Performance of a rapid human metapneumovirus antigen test during an outbreak in a long-term care facility.

Using a newly developed rapid test, an outbreak of human metapneumovirus (HMPV) infection in a long-term care facility was detected within only 2 days after the onset of symptoms in a putative index case. The outbreak was almost under control within 8 days mainly by zoning patients, with the exception of two cases of HMPV that were diagnosed 16 and 17 days after the onset of the outbreak. According to an immunological diagnosis as well as the rapid test, it was eventually proven that 18 patients had HMPV infections. We suspected that even asymptomatic residents, who had not been completely separated from the facility population, were a source of infection. That suggested that all asymptomatic residents should be tested and that the separation of the infected patients should be absolute, if an outbreak of HMPV infection is suspected in such a facility.

A novel immunoassay of smooth muscle myosin heavy chain in serum.

We have developed a double monoclonal sandwich enzyme immunoassay to measure smooth muscle myosin heavy chain (MHC). Analytical performance of the assay showed reliable detection of smooth muscle MHC in human sera. The mean of the smooth muscle MHC level in normal human sera was 0.9 +/- 0.9 ng/ml. In sera of patients with aortic dissection, the smooth muscle MHC level sharply elevated at the onset and rapidly decreased to normal levels. Immunoassay of smooth muscle MHC in serum is a promising method for biochemical diagnosis of smooth muscle disorders.

Tissue specificity in cytochrome c oxidase deficient myopathy.

Biopsied muscles were treated in 2 ways to demonstrate cytochrome c oxidase (CCO) activity on electron microscopy: (1) one to several muscle fibers were teased off the biopsy in buffer solution after glutaraldehyde fixation, (2) 20-30-microns thick cryostat sections were placed on precooled glass slides and fixed in glutaraldehyde solution at room temperature. After rinsing in buffer, the teased fibers and cryostat sections were stained with cytochrome c oxidase. In both procedures, almost all mitochondria in control muscle fibers stained positively. In CCO deficiency, the enzyme activity differed from tissue to tissue indicating marked tissue specificity. In the fatal infantile form enzyme activity in muscle fibers was absent, but present in fibroblasts, endothelial cells and smooth muscle arterial cells. The enzyme activity in other forms differed from cell to cell, but individual mitochondria in a given cell examined in cross-section showed uniform CCO activity, indicating that there was no intracellular mosaicism of enzyme positive and negative mitochondria.

Focal cytochrome c oxidase deficiency in various neuromuscular diseases.

To determine whether focal cytochrome c oxidase (CCO) deficiency characterized by scattered fibers with absent CCO activity among normal fibers was a specific finding for mitochondrial myopathies, we studied 389 muscle biopsies from various neuromuscular diseases other than mitochondrial myopathies. Focal CCO deficiency was found in 14 biopsies: 5 of 26 patients with myotonic dystrophy, 3 of 19 with nemaline myopathy, 1 of 7 with distal myopathy with rimmed vacuole formation, 3 of 22 with limb-girdle muscular dystrophy, 1 of 9 with amyotrophic lateral sclerosis, one of 79 with Duchenne muscular dystrophy. Focal CCO deficiency is known to be a crucial finding for chronic progressive external ophthalmoplegia, but it can also be seen in a variety of other neuromuscular disorders, probably as a secondarily induced phenomenon.

Serial magnetic resonance images in a patient with congenital sensory neuropathy with anhidrosis and complications resembling heat stroke.

We report the results of serial computerized tomography (CT) and magnetic resonance imaging (MRI) in a 9-month-old Japanese girl with the rare disorder, congenital sensory neuropathy with anhidrosis (CSNA). She developed a prolonged high fever, anorexia, and weight loss with laboratory findings of hemoconcentration and elevated levels of GOT, LDH and creatine phosphokinase (CK) in May 1995, and was hospitalized. The cerebrospinal fluid (CSF) was normal on admission. Elevation of CSF myelin basic protein on the 16th hospital day suggested a destruction of the myelin sheath. The first MRI performed on the 16th hospital day revealed no marked abnormalities when the patient exhibited a high fever, generalized tonic-clonic convulsions, and impaired consciousness. The patient had a persistent high fever, and developed a second generalized tonic clonic convulsion and became comatose. A second MRI on the 20th hospital day showed a bilateral symmetrical paracentral hypo-intensity of the white matter with occipital hypo-intensity on T2-weighted images. MRI findings were considered to represent the complications of the high fever with a loss of water from the cerebral cortices and deep white matter. MRI and CSF findings indicated the presence of brain damage due to the high fever.

Cerebrospinal fluid biopterin and biogenic amine metabolites during oral R-THBP therapy for infantile autism.

Treatment with 6R-L-erythro-5,6,7,8-tetrahydrobiopterin (R-THBP) has been suggested to improve autistic behavior. Cerebrospinal fluid (CSF) levels of total biopterin, oxidized and reduced forms of biopterin, homovanillic acid, and 5-hydroxyindoleacetic acid were measured in 14 autistic children and 18 controls to clarify the mechanism of action of R-THBP. The 14 autistic children received R-THBP orally at 1 mg/kg per day; 7 children showed clinical improvement (responders) and the other 7 patients did not (nonresponders). There were no significant differences between responders, nonresponders, and controls in the CSF levels of the metabolites before R-THBP administration. When lumbar puncture was repeated in 6 autistic children in the 24th week of R-THBP therapy, there was no significant change in the CSF levels of any metabolites.

CSF beta-endorphin levels in patients with infantile autism.

We measured CSF levels of beta-endorphin, an opioid hormone, in 19 patients with infantile autism and in 3 patients with Rett syndrome, and compared them with control values. In infantile autism, CSF levels of beta-endorphin did not differ significantly from those of age-matched controls. There was no significant correlation between CSF levels and clinical symptoms, including self-injurious behavior, pain insensitivity, and stereotyped movement. However, CSF levels of beta-endorphin were significantly higher in the patients with Rett syndrome than in the control (p < .05). Data suggest that neurons containing beta-endorphin may not be involved in patients with infantile autism. Thus, there is no relationship between dysfunction of brain opioid and autism.

Saccular aneurysm of pulmonary autograft after the Ross procedure.

The Ross procedure, which includes removal of the malformed aortic valve and replacement of a pulmonary autograft in the aortic position, has increased the number of available treatment options. Recently, dilatation of the autograft pulmonary root after the Ross procedure has been reported as a complication. We report a patient with bicuspid aortic valve malformations and aortic annulus dilatation, who had a saccular-form, true-type, aneurysm in the pulmonary autograft seven months after the Ross procedure. These changes have not been described so far as complication. Pathologically, marked mucoid degeneration was noted in the tunica media of the aneurysm, as well as in the original aortic root. These findings may suggest similar pathological characteristics between the aorta and pulmonary arteries. Hence, the surgical risks accompanying vascular characteristics in patients with congenital aortic valve malformations should be considered.

Turner syndrome and occlusion of the internal carotid artery.

A 2-year-old girl with Turner syndrome was admitted with left hemiplegia and left facial palsy. Serial cranial computed tomographic scan demonstrated multiple cerebral infarctions in the right putamen and right medial cortical areas. Single photon emission computed tomographic scan revealed hypoperfusion from the right frontal to the right temporal area. Right carotid angiography showed narrowing and occlusion of the right internal carotid artery at the sphenoidal portion. Collateral circulation was not detected between the external and internal carotid arteries. Left carotid angiography revealed that the left anterior artery was narrow, and that the left internal carotid artery provided blood to the right internal carotid artery through the anterior communicating artery. These findings suggested that the cerebrovascular abnormality might be due to congenital hypoplasia of arteries in this patient. The unusual combination of cerebral infarction and Turner syndrome was reported.

Secondarily reduced cytochrome c oxidase activity in various neuromuscular disorders.

Decreased cytochrome c oxidase (CCO) activity was found in various neuromuscular diseases, including infantile spinal muscular atrophy (SMA) and Fukuyama type congenital muscular dystrophy (FCMD), that was thought to result from a secondarily induced mitochondrial defect. To determine whether or not the enzyme activities in the mitochondrial electron transport system can be secondarily changed, we measured the enzyme activities in denervated rat muscles. The CCO activity decreased progressively to 38-47% of the control value in 3 weeks after denervation, the NADH-cytochrome c reductase and succinate-cytochrome c reductase activities remaining unchanged, suggesting that the CCO activity may be easily reduced secondarily in various disease conditions.

Long-term observation of the changing brainstem auditory evoked potentials in a case of infantile opsoclonus-polymyoclonia syndrome.

Brainstem auditory evoked potential (BAEP) studies were repeatedly carried out on a boy with infantile opsoclonus-polymyoclonia syndrome, from 15 months to 39 months of age, the following being revealed: the I-III interpeak latency (I-III IPL) was more or less in the upper normal range until 24 months and then remained at the same level throughout the rest of the observation period, not showing physiological shortening with maturation. It should be noted that the prolongation of I-III IPL continued in spite of the disappearance of the opsoclonus.

The differential diagnosis of Reye syndrome: muscle biopsy evaluation.

To evaluate the usefulness of muscle biopsy to obtain a diagnosis of Reye syndrome (RS), muscle biopsies were performed in 10 patients, with definite RS (1 patient) and mimicking RS (9 patients) (Table 1). The muscle biopsy results were compared with those of liver biopsies in 7 patients including one patient with definite RS and 6 with mimicking RS. In 3 clinical RS patients, only a muscle biopsy was performed. In the patient with definite RS, oil red O positive lipid droplets were mildly increased in type 1 fibers, with no morphological abnormality of muscle mitochondria, whereas the liver biopsy specimen showed both centrinuclear fatty metamorphosis and mitochondrial abnormality, i.e., a typical RS pathology. Marked lipid accumulation in type 1 fibers and morphological abnormality of muscle mitochondria were observed in two patients with systemic carnitine deficiency and one of two patients with fulminant hepatitis without jaundice who showed mimicking RS clinically. Therefore, it is difficult to make a diagnosis of RS simply on the basis of the clinical findings and muscle morphology.

Complete external ophthalmoplegia in a patient with congenital myopathy without specific features (minimal change myopathy).

An 11-month-old female infant with mild asphyxia at birth had severe generalized muscle hypotonia and weakness, predominantly in the neck flexors, a high-arched palate and a funnel chest from early infancy. Her facial muscles were also markedly involved. In addition, she showed striking non-progressive, complete external ophthalmoplegia and mild ptosis. A muscle biopsy specimen showed non-specific myopathic changes, including mild variation in fiber size, mild type 1 fiber predominance, type 2B fiber deficiency and slightly increased acid phosphatase activity. Complete ophthalmoplegia may thus be seen not only in myotubular myopathy but also in various forms of congenital non-progressive myopathy.

The Rett syndrome and CSF lactic acid patterns.

We investigated both blood and cerebrospinal fluid (CSF) lactate and pyruvate levels in seven girls with the Rett syndrome (RS) and evaluated the relationship between CSF lactate and pyruvate levels and the clinical manifestations, particularly seizures, anticonvulsant medication, and breathing dysfunction including breath holding, apnea and hyperventilation. Elevated lactate and pyruvate levels in CSF with normal serum lactate were found in two RS patients. Elevated CSF lactate correlated significantly with the clinical occurrence of hyperventilation (P0 = 0.048, Fisher exact probability). We measured native and dichloroacetate (DCA)-activated pyruvate dehydrogenase (PDH) complex activities in two patients (#1 and 2) using cultured lymphoblastoid cell lines which were transformed by EB virus and the results were normal. We also analyzed CSF citric acid intermediates from 7 RS patients including citric acid, cis-aconitate, alpha-ketoglutarate, succinate, fumarate, malate and oxaloacetate. These concentrations were not significantly different from those control patients (N = 21). An elevated lactate level may be a clue to clarify the etiology of RS.

Acute disseminated encephalomyelitis after Japanese B encephalitis vaccination.

A 6-year-old girl (Patient 1) and a 5-year-old boy (Patient 2) with acute disseminated encephalomyelitis after Japanese B encephalitis vaccination are reported. Drowsiness, paresthesias, and gait disturbance were observed at 14 days (Patient 1) and 17 days (Patient 2) after the vaccination; however, transient impairment of visual acuity was only found in Patient 1. Laboratory examinations revealed slow theta waves on electroencephalography and elevated myelin basic protein in the cerebrospinal fluid in both patients. The most striking feature on magnetic resonance imaging was the combination of white matter lesions and abnormal intensity signals of the thalamus. The administration of oral prednisolone (2 mg/kg/day) markedly improved the clinical findings and abnormal magnetic resonance imaging findings. A similar magnetic resonance imaging finding of abnormal intensity of the thalamus with deep white matter lesions has been reported in patients with Japanese B encephalitis; therefore, thalamic lesions may be related to the naturally occurring encephalitis.