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Biomedical subjects

M Shimada

Publications and source records attributed to M Shimada.

At least 1,009 records · Page 56Linked to original sources
PubMedDate not supplied

Hemispatial visual-searching impairment correlated with decreased contralateral parietal blood flow in Alzheimer disease.

BACKGROUND: Impairment of visuospatial attention in Alzheimer disease (AD) has not been fully investigated. Mendez et al reported that patients with AD showed hemispatial biases on visual search tasks. Parietal lobe involvement might be related to such impairment. The Picture Description Task is one of the most sensitive tests for detecting language disorders and might be also useful in assessing visual search. OBJECTIVE: The applicability of the Picture Description Task for evaluating hemispatial visual search impairment of AD was investigated, as well as whether the hemispheric difference in parietal blood flow is related to such impairment. METHODS: Thirty-four patients with AD and age-matched 16 normal subjects performed the Picture Description Task. The elements of the picture were divided into three portions: the right portions (five elements), the central portions (two elements), and the left portions (five elements), so as to assess the patients' hemispatial visual searching ability. Using single photon emission CT, the absolute regional cerebral blood flow (CBF) values at resting condition were calculated by the method of Kuhl et al. RESULTS: Fourteen patients with AD showed a decreased number of elements pointed out in the left portion of the picture, whereas 12 patients had decreased attention in the right portion. The remaining eight pointed only to the central portion. None of them showed hemispatial neglect on the figure copying tasks. The patients with decreased left spatial attention had lower CBF in the right parietal lobe, and vice versa. A significant negative (biologically meaningful) Spearman correlation was found between the right-left indices of the elements pointed out in the picture and the CBF values. CONCLUSIONS: The results suggest that the Picture Description Task is useful for assessing visual search, and impaired hemispatial visual search in AD is related to decreased contralateral parietal blood flow. The right-left asymmetry of the parietal CBF might be associated with hemispatial visual attention impairments in AD.

Aged↗
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Spontaneous regression of hepatocellular carcinoma--a case report.

We report a 72-year-old man with hepatocellular carcinoma, which showed spontaneous regression. He was diagnosed as having chronic hepatitis type C five years before admission. In January 1998, a liver mass was found by ultrasonography. In February, computed tomography showed a low-density mass, 3.5 cm in diameter in the S5 region. Although liver biopsy was not performed, findings obtained by computed tomography and ultrasonography indicated that the tumor was hepatocellular carcinoma. The levels of alpha-fetoprotein and PIVKA (protein induced by vitamin K antagonist)-II were increased to 1000 ng/mL and 2000 mAU/mL, respectively. The patient was admitted to our hospital in March 1998. At the time, the size of liver mass was reduced to 2.5 cm in diameter on computed tomography, and the tumor markers, alpha-fetoprotein and PIVKA-II, spontaneously decreased to the normal range. We considered that hepatocellular carcinoma of this patient regressed spontaneously. Because it was hard to exclude the possibility that the mass contained residual malignant cells, we resected the mass on April 28, 1998. Microscopically, the resected mass did not contain any malignant cells. The parenchyma surrounding tumor necrosis, which is reflected by severe inflammatory infiltration with lymphocytes, indicates spontaneous regression. Although the precise mechanism regarding spontaneous regression of hepatocellular carcinoma is not fully understood, either ischemia due to rapid growth of the tumor or some inflammatory mechanism may be involved in regression of hepatocellular carcinoma.

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Thrombectomy before hepatic resection for hepatocellular carcinoma with a tumor thrombus extending to the inferior vena cava.

Tumor thrombi of hepatocellular carcinoma occasionally invade into the inferior vena cava (IVC) through the hepatic vein. Once the tumor thrombus is dislodged, severe and lethal complications, such as pulmonary infarction, can develop. We successfully operated on a hepatocellular carcinoma (HCC) patient with a tumor thrombus extending to the IVC through the right hepatic vein. To avoid dislodging the thrombus during surgery, a thrombectomy using selective hepatic vascular exclusion was performed before a hepatic resection, which is the most dangerous procedure to dislodge the thrombus.

Carcinoma, Hepatocellular↗
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Beneficial effect of fluorocarbon reperfusion on postoperative cardiac dysfunction of transplanted heart.

Fluosol DA 20% (Fluosol) perfusion was used to protect ischemic donor hearts of mongrel dogs from reperfusion injury. Fifteen orthotopically transplanted hearts, eight in the control group and seven in the Fluosol group, were studied for 3 hours after weaning from cardiopulmonary bypass. Donor hearts were arrested and immersed in 4 degrees C St. Thomas's Hospital Solution for 4 hours. The mean total ischemic time was 323 minutes (range, 298 to 345 minutes). In the Fluosol group, 200 ml of oxygenated Fluosol (37 degrees C; PO2 650 mm Hg; PCO2 35 mm Hg) was infused into the aortic root at approximately 100 ml/min just before aortic unclamping. Coronary sinus blood was analyzed for the MB fraction of creatine kinase, reduced glutathione, and oxidized glutathione. Hemodynamic and biochemical results were obtained at 30 minutes, 1 hour, and 3 hours after bypass. In the control group, during the second 30 minutes of the period after bypass, left ventricular end-diastolic pressure and stroke volume showed progressive deterioration, 54.8% increased (p less than 0.01) and 28.4% decreased (p less than 0.05), respectively. The MB fraction of creatine kinase and oxidized glutathione were increased, and reduced glutathione had declined, from 39.3 to 135.3 IU/L (p less than 0.01), from 28.0 to 33.4 micrograms/ml (p less than 0.05) and from 4.4 to 2.5 micrograms/ml (p less than 0.01), respectively. These parameters failed to recover during the next 2 hours, and massive mitochondrial degeneration was observed by electron microscopy. In the Fluosol group, these parameters maintained their baseline values, and electron microscopy showed well-preserved mitochondria. The data suggested that, in the control group, initial mitochondrial dysfunction was profound, persistent for at least 3 hours, and associated with membrane hyperpermeability, leading to cardiac dysfunction. Oxygenated Fluosol perfusion better preserved cardiac and mitochondrial function.

Animals↗
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A phase II multicentric trial of S-1 combined with 24 h-infusion of cisplatin in patients with advanced gastric cancer.

BACKGROUND: The aim of this multicentric trial was to determine the clinical toxicities and antitumor effects of a chemotherapy regimen of S-1 combined with cisplatin in patients with inoperable locally or metastatic advanced gastric cancer. PATIENTS AND METHODS: Forty-two patients were entered into the study. S-1 (80 mg/m2) was administered orally daily for 14 consecutive days and 24-h infusion of cisplatin (70 mg/m2) was administered on day 8 of every 28-day cycle. RESULTS: The overall response rate was 50% and complete response rate was 5%. The most common adverse event was leucopenia, which occurred with grade 3 in 7 patients (16.6%) and grade 4 in 2 patients (4.8%). Non-hematological adverse events were generally mild. The median survival time was 342 days. The 2-year survival rate was 22.9%. CONCLUSION: This combination chemotherapy is active, convenient and well tolerated in patients with high-grade advanced gastric cancer.

Adult↗
PubMedDate not supplied

Miniature membrane oxygenator for use in neonatal ECMO.

A new miniature membrane oxygenator (Kuraray KMO, size, 0.3 m2, with a priming volume of 47 ml, compliance of less than 0.1 ml/100 mmHg, and pressure loss of 45 mmHg) with improved gas transfer and mechanical durability was developed and tested. The membrane material is a hollow fiber double layer polyolefin. The testing procedures determined by the AAMI were followed, and the results showed improved O2 and CO2 transfer (70 ml/min and 55 ml/min, respectively). Hemolysis was within acceptable limits, and plasma leakage was undetectable after 7 days of perfusion. Clinical study demonstrated satisfactory performance.

Carbon Dioxide↗
PubMedDate not supplied

A rare case of desquamative esophagitis occurring during radiotherapy for esophageal carcinoma.

With the recent progress and increase in availability of fiberendoscopy, acute esophagitis is now much more frequently detected than before. Desquamative esophagitis is a rare form of esophagitis classified as acute esophagitis, but it has come to be reported more frequently in recent years. However, since desquamation seemed to have occurred in relation with the administration of radiotherapy in the present case, this brings to two the total number of cases with radiological involvement, the other case reported by Itai being the first in the world. This is the second report of desquamative esophagitis occurring during radiotherapy for esophageal carcinoma.

Aged↗
PubMedDate not supplied

Long-term results of arterial reconstruction of lower extremities determined by flow waveform analysis.

Arterial reconstructions of the lower extremities were reviewed to assess the usefulness of flow waveform analysis. Six hundred and thirty-four arterial reconstructions were divided into two groups: a former (1965-1973) group of 218 reconstructions not assessed by flow waveform analysis and a recent (1974-1985) group of 416 reconstructions analyzed according to flow waveform. The cumulative patency rates of the former and the recent group at 5 years were as follows: aorto-femoral, 75.2% and 86.7% (P less than 0.05); femoral-distal, 34.6% and 61.5% (P less than 0.001); extra-anatomical, 63.6% and 80.2% (P = 0.06), respectively. Based on the various flow waveforms evidenced intraoperatively, the cumulative patency rate of cases in the recent group with type 0 and I flow waveform was compared to the rate of those with type II flow waveform. The cumulative patency rates at 5 years were as follows: aorto-femoral, 92% and 82.7% (P = 0.15); femoral-distal, 77.7% and 49.3% (P less than 0.001); extra-anatomical, 91.8% and 68.9% (P less than 0.05), respectively. These results indicate that intraoperative flow waveform analysis is a simple and useful indicator for predicting the long-term results of arterial reconstruction.

Arterial Occlusive Diseases↗
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Loco-regional treatment for esophageal cancer with bleomycin adsorbed to activated carbon particles.

Bleomycin (BLM) was adsorbed to activated carbon particles (BLM-CH), and the effective distribution of BLM in the regional lymph nodes and surrounding connective tissues was studied in 10 patients with mid-thoracic esophageal cancer. One ml of BLM-CH was injected submucosally into the tumor and normal esophageal wall endoscopically one or three days prior to operation. BLM activity was found both in the lymph nodes and connective tissues, not only in the mediastinal region but in the cervical and abdominal regions. Degenerative or inflammatory changes were microscopically observed in 6 out of 23 lymph nodes with metastatic foci. BLM-CH could be a useful tool in targeting chemotherapy for esophageal cancer.

Adult↗
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Strategies for intractable ascites after hepatic resection: analysis of two cases.

Intractable ascites after hepatic resection is one of the gravest complications pertaining to deterioration in a patient's quality of life. Two cases are presented with intractable ascites that did not respond to ordinary conservative treatment after hepatic resection but were eventually successfully treated. The authors propose the following strategies: the conducting of aggressive and extensive examinations including angiography; and a peritoneovenous shunt for patients demonstrating no definite cause, to improve their quality of life.

Ascites↗
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Dynamic MRI with slow injection of contrast material for the diagnosis of pituitary adenoma.

Magnetic resonance (MR) imaging of pituitary adenoma is usually carried out in dynamic studies with bolus contrast material injections, with the result that few strong images are obtained. Dynamic studies using a slowly injected contrast material were carried out in 14 cases of pituitary adenomas. The examinations were performed with a 1.5 Tesla superconducting MR imaging system using the spin-echo technique. Gd-DTPA (0.1 mmol/kg) was slowly injected (within 90 sec) by hand, providing seven to nine dynamic images during 350 sec from the start of injection. The average time to reach the maximum signal intensity was 170.6 sec in adenoma and 156.2 sec in normal gland tissue. The maximum contrast signal intensity ratio of adenoma to normal gland was 0.527 in the fifth image. The contrast of adenoma to normal gland tissue was calculated by the following formula: ASII (adenoma signal intensity index) = (adenoma signal intensity-tissue signal intensity)/tissue signal intensity. The most remarkable contrast between adenoma and normal tissue was obtained from the fourth to eighth images. In other words, we could obtain the strongest contrast at 144.8 sec to 299.6 sec from the start of contrast injection. Our results with slow injection suggest that stronger images can be obtained a longer period after contrast injection.

Adenoma↗
PubMedDate not supplied

Cystic neoplasms of the liver: a report of two cases with special reference to cystadenocarcinoma.

We herein present two cases with cystic neoplasms of the liver, both successfully treated by a surgical resection. One patient underwent a tumor enucleation, while the other had a left hepatic lobectomy and left caudate lobectomy. Although the follow-up period is still relatively short, both patients are doing well without any sign of recurrence. The specimens were histopathologically examined including immunohistochemical staining. Both tumors were unilocular-cystic and contained mucus. One tumor was considered to have originated from a cystadenoma with a mesenchymal stroma, which has been espoused by Wheeler and Edmondson, while the other tumor was considered to have originated from the bile duct. Therefore, the diagnosis of one patient was cystadenocarcinoma, while the other was considered to be a mucin-producing papillary adenocarcinoma of the intrahepatic bile duct. No invasive growth to the liver parenchyma or the surrounding tissues was observed in either case. Thus, a surgical resection should be the first choice of treatment for cystic neoplasms of the liver. Furthermore, a malignant transformation of cystadenoma with a mesenchymal stroma should be given a special entity in cystadenocarcinoma.

Adenocarcinoma, Mucinous↗
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Argyrophilic nucleolar organizer regions (AgNOR) of resected intrahepatic cholangiocellular carcinomas.

BACKGROUND/AIMS: Thxe argyrophilic nucleolar organized resion (AgNOR) is loop DNA encoded for rRNA production on the nucleoli, which controls cell proliferation and protein synthesis (1,2). Based on numerous studies, it has been suggested that the AgNOR number correlates with both cellular kinetics and the malignant grade of the tumor. MATERIALS AND METHODS: The argyrophilic nucleolar organized regions (AgNOR) of 14 operated cases with intrahepatic cholangiocellular carcinoma (IHCCC) were examined. RESULTS: The number of AgNOR per nucleus (the AgNOR score) was found to be related to both the level of carcinoembryonic antigen (CEA) (r = 0.63, P = 0.016) and the size of the tumor (r = 0.62, P = 0.017). Regarding the age, sex, the presence or absence of lymph node metastasis, the grade of TNM classification, and the main location of the tumor, no statistical significance was recognized. On the other hand, both histological difference and differentiation were observed to remarkably reflect the AgNOR score (P = 0.03). The cancer-free survival and survival rate showed no relationship to the AgNOR score, but patients with an AgNOR number lower than 2.0 showed a poorer cancer-free survival rate as well as a poorer survival rate. Two patients with a long survival, who have been free from cancer for more than 5 years, showed a low AgNOR score (1.6, 1.7). CONCLUSIONS: The AgNOR method is simple, low-cost and can easily be applied to paraffin-embedded sections. Therefore, this score is considered to be useful in identifiying malignant potentiality in intrahepatic cholangiocellular carcinoma.

Aged↗
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A refined method of trans-thoracoabdominal hepatectomy for cirrhotic patients with hepatocellular carcinoma.

A hepatectomy in cirrhotic patients with hepatocellular carcinoma, located in either the posterior or superior part of the right lobe, inevitably requires a forced mobilization of the right lobe. Such a forced procedure causes a decreased hepatic blood flow resulting in postoperative morbidity and mortality, as well as an increased risk of the intrahepatic dissemination of cancer cells during the operation. We have thus refined the method of trans-thoracoabdominal hepatectomy to minimize those demerits of conventional transabdominal hepatectomies. The main characteristics of our refinements are as follows; (1) an optimal incision for the best short-cut to the hepatocellular carcinoma is determined by a three-dimensional imaging of either helical computed tomography and/or magnetic resonance imaging before operation; (2) a complete view of the operative field is obtained by the pertinent use of rotating the operation table, on which the patient is placed in a left semi-lateral position; (3) this method is suitable for resecting a tumor located in the posterior segment such as a posterior segmentectomy. This refined method is considered to decrease the postoperative morbidity including post-operative hepatic dysfunction and is also useful for cirrhotic patients with hepatocellular carcinoma.

Carcinoma, Hepatocellular↗
PubMedDate not supplied

Early recurrence after surgery of hepatocellular carcinoma.

BACKGROUND/AIMS: In 231 patients with hepatocellular carcinoma who underwent liver resection from 1986 to 1992 to determine the significance of alpha-fetoprotein (AFP) levels. MATERIALS AND METHODS: There were 13 patients (5.6 per cent) with early recurrence within six months after hepatectomy. RESULTS: Preoperative serum alpha-fetoprotein (AFP) levels were significantly higher in patients with early recurrence (p < 0.01). Postoperative histological examination revealed that there were significant correlations between patients with early recurrence and intrahepatic metastasis (p < 0.01), and portal vein infiltration (p < 0.01). There were significant correlations between patients with early recurrence and preoperative diagnosis of intrahepatic metastasis (p < 0.01), however, preoperative diagnosis of portal vein infiltration could not be detected enough. Eight (73%) of 11 patients with over 1000 ng/ml of AFP and preoperative diagnosis of intrahepatic metastasis had early recurrence (p < 0.01). CONCLUSIONS: We found that patients of hepatocellular carcinoma with over 1000 ng/ml of AFP and preoperative diagnosis of intrahepatic metastasis are the most important factors in the preoperative clinical data linked to early recurrence type of HCC after hepatectomy.

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