Blais, Briere, Senecal, and Vallieres (1992, 1993), and the two types of self-regulated learning strategies by Pintrich and De Groot (1990). Significant "grade" differences were obtained in several measures. Canonical correlation was used to investigate the relations between perceived control and autonomy measures. Finally, multiple regression analysis was used to investigate the relations between perceived control and self-regulated learning strategies and between autonomy and self-regulated learning strategies. Implications of the results are presented.

Adolescent↗

PubMed1999

Poorly differentiated, solid-type adenocarcinoma of the stomach.

Data of 58 cases of poorly differentiated, solid-type adenocarcinoma of the stomach treated at our hospital between 1985 and 1995 were reviewed and compared to data of 146 cases of non-solid-type carcinoma in order to determine whether there are distinguishable clinicopathological features between these two types of carcinoma. Significant differences were observed with respect to tumor size, stage, macroscopic appearance, depth of invasion, histologic growth pattern, lymph node metastasis, microscopical lymphatic invasion and vascular permeation. Patients in the solid-type cancer group tended to have smaller tumors; the disease was in the early stage in 48% of the patients, and total gastrectomy was performed in only 20 of the 58 patients. Nodal involvement, lymphatic invasion and vascular permeation were also less common in patients with solid-type cancer. The overall survival rate of patients with solid-type carcinoma was higher than that of patients with non-solid-type carcinoma, though no significant differences were observed when corrected for stage. Our results suggest that poorly differentiated solid-type carcinoma of the stomach should be regarded as a distinct type of adenocarcinoma that has a good prognosis. The significant prognostic factors for this type of gastric cancer are lymphatic invasion and tumor location.

Adenocarcinoma↗

PubMed1999

Clinicopathologic prognostic features in patients with gastric cancer associated with esophageal or duodenal invasion.

BACKGROUND: We evaluated the influence of several clinicopathologic variables on 5-year survival of patients with gastric cancer associated with esophageal or duodenal invasion, and determined the significance of resection line involvement. PATIENTS AND METHODS: A review of the database for gastric adenocarcinoma at Sendai National Hospital between January 1985 and December 1995 identified 923 patients who underwent gastric cancer resection. Of these patients, 37 were reported to have tumour infiltration of the esophagus or duodenum on histological examination of the resected specimens. Univariate and multivariate analyses of patients with esophageal or duodenal invasion were performed to evaluate the prognostic significance of clinicopathologic features. Then the patients were divided into two groups based on the results of microscopic examination: a tumour wedge-positive group for resection margins of less than 5 mm in width and a tumour wedge-negative group for resection margins of more than 5 mm in width. There were 8 patients in the narrow (margin-positive) group and 29 patients in the wide margin (margin-negative) group, respectively. RESULTS: Univariate analysis revealed that the significant prognostic factors were nodal involvement (p=0.0004) and gross type (p=0.0031). Multivariate analysis of the esophagus or duodenum-invaded cancer cases, however, revealed that only nodal involvement was a significant prognostic factor. There were statistical correlations between these groups (margin-positive and margin-negative groups) and the Borrmann type of tumour and tumour size. The survival rate was worse in patients with tumour line involvement. CONCLUSIONS: Multivariate analysis revealed that the prognosis of patients with esophageal or duodenal invasion was affected only by nodal involvement independently. The risk of surgical margin involvement was high in cases of a large Borrmann type-4 tumour and infiltrative carcinoma.

Adult↗

PubMed1999

Malignant fibrous histiocytoma: a method to control intraoperative hemorrhage by clamping the feeding arteries.

Malignant fibrous histiocytoma (MFH), also referred to in the past as malignant fibrous xanthoma and fibroxanthosarcoma, is a tumor of mesenchymal tissue origin. A case of retroperitoneal MFH was reported. In this paper, we describe a method of hemostasis and intraoperative control of hemorrhage during resection of retroperitoneal MFH by snaring the feeding arteries. The patient was successfully operated on using this technique.

Arteries↗

PubMed1999

[Methicillin-resistant Staphylococcus aureus (MRSA) mediastinitis after cardiovascular operations].

We described three cases of poststernotomy mediastinitis caused by MRSA. The first case 74-year-old woman who had undergone emergent CABG was treated by continuous closed irrigation and consecutive omental transfer. She was suffered from multiple organ failure and died. The other two cases 50-year-old woman and 66-year-old man after double valves replacement and total aortic arch replacement were managed successfully with simultaneous combination of surgical debridement and placement of omental flap. It was seemed that early aggressive surgical procedures before deterioration of general conditions associated with improvement of mortality. Additionally, it was considered that to avoid residual dead space in presternum as well as in mediastinum was essential to decrease the morbidity and hospital stay, especially in case of MRSA infection.

Aged↗

PubMed1999

[A case of mitral valve replacement and left atrial plication for infantile Marfan syndrome with giant left atrium due to mitral valve regurgitation].

In Marfan syndrome, there is a subset, called infantile Marfan syndrome, in which the disease is diagnosed during infancy and cardiac lesions including mitral regurgitation and aortic root dilatation tend to be deteriorated rapidly. In infantile Marfan syndrome, respiratory function is sometimes impaired when skeletal abnormalities such as scoliosis and pectus excavatum are severe. In this report, we describe a 2-year and 4-months old boy with infantile Marfan syndrome who presented with severe mitral regurgitation and the collapsed left lung. In addition to the impairment of respiratory function due to severe scoliosis, the left lung was collapsed because of the compression of the left bronchus by the enlarged left atrium. The patient required mitral valve replacement concomitantly with left atrial plication, resulting in the decompression of the left bronchus and the re-expansion of the left lung. Characteristics and surgical management of infantile Marfan syndrome are discussed in this report.

Child, Preschool↗

PubMed1999

[Cerebral hemodynamics and risk for recurrent stroke in symptomatic internal carotid artery occlusion].

PURPOSE: In internal carotid artery occlusion, patients with inadequate blood supply relative to metabolic demand (misery perfusion) may be at increased risk for cerebral ischemia. This study investigated whether patients demonstrating misery perfusion on positron emission tomography (PET) have a high risk of subsequent stroke in symptomatic internal carotid artery occlusion. METHODS: We prospectively evaluated the relationship between the regional hemodynamic status of cerebral circulation and the subsequent risk of stroke in 40 patients with symptomatic internal carotid artery occlusion who underwent PET. Patients were divided into two hemodynamic categories according to the mean hemispheric value of oxygen extraction fraction (OEF) in the hemisphere supplied by the artery with symptomatic disease: patients with increased OEF and those with normal OEF. All patients were followed with medical treatment until the recurrence of stroke or death for 3 years. RESULTS: The three-year incidence of ipsilateral ischemic strokes for patients with normal OEF and those with increased OEF were 1 of 34 and 3 of 6 patients, respectively. A significantly higher incidence of ipsilateral strokes was found in patients with increased OEF (Kaplan-Meier analysis and log-rank test; p < 0.001). Multivariate analysis with the Cox proportional hazards model demonstrated that increased OEF significantly increased stroke recurrence: the relative risk was 19.5 (95% CI, 2.0-188.6) for ipsilateral stroke. An increase in the absolute OEF value was a better predictor of recurrent ischemic stroke than an OEF asymmetry. CONCLUSION: These findings suggest that patients with symptomatic internal carotid artery occlusion and misery perfusion have a high risk for subsequent stroke. Thus, identification and optimal treatment of patients with misery perfusion may be essential in preventing stroke.

Aged↗

PubMed1999

Exacerbation of acute pancreatitis in the presence of chronic liver injury in rats, with special reference to therapeutic efficacy of prostaglandin E1.

The pathophysiology of acute pancreatitis accompanied by chronic liver injury, and the therapeutic efficacy of prostaglandin (PG)E1 were studied experimentally in rats. Chronic liver injury was produced by subcutaneous administration of CCl4. Acute pancreatitis was induced by the closed duodenal loop (CDL) method, immediately after which PGE1 (60 ng/kg/min) was infused intravenously via the jugular vein. Serum levels of amylase, alpha2-macroglobulin-trypsin complex (alpha2M-TRY), C-reactive protein (CRP), and tumor necrosis factor-alpha (TNF-alpha) were determined before and at 3 and 6 h after the onset of acute pancreatitis. Rats without administration of CCl4 served as controls. Serum amylase levels were lower in the liver injury (LI) group than in the normal liver (NL) group at 3 and 6 h. PGE1 had no effect on amylase levels in either group. Serum alpha2M-TRY levels were similar in the two groups at 3 h, but significantly higher in LI than in NL at 6 h. PGE1 tended to decrease alpha2M-TRY levels only in LI. Serum CRP levels were significantly more elevated in LI than in NL at 0, 3, and 6 h. PGE1 decreased CRP levels only in LI. Serum TNF-alpha concentrations were higher in LI, especially at 6 h. PGE1 reduced TNF-alpha levels in LI. Pancreatitis severity scores were significantly higher in LI. PGE1 significantly decreased the severity scores only in LI. Fat necrosis scores were significantly lower in LI. Histologically, interstitial edema was much more prominent in NL than in LI, whereas interstitial hemorrhage was more severe in LI at 3 and 6 h. PGE1 lessened the hemorrhage in LI. The extent of both vacuolization and necrosis of acinar cells was similar for both groups and tended to be improved by PGE1. It is concluded that acute pancreatitis becomes much more serious in the presence of chronic liver injury, and that PGE1 can ameliorate the exacerbated lesions, probably by improvements in blood flow through the pancreatic tissue.

Acute Disease↗

PubMed1999

[A case of spontaneous hemopneumothorax associated with uncontrolled massive bleeding after inserting thorathic drain].

A 31-year-old man admitted to our hospital complaining of right chest pain. Chest X-ray on admission revealed a collapsed lung and an air fluid line in the right thorax. A chest tube drainage was carried out, but hemorrhagic pleural fluid was drainaged. Forty minutes later, an anemia developed and chest X-ray showed increased massive right pleural collection. Therefore, emergent surgery was performed. An operation under thoracoscopic guidance was converted into thoracotomy because of massive blood clots and fresh bleeding. A bleeding originating from the branch of 1st intercostal artery and a bulla on upper lobes were noted. The artery was coagulated with electrocoutary and ligated using Endo-loop. This artery is not congenital abnormal one but collateral expanded one of which the elastic lamina is thickened. Spontaneous hemopneumothorax is life-threatening, emergent operation should be undergone.

Adult↗

PubMed1999

Borrmann's type IV gastric cancer: clinicopathologic analysis.

OBJECTIVE: To determine whether there is a specific pattern of clinicopathological features that could distinguish Borrmann's type IV gastric cancer from other types of gastric cancer. DESIGN: A retrospective study of patients with advanced gastric cancer treated between 1985 and 1995. SETTING: The Department of Surgery, Sendai National Hospital, a 716-bed teaching hospital. PATIENTS: The clinicopathologic features of 88 patients with Borrmann's type IV carcinoma of the stomach were reviewed from the database of gastric cancer. The results were compared with those of 309 patients with other types of gastric carcinoma. MAIN OUTCOME MEASURES: Gender, age, tumour size, depth of invasion, histologic type, cancer-stromal relationship, histologic growth pattern, nodal involvement, lymphatic and vascular invasion, type of operation, cause of death and 5-year survival. RESULTS: Women were afflicted as commonly as men in the Borrmann's type IV group. These patients tended to be younger and to have larger tumours involving the entire stomach than patients with other types of cancer. Histologic type was commonly diffuse and scirrhous, and serosal invasion was prominent with infiltrative growth. Nodal involvement and lymphatic invasion were more common in patients with Borrmann's type IV than in those with other types of gastric cancer. The disease was advanced in most instances and a total gastrectomy was performed in 55% of the patients. The survival rate of patients with Borrmann's type IV tumour was lower than for patients with other types of gastric cancer (p < 0.005, log-rank test). CONCLUSIONS: In Borrmann's type IV gastric cancer, early detection and curative resection are crucial to extend the patient's survival. Aggressive postoperative chemotherapy is recommended when a noncurative resection is performed.

Adenocarcinoma↗