scholarly journals MYOSITIS IN MICE FOLLOWING INTRAMUSCULAR INJECTION OF VIRUSES OF THE MOUSE ENCEPHALOMYELITIS GROUP AND OF CERTAIN OTHER NEUROTROPIC VIRUSES

1949 ◽  
Vol 89 (1) ◽  
pp. 69-92 ◽  
Author(s):  
Robert Rustigian ◽  
Alwin M. Pappenheimer

A study has been made of the local effects following intramuscular injection of various neurotropic viruses. Early massive necrosis of muscle fibers accompanied by edema and acute inflammatory reaction is produced by Jungeblut's SK virus even in low concentrations. Similar but more slowly developing lesions follow the introduction of mouse encephalomyelitis GD-VII and FA strains. Strain 4727 (TO type) produces inflammatory changes with fibrosis in the intermuscular septa and necrosis of scattered individual fibers. The relatively avirulent FV strain (TO type) was not pathogenic for skeletal muscle. The Mitchell strain of lymphocytic choriomeningitis virus gives rise to a profuse lymphocytic and monocytic infiltration of the fat and connective tissue but does not cause necrosis of muscle fibers. No significant lesions resulted from intramuscular injection of the murine-adapted human poliomyelitis Lansing virus, the HF strain of herpes, a strain of Eastern equine encephalitis virus, or a still unidentified demyelinating mouse virus. Evidence is presented that the mouse encephalomyelitis virus GD-VII and Jungeblut's SK virus multiply locally in the injected limb. The GD-VII virus has been passed through four muscle to muscle passages and muscle lesions have been elicited at the same time. Specific and complete protection against myositis was obtained by anti-GD-VII and anti-SK rabbit sera.

QJM ◽  
2021 ◽  
Vol 114 (Supplement_1) ◽  
Author(s):  
Ghada Lotfy ◽  
Amel Soliman ◽  
Nevine Bahaa ◽  
Mohammed Hegazi

Abstract Background Chronic kidney disease (CKD), or chronic renal failure (CRF) as it was historically termed, includes all degrees of decreased renal function, starting from mild, and moderate, to severe chronic kidney failure. Skeletal muscle atrophy frequently complicates the course of CKD and is associated with excess morbidity and mortality. Cardiovascular diseases have been reported to be the leading causes of death in CKD patients. Chronic Kidney Disease was also reported to be associated with an increased incidence of acid-related gastrointestinal disorders. Aim of the work The aim of this study was to investigate the effect of chronic kidney disease experimentally induced by gentamicin intramuscular injection on the histological structure of gastrocnemius skeletal muscle, left ventricular cardiac muscle and smooth muscle fibers of lower esophagus. Materials and methods Twenty male adult Wistar albino rats were randomly and equally divided into two groups. Group I (control group) received physiological saline intramuscular injection, once daily for 28 consecutive days, in a dose equivalent to that taken in group II. Group II (Gentamicin-treated group) were given Gentamicin intramuscular injection for induction of CKD. Gentamicin was given as Gentamycin sulfate, 40 mg/ml (Sandoz, Switzerland), once daily, in a dose of 80 mg/kg/day for 28 days to induce CKD. After 28 days of the first injection of gentamicin, rats were anaesthetized and blood samples were collected to measure the level of serum urea and creatinine. The left kidneys, the middle third of left gastrocnemius muscle, the lateral wall of left ventricle (LV) and the gastroesophageal junction of all rats of both groups (I and II) were processed for light microscopic study. The middle third of left gastrocnemius muscle, the lateral wall of left ventricle (LV) were further processed for transmission electron microscopic study. Histomorphometrical and statistical analysis were also done. Results The LM examination revealed moderate obliteration of glomeruli, dilatation in some renal tubules and collapse in others, mainly in distal convoluted tubules, with significant fibrosis of renal parenchyma. Serum urea and creatinine levels were increased significantly. The skeletal muscle fibers of the rats in group II (CKD) showed focal areas of myofibers degeneration with siginificant fibrosis. The cardiac muscle fibers of the rats in the group II (CKD) showed focal areas of cardiomyocytes degeneration and other areas of significantly hypertrophied fibers. The smooth muscle fibers of the lower esophageal sphincter of the rats in group II (CKD) showed no significant structural changes compared with the control group, however, the myenetric plexus showed multiple pyknotic and karyolitic nuclei with vacuolated cytoplasm. In addition, insignificant increase in the amount of collagen fibers was observed in almost all layers. Conclusion CKD produced moderate atrophy of skeletal muscle fibers, significant increase in the cardiomyocyte size and no significant structural effect of smooth muscle fibers of the lower esophageal sphincter.


1999 ◽  
Vol 82 (3) ◽  
pp. 1339-1351 ◽  
Author(s):  
Colin G. Evans ◽  
Ferdinand S. Vilim ◽  
Orna Harish ◽  
Irving Kupfermann ◽  
Klaudiusz R. Weiss ◽  
...  

We observed fibers immunoreactive (IR) to serotonin (5-HT), the myomodulins (MMs), and FMRFamide on the I7-I10 complex in the marine mollusk Aplysia californica. The I7–I10 muscle complex, which produces radula opening, is innervated primarily by one motor neuron, B48. B48 is MM-IR and synthesizes authentic MMA. When B48 is stimulated in a physiological manner, cAMP levels are increased in opener muscles. cAMP increases also are seen when the MMs are applied to opener muscles but are not seen with application of the B48 primary neurotransmitter acetylcholine (ACh). Possible physiological sources of 5-HT and FMRFamide are discussed. When modulators are applied to resting opener muscles, changes in membrane potential are observed. Specifically, 5-HT, MMB, and low concentrations of MMA all depolarize muscle fibers. This depolarization is generally not sufficient to elicit myogenic activity in the absence of neural activity under “rest” conditions. However, if opener muscles are stretched beyond rest length, stretch- and modulator-induced depolarizations can summate and elicit contractions. This only occurs, however, if “depolarizing” modulators are applied alone. Thus other modulators (i.e., FMRFamide and high concentrations of MMA) hyperpolarize opener muscle fibers and can prevent depolarizing modulators from eliciting myogenic activity. All modulators tested affected parameters of motor neuron-elicited contractions of opener muscles. MMB and 5-HT increased contraction size over the range of concentrations tested, whereas MMA potentiated contractions when it was applied at lower concentrations but decreased contraction size at higher concentrations. FMRFamide decreased contraction size at all concentrations and did not affect relaxation rate. Additionally, the MMs and 5-HT increased muscle relaxation rate, decreased contraction latency, and decreased the rate at which tension was developed during motor neuron-elicited muscle contractions. Thus these modulators dramatically affect the ability of opener muscles to follow activity in the opener motor neuron B48. The possible physiological significance of these findings is discussed.


1954 ◽  
Vol 38 (2) ◽  
pp. 149-159 ◽  
Author(s):  
Emil Bozler

1. Ethylenediamine tetraacetic acid (EDTA) in low concentrations imitates all the known effects of the relaxation factor ("Marsh factor"). In extracted muscle fibers which have contracted in a solution containing adenosinetriphosphate (ATP), the addition of EBTA causes relaxation, the subsequent addition of CaCl2, contraction. 2. In fibers which have been briefly immersed in 5 MM EDTA, ATP causes rapid relaxation if Mg is also present. These fibers have essentially the same properties as briefly extracted fibers. Brief immersion into a solution containing CaCl2 restores at once the original condition. It is concluded that EDTA produces its action by firmly combining with bound Ca, thereby inactivating it. 3. In relaxed muscle fibers not only Ca, but also lowering the concentration of Mg below a critical level, causes contraction. In such fibers Mg in the lowest effective concentrations increases contraction, but the effect reverses above a certain concentration. 4. At 0° Mg in the presence of ATP has a relaxing effect without the relaxation factor. 5. The results indicate that Mg has two distinct effects in the presence of ATP. It causes contraction at low concentrations, but above a critical concentration its relaxing action prevails. The last of these effects is blocked by bound Ca. If the latter is inactivated by EDTA, Mg in sufficiently high concentrations causes relaxation. The action of the relaxation factor can similarly be explained by assuming that it acts as a complexing agent which inactivates bound Ca. 6. Previous evidence that the relaxed state depends on the formation of an enzymatically inactive ATP-protein complex was confirmed. It was found that PP in low concentrations strongly increases the relaxing effect of ATP in briefly extracted fibers.


2020 ◽  
Vol 21 (6) ◽  
pp. 2112 ◽  
Author(s):  
Patrick Belikan ◽  
Lisa Nauth ◽  
Lars-Christopher Färber ◽  
Frédéric Abel ◽  
Eva Langendorf ◽  
...  

Skeletal muscle injuries in competitive sports cause lengthy absences of athletes from tournaments. This is of tremendous competitive and economic relevance for both the athletes and their respective clubs. Therapy for structural muscle lesions aims to promote regeneration and fast-track return-to-play. A common clinical treatment strategy for muscle injuries is the intramuscular injection of calf blood compound and the homeopathic drug, Tr14. Although the combination of these two agents was reported to reduce recovery time, the regulatory mechanism whereby this occurs remains unknown. In this in vivo study, we selected a rat model of mechanical muscle injury to investigate the effect of this combination therapy on muscle regeneration. Gene expression analysis and histological images revealed that this combined intramuscular injection for muscle lesions can enhance the expression of pro-myogenic genes and proteins and accelerate muscle regeneration. These findings are novel and depict the positive effects of calf blood compound and the homeopathic drug, Tr14, which are utilized in the field of Sports medicine.


1936 ◽  
Vol 64 (5) ◽  
pp. 723-737 ◽  
Author(s):  
Peter K. Olitsky ◽  
Albert B. Sabin ◽  
Herald R. Cox

1. As mice grow older they acquire a resistance to peripheral inoculation with the Indiana and New Jersey strains of vesicular stomatitis virus and to some extent also to Western equine encephalomyelitis virus, but little or none to the Eastern strain. 2. While some mice may become resistant as early as the 30th day of life, others may still be susceptible at 1 year of age. 3. This resistance is readily demonstrable when the inoculations are made by intranasal, subcutaneous, intramuscular, intraperitoneal, and intravenous routes, but not when the virus is injected directly into the brain. 4. The resistance is not related to previous exposure to infection or to the presence of specific or nonspecific antiviral bodies in the blood. 5. No difference in susceptibility to peripheral inoculation was found in young and old guinea pigs to pseudorabies virus, and in relatively young and old Macacus rhesus monkeys to poliomyelitis virus.


1956 ◽  
Vol 39 (5) ◽  
pp. 789-800 ◽  
Author(s):  
Emil Bozler

Loading of extracted muscle fibers causes a small, sudden lengthening, followed by a slower, plastic extension, which is reversed only by active contraction. Polyphosphates in the presence of Mg strongly accelerate plastic extension, but elastic changes in length remain the same as during rigor. The modulus of elasticity on the average is about 6.2 x 107 dynes per cm.2 This value is about 40 times larger than that of rubber, if compared on a water-free basis. Extension of muscle, therefore, is almost entirely due to plastic deformation. Mg is essential for the softening action of adenosinetriphosphate (ATP) and can produce partial relaxation in the absence of a relaxation factor. After partial removal of bound Mg, ATP causes strong contraction, but only slight softening. The same condition is produced by very low concentrations of ATP in the presence of phosphocreatine. These observations show that during contraction passive mechanical properties may remain essentially like those during rigor. The constancy of elastic extensibility distinguishes contraction produced by ATP from contraction induced by non-specific agents in various fibrous structures and caused by an increase in configurational entropy.


1967 ◽  
Vol 45 (5) ◽  
pp. 833-844 ◽  
Author(s):  
G. Beaulieu ◽  
G. B. Frank ◽  
F. Inoue

By recording simultaneously from muscle fibers and from the ventral root supplying the muscle, it was found that low concentrations of tetraethylammonium (TEA) caused the muscle fibers to fire without antidromic impulses being conducted to the ventral root. Exposing the muscles to higher TEA concentrations induced action potential firing in both the muscle and the ventral root. d-Tubocurarine prevented the muscle fiber activity but did not modify the ventral root firing. The application of a single supramaximal electrical stimulus to the sciatic nerve resulted in an afterdischarge of the muscle fibers either alone or simultaneous with an afterdischarge of fibers in the ventral root. By recording from fine intramuscular motor nerve fibers with extracellular glass capillary microelectrodes while simultaneously recording from the ventral root, it was demonstrated that TEA could cause these fine intramuscular motor nerve fibers to fire without the activity being conducted antidromically to the ventral root. A consideration of the patterns of TEA-induced electrical activity and afterdischarging led to the suggestion that TEA causes these effects by displacing calcium from binding sites on the motor nerve endings, making the latter hyperexcitable and unstable and thereby causing afterdischarging and 'spontaneous' activity.


1961 ◽  
Vol 44 (5) ◽  
pp. 997-1027 ◽  
Author(s):  
R. Werman ◽  
H. Grundfest

Conversion of graded responsiveness of lobster muscle fibers to all-or-none activity by alkali-earth and tetraethylammonium (TEA) ions appears to be due to a combination of effects. The membrane is hyperpolarized, its resistance is increased, and its sensitivity to external K+ is diminished, all effects which indicate diminished K+ conductance. While the spikes are prolonged, the conductance is higher throughout the response than it is in the resting membrane. Repetitive activity becomes prominent. These effects indicate maintained high conductance for an ion which causes depolarization. This is normally Na+, since its presence in low concentrations potentiates the effects of Ba++, but the alkali-earth ions and TEA can also carry inward charge. Ba++, Sr++, and TEA appear to be more effective than is Ca++ in its normal role, which is probably to depress K+ conductance and Na inactivation. Thus, conversion of graded to all-or-none responsiveness appears to occur because of the relative increase of depolarizing inward ion flux and decrease of repolarizing outward flux.


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