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ABSTRACT: Estimating progression-free survival (PFS) and overall survival superiority during clinical trials of multiple myeloma (MM) has become increasingly challenging as novel therapeutics have improved patient outcomes. Thus, it is imperative to identify earlier end point surrogates that are predictive of long-term clinical benefit. Minimal residual disease (MRD)-negativity is a common intermediate end point that has shown prognostic value for clinical benefit in MM. This meta-analysis was based on the US Food and Drug Administration guidance for considerations for a meta-analysis of MRD as a clinical end point and evaluates MRD-negativity as an early end point reasonably likely to predict long-term clinical benefit. Eligible studies were phase 2 or 3 randomized controlled clinical trials measuring MRD-negativity as an end point in patients with MM, with follow-up of ≥6 months following an a priori-defined time point of 12 ± 3 months after randomization. Eight newly diagnosed MM studies evaluating 4907 patients were included. Trial-level associations between MRD-negativity and PFS were R2WLSiv, 0.67 (95% confidence interval [CI], 0.43-0.91) and R2copula 0.84 (0.64 to >0.99) at the 12-month time point. The individual-level association between 12-month MRD-negativity and PFS resulted in a global odds ratio (OR) of 4.02 (95% CI, 2.57-5.46). For relapse/refractory MM, there were 4 studies included, and the individual-level association between 12-month MRD-negativity and PFS resulted in a global OR of 7.67 (4.24-11.10). A clinical trial demonstrating a treatment effect on MRD is reasonably likely to eventually demonstrate a treatment effect on PFS, suggesting that MRD may be an early clinical end point reasonably likely to predict clinical benefit in MM, that may be used to support accelerated approval and thereby, expedite the availability of new drugs to patients with MM.
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Mieloma Múltiple , Neoplasia Residual , Neoplasia Residual/diagnóstico , Mieloma Múltiple/mortalidad , Mieloma Múltiple/diagnóstico , Mieloma Múltiple/tratamiento farmacológico , Mieloma Múltiple/terapia , Mieloma Múltiple/patología , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto , Supervivencia sin Progresión , PronósticoRESUMEN
Background: Advances in multiple myeloma (MM) treatment have shifted the therapeutic landscape. Understanding patients' perspectives can assist physicians in helping patients make informed decisions. This study aimed to understand the patient decision-making process and gain insights into patient perspectives on B-cell maturation antigen (BCMA)-targeted therapies for MM. Methods: An 18-question survey was completed by patients with MM enrolled in HealthTree® Cure Hub, an online portal helping patients with plasma cell dyscrasias navigate their disease. Results: From October 28, 2022, to January 12, 2023, 325 patients with MM participated in the survey. The mean age (standard deviation) of the respondents was 66 (8) years; 54% were female and 90% were White. Among 218 patients with complete clinical records in the database, the median (min, max) lines of therapy (LOT) was 2 (1,16). Among 61 (28%) patients who had received ≥4 LOTs, 55 (90%) were triple-class exposed. Of the 290 patients who responded to the question about openness to new therapies, 76 (26%) were open to trying a new therapy immediately and 125 (43%) wanted more information on safety and efficacy. Most respondents reported likely or very likely to try a BCMA CAR T-cell therapy (60%) or a bispecific antibody (74%) and some needed more information to decide (16% for CAR T-cell therapy and 13% for bispecific antibody). The most requested information included efficacy, side effects (SEs), eligibility, and administration process for both CAR T-cell and bispecific therapies. When 2 therapies with the same efficacy and duration of response were offered, 69% of respondents would prefer the therapy with a lower risk of severe SEs but requires continuous dosing with no treatment-free interval, and 31% preferred a therapy given once followed by a treatment-free interval but with a potentially higher risk of severe SEs. To receive an effective therapy, the top acceptable trade-offs included frequent monitoring of SEs and initiating a new therapy in a hospital setting, and the least acceptable compromise was caregiver burden. Conclusions: This study found a high level of openness in patients with MM to try BCMA-targeted therapies. Information on efficacy, safety, availability, and eligibility may assist patients on decision-making.
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NEW FINDINGS: What is the central question of this study? Use of the passive leg movement (PLM) test, a non-invasive assessment of microvascular function, is on the rise. However, PLM reliability in men has not been adequately investigated, nor has such reliability data, in men, been compared to the most commonly employed vascular function assessment, flow-mediated vasodilation (FMD). What is the main finding and its importance? PLM is a reliable method to assess vascular function in men, and is comparable to values previously reported for PLM in women, and for FMD. Given the importance of vascular function as a predictor of cardiovascular disease risk, these data support the utility of PLM as a clinically relevant measurement. ABSTRACT: Although vascular function is an independent predictor of cardiovascular disease risk, and therefore has significant prognostic value, there is currently not a single clinically accepted method of assessment. The passive leg movement (PLM) assessment predominantly reflects microvascular endothelium-dependent vasodilation and can identify decrements in vascular function with advancing age and pathology. Reliability of the PLM model was only recently determined in women, and has not been adequately investigated in men. Twenty healthy men (age: 27 ± 2 year) were studied on three separate experimental days, resulting in three within-day and three between-day trials. The hyperemic response to PLM was assessed with Doppler ultrasound, and expressed as the absolute peak in leg blood flow (LBFpeak ), change from baseline to peak (ΔLBFpeak ), absolute area under the curve (LBFAUC ), and change in AUC from baseline (ΔLBFAUC ). PLM-induced hyperemia yielded within-day coefficients of variation (CV) from 10.9 to 22.9%, intraclass correlation coefficients (ICC) from 0.82 to 0.90, standard error of the measurement (SEM) from 8.3 to 17.2%, and Pearson's correlation coefficients (r) from 0.56 to 0.81. Between-day assessments of PLM hyperemia resulted in CV from 14.4 to 25%, ICC from 0.75 to 0.87, SEM from 9.8 to 19.8%, and r from 0.46 to 0.75. Similar to previous reports in women, the hyperemic responses to PLM in men display moderate-to-high reliability, and are comparable to reliability data for brachial artery flow mediated vasodilation. These positive reliability findings further support the utility of PLM as a clinical measurement of vascular function and cardiovascular disease risk.
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Enfermedades Cardiovasculares , Hiperemia , Adulto , Arteria Braquial , Endotelio Vascular , Femenino , Humanos , Pierna/irrigación sanguínea , Masculino , Movimiento/fisiología , Flujo Sanguíneo Regional/fisiología , Reproducibilidad de los Resultados , Vasodilatación/fisiologíaRESUMEN
BACKGROUND: Bone remodeling is a lifelong process that ranges from orthodontic tooth movement/alignment to bone damage/healing, to overall bone health. Osteoprotegerin (OPG) and transforming growth factor ß1 (TGF-ß1) are secreted by osteoblasts and participate in bone remodeling. OPG promotes bone remineralization and stabilization prominent in post-mechanical repositioning of the teeth in the dental alveolus. TGF-ß1 participates in regulatory processes to promote osteoblast and osteoclast equilibrium. In the context of orthodontic tooth movement, post-treatment fixation requires additional, exogenous, stabilization support. Recent research showcases supplementary solutions, in conjunction to standard tooth fixation techniques, such as OPG injections into gum and periodontal tissues to accelerate tooth anchorage; however, injections are prone to post-procedure complications and discomfort. This study utilizes noninvasive bioelectric stimulation (BES) to modulate OPG and TGF-ß1 as a novel solution to regulate bone remineralization specifically in the context of post-orthodontic tooth movement. PURPOSE: The aim of this study was to investigate a spectrum of BES parameters that would modulate OPG and TGF-ß1 expression in osteoblasts. METHODS: Osteoblasts were cultured and stimulated using frequencies from 25 Hz to 3 MHz. RT-qPCR was used to quantify changes in OPG and TGFb-1 mRNA expression. RESULTS: OPG mRNA expression was significantly increased at frequencies above 10,000 Hz with a maximum expression increase of 332 ± 8% at 100 kHz. Conversely, OPG mRNA expression was downregulated at frequencies lower than 1000 Hz. TGF-ß1 mRNA expression increased throughout all stimulation frequencies with a peak of 332 ± 72% at 250 kHz. Alizarin Red tests for calcium, indicated that mineralization of stimulated osteoblasts in vitro increased 28% after 6 weeks in culture. DISCUSSION: Results support the working hypothesis that OPG and TGF-ß1 mRNA expression can be modulated through BES. Noninvasive BES approaches have the potential to accelerate bone remineralization by providing a novel tool to supplement the anchorage process, reduce complications, and promote patient compliance and reduce post-treatment relapse. Noninvasive BES may be applicable to other clinical applications as a novel therapeutic tool to modulate bone remodeling.
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Vascular function is further attenuated in patients with chronic heart failure implanted with a continuous-flow left ventricular assist device (LVAD), likely due to decreased arterial pulsatility, and this may contribute to LVAD-associated cardiovascular complications. However, the impact of increasing pulsatility on vascular function in this population is unknown. Therefore, 15 LVAD recipients and 15 well-matched controls underwent a 45-min, unilateral, arm pulsatility treatment, evoked by intermittent cuff inflation/deflation (2-s duty cycle), distal to the elbow. Vascular function was assessed by percent brachial artery flow-mediated dilation (%FMD) and reactive hyperemia (RH) (Doppler ultrasound). Pretreatment, %FMD (LVAD: 4.0 ± 1.7; controls: 4.2 ± 1.4%) and RH (LVAD: 340 ± 101; controls: 308 ± 94 mL) were not different between LVAD recipients and controls; however, %FMD/shear rate was attenuated (LVAD: 0.10 ± 0.04; controls: 0.17 ± 0.06%/s-1, P < 0.05). The LVAD recipients exhibited a significantly attenuated pulsatility index (PI) compared with controls prior to treatment (LVAD: 2 ± 2; controls: 15 ± 7 AU, P < 0.05); however, during the treatment, PI was no longer different (LVAD: 37 ± 38; controls: 36 ± 14 AU). Although time to peak dilation and RH were not altered by the pulsatility treatment, %FMD (LVAD: 7.0 ± 1.8; controls: 7.4 ± 2.6%) and %FMD/shear rate (LVAD: 0.19 ± 0.07; controls: 0.33 ± 0.15%/s-1) increased significantly in both groups, with, importantly, %FMD/shear rate in the LVAD recipients being restored to that of the controls pretreatment. This study documents that a localized pulsatility treatment in LVAD recipients and controls can recover local vascular function, an important precursor to the development of approaches to increase systemic pulsatility and reduce systemic vascular complications in LVAD recipients.
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Insuficiencia Cardíaca/terapia , Corazón Auxiliar , Implantación de Prótesis/instrumentación , Flujo Pulsátil , Oclusión Terapéutica/instrumentación , Extremidad Superior/irrigación sanguínea , Función Ventricular Izquierda , Anciano , Estudios de Casos y Controles , Estudios Cruzados , Insuficiencia Cardíaca/diagnóstico por imagen , Insuficiencia Cardíaca/fisiopatología , Humanos , Masculino , Persona de Mediana Edad , Diseño de Prótesis , Implantación de Prótesis/efectos adversos , Recuperación de la Función , Flujo Sanguíneo Regional , Oclusión Terapéutica/efectos adversos , Resultado del TratamientoRESUMEN
Passive leg movement (PLM) evokes a robust and predominantly nitric oxide (NO)-mediated increase in blood flow that declines with age and disease. Consequently, PLM is becoming increasingly accepted as a sensitive assessment of endothelium-mediated vascular function. However, a substantial PLM-induced hyperemic response is still evoked despite nitric oxide synthase (NOS) inhibition. Therefore, in nine young healthy men (25 ± 4 yr), this investigation aimed to determine whether the combination of two potent endothelium-dependent vasodilators, specifically prostaglandin (PG) and endothelium-derived hyperpolarizing factor (EDHF), account for the remaining hyperemic response to the two variants of PLM, PLM (60 movements) and single PLM (sPLM, 1 movement), when NOS is inhibited. The leg blood flow (LBF, Doppler ultrasound) response to PLM and sPLM following the intra-arterial infusion of NG-monomethyl-l-arginine (l-NMMA), to inhibit NOS, was compared to the combined inhibition of NOS, cyclooxygenase (COX), and cytochrome P-450 (CYP450) by l-NMMA, ketorolac tromethamine (KET), and fluconazole (FLUC), respectively. NOS inhibition attenuated the overall LBF [area under the curve (LBFAUC)] response to both PLM (control: 456 ± 194, l-NMMA: 168 ± 127 mL, P < 0.01) and sPLM (control: 185 ± 171, l-NMMA: 62 ± 31 mL, P = 0.03). The combined inhibition of NOS, COX, and CYP450 (i.e., l-NMMA+KET+FLUC) did not further attenuate the hyperemic responses to PLM (LBFAUC: 271 ± 97 mL, P > 0.05) or sPLM (LBFAUC: 72 ± 45 mL, P > 0.05). Therefore, PG and EDHF do not collectively contribute to the non-NOS-derived NO-mediated, endothelium-dependent hyperemic response to either PLM or sPLM in healthy young men. These findings add to the mounting evidence and understanding of the vasodilatory pathways assessed by the PLM and sPLM vascular function tests.NEW & NOTEWORTHY Passive leg movement (PLM) evokes a highly nitric oxide (NO)-mediated hyperemic response and may provide a novel evaluation of vascular function. The contributions of endothelium-dependent vasodilatory pathways, beyond NO and including prostaglandins and endothelium-derived hyperpolarizing factor, to the PLM-induced hyperemic response to PLM have not been evaluated. With intra-arterial drug infusion, the combined inhibition of nitric oxide synthase (NOS), cyclooxygenase, and cytochrome P-450 (CYP450) pathways did not further diminish the hyperemic response to PLM compared with NOS inhibition alone.
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Endotelio Vascular/fisiología , Hiperemia , Movimiento , Contracción Muscular , Músculo Esquelético/irrigación sanguínea , Óxido Nítrico/metabolismo , Vasodilatación , Adulto , Factores Biológicos/metabolismo , Velocidad del Flujo Sanguíneo , Inhibidores de la Ciclooxigenasa/administración & dosificación , Inhibidores Enzimáticos del Citocromo P-450/administración & dosificación , Endotelio Vascular/metabolismo , Voluntarios Sanos , Humanos , Infusiones Intraarteriales , Pierna , Masculino , Óxido Nítrico Sintasa/antagonistas & inhibidores , Óxido Nítrico Sintasa/metabolismo , Prostaglandinas/metabolismo , Flujo Sanguíneo Regional , Transducción de Señal , Factores de Tiempo , Adulto JovenRESUMEN
Nitric oxide synthase (NOS) inhibition with N(G)-monomethyl-l-arginine (L-NMMA) is often used to assess the role of NO in human cardiovascular function. However, the window of effect for L-NMMA on human vascular function is unknown, which is critical for designing and interpreting human-based studies. This study utilized the passive leg movement (PLM) assessment of vascular function, which is predominantly NO-mediated, in 7 young male subjects under control conditions, immediately following intra-arterial L-NMMA infusion (0.24 mgâ dl-1â min-1), and at 45-60 and 90-105 min post L-NMMA infusion. The leg blood flow (LBF) and leg vascular conductance (LVC) responses to PLM, measured with Doppler ultrasound and expressed as the change from baseline to peak (ΔLBFpeak and ΔLVCpeak) and area under the curve (LBFAUC and LVCACU), were assessed. PLM-induced robust control ΔLBFpeak (1135 ± 324 mlâ min-1) and ΔLVCpeak (10.7 ± 3.6 mlâ min-1â mmHg-1) responses that were significantly attenuated (704 ± 196 mlâ min-1 and 6.7 ± 2 mlâ min-1â mmHg-1) immediately following L-NMMA infusion. Likewise, control condition PLM ΔLBFAUC (455 ± 202 ml) and ΔLVCAUC (4.0 ± 1.4 mlâ mmHg-1) were significantly attenuated (141 ± 130 ml and 1.3 ± 1.2 mlâ mmHg-1) immediately following L-NMMA infusion. However, by 45-60 min post L-NMMA infusion all PLM variables were not significantly different from control, and this was still the case at 90-105 min post L-NMMA infusion. These findings reveal that the potent reduction in NO bioavailability afforded by NOS inhibition with L-NMMA has a window of effect of less than 45-60 min in the human vasculature. These data are particularly important for the commonly employed approach of pharmacologically inhibiting NOS with L-NMMA in the human vasculature.
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Inhibidores Enzimáticos/farmacocinética , Óxido Nítrico Sintasa/antagonistas & inhibidores , omega-N-Metilarginina/farmacocinética , Adulto , Arteria Femoral/fisiología , Hemodinámica/efectos de los fármacos , Humanos , Pierna/irrigación sanguínea , Masculino , Óxido Nítrico/metabolismo , Flujo Sanguíneo Regional/efectos de los fármacos , Factores de Tiempo , Adulto JovenRESUMEN
Cerebral blood flow (CBF) is commonly inferred from blood velocity measurements in the middle cerebral artery (MCA), using nonimaging, transcranial Doppler ultrasound (TCD). However, both blood velocity and vessel diameter are critical components required to accurately determine blood flow, and there is mounting evidence that the MCA is vasoactive. Therefore, the aim of this study was to employ imaging TCD (ITCD), utilizing color flow images and pulse wave velocity, as a novel approach to measure both MCA diameter and blood velocity to accurately quantify changes in MCA blood flow. ITCD was performed at rest in 13 healthy participants (7 men/6 women; 28 ± 5 yr) with pharmaceutically induced vasodilation [nitroglycerin (NTG), 0.8 mg] and without (CON). Measurements were taken for 2 min before and for 5 min following NTG or sham delivery (CON). There was more than a fivefold, significant, fall in MCA blood velocity in response to NTG (∆-4.95 ± 4.6 cm/s) compared to negligible fluctuation in CON (∆-0.88 ± 4.7 cm/s) (P < 0.001). MCA diameter increased significantly in response to NTG (∆0.09 ± 0.04 cm) compared with the basal variation in CON (∆0.00 ± 0.04 cm) (P = 0.018). Interestingly, the product of the NTG-induced fall in MCA blood velocity and increase in diameter was a significant increase in MCA blood flow following NTG (∆144 ± 159 ml/min) compared with CON (∆-5 ± 130 ml/min) (P = 0.005). These juxtaposed findings highlight the importance of measuring both MCA blood velocity and diameter when assessing CBF and document ITCD as a novel approach to achieve this goal.
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Circulación Cerebrovascular/fisiología , Arteria Cerebral Media/diagnóstico por imagen , Arteria Cerebral Media/fisiología , Ultrasonografía Doppler Transcraneal/métodos , Adulto , Circulación Cerebrovascular/efectos de los fármacos , Femenino , Voluntarios Sanos , Humanos , Masculino , Persona de Mediana Edad , Arteria Cerebral Media/efectos de los fármacos , Nitroglicerina/farmacología , Análisis de la Onda del Pulso , Ultrasonografía Doppler en Color , Vasodilatación/efectos de los fármacos , Vasodilatación/fisiología , Vasodilatadores/farmacología , Adulto JovenRESUMEN
Recognizing the age-related decline in skeletal muscle feed artery (SMFA) vasodilatory function, this study examined the link between vasodilatory and mitochondrial respiratory function in the human vasculature. Twenty-four SMFAs were harvested from young (35 ± 6 yr, n = 9) and old (71 ± 9 yr, n = 15) subjects. Vasodilation in SMFAs was assessed, by pressure myography, in response to flow-induced shear stress, acetylcholine (ACh), and sodium nitroprusside (SNP) while mitochondrial respiration was measured, by respirometry, in permeabilized SMFAs. Endothelium-dependent vasodilation was significantly attenuated in the old, induced by both flow (young: 92 ± 3, old: 45 ± 4%) and ACh (young: 92 ± 3, old: 54 ± 5%), with no significant difference in endothelium-independent vasodilation. Complex I and I + II state 3 respiration was significantly lower in the old (CI young: 10.1 ± 0.8, old: 7.0 ± 0.4 pmol·s-1·mg-1; CI + II young: 12.3 ± 0.6, old: 7.6 ± 0.4 pmol·s-1·mg-1). The respiratory control ratio (RCR) was also significantly attenuated in the old (young: 2.2 ± 0.1, old: 1.1 ± 0.1). Furthermore, state 3 (CI + II) and 4 respiration, as well as RCR, were significantly correlated (r = 0.49-0.86) with endothelium-dependent, but not endothelium-independent, function. Finally, the direct intervention with mitochondrial-targeted antioxidant (MitoQ) significantly improved endothelium-dependent vasodilation in the old but not in the young. Thus, the age-related decline in vasodilatory function is linked to attenuated vascular mitochondrial respiratory function, likely by augmented free radicals.NEW & NOTEWORTHY In human skeletal muscle feed arteries, the well-recognized age-related fall in endothelium-dependent vasodilatory function is strongly linked to a concomitant fall in vascular mitochondrial respiratory function. The direct intervention with the mitochondrial-targeted antioxidant restored vasodilatory function in the old but not in the young, supporting the concept that exacerbated mitochondrial-derived free radical production is linked to age-related vasodilatory dysfunction. Age-related vasodilatory dysfunction in humans is linked to attenuated vascular mitochondrial respiratory function, likely a consequence of augmented free radical production.
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Envejecimiento/fisiología , Radicales Libres/metabolismo , Mitocondrias/fisiología , Consumo de Oxígeno/fisiología , Vasodilatación/fisiología , Acetilcolina/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Antioxidantes/metabolismo , Humanos , Persona de Mediana EdadRESUMEN
Current continuous-flow left ventricular assist devices (LVADs) decrease peripheral vascular pulsatility, which may contribute to side effects such as bleeding and thrombotic events. However, the actual impact of manipulating LVAD pump speed, revolutions per minute (rpm), on peripheral (brachial) pulsatility index (brachial PI), in patients with heart failure implanted with a HeartWare (HVAD) or HeartMateII (HMII) LVAD is unknown. Therefore, blood velocities (Doppler ultrasound) in the brachial artery were recorded and brachial PI calculated across rpm manipulations which spanned the acceptable clinical outpatient range: 360 rpm (HVAD, n = 10) and 1200 rpm (HMII, n = 10). Left ventricular assist device-derived PIs were also recorded: HVAD maximal blood flow (HVADV max), HVAD minimum blood flow (HVADV min), and HMII PI (HMIIPI). Brachial PI changed significantly with rpm manipulations, from 2.3 ± 0.6 to 4.1 ± 0.8 (HVAD) and from 1.8 ± 0.5 to 3.6 ± 1.0 (HMII). Multilevel linear modeling with random intercepts revealed a 180 rpm decrease of the HVAD resulted in a 0.9 ± 0.1 (37 ± 4%, d = 2.65) increase in brachial PI and a 600 rpm decrease in the HMII resulted in a 0.8 ± 0.1 (38 ± 3%, d = 4.66) increase. Furthermore, a reduction in rpm resulted in a 20.0 ± 0.3% power savings, and a reduction in device reported blood flow of 9 ± 1%. Brachial PI was linearly related to HVADV max, HVADV min, their difference (R = 0.42, R = 0.65, and R = 0.54, respectively), and HMIIPI (R = 0.86). Manipulating LVAD pump speed, within a clinically acceptable outpatient range, resulted in a significant change in brachial PI, which was reflected by pump indices, documenting the potential for LVAD pump speed manipulations to improve LVAD outcomes.
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Insuficiencia Cardíaca/terapia , Corazón Auxiliar , Flujo Pulsátil/fisiología , Adulto , Anciano , Femenino , Insuficiencia Cardíaca/fisiopatología , Corazón Auxiliar/efectos adversos , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Early detection of coronary artery dysfunction is of paramount cardiovascular clinical importance, but a noninvasive assessment is lacking. Indeed, the brachial artery flow-mediated dilation test only weakly correlated with acetylcholine-induced coronary artery function ( r=0.36). However, brachial artery flow-mediated dilation methodologies have, over time, substantially improved. This study sought to determine if updates to this technique have improved the relationship with coronary artery function and the noninvasive indication of coronary artery dysfunction. Coronary artery and brachial artery function were assessed in 28 patients referred for cardiac catheterization (61±11 years). Coronary artery function was determined by the change in artery diameter with a 1.82 µg/min intracoronary acetylcholine infusion. Based on the change in vessel diameter, patients were characterized as having dysfunctional coronary arteries (>5% vasoconstriction) or relatively functional coronary arteries (<5% vasoconstriction). Brachial artery function was determined by flow-mediated dilation, adhering to current guidelines. The acetylcholine-induced change in vessel diameter was smaller in patients with dysfunctional compared with relatively functional coronary arteries (-11.8±4.6% versus 5.8±9.8%, P<0.001). Consistent with this, brachial artery flow-mediated dilation was attenuated in patients with dysfunctional compared with relatively functional coronaries (2.9±1.9% versus 6.2±4.2%, P=0.007). Brachial artery flow-mediated dilation was strongly correlated with the acetylcholine-induced change in coronary artery diameter ( r=0.77, P<0.0001) and was a strong indicator of coronary artery dysfunction (receiver operator characteristic=78%). The current data support that updates to the brachial artery flow-mediated dilation technique have strengthened the relationship with coronary artery function, which may now provide a clinically meaningful indication of coronary artery dysfunction.
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Acetilcolina/administración & dosificación , Arteria Braquial/efectos de los fármacos , Cateterismo Cardíaco/métodos , Enfermedad de la Arteria Coronaria/diagnóstico , Circulación Coronaria/efectos de los fármacos , Vasos Coronarios/efectos de los fármacos , Anciano , Arteria Braquial/fisiopatología , Estudios de Cohortes , Circulación Coronaria/fisiología , Vasos Coronarios/fisiopatología , Femenino , Humanos , Infusiones Intralesiones , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Estudios Prospectivos , Curva ROC , Medición de Riesgo , Vasoconstricción/efectos de los fármacos , Vasoconstricción/fisiología , Vasodilatación/efectos de los fármacos , Vasodilatación/fisiologíaRESUMEN
Continuous passive leg movement (PLM) is a promising clinical assessment of the age-related decline in peripheral vascular function. To further refine PLM, this study evaluated the efficacy of a single PLM (sPLM), a simplified variant of the more established continuous movement approach, to delineate between healthy young and old men based on vascular function. Twelve young (26 ± 5 yr) and 12 old (70 ± 7 yr) subjects underwent sPLM (a single passive flexion and extension of the knee joint through 90°), with leg blood flow (LBF, common femoral artery with Doppler ultrasound), blood pressure (finger photoplethysmography), and leg vascular conductance (LVC) assessed. A receiver operator characteristic curve analysis was used to determine an age-specific cut score, and a factor analysis was performed to assess covariance. Baseline LBF and LVC were not different between groups (P = 0.6). The high level of covariance and similar predictive value for all PLM-induced LBF and LVC responses indicates LBF, alone, can act as a surrogate variable in this paradigm. The peak sPLM-induced increase in LBF from baseline was attenuated in the old (Young: 717 ± 227, Old: 260 ± 97 ml/min, P < 0.001; cut score: 372 ml/min), as was the total LBF response (Young: 155 ± 67, Old: 26 ± 17 ml, P < 0.001; cut score: 58 ml). sPLM, a simplified version of PLM, exhibits the prerequisite qualities of a valid screening test for peripheral vascular dysfunction, as evidenced by an age-related attenuation in the peripheral hyperemic response and a clearly delineated age-specific cut score. NEW & NOTEWORTHY Single passive leg movement (sPLM) exhibits the prerequisite qualities of a valid screening test for peripheral vascular dysfunction. sPLM displayed an age-related reduction in the peripheral hemodynamic response for amplitude, duration, initial rate of change, and total change with clearly delineated age-specific cut scores. sPLM has a strong candidate variable that is a simple single numeric value, for which to appraise peripheral vascular function, the 45-s hyperemic response (leg blood flow area under the curve: 45 s).
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Arteria Femoral/fisiología , Pierna/fisiología , Movimiento/fisiología , Adulto , Presión Sanguínea/fisiología , Humanos , Hiperemia/fisiopatología , Masculino , Persona de Mediana Edad , Flujo Sanguíneo Regional/fisiologíaRESUMEN
OBJECTIVES: In 2013, the U.S. Army began developing physical tests to predict a recruit's ability to perform the critical, physically demanding tasks (CPDTs) of combat arms jobs previously not open to women. The purpose of this paper is to describe the methodology and results of analyses of the accuracy and inclusiveness of the critical physically demanding task list. While the job analysis included seven combat arms jobs, only data from the 19D Cavalry Scout occupation are presented as the process was similar for all seven jobs. DESIGN: Job analysis METHODS: As the foundation, senior subject matter experts from each job reviewed materials and reached consensus on the CPDTs and performance standards for each job. The list was reviewed by Army leadership and provided to the researchers. The job analysis consisted of reviewing job and task related documents and field manuals, observing >900 soldiers performing the 32 CPDTs, conducting two focus groups for each job, and analyzing responses to widely distributed job analysis questionnaires. RESULTS: Of the 32 CPDTs identified for seven combat jobs, nine were relevant to 19D soldiers. Focus group discussions and job analysis questionnaire results supported the tasks and standards identified by subject matter experts while also identifying additional tasks. CONCLUSIONS: The tasks identified by subject matter experts were representative of the physically demanding aspects of the 19D occupation.
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Personal Militar/estadística & datos numéricos , Ocupaciones/normas , Análisis y Desempeño de Tareas , Adulto , Análisis de Varianza , Femenino , Grupos Focales , Humanos , Masculino , Encuestas y Cuestionarios , Estados Unidos , Adulto JovenRESUMEN
Broxterman RM, Trinity JD, Gifford JR, Kwon OS, Kithas AC, Hydren JR, Nelson AD, Morgan DE, Jessop JE, Bledsoe AD, Richardson RS. Single passive leg movement assessment of vascular function: contribution of nitric oxide. J Appl Physiol 123: 1468-1476, 2017. First published August 31, 2017; doi:10.1152/japplphysiol.00533.2017.-The assessment of passive leg movement (PLM)-induced leg blood flow (LBF) and vascular conductance (LVC) is a novel approach to assess vascular function that has recently been simplified to only a single PLM (sPLM), thereby increasing the clinical utility of this technique. As the physiological mechanisms mediating the robust increase in LBF and LVC with sPLM are unknown, we tested the hypothesis that nitric oxide (NO) is a major contributor to the sPLM-induced LBF and LVC response. In nine healthy men, sPLM was performed with and without NO synthase inhibition by intra-arterial infusion of NG-monomethyl-l-arginine (l-NMMA). Doppler ultrasound and femoral arterial pressure were used to determine LBF and LVC, which were characterized by the peak change (ΔLBFpeak and ΔLVCpeak) and area under the curve (LBFAUC and LVCAUC). l-NMMA significantly attenuated ΔLBFpeak [492 ± 153 (l-NMMA) vs. 719 ± 238 (control) ml/min], LBFAUC [57 ± 34 (l NMMA) vs. 147 ± 63 (control) ml], ΔLVCpeak [4.7 ± 1.1 (l-NMMA) vs. 8.0 ± 3.0 (control) ml·min-1·mmHg-1], and LVCAUC [0.5 ± 0.3 (l-NMMA) vs. 1.6 ± 0.9 (control) ml/mmHg]. The magnitude of the NO contribution to LBF and LVC was significantly correlated with the magnitude of the control responses ( r = 0.94 for ΔLBFpeak, r = 0.85 for LBFAUC, r = 0.94 for ΔLVCpeak, and r = 0.95 for LVCAUC). These data establish that the sPLM-induced hyperemic and vasodilatory response is predominantly (~65%) NO-mediated. As such, sPLM appears to be a promising, simple, in vivo assessment of NO-mediated vascular function and NO bioavailability. NEW & NOTEWORTHY Passive leg movement (PLM), a novel assessment of vascular function, has been simplified to a single PLM (sPLM), thereby increasing the clinical utility of this technique. However, the role of nitric oxide (NO) in mediating the robust sPLM hemodynamic responses is unknown. This study revealed that sPLM induces a hyperemic and vasodilatory response that is predominantly NO-mediated and, as such, appears to be a promising simple, in vivo, clinical assessment of NO-mediated vascular function and, therefore, NO bioavailability.
Asunto(s)
Movimiento , Óxido Nítrico/fisiología , Flujo Sanguíneo Regional , Vasodilatación , Adulto , Presión Arterial , Inhibidores Enzimáticos/farmacología , Hemodinámica , Humanos , Hiperemia , Pierna/irrigación sanguínea , Masculino , Adulto Joven , omega-N-Metilarginina/farmacologíaRESUMEN
Hydren, JR, Borges, AS, and Sharp, MA. Systematic review and meta-analysis of predictors of military task performance: maximal lift capacity. J Strength Cond Res 31(4): 1142-1164, 2017-Physical performance tests (e.g., physical employment tests, return-to-duty tests) are commonly used to predict occupational task performance to assess the ability of individuals to do a job. The purpose of this systematic review was to identify predictive tests that correlate well with maximal lifting capacity in military personnel. Three databases were searched and experts in the field were contacted, resulting in the identification of 9 reports confined to military personnel that presented correlations between predictor tests and job tasks that measured maximal lift capacity. These 9 studies used 9 variations of a maximal lift capacity test, which were pooled to evaluate comparisons. The predictive tests were categorized into 10 fitness domains, which in ranked order were as follows: body mass and composition, absolute aerobic capacity, dynamic strength, power, isometric strength, strength-endurance, speed, isokinetic strength, flexibility, and age. Limitations of these data include a restricted age range (95% confidence interval [95% CI], 20-35; no correlations to maximal lift capacity) and the limited number of comparisons available within the cited studies. Weighted mean correlations ((Equation is included in full-text article.)) and 95% CI were calculated for each test. Lean body mass (kg) was the strongest overall predictor ((Equation is included in full-text article.); 95% CI, 0.697-0.966). Tests of dynamic strength had stronger correlations than strength endurance ((Equation is included in full-text article.), 95% CI, 0.69-0.89 vs. (Equation is included in full-text article.), 95% CI, 0.21-0.61). The following 6 domains of physical performance predictive tests had pooled correlations of 0.40 or greater for combined-sex samples: dynamic strength, power, isometric strength, strength endurance, speed, and isokinetic strength. Anthropometric measures explain 24-54% of maximal lift capacity variance, and lean body mass alone accounts for â¼69%. This review provides summarized information to assist in the selection of predictive tests for maximal lifting capacity in military personnel.
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Elevación , Personal Militar , Análisis y Desempeño de Tareas , Factores de Edad , Composición Corporal , Pesos y Medidas Corporales , Humanos , Fuerza Muscular/fisiología , Aptitud Física/fisiología , Reproducibilidad de los ResultadosRESUMEN
Dietary approaches for optimizing exercise performance have been debated in the literature for years. For endurance athletes, various position stands focus on recommendations for high-carbohydrate diets to maximize performance in events. However, theories of low-carbohydrate diets and their ability to provide more fuel may prove beneficial to ultraendurance athletes. Therefore, the purpose of this research was to observe the food and fluid consumption of successful recreational ultraendurance cyclists on the day before (ED-1), Event Day, and the day after (ED+1), a 162 km endurance event in a hot environment, and subsequently compare dietary intakes to recommendations and other observed dietary practices. Twenty men (age, 48 ± 8 years; mass, 85.1 ± 13.4 kg; height, 178.2 ± 7.4 cm) recorded all dietary items during ED-1, Event Day, and ED+1. Diet composition and the relationships between carbohydrate and caloric intake with finish time were examined. Results show athletes consumed a high-carbohydrate diet on ED-1 (384 g·d), Event Day (657 g·d), and ED+1 (329 g·d). However, there were no significant associations between carbohydrate (p > 0.05), or caloric intake (p > 0.05), and finish time. This study results great variation in diets of recreational endurance cyclists, although most consume within nationally recognized dietary recommendation ranges. Because there is great variation and lack of correlation with performance, these findings suggest that current high-carbohydrate dietary recommendations for general endurance athletes may not be sport specific or individualized enough for recreational ultraendurance cyclists, and that individualized dietary macronutrient composition manipulations may improve performance outcomes.
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Ciclismo/fisiología , Dieta de Carga de Carbohidratos/estadística & datos numéricos , Ingestión de Energía/fisiología , Conducta Alimentaria/fisiología , Calor , Resistencia Física/fisiología , Adulto , Ciclismo/psicología , Humanos , Masculino , Persona de Mediana EdadRESUMEN
Recent publications have provided new scientific evidence for a modern aerobic or cardiovascular endurance exercise prescription that optimizes the periodization cycle and maximizes potential endurance performance gains in highly trained individuals. The traditional threshold, high volume, and high-intensity training models have displayed limited improvement in actual race pace in (highly) trained individuals while frequently resulting in overreaching or overtraining (physical injury and psychological burnout). A review of evidence for replacing these models with the proven polarized training model seems warranted. This review provides a short history of the training models, summarizes 5 key studies, and provides example training programs for both the pre- and in-season periods. A polarized training program is characterized by an undulating nonlinear periodization model with nearly all the training time spent at a "light" (≤13) and "very hard" (≥17) pace with very limited time at "hard" (14-16) or race pace (6-20 Rating of Perceived Exertion [RPE] scale). To accomplish this, the polarization training model has specific high-intensity workouts separated by one or more long slow distance workouts, with the exercise intensity remaining below ventilatory threshold (VT) 1 and/or blood lactate of less than 2 mM (A.K.A. below race pace). Effect sizes for increasing aerobic endurance performance for the polarized training model are consistently superior to that of the threshold training model. Performing a polarized training program may be best accomplished by: going easy on long slow distance workouts, avoiding "race pace" and getting after it during interval workouts.