Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 363
Filtrar
1.
Oncologist ; 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38776551

RESUMO

INTRODUCTION: Pathogenic mutations in POLE/POLD1 lead to decreased fidelity of DNA replication, resulting in a high tumor mutational burden (TMB-H), defined as TMB ≥ 10 mut/Mb, independent of deficient mismatch repair (dMMR) and microsatellite instability high (MSI-H) status. METHODS: De-identified records of patients with colorectal cancer (CRC) profiled with the Tempus xT assay (DNA-seq of 595-648 genes at 500×) were identified from the Tempus Database. RESULTS: Among 9136 CRC samples profiled, the frequency of POLE/POLD1 genomic alterations was 2.4% (n = 217). Copy number loss was the most common genomic alteration (64%, n = 138) of POLE/POLD1, followed by copy number amplifications (18%, n = 40) and short variant mutations (18%, n = 39). The POLE/POLD1 mutated group presented with a higher frequency of TMB-H phenotype relative to wild type (WT; 22% vs. 9%, P < .001), with a median TMB of 127 mut/Mb in the TMB-H POLE/POLD1 subset. The TMB showed a dramatic contrast between POLE/POLD1 short variant mutations as compared to the group with copy number alterations, with a TMB of 159 mut/Mb vs 15 mut/Mb, respectively. Thus, the short variant mutations represented the so-called ultra-hypermutated phenotype. The POLE/POLD1 mutated group, as compared to WT, exhibited a higher rate of coexisting mutations, including APC, ALK, ATM, BRCA2, and RET mutations. CONCLUSION: Patients with POLE/POLD1 mutations exhibited significant differences across immunological markers (ie, TMB, MMR, and MSI-H) and molecular co-alterations. Those with short variant mutations represented 18% of the POLE/POLD1 cohort and 0.4% of the total cohort examined. This group of patients had a median TMB of 159 mut/Mb (range 34-488), representing the ultra-hypermutated phenotype. This group of patients is important to identify given the potential for exceptional response to immune checkpoint inhibitors.

2.
Oncologist ; 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38478398

RESUMO

We present a 54-year-old White male with a diagnosis of stage IV pancreatic neuroendocrine carcinoma. Next-generation sequencing of the tumor/blood identified a complex tumor genome, which included a rearranged during transfection (RET) gene fusion. The patient initially received cytotoxic chemotherapy with a significant radiographic response. After 4 cycles of chemotherapy, the patient was transitioned to a clinical trial using selpercatinib, a RET inhibitor, as maintenance therapy. Unfortunately, our patient developed progression of disease at the first treatment monitoring scan. Our patient suffered primary resistance to RET-targeted therapy. Proposed mechanisms of resistance include intrinsic resistance of the nuclear receptor co-activator 4-RET fusion to RET inhibition, the RET fusion representing a passenger alteration to another tumorigenic driver pathway and/or decreased efficacy of RET inhibition after platinum-based chemotherapy. Our patient's clinical course highlights the fact that "actionable" genomic alterations do not always equate to patient benefit.

3.
Phys Chem Chem Phys ; 26(11): 8670-8680, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38437035

RESUMO

The reactions of Ta+ and Nb+ with CO2 proceed only by a highly efficient oxygen atom transfer reaction to the respective oxide at room temperature in the gas phase. Although the product spin states are not determined, thermochemistry dictates that they must be different from ground state quintet Ta+ and Nb+, implying that intersystem crossing (ISC) has occurred. Recent reactive scattering experiments found dominant indirect dynamics for the reaction with Ta+ hinting at a bottleneck along the reaction path. The question on the nature of the bottleneck, whether it involves a crossing point or a transition state, could not be finally answered because theory located both close to each other. Here, we aim at shedding further light onto the impact of intersystem crossing on the reaction dynamics and ultimately the reactivity of transition metal ion reactions in the gas phase. We employ a combination of thermal kinetics for Ta+ and Nb+ with CO2 using a selected-ion flow tube (SIFT) apparatus and differential scattering cross sections for Nb+ + CO2 from crossed-beam velocity map imaging. The reaction with niobium again shows dominant indirect dynamics and in general very similar dynamics compared to Ta+ + CO2. At thermal energies, both reactions show sub-collisional rate constants with small negative temperature dependencies. Experiments are complemented by high level quantum chemical calculations of the minimum energy pathway. Statistical modelling well-reproduces the experimental thermal rate constants, and suggests that the Nb+ reaction is rate-limited by the intersystem crossing at thermal energies.

4.
J Phys Chem A ; 128(2): 439-448, 2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38175962

RESUMO

Rate constants and product branching fractions were measured from 300-600 K for Fen- + O2 (n = 2-17) and for 300-500 K for FexNiy- + O2 (x + y = 3-9) using a selected-ion flow tube (SIFT) apparatus. Rate constants for 46 species are reported. All rate constants increased with increasing temperature, and several were in excess of the Langevin-Gioumousis-Stevenson (LGS) capture rate at elevated temperatures. As with previously studied transition metal anion oxidation reactions, the collision limit is treated as the sum of the LGS limit along with a hard-sphere contribution, allowing for determination of activation energies. These values are compared to each other along with previous results for Nin-. Measured rate constants for all three series (Fen-, Nin-, and FexNy-) vary over a relatively narrow range (1-5 × 10-10 cm3 s-1 at 300 K) being at least 15% of the collision rate constant. All reaction rate constants increase with temperature, described by small activation energies of 0.5-4 kJ mol-1. The data are consistent with an anticorrelation between the electron binding energy and rate constant, previously noted in other systems. The Fen- reaction produces a larger population of higher energy electrons than do the Nin- reactions, with FexNiy- producing an intermediate amount. The results suggest that the overall rate constant is limited by a small energetic barrier located at a large internuclear distance where electrostatic forces dominate, causing the potentials to be similar across systems, while the product formation is determined by the shorter-range, valence portion of the potential, which varies widely between systems.

5.
Phys Chem Chem Phys ; 25(35): 23477-23490, 2023 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-37646145

RESUMO

The electronic structure of a transition metal atom allows it to act as a catalytic active site by providing lower energy alternative pathways in chemical transformations. We have identified and kinetically characterized three such pathways in the title reaction. One is an adiabatic pathway that occurs on a single potential energy surface described within the Born-Oppenheimer approximation. A second pathway opens microseconds into the reaction as a portion of the reacting population competitively transitions from triplet to singlet multiplicity to circumvent energetic barriers on the triplet surface. These pathways are single- and two-state reactive (SSR and TSR) where the Co+ cation mediates an oxidative addition/reductive elimination sequence of the CH3CHO molecule. The third observed reaction pathway is the aldehyde hydrogen tunneling through an Eyring barrier to form high-spin products. First-order rate constants for the adiabatic and nonadiabatic energy lowered pathways, and the hydrogen tunneling pathway, are each measured using the single photon initiated dissociative rearrangement reaction (SPIDRR) experimental technique. We believe that this is the first experimental study where such disparate dynamic features (SSR, TSR, and H-tunneling) are disentangled in a system's chemistry, attributing specific rate constant values to each effect and quantifying the various competitions. Moreover, multi-reference CASSCF/CASPT2 calculations indicate that structures with covalent Co-H bonds are present exclusively along the excited singlet surface. This phenomenon significantly reduces these structures' energy relative to their triplet counterparts, thus enabling the surface crossing and spin inversion that cause the observed two-state reactivity.

6.
J Phys Chem A ; 127(34): 7221-7227, 2023 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-37584597

RESUMO

Rate constants and product branching fractions were measured for reactions of Ar+, O2+, and NO+ with isoprene (2-methyl-1,3-butadiene C5H8) as a function of temperature. The rate constants are large (∼2 × 10-9 cm3 s-1) and increase with temperature, exceeding the ion-dipole/induced dipole capture rate. Adding a hard sphere term to the collision rate provides a more useful upper limit and predicts the positive temperature dependences. Previous kinetic energy-dependent rate constants show a similar trend. NO+ reacts only by non-dissociative charge transfer. The more energetic O2+ reaction has products formed through both non-dissociative and dissociative charge transfer, or possibly through an H atom transfer. The very energetic Ar+ has essentially only dissociative products; assumption of statistical behavior in the dissociation reasonably reproduces the product branching fractions.

7.
J Chem Phys ; 159(4)2023 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-37486057

RESUMO

The rate constant for electron attachment to Mo(CO)6 was determined to be ka = 2.4 ± 0.6 × 10-7 cm3 s-1 at 297 K in a flowing-afterglow Langmuir-probe experiment. The sole anion product is Mo(CO)5-. A small decline in ka was observed up to 450 K, and decomposition was apparent at higher temperatures. The charge transfer reaction of Ar+ with Mo(CO)6 is exothermic by 7.59 ± 0.03 eV, which appears to be sufficient to remove the first 5 ligands from Mo(CO)6+.

8.
Cureus ; 15(4): e37428, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37181954

RESUMO

Background Detection of pathogenic germline variants (PGVs) has implications for cancer screening, prognosis, treatment selection, clinical trial enrollment, and family testing. Published guidelines provide indications for PGV testing, determined by clinical and demographic factors, but their applicability in an ethnically and racially diverse community hospital population is unknown. This study describes the diagnostic and incremental yield of universal multi-gene panel testing in a diverse population in a community cancer practice. Methods We completed a prospective study of proactive germline genetic sequencing among patients with solid tumor malignancies at a community-based oncology practice in downtown Jacksonville, FL, between June 2020 and September 2021. The patients were unselected for cancer type, stage, family history, race/ethnicity, and age. PGVs identified using an 84-gene next-generation sequencing (NGS) tumor genomic testing platform were stratified by penetrance. National Comprehensive Cancer Networks (NCCN) guidelines determined incremental PGV rates. Results Two hundred twenty-three patients were enrolled, with a median age of 63 years, 78.5% female. 32.7% were Black/African American, and 5.4% were Hispanic. 39.9% of patients were commercially insured, Medicare/Medicaid insured 52.5%, and 2.7% were uninsured. The most common cancers in this cohort were breast (61.9%), lung (10.3%), and colorectal (7.2%). Twenty-three patients (10.3%) carried one or more PGVs, and 50.2% carried a variant of uncertain significance (VUS). Though there was no significant difference in the rate of PGVs based on race/ethnicity, African Americans were numerically more likely to have a VUS reported than whites (P=0.059). Eighteen (8.1%) patients had incremental clinically actionable findings that practice guidelines would not have detected, which was higher in non-whites. Conclusions In this racially/ethnically and socioeconomically diverse cohort, universal multi-gene panel testing (MGPT) increased diagnostic yield over targeted guideline-informed testing. Rates of VUS and incremental PGV were higher in non-white populations.

9.
Cureus ; 15(4): e37239, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37168199

RESUMO

The role of circulating tumor DNA (ctDNA) is expanding in oncology practices, and it is increasingly being used for targeted therapies and disease monitoring. It is minimally invasive and provides data from both primary and secondary sites of disease. Herein, we report a unique case of a patient with microsatellite instability-high (MSI-H) pancreatic adenocarcinoma (PDAC) treated with neoadjuvant chemotherapy and pembrolizumab who achieved a pathologically confirmed complete resolution of the tumor. A 75-year-old female was diagnosed with pancreatic adenocarcinoma (PDAC) in the uncinate process with aortocaval and retrocrural adenopathy. Next-generation sequencing was obtained via ctDNA testing, and the patient was initiated on cytotoxic chemotherapy while awaiting results. ctDNA revealed MSI-H status, and pembrolizumab was added to the cytotoxic chemotherapy regimen. At follow-up after five cycles of treatment, excellent treatment response was noted on magnetic resonance imaging (MRI) of the abdomen, demonstrating the resolution of the pancreatic mass and adenopathy. Six months of neoadjuvant treatment was given in total, after which the patient underwent resection with curative intent and achieved a complete pathological response with no evidence of disease. The role of ctDNA testing in directing treatment and influencing follow-up has already demonstrated great value. In our case, ctDNA adequately replaced conventional tissue biopsy, alleviating the burden of invasive testing on the patient. This is of great value, especially for patients with non-resectable tumors as well as in several other clinical scenarios. Our case also contributes to the growing body of literature demonstrating the role of immune-directed therapy for MSI-H PDAC.

10.
Int J Exerc Sci ; 16(1): 1451-1460, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38288256

RESUMO

The muscle up (MU) is a variation of a common gymnastics movement that combines a pull up and a dip. It can be performed on a bar (BMU) or a set of rings (RMU). The difference in upper extremity muscle recruitment (MR) between BMU and RMU has not been evaluated. Therefore, the purpose of this study was to compare the MR of select muscles during BMU and RMU. Ten active males (27.6 ± 7.9 years) performed 5 repetitions of BMU and RMU in randomized order. Muscle recruitment of the upper (UT) and lower trapezius (LT), serratus anterior (SA), pectoralis major (PM), latissimus dorsi (LD), triceps brachii (TB), biceps brachii (BB), and forearm flexors (FF) was assessed using electromyography. A 2 × 2 ANOVA (ring vs bar, pull phase vs push phase) with repeated measures was performed for each muscle. Least significant differences post hoc tests were performed when a significant interaction effect occurred. The RMU significantly elicited more muscle activation in the UT (p = 0.007), BB (p = 0.001), and FF (p = 0.001) during the pull phase. The RMU also significantly elicited more muscle activation in the TB (p = 0.025) and BB (p = 0.001) during the push phase. These results suggest that the instability of the RMU primarily increases the required recruitment of the upper limbs but does not significantly change the recruitment of the shoulder stabilizers. Appropriate upper limb development is needed to perform the RMU and the BMU may be a better technique to learn first due to its lower difficulty.

11.
Int J Exerc Sci ; 16(1): 1461-1470, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38288258

RESUMO

Portable media armbands are commonly used among the physically active population. Their effect on muscle function has not been established. The purpose of this study was to determine if muscle activation of the biceps brachii is influenced by wearing a portable media armband during an elbow flexion exercise. Eighteen participants (11 males: age = 22.5 ± 2.1 years, height = 178.3 ± 5.2 cm, mass = 85.0 ± 6.5 kg; 7 females: age = 22.9 ± 2.5 years, height = 168.3 ± 5.7 cm, mass = 72.3 ± 12.2 kg) with no history of upper extremity injury volunteered for the study. Participants performed elbow flexion trials with a hand-held dumbbell with and without wearing a portable media armband. Dumbbell weight was determined by an 8-10 repetition maximum, and the condition was counterbalanced. The average concentric and eccentric phases for five trials for each condition were normalized to a maximum voluntary isometric contraction using electromyography. The independent variable was condition (with-PMAB and without-PMAB). The dependent variable was the muscle activation of the biceps brachii. Mean data for each condition were analyzed using separate paired-samples t-tests for the concentric and eccentric phases (p < 0.05). Statistical analysis revealed a significant difference for the concentric phase (t17 = 2.905; p = 0.010). The with-PMAB condition elicited greater muscle activation (72.57 ± 36.31%) compared to the without-PMAB (63.67 ± 26.2%), with a medium effect size (d = 0.69). There was no statistical difference for the eccentric phase (t17 = 1.964; p = 0.066), and a small effect size (d = 0.46). The increase in muscle activation during the concentric phase is likely due to a change in the muscle properties due to the compressive force applied to the muscle fibers by the portable media armband.

12.
Med Educ Online ; 27(1): 2070940, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35506997

RESUMO

PURPOSE: Caring for critically ill patients requires non-technical skills such as teamwork, communication, and task management. The Behaviorally Anchored Rating Scale (BARS) is a brief tool used to assess non-technical skills. The investigators determined inter- and intra-rater reliability of the BARS when used to assess medical students in simulated scenarios. METHOD: The investigators created simulation scenarios for medical students during their pediatric clerkship. Content experts reviewed video recordings of the simulations and assigned BARS scores for four performance components (Situational Awareness, Decision-Making, Communication, and Teamwork) for the leader and for the team as a whole. Krippendorff's alpha with ordinal difference was calculated to measure inter- and intra-rater reliability. RESULTS: Thirty medical students had recordings available for review. Inter- and intra-rater reliability for performance components were, respectively, Individual Situational Awareness (0.488, 0.638), Individual Decision-Making (0.529, 0.691), Individual Communication (0.347, 0.473), Individual Teamwork (0.414, 0.466), Team Situational Awareness (0.450, 0.593), Team Decision Making (0.423, 0.703), Team Communication (0.256, 0.517), and Team Teamwork (0.415, 0.490). CONCLUSIONS: The BARS demonstrated limited reliability when assessing medical students during their pediatric clerkship. Given the unique needs of this population, a modified or new objective scoring system for assessing non-technical skills may be needed for medical students.


Assuntos
Estudantes de Medicina , Criança , Competência Clínica , Tomada de Decisões , Humanos , Equipe de Assistência ao Paciente , Reprodutibilidade dos Testes
13.
Phys Chem Chem Phys ; 24(4): 2300-2308, 2022 Jan 26.
Artigo em Inglês | MEDLINE | ID: mdl-35015007

RESUMO

For several decades, the influence of Two State Reactivity (TSR) has been implicated in a host of reactions, but has lacked a stand-alone, definitive experimental kinetic signature identifying its occurrence. Here, we demonstrate that the measurement of a temporally dependent product branching ratio is indicative of spin inversion and is a kinetic signature of TSR. This is caused by products exiting different hypersurfaces with different rates and relative exothermicities. The composite measurement of product intensities with the same mass but with different multiplicities yield biexponential temporal dependences with the sampled product ratio changing in time. These measurements are made using the single photon initiated dissociative rearrangement reaction (SPIDRR) technique which identifies TSR but further determines the kinetic parameters for reaction along the original ground electronic surface in competition with spin inversion and its consequent TSR.

15.
J Clin Transl Sci ; 3(1): 5-11, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31404158

RESUMO

Technological advancements in medical devices developed for adults far outpace the development of technologies designed for pediatric patients in the USA and other countries. This technology lag was previously reflected in a lack of pediatric-specific innovation within our academic institution. To address the institutional deficit of device innovation around pediatric patients, we formed unique partnerships both within our university and extending to the medical device industry, and developed novel programmatic approaches. The Pediatric Device Innovation Consortium (PDIC) bridges the medical device community and the University of Minnesota. Since 2014, the PDIC has supported 22 pediatric medical technology innovation projects, provided funds totaling more than $500,000, licensed two technologies, and advanced two technologies to patient use. Here, we describe the PDIC model and method, the PDIC approach to common challenges that arise in the development of small-market medical technologies at an academic institution, and iterations to our collaborative, multidisciplinary approach that have matured throughout our experience. The PDIC model continues to evolve to reflect the special needs of innovation for smaller markets and the unique role of clinician innovators. Our approach serves as a successful model for other institutions interested in creating support mechanisms for pediatric or small-market technology development.

16.
J Chem Phys ; 151(3): 034702, 2019 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-31325927

RESUMO

In this work, we examine metal electrode-ionomer electrolyte systems at high voltage (negative surface charge) and at high pH to assess factors that influence hydrogen production efficiency. We simulate the hydrogen evolution electrode interface investigated experimentally in the work of Bates et al. [J. Phys. Chem. C 119, 5467 (2015)] using a combination of first principles calculations and classical molecular dynamics. With this detailed molecular information, we explore the hypotheses posed in the work of Bates et al. In particular, we examine the response of the system to increased bias voltage and oxide coverage in terms of the potential profile, changes in solvation and species concentrations away from the electrode, surface concentrations, and orientation of water at reactive surface sites. We discuss this response in the context of hydrogen production.

17.
Prehosp Emerg Care ; 22(5): 630-636, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29452031

RESUMO

OBJECTIVE: This study aims to evaluate the efficacy of two different spinal immobilization techniques on cervical spine movement in a simulated prehospital ground transport setting. METHODS: A counterbalanced crossover design was used to evaluate two different spinal immobilization techniques in a standardized environment. Twenty healthy male volunteers (age = 20.9 ± 2.2 yr) underwent ambulance transport from a simulated scene to a simulated emergency department setting in two separate conditions: utilizing traditional spinal immobilization (TSI) and spinal motion restriction (SMR). During both transport scenarios, participants underwent the same simulated scenario. The main outcome measures were cervical spine motion (cumulative integrated motion and peak range of motion), vital signs (heart rate, blood pressure, oxygen saturation), and self-reported pain. Vital signs and pain were collected at six consistent points throughout each scenario. RESULTS: Participants experienced greater transverse plane cumulative integrated motion during TSI compared to SMR (F1,57 = 4.05; P = 0.049), and greater transverse peak range of motion during participant loading/unloading in TSI condition compared to SMR (F1,57 = 17.32; P < 0.001). Pain was reported by 40% of our participants during TSI compared to 25% of participants during SMR (χ2 = 1.29; P = 0.453). CONCLUSIONS: Spinal motion restriction controlled cervical motion at least as well as traditional spinal immobilization in a simulated prehospital ground transport setting. Given these results, along with well-documented potential complications of TSI in the literature, SMR is supported as an alternative to TSI. Future research should involve a true patient population.


Assuntos
Vértebras Cervicais/lesões , Imobilização/métodos , Traumatismos da Coluna Vertebral/terapia , Transporte de Pacientes/métodos , Adulto , Vértebras Cervicais/fisiopatologia , Estudos Cross-Over , Serviços Médicos de Emergência , Humanos , Imobilização/efeitos adversos , Masculino , Simulação de Paciente , Amplitude de Movimento Articular/fisiologia , Traumatismos da Coluna Vertebral/fisiopatologia , Adulto Jovem
18.
AJNR Am J Neuroradiol ; 38(9): 1783-1788, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28705815

RESUMO

BACKGROUND AND PURPOSE: Pulsatile tinnitus is experienced by most patients with idiopathic intracranial hypertension. The pathophysiology remains uncertain; however, transverse sinus stenosis and sigmoid sinus diverticulum/dehiscence have been proposed as potential etiologies. We aimed to determine whether the prevalence of transverse sinus stenosis and sigmoid sinus diverticulum/dehiscence was increased in patients with idiopathic intracranial hypertension and pulsatile tinnitus relative to those without pulsatile tinnitus and a control group. MATERIALS AND METHODS: CT vascular studies of patients with idiopathic intracranial hypertension with pulsatile tinnitus (n = 42), without pulsatile tinnitus (n = 37), and controls (n = 75) were independently reviewed for the presence of severe transverse sinus stenosis and sigmoid sinus diverticulum/dehiscence according to published criteria. The prevalence of transverse sinus stenosis and sigmoid sinus diverticulum/dehiscence in patients with idiopathic intracranial hypertension with pulsatile tinnitus was compared with that in the nonpulsatile tinnitus idiopathic intracranial hypertension group and the control group. Further comparisons included differing degrees of transverse sinus stenosis (50% and 75%), laterality of transverse sinus stenosis/sigmoid sinus diverticulum/dehiscence, and ipsilateral transverse sinus stenosis combined with sigmoid sinus diverticulum/dehiscence. RESULTS: Severe bilateral transverse sinus stenoses were more frequent in patients with idiopathic intracranial hypertension than in controls (P < .001), but there was no significant association between transverse sinus stenosis and pulsatile tinnitus within the idiopathic intracranial hypertension group. Sigmoid sinus dehiscence (right- or left-sided) was also more common in patients with idiopathic intracranial hypertension compared with controls (P = .01), but there was no significant association with pulsatile tinnitus within the idiopathic intracranial hypertension group. CONCLUSIONS: While our data corroborate previous studies demonstrating increased prevalence of sigmoid sinus diverticulum/dehiscence and transverse sinus stenosis in idiopathic intracranial hypertension, we did not establish an increased prevalence in patients with idiopathic intracranial hypertension with pulsatile tinnitus compared with those without. It is therefore unlikely that these entities represent a direct structural correlate of pulsatile tinnitus in patients with idiopathic intracranial hypertension.


Assuntos
Cavidades Cranianas/patologia , Pseudotumor Cerebral/complicações , Zumbido/etiologia , Idoso , Constrição Patológica/complicações , Constrição Patológica/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pseudotumor Cerebral/patologia
20.
J Strength Cond Res ; 31(9): 2363-2370, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28394829

RESUMO

Lyons, BC, Mayo, JJ, Tucker, WS, Wax, B, and Hendrix, RC. Electromyographical comparison of muscle activation patterns across 3 commonly performed kettlebell exercises. J Strength Cond Res 31(9): 2363-2370, 2017-The purpose of this study was to compare the muscle activation patterns of 3 different kettlebell (KB) exercises using electromyography (EMG). Fourteen resistance-trained subjects completed a 1-arm swing (Swing), 1-arm swing style snatch (Snatch), and a 1-arm clean (Clean) using a self-selected 8 to 10 repetition maximum load for each exercise. Trial sessions consisted of subjects performing 5 repetitions of each KB exercise. Mean EMG was used to assess the muscle activation of the biceps brachii, anterior deltoid, posterior deltoid, erector spinae (ES), vastus lateralis (VL), biceps femoris, contralateral external oblique (EO), and gluteus maximus during each lift using surface electrodes. The mean EMG was normalized using maximal voluntary contractions obtained from manual muscle testing. Repeated-measures analysis of variance revealed a significant difference in the muscle activation patterns of the ES (Swing > Snatch), EO (Snatch, Clean > Swing), and VL (Swing > Clean) across the 3 KB exercises. We conclude that although the KB Swing, Snatch, and Clean are total body exercises, they place different demands on the ES, contralateral EO, and the VL. Therefore, KBs represent an authentic alternative for lifters, and the Swing, Snatch, and Clean are not redundant exercises.


Assuntos
Músculo Esquelético/fisiologia , Treinamento Resistido/métodos , Músculos Abdominais Oblíquos/fisiopatologia , Adolescente , Braço/fisiologia , Eletromiografia , Exercício Físico/fisiologia , Humanos , Masculino , Músculos Paraespinais/fisiopatologia , Músculo Quadríceps/fisiologia , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...