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1.
Biomolecules ; 14(3)2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38540706

RESUMO

Death is a multifaceted process wherein each individual cell and tissue has a metabolic homeostasis and a time of functional cessation defined by the dying process as well as by intrinsic and extrinsic factors. Decomposition is physiologically associated with the release of different types of volatile organic compounds (VOCs), and these form volaboloma mortis. The main purpose of this study was to record the volabolomic fingerprint produced by volatile molecules during the physiological decomposition process of human tissue and muscle cells. The volatile chemical signature has important implications for an open issue in forensics and pathology, namely the estimation of the postmortem interval (PMI), which decreases in accuracy with the passage of time. Volatile metabolites emitted from human tissues and muscle cells at 0, 24, 48, and 72 h were recorded in real time with an electronic nose sensor device. The key findings were the continuous sampling of VOCs emitted from tissues and cells. These showed a common behavior as time progressed; particularly, after 48 h the distributions became dispersed, and after 72 h they became more variable. Volabolomic fingerprinting associated with time progression relevant to the study of PMIs was reconstructed. Additionally, there may be broader applications, such as in dog training procedures for detecting human remains, and perhaps even for studying scavenger and insect attractants.


Assuntos
Mudanças Depois da Morte , Humanos , Animais , Cães , Autopsia
2.
Eur J Transl Myol ; 34(1)2024 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-38526419

RESUMO

Scientific conferences increasingly suffer from the need for short presentations in which speakers like to dwell on the details of their work. A mitigating factor is to encourage discussion and planning of collaborations by organizing small meetings in a hotel large enough to host all attendees. This extends discussions' opportunities during morning breakfasts, lunches, dinners and long evenings together. Even if the vast majority of participants will not stay for the entire duration of the Conference, the possibilities for specialists to interact with specialists who are even very distant in terms of knowledge increase enormously. In any case, the results in terms of new job opportunities for young participants outweigh the costs for the organizers. Thirty years of Padova Muscle Days offer many examples, but the authors of this report on the state of the art of Mobility Medicine testify that this also happened in the 2024 Five Days of Muscle and Mobility Medicine (2024Pdm3) hosted at the Hotel Petrarca, Thermae of Euganea Hills and Padua, Italy which is in fact a valid countermeasure to the inevitable tendencies towards hyperspecialization that the explosive increase in scientific progress brings with it.

3.
Acta Physiol (Oxf) ; 240(4): e14122, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38483046

RESUMO

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a demanding medical condition for patients and society. It has raised much more public awareness after the COVID-19 pandemic since ME/CFS and long-COVID patients share many clinical symptoms such as debilitating chronic fatigue. However, unlike long COVID, the etiopathology of ME/CFS remains a mystery despite several decades' research. This review moves from pathophysiology of ME/CFS through the compelling evidence and most interesting hypotheses. It focuses on the pathophysiology of skeletal muscle by proposing the hypothesis that skeletal muscle tissue offers novel opportunities for diagnosis and treatment of this syndrome and that new evidence can help resolve the long-standing debate on terminology.


Assuntos
Síndrome de Fadiga Crônica , Humanos , Síndrome de Fadiga Crônica/diagnóstico , Síndrome de Fadiga Crônica/epidemiologia , Síndrome Pós-COVID-19 Aguda , Pandemias , Músculo Esquelético/metabolismo
4.
Artigo em Inglês | MEDLINE | ID: mdl-38320257

RESUMO

Exposure to high altitude might cause the body to adapt with negative energy and fluid balance that compromise body composition and physical performance. In this field study involving 12 healthy adults, sex-balanced, and aged 29 ± 4 years with a body mass index of 21.6 ± 1.8 kg/m2, we investigated the effects of a 4-day trekking up to 4556 m a.s.l. on Monte Rosa (Alps, Italy). The food intake was recorded using food diaries and nutrient averages were calculated. The bio-impedance analysis was performed at low and high altitudes, and a wearable biosensor (Swemax) was used to track hydro-saline losses in two participants. Daily total energy intake was 3348 ± 386 kcal for males and 2804 ± 415 kcal for females (13%-14% protein, 35% fat, 44%-46% carbohydrates). Although there was a significant body weight loss (65.0 ± 9.3 vs. 64.2 ± 9.10 kg, p < 0.001, d = 1.398), no significant changes in body composition parameter were found but a trend in the increase of the bioelectrical phase angle in males (p = 0.059, d = -0.991). Body water percentage significantly changed (p = 0.026, η2 p = 0.440), but the absolute water did not, suggesting that the weight loss was not due to water loss. Salivary and urinary osmolality did not change. A reduction in sweat rate at higher altitudes was observed in both participants. Interestingly, salivary leptin increased (p = 0.014, η2 p = 0.510), and salivary ghrelin decreased (p = 0.036, η2 p  = 0.403). Therefore, the 4-day trekking at altitude of hypoxia exposure induced changes in satiety and appetite hormones. High altitude expeditions require more specific nutritional guidance, and using multiplex analysis could help in monitoring fluid balance and body composition.

5.
Mol Genet Metab ; 140(3): 107705, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37837864

RESUMO

PURPOSE: Beyond classical procedures, bioinformatic-assisted approaches and computational biology offer unprecedented opportunities for scholars. However, these amazing possibilities still need epistemological criticism, as well as standardized procedures. Especially those topics with a huge body of data may benefit from data science (DS)-assisted methods. Therefore, the current study dealt with the combined expert-assisted and DS-assisted approaches to address the broad field of muscle secretome. We aimed to apply DS tools to fix the literature research, suggest investigation targets with a data-driven approach, predict possible scenarios, and define a workflow. METHODS: Recognized scholars with expertise on myokines were invited to provide a list of the most important myokines. GeneRecommender, GeneMANIA, HumanNet, and STRING were selected as DS tools. Networks were built on STRING and GeneMANIA. The outcomes of DS tools included the top 5 recommendations. Each expert-led discussion has been then integrated with an DS-led approach to provide further perspectives. RESULTS: Among the results, 11 molecules had already been described as bona-fide myokines in literature, and 11 molecules were putative myokines. Most of the myokines and the putative myokines recommended by the DS tools were described as present in the cargo of extracellular vesicles. CONCLUSIONS: Including both supervised and unsupervised learning methods, as well as encompassing algorithms focused on both protein interaction and gene represent a comprehensive approach to tackle complex biomedical topics. DS-assisted methods for reviewing existent evidence, recommending targets of interest, and predicting original scenarios are worth exploring as in silico recommendations to be integrated with experts' ideas for optimizing molecular studies.


Assuntos
Músculo Esquelético , Secretoma , Humanos , Músculo Esquelético/metabolismo , Exercício Físico/fisiologia , Biologia Computacional/métodos
6.
Eur J Transl Myol ; 33(3)2023 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-37700736

RESUMO

Reports of electromyography during hypoxic exercise are contrasting, due to protocol and muscle diversity. This work aimed to investigate alterations in muscle activation and myoelectrical fatigue during exercise at high-altitude in those muscles primarily involved in trekking. Twelve young adults balanced by gender and age were tested at low (1,667 m) and high (4,554 m, "Capanna Margherita", Italy) altitude, during an isometric squat lasting 60 seconds. High-density surface electromyography was performed from the quadriceps of right limb. The root mean square (RMS), median frequency with its slope, and muscle fiber conduction velocity (MFCV) were computed. Neither males nor females showed changes in median frequency (Med: 36.13 vs 35.63 Hz) and its slope (Med: -9 vs -12 degree) in response to high-altitude trekking, despite a great inter-individual heterogeneity, nor differences were found for MFCV. RMS was not significantly equivalent, with greater values at low altitude (0.385 ± 0.104 mV) than high altitude (0.346 ± 0.090 mV). Unexpected results can be due either to a postural compensation of the whole body compensating for a relatively greater effort or to the inability to support muscle activation after repeated physical efforts.  Interesting results may emerge by measuring simultaneously electromyography, muscle oxygenation and kinematics comparing trekking at normoxia vs hypoxia.

7.
RSC Adv ; 13(31): 21277-21282, 2023 Jul 12.
Artigo em Inglês | MEDLINE | ID: mdl-37456547

RESUMO

This paper presents the analytical derivation of spreading resistance expressions for diverse geometries of a conducting probe submerged in a lossy medium. Resulting equations can be used to calibrate scanning impedance/scanning microwave microscopes operating in liquid. The expressions are systematically validated through numerical and experimental methods for the calibration of an inverted Scanning Microwave Microscope (iSMM) when operating in a lossy saline medium, such as Dulbecco's Modified Eagle Medium (DMEM), a widely used medium for supporting the growth of biological cells. The calibration process within DMEM plays an important role in the quantitative local evaluation of electromagnetic properties of biological samples under physiological conditions. Additionally, measurements are performed in distilled water for comparative analysis.

8.
Pflugers Arch ; 475(6): 691-709, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37156970

RESUMO

Extracellular vesicles (EVs) enriched with bioactive molecules have gained considerable attention in nanotechnology because they are critical to intercellular communication while maintaining low immunological impact. Among biological matrices, urine has emerged as a noninvasive source of extracellular-contained liquid biopsy, currently of interest as a readout for physiological adaptations. Therefore, we aimed to evaluate chronic adaptations of endurance sport practice in terms of urinary EV parameters and evaluated by food consumption assessment. Two balanced groups of 13 inactive controls vs. triathlon athletes were enrolled; their urinary EVs were obtained by differential ultracentrifugation and analyzed by dynamic light scattering and transmission electron and atomic force microscopy. The cargo was analyzed by means of purine and miRNA content through HPLC-UV and qRT-PCR. Specific urinary EV signatures differentiated inactive versus endurance-trained in terms of peculiar shape. Particularly, a spheroid shape, smaller size, and lower roughness characterize EVs from triathletes. Metabolic and regulatory miRNAs often associated with skeletal muscle (i.e., miR378a-5p, miR27a-3p, miR133a, and miR206) also accounted for a differential signature. These miRNAs and guanosine in urinary EVs can be used as a readout for metabolic status along with the shape and roughness of EVs, novel informative parameters that are rarely considered. The network models allow scholars to entangle nutritional and exercise factors related to EVs' miRNA and purine content to depict metabolic signatures. All in all, multiplex biophysical and molecular analyses of urinary EVs may serve as promising prospects for research in exercise physiology.


Assuntos
Líquidos Corporais , Vesículas Extracelulares , MicroRNAs , Sistema Urinário , Humanos , MicroRNAs/metabolismo , Sistema Urinário/metabolismo , Vesículas Extracelulares/metabolismo , Líquidos Corporais/metabolismo , Purinas/metabolismo
9.
Sensors (Basel) ; 23(9)2023 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-37177559

RESUMO

Many skeletal muscle diseases such as muscular dystrophy, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and sarcopenia share the dysregulation of calcium (Ca2+) as a key mechanism of disease at a cellular level. Cytosolic concentrations of Ca2+ can signal dysregulation in organelles including the mitochondria, nucleus, and sarcoplasmic reticulum in skeletal muscle. In this work, a treatment is applied to mimic the Ca2+ increase associated with these atrophy-related disease states, and broadband impedance measurements are taken for single cells with and without this treatment using a microfluidic device. The resulting impedance measurements are fitted using a single-shell circuit simulation to show calculated electrical dielectric property contributions based on these Ca2+ changes. From this, similar distributions were seen in the Ca2+ from fluorescence measurements and the distribution of the S-parameter at a single frequency, identifying Ca2+ as the main contributor to the electrical differences being identified. Extracted dielectric parameters also showed different distribution patterns between the untreated and ionomycin-treated groups; however, the overall electrical parameters suggest the impact of Ca2+-induced changes at a wider range of frequencies.


Assuntos
Fibras Musculares Esqueléticas , Músculo Esquelético , Ionomicina/farmacologia , Ionomicina/metabolismo , Músculo Esquelético/fisiologia , Linhagem Celular , Análise Espectral , Cálcio/metabolismo
10.
Cranio ; 41(6): 556-564, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33554766

RESUMO

OBJECTIVE: Occlusal disturbances affect human posture and sports performance. This study aimed to monitor biomechanical adaptations to personalized occlusal splints. METHODS: Splints were customized based on stabilometry, thermography, sEMG, and kinesiography, and administered to three triathlon athletes. They were evaluated during a 4-month period, using isokinetic indexes, running kinematics and anaerobic outputs. RESULTS: Individuality emerged as a key factor driving type, quantity, quality, and time trajectories of adaptations. The use of instrumental and clinical tests allowed the detection of static balance and biting function improvements, but not necessarily parallel to sports performance improvements. CONCLUSION: The authors argue that strength and kinematic imbalances are joint and task-specific and support the use of multi-stage monitoring of the biomechanical effect of mouthpieces. Kinematics of cycling and running may be widely assessed with ecological and inexpensive methods. Strength imbalances need to be continuously monitored due to the high informative value to injury prevention.


Assuntos
Desempenho Atlético , Corrida , Humanos , Placas Oclusais , Contenções , Atletas
11.
Int J Mol Sci ; 23(16)2022 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-36012330

RESUMO

Many authors described negative but reversible effects of high-altitude hypoxic exposure on animal and human fertility in terms of sperm concentration, function, and biochemical alterations. The aim of this study was to evaluate the acute and chronic effects of high-altitude exposure on classical sperm parameters, redox status, and membrane composition in a group of travellers. Five healthy Italian males, all lowlanders not accustomed to the altitude, were evaluated after 19 days-trekking through low, moderate, and high altitudes in the Himalayas. Sperm samples were collected before (Pre), 10 days after (Post), and 70 days after the end of the expedition (Follow-up). Sperm concentration, cholesterol and oxysterol membrane content, and redox status were measured. Hypoxic trek led to a significant reduction in sperm concentration (p < 0.001, η2p = 0.91), with a reduction from Pre to Post (71.33 ± 38.81 to 60.65 ± 34.63 × 106/mL) and a further reduction at Follow-up (to 37.13 ± 39.17 × 106/mL). The seminal volume was significantly affected by the hypoxic trek (p = 0.001, η2p = 0.75) with a significant reduction from Pre to Post (2.86 ± 0.75 to 1.68 ± 0.49 mL) and with partial recovery at Follow-up (to 2.46 ± 0.45 mL). Moreover, subjects had an increase in ROS production (+86%), and a decrease in antioxidant capacity (−37%) in the Post period with partial recovery at Follow-up. These results integrated the hormonal response on thyroid function, hypothalamus−pituitary−gonadal axis, and the prolactin/cortisol pathways previously reported. An uncontrolled ROS production, rather than a compromised antioxidant activity, was likely the cause of impaired sperm quality. The reduction in fertility status observed in this study may lie in an evolutionary Darwinian explanation, i.e., limiting reproduction due to the "adaptive disadvantage" offered by the combined stressors of high-altitude hypoxia and daily physical exercise.


Assuntos
Altitude , Sêmen , Antioxidantes/metabolismo , Fertilidade , Humanos , Hipóxia , Masculino , Oxirredução , Espécies Reativas de Oxigênio , Sêmen/metabolismo
12.
Neuropsychobiology ; 81(4): 322-332, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35753309

RESUMO

INTRODUCTION: Since decades, the "Mozart effect" has been studied. However, the diverse effects of Mozart's music components have not been yet defined. Authors aimed to identify a differential response to short-term exposure to Mozart's music, or to its rhythmic signature only, on subjective and objective measures. METHODS: The Mozart Sonata in A major K 331 (Mozart), the same piece consisting only of beat (Destructured), and duration-matched silence were administered to 25 healthy young adults, stood supine in a relaxing setting. The Italian Mood Scale questionnaire was administered before and after each listening. Heart rate variability (HRV) metrics were calculated from ECG recording, and breath flow was registered during experiments. RESULTS: After Destructured, there was no change of fatigue and tension. After Mozart, fatigue was significantly reduced (and a tendency appeared for tension), whereas vigor was not. Breathing rate tended to be higher during Mozart. The nonlinear parameter HFD of HRV analysis, even though not significantly, was slightly lower during Destructured; Poincaré plots SD1 and SD2 tended to be lower during Mozart. DISCUSSION/CONCLUSION: Mozart's music may allow to maintain arousal during relaxing condition. Psychological response of music and physiological dynamics were not necessarily entangled. Musical pieces based on individual physiological signature may lead musical psychological interventions.


Assuntos
Música , Estimulação Acústica , Nível de Alerta , Percepção Auditiva/fisiologia , Fadiga , Humanos , Música/psicologia , Adulto Jovem
13.
Front Physiol ; 13: 886149, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35694403

RESUMO

Human postmortem skeletal muscles are a unique source of satellite cells for skeletal muscle regenerative studies. Presomite and somite satellite cells obtained by postmortem muscles have been established as populations of human skeletal muscle precursor cells able to proliferate and differentiate in vitro. It is extremely interesting to have access to a large amount of postmortem human skeletal muscle precursor cells, especially from craniofacial as well as limb skeletal muscles in order to evaluate their potential application not only for the fundamental understanding of muscle physiology and diseases but also for drug testing in a challenging 3D-shaping muscles like skeletal muscle microphysiological systems.

14.
Am J Hum Biol ; 34(8): e23758, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35613316

RESUMO

OBJECTIVES: We investigated the relationships between fine motor skills, fitness, anthropometrics, gender and perceived motor performance in school beginners. The aim of our study was to delineate whether and to what extent fine motor control would show meaningful synchrony with other motor variables in the age of onset of handwriting in school. METHODS: A sample of N = 239 of 6-to-8-year-old children were tested with an array of tasks measuring fine motor (i.e., dexterity and speed) and grapho-motor performance (tracing on a tablet screen), anthropometric indexes, and fitness (shuttle run) measures. A subset of 95 children was also tested for perceived motor competence. RESULTS: In spite of an overall poor anthropometric condition, our participants were relatively fit. As expected, older children performed better in both, fine motor tasks and the shuttle test. The girls were better in fine motor skills, and an original speed-quality trade-off in the drawing was found. However, the magnitude of difference by grade was greater for boys' fine motor skills than those of girls'. A network analysis revealed three specific clusters, (1) perceived competencies, (2) fitness, and (3) fine motor skills. CONCLUSIONS: Given the relative independence of these areas of physical performance, we suggest focusing on these three clusters as distinct areas of physical education. Fine motor skills deserve further consideration, especially at an early school age. We have demonstrated that network analysis and technology devices used to evaluate motor development are useful and meaningful tools.


Assuntos
Exercício Físico , Destreza Motora , Adolescente , Criança , Feminino , Humanos , Masculino , Instituições Acadêmicas
15.
High Alt Med Biol ; 23(1): 57-68, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35104160

RESUMO

Committeri Giorgia, Danilo Bondi, Carlo Sestieri, Ginevra Di Matteo, Claudia Piervincenzi, Christian Doria, Roberto Ruffini, Antonello Baldassarre, Tiziana Pietrangelo, Rosamaria Sepe, Riccardo Navarra, Piero Chiacchiaretta, Antonio Ferretti, and Vittore Verratti. Neuropsychological and neuroimaging correlates of high-altitude hypoxia trekking during the "Gokyo Khumbu/Ama Dablam" expedition. High Alt Med Biol. 23:57-68, 2022. Background: Altitude hypoxia exposure may produce cognitive detrimental adaptations and damage to the brain. We aimed at investigating the effects of trekking and hypoxia on neuropsychological and neuroimaging measures. Methods: We recruited two balanced groups of healthy adults, trekkers (n = 12, 6 F and 6 M, trekking in altitude hypoxia) and controls (gender- and age-matched), who were tested before (baseline), during (5,000 m, after 9 days of trekking), and after the expedition for state anxiety, depression, verbal fluency, verbal short-term memory, and working memory. Personality and trait anxiety were also assessed at a baseline level. Neuroimaging measures of cerebral perfusion (arterial spin labeling), white-matter microstructural integrity (diffusion tensor imaging), and resting-state functional connectivity (functional magnetic resonance imaging) were assessed before and after the expedition in the group of trekkers. Results: At baseline, the trekkers showed lower trait anxiety (p = 0.003) and conscientiousness (p = 0.03) than the control group. State anxiety was lower in the trekkers throughout the study (p < 0.001), and state anxiety and depression decreased at the end of the study in both groups (p = 0.043 and p = 0.007, respectively). Verbal fluency increased at the end of the study in both groups (p < 0.001), whereas verbal short-term memory and working memory performance did not change. No significant differences between before and after the expedition were found for neuroimaging measures. Conclusions: We argue that the observed differences in the neuropsychological measures mainly reflect aspecific familiarity and learning effects due to the repeated execution of the same questionnaires and task. The present results thus suggest that detrimental effects on neuropsychological and neuroimaging measures do not necessarily occur as a consequence of short-term exposure to altitude hypoxia up to 5,000 m, especially in the absence of altitude sickness.


Assuntos
Doença da Altitude , Expedições , Montanhismo , Adaptação Fisiológica , Adulto , Altitude , Doença da Altitude/diagnóstico por imagem , Imagem de Tensor de Difusão , Humanos , Hipóxia/diagnóstico por imagem
16.
J Clin Med ; 11(3)2022 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-35159999

RESUMO

The literature shows that low back pain causes a reduced lumbar range of movement, affecting patients' proprioception and motor control. Nevertheless, studies have found that proprioception and motor control of the spine and posture are vague and individually expressed even in healthy young adults. This study aimed to investigate the standing posture and its modifications induced by an instinctive self-correction manoeuvre in subacute and chronic nonspecific low back pain (NSLBP) patients to clarify how NSLBP relates to body upright posture, proprioception, and motor control and how these are modified in patients compared to healthy young adults (121 healthy young adults: 57 females and 64 males). A cohort of 83 NSLBP patients (43 females, 40 males) were recruited in a cross-sectional observational study. Patients' entire body posture, including 3D spine shape reconstruction, was measured using a non-ionising 3D optoelectronic stereophotogrammetric approach. Thirteen quantitative biomechanical parameters describing the nature of body posture were computed. The statistical analysis was performed using multivariate methods. NSLBP patients did not present an altered proprioception and motor control ability compared to healthy young adults. Furthermore, as for healthy subjects, NSLBP patients could not focus and control their posture globally. Proprioception and motor control in natural erect standing are vague for most people regardless of gender and concurrent nonspecific low back pain. Self-correction manoeuvres improving body posture and spine shape must be learned with specific postural training focusing on the lumbar spine.

17.
Antioxidants (Basel) ; 11(2)2022 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-35204250

RESUMO

High-altitude locations are fascinating for investigating biological and physiological responses in humans. In this work, we studied the high-altitude response in the plasma and urine of six healthy adult trekkers, who participated in a trek in Nepal that covered 300 km in 19 days along a route in the Kanchenjunga Mountain and up to a maximum altitude of 5140 m. Post-trek results showed an unbalance in redox status, with an upregulation of ROS (+19%), NOx (+28%), neopterin (+50%), and pro-inflammatory prostanoids, such as PGE2 (+120%) and 15-deoxy-delta12,14-PGJ2 (+233%). The isoprostane 15-F2t-IsoP was associated with low levels of TAC (-18%), amino-thiols, omega-3 PUFAs, and anti-inflammatory CYP450 EPA-derived mediators, such as DiHETEs. The deterioration of antioxidant systems paves the way to the overload of redox and inflammative markers, as triggered by the combined physical and hypoxic stressors. Our data underline the link between oxidative stress and inflammation, which is related to the concept of OxInflammation into the altitude hypoxia fashion.

19.
Anal Chim Acta ; 1173: 338678, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-34172152

RESUMO

Oxidative stress (OS) is one of the leading causes of cytotoxicity and is linked to many human physio-pathological conditions. In particular, myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) induced by OS is debilitating to quality of life, while no clear biological markers have been identified for diagnostic measures. Recently, impedance measurements of peripheral blood cells of ME/CFS patients have been shown as a promising approach to diagnose the disease. Inspired by this study and aiming to interrogate muscle cells directly, we investigated if broadband measurements of single muscle cells could differentiate normal and oxidatively stressed cell populations. We first optimized a protocol through H2O2 treatment to introduce oxidative stress to cultured rat L6 skeletal muscle cells. The treated cells were further characterized through broadband impedance spectroscopy of single cells using a microfluidic lab-on-a-chip system. The resulting dielectric properties of cytoplasm permittivity and conductivity are electrically distinct from normally cultured cells. The reflection and transmission coefficients, ΔS11 and ΔS21, of the normal cells are tightly clustered and closely resemble those of the cell-free solution across the frequency range of 9 kHz to 9 GHz. On the other hand, dielectric properties of the oxidized cells have a wide distribution in the GHz range, deviating both in the positive and negative directions from the normally cultured cells. Simulation results guide our hypothesis that the dielectric differences could be linked to ion alterations, while calcium imaging directly supports the contribution of calcium flux to the observed deviation of S parameters. The unique electrical profile associated with oxidized cells in the GHz frequencies provide a framework for future development of technologies to diagnose oxidative-stress related diseases such as ME/CFS.


Assuntos
Síndrome de Fadiga Crônica , Qualidade de Vida , Impedância Elétrica , Humanos , Músculo Esquelético , Estresse Oxidativo
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