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T Hirai

Publications and source records attributed to T Hirai.

At least 91 records · Page 5Linked to original sources
PubMed2000

Evaluation of syringomyelia with three-dimensional constructive interference in a steady state (CISS) sequence.

The purpose of this study was to evaluate a three-dimensional (3D) constructive interference in steady state (CISS) sequence in the assessment of syringomyelia. Eleven patients with syringomyelia were prospectively studied with magnetic resonance imaging. All patients underwent sagittal imaging with T1- and T2-weighted spin-echo (SE), and 3D-CISS sequences. The SE and 3D-CISS images, as well as multiplanar reconstruction (MPR) images of the 3D-CISS sequence, were analyzed with regard to image quality, degree of artifacts, visualization of the extent and internal structure of the syringomyelia, and contrast-to-noise ratio (CNR) of the fluid within the syringomyelia. Contrast between the spinal cord and cerebrospinal fluid (CSF), as well as delineation was significantly poorer for the T1-weighted SE sequence than for the 3D-CISS sequence (P < 0.01), while there was no significant difference between the T2-weighted SE sequence and the 3D-CISS sequence. Artifacts induced by CSF flow were significantly more for the T2-weighted SE sequence than for the 3D-CISS sequence (P < 0.01). Although the extent of syringomyelia was delineated equally among the three sequences in 9 of 11 patients, it was better for the 3D-CISS sequence than for the SE sequences in the remaining two. Septation and communication between the cavities were best detected by the 3D-CISS MPR images. The CNR of the 3D-CISS sequence was significantly higher than that of the SE sequence (P < 0.01). The 3D-CISS sequence demonstrates the extent and internal structures of syringomyelia better than conventional SE sequences and should be added to SE sequences in the evaluation of syringomyelia.

Adult↗
PubMed2000

Relation of transesophageal echocardiographic findings to subtypes of cerebral infarction in patients with atrial fibrillation.

BACKGROUND: Transesophageal echocardiography (TEE) has been used to identify the potential risk for cardiogenic embolism in patients with atrial fibrillation (AF). However, ischemic stroke in patients with AF is not always attributable to embolism. Identification of the risk of embolic versus atherothrombotic stroke should lead to the optimal individualized management of patients with AF. HYPOTHESIS: The goal of the study was to determine the relation between cortical infarction and perforating infarction and TEE findings in patients with AF. METHODS: We investigated the clinical usefulness of TEE in the risk stratification of clinical subtyping of the cerebral infarctions which were divided into two territories of the cortical branch (cortical infarction due to embolism) and deep perforators (perforating infarction due to atherothrombosis). Left atrial spontaneous echo contrast, peak flow velocity in the left atrial appendage, and generalized atherosclerosis as estimated by the intima-media wall thickness of the thoracic aorta were assessed by TEE in 118 consecutive patients with either paroxysmal (n = 44) or chronic (n = 74) AF. All patients underwent either brain computed tomography or magnetic resonance imaging. RESULTS: Cortical and perforating infarction was found in 39 and 18% of patients, respectively. The grade of spontaneous echo contrast was higher in patients with than in those without cortical infarction (p < 0.05). In contrast, patients with perforating infarction showed significant increase in the aortic wall thickness when compared with patients without perforating infarction (p < 0.05). In addition, multivariate logistic analysis revealed that spontaneous echo contrast was an independent predictor of cortical infarction, while intima-media wall thickness of the aorta, hypertension, and age were useful in predicting the risk of perforating infarction. CONCLUSIONS: Transesophageal echocardiography has a potential role in the risk stratification for cortical and perforating infarction in patients with AF.

Aged↗
PubMed2000

Primary gastric B cell lymphoma: audit of 82 cases treated with surgery and classified according to the concept of mucosa-associated lymphoid tissue lymphoma.

There has been a trend toward stomach conservation during treatment for primary gastric lymphoma, but surgery ensures accurate pathologic diagnosis through the examination of resected specimens. A histopathologic classification for primary gastric lymphoma had been established with the knowledge that the low grade and high grade components occasionally coexist in a single lesion. Efficacy of this classification as an indicator of biologic behavior and prognosis was evaluated. The classification was performed by reexamining surgically resected specimens from 82 patients with stage IE and IIE gastric lymphoma. Clinical characteristics of the low grade and high grade lymphomas were then evaluated and the survival data analyzed. Despite the larger tumor diameter, the depth of invasion for the low grade type was mostly submucosal, and none had serosal invasion. In contrast, 50% of the high grade type had serosal involvement and were also found to have a higher incidence of node metastasis. Prognosis of the low grade type, a 10-year survival rate exceeding 90%, was significantly better than that of the high grade type. Multivariate analysis revealed that curability of the operation followed by the histopathologic grade were significant independent prognostic factors. Some characteristics of the low grade lymphoma were not consistent with what has been reported in the studies involving stomach-conserving strategies. Investigators are advised to note that the histopathologic grade determined with biopsy specimens alone could be misleading.

Adult↗
PubMed2000

Multifocal micronodular pneumocyte hyperplasia in a postmenopausal woman with tuberous sclerosis.

We report a peculiar case of multifocal micronodular pneumocyte hyperplasia (MMPH) without association of pulmonary lymphangioleiomyomatosis (LAM) in a 56-year-old postmenopausal woman with tuberous sclerosis. This case is surmised to be a forme fruste of tuberous sclerosis. Computed tomography demonstrated multiple micronodules, measuring up to 5 mm in size, present in the bilateral lung fields, but no cystic changes. A proliferation of pleomorphic type-II pneumocytes lining the thickened alveolar septa in an adenomatoid pattern, with an associated increase in alveolar macrophages, was observed without typical nuclear atypia. In fully developed lesions, the ingrowth of more proliferating type-II pneumocytes into the thickened alveolar septa and macrophages filling the alveolar lumens were characteristic findings. Proliferation of immature smooth muscle cells suggesting LAM was not observed. Positive immunohistochemical stains for cytokeratin, epithelial membrane antigen, and surfactant apoproteins A and B, and negative staining for HMB45, alpha-1 smooth muscle actin, desmin, and carcinoembryonic antigen confirmed the characteristics of alveolar lining cells in each MMPH lesion. MMPH associated with tuberous sclerosis in the postmenopausal woman appears to be similar to that described in premenopausal women. The present case is familial rather than sporadic and suggests no relationship between the development of MMPH and the underlying hormonal state.

Female↗
PubMed2000

Analyses of segmental lymph node metastases and intrapulmonary metastases of small lung cancer.

BACKGROUND: Curativity and indications for limited resection of small peripheral lung cancer remain controversial. METHODS: Pathologic investigations of segmental lymph node metastases and intrapulmonary metastases in the resected lobe were performed for 94 small peripheral lung cancers (3.0 cm or less in diameter). RESULTS: Nine patients had segmental lymph node metastases, 1 had intrapulmonary metastases, and 1 had both. Of these 11 patients, 5 had metastases limited to the primary tumor-bearing segments, 2 had metastases in nonprimary tumor-bearing segments, and 4 had metastases in both. Of the 10 patients with segmental lymph node metastases, 7 had metastases in both lobar-hilar and mediastinal lymph nodes, and 3 of 8 with adenocarcinoma had a tumor 2.0 cm or less. CONCLUSIONS: Segmentectomy seems more favorable than wedge resection, but the risk of remnant tumor remains as compared with lobectomy. Evaluation of lobar-hilar or mediastinal lymph nodes is helpful to determine the presence or absence of segmental lymph node metastases. Limited resection can be undertaken with smaller tumors to allow preservation of more lung function while accepting a somewhat enhanced risk of recurrence.

Adenocarcinoma↗
PubMed2000

Manometric and hormonal changes after distal partial gastrectomy.

BACKGROUND: Alkaline oesophagitis attributable to duodenal mechanisms may induce oesophageal carcinogenesis in a rat reflux model. AIM: To investigate the mechanism of the regurgitation after distal partial gastrectomy. METHODS: Oesophageal manometry was used in 16 patients before and after distal partial gastrectomy with reconstruction by Bilroth methods. Serum concentrations of four gastrointestinal hormones were measured by radioimmunoassay in 10 gastrectomy patients and nine healthy volunteers before and after a standardized meal. RESULTS: The lower oesophageal sphincter pressure was reduced to 83% after surgery. The amplitude and duration of the peristaltic waves tended to be increased, and the velocity tended to be less after surgery (amplitude 120%, duration 114%, velocity 88%). Interrupted waves appeared more frequently after surgery. The manometric changes in gastrectomized patients are considered to be disadvantageous relative to regurgitation. After surgery, gastrin and pancreatic polypeptide were completely abolished postprandially, whereas cholecystokinin and neurotensin were significantly increased. CONCLUSION: The hormonal changes should have a suppressive effect on the lower oesophageal sphincter. Both the manometric and the hormonal changes may exacerbate reflux oesophagitis after distal partial gastrectomy.

Aged↗
PubMed2000

Alpha-fetoprotein producing uterine corpus carcinoma: A hepatoid adenocarcinoma of the endometrium.

A case of alpha-fetoprotein (AFP) producing endometrial carcinoma in a 60-year-old Japanese woman is presented. The patient complained of abnormal vaginal bleeding of 10 days' duration. On admission a uterine corpus mass and high serum AFP concentration (31950 ng/mL) was noted. There was no tumorous lesion in any other organ radiographically and endoscopically. Histologically, the biopsy specimen taken from the uterine mass showed a poorly differentiated endometrial carcinoma and a radical hysterectomy was subsequently performed. The postoperative serum AFP value transiently decreased with chemotherapy, however, lung metastases were found and the patient died 12 months following surgery. The resected uterus had a necrotic tumor, 6 x 5 x 4 cm in size, filling the endometrial cavity, characterized by exophytic growth with infiltration in the myometrium. Histologically, the tumor was composed of the main medullary carcinoma area with microcysts and admixed small areas of well-differentiated endometrioid adenocarcinoma, accompanied by a smooth transition with one another. In both the areas, the tumor cells had immunoreactive AFP, alpha-1-antitripsin, albumin, transferrin, carcinoembryonic antigen, CA19-9, and epithelial membrane antigen. There was no histologic evidence for a germ cell tumor. Based on these findings, this uterine corpus tumor was regarded as hepatoid variant of endometrial carcinoma. Although the histogenesis remains controversial, we assume the hypothesis that the tumor may arise in the endometrium per se in association with abnormal differentiation of muellerian duct elements.

Adenocarcinoma↗
PubMed2000

Significance of the expression of p27Kip1 in esophageal squamous cell carcinomas.

Recent observations have demonstrated that the reduced expression of p27Kip1 (p27) is correlated with progression and poor prognosis of breast, colon, and gastric carcinomas. These observations led us to examine the expression of p27 and cyclin D1 and E protein in six esophageal carcinoma cell lines and 81 esophageal carcinoma tissues by Western blot analysis and immunohistochemistry. The expression levels of cyclin D1 and p27 were correlated clearly in esophageal carcinoma cell lines by Western blot analysis. Immunohistochemical analysis revealed that the high-grade expression of p27 protein was detected in 61% of esophageal carcinomas, and it was correlated with tumor invasion, lymph node metastasis, and poor patient prognosis. This observation was different from the results reported in other organs. Cell cycle regulation is a very complicated process. Homeostatic feedback mechanisms against the overexpression of cyclin D1 may exist in esophageal carcinomas, and there can be organ-specific regulations in the progression of carcinomas.

Adult↗
PubMed2000

Significance of lymph node dissection of the superior mediastinal region in esophageal cancer patients.

The effect of the superior mediastinal lymph node dissection was compared retrospectively with that of standard dissection in 108 esophageal cancer patients. Five-year survival rates were 46.3% in patients who underwent standard surgery (group A) and 39.3% in patients who underwent superior mediastinal lymph node dissection (group B). The survival curves were basically the same. Nineteen out of 42 (45.2%) tumors in group A and 24 out of 66 (36.4%) tumors in group B recurred. The distribution of the first sites of recurrence did not differ significantly between groups. However, 14 tumors (67%) in group A recurred in the lymph nodes, but only seven tumors recurred (28%) in the lymph nodes in group B. Eleven tumors (52%) in group A recurred to superior mediastinal nodes, but only one tumor (4%) recurred to a superior mediastinal node in group B. Fourteen of the group B patients showed metastasis to superior mediastinal lymph nodes and none of these patients survived for more than 5 years. Eleven of these 14 patients showed metastasis to only one or two nodes. Based on our data and other reported findings, we conclude that extended lymphadenectomy of the superior mediastinal region alone does not contribute to improved survival of esophageal cancer patients, but it does contribute to the prevention of lymph node recurrence in this region.

Carcinoma, Squamous Cell↗
PubMed2000

The 11 A resolution projection map of Na+/K+-ATPase calculated by application of single particle analysis to two-dimensional crystal images.

Two-dimensional (2D) crystals of Na+/K+-ATPase were vitrified and observed with an electron cryo-microscope that allowed specimen observation at liquid helium temperature. Images showing 19 A spots on the optical diffraction patterns were digitized and processed by a crystallographic method. After optimization of parameters for the image processing, the locally averaged images revealed that each 2D crystal contained heterogeneous molecules. Single particle analysis was therefore applied to the 2D crystal images to select homogeneous molecule images, and averaging the selected images significantly improved map quality. Five major peak densities were clearly resolved in the new projection map, while two were found previously.

Animals↗
PubMed2000

Intranasal sensitization of Japanese cedar pollen by the co-administration of low doses of cholera toxin but not its recombinant B subunit to mice.

We evaluated the effects of cholera toxin (CT) and the B subunit of cholera toxin (CTB) on the intranasal sensitization of Japanese cedar pollen (JCP) in mice. JCP suspended in phosphate-buffered saline was administered into the nostrils of mice in combination with varying doses of CT or recombinant CTB(r-CTB) once a week for 5 weeks. Antibody responses specific to sugi basic protein (SBP) were monitored by ELISA for seven weeks. The sensitization of JCP alone did not induce IgG1, IgG2b, IgG2a, IgE or IgA. In contrast, sensitization of JCP in combination with CT (JCP/CT) elicited the prominent production of SBP-specific IgG1 and low levels of IgG2b and IgG2a on Day 49. IgE production was detected only in the serum of mice which were treated with JCP/CT, and not under any other protocol. Using spleen cells from these mice, cytokine production was examined by ELISA in culture supernatants after they had been stimulated in vitro with major cedar pollen allergens, Cry j 1, Cry j 2 or SBP. Notable responses were an increase of IFN-gamma as well as IL-4 in JCP/CT-sensitized cells stimulated with Cry j 2, but not in those stimulated with Cry j 1. No significant differences were detected in IL-5 production among the experimental groups. Histopathological examination, however, showed that eosinophil infiltration was evident in the nasal mucosa of the JCP/CT-sensitized mice following challenge with JCP/CT, but weak with BSA/CT or CT alone. Thus, the immunological and histological analyses indicated that the co-administration of a low dose of CT in combination with JCP allows the induction of pollen-allergic states in mice.

Adjuvants, Immunologic↗
PubMed2000

A case of cancerous familial adenomatous polyposis in urinary bladder due to migration of colonic mucosa through rectovesical fistula.

The patient was a 50-yr-old man who had undergone low anterior resection for rectal cancer at the age of 24 yr in 1966. At that time, gastric and colonic polyposis were indicated. Postoperative anastomotic dehiscence occurred and, by 1985, a rectovesical fistula had formed. In 1986, when the patient was 44 yr old, he was examined at our hospital for constriction of the rectum due to the rectovesical fistula. Abdominoperineal excision of rectum and surgical closure of the fistula were performed, and the patient was kept under observation because of a diagnosis of familial adenomatous polyposis. In 1988, when the patient was 46 yr old, early ascending colon cancer was discovered and total colectomy was performed. Then, in December, 1991, gross hematuria was found. Further examination revealed a tumor on the posterior wall of the urinary bladder lumen, and biopsy showed adenocarcinoma. Pelvic recurrence of the rectal cancer was diagnosed, and total pelvic exenteration was performed. There were no distant metastases; histologically, the tumor of the bladder was thought to be due to colonic mucosa of familial adenomatous polyposis that had migrated to the bladder lumen via the rectovesical fistula and had become cancerous.

Adenomatous Polyposis Coli↗
PubMed2000

Limbic lobe of the human brain: evaluation with turbo fluid-attenuated inversion-recovery MR imaging.

PURPOSE: To determine whether brain cortices have different signal intensities on turbo fluid-attenuated inversion-recovery (FLAIR) magnetic resonance (MR) images. MATERIALS AND METHODS: Coronal 5-mm-thick turbo FLAIR MR images in 56 neurologically normal patients (27 male and 29 female patients; age range, 12-73 years; mean age, 47 years) were evaluated retrospectively. Cortical signal intensities in the amygdala, hippocampus, cingulate gyrus, subcallosal area, insula, temporal lobe, parietal lobe, and occipital lobe were graded relative to cortical signal intensity in the frontal lobe. Contrast-to-noise ratios were compared for each cortical area. RESULTS: Increased signal intensity was frequently seen in the amygdala, hippocampus, cingulate gyrus, and subcallosal area, regardless of patient age. Signal intensities of temporal, parietal, and occipital cortices were similar to that of frontal cortex, and signal intensity of the insula was slightly higher than that of frontal cortex. There were no significant differences with respect to sex and laterality, whereas significant differences were found among cortical regions (P <.01). The contrast-to-noise ratios of the amygdala, hippocampus, cingulate gyrus, and subcallosal area were significantly greater than those of all other gray matter structures (P <.05). CONCLUSION: On turbo FLAIR images, high signal intensities of cortices of the limbic lobe are frequently seen in neurologically normal brain. These findings should not be considered abnormal.

Adolescent↗
PubMed2000

Distorted trachea in patients with chronic obstructive pulmonary disease.

BACKGROUND AND OBJECTIVES: We evaluated the size and configuration of the trachea in patients with chronic obstructive pulmonary disease (COPD; n = 35) on high-resolution computed tomography (HRCT) images and compared them with those of healthy volunteers (n = 24). METHODS: Using a newly developed computed method for analyzing the digital data of HRCT, the size and configuration of the trachea were automatically evaluated. RESULTS: The size of the trachea of the COPD subjects was the same as that of the control subjects; however, the configuration was more distorted in the COPD patients. There was no difference in the tracheal index (TI), which is the ratio of the coronal to the sagittal length, between these two groups; however, the ratio of the short to the long radius (SR/LR) was significantly smaller in the COPD group than in the control group. There was a significant correlation between SR/LR and airflow limitation as assessed by pulmonary function tests in the COPD group. CONCLUSIONS: The SR/LR is a better index of tracheal deformity than the classical TI. This deformity is not a consequence secondary to hyperinflation or emphysematous change of the lung, because the low attenuation area of the lung was not correlated with SR/LR.

Aged↗
PubMed2000

Computed tomographic measurements of airway dimensions and emphysema in smokers. Correlation with lung function.

Chronic obstructive pulmonary disease (COPD) is characterized by the presence of airflow obstruction caused by emphysema or airway narrowing, or both. Low attenuation areas (LAA) on computed tomography (CT) have been shown to represent macroscopic or microscopic emphysema, or both. However CT has not been used to quantify the airway abnormalities in smokers with or without airflow obstruction. In this study, we used CT to evaluate both emphysema and airway wall thickening in 114 smokers. The CT measurements revealed that a decreased FEV(1) (%predicted) is associated with an increase of airway wall area and an increase of emphysema. Although both airway wall thickening and emphysema (LAA) correlated with measurements of lung function, stepwise multiple regression analysis showed that the combination of airway and emphysema measurements improved the estimate of pulmonary function test abnormalities. We conclude that both CT measurements of airway dimensions and emphysema are useful and complementary in the evaluation of the lung of smokers.

Adult↗
PubMed2000

Effect of hydrogen peroxide on guinea pig nasal mucosa vasculature.

The effect of hydrogen peroxide (H2O2) on guinea pig nasal mucosa vasculature was studied by in vitro assay. H2O2 elicited relaxation of guinea pig nasal mucosa strips precontracted with phenylephrine in a concentration-dependent manner. The relaxant response to H2O2 was abolished in the presence of catalase. Preincubation of the strips with N(G)-nitro-L-arginine methyl ester or methylene blue significantly attenuated the relaxant responses elicited by H2O2. Fluorescence caused by DAF-2 DA, a fluorescence indicator for nitric oxide, was observed along the nasal mucosa vasculature in response to H2O2. These results suggest that H2O2 induced relaxation of the guinea pig nasal mucosa vasculature and that this relaxation is mediated by the NO/cGMP pathway.

Animals↗
PubMed2000

Exercise capacity of thoracotomy patients in the early postoperative period.

OBJECTIVE: We investigated the mechanism involved with the initial drop and subsequent recovery of exercise capacity in the early postoperative period of thoracotomy patients. METHODS: Sixteen patients (13 who had undergone lobectomy, 3 who had undergone pneumonectomy) underwent a routine pulmonary function test (PFT) and a cardiopulmonary exercise test preoperatively, within 14 postoperative days (POD; post-1; mean +/- SD, 9 +/- 2 POD), and after 14 POD (post-2; mean, 26 +/- 12 POD). RESULTS: After surgery on post-1, PFT results of FVC, FEV(1), and maximum ventilatory volume (MVV) significantly decreased. Oxygen uptake (VO(2)) at a venous blood lactate level of 2.2 mmol/L (La-2. 2), which was adopted as the empirical anaerobic threshold, and maximum V O(2) (VO(2)max) decreased significantly to 88.2 +/- 7.9% and 73.1 +/- 15.4% of the preoperative values, respectively. La-2.2 min ventilation (VE)/ MVV and maximum VEmax)/MVV increased significantly from 0.36 +/- 0.08 to 0. 66 +/- 0.20 and from 0.58 +/- 0.14 to 0.80 +/- 0.09, respectively. On post-2, though La-2.2 VO(2) did not change, VO(2)max improved significantly to 81.5 +/- 19.7% of the preoperative values, in association with significant increases in maximal tidal volume and VEmax, which were produced by significant increases in the PFT results. La-2.2 VE/MVV also decreased significantly to 0.49 +/- 0.13, which indicated a sufficient recovery of respiratory reserve at submaximal exercise. CONCLUSIONS: The initial drop of exercise capacity after lung resection seems to be derived from both circulatory and ventilatory limitations. Further, the subsequent recovery within 1 month seems to be produced by an improvement in ventilatory limitation, which was caused by the surgical injury to the chest wall.

Adaptation, Physiological↗