A novel nonsense mutation in the human dystrophin gene.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to M Mora.
Explore the source record for details and available documents.
Characterization with a panel of six antibodies revealed abnormal dystrophin expression in 6 of 20 Duchenne muscular dystrophy (DMD) carriers examined, and in 5 of 12 Becker muscular dystrophy (BMD) carriers examined. The immunocytochemistry of muscle fibres was normal with five of the antibodies in two BMD carriers, but some muscle fibres were negative to the antibody directed against a portion of the dystrophin rod domain. Mosaicism was detected with all six antibodies in the other three BMD (but in only a small number of fibres) and in all DMD carriers muscles. Spectrin, vinculin and talin were immunolocalized in the same muscle specimens in order to assess membrane cytoskeletal integrity and to correlate their expression with that of dystrophin. These proteins, including vinculin, which was previously reported to be reduced in DMD patient muscles, were normally present on the surface of all dystrophin-deficient fibres. Muscle fibre types were characterized using monoclonal antibodies against fetal myosin and adult fast and adult slow myosin heavy chains. In both the DMD and BMD carriers, a significant reduction in type 2B fibres, as well as an increase in type 2C and fetal myosin-containing fibres was found - as has also been reported in DMD patients. Altered dystrophin expression was observed more frequently in type 2 than type 1 fibres. Dystrophin deficiency was found in a high percentage of type 2C fibres as well as in all fibres expressing fetal myosin; this suggests that dystrophin-deficient fibres are more susceptible to degeneration, leading to regeneration.
The genetic defect in a family with a mild form of Becker dystrophy was characterized by immunocytochemical, immunoblot and genomic DNA analysis in two patients and a carrier. Immunocytochemical localization on muscle preparations with a series of antibodies against different regions of the dystrophin molecule showed normal dystrophin expression with all the antibodies except anti-30 kDa antiserum. In the carrier's muscle, mosaicism was observed only with the anti-30 kDa. Immunoblot analysis revealed a band of about 250 kDa in the patients' muscles and a double band of normal and of reduced weight protein in carrier muscle. In the patients Multiplex-PCR (M-PCR) and Southern blot revealed deletions from exon 13 to exon 41. The study confirms that very mild Becker muscular dystrophy can be associated with a large intragenic deletion from the dystrophin gene.
Polymyositis is an inflammatory myopathy characterized by mononuclear cell infiltration of muscle tissue. Myocytotoxic T lymphocytes have been recognized in the infiltrates, but the muscle antigen, target of the immune attack, has not been identified. Molecular characterization of the variable regions of T cell receptors (TCRs) on the infiltrating lymphocytes can be expected to provide insights into the pathogenic process. The V alpha/beta TCR repertoire was investigated by RNA-PCR in muscle biopsies from 15 polymyositis patients and 16 controls (6 Duchenne muscular dystrophy and 10 with no inflammatory or dystrophic myopathy). A variety of rearranged variable TCR genes was found in polymyositis, V alpha 1, V alpha 5, V beta 1, and V beta 15 being the most common (present in 60-100% of patients). In Duchenne muscular dystrophy patients TCR V alpha or beta rearrangements were found although no restriction was observed; no rearrangements were found in muscles from the other controls. Sequence analysis revealed the presence of the J beta 2.1 region in 90% of the V beta 15 clones studied, no random N additions in the diversity region, and a common motif within the CDR3 region. These results suggest that selection of muscle-infiltrating T lymphocytes is antigen driven in polymyositis.
Explore the source record for details and available documents.
Aggregation and fusion of unilamellar vesicles consisting of N-acyl-N-methylphosphatidylethanolamine were studied as a function of mono- and divalent cation concentrations. The aggregation reactions were irreversible processes, as demonstrated by changes in monovalent ion concentrations and by the addition of ethylenediaminetetraacetic acid (EDTA) to chelate divalent cations, suggesting the possibility of some cation-induced vesicle fusion. An increase in the NaCl ionic strength of the vesicle suspension solutions diminishes the threshold concentration for Li+ and K+ and increases that corresponding to Mn2+, Mg2+ and Ca2+. However NaCl concentrations above 300 mM yield smaller threshold values for the divalent cation-induced processes, probably due to the increased size of phospholipid vesicles as the ionic strength of the medium increases.
We used a simple single process to recover total blood during surgery. All the process stands on a low burdensome jib and does not require additional staff in theater. Its cost is low. The indications concern all surgical operations enduring low or mean bleeding, except in septic and cancer surgery. It may be used in emergencies, even in war surgery with an incorporated source of depression.
Appearance of haemorrhages and bruises after surgery of scrotal bags contents is one of the most frequent complications in Urology. Presentation of results obtained in a prospective study carried out on 86 patients who had underwent surgery due to intrascrotal disease. In all of them and regardless of the approach used (inguinal or scrotal), suspension of bags to hypogastrium using suture traction was performed by Oesterling technique in combination to Joseph and O'Boyle's technique. Drainage was not used in any case. The article explains the characteristics of undergoing pathologies' surgical indications, describing both the technique used and the results obtained. It concludes by stating this is a useful method to prevent routine complications in scrotal surgery.
Increasing use of endourological procedures to establish a diagnosis of pyeloureteral lesions detected as a repletion deficiency during urographic study, which when they are obstructive, affect the upper urinary tract. The present report describes the use of ureterorenoscopy as a diagnostic and therapeutic procedure for the ureteral obstruction occurring in a patient with papillary necrosis secondary to analgesics abuse. The papilla was indwelt in the right distal ureter causing obstruction and symptoms of renal colic and septicemia.
Explore the source record for details and available documents.
Immunocytochemical localization and immunoblot analysis of dystrophin in muscle fibers of 11 obligate and probable, and 7 possible carriers of Duchenne and Becker muscular dystrophy revealed an abnormal expression of the protein in 3 of them. Localization of calcium and albumin, as endogenous markers of extracellular fluid penetration, showed the presence of both molecules inside some fibers lacking dystrophin. Our morphological studies show that the initial stages leading to fiber necrosis in Duchenne muscular dystrophy are present in carriers with mosaicism. Comparison of dystrophin studies with restriction fragment length polymorphism analysis and creatine kinase levels showed that neither immunocytochemical nor immunoblot techniques for dystrophin are sensitive enough to provide a basis for genetic counseling.
Explore the source record for details and available documents.
This paper describes regulatory sequences responsible for the control of human interleukin 1 beta gene expression in cells of the monocytic lineage. Hybrid plasmids containing different regions of the interleukin 1 beta gene and the bacterial chloramphenicol acetyltransferase gene were transfected into human monocytic THP-1 or U937 cells. After treatment with 12-O-tetradecanoylphorbol-13-acetate, which triggers cell differentiation, we have identified an enhancer sequence which mediates the induction of gene activity by 12-O-tetradecanoylphorbol-13-acetate. The enhancer, approximately 180 base pairs long, is located between positions -2982 and -2795 upstream from the transcriptional start site. Further analysis has shown that 132 base pairs immediately upstream from the start site of transcription are sufficient to promote constitutive expression of the gene. Additional promoter elements, located within the first intron, maximize the level of gene expression. Although activated monocytes and macrophages are the main producers of interleukin 1 beta, both the enhancer and the constitutive promoter can function in monocytic cells as well as in nonmonocytic HeLa cells.
We have studied the presence of calcitonin gene-related peptide (CGRP) immunoreactivity at the human motor end-plate in intercostal muscles from 6 normal subjects. Only a small proportion of end-plates were positively stained in the muscle. Different metabolic states at single motor end-plates or variable rates of CGRP synthesis in separate motoneurones could account for the uneven distribution of CGRP immunoreactivity at the human neuromuscular junction, or else, extremely low amounts of the peptide are below the threshold of sensitivity of the immunofluorescence method used in the present study.
Explore the source record for details and available documents.
Proliferation of adipose and fibrous connective tissue, present in various neuromuscular disorders, is remarkably abundant in those muscle diseases associated with major degenerative changes, such as the muscular dystrophies, inflammatory myopathies and chronic forms of motor neuron diseases. Fibrous-adipose replacement in skeletal muscle biopsy is an unspecific change observed whenever the muscular component is reduced due to pathological processes.
A young woman on chronic corticosteroid treatment for systemic lupus erythematosus developed a myasthenia-like syndrome 7 weeks after starting chloroquine therapy. Discontinuation of chloroquine allowed symptomatic and immunological remission within 6 months. Ocular symptoms reappeared following a second short course of chloroquine. A motor-point biopsy revealed a vacuolar myopathy with membranous bodies in intramuscular nerves. We discuss the possible role of chloroquine in the pathogenesis of a myasthenia-like syndrome.
We report our experience of needle biopsy over the past two and a half, viz. 395 cases. We find that the technique meets the needs of diagnosis and research very satisfactorily. We describe its advantages over open biopsy and recommend it in preference to the latter, provided that the necessary technical skill for processing the sample is available.