Biomedical subjects

H Yano

Publications and source records attributed to H Yano.

547 records · Page 31Linked to original sources

PubMedDate not supplied

Functional imaging of the human olfactory cortex by magnetic resonance imaging.

Our understanding of the neural mechanism of human olfaction is still equivocal. Several recent reports document that functional magnetic resonance imaging (MRI) has a potential to visualize dynamic brain function in humans without invasion. In the present study, we applied functional MRI with odor stimulation for the purpose of clarifying the localization of olfactory cortices in the human. We obtained a significant increase in cerebral blood flow in the piriform cortex, orbitofrontal cortex, and inferior medial frontal lobe, corresponding to olfactory cortices. These results suggest that, in the near future, precise diagnosis of the patients with olfactory disorders will be possible using functional MRI with odor stimulation.

Adult↗

PubMedDate not supplied

Expression and localization of vascular endothelial growth factor receptors in human hepatocellular carcinoma and non-HCC tissues.

Flt-1 (VEGF receptor-1) and KDR/Flk-1 (VEGF receptor-2) are the high-affinity receptors for the angiogenesis factor, vascular endothelial growth factor (VEGF). VEGF expression has been confirmed in human hepatocellular carcinoma (HCC), and VEGF is thought to be involved in the angiogenesis within HCC tissues. However, expressions of VEGF receptors in HCC have not been reported. We immunohistochemically examined expressions and localizations of Flt-1 and KDR in 28 surgically resected HCC tissues. In non-cancerous area, Flt-1 and KDR were mainly found in macrophages including Kupffer cells; both receptors were found in vascular endothelial cells in the portal veins and arteries within portal tracts; and KDR was also found in some sinusoidal endothelial cells. In cancerous area, Flt-1 and KDR were found in some macrophages, and also in the endothelial cells of intratumoral blood vessels. In 25 moderately and/or poorly differentiated HCCs, KDR expression in the blood space endothelial cells was clear and continuous in 20 cases, and focal in 5 cases. These results suggest that there would be an angiogenesis mechanism via VEGF/Flt-1 or VEGF/KDR in HCC, and the VEGF/KDR system would take a more important role.

Carcinoma, Hepatocellular↗

PubMedDate not supplied

Diagnosis of pancreatic cancer by cytology and measurement of oncogene and tumor markers in pure pancreatic juice aspirated by endoscopy.

BACKGROUND/AIMS: Cytological examination of pancreatic juice is useful in the diagnosis of an occult cancer of the pancreas. The early diagnosis of pancreatic carcinoma using traditional radiographic or ultrasonographic methods is extremely difficult. METHODOLOGY: In order to detect an early pancreatic cancer, cytological examination, measurement of tumor marker, and detection of K-ras point mutation were performed using the samples of pure pancreatic juice aspirated endoscopically in patients who had symptoms or findings that suggested pancreatic disease. RESULTS: By routine ERP-cytology, positive cytologic results were obtained in 15 (4%) out of 359 patients without a mass. With the aid of intra-operative cytodiagnosis, all 15 occult neoplasms of the pancreas were successfully resected. One patient died from another disease without evidence of recurrence. However, the other patients were alive with no evidence of recurrence for an average of 5.5 years following surgery. The patients who had negative ERP-cytology results were observed, but no further cases of pancreatic cancer were found. The CEA levels in the pure pancreatic juice were significantly higher in patients with pancreatic cancer than in those with pancreatitis. K-ras point mutation at codon 12 was detected not only in cases of pancreatic cancer, but also in cases of chronic pancreatitis as well as control subjects. CONCLUSIONS: Cytological examination of pancreatic juice is useful in the diagnosis of an early and potentially curable in situ cancer of the pancreas. The CEA levels in the pure pancreatic juice provided useful information for differentiating the pancreatic cancer from chronic pancreatitis. K-ras point mutation at codon 12 in pancreatic juice was considered to be useful in identifying patients at high risk for the development of pancreatic cancer.

Aged↗

PubMedDate not supplied

Endoscopic resection with a two-channel videoendoscope for gastric carcinoid tumors.

BACKGROUND/AIMS: Endoscopic resection has been used to treat hypergastrinemia-associated early carcinoid tumors of the stomach. However, indications for endoscopic treatment of these tumors have not been established. Moreover, endoscopic resection of these tumors is often difficult with conventional polypectomy, because these tumors are often located in the submucosal layer. To completely remove these tumors, we used a two-channel videoendoscope with which both grasping forceps and a polypectomy snare could be used simultaneously. METHODOLOGY: At Osaka Medical Center for Cancer and Cardiovascular Diseases, eight carcinoid tumors in six patients were removed with a two-channel videoendoscope. Reports of early carcinoid tumor in Japanese literature were reviewed to analyze the relationship between lymph node metastasis and the size and depth of involvement of these tumors. RESULTS: Six carcinoid tumors were completely removed "en bloc", but two tumors were incompletely removed. In these two patients, submucosal tumor invasion was observed on the excision line. To completely remove these tumors, the oral side, but not the top, of the tumor should be strongly grasped and pulled toward the center of the lumen as far as possible by the grasping forceps, which had been passed through the snare loop. Endoscopic follow-up studies showed no local recurrence in any patients with and without complete tumor resection during the average observation period of 30 months. A review of histological reports in Japanese literature showed that lymph node metastasis did not occur when the tumors were less than 10 mm in diameter, and could be completely removed by an endoscope. CONCLUSIONS: Endoscopic resection with a two-channel videoendoscope is a useful and safe method for resection of small carcinoid tumors of the stomach.

Aged↗

PubMedDate not supplied

Progressive bulbar dysfunction caused by a predominantly venous vascular malformation of the medulla oblongata.

We describe a 58-year-old patient with a rare predominantly venous vascular malformation of the medulla oblongata, which caused a progressive bulbar dysfunction consisting of hiccoughs, dysphagia, hoarseness, dysarthria, gait ataxia and dysuria over a period of 11 months. On autopsy, a large dilated vein with focal marked intimal fibroelastic thickening was present on the ventral surface of the medulla. Microscopically, moderate proliferation of capillaries and veins was observed which was confined primarily to the medulla. The veins displayed abnormal dilatation and tortuosity; prominent thickening of vessel walls was also present in the veins and capillaries. The venous abnormalities were prominent in the parenchyma of the medulla, but much less apparent in its subarachnoid space. Multifocal neuronal loss and gliosis were observed, most prominently in the inferior olives, hypoglossal, dorsal vagal and ambiguus nuclei. The histopathologic findings suggested that abnormal venous drainage within the parenchyma of the medulla was the most critical factor for the pathogenesis of this patient's neurologic symptomatology.

Autonomic Nervous System Diseases↗

PubMedDate not supplied

Six year experience with wrinkled ePTFE vascular prostheses for arteriosclerosis obliterans.

From November 1986 to January 1993, 97 wrinkled ePTFE prosthetic vascular grafts were implanted in 90 peripheral arterial reconstructions for 87 patients with arteriosclerosis obliterans (ASO) (79 men and 8 women). Grafts used in this series were 54 Vitagraft and 33 Technograft. Initial results for a period of as long as 6 years are summarized here. Forty-four (45.3%) grafts were implanted anatomically, and the remaining were extra-anatomically routed. The mean age of patients in the anatomic bypass group was 64.7 years, and that of patients in the other group was 71.4 years. Twenty-three (43.3%) grafts in the extra-anatomic group were anastomosed sequentially. Mean follow-up periods for each group were 32.4 months and 30.9 months, respectively. None of nine late deaths during the follow-up period was graft related. There was one primary obstruction in the anatomic group; in the extra-anatomic groups, primary graft occlusion occurred in four grafts. In addition, one perigraft seroma and one pseudoaneurysm requiring surgical repair were seen. Cumulative event free ratio for this group was 80.8% at 72 months. These results reveal that the wrinkled ePTFE graft is clinically applicable to arterial reconstruction for ASO with satisfactory long-term patency, even in extra anatomic sequential bypasses.

Aged↗

PubMedDate not supplied

Oxygen desaturation during sedation for colonoscopy in elderly patients.

BACKGROUND/AIMS: Conscious sedation increases the tolerance of patients to endoscopic examination, but arterial oxygen desaturation during endoscopy has often been reported. Elderly patients are considered to be at special risk. However, sedation-induced changes in cardiovascular function in the elderly have not been well investigated. Therefore, this study examined the effects of sedation on pulse rate, systolic blood pressure, and arterial oxygen saturation in elderly patients. METHODOLOGY: Twenty patients aged less than 60 years and 20 patients aged 60 years or more, scheduled to undergo colonoscopic removal of colorectal polyps, received 0.05 or 0.025 mg/kg body weight, respectively, of midazolam intravenously. Before, during, and after endoscopy, pulse rate, systolic blood pressure, and arterial oxygen saturation were recorded every 5 min with a pulse oximeter. RESULTS: Administration of midazolam had no significant effect on pulse and arterial systolic blood pressure in either group. In contrast, midazolam significantly reduced the levels of arterial oxygen saturation during and after endoscopy in both age groups. However, although patients aged 60 years or more received midazolam at half dosage, arterial oxygen saturation during endoscopy was significantly lower and the incidence of 5% or more oxygen desaturation was significantly higher than in the patients aged less than 60 years. CONCLUSIONS: Midazolam increases the tolerance of elderly patients to endoscopy, but it significantly lowers the level of arterial oxygen saturation and increases the incidence of desaturation. Continuous monitoring is especially valuable during endoscopy in the elderly.

Aged↗