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Biomedical subjects

Z Shiozawa

Publications and source records attributed to Z Shiozawa.

At least 19 recordsLinked to original sources

Sleep apnoea in well-controlled myasthenia gravis and the effect of thymectomy.

We conducted overnight polysomnographic sleep studies of 16 patients (5 men and 11 women) with clinically well-controlled myasthenia gravis (MG). The subtypes of MG were IIA (3 patients), IIB (11 patients), IV (1 patient) and V (1 patient). Twelve patients were found on polysomnography to have obstructive and/or central types of the sleep apnoeas (SA). Their mean age was 42.4, SD 16.4 years, and the mean duration of MG was 7.4, SD 6.96 years. SA was not detected in 4 patients whose mean age was 30.8, SD 10.71 years and who had manifested MG for a mean duration of only 0.9, SD 0.65 years. Thus, patients with a longer duration of MG tended to have more SA. In 9 of the 12 SA patients, polysomnographic studies were repeated following thymectomy. SA had resolved in 6 patients, but persisted in 3. These findings suggest that SA is a possible clinical manifestiation of MG and that nocturnal dysfunction of both peripheral and central colinergic systems may be involved.

Adult

Decreased sympathetic outflow to muscles in patients with cervical spondylosis.

To clarify the pathogenesis of neurologic symptoms of a vascular nature that may accompany cervical spondylosis (CS), we measured the sympathetic outflow to muscles (muscle sympathetic nerve activity: MSNA) in 8 ambulatory patients with CS and 10 healthy volunteers (controls). The burst rate and incidence of MSNA at rest were significantly lower in patients with CS than in controls (P < 0.01). There were no differences between the 2 groups in either resting heart rate or blood pressure. During a head-up tilting, the changes in MSNA were slightly greater in CS patients than controls due to reduced baseline levels of MSNA in CS patients. The burst incidence of MSNA in CS was significantly negatively correlated with the severity of pyramidal tract symptoms (P < 0.05). The decreased MSNA at rest in CS patients may be due to a spinal cord compression resulting from posterior spondylotic changes in the cervical spine.

Aged

[Idiopathic hypertrophic cranial pachymeningitis associated with Horner's syndrome. A case report].

A 64-year-old man was admitted to our hospital for recurrence of visual disturbance and double vision experienced 1 year previously. He was alert and oriented. Bilateral light perception in a vision test, the third to the sixth cranial nerve palsies on the left side, and neck stiffness were observed. The patient exhibited left blepharoptosis, anisocoria and a left miotic pupil. After a pupillary drug test, a diagnosis of Horner's syndrome was made. Laboratory tests revealed hypoalbuminemia, elevated erythrocyte sedimentation rate, positive rheumatoid factor, and elevated p-ANCA. Examination of the cerebrospinal fluid showed increased initial pressure and pleocytosis, but its bacterial and fungal cultures were negative. Cranial magnetic resonance imaging after intravenous administration of gadolinium revealed mild brain edema and marked hypertrophy of the left tentorium cerebelli, bilateral frontal dura and falx. Marked hypertrophy of the dura accompanied by cellular infiltration was observed in biopsied dura specimens. The patient was given a diagnosis as idiopathic hypertrophic cranial pachymeningitis (IHCP). His ocular symptoms gradually improved with methylprednisolone pulse therapy and oral prednisolone. This is the first reported case of IHCP associated with Horner's syndrome. Previous anatomical findings of the cavernous sinus suggest that Horner syndrome in this patient might be due to a mechanism other than constrictive compression of the cranial nerves by the hypertrophic dura mater.

Anisocoria

Unilateral tongue atrophy due to an enlarged emissary vein in the hypoglossal canal.

A 16-year-old girl presented to our clinic with right-sided tongue atrophy and fasciculations of 1-year duration. Enlargement of the outer opening of the hypoglossal canal was reveal by conventional and computed tomography of the skull. Magnetic resonance imaging disclosed an enlarged venous system extending from the jugular vein to the internal jugular vein on the right, with low signal density suggestive of a flow void. A right-sided occipital craniotomy was performed. When the hypoglossal canal was opened, an enlarged emissary vein compressing the hypoglossal nerve was identified. This is the first reported case of unilateral tongue atrophy and an enlarged hypoglossal canal due to an enlarged emissary vein.

Adolescent

[Sleep disorders].

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Autonomic Nervous System

Increased sympathetic outflow to muscles in patients with amyotrophic lateral sclerosis: a comparison with other neuromuscular patients.

We investigated the effects of muscle loss and limitation of daily activities on sympathetic outflow to muscles by measuring muscle sympathetic nerve activity (MSNA) in 12 patients with amyotrophic lateral sclerosis (ALS) as compared with other 15 neuromuscular patients (controls). The burst incidence of MSNA at rest was significantly higher in patients with ALS, even in elderly patients, compared with controls (p < 0.01). There were no differences in the level of disability, heart rate or blood pressure at rest between two groups. Blood pressure and MSNA were less changed by head-up tilting in patients with ALS compared with controls. MSNA of ALS was not correlated with the disability score, PaO2, PaCO2, forced vital capacity, the disease duration or prognosis. MSNA at rest was increased in ALS patients, regardless of the severity of muscle loss or disability. It might be suggested that autonomic motor neurons seem to become affected by the same pathologic process that kills motor neurons.

Adult

Amyotrophic cervical myelopathy in adolescence.

The clinical and radiological features in seven patients who had asymmetric muscular atrophy of the hand and forearm when young are reported and a new hypothesis for its aetiology is proposed. Investigation of body growth curves (a surrogate for velocity of arm growth) showed close relation between (a) the age when the body height increased most rapidly and the onset age of this disorder, and (b) the age when the rapid body growth period ended and the age when symptom progression ceased. Cervical radiological evidence is provided showing asymmetric anterior cord atrophy, disappearance of slackness of dorsal roots in neck extension, and anterior and lateral displacement of the lower cervical cord against the posterior aspects of the vertebral bodies during neck flexion. These results suggest that disproportionate shortening of the dorsal roots is further accentuated during the juvenile growth spurt, which determines the onset and self limited course of the condition, and that repeated neck flexion causes micro-trauma and relative ischaemia of anterior horn cells, which finally results in atrophy of the muscles innervated by motoneurons with long axons. Predisposing anatomical factors are a straight neck due to lack of physiological cervical lordosis and the presence of foreshortened dorsal roots.

Adolescent

A single amino acid substitution within the mature sequence of ornithine aminotransferase obstructs mitochondrial entry of the precursor.

We describe here evidence of congenital enzyme mistargeting induced not by abnormalities in the signal sequence. We examined the molecular mechanism of hereditary ornithine aminotransferase (OAT) deficiency causing gyrate atrophy of the choroid and retina (GACR). Nucleotide sequencing of OAT cDNA generated from a GACR patient's mRNA revealed a single base change from C to G at position 268, resulting in an amino acid substitution of neutral Gln(CAA) with negatively charged Glu(GAA) at position 90 (Q90E). Immunohistochemical and transient expression analyses suggested expression of a defective labile OAT in the patient's tissues. However, high-level expression and immunocytochemical analyses elucidated that Q90E OAT (the patient's OAT) was localized within the limits of cytoplasmic free ribosomes in precursor form without any mitochondrial entry, indicating that the patient's precursor OAT was synthesized and rapidly degraded because of accumulation in the cytosol. It is interesting that, although the mutation site (Q90E) in this GACR patient's OAT was within the coding sequence of the mature protein, the precursor exhibited loss of mitochondrial targeting function. These findings suggest that not only the signal sequence but a critical part of the mature sequence plays an essential role in mitochondrial entry of the OAT precursor protein.

Adult

[A case of chronic progressive radiation myelopathy with cavity formation in the thoracic spinal cord].

A 70-year-old man was admitted to our hospital in March 1994 because of subacute progressive paraparesis and sensory impairment below the level of the second thoracic (TH 2) spinal cord on the right side. He had received radiation therapy (48 Gy) on his neck and mediastinum eight years previously due to adenocarcinoma of the right upper lung. Blood chemistry, CT of the spine, bone and gallium scintigraphy were unremarkable. In magnetic resonance imaging (MRI) of the thoracic cord, the gadolinium (Gd)-enhanced T1-weighted image showed abnormal signal intensities from Th 3 to Th 4 of the spine. Myelography revealed no abnormalities. Three months later, the patient became a complete spinal man below the level of Th 4. Gd-enhanced MRI of the thoracic cord, performed eleven months later, showed formation of a spindle-shaped cavity from Th 2 to Th 5 of the spine surrounded by a ring-shaped enhanced cord. Chronic progressive radiation myelopathy (CPRM) was diagnosed based on these clinical and MRI findings. This was a rare case in which MRI-confirmed cavity formation in the spinal cord appeared in a patient with CPRM.

Aged

[Muscle sympathetic nerve activity in patients with spinocerebellar degeneration without orthostatic hypotension].

Muscle sympathetic nerve activity (MSNA) was compared in 6 patients (age; 45-76 years old, 3 males and 3 females) with spinocerebellar degeneration (SCD) without orthostatic hypotension (OH) and in 10 (age; 38-78 years old, 3 males and 7 females) with other neurologic disorders (controls). MSNA was elicited from the peroneal nerve at the resting recumbent position by using a microneurographic method. MSNA, heart rate (HR) from the electrocardiogram and mean blood pressure (MBP) measured by Finapres were recorded simultaneously at rest and during the head-up tilting at 45 degrees. Although there were no significant differences in MBP and HR between both groups, burst rate (bursts per minute) and burst incidence (bursts per 100 heart beats) of MSNA in SCD patients were significantly decreased as compared with controls (p < 0.01). During the head-up tilting, responses in MBP and MSNA showed a tendency to decrease in SCD patients. We concluded that the sympathetic noradrenergic system might be potentially impaired in SCD patients without OH.

Aged

Cu/Zn superoxide dismutase-like immunoreactivity in Lewy body-like inclusions of sporadic amyotrophic lateral sclerosis.

Cu/Zn superoxide dismutase (SOD)-like immunoreactivity (LI) was found within Lewy body-like inclusions (LBIs) in the spinal cords of patients with sporadic amyotrophic lateral sclerosis (ALS) by using an antibody to human Cu/ZnSOD. LBIs were detected in the anterior horn cells in 10 of 20 patients with sporadic ALS. In each of these patients, 7 to 60% of LBIs showed Cu/ZnSOD-LI. No Cu/ZnSOD-LI was detected in intact neurons and glia in the 20 ALS patients, as well as in these cells in 10 normal control individuals. The skein-like inclusions and Bunina bodies, which were found in all of the 20 ALS cases, showed no Cu/ZnSOD-LI. Thus, Cu/ZnSOD appears to play roles in the production and/or degradation process of LBIs.

Aged

Muscle spasm induced sympathetic reflex bursts on microneurography in a case with pontine demyelination.

Microneurography was performed in a 39-year-old woman with demyelination of the pontine white matter associated with muscle spasms in the lower extremities. Single bursts on the microneurogram were observed immediately after cessation of the spasm with no systemic changes in the blood pressure or heart rate. Voluntary tonic flexion of the lower extremities induced similar bursts with small amplitudes. These reflex bursts possessed a characteristic of muscle sympathetic nerve activity, because the latency between the peak of each burst and the prior R-wave on the electrocardiograph was constant. The occurrence of these bursts suggests that a segmental compensatory mechanism in the spinal cord may stabilize the muscle blood flow influenced by muscle contraction.

Adult

Polymorphism of factor H (beta 1H globulin) in Japanese: description of a new allele.

Polymorphism of factor H (HF) was investigated in 1060 unrelated Japanese individuals using isoelectric focusing and immunoblotting. Besides 6 different HF types a null type and an unusual type were observed. The family analysis suggested the hereditary occurrence of a new variant allele HF*C. The population data fitted the Hardy-Weinberg equilibrium, assuming that the null allele HF*QO occurs commonly. The allele frequencies were HF*A = 0.407 +/- 0.011, HF*B = 0.491 +/- 0.011, HF*A1 = 0.011 +/- 0.002 and HF*QO = 0.091 +/- 0.006. The HF polymorphism in Japanese was shown to be controlled by the above 4 common alleles.

Alleles

[A case of central pontine myelinolysis and extrapontine myelinolysis during rapid correction of hypernatremia].

A 69-year-old woman was admitted because of severe dehydration due to anorexia. Consciousness disturbance was found to be due to severe abnormalities of serum electrolyte balance, but recovered quickly by correcting the hyperosmolality. While the initial serum sodium value of 186 mEq/L was corrected to 139 mEq/L in 5 days, locked-in syndrome, bilateral hand tremor and tetraparesis appeared. Brain magnetic resonance imaging (MRI) revealed symmetrically high signal intensity areas on T2-weighted images and low signal intensity areas on T1-weighted images in central part of pons and bilateral middle cerebellar peduncles. One and a half month later, these neurologic symptoms were improved and the MRI abnormalities also disappeared. Auditory brain stem responses which showed prolongations of III to V wave peak to peak latency at the onset returned to normal. It is noted in this case that central pontine myelinolysis (CPM) and extrapontine myelipolysis (EPM) appeared during the period of rapid correction of hypernatremia. Although it is known CPM and EPM are caused by hypernatremia or the rapid correction of hyponatremia, there has been reported only one case of CPM and EPM after rapid correction of hypernatremia. According to the hypothesis of Norenberg, rapid rise in serum sodium may cause CPM and EPM, but if CPM and EPM are caused by the rapid correction of hypernatremia in this case, CPM and EPM may be caused by another pathogenesis of the disorder.

Aged