Calcification In Skeletal Muscle Research Articles

A severe case of thrombocytopenia, anasarca, fever, renal insufficiency or reticulin fibrosis, and organomegaly syndrome with myocardial and skeletal muscle calcification despite hypocalcemia: a case report

BackgroundTAFRO (thrombocytopenia, anasarca, fever, renal insufficiency or reticulin fibrosis, and organomegaly) syndrome is a recently recognized disease with a variety of presentations of variable severity. In acute settings, this disease also involves organ dysfunction because of the associated systemic inflammation. However, cases of TAFRO syndrome with myocardial and/or skeletal muscle calcification have never been reported.Case presentationA 24-year-old healthy young Asian man was admitted with intermittent epigastric pain and fever for 2 weeks. Computed tomography revealed pleural effusion, ascites and systemic lymphadenopathy. Laboratory tests showed thrombocytopenia, elevated C-reactive protein, hypoalbuminemia, anemia and renal dysfunction. Based on these findings and bone marrow biopsy, we diagnosed his disease as TAFRO syndrome and commenced hemodialysis for the renal dysfunction. However, he developed refractory hypocalcemia with unstable vital signs, for which we administered calcium gluconate hydrate. Thereafter, myocardial and skeletal muscle calcification was revealed radiologically, with the myocardial calcification causing sick sinus syndrome. He was treated with tocilizumab and finally discharged in an ambulatory condition after prolonged hospitalization, with residual calcific lesions.ConclusionThis is the first report of a patient with TAFRO syndrome and the complication of organ calcification. The etiology of calcification in this case is not clear. Systemic inflammation with possible hypercytokinemia might have been involved in the unexpected complication of systemic calcification. It is important to carefully handle the general management of TAFRO syndrome because of the possibility of various complications.

Enhancing Plasmin Activity Prevents Diet‐Induced Skeletal Muscle Calcification Following Injury

Enhancing Plasmin Activity Prevents Diet‐Induced Skeletal Muscle Calcification Following Injury

Validation of a Radiography-Based Quantification Designed to Longitudinally Monitor Soft Tissue Calcification in Skeletal Muscle.

IntroductionSoft tissue calcification, including both dystrophic calcification and heterotopic ossification, may occur following injury. These lesions have variable fates as they are either resorbed or persist. Persistent soft tissue calcification may result in chronic inflammation and/or loss of function of that soft tissue. The molecular mechanisms that result in the development and maturation of calcifications are uncertain. As a result, directed therapies that prevent or resorb soft tissue calcifications remain largely unsuccessful. Animal models of post-traumatic soft tissue calcification that allow for cost-effective, serial analysis of an individual animal over time are necessary to derive and test novel therapies. We have determined that a cardiotoxin-induced injury of the muscles in the posterior compartment of the lower extremity represents a useful model in which soft tissue calcification develops remote from adjacent bones, thereby allowing for serial analysis by plain radiography. The purpose of the study was to design and validate a method for quantifying soft tissue calcifications in mice longitudinally using plain radiographic techniques and an ordinal scoring system.MethodsMuscle injury was induced by injecting cardiotoxin into the posterior compartment of the lower extremity in mice susceptible to developing soft tissue calcification. Seven days following injury, radiographs were obtained under anesthesia. Multiple researchers applied methods designed to standardize post-image processing of digital radiographs (N = 4) and quantify soft tissue calcification (N = 6) in these images using an ordinal scoring system. Inter- and intra-observer agreement for both post-image processing and the scoring system used was assessed using weighted kappa statistics. Soft tissue calcification quantifications by the ordinal scale were compared to mineral volume measurements (threshold 450.7mgHA/cm3) determined by μCT. Finally, sample-size calculations necessary to discriminate between a 25%, 50%, 75%, and 100% difference in STiCSS score 7 days following burn/CTX induced muscle injury were determined.ResultsPrecision analysis demonstrated substantial to good agreement for both post-image processing (κ = 0.73 to 0.90) and scoring (κ = 0.88 to 0.93), with low inter- and intra-observer variability. Additionally, there was a strong correlation in quantification of soft tissue calcification between the ordinal system and by mineral volume quantification by μCT (Spearman r = 0.83 to 0.89). The ordinal scoring system reliably quantified soft tissue calcification in a burn/CTX-induced soft tissue calcification model compared to non-injured controls (Mann-Whitney rank test: P = 0.0002, ***). Sample size calculations revealed that 6 mice per group would be required to detect a 50% difference in STiCSS score with a power of 0.8. Finally, the STiCSS was demonstrated to reliably quantify soft tissue calcification [dystrophic calcification and heterotopic ossification] by radiographic analysis, independent of the histopathological state of the mineralization.ConclusionsRadiographic analysis can discriminate muscle injury-induced soft tissue calcification from adjacent bone and follow its clinical course over time without requiring the sacrifice of the animal. While the STiCSS cannot identify the specific type of soft tissue calcification present, it is still a useful and valid method by which to quantify the degree of soft tissue calcification. This methodology allows for longitudinal measurements of soft tissue calcification in a single animal, which is relatively less expensive, less time-consuming, and exposes the animal to less radiation than in vivo μCT. Therefore, this high-throughput, longitudinal analytic method for quantifying soft tissue calcification is a viable alternative for the study of soft tissue calcification.

Exacerbated skeletal muscle inflammation and calcification in the acute phase of infection by Mexican Trypanosoma cruzi DTUI strain.

A murine model was used to study the histopathological aspects and cytokine expression levels in skeletal muscle provoked by the infection with Mexican TcI strains. BALB/c mice were inoculated with the virulent Querétaro strain and the nonvirulent Ninoa strain. Parasite numbers were counted in blood and skeletal muscle at different times post-infection, and real time-PCR expression levels of the cytokines IL-12, IL-4, IL-10, IFN-γ, and TNF-α were evaluated. In the acute phase of infection, a high parasitic load, both in blood and skeletal muscle, was detected. The histopathological analyses showed an exacerbated inflammation and granulomatous-like infiltrate with the Querétaro strain. Interestingly, extensive calcification areas were observed in the skeletal muscle surrounded by inflammatory infiltrates. TNF-α and IL-10 expression exhibited a significant increase at the peak of infection. In summary, Querétaro strain, a Mexican TcI strain, is virulent enough to induce high inflammation and calcification in skeletal muscle of the hind limbs, which could be related to high expression levels of TNF-α.

T.P.12 Dietary phosphate intake and exercise-induced stress induce severe muscle necrosis in adult mdx mice

Progressive muscle degeneration, ectopic calcification in skeletal muscle, and high serum phosphate levels are characteristic features of muscular dystrophy especially in mdx mice. However, the effects of dietary phosphate intake on ectopic calcification and muscle pathology are not well studied. We previously reported that increased dietary phosphate intake caused elevated serum phosphate (Pi) levels, severe ectopic calcification and reduced muscle function in mdx mice. In contrast, lowering phosphate intake ameliorated the pathogenesis of the mice. In this study, we examined the effects of dietary phosphate intake and exercise-induced stress on muscle pathology of 90days old mdx mice (adult mdx mice). Voluntary running on activity wheel (VR) increases physical activity and negatively affects muscle pathology of the mice. We found that 10days of VR exacerbated muscle degeneration, increased macrophage infiltration and increased ectopic calcification in limb muscles of high-phosphate fed adult mdx mice. Tibialis anterior (TA) muscle, which consists mostly of muscle fibers with central nuclei and minimal necrotic areas when the mice were kept in a normal cage, was the most affected muscle by VR. Since numerous muscle fibers were embryonic heavy chain positive, high-phosphate intake did not interfere with muscle regeneration but dramatically progressed muscle degeneration. Interestingly, exercise and low-phosphate intake had relatively few areas of group degeneration and no ectopic calcification in TA muscle of mdx mice. The muscle pathologies of the exercised and non-exercised mdx mice fed low-Pi diet were similar. Therefore we conclude that high dietary phosphate intake progresses the pathogenesis of muscular dystrophy, and lowering phosphate intake could increase resistance to exercise-induced damage.

Changes in tissue calcium and phosphorus content and plasma concentrations of parathyroid hormone and calcitonin after long-term magnesium deficiency in rats.

The present study was undertaken to investigate the effect of dietary magnesium (Mg) deficiency on plasma levels of parathyroid hormone (PTH) and calcitonin (CT), and the changes in tissue calcium (Ca) and phosphorus (P) content. Wistar rats were fed an Mg-deficient diet. Plasma levels of PTH and CT, and Ca and P content in plasma, whole blood, skeletal muscle, heart, kidney, femoral bone and brain, were determined after 7, 35, 42, 49, 56, 63 and 70 days. Mg deficiency significantly increased plasma levels of ionic Ca after 1 week of deficiency, and significantly increased total Ca in plasma and whole blood after 5 weeks. Whole blood and plasma levels of P decreased significantly after 8 and 5 weeks, respectively, in comparison with values obtained in pair-fed control rats. Plasma levels of CT were not modified by hypercalcemia and hypomagnesemia. Plasma PTH decreased significantly during the first 3 weeks, then recovered gradually, reaching control values in week 7 and remaining stable thereafter, despite elevated levels of ionic Ca. The Mg-deficient diet led to calcification in skeletal muscle, heart, kidney and femur, detectable as early as week 5. However, P content increased only in kidney after 1 week, decreased in heart and femur after 5 weeks, and did not change in muscle. The Mg-deficient diet did not significantly modify Ca or P content in brain. Mg deficiency led to tissue calcification and decreased P levels in blood, heart, and femur. These changes did not affect CT secretion. PTH appeared to be more closely related with hypomagnesemia than with hypercalcemia.

Demonstration of CT Hyperdensity in Patients with Acute Renal Failure Associated with Rhabdomyolysis

Abnormal hyperdensity consistent with skeletal muscle calcification was shown by CT in four of eight (50%) patients with rhabdomyolysis. This finding correlated significantly with antecedent hypocalcemia (p = 0.01) and renal insufficiency (p = 0.03). In patients with rhabdomyolysis, CT can show abnormal skeletal muscle hyperdensity consistent with calcification. A work-up for hypocalcemia and renal insufficiency should be initiated when this finding is demonstrated. Noncontrast CT could be useful in cases of acute renal failure of unknown etiology to help diagnose occult rhabdomyolysis.

POST‐ISCHEMIC CALCIFICATION IN SKELETAL MUSCLE

The extent of post-ischemic calcification in skeletal muscle was studied in rats subjected to 5.5 h of ischemia followed by periods of reperfusion ranging from 30 min to 16 h. Sections from the tibialis posterior and soleus muscle were stained with alizarin red S (ARS) and were inspected with light microscopy. The number of ARS-positive cells increased during the first 5 h of reperfusion. The extent of calcification varied between fibers and the pattern of calcification appeared to be dependent on fiber type. In some fast glycogenolytic fibers (FG) central calcifications, probably representing mitochondria, were observed. In fast oxidative glycogenolytic (FOG) and slow oxidative (SO) fibers the most common pattern was an ARS-positive granulation, probably representing calcification of sarcoplasmic reticulum and/or mitochondria. The granulation was more extensive in FOG than in SO fibers. In some areas extracellular ARS-positive material was observed. In such areas, which probably represent areas of no-reflow, no calcification of muscle fibers was observed.