Mechanisms underlying Andersen's syndrome pathology in skeletal muscle are revealed in human myotubes

2009 ◽  
Vol 297 (4) ◽  
pp. C876-C885 ◽  
Author(s):  
S. Sacconi ◽  
D. Simkin ◽  
N. Arrighi ◽  
F. Chapon ◽  
M. M. Larroque ◽  
...  

Andersen's syndrome is a rare disorder that has been defined with a triad: periodic paralysis, cardiac arrhythmia, and development anomalies. Muscle weakness has been reported in two-thirds of the patients. KCNJ2 remains the only gene linked to Andersen's syndrome; this gene encodes for the α-subunit of the strong inward-rectifier K+ channel Kir2.1. Several studies have shown that Andersen's syndrome mutations lead to a loss of function of the K+ channel activity in vitro. However, ex vivo studies on isolated patient muscle tissue have not been reported. We have performed muscle biopsies of controls and patients presenting with clinically and genetically defined Andersen's syndrome disorder. Myoblasts were cultured and characterized morphologically and functionally using the whole cell patch-clamp technique. No morphological difference was observed between Andersen's syndrome and control myoblasts at each passage of the cell culture. Cellular proliferation and viability were quantified in parallel with direct cell counts and showed no difference between control and Andersen's syndrome patients. Moreover, our data show no significant difference in myoblast fusion index among Andersen's syndrome and control patients. Current recordings carried out on myotubes revealed the absence of an inwardly rectifying Ba2+-sensitive current in affected patient cells. One consequence of the Ik1 current loss in Andersen's syndrome myotubes is a shift of the resting membrane potential toward depolarizing potentials. Our data describe for the first time the functional consequences of Andersen's syndrome mutations ex vivo and provide clues to the K+ channel pathophysiology in skeletal muscle.

2013 ◽  
Vol 26 (05) ◽  
pp. 356-365 ◽  
Author(s):  
K. L. Wendelburg ◽  
S. Tepic ◽  
S. M. Stover ◽  
T. Garcia-Nolen ◽  
P. B. Stearns ◽  
...  

SummaryElbow dysplasia, primarily affecting the medial compartment, is the most common cause of lameness in the thoracic limb. Elbow arthroplasty is an option for end stage or severely affected patients. The purpose of this study was to compare ex vivo axial load to failure of an implanted novel elbow arthroplasty system to control limbs. The partial arthroplasty is a medial compartmental, unconstrained system, intended to allow conversion to total arthroplasty. We hypothesized that there would not be any significant difference between implanted and controlled limbs when loaded to failure. Six pairs of medium mixed breed canine cadaveric thoracic limbs were prepared for comparison of failure loading of control and implanted limbs. Axial compression was performed using a mechanical testing system. Failure loads were normalized to bodyweight. The mean normalized failure load (N/kg) for the implanted limbs and control limbs were 2.47 (range: 1.62-3.38) and 2.68 (range: 2.25-3.25), respectively. An implanted to control ratio of 0.93 ± 0.19 was calculated. The difference between paired control and implanted limbs in normalized failure loading was not significant (p = 0.38). There were not any differences noted in the yield load (p = 0.30), stiffness (p = 0.62), or energy (0.58). Failure modes were recorded. We concluded that the differences between implanted and control limbs in supra-physiologic axial load to failure were not significant.


2014 ◽  
Vol 21 (2) ◽  
pp. 101-106 ◽  
Author(s):  
Warren J Davidson ◽  
John Dennis ◽  
Stephanie The ◽  
Belinda Litoski ◽  
Cora Pieron ◽  
...  

BACKGROUND: Induced sputum cell counts are a noninvasive and reliable method for evaluating the presence, type and degree of airway inflammation in patients with asthma. Currently, standard nebulizer devices used for sputum induction in multiple patients are labelled as single-patient devices by the manufacturer, which conflicts with infection prevention and control requirements. As such, these devices cannot feasibly be used in a clinical sputum induction program. Therefore, there is a need to identify alternative nebulizer devices that are either disposable or labelled for multi-patient use.OBJECTIVE: To apply validated rigorous, scientific testing methods to identify and validate commercially available nebulizer devices appropriate for use in a clinical sputum induction program.METHODS: Measurement of nebulized aerosol output and size for the selected nebulizer designs followed robust International Organization for Standardization methods. Sputum induction using two of these nebulizers was successfully performed on 10 healthy adult subjects. The cytotechnologist performing sputum cell counts was blinded to the type of nebulizer used.RESULTS: The studied nebulizers had variable aerosol outputs. The AeroNeb Solo (Aerogen, Ireland), Omron NE-U17 (Omron, Japan) and EASYneb II (Flaem Nuova, Italy) systems were found to have similar measurements of aerosol size. There was no significant difference in induced sputum cell results between the AeroNeb Solo and EASYneb II devices.DISCUSSION: There is a need for rigorous, scientific evaluation of nebulizer devices for clinical applications, including sputum induction, for measurement of cell counts.CONCLUSION: The present study was the most comprehensive analysis of different nebulizer devices for sputum induction to measure cell counts, and provides a framework for appropriate evaluation of nebulizer devices for induced sputum testing.


2019 ◽  
Vol 5 (2) ◽  
pp. 118
Author(s):  
Yakup Aktas ◽  
Ismail Gokhan

Objective: This study aims at examining the body composition of male football players who perform regular football training by Bioelectrical Impedance (BIA) method and comparing it with a healthy control group and investigating the effect of regular exercise on body composition.Materials and Methods: A total of 60 people participated in the study, including 30 volunteer male football players performing football trainings regularly from 11 Nisan Football Club playing in Turkey Football Federation Regional Amateur League (BAL) and 30 healthy volunteer control group consisting of male students from Harran University Medical Faculty. Both groups’ ages and body mass indexes are similar to each other.  Bioelectrical Impedance (BIA) method was used for Osseosis, skeletal muscle weight (SMM), body mass index (BMI), body fat percentage (BFP), waist hip ratio (WHR), and basal metabolism parameters of the participants. The data obtained were evaluated with SPSS 23.0 statistical package program, and the significance level was evaluated as p < 0.01 and p < 0.05.Findings: There was no statistically significant difference between the values of age, height, weight, intracellular fluid, extracellular fluid, protein, mineral, skeletal muscle weight (SMM), body mass index (BMI) and muscle ratios of the experimental and control groups (p > 0.05). When the parameters of basal metabolism, Osseosis and skeletal muscle weight of the experimental group were discussed, no significant relationship was detected, although they were high numerically (p > 0.05). It was determined that the body fat percentage (BFP) of the experimental and control groups was correlated at p < 0.01 level and waist-hip ratio was correlated (WHR) at p < 0.05 level, which was statistically significant. As a result, although there was no significant difference between BMI values between the football players and the control group, the fact that the players' lower BMI values and lower waist-hip ratios showed that regular training reduces the risk of developing chronic diseases.


2017 ◽  
Vol 29 (1) ◽  
pp. 149
Author(s):  
F. Sosa ◽  
J. Fernando de la Torre ◽  
H. Álvarez ◽  
S. Pérez ◽  
M. E. Kjelland ◽  
...  

The actual challenge for the majority of research centers involves the embryo culture medium, since it is known that the culture medium plays a large role in determining embryo quality. Pterostilbene (PT) is a natural analogue of Resveratrol, an antioxidant that can reduce lipids in embryos, but no reports exist of PT being used with IVF-produced embryos or gametes. The objective of the present research was to evaluate the effect of PT in culture media CDM1 and CDM2 on embryo production, cell count, lipid accumulation, and reactive oxygen species (ROS). A total of 4 concentrations of PT and a control were evaluated, i.e. 3, 1, 0.33, 0.11, and 0 μM, in 2 separate experiments. The first experiment was performed using 6 replicates (n = 204) to evaluate blastocyst production (n = 201) and determine the percentage of lipids using the stain Sudan-Black, (n = 100). Hoechst 33258 and propidium iodide were used for determining cell counts. The second experiment was performed using 7 replicates, the effect of using PT (0.33 μM) was compared with a control with 2 O2 concentrations (5 and 20%) for evaluating ROS production (n = 124). Blastocysts without zona pellucida were incubated 48 h at 38.5°C in PBS (without polyvinyl alcohol) with 60 μL of ro-green fluorescent protein. After incubation, 25 μL of 4′,6-diamidino-2-phenylindole (1 mg mL−1) was added and incubated for 5 min. A fluorescence microscope was used and positive ROS particles digitized using Photoshop CS6 and quantified using the program ImageJ®. The data were transformed to arcsin values for subsequent analysis. In the first experiment, ANOVA and least significant difference tests were used to determine statistical significance (Statgraphics). No significant differences were found among treatments (P > 0.05) for the internal cell mass: 3, 1, 0.33, 0.11 μM PT (29.2 ± 5.2; 28.9 ± 3.8; 22.2 ± 3.2; 29.0 ± 1.7, respectively) and the control (27.0 ± 1.7). The cells of the trophectoderm did not differ (P > 0.05) between treatments (31.7 ± 4.8; 31.3 ± 3.9; 38.6 ± 3.5; 30.8 ± 1.8) and control (33.4 ± 2.1). Total cells did not differ (P > 0.05) between treatments (72.0 ± 9.8; 82.6 ± 4.3; 94.8 ± 12.8; 73.2 ± 9.2) and control (83.8 ± 7.7). Embryo production (Day 8) was greater for control (33.5 ± 3.0) versus treatments (14.1 ± 1.7; 19.4 ± 1.9; 21.1 ± 2.6; 20.8 ± 2.1) (P < 0.05); however, PT reduced the percentage of lipids (11.0 ± 0.8; 10.7 ± 0.9; 11.6 ± 1.3; 11.3 ± 1.1) within the cytoplasm of the embryos (P < 0.05) versus control (17.01 ± 1.20). In the second experiment, a factorial 2 × 2 matrix demonstrated that the O2 concentration did not have an effect on ROS (P > 0.05); however, the PT had a significant effect on the reduction of ROS (P < 0.05), i.e. a negative correlation, r = −0.835. In summary, we determined that PT did not improve the production of blastocysts but resulted in a significant reduction of ROS and lipids.


2021 ◽  
Vol 186 (Supplement_1) ◽  
pp. 358-363
Author(s):  
Elizabeth Rohde ◽  
Maryam Goudarzi ◽  
Maria Madajka ◽  
Sayf Al-Deen Said ◽  
Carlos Ordenana ◽  
...  

ABSTRACT Introduction Ex vivo normothermic limb perfusion (EVNLP) provides several advantages for the preservation of limbs following amputation: the ability to maintain oxygenation and temperature of the limb close to physiological values, a perfusion solution providing all necessary nutrients at optimal concentrations, and the ability to maintain physiological pH and electrolytes. However, EVNLP cannot preserve the organ viability infinitely. We identified evidence of mitochondrial injury (swelling, elongation, and membrane disruption) after 24 hours of EVNLP of human upper extremities. The goal of this study was to identify metabolic derangements in the skeletal muscle during EVNLP. Materials and Methods Fourteen human upper extremities were procured from organ donors after family consent. Seven limbs underwent EVNLP for an average of 41.6 ± 9.4 hours, and seven contralateral limbs were preserved at 4°C for the same amount of time. Muscle biopsies were performed at 24 hours of perfusion, both from the EVNLP and control limbs. Perturbations in the metabolic profiles of the muscle during EVNLP were determined via untargeted liquid chromatography–mass spectrometry (MS) operated in positive and negative electrospray ionization modes, over a mass range of 50 to 750 Da. The data were deconvoluted using the XCMS software and further statistically analyzed using the in-house statistical package, MetaboLyzer. Putative identification of metabolites using exact mass within ±7 ppm mass error and MS/MS spectral matching to the mzCloud spectral library were performed via Compound Discoverer v.2.1 (Thermo Scientific, Fremont, CA, USA). We further validated the identity of candidate metabolites by matching the fragmentation pattern of these metabolites to those of their reference pure chemicals. A nonparametric Mann–Whitney U-test was used to compare EVNLP and control group spectral features. Differences were considered significantly different when P-value &lt; 0.05. Results We detected over 13,000 spectral features of which 58 met the significance criteria with biologically relevant putative identifications. Furthermore we were able to confirm the identities of the ions taurine (P-value: 0.002) and tryptophan (P-value: 0.002), which were among the most significantly perturbed ions at 24 hours between the experimental and control groups. Metabolites belonging to the following pathways were the most perturbed at 24 hours: neuroactive ligand-receptor interaction (P-values: 0.031 and 0.036) and amino acid metabolism, including tyrosine and tryptophan metabolism (P-values: 0.015, 0.002, and 0.017). Taurine abundance decreased and tryptophan abundance increased at 24 hours. Other metabolites also identified at 24 hours included phenylalanine, xanthosine, and citric acid (P-values: 0.002, 0.002, and 0.0152). Discussion This study showed presence of active metabolism during EVNLP and metabolic derangement toward the end of perfusion, which correlated with detection of altered mitochondrial structure, swelling, and elongation.


Author(s):  
Derek Waddell ◽  
Kim Fredricks

L-glutamine is the most abundant amino acid found in human muscle and plays an important role in protein synthesis. It is, therefore, believed that by increasing L-glutamine levels, protein metabolism can be increased, resulting in skeletal muscle growth. The goal of this research was to determine if increased L-glutamine levels enhanced muscle growth in mice. Comparisons between the contractile force of the gastrocnemis muscles of a control group and a group that received the supplement through their water supply were intended to determine if muscle growth occurred. T-tests were used to compare the contractile forces of the experimental and control mice. There was a significant difference between the contractile forces of the experimental and control groups. This suggests that L-glutamine supplementation increased the muscle growth of the experimental mice.


2016 ◽  
Vol 311 (4) ◽  
pp. E706-E719 ◽  
Author(s):  
Laurent Bultot ◽  
Thomas E. Jensen ◽  
Yu-Chiang Lai ◽  
Agnete L. B. Madsen ◽  
Caterina Collodet ◽  
...  

AMP-activated protein kinase (AMPK) plays diverse roles and coordinates complex metabolic pathways for maintenance of energy homeostasis. This could be explained by the fact that AMPK exists as multiple heterotrimer complexes comprising a catalytic α-subunit (α1 and α2) and regulatory β (β1 and β2)- and γ (γ1, γ2, γ3)-subunits, which are uniquely distributed across different cell types. There has been keen interest in developing specific and isoform-selective AMPK-activating drugs for therapeutic use and also as research tools. Moreover, establishing ways of enhancing cellular AMPK activity would be beneficial for both purposes. Here, we investigated if a recently described potent AMPK activator called 991, in combination with the commonly used activator 5-aminoimidazole-4-carboxamide riboside or contraction, further enhances AMPK activity and glucose transport in mouse skeletal muscle ex vivo. Given that the γ3-subunit is exclusively expressed in skeletal muscle and has been implicated in contraction-induced glucose transport, we measured the activity of AMPKγ3 as well as ubiquitously expressed γ1-containing complexes. We initially validated the specificity of the antibodies for the assessment of isoform-specific AMPK activity using AMPK-deficient mouse models. We observed that a low dose of 991 (5 μM) stimulated a modest or negligible activity of both γ1- and γ3-containing AMPK complexes. Strikingly, dual treatment with 991 and 5-aminoimidazole-4-carboxamide riboside or 991 and contraction profoundly enhanced AMPKγ1/γ3 complex activation and glucose transport compared with any of the single treatments. The study demonstrates the utility of a dual activator approach to achieve a greater activation of AMPK and downstream physiological responses in various cell types, including skeletal muscle.


1961 ◽  
Vol 200 (4) ◽  
pp. 824-826 ◽  
Author(s):  
Edwin L. Stewart ◽  
Louis G. Welt

Pregnant rats were provided with a potassium-deficient diet on the day of mating. One group was sacrificed at 12–13 days of gestation and another group at 21 days. A third group was depleted of potassium acutely by utilizing peritoneal dialysis with an isotonic NaHCO3 solution. In all groups maternal serum and muscle potassium were found to be significantly lower and maternal serum CO2 significantly higher in the experimental animals than in the controls. However no significant difference in total fetal potassium concentrations was found when experimental and control animals were compared. As late as 15–17 days of gestation the total fetal potassium concentrations were found to be nearly double those of maternal skeletal muscle, but on day 21 the total fetal and the maternal muscle values were roughly equivalent. The mean dry weight of the experimental 21-day fetuses was significantly lower than that of the control fetuses. The mechanism of fetal sparing in maternal potassium depletion cannot be determined from the present data.


2017 ◽  
Vol 2 (4) ◽  
pp. 77-80
Author(s):  
Yusef Dostar ◽  
Alireza Gorjani ◽  
Mehrdad Hashemi ◽  
Rambod Rezapour Shahir

Background and objective: To study the time-dependent effects of ischemia – reperfusion on myocardium cells. Methodology: Male SD rats (270-330gr) were randomly grouped in four groups of 10 in an experimental study. After anesthesia using pentobarbital sodium (50-60 IP-kg/mg) the rats’ hearts in the treatment groups were isolated immediately and connected to langendorff apparatus with krebs solution at 37ºC and a fixed pressure. During stabilization, 30m ischemia and 60, 90, and 120min reperfusion was carried out on the hearts. Hearts of the control group remained intact. Immunhistochemistry of apoptotic cells was performed using TUNEL POD Kit and positive TUNEL myocardium cells of each group, in five microscopic view fields, was counted. The results were represented as mean ± SD. Findings: Apoptotic cell counts in control group was 1±0.4, and this figure in the treatment groups T/60min, T/90min, and T/120min was 2.0±0.5, 3.0±0.3, and 6.0±0.3 respectively. Comparison between the treatment groups and control group was carried out using one-way ANOVA and the results showed no significant difference between the groups T/90min and T/120min and the groups T/60 and control (p>0.05). However, the differences between the groups T/120min and T/60min (p<0.001) and groups T/120min and T/90min (p<0.01) was significant. Conclusion: The study showed that ischemia-reperfusion time can be effective on apoptotic changes of myocardium cells of heart.


2008 ◽  
Vol 77 (2) ◽  
pp. 225-229 ◽  
Author(s):  
M. Fenyő ◽  
G. Szita ◽  
J. Bartyik ◽  
J. Dóra ◽  
S. Bernáth

Treatment with linearly polarized light (LPL) is a widely used and recognized therapeutic method in human medicine for healing wounds, ulcers and a variety of other dermatological problems. Polarized light mobilizes the inadequately functioning defence mechanisms of the human body. The aim of the present experiment was to investigate the effect of LPL treatment on the udder of milking cows. Before the start of treatment, there was no significant difference between cows to be treated with LPL and the control cows in mean somatic cell counts (SCC) of milk samples taken separately by udder quarter and in the mean milk yield. The LPL treatment lasted for 20 min and was performed twice a day over a period of one month. Before treatment, the mean SCC of milk was 3.47 × 105 ± 910 in the group to be treated and 4.07 × 105 ± 920 in the control group. In a six-week period immediately after treatment, the mean SCC of the treated and the control group was 1.32 × 105 ± 825 and 2.63 × 105 ± 825, indicating a significant difference in favour of the treated group. Before the LPL treatment, the milk yield of cows in the group to be treated was 25.77 ± 1.2 kg/ day, while that of the control cows was 27.30 ± 1.4 kg/day. In a six-week period after treatment, the milk yield of cows in the treated and control groups was 28.83 ± 1.5 kg/day and 25.48 ± 1.4 kg/day, respectively. There is a significant difference between these values in favour of the treated group. The results show that a regular LPL treatment of the udder of cows can significantly reduce the SCC of milk and significantly increase the milk yield. The treatment can be applied during lactation without interfering with the milking regime.


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