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Biomedical subjects

K Terada

Publications and source records attributed to K Terada.

At least 145 records · Page 8Linked to original sources
PubMed1997

Evaluation of an automatic-mode image processing method in chest computed radiography.

RATIONALE AND OBJECTIVES: The automatic image processing mode of the storage phosphor computed radiography system was evaluated. MATERIALS AND METHODS: A dedicated chest unit designed for erect view was used to examine a chest phantom. Lucite plates 1, 2, and 3 cm thick that conformed to the shape of the lung were attached to the phantom, and images were obtained in automatic and manual image processing modes. The changes in the optical density of the lung, rib, and heart and the changes in contrast were measured. The degree of diffuse opacity due to the plates and the visibility of superimposed simulated nodular and honeycomb opacities were evaluated. RESULTS: The decrease in optical density and contrast caused by increasing thickness of the Lucite plates was less pronounced in the automatic mode compared with the manual mode. When plates were placed only on the right lung, the optical density and the contrast on the contralateral side either increased or remained unchanged with the automatic mode. The degree of diffuse opacity was rated higher in the manual mode, and the visibility of superimposed simulated opacities was considered relatively constant in the automatic mode. CONCLUSION: The automatic image reading mode used in the computed radiography chest system may mask the detection of abnormalities such as diffuse homogeneous lung opacity.

Evaluation Studies as Topic↗
PubMed1997

Isolation of oval cells from Long-Evans Cinnamon rats and their transformation into hepatocytes in vivo in the rat liver.

Oval cells function as compensatory cells in severe liver injury and are thought to be equivalent to liver stem/progenitor cells. We isolated oval cells from the liver of Long-Evans Cinnamon (LEC) rats by isopyknic centrifugation in a Percoll gradient. The cells were gamma-glutamyl transpeptidase (GGTP)-positive, alpha-fetoprotein-positive, and cytokeratin (CK) 18- and CK 19-positive, but albumin-negative in the cells. When oval cells were transplanted to the liver, they were transformed into hepatocytes. To evaluate albumin biosynthesis, we transplanted oval cells into the liver of Nagase analbuminemic and LEC double mutant rats. The albumin level in the serum of transplanted rats was increased and maintained for up to 10 weeks. These results indicated that the oval cells isolated from LEC rats can differentiate into hepatocytes in vivo.

Albumins↗
PubMed1997

HSDJ, a human homolog of DnaJ, is farnesylated and is involved in protein import into mitochondria.

The role of HSDJ, a human homolog of bacterial DnaJ and yeast YDJ1p/MAS5, in mitochondrial protein import was examined. Recombinant HSDJ was purified and an antibody was prepared. HSDJ mRNA was heat-induced in cultured cells. In pulse-labeling and chase experiments using COS-7 cells, the endogenous HSDJ homolog was prenylated. Transiently expressed HSDJ was also prenylated, whereas its mutant C394S in which cysteine of the "CaaX box" was mutated to serine, was not. HSDJ, but not C394S, synthesized in rabbit reticulocyte lysate was farnesylated. The HSDJ antibody inhibited import of ornithine transcarbamylase precursor (pOTC) into isolated mitochondria when added prior to pOTC synthesis, but not when added prior to import assay. In transient expression of pOTC in COS-7 cells, pOTC was synthesized and processed to the mature form with an apparent half-life of 2-3 min. Coexpression of HSDJ or C394S resulted in slight retardation of the pOTC processing. These results indicate that HSDJ is involved in an early step(s) of protein import into mitochondria.

Animals↗
PubMed1997

Event-related potentials associated with judgment: comparison of S1- and S2-choice conditions in a contingent negative variation (CNV) paradigm.

To elucidate the functional role of association cortex in judgment and decision-making about external stimuli, the scalp topography of contingent negative variation (CNV) recorded in 9 normal volunteers was compared in two settings; dichotomous S1- and S2-choice paradigms using right wrist extension or flexion movement upon S2 as the choice reaction task with an S1-S2 interstimulus interval of 2 s. Two main findings were obtained. First, early CNV in the S1-choice paradigm consisted of a frontal to frontopolar midline negative potential, most likely representing judgment more than orienting response, and a left-sided parietal positive potential, at least partially representing P3b, whereas in the S2-choice paradigm it consisted only of a smaller frontal negative potential shift, most likely representing merely an orienting response. This suggests that the prefrontal and left parietal association cortexes might be active in the judgment and decision-making process. Second, after S2, two positive peaks (334 and 545 ms after S2) were observed at the midline central to left parietal areas only in the S2-choice paradigm. In the S1-choice paradigm, one large negative peak (275 ms after S2) was observed. We postulate that the first peak of the S2-choice paradigm is related to decision making or judgment and that the second peak is related to the following cognitive process. We conclude that at least the prefrontal and parietal association cortexes generate transient potentials accompanying judgment, and possibly decision making.

Adult↗
PubMed1997

Frontopolar ictal epileptiform discharges on scalp electroencephalogram in temporal lobe epilepsy.

We report 3 patients with medically intractable complex partial seizures (CPS) arising from the temporal lobe judged by surgical outcome, in whom scalp electroencephalogram (EEG) showed ictal epileptiform discharges at the frontopolar region. In all patients, results of cranial magnetic resonance imaging (MRI), positron emission tomography (PET), and ictal single photon emission computed tomography (SPECT) were consistent with those of temporal lobe epilepsy (TLE). The epileptogenic area was defined in the temporal lobe by chronic subdural recording in 2 patients. After surgical treatment (amygdalohippocampectomy, anterior temporal lobectomy, and temporal lesionectomy, respectively), all 3 patients became seizure-free and the interictal frontopolar epileptiform discharges on scalp EEG disappeared. Patients with TLE may show ictal scalp EEG with frontopolar onset. This is most likely explained by direction of dipolar orientation of epileptiform discharges in 1 of our patients; rapid spread of ictal activity to the frontopolar area can also be considered in the 2.

Adult↗
PubMed1997

Epilepsy in peroxisomal diseases.

PURPOSE: To clarify the electroclinical manifestation of epileptic seizures and the evolution of epilepsy in patients with peroxisomal diseases. METHODS: Retrospective review of the medical records and EEGs of 14 patients with peroxisomal diseases: seven with Zellweger syndrome (ZS), two with neonatal adrenoleukodystrophy (NALD), two with acyl-CoA oxidase deficiency (AOXD), two with bifunctional enzyme deficiency (BFED), and one with rhizomelic chondrodysplasia punctata (RCDP). The diagnoses were made by biochemical analysis and pathological examinations in our laboratory. RESULTS: Patients manifested serious neurologic deficits in the neonatal period or in early or late infancy. Patients with ZS or AOXD had partial motor seizures originating in the arms or legs or corners of the mouth. Their seizures did not culminate in generalized tonic-clonic seizures and were easily controlled by antiepileptic drugs (AEDs). Interictal EEGs of the patients with ZS showed infrequent bilateral independent multifocal spikes, predominantly in the frontal motor cortex and its surrounding regions. The EEGs of patients with AOXD showed interictal fast theta activity, predominantly in the frontocentral regions. Patients with BFED also had partial motor seizures in early infancy, but the seizures were intractable, evolving in one case to myoclonic seizures. Interictal EEGs of patients with BFED showed bilateral independent multifocal spikes that evolved to bilateral diffuse high-voltage slow waves in one case and to a hypsarythmic pattern in another case as the disease progressed. Patients with NALD had intractable tonic seizures or epileptic spasms. Interictal EEGs showed high-voltage slow waves and bilateral independent multifocal spikes, evolving in one patient to a flat pattern. The patient with RCDP, whose interictal EEGs showed frequent multifocal independent spikes, did not have epileptic seizures. CONCLUSIONS: The age of epilepsy onset or the duration of survival is related to the types of seizures occurring in patients with peroxisomal diseases. Neonates or young infants usually have partial motor seizures (facial twitching or clonic convulsions of the arms or legs) of various multifocal origins. Older infants may have generalized seizures at the onset of the disease or evolutionally. Seizure intractability is usually less severe in patients with ZS or AOXD than in patients with NALD or BFED. There is no relation between the electroclinical characteristics of epilepsy and the genetic complementation groups in peroxisomal diseases.

Acyl-CoA Oxidase↗
PubMed1997

Subdural recording of Bereitschaftspotential is useful for functional mapping of the epileptogenic motor area: a case report.

A 26-year-old man with intractable focal motor seizure beginning with tonic contraction of the left orbicularis oculi muscle had prolonged EEG monitoring with subdural grid electrodes placed over the right perirolandic cortex. Electrical stimulation of the cortex with implanted subdural electrodes showed a relatively low threshold for afterdischarges (ADs) but could not disclose the motor area for the left upper face where or near where the epileptogenic area was expected to be present. Bereitschaftspotential recorded from the subdural electrodes in association with self-paced voluntary blink (eyelid closing) disclosed the motor area specifically related to voluntary movements of the left upper face, which was most likely buried in the sulcus. This observation suggests that recording of Bereitschaftspotential from subdural electrodes is useful for mapping the motor cortex, especially in patients with focal motor seizure with low threshold for ADs to electric stimuli.

Adult↗
PubMed1997

"Cavernous sinus EEG": a new method for the preoperative evaluation of temporal lobe epilepsy.

PURPOSE: In presurgical evaluation of temporal lobe epilepsy (TLE), invasive methods are necessary if results of various noninvasive methods are not sufficiently convergent enough to identify the epileptogenic area accurately. To detect the epileptiform discharges originating specifically from the mesial temporal lobe, we applied the cavernous sinus catheterization technique. METHODS: We placed Seeker Lite-10 guide wire electrodes into bilateral cavernous sinus through the internal jugular veins to record EEG (cavernous sinus EEG) in 6 patients with intractable TLE. Scalp EEG was simultaneously recorded in all 6 and electrocorticogram (ECoG) was also recorded in 4. RESULTS: The cavernous sinus EEG demonstrated clear epileptiform discharges, sometimes even when they were absent on the simultaneously recorded scalp EEG. The epileptiform discharges recorded from the cavernous sinus electrodes were specifically associated with those in the mesial temporal region on ECoG. Ictal EEG pattern originating from mesial temporal lobe was also clearly documented on the cavernous sinus EEG. CONCLUSIONS: This new, semi-invasive method of identifying epileptogenic areas can detect the epileptiform discharges specifically arising from the mesial temporal lobe; it is as useful as or complements the invasive techniques such as foramen ovale or depth recording.

Adolescent↗
PubMed1997

Change of the microstructure of microcrystalline cellulose with grinding and compression.

The microstructure of microcrystalline cellulose was investigated by use of a radial distribution function (RDF) based on the intensity of X-ray scattering data. Changes in the microstructure of the cellulose as a result of grinding and compression were detected by use of the RDF. The RDF of intact microcrystalline cellulose had peak maxima corresponding to distances of approximately 1.5, 2.6, 5.0, 8.2, 13.3 and 17.0 A. The first two corresponded to the intramolecular atomic distances; other peaks were attributable to the intermolecular (inter-fibre) atomic distance. Changes in the RDF as a result of grinding indicated that the regular intermolecular atomic arrangement was gradually lost. Compression resulted in formation of long-range (> 20 A) ordering of the intermolecular (inter-fibre) atomic arrangement. These results show that RDF analysis is suitable for monitoring changes in the structure of microcrystalline cellulose which occur as a result of grinding and compression.

Cellulose↗
PubMed1997

[A case of hemolytic uremic syndrome documented co-infection of vertoxin producing Escherichia coli O157 and other pathogens].

We reported a case of a 3-year-old girl with hemolytic uremic syndrome (HUS), which showed hemolytic anemia (Hemoglobin 8.2 g/dl, lactate dehydrogenase 1277 IU/l and total bilirubin 0.6 mg/dl), small purpura on the skin (platelet 7.3 x 10(4)/microliter) and slightly decreased output of urine (creatinine 0.4 mg/dl and blood urea nitrogen 27.2 mg/dl). Verotoxin producing Escherichia coli (E. coli) O157 was not isolated, but Salmonella agona and E. coli O125, which is one of the enteropathogenic E. coli, were detected from her stool culture. However, the IgM antibody against verotoxin producing E. coli (VTEC) O157 lipopolysaccharide was detected in both serum of the acute and convalescent phase by immunoblot assay. In addition verotoxin DNA was demonstrated in the stool by PCR method. Therefore, we think this HUS might be due to VTEC O157, which must have been co-infected with Salmonella agona and E. coli O125. There have been four cases including the present case of co-infection with VTEC O157 so far, and the other three cases were of the Salmonella species. Although the reason of co-infection was unknown, we may infer that food might be contaminated with some pathogens including Salmonella species or that these patients might be already infected with Salmonella species prior to VTEC infection. Even when some other pathogens were detected by a stool culture from a patient with HUS, we should pay attention to demonstrate associated of VTEC and HUS by the specific antibodies and PCR for verotoxin DNA.

Child, Preschool↗
PubMed1997

A remote conference system for image diagnosis on the World-Wide Web.

OBJECTIVE: The World-Wide Web on the Internet enables an exchange of multimedia information among remote desktop computers. Therefore, a teleradiology system using the Web would allow remote consultation with expert radiologists. Our objective was to establish a Web-based prototype system for image interpretation. CONCLUSION: Our system allows a physician to transmit clinically useful images to an expert radiologist at a different location, who can see them on a Web browser and discuss diagnoses with the physician.

Computer Communication Networks↗
PubMed1997

Gene amplification of int-2 and erbB in human esophageal cancer: relationship to clinicopathological variables.

Gene amplification is a relatively frequent event in human malignant tumors and is believed to play an important role in tumor progression. The int-2 and erbB genes are amplified more frequently than any other genes in human esophageal cancer. In order to investigate the correlation between these two proto-oncogenes and the clinical behavior of esophageal cancer, we examined DNA amplification of int-2 and erbB and analyzed their relationship to clinicopathological variables. Genomic DNA was extracted from 21 esophageal squamous carcinomas and normal esophageal mucosa, as well as from 4 metastatic tumors. We used Southern blot analysis for detection of gene amplification. Amplification of int-2 was observed in 13 of 21 cases (62%) and in all the metastatic tumors (4/4; 100%). We found a significant correlation between amplification of int-2 and the length of the primary lesion. Amplification of erbB was detected in 3 of 18 patients (17%). All patients who showed amplification of erbB also demonstrated amplification of int-2. These results suggest that amplification of int-2 or neighboring genes on 11q may participate in tumor progression and metastasis in patients with esophageal squamous cancer.

Age Factors↗
PubMed1997

[Angle of defect on 123I-MIBG myocardial SPECT].

The quantitative assessment of infero-posterior defect on 123I-metaiodobenzylguanidine (MIBG) myocardial scintigraphy was studied in 150 patients with non-ischemic heart diseases at rest. The bull's eye map, obtained from the SPECT images at 4 hours after MIBG injection, was evaluated by generating the blacked out map which exhibits regions with reduced % uptake under mean-2 SD of 13 normal controls. The blacked out regions involved infero-posterior segments and were closely resembled to the sector form. The central angle of this sector, which was named as angle of defect (AOD), significantly correlated with both the heart-to-mediastinum activity ratio (H/M) and the myocardial clearance of MIBG. Because H/M and clearance are widely used as quantitative indices in MIBG myocardial scintigraphy, these results indicate that AOD can also be used as a quantitative index of abnormal cardiac sympathetic nervous function, which is likely to appear in infero-posterior regions in non-ischemic cardiac diseases.

3-Iodobenzylguanidine↗
PubMed1997

[Importance of the delayed 123I-BMIPP image for detecting myocardial metabolic abnormality induced by transient myocardial ischemia: a case of vasospastic angina].

We experienced a case of 64-year-old man with stunned myocardium caused by vasospasm. Without enzymatic evidence of an acute myocardial infarction, the patient developed a prolonged chest pain with ST elevation in the electrocardiogram in the midnight before the day of coronary angiography. Coronary angiogram revealed no significant stenosis and left ventriculography demonstrated akinesis in the apico-anteroseptal region. Although initial images of 123I-BMIPP myocardium SPECT showed no significant decrease of uptake, delayed images revealed marked decrease of tracer uptake in the apico-anteroseptal region in which left ventriculography showed abnormal wall motion. After 3 months of medication, left ventriculography disclosed a marked improvement, and coronary spasm was evoked in the proximal portion of left anterior descending artery after intracoronary ergonovine provocations. At the same time, both initial and delayed images of 123I-BMIPP myocardial SPECT showed no significant decrease of tracer uptake. This patients was considered as a noteworthy case to understand the kinetics and metabolism of 123I-BMIPP in stunned myocardium.

Angina Pectoris↗
PubMed1997

[Evaluation of 123I-MIBG clearance from the myocardium; comparison of two methods--SPECT & planar methods].

In 123I-metaiodobenzylguanidine (MIBG) scintigram, MIBG clearance from the heart is used to evaluate the severity of various heart diseases. There are two methods for calculating MIBG clearance. One involves planar images (planar method) and the other uses a bull's eye map (SPECT method). In 158 patients and 10 normal subjects, we compared these two methods. Fifteen minutes and 4 hours after intravenous injection of 111 MBq MIBG, planar images and SPECT images were obtained. Then clearance from the heart was calculated by each method. Abnormal increase was defined as present if clearance was more than the mean + standard deviation of 10 normal subjects. Then, we examined the sensitivity with which each method could detect clearance abnormality in 158 patients. Thirty-two patients showed abnormality only on SPECT images, while planar images alone showed abnormalities in only 5 patients. The reason the SPECT method was more sensitive than the planar method may be as follows; in the case of decreased MIBG clearance from the lung, for example, in congestive heart failure, clearance by planar method is apparently decreased. Thus, the SPECT method can detect clearance abnormality more sensitively than the planar method, and if we evaluate MIBG clearance from the heart by the planar method, we must take into account MIBG clearance from the lung.

3-Iodobenzylguanidine↗
PubMed1996

Molecular cloning of cDNA for nonhepatic mitochondrial arginase (arginase II) and comparison of its induction with nitric oxide synthase in a murine macrophage-like cell line.

Arginase exists in two isoforms. Liver-type arginase (arginase I) is expressed almost exclusively in the liver and catalyzes the last step of urea synthesis, whereas the nonhepatic type (arginase II) is expressed in extrahepatic tissues. Arginase II has been proposed to play a role in down-regulation of nitric oxide synthesis. A cDNA for human arginase II was isolated. A polypeptide of 354 amino acid residues including the putative NH2-terminal presequence for mitochondrial import was predicted. It was 59% identical with arginase I. The arginase II precursor synthesized in vitro was imported into isolated mitochondria and proteolytically processed. mRNA for human arginase II was present in the kidney and other tissues, but was not detected in the liver. Arginase II mRNA was coinduced with nitric oxide synthase mRNA in murine macrophage-like RAW 264.7 cells by lipopolysaccharide. This induction was enhanced by dexamethasone and dibutyryl cAMP, and was prevented by interferon-gamma. Possible roles of arginase II in NO synthesis are discussed.

Amino Acid Sequence↗
PubMed1996

Tortuosity of the vertebral artery in patients with cervical spondylotic myelopathy. Risk factor for the vertebral artery injury during anterior cervical decompression.

STUDY DESIGN: The case report presented herein shows tortuosity of the vertebral artery in a patient with cervical myelopathy. This case led the authors to evaluate 22 other patients who also had undergone anterior cervical fusion. They were studied before operation by either magnetic resonance imaging angiography or selective vertebral angiography. OBJECTIVES: To analyze the radiographs, computed tomography, magnetic resonance imaging, and angiography findings to detect any tortuosity of the vertebral artery in patients with cervical myelopathy to show the risk factors of vertebral artery injury during anterior decompression. SUMMARY OF BACKGROUND DATA: Complications of vertebral artery laceration during cervical anterior decompression are rare, so this injury and abnormality in the course of vertebral artery in patients with cervical myelopathy receive little attention. METHODS: The tortuosity of the vertebral artery was assessed by angiography, magnetic resonance imaging, and computed tomography. RESULTS: Mild vertebral artery tortuosity was observed in 10 patients and loop formation in three associated with cervical spondylotic changes. CONCLUSIONS: This study suggests that vertebral artery loop formation is developed associated with cervical spondylotic changes. During the anterior decompression of cervical spondylotic myelopathy or radiculopathy, the looped vertebral artery could be injured by an excessive wide rejection of the bone or disc material. In the case of vertebral artery migration, the looped vertebral artery can even be injured by routine procedures.

Adolescent↗