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Biomedical subjects

T Momose

Publications and source records attributed to T Momose.

At least 73 records · Page 4Linked to original sources
PubMed1997

Metabolism of technetium-99m-L,L-ethyl cysteinate dimer in rat and cynomolgus monkey tissue.

UNLABELLED: Technetium-99m-L,L-ethyl cysteinate dimer (99mTc-ECD) is thought to be hydrolyzed in the brain by an enzyme and to be trapped as a hydrophilic product. We investigated the characteristics of the enzymatic system that metabolizes 99mTc-ECD. METHODS: In 50 mM phosphate buffer (pH 7.4), 99mTc-ECD was incubated with various concentrations of homogenates of rat tissues (blood, liver and brain) or cynomolgus monkey tissues (blood, liver, cerebral gray matter, cerebral white matter and cerebellar gray matter), and the metabolic rates were assessed. Inhibition studies were performed using diisopropyl fluorophosphate, eserine and p-chloromercuribenzoate as inhibitors. The metabolic rates in the brain homogenates of rat and monkey were measured at various levels of pH, ranging from 6.6 to 7.6. Technetium-99m-L,L-ethyl cysteinate dimer metabolism was also examined in the presence of purified enzymes. RESULTS: In both species, the metabolic rate was high in liver tissue, intermediate in brain tissue and low in blood. The rate in cerebral gray matter of cynomolgus monkey was higher than those in rat brain, monkey cerebral white matter and monkey cerebellar gray matter. All substances used as inhibitors depressed 99mTc-ECD metabolism, and the response was different among tissues. Reduction in pH induced slight decreases in metabolic rate. Hydrophilic conversion of 99mTc-ECD was observed after incubation with porcine liver carboxylesterase. CONCLUSION: These results support the hypothesis that the hydrophilic conversion of 99mTc-ECD is mediated by enzymes. It is also suggested that various enzymes catalyze the hydrolysis of 99mTc-ECD and that the enzymatic system that metabolizes 99mTc-ECD is different between tissues and between species.

Acetylcholinesterase↗
PubMed1997

Neural network-based PET image reconstruction.

In PET image analysis, conventional deconvolution alone will not give sufficient information for a precise study of a localized brain function. In the deconvolution process, which is a type of inverse problem, it is important to confine the solution space by incorporating a priori knowledge such as the tissue distribution given by MR images as well as smoothness in the blood flow distribution profile. An MR-embedded neural-network model is described to reduce the partial volume effect in the restoration of blood flow profiles from PET images.

Brain↗
PubMed1996

Laser Spectroscopy of the CCO Radical in the 0.77-μm Region: Analysis of the A(020)kappa3Pi and A3Pii(001) States

The A(020)kappa3Pi-X3Sigma-(000) and A3Pii(001)-X3Sigma-(000) bands of the CCO radical have been investigated by laser spectroscopy with two types of tunable laser system. An analysis was made simultaneously for both the bands to establish line assignments and determine molecular constants for both the A(020) and A(001) states. A coupling constant between these two states was also determined by assuming the interaction to be of Fermi type.

Journal Article↗
PubMed1996

Simple method to quantify myocardial glucose metabolism from MB ratio in myocardial FDG PET.

To provide a simple means of quantifying myocardial glucose metabolism, we tried to estimate the K complex (KC) from the myocardium to background ratio (MB ratio), which was obtained with a single static FDG scan and single venous sampling. In 48 fasting subjects and 74 subjects under oral glucose loading or insulin clamp, the reference KC was obtained from Patlak analysis by using an input function. We compared the reference KC with the MB ratio at 35 min 45 sec, 45 min 45 sec, and 55 min 45 sec, and with the FDG uptake index (FUI) reported by Tamaki. The correlation between KC and each index was very close during fasting (r = 0.97, 0.98, 0.98 and 0.97, respectively n = 48), and clinically acceptable during oral glucose loading and insulin clamp (r = 0.92, 0.91, 0.90 and 0.93, respectively n = 74). The average differences between the reference KC and KC estimated from the simple method were 13%, 10%, 8%, and 13%, respectively, during fasting, and 15%, 14%, and 16%, respectively, during oral glucose loading and insulin clamp. Both the MB ratio and FDG uptake index can be used for the simple estimation of myocardial glucose metabolism not only during fasting but also during oral glucose loading and insulin clamp, although the MB ratios at 45 min and at 55 min were slightly better than MB that at 35 min and the FDG uptake index during fasting.

Adult↗
PubMed1996

PET analysis of a case of cerebrotendinous xanthomatosis presenting hemiparkinsonism.

We describe a 34-year-old Japanese woman presenting gait difficulty and Achilles tendon swelling. The patient was diagnosed as having cerebrotendinous xanthomatosis (CTX) based on the high serum cholestanol level and diminished enzymatic activity of 27-hydroxylase of fibroblasts from her skin. Her clinical presentation was atypical regarding the presence of hemiparkinsonism and absence of apparent cataract, dementia, and cerebellar ataxia. Although MRI studies could not detect any abnormality in the basal ganglia or midbrain, PET analysis using [18F]-6-fluoro-L-dopa revealed reduced uptake of dopamine into the putamen, suggesting the impairment of presynaptic dopaminergic neurons.

Adult↗
PubMed1996

A multicenter validation of regional cerebral blood flow quantitation using [123I]iodoamphetamine and single photon emission computed tomography.

Recently, two methods have been proposed for regional cerebral blood flow (rCBF) quantitation using [123I]iodoamphetamine (IMP) and single-photon emission computed tomography (SPECT). The table look-up (TLU) method has been shown to provide both rCBF and volume of distribution, Vd, images from two SPECT scans, while a single-scan autoradiographic (ARG) technique provided rCBF using a fixed and assumed Vd. In both methods, a single blood sample was referred to calibrate the previously determined standard input function. The present multicenter project was designed to evaluate the accuracy of both methods for use as clinical investigative tools. Ten independent institutions performed [123I]IMP-SPECT studies according to both methods in 76 subjects (10 normal volunteers, 32 patients with cerebrovascular disease, and 34 patients with other diseases). Calculated rCBF values were compared with those obtained by the following reference methods available in the participating institutions; [15O] H2O positron emission tomography (PET) (five institutions), [133Xe]SPECT (four institutions), and the [123I]IMP microsphere method (three institutions). Both ARG and TLU methods provided rCBF values that were significantly correlated with those measured by the [15O] H2O PET technique (p < 0.001 for all subjects; overall regression equation, y = 15.14 + 0.54x) and those measured by the [123I]IMP-microsphere method (p < 0.001 for all subjects: y = 2.0 + 0.80x). Significant correlation (p < 0.05) was observed in 18 of 24 subjects studied with the [133Xe] SPECT reference technique (overall regression equation, y = 15.0 + 0.55x). Mean cortical gray matter rCBF in a group of normal subject was 43.9 +/- 3.3 and 43.4 +/- 2.0 ml/min/100 g for the ARG and TLU methods, respectively. Regional Vd of [123I]IMP estimated by the TLU method was 45 ml/ml +/- 20% in the normal cortical region. Close agreement between ARG and TLU rCBF values was observed (y = -3.21 + 1.07x, r = 0.97), confirming the validity of assuming a fixed Vd in the ARG method. Results of this study demonstrate that both the ARG and TLU methods accurately and reliably estimate rCBF in a variety of clinical settings.

Adolescent↗
PubMed1996

Avoidant personality disorder and taijin kyoufu: sociocultural implications of the WHO/ADAMHA International Study of Personality Disorders in Japan.

This paper discusses the characteristics of avoidant personality disorder in a cultural context based on the Japanese concept of taijin kyoufu as well as that of DSM-III-R and DSM-IV social phobia. Sixty-six patients were given the International Personality Disorder Examination and questionnaires including the Beck Anxiety Inventory. Among the 23 DSM-III-R personality disorder patients, 8 patients were diagnosed as having avoidant personality disorder. Six of them were suffering from taijin kyoufu symptoms. Among 27 ICD personality disorder patients, 22 patients were diagnosed as having ICD anxious personality disorder. All DSM avoidant patients were included in the ICD anxious group. These findings suggest that patients with avoidant personality disorder have had a long history of difficulties and share common personality problems with a milder form of taijin kyoufu, which is conceptually different from social phobia.

Adolescent↗
PubMed1996

A clinical profile of corticobasal degeneration presenting as primary progressive aphasia.

We report a patient with primary progressive aphasia who first presented with amnesic aphasia that developed over the course of 3 years into nonfluent aphasia with buccofacial apraxia, followed in the next year by cognitive impairment and parkinsonism. Pathological findings were typical for corticobasal degeneration except for the distribution of cortical atrophy. This case suggests that corticobasal degeneration should be included in the differential diagnosis of primary progressive aphasia, especially in association with parkinsonism.

Aphasia, Primary Progressive↗
PubMed1996

Activation of prefrontal and posterior superior temporal areas in visual calculation.

Regional cerebral blood flow was measured with H2(15)O-positron emission tomography during the performance of visually presented calculation tasks to clarify cortical areas involved in arithmetic operations. The findings on a calculation task were compared with those on a covert reading task and with those of a fixation control task. Region of interest-based analysis showed that the left prefrontal area was activated in visual calculation relative to covert reading and the posterior superior temporal gyrus including part of Wernicke's area was activated in calculation relative to fixation control. The role of the prefrontal area in computation (arithmetic operations) and that of the posterior superior temporal gyrus in both comprehension of the stimuli and computation were suggested.

Adolescent↗
PubMed1996

[The mechanism of controlling regional cerebral blood flow in patients with localization-related epilepsy].

INTRODUCTION: Hypoperfusion around the seizure foci has been reported in interictal CBF studies of partial epilepsy. Hypoperfusion may reflect some interictal pathophysiology characteristic of epilepsy, but the mechanism remains to be elucidated. In order to elucidate the controlling system of rCBF in patients with CPS (complex partial seizure), we measured by positron emission tomography rCBF and CO2 vasoreactivity performing a hyperventilatory task, and made comparisons between the affected and contralateral sides of the temporal lobes in CPS patients and the temporal lobe of normal volunteers. We also measured PaCO2, pH, PaO2 and respiratory rate at rest to elucidate the CBF maintaining system. SUBJECTS: 15 volunteers and 12 medically controlled patients with CPS were examined. The affected side of the brain of the patients was determined by dominance of EEG paroxysm. METHOD: For measuring rCBF, the Shimadzu HEADTOME-IV system (8mm FWHM) and H2(15)O (740-1480 [MBq]/scan) bolus injection method were employed. First a rest scan, then a hyperventilatory task scan was performed, at 20 min. intervals between each scan. During the rest scans, the subjects were required to close their eyes, which were covered through the transmission scan and all the other scans. They were monitered with EEG to insure that they were not asleep. Room lights were dimmed, room sounds were kept to a minimum and noises were damped with earplugs. During the hyperventilatory tasks, the subjects were asked to inspire deeply at a rate of 15/min. for 4.5 min. from 3 min. before the scan up to the end of the 1.5 min. scan, and monitored with a respiratory band around the abdomen. Arterial blood gas pressures (PaCO2, pH and PaO2) were also measured with a blood gas analyzer (Radio Meter ABL 330) at the beginning and at the end of the scans. [HCO3-] was calculated on the formula of Henderson-Hasselbalch. Vascular response to PaCO2 change: VrCO2 was defined as follows: VrCO2 = 100 x (CBFh-CBFr)/CBFr/(PaCO2h-PaCO2r) the subscripts h: hyperventilatory r: resting conditions. RESULTS: Blood gasses, rCBF and corrected-rCBF at rest: In the patients, PaCO2 (mmHg) = 46.11 +/- 2.32, pH = 7.374 +/- 0.020, [HCO3-] (mEq/ml) = 25.98 +/- 1.15, CBF (ml/100g/min) = 45.51 +/- 9.33, corrected-CBF (ml/100g/min) = 40.06 +/- 7.27. In the volunteers, PaCO2 = 40. 67 +/- 2.37, pH = 7.400 +/- 0.021, [HCO3-] = 24.36 +/- 1.66, CBF = 48.76 +/- 8.54, corrected-CBF = 48.02 +/- 9.04. PaCO2 and [HCO3-] in the patients were significantly higher than those in the volunteers. pH and corrected-CBF were significantly lower than those in the volunteers. CBF showed no difference. VrCO2 in the temporal lobe: In the affected side of the patients, VrCO2 = 1.976 +/- 0.54. In the contralateral side of the patients, VrCO2 = 2.145 +/- 0.667. In the temporal lobe of the volunteers, VrCO2 = 2.557 +/- 0.898. In both sides of the temporal lobe of the patients, VrCO2 was significantly lower than those in the volunteers. COMMENTS: The effect of anticonvulsant drugs and the suppressive mechanism around the foci are supposed to reduce CBF of CPS patients. We suppose another mechanism, which is vasoconstriction. A significant difference was noted in CO2-vasoreactivity in the temporal lobe between patients and volunteers. Also no difference was noted in rCBF in the temporal lobe between the volunteers and the patients, when the arteries were maximally constricted with the HIV-task. These two results suggest that vasoconstrictive mechanism may be among the factors for the hypoperfusion seen in the temporal lobe of the patients. In patients, PaCO2, [H+], [HCO3-] were significantly higher compared with the volunteers, which suggests the mechanism of respiratory acidosis. Owing to this hypercapnia, global CBF in the patients is maintained in compensation for the hyperfusion and vasoconstriction seen around the foci. CO2 acts as an anticonvulsant and also reduces glucose metabolites which accumulate around the foci.

Adult↗
PubMed1995

Positron emission tomography of reversible intellectual impairment induced by long-term anticholinergic therapy.

Long-term oral anticholinergic (AC) therapy can occasionally produce intellectual impairment. We investigated a patient with Parkinson's disease accompanied by intellectual impairment induced by long-term AC therapy. The intellectual impairment of the patient disappeared after cessation of AC therapy. Positron emission tomography (PET), during and after long-term oral AC therapy, revealed that it causes bilateral diffuse decrease of glucose metabolism in the cortex, basal ganglia, thalamus, hippocampus and cerebellum. Cessation of the therapy resulted in diffuse increase of glucose metabolism in all of the above regions. Cranial CT and magnetic resonance imaging (MRI) showed no abnormalities. Our results suggest that long-term AC therapy causes reversible bilateral diffuse glucose hypometabolism.

Aged↗
PubMed1995

Spinal muscular atrophy with oculomotor palsy, epilepsy, and cerebellar hypoperfusion.

We report a boy with spinal muscular atrophy (SMA) type 1, who developed novel clinical and neuroradiologic features, indicating the broad spectrum of this degenerative disease. Widespread lesions in the central nervous system were disclosed by magnetic resonance imaging and single photon emission computed tomography (SPECT) studies. In particular, scattered regions of hypoperfusion demonstrated by SPECT suggested multisystem involvement including the cerebellum. The novel features of this patient were complex partial seizures and oculomotor palsy.

Cerebellum↗
PubMed1995

An approach to cerebral vasodilatory capacity in unilateral and bilateral cerebrovascular diseases using radiolabeled human serum albumin.

The acute cerebrovascular response to acetazolamide was assessed using a blood pool agent and planar dynamic imaging to evaluate cerebral vasodilatory capacity. Ten normal subjects and 12 patients with unilateral or bilateral cerebrovascular disease were studied. After the injection of radiolabeled human serum albumin, dynamic imaging of the anterior view of the head was started. Ten minutes later, 1000 mg of acetazolamide was infused. The dilatation index (the percent increase in activity at the peak response) was obtained for each cerebral hemisphere. The mean dilatation index in normal subjects was 17.1 +/- 3.2% (N = 20). The value was significantly lower in patients with multiple infarcts (7.7 +/- 1.1%, N = 8, P < 0.001), and below the normal range in two involved hemispheres of five patients with unilateral occlusive carotid artery disease and in three hemispheres of three patients with moyamoya disease. It was suggested that this simple method may be useful in assessing cerebral vasodilatory capacity in both unilateral and bilateral diseases.

Acetazolamide↗
PubMed1995

[A hemodialysis patient with HTLV-1-associated myelopathy (HAM)].

We report here a case of maintenance hemodialysis with HTLV-1 associated myelopathy (HAM). A 53-year-old female hemodialysis patient was admitted to Teikyo University Ichihara hospital because of paralytic ileus. She had a history of blood transfusion and had been under dialysis treatment for 8 years. She had experienced gait disturbance and sensory disturbance in her lower extremities for 8 years. Neurological examination revealed myelopathy and neuropathy. Laboratory data revealed that serum anti-HTLV-1-antibody was over 1260 x (PA) and liquor HTLV-1-antibody was over 160 x (PA). Her liquor revealed a cell count of 4/3 cmm, protein 22 mg/dl, glucose 45 mg/dl, chloride 125 mEq/l and no atypical cells. To the best of our knowledge this is a rare case in Japan. Our findings suggest that HAM should be taken into consideration when we diagnose a maintenance hemodialysis patient showing neuropathy and myelopathy.

Female↗
PubMed1995

[A case of chronic eosinophilic pneumonia involving IL-5 and GM-CSF].

A 57-year-old woman was admitted because of dry cough and middle-grade fever. Chest rentogenogram showed a diffuse infiltrative shadow in the right middle and lower lung fields. The symptoms disappeared after treatment with minocycline, but a new dense shadow appeared in the right upper and middle lung fields. Eosinophilic pneumonia was diagnosed from the results of bronchoalveolar lavage and transbronchial lung biopsy. The symptoms were alleviated and the infiltrative shadow was effaced after treatment with predonisolone (40 mg/day). The results of a biopsy with human eosinophils suggested that the serum and bronchoalveolar lavage fluid contained IL-5 and GM-CSF.

Bronchoalveolar Lavage Fluid↗
PubMed1995

[An adult case of hemolytic uremic syndrome (HUS) after pathogenic Escherichia coli (E. coli) infection].

In recent years, it has been revealed that verocytotoxin-producing E. coli (VTEC) infection is one of the leading causes of HUS and the molecular aspects of its pathophysiology have also been studied extensively. We report a case of a 56-year-old man who developed HUS after E. coli (O 26 strain) infection with diarrhea. The characteristic laboratory findings in this case included hypergammaglobulinemia, hypocomplementemia and a high level of immune complex in addition to the common findings of HUS. The light microscopic findings of the first renal biopsy performed before treatment revealed extensive interstitial changes with remarkable mononuclear cell infiltrations as well as mild mesangial proliferation with crescent formation. Subendothelial electron-dense deposits within the glomerular capillary walls and mesangial area were also detected by electron microscopic examination. The diagnostic possibilities of infectious endocarditis and collagen diseases, such as Sjögren syndrome, were reasonably ruled out by the appropriate examinations. After 2-month prednisolone therapy, proteinuria and deteriorated renal functions as well as the abnormal immunological parameters described above were remarkably improved. The second renal biopsy after treatments showed clearly diminished subendothelial deposits and interstitial mononuclear cell infiltrations. This case report might provide information on the unique features of renal interstitial damage and immunological abnormalities in VTEC-induced adult HUS.

Bacterial Toxins↗