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Biomedical subjects

Y Ando

Publications and source records attributed to Y Ando.

At least 379 records · Page 21Linked to original sources
PubMed1995

[Two cases of post-encephalitic epilepsy characterized by auditory cognitive dysfunction; comparison with "a peculiar type of post-encephalitic/encephalopathic epilepsy"].

Two cases of post-encephalitic epilepsy mainly characterized by auditory cognitive dysfunction were reported. In acute phase they only showed slight pleocytosis of CSF, and serum antiviral antibodies were all negative. Although their seizures were partial seizures with secondary generalization, their EEG and radiographic imaging did not show any lesions. Their waking state EEG continuously showed slowing with decrease of alpha activities. After clusters of convulsions, they showed delirium and aggressiveness. Both of them were thought to have post-encephalitic epilepsy with pathogen unknown and they were compatible with "a peculiar type of post-encephalitic/encephalopathic epilepsy" reported by Fukuyama and Awaya. The presented two cases were characterized by auditory cognitive dysfunction and intractable epilepsy with secondary generalization.

Acute Disease↗
PubMed1995

[Evaluation of sleep apnea syndrome (SAS) with low field MR fluoroscopy].

Eight cases of clinically diagnosed sleep apnea syndrome (SAS) and two normal volunteers were studied with low field MR fluoroscopy in order to monitor the waking and sleeping status of the upper airway. MR fluoroscopy revealed that only the sleeping patients showed occlusions of the upper airway. This technique provided us with useful information about the level, frequency and duration of occlusion in each case. Four of the eight patients demonstrated simple retropalatal occlusion, whereas the other four demonstrated mixed retropalatal and retropalato-retroglossal occlusion. Thus long-time monitoring, which is only possible with MR fluoroscopy, is needed to appreciate the complex nature of the disease. In addition, the comfortable surroundings and low noise level provided by the low field enabled physiological study to be performed without any tranquilizers in most of the patients, which is again only possible with MR fluoroscopy. MR fluoroscopy may become a tool of great clinical value, providing much important information for disease evaluation and treatment selection.

Adult↗
PubMed1995

[Rapid detection and identification of mycobacteria by the PCR assay based on the co-amplification of the gene IS6110 and groEL].

In definite diagnosis of mycobacterial infection, prompt and adequate differential diagnosis leads to an appropriate treatment. We developed and evaluated a PCR assay based on co-amplification of the insertion sequence IS6110 and groEL gene that are species-specific for Mycobacterium tuberculosis complex and genus-specific, respectively. The detection limit of the assay system for cultured M. tuberculosis was 2 cells/ml, as compared with 200 cells/ml by culture onto Ogawa's medium. To assess the value of the assay in routine laboratory works, the results obtained by PCR were compared with those by standard microbiological methods for 758 specimens collected for the examinations of mycobacterial infection. The PCR system for detection of mycobacteria gave overall positive rate of 27.6% (209/758), as compared to 6.1% (46/758) by smear and 7.7% (58/758) by culture onto Ogawa's medium. Sensitivity and specificity were 97.8% and 97.3%, respectively, for the IS6110 and groEL gene for detection of M. tuberculosis complex; 91.7% and 80.3%, respectively, for only the groEL gene for detection of atypical mycobacteria. The PCR assay based on co-amplification of the IS6110 and groEL gene would be useful for diagnosis of mycobacterial infections, allowing not only more sensitive detection of mycobacteria but also rapid discrimination between M. tuberculosis complex and atypical mycobacteria. This assay would help to eliminate time-consuming confirmation, and to avoid both unnecessary treatment and hospitalization of the patient.

DNA, Bacterial↗
PubMed1995

[Dose-volume histogram comparison among techniques of linac stereotactic radiosurgery].

The aim of this study was to analyze the three-dimensional dose distributions produced by various techniques used in current radiosurgery treatments by means of dose-volume histograms (DVH). Off-center ratio and tissue-peak ratio from 6-MV X-rays through additional cylindrical collimators were measured in advance for dose calculation. The use of the diamond detector and beam profile film dosimetry in small fields were certified. The impact of arc number, arc geometry, and field size on the dose distribution in a spherical phantom was evaluated through the use of DVH. These were calculated for a) four arc irradiations with collimator sizes of 5, 10, 20 and 30 mm in diameter, and b) for single-plane rotation, four or eleven multiple non-coplanar convergent arcs, dynamic rotation and precessional converging radio-therapy (PCR) with a field size of 20 mm. PCR is performed in the sitting position with the patient seated on a special treatment chair, which is rotating continuously while the gantry moves from the top to the center of the chair rotation. Most of the differences between techniques were found in a range of less than 40% of the maximum dose. Multiple non-coplanar convergent arcs with four or eleven arcs and PCR performed similar result in DVH, while single-plane rotation revealed almost unacceptably shallow dose falloffs. The DVH of dynamic rotation was between that of single-plane rotation and the other three methods.

Humans↗
PubMed1995

IS&C (Image Save & Carry) standard: standardized exchange media for medical information.

There has been a strong need for a standardized medical image exchange media. MEDIS-DC in Japan created IS&C as a standard for this purpose, based on 5.25' rewritable magneto-optic discs, with many specifications such as fast speed read/write, independence of apparatus vendor, additional security features, and data format compatible to ACR-NEMA v.2 image format. IS&C is already applied to many institutions, as an alternative for fast expensive networks, long term image casebases and media for teaching file distribution. The IS&C committee hopes this standard will be: 1) used at clinics and hospitals, promoting exchange of information between them, 2) harmonized with other standardization activities, and 3) a basis for future electronic semantic medical records.

Computer Communication Networks↗
PubMed1995

Evaluation of bi-level image converting methods for nuclear medicine image database stored in the IS&C magneto-optical disk.

1. INTRODUCTION. We have developed a report and imaging management system for nuclear medicine. The report and image data are stored in the IS&C magneto-optical disk (IS&C MOD). Nuclear medicine image data are relatively small, but they are large enough to create problems when being transported over a low-speed Hospital Information System (HIS) network. Moreover, gray scale image output devices (i.e., high-resolution displays, sonoprinters) are expensive. If high quality bi-level (black and white) images were available, images could be transferred through low-speed network with inexpensive bi-level terminals or conventional page-printers. We examined images using several bi-level image conversion techniques [1, 2] in order to determine how useful the bi-level images are and to assess their suitability for use in nuclear medicine. The images were compared with original film images by ROC analysis. The modified minimized average error method was found to be superior to other methods in bone and gallium images. Its A-values are 0.83 in gallium scan and 0.85 in bone scan. 2. MATERIALS AND METHODS. Our system consists of three digital gamma cameras, a nuclear medicine data processing unit, two UNIX stations, and two personal computers. The computers and the data processing unit are connected via Ethernet and each computer has an IS&C MOD unit. Image and report data are stored in the IS&C MOD. The computers are also connected off-line through the IS&C MOD. To evaluate image quality, bone scan images and gallium scan images (1024x512, 2048x1024 pixels and 16 bits depth) were converted to bi-level images (same pixels and one bit depth) using four methods: dither method, minimized average error method (MAE)[1], modified regional adaptation method, and constrained average method. For the dither methods, three sets of dither matrix (Fatting's, Bayer's and our original matrix) were employed. The computer images were compared with original film images by ROC analysis. 3. RESULTS. The converted bi-level images were 1/16 the size of the originals. They were transferred via Ethernet, displayed on the monochrome display, and printed using a conventional page-printer (240 dpi or 300 dpi). The A-values of the original gallium and bone images on the films were 0.89 and 0.94. Modified MAE method gave better results than other methods tested, with the gallium image using this technique reading 0.83 on the A-scale; and the bone images were 0.85. 4. DISCUSSION. Generally, nuclear medicine images require lower spatial and gray level resolution than other computer imaging techniques. We compared four bi-level image conversion methods in order to know which methods are suitable to nuclear medicine images. The ROC analysis was employed to evaluate these image qualities. The MAE methods made particular texture pattern as artifacts in the intermediate gray level area. But it can express homogeneity the neutral level. The dither method images are coarse texture. It affects detectabilities of subtle abnormal findings. 5. CONCLUSIONS. The A-z values of the modified MAE images were comparable to those of original film images. Although bone images give slightly lower values, many abnormal findings can be ascertained on bi-level images. High quality bi-level image techniques are considered to be useful for nuclear medicine image database systems.

Japan↗
PubMed1995

Development of a personal computer's viewing station for the IS&C magneto-optical disk.

We developed a display station for the medical images stored in the IS&C (Image Save and Carry) magneto-optical disk. This station consisted of the personal computer and the magneto-optical disk drive. The performance of this system was evaluated and was compared with the Unix workstations. We found that the personal computer system had an adequate ability to display medical images. It provided, moreover, for portability and practical use of medical information.

Data Display↗
PubMed1995

Combination treatment with interferon alfa-2b and ribavirin for chronic hepatitis C in patients who have failed to achieve sustained response to interferon alone: Swedish experience.

BACKGROUND: Only 10-20% of patients treated with interferon alfa alone attain long-term benefits. More effective regimens are needed. METHODS: Twenty Swedish patients with chronic hepatitis C virus infection, ten with a prior non-response and ten with a non-sustained response to interferon alfa treatment alone, were treated with interferon alfa-2b and ribavirin in combination for 24 weeks, then followed up for another 24 weeks. Patients received interferon alfa-2b subcutaneously 3 MU thrice weekly and oral ribavirin 1000-1200 mg/day. RESULTS: All ten patients with a prior non-sustained response to interferon alone had a sustained biochemical response with normal aminotransferase levels at follow-up; nine also had a sustained viral response with a negative HCV-RNA test in serum. Among the ten patients with a prior biochemical non-response to interferon alone, five had normal aminotransferase levels at the end of therapy; four were negative for HCV RNA in serum. At follow-up, three had normal aminotransferase levels and a negative HCV-RNA test in serum. No major adverse effect was seen, apart from fatigue and an expected fall in hemoglobin levels from a mean of 155 g/l to 124 g/l at the end of therapy. All patients completed the treatment schedule, but the ribavirin dose was reduced in one patient because of a fall in hemoglobin to 99 g/l. CONCLUSIONS: These results indicate that combination treatment with interferon alfa-2b and ribavirin offers a chance of sustained biochemical response and virus eradication in a subset of patients who fail to achieve sustained response with interferon alfa alone.

Adult↗
PubMed1995

[Familial amyloidotic polyneuropathy (FAP) type I and the therapies].

Since autonomic dysfunction in familial amyloidotic polyneuropathy (FAP) Type I is recognized in the early stage of FAP patients and restricts their daily life, we developed various therapies for various autonomic manifestations: Loading glucose was often effective for faintness caused by hypoglycemia and erythropoietin was also good therapy for orthostatic hypotension as well as anemia found in the end stage of FAP patients. Stoma and nasal drop of L-threo-DOPS were useful to control diarrhea and orthostatic hypotension. Duplex ultrasonography of the 4 vessels revealed that reverse flow was always recognized in FAP patients with faintness, which was effectively treated by the administration of L-threo-DOPS. Orthotopic liver transplantation revealed effective therapy for autonomic dysfunction in FAP patients. Precise analysis of protein metabolism in FAP patients revealed that among apolipoproteins, only apolipoprotein AII decreased as the progression of the disease and high density lipoprotein gained the negative charge by agarose electrophoresis study. Concerning low density lipoprotein (LDL) study, only variant transthyretin in the circulation associated with LDL in FAP patients, suggesting that LDL may play an important role in the amyloid formation of FAP.

Amyloid Neuropathies↗
PubMed1995

Primary adenosquamous carcinoma of the colon.

A case of primary adenosquamous carcinoma of the colon in a 73-year old woman is reported. Primary adenosquamous carcinoma of the colon is rare, and follows more highly aggressive course. But this case was successfully resected with prolonged survival. The pertinent literature is reviewed.

Aged↗
PubMed1994

Decrease in Cu/Zn- and Mn-superoxide dismutase activities in brain and spinal cord of patients with amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is a degenerative disorder of motor neurons in the central nervous system (CNS). Mutation of the Cu/Zn-superoxide dismutase (SOD) gene on chromosome 21 has been found in some families with autosomal dominant familial ALS (FALS). We sought to determine whether there may be differences in the distribution and activity of SOD in the CNS of patients with sporadic ALS, and of control patients without neurological disorders. The frontal cortex, cerebellum, and spinal cord were obtained at autopsy on 5 patients with ALS and from 10 controls. Immunohistochemically, in the controls, the cytosols of the large pyramidal neurons of the cerebral cortex, anterior and posterior horn cells, and neurons of the nucleus thoracicus of spinal cord were stained homogeneously with anti-human Cu/Zn-SOD antibody, and in a granular manner with anti-human Mn-SOD antibody. Pia mater and epithelial cells of choroid plexus also stained well. Conversely, in the CNS of the ALS patients, most neurons were stained faintly, or not at all with both anti-Cu/Zn- and Mn-SOD antibodies, whereas the pia mater and the epithelial cells of choroid plexus stained intensely. There was no difference in total SOD activity in the entire CNS between ALS patients and controls, as determined by enzyme assay. Results suggest that, in cases of sporadic ALS, the activities of Cu/Zn- and Mn-SOD are decreased and superoxide produced within the neurons accumulates because of an insufficient elimination, leading to the development or acceleration of cell damage, ultimately producing neuronal degeneration and necrosis.

Adolescent↗
PubMed1994

Role of nitric oxide in the peripheral vessels of patients with familial amyloidotic polyneuropathy (FAP) type I.

In order to establish the generation of endothelial derived relaxating factor (EDRF) in patients with familial amyloidotic polyneuropathy (FAP) type I, the muscle temperature of the lower limb was measured with a deep portion thermometer. The temperature of the gastrocunemius muscle in FAP patients was significantly decreased compared with control subjects. In order to investigate the generation of EDRF in FAP patients, we administered NG-monomethyl-L-arginine (L-NMMA), specific inhibitor of nitric oxide, from the brachial artery and measured the changes in blood flow. Although 61.7 +/- 18.2% of the blood flow was transiently decreased after administration of L-NMMA in control subjects, FAP patients showed poor responses. In contrast, in the same way as in control subjects, significant vasodilatation was seen in FAP patients after administration of L-arginine. The urinary secreted NO2-/NO3- levels per day, which reflect the synthesis of nitric oxide in the systemic circulation, was a great deal lower in FAP patients than in control subjects. These results suggest that, although peripheral vessels can be dilated when a large amount of the substrate for NO synthase, L-arginine, is supplied, production of nitric oxide may be suppressed, and, as the result of this phenomenon, blood flow is decreased in the peripheral tissues of FAP patients in a static state.

Adult↗
PubMed1994

Role of superoxide dismutase and nitric oxide on the interaction between brain and systemic circulation during brain ischemia.

To elucidate the critical role of superoxide dismutase (SOD) and nitric oxide in brain injury and systemic circulation during brain ischemia, we performed bilateral carotid artery ligation (BCAL) on rats and evaluated the effects of NG-monomethyl-L-arginine (L-NMMA) and a long-acting SOD derivative (SMA-SOD). After administration of L-NMMA, specific inhibitor against nitric oxide synthase (NOS), most of BCAL rats died within 6 h while no BCAL rats without L-NMMA died at all. Administration of SMA-SOD exhibited no effect on the life span of BCAL rats. Magnetic resonance imaging (MRI) and microscopic analysis for the ischemic brain revealed that, although administration of L-NMMA showed no significant effect on the ischemic brain of BCAL rats, SMA-SOD effectively prevented the ischemic changes based on permeability edema in the frontal lobe. Measurement of changes in the blood flow of the ischemic brain revealed that administration of L-NMMA decreased the blood flow in the BCAL rats while no remarkable changes were seen after administration of SMA-SOD. Urinary secretion of NO2-/NO3-, the metabolites of nitric oxide, was increased by challenging BCAL, and the presence of L-NMMA or SMA-SOD diminished this elevation. Blood pressure was increased by performing BCAL to rats, and administration of L-NMMA showed further elevation of the blood pressure. On the contrary, administration of SMA-SOD decreased post-ischemic hypertension. These results suggest that SOD may play a protective role for brain ischemia by suppressing increased vascular permeability, while nitric oxide showed beneficial effect on the ischemic brain by increasing the blood flow in the ischemic brain.

Amino Acid Oxidoreductases↗
PubMed1994

The gene responsible for LEC hepatitis, located on rat chromosome 16, is the homolog to the human Wilson disease gene.

We identified the rat homolog to the human Wilson disease (WD) gene as the gene responsible for hepatitis (hts) in the Long Evans Cinnamon (LEC) rat. A genetic study using fifty-three backcross progenies showed that the rat WD gene detected by Southern blotting using the human WD gene as a probe was tightly linked to the hts phenotype of the LEC rat with no recombination. LEC is a transcriptionally deficient mutant because no transcript of the rat WD gene could be found in the LEC rat by Northern blotting. This rat WD gene was mapped to 16q12.23-12.3 by fluorescence in situ hybridization and mouse x rat somatic cell hybrid analysis.

Animals↗
PubMed1994

[Parallel processing of dose calculation for external photon beam therapy].

We implemented external photon beam dose calculation programs into a parallel processor system consisting of Transputers, 32-bit processors especially suitable for multi-processor configuration. Two network conformations, binary-tree and pipeline, were evaluated for rectangular and irregular field dose calculation algorithms. Although computation speed increased in proportion to the number of CPU, substantial overhead caused by inter-processor communication occurred when a smaller computation load was delivered to each processor. On the other hand, for irregular field calculation, which requires more computation capability for each calculation point, the communication overhead was still less even when more than 50 processors were involved. Real-time responses could be expected for more complex algorithms by increasing the number of processors.

Mathematical Computing↗