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Biomedical subjects

J Bethlem

Publications and source records attributed to J Bethlem.

At least 19 recordsLinked to original sources
PubMed1979

X-linked recessive congenital muscle fiber hypotrophy with central nuclei: abnormalities of growth and adenylate cyclase in muscle tissue cultures.

Muscle cells in cultures established from biopsy specimens of two children with an infantile-fatal form of X-linked recessive muscle fiber smallness with central nuclei showed an unusual ability to proliferate through numerous passages. Ultrastructurally, the cultured muscle fibers appeared very immature even after several weeks. The nuclei were large, the number of ribosomes was greatly increased, the myofibrils remained unstriated, and glycogen was accumulated in large lakes. The plasmalemma bound concanavalin A, alpha-bungarotoxin, and ruthenium red normally, but with tannic acid it did not show the dark binding of mature fibers. Biochemically, in the cultured muscle fibers, beta-adrenergic receptors were quantitatively normal. The level of adenylate cyclase in membranes was less than in cultured normal muscle; this defect could be responsible for impaired control mechanisms resulting in the other abnormalities observed.

Adenylyl Cyclases↗
PubMed1978

Leptomeres in cultured human muscle.

Leptomeres, the laminated structures consisting of bundles of very fine filaments separated into bands about 260 nm wide by periodic transverse dense lines 20--80 nm wide, were observed frequently in cultured muscle fibers of 8 patients with acid maltase deficiency, 4 with sporadic, adult-onset idiopathic "autophagic" vacuolar myopathy (that is not acid-maltase deficient) and one with abnormal mitochondria, but in only one of greater than 50 other cultures of normal and denervated human muscle. They were also induced abundantly in cultured normal human muscle by exposure to 0.5 mM DNP.

Culture Techniques↗
PubMed1978

Further investigations on benign myopathy with autosomal dominant inheritance.

Six members of a family suffered from benign myopathy over four generations. The clinical, laboratory, electromyographic, histological and genetic data were consistent with benign myopathy with autosomal dominant inheritance. Congenital torticollis was a feature in one patient. Linkage studies revealed no linkage between the locus of this myopathy and the locus of any of 17 genetic markers investigated. This family was of Polish descent, which indicates a widespread occurrence of this benign hereditary myopathy. The data presented are a strong argument in favor of a specific new disease entity.

Adipose Tissue↗
PubMed1978

Investigations on the inheritance of nemaline myopathy.

Extensive investigations on 11 patients with nemaline myopathy (six index patients, five relatives), their parents, and some healthy relatives were carried out. In one family, nemaline myopathy was inherited as an autosomal dominant trait. No linkage between the locus of nemaline myopathy and the locus of seven informative genetic markers (out of 25 investigated markers) was found. In two families an autosomal recessive inheritance could be demonstrated with certainty. In these families, both parents of each index patient had rods and an increased number of fibers with internal nuclei. In two other families, one or both parents of each index patient had an increased number of fibers with internal nuclei, also indicating the possibility of autosomal recessive inheritance in these cases. It can be concluded that there are two types of nemaline myopathy. However, these two diseases could not be separated on a clinical or histopathological basis.

Adolescent↗
PubMed1978

Common origin of rods, cores, miniature cores, and focal loss of cross-striations.

Twelve patients suffering from congenital neuromuscular disorders showed at least two of the following structural changes in their muscle biopsy specimens: rods, cores, miniature cores (M lesions), and focal loss of cross-strians (F lesions). There appeared to be no essential differences between M and F lesions except for the presence of vesicular nuclei in and around the latter. A striking finding was the presence of adjacent M lesions, F lesions, or both in two or several adjoining muscle fibers. Serial sections often showed a definite relationship of the lesions with blood vessels. The finding of rods cores, and M and F lesions, not only in one biopsy specimen but also in one muscle fiber, raised the intriguing possibility of common pathogenic mechanisms producing these lesions.

Adult↗
PubMed1977

Familial focal loss of cross striations.

Two patients, a brother and sister, both suffering from congenital generalized muscle weakness with a progressive course are reported. Muscle biopsy revealed areas with loss of cross striations in the muscle fibers, electronmicroscopically presenting complete disorganization of the myofibrils with streaming of the Z discs and absence of mitochondria. Vesicular nuclei with prominent nucleoli were present in these areas. There was a type I fiber predominance in both cases. The mean diameter of the type I muscle fibers in one of the cases was too small. Motor endplate alterations in this patient gave no evidence of denervation but were suggestive of a delayed development of motor nerves.

Adolescent↗
PubMed1976

Benign myopathy, with autosomal dominant inheritance. A report on three pedigrees.

Three pedigrees are described in which 28 living siblings suffered from a benign myopathy. The first symptoms were observed around the fifth year of life. The proximal muscles were more involved than the distal muscles, the extensors more than the flexors. Due to a marked paresis of the extensor digitorum communis muscles 22 patients showed a flexion contracture of the interphalangeal joints of the last four fingers. In addition 20 patients showed a flexion contracture of the elbows and 12 patients had a plantar flexion contracture of the ankles. A high incidence of congenital torticollis was found. The histopathological features were non-specific and remarkably uniform and consisted of a marked variation in muslce fibre diameter and a very marked increase of fatty tissue. Light-microscopy and electronmicroscopy did not show any specific structural changes. There was normal distribution of type I and type II fibres, without type-grouping or preferential atrophy of one of the fibre types. Lobulated type I fibres were found in 6 out of 12 biopsies. Post-mortem study of one case did not show any convincing features of a neurogenic disorder. As no relationship could be found between the siblings of the 3 pedigrees as far back as the beginning of the eighteenth century, this myopathy seemed to be a new nosological entity.

Adolescent↗
PubMed1976

Changes in motor innervation and histochemical pattern of muscle fibers in some congenital myopathies.

Changes in motor innervation were compared with histologic and histochemical pattern of muscle fibers in three biopsies of central core disease, four biopsies of nemaline myopathy, one biopsy of myotubular myopathy, and three biopsies of mitochondrial myopathy. Evidence of collateral reinnervation was obtained only in one biopsy from central core disease. In other biopsies, no structural or ultrastructural abnormality of axis cylinders, myelin, or myoneural junction suggesting denervation were observed. The only relevant change found in centronuclear myopathy and to a lesser extent in nemaline myopathy was an unusual smallness and simplication of motor endings, suggesting delayed or impaired maturation. Muscle fibers strongly reactive for both adenosinetriphosphatase and nicotinamide-adenine dinucleotide diaphorase, observed in central core disease and mitochondrial myopathy, were not associated with increased terminal innervation ratio.

Adolescent↗
PubMed1975

X-linked myotubular myopathy with fatal neonatal asphyxia.

A second family with X-linked myotubular myopathy is described. The clinical picture includes decreased fetal movements; hydramnios, in at least three cases, probably resulting from insufficient swallowing in utero; and asphyxia at birth. In three autopsy cases many myotubes were found in the muscle tissue. In five definite female carriers, muscle biopsy revealed changes, including myotubes in four. This family probably is not related to the eariler described family with X-linked myotubular myopathy, from which it differs in its 100 percent fatal outcome in the neonatal period, as compared with 25 percent in the eariler described family. A most important finding, in both families, is the possibility of recognizing clinically healthy female carriers by muscle biopsy.

Asphyxia↗
PubMed1973

Neurogenic muscle involvement in myasthenia gravis. A clinical and histopathological study.

An investigation was made into the occurrence of muscular atrophy and muscular pathology in a series of 170 patients with myasthenia gravis. The results can be summarized as follows: (1) Of the 148 patients with generalized myasthenia gravis, 14 showed local muscular atrophies. Of 10 biopsies from atrophic muscles, eight showed neurogenic changes, with or without lymphocytic infiltrations. One biopsy showed lymphocytic infiltrations only, and one showed type II-fibre atrophy (Table 1). No relationship was demonstrable between the presence of clilnical muscular atrophy and age, sex, duration of the disease, severity of the disease, presence of a thymoma, or drug resistant ophthalmoplegia. (2) In this group of patients 61 biopsies were examined from 46 individuals; 40 of these biopsies were taken from the quadriceps muscle. A thymoma was present in 17 patients. Examination disclosed neurogenic changes in 17 biopsies, lymphocytic infiltrates in 21, and myositis in one biopsy (Table 2). A distinct correlation was established between the presence of a thymoma and lymphocytic infiltrates, but none was demonstrable between thymoma and neurogenic changes (Table 3). (3) An enzyme-histochemical study was carried out in 35 cases, including 12 with neurogenic changes. A normal differentiation of type I- and type II-fibres was observed in eight instances, type grouping of type II-fibres in three, and type II-fibre atrophy in two cases. (4) In 21 patients and 19 controls, the smallest mean diameter was determined in the quadriceps muscle. Both type I- and type II-fibres proved to have a smaller mean diameter in the female patients than in the controls. In the male patients this could not be proven. (5) Of the eight patients who had died without disorders of ventilation, 90 muscle specimens were examined postmortem. Four of these patients had a thymoma. Lymphocytic infiltrations, found in 32 biopsy specimens, were mostly observed in the presence of a thymoma. Neurogenic changes were apparently unrelated to the presence of a thymoma (Tables 5 and 6). The post mortem examination included the spinal cord in five, and peripheral nerves in three cases. No abnormalities were found. (6) The muscular atrophy found in patients with myasthenia is not a myopathy but an affection of the lower motor neurone. Neurogenic changes were regularly found in the muscles of patients with myasthenia, even without muscular atrophy. The finding of these changes is no reason to reject the diagnosis. It is postulated that denervation occurs at the neuromuscular junction as a result of permanent absence of acetylcholine.

Adolescent↗