N.B. Bahuth

Augmentation of nociceptive reflexes and chronic deafferentation pain by chemical lesions of either dopaminergic terminals or midbrain dopaminergic neurons

Neurodegenerative diseases affecting the midbrain dopaminergic system have been reported to produce spontaneous pains like in Parkinsons disease. Using various pain tests for acute (hot plate test, HPT, tail flick, TFT, paw pressure test, PPT and paw immersion test, PIT) and chronic deafferentation (autotomy, AT, following peripheral neurectomy) pains in rats, we have investigated the effects on these tests of selective chemical lesions with 6-hydroxydopamine (6-OHDA) or/and kainic acid (KA) either in the striatum or in the substantia nigra (SN) and ventral tegmental area (VTA). 6-OHDA lesions of dopaminergic terminals in the striatum decreased significantly the latencies of all nociceptive reflexes (HPT from 11.7 +/- 1.45 s to 7 +/- 1.35 s, TFT from 4.5 +/- 0.15 s to 3.2 +/- 0.16 s and PPT on the contralateral leg from 2.07 +/- 0.45 s to 1.05 +/- 0.085 s) and accelerated the time of onset (from 10.82 +/- 2.3 days to 3.1 +/- 0.52 days) and end (from 29.5 +/- 5.6 days to 5.2 +/- 1.1 days) of AT. These effects were not modified by simultaneous injection of KA and 6-OHDA in the striatum. 6-OHDA lesions in the SN-VTA produced comparable effects to those of similar injections in the striatum, while KA lesions in the SN-VTA did not produce significant changes in the latencies of nociceptive reflexes or in the AT criteria. These results suggest that the dopaminergic system plays a major role in the processing of nociceptive information in the striatum and the limbic areas.

Clofibrate-induced muscular syndrome. Report of a case with clinical, electromyographic and pathologic observations.

In this report the clinical features of a case of clofibrate-induced muscular syndrome, as well as the electromyographic, histochemical, light- and electron-microscopic findings are described. The clinical features are similar to those of previously reported cases. Electromyography was consistent with a myopathy. Histochemical profile was normal. The myopathology included breakdown of contractile material, deranged mitochondria, dilated sarcoplasmic reticulum profiles, accumulation of membrane bound dense bodies, discontinuities in sarcolemma and thickening of capillary basement membrane. Macrophages invaded severely affected fibers.

Correlative Study of the Physiologic and Morphologic Characteristics of the Temporal and Masseter Muscles of the Cat

The electrophysiologic and morphologic features of cat temporal and masseter muscles were investigated. The temporal muscle possessed a majority of type A fibers; type B and C were dominant in the masseter muscle. The temporal muscle demonstrated slower contraction speed, wider twitch duration, and earlier tetanus fusion than the masseter muscle.

Concentrically laminated membranous inclusions in myofibres of Dyggve-Melchior-Clausen syndrome

Abstract Concentrically-laminated membranous inclusions reported only once previously, are described in muscle from a patient with the Dyggve-Melchior-Clausen syndrome. They exhibit a banding pattern and are characteristically located in subsarcolemmal sites. They may represent a non-specific myopathological reaction.

Partial (localized) lipodystrophy: Report of a case with muscle and skin abnormalities

The light and electron microscopic myopathologic and dermatopathologic features in one patient with the partial (localized) type of lipodystrophy are described. The myopathologic changes involve both the contractile elements and the intracellular organelles, especially mitochondria that show hyperplasia and structural alterations of cristae. The dermatopathologic changes consist of a reduction in subcutaneous fat, intercellular edema, and the presence of intracytoplasmic lipid droplets. This is the first report in the literature in which the myopathologic features and detailed electron microscopy of skin in this condition are described. The myopathologic features of partial lipodystrophy are compared with those of congenital generalized lipodystrophy. It is proposed that a myopathy may be one of the manifestations of partial lipodystrophy.

Clofibrate-Induced Myotoxicity in Rats

In this report, the temporal sequence of myopathology during a clofibrate-induced muscular syndrome and its recovery in rats is described using histopathologic, histochemical and electron microscopic technics. Two stages of myopathology are described: an early stage characterized by myopathic features, and a later stage characterized by neurogenic features. Although muscle histology returns to normal after 1 week of discontinuing the drug, electron microscopic abnormalities persist through the second week. It is proposed that clofibrate, in addition to its myotoxic effect, may be neurotoxic.

Neurogenic muscular atrophy in Behcet's disease

SummaryA child is reported with Behcets disease who presented with skin and joint manifestations, oral ulcers, brainstem syndrome and neurogenic muscular atrophy. The neurogenic muscular atrophy was confirmed by electrophysiologic, histologic and histochemical studies. Electron microscopy of muscle showed a vasculopathy. The possible etiology of the muscle lesions is discussed. The relevant literature on muscle and peripheral nerve involvement in Behcets disease is reviewed. It is proposed that neuromyopathy be added to the neurological manifestations of Behcets disease. To our knowledge, this is the first case of neurogenic atrophy reported in Behcets disease.

The myopathology of Behçet's disease: A histochemical, light-, and electron-microscopic study

The myopathology of Behçets disease is described in 7 patients using conventional light microscopy, histochemistry, high-resolution light microscopy and electron microscopy. Two patients had clinical evidence of peripheral neuropathy: 5 patients had no clinical evidence of neuromuscular involvement. Histochemical profile of muscle in all patients was normal. Abnormalities in muscle histology using conventional light microscopy were found in only 1 patient. High-resolution light microscopy revealed abnormalities in 3 patients whereas electron microscopy revealed abnormalities in muscle of all 7 patients. The myopathology of Behçets disease includes thickening of capillary basement membrane, excessive pleating of sarcolemma, subsarcolemmal aggregates of mitochondria and glycogen, disorganization and breakdown of myofibrils, central nucleation and the presence of a variety of cytoplasmic inclusions. No virus particles were present.

Postganglionic Cholinergic Dysautonomia; Report of Muscle Findings in 1 Case

Heretofore unreported findings in skeletal muscle in a 4th case of pure postganglionic dysautonomia are described. They consist of variation in fiber size, Z line and myofilamentous disorganization, intracytoplasmic inclusions and honeycomb formations. The most striking alterations, however, was excess lipid accumulation without concomitant mitochondrial alterations. Sural nerve histology and cytology were normal. The mechanism of lipid accumulation in skeletal muscle of patients with dysautonomia remains unexplained.