Pure alexia from a posterior occipital lesion.

The authors report a patient with pure alexia (letter-by-letter reading) selectively impaired for kana (Japanese phonograms), cerebral achromatopsia, and right lower quadrantanopsia after hemorrhage in the left posterior occipital lobe, mainly under the lateral occipital gyri. The patient also could not recognize some single-character kana, nor could he discriminate between two shapes of a similar size. The authors believe that the posterior occipital lobe, including the lateral occipital gyri, is specialized to recognize kana characters in this patient.

Lidocaine unmasks silent demyelinative lesions in multiple sclerosis.

Blockage of a small number of sodium channels may prevent impulse conduction in some demyelinated segments of nerve fibers with low safety factors, thereby unmasking subclinical demyelinative lesions. On the basis of this hypothesis, lidocaine, a sodium channel blocker, was administered intravenously to 28 MS patients and to 19 normal subjects and seven patients with nondemyelinating diseases. As predicted, lidocaine (mean plasma level, 2.7 micrograms/ml) elicited reversible subclinical symptoms in 23 of the MS patients, but it had not effect on the control subjects. We made a quantitative study of the visual functions (visual acuity, color vision, visual evoked potential [VEP]) that were impaired in 15 MS patients. Of the 23 affected eyes, nine showed normal VEPs, indicative of the test's sensitivity to focal lesions. This test should be useful in the diagnosis of MS and in the evaluation of the subclinical activity of MS as well.

Amyotrophic lateral sclerosis: histologic, histochemical, and ultrastructural abnormalities of skin.

We studied the reticular dermis in patients with amyotrophic lateral sclerosis (ALS) and controls with or without neurologic diseases. By light microscopy, collagen bundles in ALS dermis were reduced in amount and more loosely woven than in controls. Electronmicroscopy revealed a significant negative correlation between duration of illness and the diameter of collagen fibrils in patients with ALS. There was also a marked increase of amorphous material positive for ruthenium red in the ground substance. These findings were not observed in controls.

A multi-center, double-blind study on slow-release bromocriptine in the treatment of Parkinson's disease.

We report on the clinical efficacy of a slow-release formulation of bromocriptine studied in a multi-center, double-blind trial using standard bromocriptine as the control. We randomly allocated enrolled patients (N = 243) to either the slow-release or normal bromocriptine group. Sixty of them were de novo patients. The maintenance dose of slow-release bromocriptine was 14.2 +/- 0.7 mg/d and that of standard bromocriptine 13.5 +/- 0.7 mg/d (mean +/- SE). The slow-release formulation was taken twice and the standard three times a day. Forty-one percent of the patients treated with the slow-release bromocriptine and 32% of the patients treated with the standard bromocriptine showed moderate or marked improvement in the global improvement rating. There were no serious side effects, and the frequency of vomiting and epigastric discomfort was lower in the patients treated with the slow-release bromocriptine. Clinical efficacies for tremor, rigidity, akinesia, and gait disturbance were comparable between the two drugs tested. The slow-release bromocriptine seems to be a valuable drug for the treatment of Parkinson's disease with less severe side effects than regular bromocriptine.

Motor dominant neuropathy and IgM paraproteinemia: the IgM M-protein binds to specific gangliosides.

In a case of motor-dominant neuropathy and IgM paraproteinemia, the binding specificity of the serum IgM M-protein was characterized by enzyme-linked immunosorbent assay (ELISA). The serum IgM M-protein bound preferentially to ganglioside GM1 with slight cross-reactivity to both GM2 and GD1b. The binding specificity of the antibody and clinicopathological features are discussed.

The immunological homology between two filamentous cross-linker phosphoproteins, connectin and cross-bridge region of neurofilament-H, is not affected by the phosphorylation state.

It has recently been shown that a monoclonal antibody SM 1-36-2 against connectin, an elastic filament of striated muscles, binds to the "elastic" domain of the molecule, and that the H subunit of neurofilament (NF-H), an intermediate filament of nerve cells, shares a homologous domain (Shimizu, T. et al. (1988) Biomed. Res. 9, 227-234 and Itoh, Y. et al. (1988) J. Biochem. 104, 504-508). In order to characterize (1) the intramolecular localization of the domain in the NF-H and (2) the effect of the phosphorylation state on the immunoreactivity, the homologous domain in the NF-H was analyzed by Western blotting after limited digestion with trypsin or alpha-chymotrypsin and dephosphorylation with E. coli alkaline phosphatase. It was found that (1) the epitope was located not in the core region but in the carboxyl-terminal peripheral (cross-bridge) region of NF-H and (2) the epitopes in connectin and NF-H were not affected by the phosphorylation state.

Monitoring of the refolding process for immobilized firefly luciferase with a biosensor based on surface plasmon resonance.

In order to examine the possibility of the use of a surface plasmon resonance (SPR) sensor for real-time monitoring of the process of refolding of immobilized proteins, the refolding of firefly luciferase immobilized on a carboxymethyldextran matrix layer was analyzed. The SPR signal of the immobilized luciferase decreased after unfolding induced by GdnCl and increased gradually in the refolding buffer, while there was no signal change in the reference surface lacking the immobilized protein. The decrease in the SPR signal on unfolding was consistent with the difference between the refractive indices of the native and unfolded protein solutions. The effects of blocking of the excess NHS-groups of the matrix layer on the refolding yield were examined by means of an SPR sensor. The results were consistent with those obtained with the enzymatic activity assay, indicating that the changes in the SPR signal reflected the real-time conformational changes of the immobilized protein. Hence, an SPR biosensor might be used for monitoring of the process of refolding of immobilized proteins and as a novel tool for optimization of the refolding conditions. This is the first demonstration that SPR signal changes reflect the conformational changes of an immobilized protein upon unfolding and refolding.

Developmental changes of fucosylated glycoconjugates in rabbit dorsal root ganglia.

Developmental changes of the fucosylated glycoconjugates in the dorsal root ganglia (DRG) of the rabbit were investigated histochemically using anti-fucosyl GM1 antibody and Ulex europaeus agglutinin 1 (UEA-1) lectin. Neither anti-fucosyl GM1 antibody nor UEA-1 lectin bound to the neural tubes or to the neural crest on embryonic day 14 (E14). Anti-fucosyl GM1 antibody binds diffusely to the DRG of E25. Large neurons unreactive with anti-fucosyl GM1 antibody appeared at 1 month and increased within 6 months after birth. Schwann cells immunoreactive with anti-fucosyl GM1 antibody came to be limited to the satellite cells surrounding the positive neurons. No staining with UEA-1 lectin was observed in the DRG of E25. Some small neurons became reactive with UEA-1 lectin within 1 month and remained to be so at 6 months after birth. Schwann cells including satellite cells were unreactive with this lectin. Since fucosyl GM1 was detected in the lipid fraction of DRGs from 1-month-old and 6-month-old rabbits, fucosyl GM1 itself should be the antigen molecule recognized by the anti-fucosyl GM1 antibody. Further study is necessary to elucidate the association between these developmental changes of the fucosylated glycoconjugates in DRG and their possible functional roles.

Discrimination of human dorsal root ganglion cells by anti-fucosyl GM1 antibody.

Some neurons and surrounding satellite cells in human dorsal root ganglia were immunostained with rabbit IgM antibody against the ganglioside fucosyl GM1. They were not immunostained with the anti-GM1 antiserum. Immunohistochemical discrimination of neurons in human dorsal root ganglia by the anti-fucosyl GM1 antibody may give us an important clue to the functional identification of neurons conveying different modalities of sensation.

Localization of sulfated glucuronyl glycolipids in human dorsal root and sympathetic ganglia.

Sulfated glucuronyl glycolipids (SGGLs) in human dorsal root ganglion (DRG) and sympathetic ganglion (SG) were analyzed biochemically and immunohistochemically. SGGLs were enriched in human DRG (1.02 +/- 0.23 micrograms/mg protein), whereas much lower concentrations of these glycolipids (0.043 +/- 0.23 micrograms/mg protein) were detected in SG. Myelin within DRG and SG was immunostained by anti-SGGL antiserum, although only a few myelinated fibers were seen in SG. Nerve cell bodies or unmyelinated fibers were not immunostained. Subcellular fractionation study of human DRG demonstrated that these glycolipids were not only enriched in myelin but also in the axolemma-enriched fraction. These data are consistent with the view that SGGLs may be expressed on myelinated fibers in myelin and axolemma, suggesting that these compounds may play an important role in regulating myelinogenesis.

Rimmed vacuolar distal myopathy: a clinical, electrophysiological, histopathological and computed tomographic study of seven cases.

The following report describes the clinical, laboratory, electrophysiological, histopathological and computed tomographic studies of seven cases of distal myopathy with rimmed vacuoles in the muscle fibers. Each displayed several characteristic features. First, the onset was in early adulthood. Second, there was a unique distribution of muscle involvement: tibialis anterior and extensor digitorum and hallucis muscles were initially and most severely affected. The hamstrings and adductors of the thigh were also markedly involved. The gluteus medius and minimus muscles and the neck flexors were mildly affected in the relatively early stages. In contrast, the gastrocnemius, soleus, quadriceps femoris, and gluteus maximus muscles were well preserved until an advanced stage. Third, serum creatine kinase activity was normal or only mildly elevated; fourth, EMG were mainly myopathic, with certain neuropathic features; and fifth, histopathologically rimmed vacuoles in muscle fibers were found associated with certain "neuropathic" features, such as angular fibers, clustering of atrophic fibers, pyknotic nuclear clumps, and fiber-type predominance. The characteristic distribution of skeletal muscle involvement was particularly noticeable, together with certain "neuropathic" features of the EMG and muscle biopsy in rimmed vacuolar distal myopathy.

Rimmed vacuolar distal myopathy. An ultrastructural study.

An ultrastructural study of biopsied muscles was performed in seven patients with rimmed vacuolar distal myopathy, which was characterized by prominent rimmed vacuoles in the muscle fibers. The earliest changes noted were focal proliferation of the Golgi's apparatus and mitochondrial degeneration with myofibrillar loss. A proliferation of the T-system appeared later. Secondary lysosomes (autophagosomes) could be noted much later and gradually increased in number. Autophagosomes tended to coalesce and became larger autophagic vacuoles, which were surrounded in part by relatively preserved myofibrils and partly by a single membrane. Gently curved laminated structures (tubulomembranous structures) were seen in the degenerating muscle fibers and also in relatively intact fibers, satellite cells, and interstitial cells in all cases. They were closely associated with lipofuscin-like material. These findings suggest that an abnormality of the lysosomal system might be essential in the pathogenesis of rimmed vacuolar distal myopathy.

Myoclonus in Alzheimer's disease.

Myoclonus was studied electrophysiologically in seven patients with clinically diagnosed Alzheimer's disease. There seem to be at least two physiological types of myoclonus in Alzheimer's disease. Cerebral cortical structures might participate in the generation of myoclonus in one type, while the other type is probably generated by subcortical structures.

Fucosylated glycoconjugates in human dorsal root ganglion cells with unmyelinated axons.

The same subset of small neurons in human dorsal root ganglia (DRG) was recognized by both of the two probes binding to fucosylated residue. Ulex europaeus agglutinin I (UEA-1) lectin and anti-fucosyl GM1 antibody, although these probes bind to different glycoconjugates. UEA-1 lectin also bound to unmyelinated axons in DRG and in biopsied sural nerve, but not to any neurons or unmyelinated axons in the sympathetic ganglia. Thus UEA-1 lectin and anti-fucosyl GM1 antibody may be used as specific probes for primary sensory neurons with unmyelinated axons.

Myopathology of hypothyroid myopathy. Some new observations.

Eight muscle biopsies (3 from the left biceps, 3 from the left gastrocnemius, and 2 from the left quadriceps) of patients with hypothyroid myopathy were studied in the light of the previous literature. Some new observations have been made. First, the percentage of type II fibres is higher than that of type I fibres in all but 1 cases before treatment. Second, 5 of 8 cases before treatment disclosed 'core-like' structures, readily recognized with oxidative enzyme preparations in eccentric positions or in the periphery of type I fibres. They were reactive with myofibrillar adenosine triphosphatase (ATPase) activity and periodic acid-Schiff(PAS) staining, whereas with hematoxylineosin (HE) and modified Gomori trichrome the regions were more strongly reactive than the rest of the fibre. When examined by electron microscopy, within the 'core-like' structures of affected fibres, the A, I, and Z banding pattern was markedly disrupted. These structures disappeared after treatment with L-thyroxine. Third, none of the cases with Hoffmann's syndrome showed individual muscle fibre hypertrophy. Further study of these findings may yield information on clarifying the characteristics of muscle pathology of hypothyroid myopathy.

Differential diagnosis between amyotrophic lateral sclerosis and spinal muscular atrophy by skin involvement.

Amyotrophic lateral sclerosis (ALS) and spinal muscular atrophy (SMA) might be clinical variants caused by the same etiology, or different diseases altogether. We studied the skin in 12 patients with ALS and 7 patients with SMA. The "delayed return phenomenon" (DRP) was observed only in ALS patients. On light microscopy, collagen bundles in ALS dermis were seen to be less numerous, thinner and more loosely woven than in SMA. Electron microscopy revealed that in ALS (1) collagen fibers became thinner as the disease lasted longer, and (2) collagen bundles were separated by much more amorphous material. These findings were not observed in SMA. Our observations show that ALS may be distinguished from SMA by the presence of abnormal dermal collagen. Therefore, we suggest that comparable clinical and pathological skin analysis is the most important diagnostic tool in differentiating between ALS and SMA.

Increased dermal collagen density in amyotrophic lateral sclerosis.

We examined specimens of skin overlying the sacral region, among the most common sites of bedsores, from patients with amyotrophic lateral sclerosis (ALS) and controls, and found that in ALS patients, collagen fibrils had a greater density and became more tightly packed with the duration of illness. Our results suggest that the increased density of collagen fibrils may protect the skin of ALS patients from pressure ischemia, a major cause of bedsore formation.

"Ragged-red" fibres in myotonic dystrophy.

Twenty-five muscle biopsies (18 from the left biceps and 7 from the left quadriceps) of 25 patients suffering from myotonic dystrophy (MyD) were studied, 13 of which showed "ragged-red" fibres (RRFs); all the RRFs, which were type I fibres, were found in biceps muscles, while none of the quadriceps muscles showed RRFs. The incidence of RRFs varied from 0.5% to 20.0% (average 4.2%). On electron microscopy, RRFs contained enlarged mitochondria, usually in subsarcolemmal clusters, including dense granular matrix materials, concentrically whired membranous cristae, and paracrystalline inclusions, consistent with those of previously reported cases of mitochondrial myopathy, suggesting that RRFs observed in biopsies from patients with MyD are due to abnormal mitochondria. The biopsy findings indicative of MyD including pyknotic nuclear clumps, moth-eaten fibres, ring fibres, type I fibre atrophy, and type I fibre predominance, were much more common findings in biceps muscles than quadriceps muscles, and in biopsies with RRFs than those without RRFs. From our observations, it is possible that RRFs in biopsied muscles from patients with MyD are not incidental observations but are intimately associated with the pathogenesis of this disorder, and that RRFs may be a special form of pathological reaction in which accumulation of abnormal mitochondria occurs.

Immunochemical study of connectin (titin) in neuromuscular diseases using a monoclonal antibody: connectin is degraded extensively in Duchenne muscular dystrophy.

Connectin (also called titin) is a myofibrillar elastic filament which links a thick filament to a neighbouring Z line in a sarcomere and thus contributes significantly to the elastic property of myofibrils. In the present study, the degradation state of connectin in biopsied skeletal muscles from various neuromuscular diseases was investigated by Western blot analysis using a monoclonal antibody which reacts extensively with the degradation products of connectin. In Duchenne muscular dystrophy (DMD), connectin was degraded progressively and relentlessly after 5 years of age. In Becker muscular dystrophy, degradation of connectin was much less than in DMD. Connectin was well preserved in normal controls, and was only minimally degraded in Charcot-Marie-Tooth disease, amyotrophic lateral sclerosis, limb girdle muscular dystrophy and myotonic dystrophy, even when the biopsied muscles showed a similar degree of weakness as those of DMD. The degradation of connectin, even though secondary, is presumed to play an important role in the pathogenesis of myofibrillar degeneration in DMD.

Immunochemical analysis of alpha-actinin of nemaline myopathy after two-dimensional electrophoresis.

We analyzed alpha-actinin from human skeletal muscle by immunoblotting after two-dimensional electrophoresis. A monoclonal antibody, S alpha 5-17, was established after immunization in Balb/c mouse with crude alpha-actinin fraction from human soleus muscle. Western blotting and indirect immunofluorescence microscopy revealed that the antibody reacted selectively with alpha-actinin from human skeletal muscle and stained in a manner equivalent to that of type 1, 2A, 2B and 2C myofibers and cardiac atrial and ventricular muscles. No reactivity was observed in the arterial smooth muscle layer or in the central and peripheral nervous systems. The antibody exhibited 2 spots with different isoelectric points in a range more basic than that of actin upon immunoblotting after two-dimensional gel electrophoresis, suggesting the presence of 2 variants of alpha-actinin in human skeletal muscle. Analysis of type 2B-deficient muscle with nemaline myopathy or central core disease revealed that type 2B myofibers contained the basic variant, while type 1 and 2A myofibers contained only the acidic variant. Immunoblots performed after two-dimensional gel electrophoresis of muscles with nemaline myopathy revealed alpha-actinin variants indistinguishable from those of control muscles.