scholarly journals Sarcomere Disruptions of Slow Fiber Resulting From Mountain Ultramarathon

2015 ◽  
Vol 10 (8) ◽  
pp. 1041-1047 ◽  
Author(s):  
Gerard Carmona ◽  
Emma Roca ◽  
Mario Guerrero ◽  
Roser Cussó ◽  
Alfredo Irurtia ◽  
...  

Objective:To investigate changes after a mountain ultramarathon (MUM) in the serum concentration of fast (FM) and slow (SM) myosin isoforms, which are fiber-type-specific sarcomere proteins. The changes were compared against creatine kinase (CK), a widely used fiber-sarcolemma-damage biomarker, and cardiac troponin I (cTnI), a widely used cardiac biomarker.Methods:Observational comparison of response in a single group of 8 endurance-trained amateur athletes. Time-related changes in serum levels of CK, cTnI, SM, and FM from competitors were analyzed before, 1 h after the MUM, and 24 and 48 h after the start of the MUM by 1-way ANOVA for repeated measures or Friedman and Wilcoxon tests. Pearson correlation coefficient was employed to examine associations between variables.Results:While SM was significantly (P = .009) increased in serum 24 h after the beginning of the MUM, FM and cTnI did not change significantly. Serum CK activity peak was observed 1 h after the MUM (P = .002). Moreover, serum peaks of CK and SM were highly correlated (r = .884, P = .004).Conclusions:Since there is evidence of muscle damage after prolonged mountain running, the increase in SM serum concentration after a MUM could be indirect evidence of slow- (type I) fiber-specific sarcomere disruptions.

1991 ◽  
Vol 125 (6) ◽  
pp. 609-613 ◽  
Author(s):  
Jeppe Gram ◽  
Jens Bollerslev ◽  
Henning K. Nielsen ◽  
Peter Junker

Abstract. To investigate bone collagen metabolism during vitamin D treatment, 15 healthy males (aged 28-45 years, median 34) were treated orally with calcitriol, 2 μg daily for 7 days and followed for a total of 2 weeks. The serum concentration of calcitriol rose markedly (median difference and 95% confidence limits: 49% (5-82), p<0.005) during treatment, whereas serum levels of calcidiol, and calcium remained unchanged. The serum level of procollagen type I C-terminal propeptide rose 15% (7-33, p<0.003), whereas no alterations were observed concerning serum procollagen type III N-terminal propeptide, and serum hyaluronan. The serum concentration of osteocalcin rose concomitantly (26% (12-45), p<0.003). All values returned to baseline levels within seven days after the treatment week. The serum levels of osteocalcin and procollagen type I C-terminal propeptide were positively correlated (rs=0.71, p<0.004) during the study. Serum procollagen type I C-terminal propeptide and serum osteocalcin did not correlate with serum procollagen type III N-terminal propeptide or serum hyaluronan either at baseline or after treatment. It is concluded that a short course of calcitriol administration to healthy males stimulates the biosynthesis of bone-related matrix proteins. By contrast, connective tissue components of predominantly extraosseous origin are not affected.


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 365.1-365
Author(s):  
M. Maślińska ◽  
A. Paradowska-Gorycka ◽  
A. Wajda ◽  
K. Kostyra-Grabczak ◽  
B. Kwiatkowska

Background:In the pathogensis of autoimmune mediated diseases, such as Sjögren’s syndrome (SS), interferons (IFN) and IFN pathway activation play a vital role.Objectives:We planned to assess IFNα, INFβ and INFγ expression and IFNs serum levels in SS patients and correlation of these parameters with: autoantibodies specific for SS, serum concentration of C3, C4 component of complement (C3, C4), rheumatoid factor (RF), gammaglobulins, focus score (FS) and eye dryness symptoms.Methods:Whole blood RNA was isolated from 77 SS patients [F91%vsM9%]; mean age 49,69±15.36; SS diagnosis according to EULAR/ACR 2016 criteria. The analysis of INFα, - β and - γ expression levels was based on validated TaqMan probes by ΔCT methods. Serum concentrations of rheumatoid factor (RF), C3- and C4 complement components (mg/dL) and gammaglobulins (g/dL), were assessed. Anti-Ro/SSA and/or anti-La/SSB autoantibodies were assessed by semiquantitative immunoblotting evaluation. The eye dryness and keratoconjunctivitis sicca were confirmed with Schirmer’s test (score of less than 5 mm/5’) and the ocular staining score (OSS) using lissamine green and fluorescein staining. The biopsy of minor salivary gland was performed with the histopathological evaluation of FS. The study was approved by the Bioethics Committee. Differences between groups of patients were determined using non-parametric Mann-Whitney U test or Kruskall-Wallis test with Dunn’s post hoc. Correlations were determined using non-parametric Spearman test. The level of statistical significance was set at p < 0.05.Results:IFNβ had the highest expression levels among IFNs and IFNβ serum concentrations were higher than those of IFNα and -γ. In cases with high IFNβ serum concentration lower IFNβ expression was observed. There was a highly significant correlation between IFNα and IFNβ expression (r =0.6;p=0.001). IFNβ expression (p=0.059) was higher in the group of younger (<45 y.o.) patients (n= 23; 29.9%) as compared to the group of older individuals (at least 45 y.o.). In patients with SS-A / Ro antibodies with strong antigen binding affinity (3) IFN β expression and IFNβ serum levels were highest of all IFNs. The presence of anti La/SS-B antibodies was associated with the increased IFNβ expression while not with the increased IFNβ serum concentration. In terms of IFNα expression and protein level, RF(+)patients had average higher values compared to RF(-) patients. The average mRNA level of IFNα was about 3 times lower in patients with low C3 serum concentration compared to patients with normal C3 serum concentration values. IFNβ mRNA level was 2.5 times lower in patients with low Schirmer’s test (<5mm/5’) in comparison to patients with Schirmer’s test>5mm/5’; Schirmer’s test <5mm/5’ was associated with higher IFNβ serum concentration.Conclusion:Type I IFN signature predominates in the peripheral blood of studied patients. Presented results confirmed the pivotal role of type I IFN in the disease process. The serum concentration of IFNβ and the expression of IFNβ were the highest values of those parameters for cytokines assessed in this study. A positive correlation between IFNα and IFNβ mRNA levels has been observed.Disclosure of Interests:None declared


2006 ◽  
Vol 290 (2) ◽  
pp. C567-C576 ◽  
Author(s):  
Marco A. Brotto ◽  
Brandon J. Biesiadecki ◽  
Leticia S. Brotto ◽  
Thomas M. Nosek ◽  
Jian-Ping Jin

Striated muscle contraction is powered by actin-activated myosin ATPase. This process is regulated by Ca2+ via the troponin complex. Slow- and fast-twitch fibers of vertebrate skeletal muscle express type I and type II myosin, respectively, and these myosin isoenzymes confer different ATPase activities, contractile velocities, and force. Skeletal muscle troponin has also diverged into fast and slow isoforms, but their functional significance is not fully understood. To investigate the expression of troponin isoforms in mammalian skeletal muscle and their functional relationship to that of the myosin isoforms, we concomitantly studied myosin, troponin T (TnT), and troponin I (TnI) isoform contents and isometric contractile properties in single fibers of rat skeletal muscle. We characterized a large number of Triton X-100-skinned single fibers from soleus, diaphragm, gastrocnemius, and extensor digitorum longus muscles and selected fibers with combinations of a single myosin isoform and a single class (slow or fast) of the TnT and TnI isoforms to investigate their role in determining contractility. Types IIa, IIx, and IIb myosin fibers produced higher isometric force than that of type I fibers. Despite the polyploidy of adult skeletal muscle fibers, the expression of fast or slow isoforms of TnT and TnI is tightly coupled. Fibers containing slow troponin had higher Ca2+ sensitivity than that of the fast troponin fibers, whereas fibers containing fast troponin showed a higher cooperativity of Ca2+ activation than that of the slow troponin fibers. These results demonstrate distinct but coordinated regulation of troponin and myosin isoform expression in skeletal muscle and their contribution to the contractile properties of muscle.


Methodology ◽  
2012 ◽  
Vol 8 (1) ◽  
pp. 23-38 ◽  
Author(s):  
Manuel C. Voelkle ◽  
Patrick E. McKnight

The use of latent curve models (LCMs) has increased almost exponentially during the last decade. Oftentimes, researchers regard LCM as a “new” method to analyze change with little attention paid to the fact that the technique was originally introduced as an “alternative to standard repeated measures ANOVA and first-order auto-regressive methods” (Meredith & Tisak, 1990, p. 107). In the first part of the paper, this close relationship is reviewed, and it is demonstrated how “traditional” methods, such as the repeated measures ANOVA, and MANOVA, can be formulated as LCMs. Given that latent curve modeling is essentially a large-sample technique, compared to “traditional” finite-sample approaches, the second part of the paper addresses the question to what degree the more flexible LCMs can actually replace some of the older tests by means of a Monte-Carlo simulation. In addition, a structural equation modeling alternative to Mauchly’s (1940) test of sphericity is explored. Although “traditional” methods may be expressed as special cases of more general LCMs, we found the equivalence holds only asymptotically. For practical purposes, however, no approach always outperformed the other alternatives in terms of power and type I error, so the best method to be used depends on the situation. We provide detailed recommendations of when to use which method.


2018 ◽  
Vol 2 (S1) ◽  
pp. e000127
Author(s):  
Kushali Tanna ◽  
K M Mehariya ◽  
Suchita Munsi ◽  
Charul Pujani

Aims and Objectives: To study an incidence of myocardial dysfunction in neonates admitted with perinatal asphyxia, to find out its correlation with severity of birth asphyxia and its outcome. Methods: This prospective study was conducted among 40 term neonates admitted in NICU of Civil Hospital Ahmedabad who had suffered with perinatal asphyxia (defined by WHO ), resuscitated as per NRP guidelines-2015 including both intramural and extramural admissions and who developed to hypoxic ischemic encephalopathy as defined by Levene staging. Neonates with congenital heart diseases, major central nervous system malformations and neonatal sepsis were excluded. Myocardial involvement was assessed by clinical evaluation, ECG, Creatinine Kinase Total (25-200IU/L), CK-MB (0-25IU/L) and Troponin I (0-0.03ug/L) measurements. Results: Among 40 cases, 10(25%) neonates had moderate birth asphyxia while 30(75%) had severe birth asphyxia. Respiratory distress was observed in 34(77.5%), poor spontaneous respiration 4(10%),shock in 14(35%),CCF 19(47.5%) while ECG was abnormal in 30(76.7%). Serum levels of CPK Total, CPK- MB and Troponin I were raised in 34(85%), 32(80%) and 28 (70%) neonates, respectively.  Conclusion: There was a direct correlation between ECG changes and enzymatic levels which showed increasing abnormalities with increasing with severity of HIE.  


2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1323.2-1324
Author(s):  
K. Sato ◽  
S. Mamada ◽  
C. Hayashi ◽  
T. Nagashima ◽  
S. Minota

Background:Biologic disease modifying anti-rheumatic drugs (DMARDs) have demonstrated that proinflammatory cytokines such as interleukin (IL-) 6 and tumor necrosis factor (TNF) play important roles in the pathogenesis of rheumatoid arthritis (RA). Other cytokines, such as type I interferons (IFNs), are also implicated in its pathogenesis (ref 1). However, the complete picture of the cytokine network involved in RA remains to be elucidated.Objectives:By quantifying sets of cytokines in the serum of RA patients before and after treatment with various biologic DMARDs, we sought to determine the effects of drugs on (A) type I IFNs, (B) soluble IL-6 receptors, and (C) other cytokines.Methods:52 patients with RA were treated with various biologic DMARDs (tocilizumab (TOC): 16, abatacept (ABT): 15, and TNF inhibitors (TNFi): 21). Serum samples were obtained (1) before, (2) approximately 4 weeks after (3) and approximately 12 weeks after the initiation of treatment. A suspension bead-array system was used for analysis; Bio-Plex Human Cytokine 17-plex Assay kits and Express Custom Panels (Bio-Rad), including IFN-β, IFN-α2, soluble IL-6 receptor α (sIL6Rα) and gp130 were used.Results:(1) As expected, the disease activity score 28-joiny count (DAS28) using the erythrocyte sedimentation rate (ESR) significantly decreased in all three groups (TOC, ABT and TNFi) by 12 weeks.(2) IFN-α2 was barely detected in the serum samples. IFN-β seemed to increase slightly in the ABT group, but the increase was not statistically significant.(3) The levels of sIL6Rα did not change substantially. Those of gp130 decreased slightly but significantly in the TOC group by 12 weeks.(4) The levels of IL-6 decreased significantly in the ABT group by 12 weeks. Those in the TNFi group decreased significantly at 4 weeks but not 12 weeks (Fig. 1A).(5) The levels of IL-7 decreased significantly only in the TOC group (Fig. 1B).Conclusion:(1) The biologic DMARDs tested in this study did not significantly affect the serum levels of type I IFNs in this study.(2) The decrease in gp130 in the TOC group may imply that gp130 is induced by IL-6, although whether this level of decrease has physiological significance is open to question.(3) Serum IL-6 was significantly decreased in the TNFi group at 4 weeks but not 12 weeks. TNF has been reported to induce IL-6 (ref 2), but negative feedback loop(s) may be present. Such a feedback system might make the discontinuation of TNFi difficult, even if patients are in remission.(4) IL-7 may be a target of IL-6. A higher level of IL-7 has been reported to be present in the joints of RA patients compared with osteoarthrosis and it is a cytokine implicated in the differentiation of osteoclasts (ref 3). This may partly explain the effect of TOC on preventing bone erosion in RA.References:[1]Ann Rheum Dis. 2007; 66: 1008–14[2]Rheumatology 2007; 46: 920-6[3]Rheumatology 2008; 47: 753-9Acknowledgments:We thank all the members of the Division of Rheumatology and Clinical Immunology, Department of Medicine, Jichi Medical University. We are also grateful to the patients involved in this study.Disclosure of Interests:Kojiro Sato Grant/research support from: Abbie, Pfizer, Chugai, Astellas, Mitsubishi-Tanabe, Ono, Takeda, Sachiko Mamada: None declared, Chiyomi Hayashi: None declared, Takao Nagashima: None declared, Seiji Minota: None declared


Author(s):  
Jan Mieszkowski ◽  
Andrzej Kochanowicz ◽  
Elżbieta Piskorska ◽  
Bartłomiej Niespodziński ◽  
Joanna Siódmiak ◽  
...  

Abstract Purpose/introduction To compare serum levels of bone turnover markers in athletes and non-athletes, and to evaluate the relationship between serum levels of vitamin D metabolites and exercise-induced changes in biomarker levels. Methods Sixteen elite male artistic gymnasts (EG; 21.4 ± 0.8 years-old) and 16 physically active men (the control group, PAM; 20.9 ± 1.2 years-old) performed lower and upper body 30-s Wingate anaerobic tests (LBWT and UBWT, respectively). For biomarker analysis, blood samples were collected before, and 5 and 30 min after exercise. Samples for vitamin D levels were collected before exercise. N-terminal propeptide of type I collagen (PINP) was analysed as a marker of bone formation. C-terminal telopeptide of type I collagen (CTX) was analysed as a marker of bone resorption. Results UBWT fitness readings were better in the EG group than in the PAM group, with no difference in LBWT readings between the groups. UBWT mean power was 8.8% higher in subjects with 25(OH)D3 levels over 22.50 ng/ml and in those with 24,25(OH)2D3 levels over 1.27 ng/ml. Serum CTX levels increased after both tests in the PAM group, with no change in the EG group. PINP levels did not change in either group; however, in PAM subjects with 25(OH)D3 levels above the median, they were higher than those in EG subjects. Conclusion Vitamin D metabolites affect the anaerobic performance and bone turnover markers at rest and after exercise. Further, adaptation to physical activity modulates the effect of anaerobic exercise on bone metabolism markers.


2021 ◽  
pp. 028418512110188
Author(s):  
Kerem Ozturk ◽  
David Nascene

Background An association between consecutive administrations of macrocyclic gadolinium-based contrast agent (mcGBCA) gadobutrol and linear (L)-GBCA gadopentetate dimeglumine and gadolinium retention in the pediatric brain remains incompletely understood. Purpose To compare signal intensity (SI) changes in the dentate nucleus (DN) on unenhanced T1-weighted imaging (T1WI) in children who obtained mcGBCA gadobutrol with those who had previously received L-GBCA gadopentetate dimeglumine. Material and Methods This retrospective study included 27 children who received L-GBCA gadopentetate dimeglumine followed by mcGBCA gadobutrol and two different control groups matched for age and sex for both periods, each involving 27 individuals with no GBCA administration from January 2010 to January 2020. DN-to-middle cerebellar peduncle (MCP) SI ratios on T1WI were determined. A repeated-measures ANOVA was performed to compare the T1WI SI ratio between children exposed to GBCA in each of the two periods and controls. Pearson correlation analysis was conducted to determine any correlation between SI ratios and confounding parameters. Results T1WI SI ratio was significantly higher in those who had only L-GBCA (1.005±0.087) or subsequent mcGBCA gadobutrol (1.002±0.104) than in control groups 1 (0.927±0.041; P<0.001) and 2 (0.930±0.041; P=0.002), respectively, but no significant difference of the T1WI SI ratio was noted between L-GBCA period and subsequent mcGBCA gadobutrol period ( P=0.917). T1WI SI ratios and the L-GBCA administration number revealed a modest but significant correlation (correlation coefficient=0.034; P=0.016). Conclusion Previous administration of gadopentetate dimeglumine is associated with increased T1WI SI in the DN, while subsequent administration of gadobutrol does not demonstrate any additional SI increase in the pediatric brain.


2021 ◽  
Vol 12 (01) ◽  
pp. 106-111
Author(s):  
Srinivasan Radhakrishnan ◽  
Swathy Moorthy ◽  
Sudish Gadde ◽  
Krishnaswamy Madhavan

Abstract Background Stroke (cerebrovascular accident) has for long been a global burden in terms of its morbidity and mortality. Serum levels of cardiac enzymes such as creatine kinase-MB (CK-MB) component, troponin T, and brain natriuretic peptide have been found to be elevated among the patients with stroke and also serve to prognosticate these patients. The serum levels of these enzymes correlate directly to the severity of stroke in these patients. Objective Elevated cardiac enzymes among patients with acute cerebrovascular accidents are not uncommon despite the patients not having any cardiac problems. We aimed to identify the occurrence of elevated cardiac enzymes among patients with acute stroke and their correlation with the severity of stroke. Materials and Methods Our study included 100 patients of acute stroke with no previous history of cardiac ailments. Serum levels of troponin I and CK-MB were analyzed among these patients using enzyme-linked immunosorbent assay method within the first 2 hours of admission. Patients outcome during the hospital stay were analyzed. Stroke severity was assessed using the National Institute of Health Stroke score (NIHS score) and the modified Rankin Score (mRS). The cardiac enzyme levels were correlated with these scores. Results Twenty-eight percent of patients had elevated troponin I, while 72% patients had normal levels with the mean values of 10.36 to 106.54 ng/mL and 0.00 to 0.02 ng/mL, respectively. CK-MB levels were found elevated among 14% patients and normal among 86% patients with mean values of 5.8 to 124.36 and 0.0 to 4.3 ng/mL, respectively. Among the six patients who succumbed to death, three patients had increased troponin I and four had elevated CK-MB. NIHS scores of 21.0357±6.79 and 105.277±5.564 were seen in patients with elevated and normal troponin I, whereas NIHS scores of 20.4285±8.658 and 11.8721±9.273 were seen among patients with increased and normal CK-MB, respectively. The mRS scores were 4.3214±0.367, 2.4305±1.374, 4.2143±1.412, and 2.756±1.749 ng/mL among the patients with elevated and normal troponin I and CK-MB, respectively. Conclusion The mean values of cardiac enzymes troponin I and CK-MB were higher among patients with higher scores of NIHS and mRS. Among them, troponin I was very significant and it may serve as an early biomarker for the severity of stroke and hint on early cardiac evaluation among these patients.


Sign in / Sign up

Export Citation Format

Share Document