Identification of the spinocerebellar ataxia type 2 gene using a direct identification of repeat expansion and cloning technique, DIRECT.

Spinocerebellar ataxia type 2 (SCA2) is an autosomal dominant, neurodegenerative disorder that affects the cerebellum and other areas of the central nervous system. We have devised a novel strategy, the direct identification of repeat expansion and cloning technique (DIRECT), which allows selective detection of expanded CAG repeats and cloning of the genes involved. By applying DIRECT, we identified an expanded CAG repeat of the gene for SCA2. CAG repeats of normal alleles range in size from 15 to 24 repeat units, while those of SCA2 chromosomes are expanded to 35 to 59 repeat units. The SCA2 cDNA is predicted to code for 1,313 amino acids-with the CAG repeats coding for a polyglutamine tract. DIRECT is a robust strategy for identification of pathologically expanded trinucleotide repeats and will dramatically accelerate the search for causative genes of neuropsychiatric diseases caused by trinucleotide repeat expansions.

Hypertrophic cardiomyopathy in congenital myotonic dystrophy.

Involvement of the cardiac conduction system is a common clinical feature in myotonic dystrophy, whereas the association of primary myocardial abnormalities has rarely been reported. A patient with a severe form of congenital myotonic dystrophy who developed fatal left ventricular hypertrophy at 3 months of age and died at 2 years of age is reported. Serial ultrasonographic studies revealed progressive left ventricular hypertrophy accompanied by outflow obstruction of the left ventricle. Southern analysis for the myotonin kinase gene revealed a 5.8 kb expansion of CTG repeats in addition to a fragment of normal length. The degree of expansion was much greater than those of other reported patients with congenital myotonic dystrophy. These findings suggest that left ventricular hypertrophy represents an extreme level of myocardial damage in myotonic dystrophy and that this damage may be related to the larger size of the CTG repeats.

[The clinical features of patients with probable dementia with Lewy bodies--report of 4 cases].

Recently, McKeith et al. proposed criteria for the clinical diagnosis of dementia with Lewy bodies (DLB). In our study the clinical features of four patients with progressive dementia, visual hallucinations, delusions, and parkinsonism were compatible with those of DLB. To evaluate the neurological and psychiatric features, responses to medications, magnetic resonance imaging (MRI), and single-photon emission computed tomography (SPECT) in patients with DLB, we compared the above DLB patients with age- and gender-matched Parkinson's disease patients showing no signs of dementia. Our DLB patients presented with mild tremor, moderate rigidity and akinesia, severe constitutional dysfunction and recurrent visual hallucinations and delusions. These psychiatric symptoms became worse by anticholinergic agents and dopamine agonists and were difficult to control using neuroleptic medications. MRI revealed atrophy of the cerebrum to be more accentuated in the parietal region. SPECT demonstrated hypoperfusion in the parietal and occipital lobes. These findings suggest that parietal lobe dysfunction is a feature of DLB. It may, therefore, be concluded from this study that brain MRI and SPECT are useful in the clinical diagnosis of DLB, and that great caution should be taken when prescribing longacting dopamine agonists and neuroleptics to such patients.

[Correlation between degrees of the CTG repeat expansion and clinical features of myotonic dystrophy].

The mutation in myotonic dystrophy gene has recently been identified as an unstable expansion of trinucleotide CTG repeat located at the 3'-untranslated region of myotonin protein kinase gene. In this paper we report the correlation between the degree of CTG amplification and clinical features in 35 individuals with myotonic dystrophy. The analysis of CTG repeat expansion was performed with Southern blot hybridization. Genomic DNA from peripheral blood leukocytes was digested with a restriction endonuclease, Pst I, instead of commonly used EcoRI. Since small expansion (about 100 bp) could be detected with PstI digestion and furthermore, the DNA fragment did not contain insertion/deletion polymorphism, we were able to accurately determine the exact sizes of CTG repeat expansion. We have observed a tendency of earlier ages of onset with larger allele sizes. The good correlation between the size of the expansion and the severity in muscle weakness was clearly demonstrated especially if the analysis was focused on the patients at same age group at 40-45 years. The severity of motor disability was classified into three stages. The mean size of expansion was 0.33 +/- 0.17 (M +/- SD) kbp in stage I, 2.58 +/- 1.42 kbp in stage II, and 4.75 +/- 0.93 kbp in stage III. The tendency was also observed when patients were categorized according to the intellectual grade. The anticipation was observed in all the parent-child pairs. When the increases of the repeat expansions were compared between father-child and mother-child transmissions, broader variation of the increases was observed in father-child transmissions.(ABSTRACT TRUNCATED AT 250 WORDS)

[A case of chronic enteroviral meningitis and hydrocephalus associated with Bruton type agammaglobulinemia].

We report a 10-year-old boy with chronic enteroviral meningitis associated with agammaglobulinemia (CEMA) and hydrocephalus. He was treated with a low-dose intravenous administration (100 mg/kg/4 weeks) of gammaglobulin (gamma-gl) since he was diagnosed as having Bruton type agammaglobulinemia at 1 year of age. At this admission, neurological examination revealed meningeal signs, Babinski sign, frontal signs, urinary incontinence, and mental retardation (IQ = 48) which was considered to be a sequela of the enteroviral encephalitis which had occurred in his first year of life. T 1-weighted MR imaging of the brain following gadolinium administration revealed a marked dilatation of the lateral ventricles and dense enhancement of the meninges. Enterovirus was detected in the cerebrospinal fluid (CSF) using tissue culture. Histological examination of a biopsied leptomeningeal specimen revealed inflammatory thickening, which was a likely cause of the obstruction to the flow of CSF. The hydrocephalus in this patient was treated with external drainage of CSF from the lateral ventricle. The CEMA was brought into remission by means of the intraventricular administration of gamma-gl, at a dose of 125-250 mg/week (total dose: 1.5 g/8 weeks), in addition to the high dose intravenous administration (400 mg/kg/4 weeks) of gamma-gl. Because of the poor prognosis of patients with CEMA, the intraventricular administration of gamma-gl should be initiated immediately following a diagnosis of enteroviral meningitis.

[Computed cranial tomography, magnetic resonance imaging and brain echo imaging in Japanese B encephalitis].

We reported computed cranial tomography (CCT), magnetic resonance imaging (MRI) and brain echo imaging in Japanese B encephalitis. The result were assessed in comparison with the clinical feature of the disease. CCT of the three patients showed low density in thalamus and basal ganglia. In two, the lesions were detected in the acute phase, and changed to high density in the chronic phase. Their prognosis was poor, psychomotor delay and paresis persisted. Among the previously reported sixteen patients of Japanese B encephalitis in Japan, the four developed thalamic lesions on CCT and the prognosis was poor in all patients. Brain echo detected the lesions in the acute phase before CCT visualised them clearly. MRI demonstrated thalamic hemosiderin deposits and calcification. These findings were compatible with the pathological findings, or past hemorrhage and organization. The distribution of the lesion were closely connected with the prognosis.

[Effect of maternal paternal transmissions on clinical manifestations of CTG repeat on myotonic dystrophy].

The increasing size of the CTG repeat in successive generations is considered to the molecular basis for anticipation in DM. Maternal offspring show severe clinical manifestation than paternal transmitted offspring. The intergenerational amplification of this repeat is influenced by the sex of the parent transmitting mutant allele, in that a greater average intergenerational amplification is seen on maternal transmission. Also in the severest form of CDM almost exclusively transmitted maternal allele, the number of repeats is generally higher than that seen in non-CDM. But whether the unknown another maternal factor influence defined children having large mutant allele from mother is important question. The parental bias based on the different methylation patterns, mitochondria genome or different expressions of mRNA species are unlikely. The maternal effect might be explained the differences of the expressions of mRNA according to alternating splicing. And intrauterine effect, chromosomal imprinting or other unknown maternal factors have been expected to be involved in the pathophysiology.

[Lysosome disease--Sandhoff disease].

Lysosomal beta-hexosaminidase occurs as two major isozymes hexosaminidase A and B. The alpha subunit is encoded by the HEXA gene and the subunit by HEXB gene. Defects in the beta subunit lead to Sandhoff disease. Patients with the defect lack the activity or formation of both hexosaminidase A and B. The disorders are classified according to the age of onset, as infantile, juvenile and adult form. Recent molecular genetic analysis has revealed a 50 kb deletion, 16 kb Alu type deletion, and compound heterozygous with other mutations. In the juvenile or adult type of the disease, point mutation of the HEXB gene, creating a new 3' splice acceptor site. The correlation of the clinical phenotype and the gene abnormalities is discussed.

Direct detection of expanded (CAG/CTG) repeats in the myotonin-protein kinase genes of myotonic dystrophy patients using a high-stringency hybridization method.

Recent discoveries of genes containing (CAG/CTG) repeats as the causative genes for neuromuscular diseases suggest that trinucleotide repeat expansions are associated with a number of other neurodegenerative diseases, particularly in those showing genetic anticipation. In order to efficiently identify expanded trinucleotide repeats, we have developed a novel method using a single-stranded probe containing (CAG)55, which allows direct detection of expanded (CAG/CTG) repeats in the myotonin-protein kinase (Mt-PK) genes of patients with myotonic dystrophy without the need for any prior information of chromosomal localizations of the disease genes. This method is expected to be useful for identifying novel genes for diseases associated with expanded (CAG/CTG) repeats.

General pharmacological properties of the human corticotropin-releasing hormone corticorelin (human).

General pharmacological effects of the human corticotropin-releasing hormone, corticorelin (human) (CAS 86784-80-7), on the central nervous system, somatic nervous system, autonomic nervous system and smooth muscle, respiratory and circulatory system, digestive system and miscellaneous organs were investigated. 1. The central nervous system: Corticorelin (human) had little effect on hexobarbital-induced sleeping-time, maximal electroshock-induced convulsion, acetic acid-induced writhing, rota-rod performance. Corticorelin (human) at doses of more than 10 micrograms/kg i.v. induced flush of skin and pilo-erection, at doses of more than 30 micrograms/kg i.v. decreased body temperature, delayed expression of perphenazine-induced catalepsy and indicated hunched posture, and at the dose of 100 micrograms/kg i.v. induced the rise of awake-level and decrease of the total power of EEG, and decreased the spontaneous motor activity. 2. The somatic nervous system: Corticorelin (human) did not cause muscle relaxation in mice and had little effect on neuromuscular transmission in rats. No local anesthetic activity of corticorelin (human) was exhibited through inhibition of the corneal reflex in guinea pigs. 3. The autonomic nervous system and smooth muscle: Corticorelin (human) had no effect on the contraction of isolated ileum of guinea pigs induced by histamine and acetylcholine, and on the contraction of isolated trachea of guinea pigs induced by histamine, and the pupil diameter of rabbits. Corticorelin (human) at doses more than 30 micrograms/kg i.v. decreased spontaneous motility and contractile force of uterus of non-pregnant rabbits. 4. The respiratory and circulatory system: Corticorelin (human) had no effect on the contraction of isolated aorta of rats induced by norepinephrine. Corticorelin (human) at doses of more than 3 micrograms/kg i.v. decreased the blood pressure, increased heart rates and slightly increased the number of respiration in dogs. However, corticorelin (human) had no effect on ECG and femoral blood flow in dogs. 5. The digestive system: Corticorelin (human) at doses of more than 0.3 microgram/kg i.v. increased duodenal motility and contractile force, at doses of more than 1 microgram/kg i.v. increased colonic contractile force transiently and increased antral motility. Corticorelin (human) at doses of more than 3 micrograms/kg i.v. caused diarrhea and at doses of more than 30 micrograms/kg i.v. inhibited small intestinal propulsion in mice. Corticorelin (human) at dose of 100 micrograms/kg i.v. showed an inhibition of the gastric juice secretion and decreased the excretion of Na+, Cl- and H+ in rats. Corticorelin (human) produced slight gastric damages only at the highest dose of 100 micrograms/kg i.v.(ABSTRACT TRUNCATED AT 400 WORDS)

Juvenile-onset generalized neuroaxonal dystrophy (Hallervorden-Spatz disease) with diffuse neurofibrillary and lewy body pathology.

We describe an unusual case of Hallervorden-Spatz disease (HSD). After presenting with limb rigidospasticity at the age of 9 years, our patient developed progressive dementia, spastic tetraparesis and myoclonic movements, leading to akinetic mutism. He died of pneumonia at the age of 39 years. Autopsy revealed a severely atrophic brain, weighing 510 g. Histologically, there were iron deposits in the globus pallidus and substantia nigra pars reticulata, and numerous axonal spheroids throughout the brain and spinal cord. Neurofibrillary tangles were abundant in the hippocampus, cerebral neocortex, basal ganglia and brain stem. Neuritic plaques and amyloid deposits were absent. Lewy bodies and Lewy neurites, which were immunolabeled by anti-alpha-synuclein, were found in the brain stem, cerebral cortex and spinal gray matter. Sarkosyl-insoluble tau extracted from the temporal cortex resolved on immunoblots into three major bands of 60, 64 and 68 kDa and a minor band of 72 kDa, as reported for Alzheimer's disease. The present case, together with a few similar cases reported previously, may represent a particular subset of neuroaxonal dystrophy, i.e., HSD associated with extensive accumulation of both tau and alpha-synuclein.