Biomedical subjects

Yasushi Oya

Publications and source records attributed to Yasushi Oya.

15 recordsLinked to original sources

PubMed2005

[Perception of dyspnea due to breath-holding in myotonic dystrophy].

Patients with myotonic dystrophy (DM1) rarely complain of dyspnea despite of severe hypoxemia. We studied the perception of dyspnea caused by breath-holding in 9 DM1 patients and 8 healthy control subjects. The patients, as well as the control subjects, complained of dyspnea and showed decrease in SpO2. In none of the patients but one, however, the bottom SpO2 became lower than the minimal SpO2 recorded in 24-hour monitoring. DM1 patients were able to realize hypoxia caused by apnea, although they had not realized hypoxia that already existed. Consequently, the breath-holding test does not uncover a blunted perception of dyspnea in DM1; an afferent system contributable to air hunger sensation in breath-holding is preserved in DM1. Breath-holding test may be useful for a DM1 patient to recognize the significance of sleep apnea.

Adult↗

PubMed2005

[Long-term treatment of diabetes mellitus in myotonic dystrophy with pioglitazone].

We report beneficial effects of pioglitazone on insulin resistance in diabetes mellitus accompanied with myotonic dystrophy (DM1). We studied eight DM1 patients with diabetes mellitus aged 32 to 60 (mean age 52.1 +/- 8.6 years). Three of them were under glibenclamide treatment, but their plasma glucose control was poor because of occasional hypoglycemia; others had not been treated with any hypoglycemic drugs. We administered a daily dose of 15 mg pioglitazone for 6-36 months (mean period 14.8 +/- 9.1 months). Plasma glucose control improved in all patients. In a 75 g oral glucose tolerance test, plasma glucose level at 120 min dropped from 203.3 +/- 41.7 mg/dl to 153.9 +/- 39.5 mg/dl (p = 0.04); the area under the insulin curve up to 120 min (sigma IRI) dropped from 236.9 +/- 170.2 microU x hr/ml to 169.6 +/- 81.3 microU x hr/ml (p = 0.12). Sigma IRI decreased in four patients with pretreatment sigma IRI > or = 250 microU x hr/ml; it slightly increased in other patients with pretreatment sigma IRI < or = 150 microU x hr/ml. The homeostasis model assessment-insulin resistance (HOMA-IR) improved from 2.1 +/- 1.0 to 1.1 +/- 0.4 (p = 0.04). Impairment of liver functions, cardiac failure, or hypoglycemia was not observed. Pioglitazone treatment is useful to improve insulin resistance and glucose control in DM1 patients with diabetes mellitus, especially patients with reactive hyperinsulinemia to glucose loading.

Adult↗

PubMed2004

Whole-brain voxel-based correlation analysis between regional cerebral blood flow and intelligence quotient score in Parkinson's disease.

The correlation between regional cerebral blood flow (rCBF) and intelligence quotient (IQ) score was investigated in patients with Parkinson's disease (PD) without severe dementia. We analyzed the (9mTc-ethyl cysteinate dimer single-photon emission computed tomography quantitative images and Revised Wechsler Adult Intelligence Scale scores of 44 PD patients using statistical parametric mapping. Verbal IQ positively correlated with rCBF in the right ventral striatum and the bilateral prefrontal cortex, performance IQ positively correlated with rCBF in the right operculum, insula and the left middle temporal gyrus, and full-scale IQ positively correlated with rCBF in the right operculum, insula and the ventral striatum. The identified areas may be functionally related to mild to moderate cognitive impairment in patients with PD.

Aged↗

PubMed2004

FSHD-like patients without 4q35 deletion.

Facioscapulohumeral muscular dystrophy (FSHD) is characterized by progressive weakness and wasting of facial, shoulder-girdle and upper arm muscles. Despite of the characteristic clinical features, the diagnosis of FSHD is sometimes difficult because clinical symptoms are extremely variable including facial sparing type, limb-girdle type, and distal myopathy type. Most of the FSHD patients have a deletion in the subtelomeric region of chromosome 4q35 (FSHMD1A), however the linkage analysis in some families suggested genetic heterogeneity. In the present study, we identified 40 patients without a deletion in the 4q35 region (non-4q35del) among 200 Japanese patients who were clinically suspected to have FHSD. All non-4q35del patients had shoulder-girdle weakness and 75% also had facial weakness. Eight patients showed clinical features that were indistinguishable from FSHD, but two of them had Becker muscular dystrophy. FSHD is clinically, and most likely genetically, as well, variable. Other forms of muscular dystrophy can also mimic FSHD.

Adolescent↗

PubMed2004

Reduction of UDP-N-acetylglucosamine 2-epimerase/N-acetylmannosamine kinase activity and sialylation in distal myopathy with rimmed vacuoles.

Distal myopathy with rimmed vacuoles is an autosomal recessive muscle disease with preferential involvement of the tibialis anterior that spares the quadriceps muscles in young adulthood. In a Japanese patient with distal myopathy with rimmed vacuoles, we identified pathogenic mutations in the gene encoding the bifunctional enzyme UDP-GlcNAc 2-epimerase/ManNAc kinase, which catalyzes the initial two steps in the biosynthesis of sialic acid. In this study, we demonstrated the relationship between the genetic mutations and enzymatic activities using an in vitro expression assay system. Furthermore, we also showed that the levels of sialic acid in muscle and primary cultured cells from DMRV patients were reduced to 60-75% of control. The reactivities to lectins were also variable in some myofibers, suggesting that hyposialylation and abnormal glycosylation in muscles may contribute to the focal accumulations of autophagic vacuoles, amyloid deposits, or both in patient muscle tissue. The addition of ManNAc and NeuAc to primary cultured cells normalized sialylation levels, thus demonstrating the therapeutic potential of these compounds for this disease.

Animals↗

PubMed2004

[Maximum phonation time as a tool of screening respiratory muscle weakness in myopathic patients].

UNLABELLED: We examined the relation of maximum phonation time (MPT) and vital capacity (VC) and reviewed the usefulness of MPT as a respiratory function screening. SUBJECTS: 18 healthy adult subjects (8 men and 10 women), and 32 myopathic patients (24 men and 8 women). METHODS: MPT and VC were measured in sitting position. Six patients were tested with and without air stacking by glossopharyngeal respiration. RESULTS: In healthy subjects, MPT was 29.9 +/- 11.8 seconds in men and 21.7 +/- 7.8 seconds in women. Second trials showed good reproducibility. The healthy group had no correlation between MPT and VC. The patient group showed a significant positive correlation between MPT and VC (r2= 0.25, p=0.003). All patients with MPT less than 15 seconds showed VC less than 1.5 l and %VC less than 50%. Air-stacking by glossopharyngeal respiration significantly increased the MPT. CONCLUSIONS: MPT is a useful screening test for respiratory muscle weakness. The patients are easily aware of the effect of air-stacking by glossopharyngeal respiration.

Adult↗

PubMed2003

D-cycloserine for the treatment of ataxia in spinocerebellar degeneration.

We studied the effects of D-cycloserine, a partial NMDA receptor allosteric agonist, on ataxia in patients with spinocerebellar degeneration. Fifteen Japanese ataxic patients enrolled in a 14-day single-blind trial of D-cycloserine (daily oral dose of 50 mg) following a 14-day single-blind placebo phase. At the end of the D-cycloserine administration, there was a significant reduction in the posture, gait and total score of the international cooperative ataxia rating scale and in the time for walking and speech tasks. D-Cycloserine was well-tolerated and no adverse effect was observed. D-Cycloserine may have therapeutic efficacy for spinocerebellar ataxia.

Adult↗

PubMed2003

[Dichloroacetate treatment for adult patients with mitochondrial disease].

We report beneficial and adverse effects of sodium dichloroacetate (DCA) in three adult Japanese patients with mitochondrial disease: a 21-year-old male with involuntary movements, optic atrophy, hearing loss, and convulsions (patient 1), a 28-year-old man with mental deterioration, hemianopia, hearing disturbance, and convulsions (patient 2), and a 50-year-old woman with hearing disturbance, generalized muscle atrophy, and insulin dependent diabetes mellitus (patient 3). A3243G mutation was found in patient 2 and patient 3. Oral administration of DCA improved consciousness level and gait disturbances in patient 1, and ameliorated headaches, easy fatiguability, and muscle cramps in patient 2 and patient 3. DCA normalized high levels of lactate and pyruvate in blood and cerebrospinal fluids in all three patients. In patient 3, daily insulin needs decreased from 38 to 24 units, and urine C peptide increased from an undetectable level to 16 micrograms/day. In patient 1, DCA 23 mg/kg/day had been beneficial without adverse effects and he became free of convulsions for more than 32 months. However, despite of normal lactate and pyruvate, unsteady gait and lethargy developed after 50 mg/kg/day treatment for two months and one month in patient 2 and patient 3, respectively. In both patients, deep tendon reflexes disappeared and Romberg sign became positive. Nerve conduction studies confirmed sensory-dominant polyneuropathy and electroencephalogram showed diffuse slow basic activities. Cessation of DCA resulted in recovery of gait and consciousness, but sensory nerve action potentials did not recover in one month. Long term treatment of 50 mg/kg/day DCA may affect adversely the peripheral and central nervous systems in adult patients. Although effective plasma DCA concentration was previously reported as 25-160 micrograms/ml in patients under 18 years old, plasma DCA concentration of 10.2 micrograms/ml was sufficient in patient 1. We recommend lower dose of DCA in adult patients than in child patients.

Adult↗

PubMed2003

[A follow-up study on brainstem atrophy in progressive supranuclear palsy--when does brain MRI contribute to the differential diagnosis between progressive supranuclear palsy and Parkinson disease?].

OBJECTIVE: To investigate when the MRI can discriminate progressive supranuclear palsy (PSP) from Parkinson disease (PD). METHODS: We obtained the following parameters using T1-weighted axial images of the midbrain and the middle pons from 40 studies of 17 PSP patients and 26 studies of 26 PD patients; 1. anteroposterior diameter of the pons (Pons AP), 2. anteroposterior length of the pontine tegmentum (Pons T), 3. anteroposterior diameter of the midbrain (Midbrain AP), 4. ratio of anteroposterior diameter of the pontine base to that of the pontine tegmentum (Pons B/T ratio), 5. ratio of the sum of the bilateral crus cerebri widths to the midbrain AP (Midbrain [Cr + Cl]/AP ratio). All the PSP patients were studied more than twice and each study was classified into four groups according to the duration of the illness; (1) less than 24 months (7 studies), (2) from 24 to 47 months (10 studies), (3) from 48 to 71 months (14 studies) and (4) 72 months or longer (9 studies). RESULT: The first MRI studies (duration of disease 39.9 +/- 22.1 months) were compared with the second studies (duration of disease 67.6 +/- 31.6 months) in 17 PSP patients. Pons AP, Pons T, and Midbrain AP were significantly smaller in the second studies, indicating progressive pontine and midbrain atrophy. Compared with the PD group, the PSP group showed significant atrophy four years after onset of the disease in Pons AP and two years in Pons T. Pons B/T ratio, and Midbrain [Cr + Cl]/AP ratio were significantly smaller in the PSP group two years after onset, suggesting midbrain and pontine tegmentum atrophy. The diagnostic MRI criteria of Pons B/T ratio more than four and Midbrain [Cr + Cl]/AP ratio more than two each showed accuracy in PSP of more than 70% two years after onset. CONCLUSIONS: Discrimination of PSP from PD was difficult during the first two years after onset. The atrophic process in the midbrain and the pontine tegmentum may precede that of the pontine base. Pons B/T ratio and Midbrain [Cr + Cl]/AP ratio presented here are potentially good indexes for the discrimination of these two diseases.

Aged↗

PubMed2002

[Juvenile-onset multiple brain infarcts localized in the posterior circulation: a case report].

We report a 37-year-old male patient with multiple brain infarcts due to arterial lesions localized in the posterior circulation, who developed a paramedian pontine infarct on the left side. He had been treated as schizophrenia for 20 years. A cranial CT performed one year before showed old small infarcts in the territories of the bilateral thalamo-perforating and left thalamo-geniculate arteries and the right posterior inferior cerebellar artery. The vertebral and basilar arteries were small in diameter on MRI and MR angiography(MRA). Cerebral angiography revealed a narrow smooth basilar artery. In addition, the P2 segments of the bilateral posterior cerebral arteries were markedly narrow with irregular walls. Carotid arteriograms were normal and no atherosclerosis was found. The nature of these arterial lesions remains unknown in this case. Even if MRA shows vertebrobasilar artery hypoplasia, a known congenital risk factor of a posterior circulation infarct, we must rule out a possibility that some arterial pathology is going on.

Adult↗

PubMed2002

[A case of relapsing myelitis associated with hypocomplementemia, presenting with Lhermitte sign enhanced by truncal flexion].

A 36-year-old woman suffered from steroid-responsive relapsing myelitis associated with hypocomplementemia, thrombocytopenia, and anti-cardiolipin antibody. At the second attack of paraplegia, neck flexion in a supine position induced uncomfortable dysesthesia radiating into the ulnar side of the bilateral forearms. Both truncal and neck flexion resulted in painful dysesthesia down into both lower limbs also. Cervical MRI showed 2 gadolinium-enhanced dorsal-dominant lesions in the spinal cord at C 5/6 and C 6/7 disc levels. Enhancement of Lhermitte sign by truncal flexion might be useful to detect multiple lesions in the dorsal column.

Adult↗

PubMed2002

[Facioscapulohumeral muscular dystrophy with sinus dysfunction].

We report a 47-year-old man with facioscapulohumeral muscular dystrophy (FSHD) presenting with sinus dysfunction. He became unable to roll over and stand up at the age of 42, but he could still walk. Facial muscle involvement, scapular winging, asymmetrical involvement, funnel chest, and the absence of contractures were typical of FSHD. Electrocardiogram (ECG) and cardiac echogram showed the overload of both right atrium and ventricle. On Holter ECG, transient P wave inversion and P-P interval elongation (maximally 2.4 seconds) repeatedly appeared mainly during sleep. There was no bundle branch block, atrioventricular junctional rhythm, or increase of premature ventricular beats. Vital capacity was decreased (0.62 L, 16% of the predicted value). Arterial blood gas analysis showed hypercapnia and hypoxia which aggravated during sleep (PaCO2 87.3Torr, PaO2 41.5Torr). Sleep apnea was not observed. Intracardiac ECG was not performed and he died 2 weeks later. In FSHD, sinus node dysfunction may become distinct especially in the setting of respiratory failure.

Electrocardiography, Ambulatory↗

PubMed2002

[Compulsive repetition of movements in a case of progressive supranuclear palsy].

A 51-year-old right-handed man with an 8-year history of progressive supranuclear palsy developed a peculiar behavior including compulsive repetition of movements. At the age of 47, it was noted that he continuously scratched his trunk with the right hand. He also scratched his thighs until his trousers were torn. On the scalp, posterior neck and forearms, patches of skin were scraped away and the bleeding wounds were scratched over and over again. Although he perceived pain, he could not terminate the strange scratching movement. He could not stop his eating action even after the bowl became empty. He could not leave the bathroom because he continued to wipe the anus after defecation. Yet the patient was not demented. Psychometric assessments including Wechsler adult intelligence scale revised, meaningful and meaningless syllables memory test. Raven's color matrix test, Wisconsin card sorting test (Keio version), and modified Stroop test were within the normal range. When requested to write a letter or a figure, he was always successful, however, he endlessly wrote the same letter or figure until he was told to stop. Although he repeated the behavior and could not terminate the action by himself, he immediately stopped the action on verbal command. When another task was given during the repetitive action, he responded quickly and successfully. His strange behavior was compulsive because he wanted to cease it, but it was not compulsive-obsessive behavior because he did not feel anxiety or pain when his repetitive action was stopped. It was different from stereotypy because he repeated not only meaningless movements but also meaningful complex actions. Unlike perseveration, he changed his activity immediately and successfully when a new task was given. Magnetic resonance imaging findings were remarkable only for mild atrophy of the midbrain tegmentum. Single photon emission computed tomography with ethyl cysteinate dimer demonstrated hypoperfusion in the frontal lobes and the left thalamus. A thalamofrontal disconnection or dysfunction is suggested as the mechanism underlying the compulsive repetifim of moving its based on the SPECT findings in this patient.

Compulsive Behavior↗

PubMedDate not supplied

[Respiratory system elastance and resistance measured by proportional assist ventilation in patients with respiratory muscle weakness].

OBJECTIVE: Non-invasive ventilatory therapy has prolonged survival of myopathy patients with hypoventilation. Efficacy of non-invasive ventilation depends on both elastance and resistance of the respiratory system. Although these parameters are important in the prescription of respiratory management, conventional respiratory function test does not show the appropriate answer in patients with severe respiratory muscle weakness. In muscular dystrophy, muscle tends to be shortened due to its fibrosis, when muscle becomes atrophic and weak; fibrosis of respiratory muscle tissues presumably causes high thoracic elastance. We evaluated the total respiratory system elastance and resistance during proportional assist ventilation (PAV) in myopathy patients. METHODS: In PAV with 100% assist, using BiPAP Vision ventilator, airway pressure exceeds 20 cmH2O or tidal volume exceeds 1.5 liter (run-away phenomenon) when the volume assist or the flow assist is higher than the individual elastance or the resistance, respectively. Twenty myopathy patients with ventilatory failure and 7 healthy controls were evaluated, including 7 patients with Duchenne muscular dystrophy (DMD), 2 patients with congenital myopathy (CM), 1 patient with limb-girdle muscular dystrophy (LG), 6 patients with myotonic dystrophy (MyD) and 4 patients with acid maltase deficiency (AMD). Seventeen patients used a nasal mask and 3 patients had a tracheostomy tube. Fifteen patients used a pressure-preset ventilator, and 3 patients used a volume-preset ventilator. RESULTS: In all patients with DMD, CM and LG, respiratory system elastance was higher than 20 (cmH2O/L) and than in all patients with AMD and MyD except 1 MyD patient. Follow-up measurement after half a or one year showed increase of respiratory system elastance in 2 DMD patients and 1 CM patient, but almost no change in 3 AMD patients. The elastance measured during PAV was consistent with the clinical impression of muscle shortening. One exceptional MyD patient showed extremely high elastance (more than 58 cmH2O/L), which reflected the fixed thoracic spine and increase of abdominal visceral fat. Resistance was normal in all patients except a LG patient with pulmonary aspergillosis and a history of pulmonary tuberculosis who showed 14 (cmH2O/L/s). In a CM patient who developed emphysema, resistance increased from 5 to 12 (cmH2O/L/s) in a year, although forced expiratory volume 1.0% (FEV1.0/FVC) remained normal. Respiratory system resistance measurement was useful to detect a lung disease, because obstructive disorder is underestimated with FEV1.0/FVC when vital capacity is low. CONCLUSION: The respiratory system elastance and resistance measured during PAV are useful parameters in evaluation of mechanical features of the lung, thorax and airway. It is recommended to keep both parameters normal in patients who may require ventilatory assist due to progression of respiratory muscle weakness.

Adult↗

PubMedDate not supplied

[Palpable orbital subcutaneous masses in chronic inflammatory demyelinating polyneuropathy. MRI and neurophysiological study of multiple peripheral nerve swelling].

We report a 46-year-old woman with chronic inflammatory demyelinating polyneuropathy (CIDP) in whom swelling of the first branch of the trigeminal nerves in the bilateral orbits were observed as subcutaneous masses in the upper eyelids. The disease developed when the patient was 33 years old, and weakness of the four limbs, double vision, unilateral hypoglossal neuroparalysis, and unilateral facial paralysis frequently occurred during the course of the illness. On nerve conduction studies, conduction block was detected in the motor nerves. Steroid therapy and immunoglobulin treatment improved the symptoms. At 43 years old, subcutaneous phymas were noted in the bilateral upper eyelids, and fat-suppressed MRI detected the phymas localized along the upper region of the superior straight muscle in the bilateral orbits, and the muscles were slightly compressed downward. The masses branched in the orbits, and were diagnosed as nerve swelling of the supraorbital nerve, the first branch of the trigeminal nerve. Fat-suppressed MRI also identified nerve swelling of the extracranial maxillary and mandibular nerves. However, the patient had no subjective sensory disturbance in the trigeminal nerve region. Blink reflex did not induce R1 and R2 exhibited low amplitude and delayed latency. MRI confirmed asymmetric nerve swelling in the regions of the bilateral median nerves with motor nerve conduction block. Lumbar MRI detected nerve swelling in the peripheral nerves distant from the lumbar ganglion. MRI detected no nerve swelling in the arachnoid space such as the cervical cord, thoracic cord, or cauda equina. Aggravation of CIDP was treated with steroids and immunoglobulin. Diplopia occasionally appeared, but was not consistent with aggravation of CIDP. The bilateral supraorbital nerves remained unchanged for three years on MRI.

Chronic Disease↗