The motor end-plate fine structure and distribution of junctional acetylcholine receptors (AChRs) in patients with amyotrophic lateral sclerosis (ALS) were studied. Morphometric analysis was carried out in 74 end-plates (92 innervated and 47 denuded postsynaptic regions) from 10 patients with ALS. AChR was studied by means of peroxidase-labeled alpha-bungarotoxin binding in 45 end-plates (86 innervated and 36 denuded postsynaptic regions) from 6 patients with ALS. The postsynaptic regions were denuded of their nerve terminals in 33.8% (9.8% in controls). However, the postsynaptic folds in denuded regions were fairly well preserved, as were junctional AChRs. No highly simplified postsynaptic regions were observed. These results suggest that reinnervation of the skeletal muscle by nerve sprouting in ALS may occur in the previously denuded postsynaptic regions and the preserved postsynaptic regions including AChRs, the basement membrane, and Schwann cells may play an important role in this process.

Adult↗

PubMedDate not supplied

Renal cell carcinoma: preoperative assessment for enucleative surgery with angiography, CT, and MRI.

PURPOSE: Our purpose was to assess various imaging methods in detecting a pseudocapsule of renal cell carcinoma (RCC), which is critical for successful tumor enucleation. METHOD: In 42 patients with histopathologically proven RCC, images obtained at angiography (n = 42), CT (n = 30), and MRI (n = 19) were investigated retrospectively. All patients underwent treatment (enucleation: n = 15; nephrectomy: n = 27). The imaging criteria for the presence of a pseudocapsule were as follows: a surrounding radiolucent rim on angiography, a low or high density rim on CT, and a low intensity rim on MRI. All images were retrospectively reviewed by three radiologists without knowledge of the clinical and histological findings. RESULTS: Thirty-three of 42 RCCs showed a pseudocapsule on the surgical specimen. A pseudocapsule was detected in 67% of tumors (22/33) on angiography, 26% (6/23) on CT, 27% (4/15) on T1-weighted MRI, 93% (14/15) on T2-weighted MRI, 67% (8/12) on dynamic enhanced T1-weighted MRI, and 15% (2/13) on delayed enhanced T1-weighted MRI. CONCLUSION: T2-weighted MR images are superior for visualizing a pseudocapsule of RCC and for providing reliable selection criteria for tumor enucleation.

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PubMedDate not supplied

Experimental autoimmune myasthenia gravis: a sequential and quantitative study of the neuromuscular junction ultrastructure and electrophysiologic correlations.

Neuromuscular junction ultrastructure in rat forelimb digit extensor muscle was sequentially and quantitatively investigated in experimental autoimmune myasthenia gravis (EAMG). Experimental animals were immunized with highly purified eel electroplax acetylcholine receptor protein plus complete Freund's adjuvant and B pertussis vaccine; control animals received only adjuvant and vaccine. During the first 7 days (latent period) after immunization end-plate structure and neuromuscular transmission remained normal in the experimental group. Between day 7 and 11 (acute phase) mononuclear cells infiltrated those regions of muscle where the end-plates were located and there was intense degeneration of the postsynaptic regions with splitting away of abnormal junctional folds from the underlying muscle fibers. Macrophages entered the gaps thus formed and removed the degenerating folds by phagocytosis. The nerve terminals were displaced from their usual location but maintained their structural integrity. Neuromuscular transmission was blocked in many muscle fibers. Miniature end-plate potentias (MEPPs), detectable in only a few fibers, were of abnormally low amplitude. After day 11 (chronic phase) the nerve terminals returned to the highly simplified postsynaptic folds became reconstituted and again degenerated. Immature junctions with poorly differentiated postsynaptic regions and nerve sprouts near end-plates were also observed. In two animals relapsing during the chronic phase degeneration of the postsynaptic folds was more intense than in the other chronic-phase animals. The posysynaptic membrane length and length per unit area and the MEPP amplitudes were significantly decreased in all chronic phase animals and the decreases were greater in the relapsing than in the non-lapsing animals. Minor morphometric alterations were also observed in the nerve terminals. These might have been secondary to the postsynaptic changes. The postsynaptic region is the primary target of the autoimmune reaction in EAMG. The ultrastructural, morphometric and electrophysiological abnormalities of the end-plate in chronic EAMG resemble those which have been observed in human myasthenia gravis.

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PubMedDate not supplied

Human T-lymphotropic virus type I(HTLV-I) associated myelopathy in Nagasaki: clinical features and treatment of 21 cases.

The clinical features of 21 patients (7 men and 14 women, aged 24-65) with human T-lymphotropic virus type I (HTLV-I) associated myelopathy (HAM) in Nagasaki were reviewed. Gait disturbance with spastic paraplegia and bladder dysfunction were the main clinical symptoms. Gait disturbance was observed in all patients and bladder dysfunction was found in 20/21 (95.2%). Mild sensory disturbance was observed in 11/21 (52.3%) patients. Only 4 patients had received blood transfusions before the onset of illness. On the other hand, 6 patients who had family histories of HAM or spastic paraplegia were included as familial clusters of HAM. The study on the T-cell subpopulations revealed a significant increase in the percentage of OKT11+ cells, OKT3+ cells, OKT4+ cells, OKT8+ cells, OKIa1+ cells and IL-2R+ cells. We treated these 21 patients with plasma exchange (PE) and/or prednisolone in an uncontrolled manner. Both treatments were effective (PE: 11/18, prednisolone: 14/20), though the effects were not sufficient. In 5 patients, PE produced rapid and dramatic improvement. Anti-HTLV-I antibodies in serum and cerebrospinal fluid were not correlated with the efficacy of both treatments.

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PubMedDate not supplied

The efficacy of interferon-alpha treatment in human T-lymphotropic virus type-I-associated myelopathy.

We investigated the efficacy of interferon-alpha (IFN-alpha) treatment in 5 patients with human T-lymphotropic virus type I (HTLV-I)-associated myelopathy (HAM). Treatment with IFN-alpha yielded clinical improvement of gait, and sensory and/or sphincter disturbance in 4 out of the 5 HAM patients. IFN-alpha treatment did not bring about uniform changes in lymphocyte subsets or anti-HTLV-I antibody titer of peripheral blood. Although the stimulation indexes to phytohemagglutinin, concanavalin A, and pokeweed mitogen were decreased in the culture of the peripheral blood lymphocytes (PBL) in the 5 HAM patients before the treatment, the stimulation indexes to these mitogens were significantly increased except in 1 case after the IFN-alpha treatment. These changes were based primarily on the depression of the spontaneous proliferation of PBL without mitogen. These results appear to point out a very important phenomenon for the investigation of the pathogenesis of HAM.

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PubMedDate not supplied

Magnetic resonance imaging in diagnosis and follow-up of minimal thyroid ophthalmopathy.

We report a case of minimal thyroid ophthalmopathy treated with intravenous methylprednisolone, in which precise identification of the involved muscle was possible with the use of surface coil magnetic resonance (MR) imaging. Intravenous methylprednisolone was more effective than the oral prednisolone as judged by orbital MR imaging. MR imaging is one of the useful tools in the diagnosis and assessment of treatment in this field.

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