Pathophysiology on the disorder of neuromuscular transmission defects

Neuromuscular transmission defects are often puzzling but challenging diseases for the pediatric and adult neurologists. Some of these disorders entail severe or even life-threatening disability: Most are treatable, but effective therapy requires precise diagnosis sometimes difficult to make especially in congenital defects. The diagnosis rests on the combination of clinical data, the electromyogram and additional studies that may include microelectrode analysis of neuromuscular transmission, ultrastructural and cytochemical studies of neuromuscular junction (NMJ) and biochemical/molecular genetic studies on muscle specimens. Understandably, these studies often depend on the collaboration of several investigators. In each myasthenic disorder, an abnormality affects neuromuscular transmission directly or causes secondary derangements that eventually affects transmission. Namely, lesions of both the presynaptic and/or postsynaptic area manifest a variety of clinical findings. Here was discussed the pathophysiology on myasthenia gravis and Lambert-Eaton myasthenic syndrome of abnormal autoimmunity, congenital myasthenic syndromes of a chromosomal defect, and poisoning of organophosphorus, botulism and some other toxins.     

The surgical treatment of hepatic echinococcosis and of its biliary complications

The authors report the experience of 47 patients submitted to surgery for hepatic hydatidosis. Results from different therapeutic procedures are then compared. Finally, possible biliary complications of the hepatic echinococcosis and their surgical treatment are discussed.     

Lattice corneal dystrophy type II associated with familial amyloid polyneuropathy type IV

BACKGROUND: Finnish-type familial amyloidosis (FAP-IV) is an autosomal, dominantly inherited disorder characterized by progressive polyneuropathy and lattice corneal dystrophy type II. The vast majority of families with this disorder originated from Finland. Only two families, in neighboring districts, have been reported in Japan previously. METHODS: The authors report two additional Japanese patients with FAF-IV. The proband, a 70-year-old man, had decreased perspiration and abnormal facial muscle movement. Results of neurologic examination showed bilateral facial and hypoglossal nerve palsies, and an autonomic disturbance, including orthostatic hypotension and dysfunction of perspiration. Histochemical, immunohistological, and DNA studies confirmed the diagnosis of FAP-IV. RESULTS: Results of ophthalmologic examination showed asymptomatic lattice corneal dystrophy of both eyes, but the appearance of the cornea was different from that described in the patients from Finland. Lattice lines in the authors' patient were very fine, short, and glassy and could be observed with indirect retroillumination, but might be missed with direct illumination by the slit-lamp microscope. The proband's younger half-sister, a 68-year-old woman, showed clinical findings and laboratory data similar to those of the proband. CONCLUSION: The authors report two Japanese patients with lattice corneal dystrophy type II related to FAP-IV. This is the third Japanese family with this disorder, and there is no familial relationship to the two previously reported families in Japan.     

Immunohistochemical localization of chymase; a mast cell marker and clinical significance in diseased human skeletal muscle

In the advanced stage of dystrophinopathy, cardiac dysfunction is a serious complication for prognosis. Recently, an angiotensin converting enzyme (ACE), which converts angiotensin (A) 1 to A 2, has been reported to be effective for cardiac insufficiency. The A 2 is produced more dominantly in the path via the production of a neutral serine protease, chymase (MW 25,000), secreted from the mast cell. We have observed localization of chymase in diseased human skeletal muscle tissues, and evaluated its clinical significance. The frozen muscle biopsied specimens from 91 neuromuscular disorders (muscular dystrophies, inflammatory myopathies and neurogenic muscular disorders) were stained by using monoclonal antibody against the chymase, and the positive cells in a whole sectional field were counted. In the serial sections, we also performed routine histochemistry and immunostainings of immunological markers (CD4, CD8 and others) as well as the apoptotic proteins for comparison. RESULTS: The chymase-positive mast cells were scattered mainly in the endomysium, partly in the perimysium and around small vessels. Although the positivity was not disease specific, more numerous strongly positive cells were observed in dystrophinopathy and inflammatory myopathies, but less in myotonic dystrophy and neurogenic muscle disorders. In the normal control muscle, however, strongly positive cells appeared less frequently than in the above mentioned diseased muscles. The chymase-positive cells partly corresponded to the ubiquitin-positive ones, but perforin, granzyme A, Fas and Bcl-2 did not. In conclusion, the chymase-positive mast cell may play a primary or secondary role in the diseased muscle, and their more abundant appearance in dystrophinopathy and some other myopathies suggest the effectiveness of an ACE blocker, an anti-chymase drug.     

Transmission electron microscopy study of GdBa2Cu3O7−x containing nano-sized BaMO3 (M: Hf, Zr, Sn) rods fabricated by pulsed laser deposition

Three types of superconducting GdBa₂Cu₃O_7?x (GdBCO) layers containing rods of either BaHfO₃ (BHO), BaZrO₃ (BZO), or BaSnO₃ (BSO) were fabricated by pulsed laser deposition on Hastelloy substrates with a CeO₂ based textured buffer layer. The critical currents (J _c) values of the GdBCO layers containing those nano-rods are enhanced compared with those of pristine GdBCO layer in high magnetic fields. In order to investigate the relationships between their superconductive properties and their nanostructures, they were characterized in detail by transmission electron microscopy (TEM). TEM is the only method for direct observation of these nano-rods in the GdBCO grains. The GdBCO layers were mainly composed of c-axis oriented GdBCO grains containing numerous nano-sized rods. The crystal orientation relationships between the GdBCO and the nano-rods were as follows; (001)GdBCO//(001)nano-rods and (100)GdBCO//(100) nano-rods. The average diameters of the BHO and the BZO nano-rods were 4.5 and 5.6 nm, respectively. The BSO nano-rods were thicker than other rods. These nano-rods in the central region of the c-axis oriented GdBCO grains were aligned parallel to the c-axis of the GdBCO, while nano-rods in the outer region of the c-axis oriented grains were tilted away from the c-axis. With increase in the thickness of the GdBCO layers, the ratio of the BZO or the BSO nano-rods aligned parallel to the c-axis to those tilted away from the c-axis decreased, so that the J _c-B-θ profiles of the thicker GdBCO layers containing the BZO or the BSO nano-rods became flatter. The BHO nano-rods were homogeneously distributed throughout the GdBCO, and their average length of was less than that of the other nano-rods. The homogeneous distribution and short length of the BHO nano-rods enhanced the J _c values of the GdBCO layers containing them in high magnetic fields. The J _c-B-θ profiles of the GdBCO layers containing the BHO were independent of the layer thickness. From these results, we will discuss about the morphologies and distributions of suitable vortex pinning for applications of GdBCO coated conductor in high magnetic fields.     

Prediction of slippage onset condition between web and steel roller

This paper describes the theoretical modeling for the prediction of slippage onset condition between the paper web and steel roller with experimental verifications. For the first step of modeling, the occurrence of slippage is observed for the cases of uncoated paper (newsprint) and coated paper, and the relation between the slip ratio and roller velocity is measured by changing web tension. Two kinds of theoretical model are proposed, and the applicability of the models is confirmed experimentally.     

Enhancing the Fischer–Tropsch Synthesis Activity of Co-based Catalysts by Adding ZrOx to the SiO2 Support and Chelating Ligands to the Co-precursor

Abstract  

Co/ZrO _x /SiO₂ catalysts with enhanced dispersion of Co⁰ and turnover frequency were successfully prepared combining two different promotion effects, i.e., modifications of SiO₂ surface with ZrO _x by liquid phase deposition and influencing coordination structure of Co species using chelating agents or glycols. The catalysts exhibited ~6.3-fold higher CO conversion than Co/SiO₂ and those promoted by organic additives or ZrO _x alone, indicating activity enhancement was induced by cooperation of these two promoters.     

Multi-scale,multi-depth lithography using optical fibers for microfluidic applications

This paper proposes and demonstrates a method for multi-scale, multi-depth three-dimensional (3D) lithography. In this method, 3D molds for replicating microchannels are fabricated by passing a non-focused laser beam through an optical fiber, whose tip is immersed in a droplet of photopolymer. Line width is adjustable from 1 to 980 µm using eight kinds of optical fibers with different core diameters. The height of line drawing can be controlled by adjusting the distance between the tip of the optical fiber and a substrate. The surface roughness (R_a, R_z) of a single line and plane was evaluated. The method was employed to fabricate a 3D mold of a microchannel containing tandem chambers, which was then successfully replicated in PDMS. Multi-scale, multi-depth 3D lithography can provide a simple, flexible tool for producing PDMS microfluidic devices.     

Mechanism of selective motor neuronal death after exposure of spinal cord to glutamate: involvement of glutamate-induced nitric oxide in motor neuron toxicity and nonmotor neuron protection

In this study, we analyzed the mechanism of selective motor neuronal death, a characteristic of amyotrophic lateral sclerosis, using embryonic rat spinal cord culture. When dissociated cultures were exposed to low-level glutamate (Glu) coadministered with the Glu transporter inhibitor L-trans-pyrrolidine-2,4-decarboxylate (PDC) for 24 hours, motor neurons were selectively injured through N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA)/kainate receptors. Nitric oxide synthase (NOS) inhibitors attenuated this toxicity, and long-acting nitric oxide (NO) donors damaged motor neurons selectively. Nonmotor neurons survived after exposure to low-dose Glu/PDC, but Glu-induced toxicity was potentiated by coadministration of an NO-dependent guanylyl cyclase inhibitor. In addition, 8-bromo-cyclic GMP, a soluble cyclic GMP analogue, rescued nonmotor neurons, but not motor neurons, exposed to high-dose Glu/PDC. Twenty-four hours' incubation with PDC elevated the number of neuronal NOS-immunoreactive neurons by about twofold compared with controls, and a double-staining study, using the motor neuron marker SMI32, revealed that most of them were nonmotor neurons. These findings suggest that selective motor neuronal death caused by chronic low-level exposure to Glu is mediated by the formation of NO in nonmotor neurons, which inversely protects nonmotor neurons through the guanylyl cyclase-cyclic GMP cascade. Induction of neuronal NOS in nonmotor neurons might enhance both the toxicity of motor neurons and the protection of nonmotor neurons, which could explain the pathology of amyotrophic lateral sclerosis.