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Biomedical subjects

B Ryniewicz

Publications and source records attributed to B Ryniewicz.

At least 37 records · Page 2Linked to original sources

Is central core disease with structural core a fetal defect?

Morphological and biochemical studies were performed in three cases of congenital non-progressive myopathy in two generations of the same family. In the muscle biopsy nearly all the fibres were uniform in enzyme activity and belonged to type 2 C. Typical structural central cores were observed in 90% of the muscle fibres. Some ultrastructural characteristics of the core area, as well as disturbances of the myofibrillar proteins pattern, seen in the examined cases suggest that core formation may be a result of protein synthesis disturbances in an early stage of myogenesis.

Adult↗

Preliminary immunological studies in spinal muscular atrophy.

Evidence of impaired cell-mediated immunity in children with spinal muscular atrophy was obtained using lymphocyte transformation with PHA (20 children) and skin tests with tuberculin and DNCB (35 children). Laryngological examination of 16 children demonstrated hypoplasia of lymphatic tissue in Waldeyer's ring and the cervical lymph nodes. An ectodermal defect involving both spinal cord and thymus is suggested.

Adolescent↗

Follow-up study of myasthenic children after thymectomy.

The results of thymectomy of 28 myasthenic children observed from 1 to 9 years after operation are discussed. Improvement was obtained in 19 cases (67.8%), with full remission in 12 cases (42.8%). Six children died. No correlation was found between the results of thymectomy and the duration of the disease, sex or histological findings in the thymus. No increase of incidence or severity of infections were observed in thymectomized children. Caution is recommended regarding vaccination of myasthenic children.

Adolescent↗

Electromyographic findings in the so-called non-progressive myopathies.

Electrophysiological findings in 40 cases of non-progressive myopathies are reported, and compared with a group of 20 cases of Duchenne progressive muscular dystrophy and a control group. In all cases the electrophysiological changes were of the mild s. c. myogenic type. The involvement of proximal and distal muscles was equal without prevalence in proximal muscles as is typical for Duchenne's dystrophy. EMG reexaminations showed a slight progression of the diseases. A peculiar feature of myotubular myopathy was spontaneous activity (fibrillation) in 70% of muscles. A myogenic character of the process of congenital deficiency of muscle innervation with preserved number of motor units is suggested.

Action Potentials↗

[Is there true remission in myasthenia gravis? Long-term clinical and electrophysiological studies].

Twenty myasthenic patients were followed up who had in the years 1981-1982 full clinical remission (no drugs, no symptoms), lasting at that time at least several years. However, in 19 of them neuromuscular transmission defects were then found by single fibre electromyography (SFEMG). We then concluded that true remissions did not exist in myasthenia (J. Neurol., 1985, 231, 331). Recently, we were able to evaluate those patients. One patient, who had full long lasting remission after thymomectomy, died at the age of 69 of myocardial infarction in the course of a myasthenic relapse. Another patient had a relapse, 20 years after thymoma extirpation. Two patients had recurrent fluctuating relapses of myasthenia. One patient, who had undergone thymectomy in his childhood, developed immune thrombocytopenic syndrome. SFEMG done in 12 patients showed abnormalities in 5 cases only (mean jitter elongation, increased percentage of potential pairs with blocking and jitter elongation more than 55 microseconds). In 7 remaining patients the catamnesis covering more than 14 years revealed full clinical and electrophysiological remission. Thus, repeated analysis of the group of myasthenic patients with remission has lead us to revise our former opinion that there are no true remissions, clinical and electrophysiological, in myasthenia. They certainly occur but in some patients normalization of the electrophysiological pattern appears only several years after they have become clinically asymptomatic.

Adolescent↗

[The role of molecular genetics in diagnosis of hereditary motor-sensory neuropathy].

Hereditary motor-sensory neuropathies (HMSN) are a heterogeneous group of disorders of peripheral nervous system. Four genes in HMSN have been characterized so far i.e.: PMP22, MPZ, Cx32 and EGR-2. The advent of molecular genetic techniques over the past few years has provided identification of molecular defects in a few forms of HMSN. The present study describes the application of modern molecular genetic methods, which are used in the studies of HMSN. Southern blot hybridisation, Fluorescence in situ hybridisation (FISH), Short Tandem Repeat analysis (STR), Semiquantitative PCR analysis (SQ-PCR), Single Strand Conformation Polymorphism method (SSCP), Heteroduplex analysis (HD) and finally DNA automated sequencing are described in the present paper. In the conclusions the advantages and limits of mentioned methods of DNA analysis in HMSN have been described.

Genetic Techniques↗

[Genotype-phenotype correlation in hereditary motor-sensory neuropathy type IA associated with duplication in chromosome 17p11.2-12].

Results of clinical, electrophysiological and morphological examination, were presented in 19 patients from 8 families with hereditary motor-sensory neuropathy type I (HMSN type I) with 17p11.2-12 duplication (i.e. CMT IA). The course of the disease was rather mild, slowly progressive. Generalized demyelinating lesion of peripheral nerves was found on EMG examination, with median nerve conduction velocity between 10-20 m/s and very prolonged F wave latency. Sural nerve biopsy was characteristic of chronic demyelinating process. Phenotypic characteristics of our HMSN type I patients shows clinical, electrophysiological and morphological homogeneity, however there are some data from literature indicating possibility of intrafamilial and interfamilial variability.

Adolescent↗

[Conduction velocity in peripheral nerves in healthy and sick children].

Conduction velocity was determined in motor fibres of peripheral nerves in healthy children aged from 4 months to 15 years and in children with spinal muscular atrophy, untreated phenylketonuria, myopathies and infantile cerebral palsy. Conduction velocity equalling that in adults is reached in the ulnar and peroneal nerves at the age of about 3 years, in the median nerve somewhat later (at the age of 4-5 years). In cases of untreated phenylketonuria, myopathies and infantile cerebral palsy conduction velocity was about normal. In spinal muscular atrophy decreased conduction velocity in the youngest children may indicate delayed myelination of peripheral nerves.

Adolescent↗