Tetsuya Kibe

C/EBPα is required for differentiation of white, but not brown, adipose tissue

The transcription factor CCAAT enhancer binding protein α (C/EBPα) is expressed at high levels in liver and adipose tissue. Cell culture studies show that C/EBPα is sufficient to trigger differentiation of preadipocytes into mature adipocytes, suggesting a central role for C/EBPα in the development of adipose tissue. C/EBPα knockout mice die within 7–12 h after birth. Defective gluconeogenesis of the liver and subsequent hypoglycemia contribute to the early death of these animals. This short life span impairs investigation of the development of adipose tissue in these mice. To improve the survival of C/EBPα−/− animals, we generated a transgenic line that expresses C/EBPα under the control of the albumin enhancer/promoter. This line was bred into the knockout strain to generate animals that express C/EBPα in the liver but in no other tissue. The presence of the transgene improved survival of C/EBPα−/− animals almost 3-fold. Transgenic C/EBPα−/− animals at 7 days of age show an absence of s.c., perirenal, and epididymal white fat despite excess lipid substrate in the serum, whereas brown adipose tissue is somewhat hypertrophied and shows minimal biochemical alterations. Interestingly, mammary gland fat tissue is present and exhibits normal morphology. The absence of white adipose tissue in many depots in the presence of high serum lipid levels shows that C/EBPα is required for the in vivo development of this tissue. In contrast, brown adipose tissue differentiation is independent of C/EBPα expression. The presence of lipid in brown adipose tissue serves as an internal nutritional control, indicating that neither nutritional intake nor lipoprotein composition is likely responsible for the absence of white fat.

Refractory epilepsy accompanying acute encephalitis with multifocal cortical lesions: Possible autoimmune etiology

We report on a 14-year-old male suffering from acute encephalitis, whose clinical course met the criteria for acute encephalopathy with refractory, repetitive partial seizures (AERRPS). He presented with extremely refractory partial and secondary generalized seizures, and required high-dose barbiturate infusion therapy for 57 days under mechanical ventilation. Seven weeks after onset, the seizures were ameliorated by treatment with sodium bromide, carbamazepine, clobazam, and high-dose phenobarbital. Magnetic resonance imaging on day 14 of admission showed multifocal cortical lesions scattered in the bilateral hemispheres; these disappeared on day 34. Diffuse and mild atrophy of the cerebral cortex, and moderate atrophy of the hippocampus, appeared by day 61. Serum anti-glutamate receptor epsilon2 autoantibodies were detected on day 2. The patient was discharged after 113 days of admission with intractable epilepsy, memory disability, and regression of intelligence. We discuss the etiological significance of the multifocal lesions, which are unusual findings on neuroimaging of AERRPS.

Diffuse central nervous system lupus involving white matter, basal ganglia, thalami and brainstem

We described an 11-year-old girl with acute central nervous system lupus showing diffuse lesions. She developed generalized convulsions followed by prolonged coma, and her psychomotor ability recovered fully after 3 months of steroid therapy. Cranial magnetic resonance imaging (MRI) showed high signal intensity in the cerebral deep white matter, bilateral basal ganglia, thalami, and brainstem on T2-weighted image. These lesions resolved over 1 month with residual atrophic change in the heads of the caudate nucleus on MRI. Acute SLE leukoencephalopathy may be recognized as a subtype of CNS lupus.

Two concurrent chromosomal aberrations involving interstitial deletion in 1q24.2q25.2 and inverted duplication and deletion in 10q26 in a patient with stroke associated with antithrombin deficiency and a patent foramen ovale

Advanced high‐throughput molecular cytogenetic analysis has enabled the identification of small chromosomal rearrangements, and two or more concurrently occurring chromosomal rearrangements have been identified using this technique. A girl with severe psychomotor developmental delay associated with an uncertain abnormality (detected by conventional karyotyping) in chromosome 10q had a sudden stroke at the age of 35 months. Laboratory and radiographic examinations revealed antithrombin (AT) deficiency and a patent foramen ovale (PFO). Two concurrent chromosomal aberrations, inverted duplication and deletion in the 10q26 region and a microdeletion in the 1q24.2q25.2 region including the AT gene (SERPINC1), were identified by microarray‐based comparative genomic hybridization analysis. Both chromosomal aberrations were found to be of paternal origin. This study described the concurrence of chromosomal rearrangements involving two chromosomes, and estimated the frequency of two or more chromosomal aberrations as 2–4%.

Deletion of small nuclear ribonucleoprotein polypeptide N (SNRPN) in Prader‐Willi syndrome detected by fluorescence in situ hybridization: Two sibs with the typical phenotype without a cytogenetic deletion in chromosome 15q

The small nuclear ribonucleoprotein polypeptide N (SNRPN) gene is regarded as one of the candidates for Prader-Willi syndrome (PWS). We describe two sibs with typical PWS presenting deletion of SNRPN detected by fluorescence in situ hybridization (FISH). Neither a cytogenetically detectable 15q12 deletion nor a deletion for the D15S11, D15S10, and GABRB3 cosmid probes were found in either patient. This implies a smaller deletion limited to the PWS critical region. FISH with a SNRPN probe will permit analysis of PWS patients with limited deletions not detectable with other probes.

Automated determination of orotic acid, uracil and pseudouridine in urine by high-performance liquid chromatography with column switching

A column-switching high-performance liquid chromatographic method, requiring no sample preparation apart from filtration, is described for quantification of urinary orotic acid, uracil and pseudouridine. The analyses were carried out using a reversed-phase octadecylsilane-bonded column for sample clean-up and a cation-exchange column for separation; 5-20 microliters samples of urine were directly analysed, and more than 100 samples could be analysed consecutively. Each sample required only 30 min. Detection limits of these compounds were 5 pmol. Creatinine-related urinary uracil excretion was lowest in the newborn period (17.3 +/- 14.4 mumol/g of creatinine). A patient with partial ornithine transcarbamylase deficiency and his mother usually excreted a high level of uracil during the period of normal orotic acid excretion and normal serum ammonia level.

A novel PLP mutation in a Japanese patient with mild Pelizaeus-Merzbacher disease

Pelizaeus-Merzbacher disease (PMD) is a rare dysmyelinating disorder due to mutations in the proteolipid protein (PLP) gene. PLP gene mutations are responsible for a broad spectrum of disease, from the most severe form, connatal PMD, to a less severe form, spastic paraplegia 2 (SPG2). We describe here a very mild case of PMD in a patient who presented with nystagmus in early infancy and was unable to walk until 1 year 7 months of age. Brain magnetic resonance imaging (MRI) at 1 year 7 months of age revealed white matter abnormalities typical of PMD. Genetic testing revealed a novel mutation of the PLP gene (Gly197Arg). The patient presented with only mildly ataxic gait and slurred speech at the age of 4 years. Gly197Arg is the first novel mutation located within exon 4 of the PLP gene and associated with mild PMD/SPG2 in a Japanese patient.

Serial MRI findings of benign poliomyelitis

A 14-year-old boy presented with incomplete transverse myelopathic symptoms associated with mild encephalitis. Magnetic resonance imaging (MRI) revealed involvement of the central portion of spinal cord extending from the C1 to T5 level on T2-weighted images with expansion of the cervical spinal cord. The boy made a full clinical recovery in a few weeks. Cultures of the pharyngeal exudate were positive for ECHO virus type 11. The lesion on MRI disappeared completely in a few months.

Congenital muscular dystrophy caused by integrin α7 deficiency

SIR–Hayashi et al. reported three male children with integrin a7 deficiency. The first patient in this series had splice mutations on both alleles of the integrin a7 gene, rolled over at 9 months, walked at 2 years 6 months, and could not jump or run. Learning disability* was also observed, and the patient could speak only a few words. The second patient, a compound heterozygote for the same base deletion, acquired independent ambulation at 2 years 1 month and could not run. The third patient showed marked reduction of integrin a7 mRNA. He was born by Cesarean section because of breech presentation. His gestational age was 39 weeks, and his birth weight was 3024g. He had no family history of muscular disease. Hypotonia was seen from birth. The head was steady at 8 months, he sat without support at 1 year 2 months, and he moved on his knees at 2 years 8 months. His motor development then stopped and started regressing at age 5 years. Muscle weakness and atrophy, predominantly of the proximal muscles, progressed. No abnormalities were found on magnetic resonance imaging of the head. On histology, the muscles from these three patients showed little or no evidence of myofiber necrosis and regeneration. There have been no reports of the long-term clinical course of this disease. In order to determine the prognosis of this disease, we describe the clinical course of the third patient. The patient could only move by bottom shuffling at 7 years of age and he showed gradually progressive dyspnea at 8 years 10 months. He was admitted to Seirei Mikatahara General Hospital, Shizuoka, Japan, at 8 years 11 months after developing marked dyspnea. His vital signs were: temperature, 36.5 C; heart rate, 128 beats ⁄ min; respiratory rate, 28 breaths ⁄ min. Normal vesicular breath sounds were heard in both lungs, the heart sounds were normal, and no murmurs were heard. Laboratory data showed: white blood cell count, 10,900 ⁄ll; red blood cell count, 441 · 10 ⁄ll; hemoglobin, 12.3 g ⁄ dl; hematocrit, 40.7%; platelets, 31.3 · 10 ⁄ll; aspartate aminotransferase, 31 IU ⁄ L; alanine aminotransferase, 17 IU ⁄ L; lactate dehydrogenase, 258 IU ⁄ L; creatine kinase, 259 IU ⁄ L; creatinine, 0.1 mg ⁄ dl; blood urea nitrogen, 10 mg ⁄ dl; sodium, 140 mEq ⁄ L; potassium, 4.3 mEq ⁄ L; chloride, 99 mEq ⁄ L; and human atrial natriuretic peptide, 44 pg ⁄ ml. Blood gas analysis revealed: pH 7.266; PaCO2 79.4 mmHg; PaO2 62.4 mmHg; HCO3 36.1 mEq ⁄ L; base excess 7 mEq ⁄ L; and SpO2 87.3%. No infiltration was apparent on chest X-ray and marked scoliosis prevented us from measuring the cardiothoracic ratio. The Cobb angle was 73 . On cardiac ultrasound, the left ventricular end-diastolic dimension was 30.5 mm, the end-systolic dimension was 19.7 mm, and fractional shortening was 35.6%. We concluded that the dyspnea was caused by respiratory muscle weakness, since his cardiac function was normal. Non-invasive positive pressure ventilation was started, and his dyspnea improved. The patient was discharged from hospital 8 days later. The patient became wheelchair-bound at 12 years of age. His scoliosis was progressive, and his mental development was normal throughout life. His intelligence quotient (IQ) as evaluated using the Wechsler Preschool and Primary Scales of Intelligence at 6 years and 1 month showed: Verbal IQ 86; Performance IQ 123; and Total IQ 104. The basal lamina of the muscle fibers is important in the development and function of skeletal muscle, and integrin a7b1D is a muscle-specific laminin receptor. In a previous report, integrin a7 deficiency was categorized as ‘congenital myopathy’ because this disorder is thought to result from abnormal muscle development. We found that very severe cases of integrin a7 deficiency exist. The severity of this manifestation in the present case was almost equal to that of Duchenne muscular dystrophy; though hypotonia was seen soon after birth, cardiac function has remained unimpaired, and the patient’s intelligence is normal. We must keep integrin a7 deficiency in mind when we encounter patients with unclassified congenital muscular dystrophy or congenital myopathy. More cases must be collected, and further studies are needed.

Automated Quantitative Analysis for Orotidine and Uridine/Thymine in Urine by High-Performance Liquid Chromatography with Column Switching

The measurement of urinary orotidine, uridine and thymine which are intermediates in pyrimidine biosynthesis, is important for screening and diag-nosis inborn ergors of metabolism, such as urea cyclel and pyrimidine metabo-lism disorders 2 , as well as the measurement of urinary orotic acid and uracil l,3. Several high-performance liquid chromatography (HPLC) methods have been reported by a number of researchers. However, these HPLC methods for uridine and thymine analysis require rather complicated sample preparation in order to obtain accurate results 1. Although, a simple method for measuring orotidine and orotic acid were recently reported 4, it is not capable of evaluating near-normal levels of orotidine.