Kainic acid may enhance hippocampal NO generation of awake rats in a seizure stage-related fashion

Temporal changes in kainate-induced seizure activity and hippocampal NO generation were evaluated simultaneously in conscious rats by using in vivo microdialysis and by determining the concentrations of nitrite and nitrate in perfusates. Intraperitoneal injection of kainic acid produced 'wet dog shake', focal seizure of the limbs and neck, hypersalivation, or generalized convulsion. These behavioral changes peaked at 120 min after the drug challenge and lasted for about 100 min. In contrast, the concentrations of NO metabolites, nitrite and nitrate, in the hippocampal perfusates increased rapidly and reached a plateau level at 40 min after the injection, and the level remained high for over 220 min. The increase was more marked in animals presenting severe seizures than those presenting mild ones. Pre-treatment with 25 mg/kg N(G)-nitro-L-arginine methyl ester promoted the severity of kainate-induced seizures, but it suppressed the increase in NO metabolites. These results suggest that kainic acid enhances hippocampal NO generation in a severity-related manner of the induced seizures. The enhanced NO generation upon kainate challenge appears mainly to be involved in seizure suppression.

Immunostaining of dystrophin and utrophin in skeletal muscle of dystrophinopathies

Immunostaining of biopsied skeletal muscle of 4 Duchenne (DMD), 12 Becker muscular dystrophy (BMD) and 3 DMD carriers' was performed using monoclonal antibodies against dystrophin and utrophin. In DMD, dystrophin-negative staining was observed except for revertant fibers which showed different stain patterns for each antibody. In 7 BMDs, there was faint/patchy stain in cases of deletion between exons 45-52, while in one case there was deletion between exons 12-17 and no stain was noted relevant to the deletion site. Moreover, in 2 cases of undetectable deletion, antibodies which recognize a terminal portion of the C-terminal domain revealed the absent stain. In DMD, the utrophin-positive fibers corresponded to dystrophin-negative fibers. In BMD, this relationship did not necessarily occur in each fiber. In DMD carriers, a cluster of dystrophin-negative fibers which was positive for utrophin were prominent. In dystrophinopathy, the immunostaining of dystrophin and utrophin is useful, in combination with dystrophin gene analysis to make a definite diagnosis.

L-DOPA does not facilitate nitric oxide production in the rat striatum and substantia nigra: in vivo microdialysis study

Using in vivo microdialysis and flow-injection, we evaluated the production of nitric oxide (NO) in the striatum and substantia nigra of freely moving rats in response to challenge doses of L-dihydroxyphenylalanine (L-DOPA) by measuring the NO metabolite levels of nitrate and nitrite. The dopamine and 3,4-dihydroxyphenylacetic acid (DOPAC) concentrations also were determined in the same perfusates. Intraperitoneal injection of L-DOPA produced a significant, dose-dependent increase in the extracellular levels of dopamine and DOPAC in these areas, but did not modify the extracellular levels of the NO metabolites. An acute dose of L-DOPA does not appear to facilitate NO production in the rat striatum and substantia nigra.

Application of a novel fluorescence intensity assay: identification of distinct fatty acetates as volatile compounds that bind specifically to amino acid region 149-168 of a transmembrane receptor CD36

The cluster of differentiation 36 (CD36) is a transmembrane receptor expressed in various cells and has diverse lipid ligands. The expression of CD36 in the murine olfactory epithelium and its ability to recognize certain species of fatty aldehydes, a class of odor-active volatile compounds, have suggested a role for this receptor in the capture of specific odorants in the nasal cavity of mammals. However, the spectrum of CD36-recognizable volatile compounds is poorly understood. In this study, we employed our recently devised assay with fluorescently labeled peptides as probes (fluorescence intensity assay) and identified distinct fatty acetates as volatile compounds that bind specifically to amino acid region 149-168 of CD36 (eg dodecyl and tetradecyl acetates). The present findings demonstrate the utility of our assay for the discovery of novel CD36 ligands and support the notion that the receptor functions as a captor of volatile compounds in the mammalian olfactory system.

Inflammatory demyelinating polyradiculoneuropathy associated with interstitial lung disease

A 58-year-old woman presented with inflammatory demyelinating polyradiculoneuropathy accompanied by sensory and motor disturbance and interstitial lung disease. Corticosteroid therapy led to a marked amelioration of both the neuropathy and the lung disease. We suggest that a demyelinating neuropathy is associated with an interstitial lung disease.

[Immunostaining of mitochondrial heat shock proteins (mtHSPs) in skeletal muscle fibers of mitochondrial cytopathy]

Expression of the mtHSPs (HSP60 and mtHSP70) was immunohistochemicall observed in biopsied limb muscles of genetically determined mitochondrial cytopathies (chronic progressive ophthalmoplegia 14, MELAS 4, limb girdle syndrome with the A-to-G transition at nt.3243 of tRNALeu(UUR), exertional myoglobinuria with multiple deletions of mtDNA 2, and Leber's hereditary optic neuropathy 2). mtHSP 70 and HSP 60 were strongly localized at ragged-red fibers. In strongly succinate dehydrogenase-reactive vessels of MELAS, mtHSP70 was expressed. GRP78 was expressed in the cytoplasmic body, which is often observed in this disorder. The present data suggest that expression of mtHSPs may reflect increased numbers of mitochondria, an impairment of assembly of mitochondrial proteins encoded by the genomic DNA and abnormal mitochondrial DNA, and/or an impaired mitochondrial function due to recurrent oxygen radical attacks against mitochondria.

[Acquired unilateral blepharoptosis by wearing contact-lenses in young adult women]

Four young unmarried women developed unilateral non-fluctuating blepharoptosis by wearing contact-lenses. Past and family histories were unremarkable. Blepharoptosis insidiously occurred within a few years after wearing lenses. Contralateral lid was quite normal. No abnormalities was observed in pupils, extraocular muscles, ocular positioning and other systems. So far recognized causes of blepharoptosis were ruled out through extensive clinical and laboratory observations. Improvement was insufficient even after wearing lenses off. Pathogenesis is probably due to repeated minor trauma to the levator palpebral muscle and its tendon secondary to frequent wearing on/off contact-lenses.

[Corticosteroid responsive inflammatory myopathy with autoantibody against Golgi apparatus]

A 51-year-old woman of progressive myopathy predominantly involving proximal groups of limb-muscle was reported. Serum enzymes originating from the skeletal muscle always remained within normal range, and a positive autoantibody against Golgi apparatus and the SS-A (Ro) antibody in serum were noted. In muscle biopsy performed twice, extensive degenerating/regenerating fibers and sparce inflammatory cells between connective tissue elements in light microscopy, and disrupted lamellar structure of Golgi apparatus in electron microscopy were observed. Corticosteroid therapy was markedly effective. In the present case of a "so-called" limb-girdle syndrome, humoral autoantibodies, especially against Golgi apparatus, could induce a metabolic disturbance in the muscle fiber.

[A case of erythroleukemia found after multiple cerebral hemorrhage]

A 61-year-old man without hypertension was admitted for unconsciousness. Brain CT showed multiple cerebral hemorrhage of the left frontal lobe and right occipital lobe. The hemoglobin was 7.0 g/dl, the platelet count 7,000, the white-cell count 7,600 with erythroblasts, and the fibrinogen 327 mg/dl. No disseminated intravascular coagulation was found. Bone marrow examination demonstrated 69.2% erythroblasts including abnormal types of nucleus, 12.8% myeloblasts, 12.8% neutrophils, 0.8% monocytes, 4% lymphocytes, and 0.4% reticulocytes. Chromosomal examination showed 7 of 20 bone marrow cells were variously abnormal. A diagnosis of erythroleukemia with major karyotype aberrations (MAKA) was made. The patient died 5 days after admission. Histologically, cerebral hemorrhagic lesions showed complete necrosis, but neither invasion of leukemic cells nor amyloid angiopathy. We suspected that the cause of cerebral hemorrhage was severe loss of platelets. This is a rare case of erythroleukemia found after multiple cerebral hemorrhage. As a cause of cerebral hemorrhage in an old man without hypertension, one should consider not only cerebral amyloid angiopathy but also leukemia.