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Biomedical subjects

R Yarom

Publications and source records attributed to R Yarom.

125 records · Page 7Linked to original sources
PubMedDate not supplied

Elements in muscle measured in vivo and in vitro with X-ray spectrometry.

Calcium, iron, copper, and zinc concentrations in muscle were measured in vivo by x-ray spectrometry (XRS). The undersurface of the tongue was examined in cardiomyopathic and in normal hamsters. Values were compared to in-vitro analyses of various muscles from the same groups of animals using XRS and chemical analysis. Blood tests as well as histologic and histometric examinations were also performed. The correlated results show that XRS is a relatively sensitive and practical method for measuring chemical elements in muscle, and that it could be developed into a useful clinical test in certain neuromuscular and myocardial diseases. An interesting incidental finding was that, though all the examined muscles of myopathic animals had pathologic changes, only the tongue and myocardium, which are composed exclusively of red fibers, showed excessive calcium accumulation. This suggests either that the basic genetic aberration is not directly related to the oxidative metabolism, or that white muscles have a more efficient system for dealing with calcium overload.

Animals↗
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Element analysis of skeletal muscle in Duchenne muscular dystrophy using x-ray fluorescence spectrometry.

Concentrations of calcium, iron, copper, and zinc were simultaneously measured by x-ray fluorescence spectrometry in muscle biopsies from 11 normal subjects, 13 patients with Duchenne muscular dystrophy (DMD), and 3 DMD carriers. Calcium and copper levels were significantly elevated in patients with DMD compared to controls, and one presumptive carrier also showed an elevated calcium concentration. Comparisons with morphological data for the same samples showed a significant positive correlation between calcium concentration and the percentage area of type 2 fibers in controls, but no other correlations were found to be significant. These results illustrate the value of x-ray fluorescence spectrometry and provide further evidence for the involvement of calcium in dystrophic processes.

Adolescent↗
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X-ray microanalysis of isolated perfused rat hearts.

X-ray microanalysis was carried out on sections from isolated hearts perfused with a modified Krebs-Henseleit solution with or without isoproterenol. Changes in P, Ca and Zn concentrations could be detected after isoproterenol and some correlation with hemodynamic and morphological parameters was observed. Ratios between P/Ca in myonuclei and the ratios of interstitial cell to myofiber nucleus calcium were related directly to the state of the heart.

Animals↗
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Localised concentrations of elements in hamster cardiomyopathy. Electron microscopic x-ray microanalysis of normal and sick myocardia.

Localized elemental concentrations of Ca, P, Cl, S, and Zn were detected by X-ray microanalysis during viewing of ultrathin myocardial sections. Cardiomyopathic hamsters were compared with a healthy strain of the same age. Significant increases in calcium and chlorine concentrations were found in sick animals. These were highest in the hypertrophic stage of the disease. Phosphorus and zinc were more variable. Ratios between elements (especially P/Ca) in the same cells and of the same elements in different cell types were found to offer numerical criteria for estimating the degree of pathological change.

Animals↗
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T-2 toxin effect on isolated perfused rat hearts.

T-2 toxin is the major lethal component of several Fusarium fungi implicated in the disease of man and animals. We used isolated rats hearts to test the T-2 toxin cardiotoxicity. Electrodynamics and ultrastructural parameters were studied. The main changes consisted of decreased contractility and electrocardiographic abnormalities without much effect on heart rate or QRS and QT intervals. Ultrastructurally, swelling of myofibers and their mitochondria occurred and damage to the plasma membrane was seen. It is possible that the T-2 effect is mediated through soluble thiol to cause cytoplasmic calcium decrease and loss of plasma membrane integrity.

Animals↗
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Myofibroblasts in subepicardium after local cold injury.

Rat hearts were exposed and injured locally by direct cryoapplication. The hearts were examined 2, 4, 20 and 48 hours, 7 and 12 days later. In the first 48 hours mast cell and polymorphonuclear (mainly eosinophilic) granulocyte infiltration was followed by proliferation of mononuclear phagocytic and fibroblastic cells and new capillaries. The underlying muscle showed freeze-thaw-rigor damage, segmental intramyofiber necrosis, phagocytosis and focal regeneration. After 7 days numerous myofibroblasts appeared and they were intimately related to myofibers undergoing degeneration and repair. After 12 days there was increased fibrosis while mesothelial covering cells of the epicardium and myofibers returned to normal. It is suggested that amines released from mast cells are involved in the formation of myofibroblasts.

Animals↗
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Studies on spinal and peripheral muscles from patients with scoliosis.

This report describes part of a wider study on muscles from patients with adolescent idiopathic scoliosis. The aim of the study was to clarify if there exists a side-related pathology in the spinal musculature and if extraspinal muscles are abnormal in scoliosis patients. In scoliotic patients, both spinal and peripheral muscles showed frequent abnormalities when examined morphologically and histometrically by light and electron microscopy. Idiopathic scoliosis patients differed from the others. Morphologic pathology seemed worse on the concave side. A mild Type I fiber atrophy occurred in spinal muscles on the concave side and in the deltoids. A generalized tendency towards small myofibers was also noted. The findings suggest that there is a generalized specific neuromuscular disorder causing idiopathic scoliosis.

Adolescent↗
PubMedDate not supplied

Proprioceptive function in children with adolescent idiopathic scoliosis.

Recent studies in Japan and in Sweden have suggested that a disturbance of postural equilibrium exists in idiopathic scoliosis. Proprioceptive function is one of the factors involved, and therefore a study of proprioception in patients with adolescent idiopathic scoliosis (AIS) was carried out. No difference was noted in joint position sense and in fine motor control between 24 scoliotics and matched controls taken from a group of 70 normal children of the same age group. Blindfold weight discrimination, a test of muscle spindle and tendon stretch receptor function, also showed no abnormality in scoliotic children. The Charpentier test, thought to be a test of control of muscle spindle function, showed a tendency to an infantile response in patients with adolescent idiopathic scoliosis, while the control subjects showed a normal size-weight response.l This suggests that the muscle spindle system may be at fault in AIS and supports the suggestion that postural equilibrium reactions may be abnormal in this disease.

Adolescent↗
PubMedDate not supplied

Deltoid pathology in idiopathic scoliosis.

Histographic analyses of deltoid, trapezius, and quadriceps muscles have been performed in patients with scoliosis of different kinds and in nonscoliotic controls. The results point towards specific pathology in the deltoids, especially on the concave side of the curvature in idiopathic scoliosis. The pathology consists of an overall fiber "hypotrophy" and a type 1 area decrease, often with frank atrophy. Electromyographic examination confirmed the deltoid pathology, showing a myopathic pattern in all the concave-side deltoids and often in the convex ones as well. The cause of the cephalocaudal and side-to-side asymmetry is possibly connected to developmental and neurotrophic factors that may be operative in the complex etiology of the disease.

Adolescent↗
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Ocular findings in arthrogryposis multiplex congenita.

Close ophthalmological follow-up of a case of arthrogryposis multiplex congenita disclosed a progressing paresis of the lateral recti, a gradual decrease in the corneal blinking reflex by the age of eight weeks and a clear deterioration of the visual evoked responses by the first 16 weeks of life along with preservation of normal ERG responses. These observations are believed to represent the gradual affection of the motor and sensorial cranial nerves occurring post-natally in this case of AMC.

Adult↗
PubMedDate not supplied

Capillary and myofiber ultrastructure in endomyocardial biopsies from cyclosporine-treated heart transplant patients.

This study focuses on the ultrastructure of microvessels and myofibers in 54 endomyocardial biopsy specimens from 16 patients treated with cyclosporine after heart transplantation. Although the capillary and myofiber pathologic condition was significantly correlated with the degree of rejection, ultrastructural changes sometimes occurred in biopsy specimens with little or no histologic cellular infiltration. Immunocytochemical studies of some biopsy specimens showed that all microvessels were positive for IgM, whereas concentrations of IgG, complement, and fibrin varied. The microvascular and myofiber changes appeared to be reversible and correlated (Pearson's coefficient of correlation of myofiber vacuoles and microangiopathy, R = 0.67, p less than 0.00001). The vacuoles in myofibers resembled those in subendocardial regions of ischemic myocardium. They could, however, be related to cyclosporine toxicity because similar vacuoles have been described in kidneys of transplant patients receiving cyclosporine. We conclude that in cases of unclear graft failure in the absence of classic signs of rejection, electron microscopy could be helpful in detecting microvascular and myofiber pathologic situations that may influence myocardial function.

Adult↗