Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
Más filtros

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Am J Physiol Renal Physiol ; 326(4): F661-F668, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38385174

RESUMEN

Chronic kidney disease (CKD) is characterized by sympathetic nervous system (SNS) overactivity that contributes to increased vascular stiffness and cardiovascular risk. Although it is well established that SNS activity and vascular stiffness are substantially elevated in CKD, whether sex differences in autonomic and vascular function exist in CKD remains unknown. We tested the hypothesis that compared with females, males with CKD have higher baseline sympathetic activity that is related to increased arterial stiffness. One hundred twenty-nine participants (96 males and 33 females) with CKD stages III and IV were recruited and enrolled. During two separate study visits, vascular stiffness was assessed by measuring carotid-to-femoral pulse wave velocity (cfPWV), and resting muscle sympathetic nerve activity (MSNA) was measured by microneurography. Males with CKD had higher resting MSNA compared with females with CKD (68 ± 16 vs. 55 ± 14 bursts/100 heart beats, P = 0.005), whereas there was no difference in cfPWV between the groups (P = 0.248). Resting MSNA was not associated with cfPWV in both males and females. In conclusion, males with CKD have higher resting sympathetic activity compared with females with CKD. However, there was no difference in vascular stiffness between the sexes. There was no correlation between resting MSNA and cfPWV, suggesting that non-neural mechanisms may play a greater role in the progression of vascular stiffness in CKD, particularly in females.NEW & NOTEWORTHY Males with chronic kidney disease (CKD) have higher resting muscle sympathetic nerve activity (MSNA) compared with females. There was no correlation between MSNA and carotid-to-femoral pulse wave velocity (cfPWV), suggesting that non-neural mechanisms may play a greater role in the progression of vascular stiffness in CKD. Sex differences in SNS activity may play a mechanistic role in observations from epidemiological studies suggesting greater cardiovascular risk in males compared with females with CKD.


Asunto(s)
Insuficiencia Renal Crónica , Rigidez Vascular , Adulto , Humanos , Masculino , Femenino , Análisis de la Onda del Pulso , Caracteres Sexuales , Frecuencia Cardíaca , Sistema Nervioso Simpático , Insuficiencia Renal Crónica/diagnóstico , Rigidez Vascular/fisiología , Presión Sanguínea
2.
Microvasc Res ; 151: 104624, 2024 01.
Artículo en Inglés | MEDLINE | ID: mdl-37926135

RESUMEN

Vascular impairment is closely related to increased mortality in chronic kidney disease (CKD). The objective of this study was to assess impairments in the regulation of peripheral microvascular perfusion in patients with CKD based on time-frequency spectral analysis of resting near-infrared spectroscopy (NIRS) signals. Total hemoglobin (tHb) concentration and tissue saturation index (TSI) signals were collected using NIRS for a continuous 5 mins at 10 Hz from the forearm of 55 participants (34 CKD including 5 with end-stage renal disease, and 21 age-matched control). Continuous wavelet transform-based spectral analysis was used to quantify the spectral amplitude within five pre-defined frequency intervals (I, 0.0095-0.021 Hz; II, 0.021-0.052 Hz; III, 0.052-0.145 Hz; IV, 0.145-0.6 Hz and V, 0.6-2.0 Hz), representing endothelial, neurogenic, myogenic, respiratory and heartbeat activity, respectively. CKD patients showed lower tHb average spectral amplitude within the neurogenic frequency interval compared with controls (p = 0.014), consistent with an increased sympathetic outflow observed in CKD. CKD patients also showed lower TSI average spectral amplitude within the endothelial frequency interval compared with controls (p = 0.046), consistent with a reduced endothelial function in CKD. These findings demonstrate the potential of wavelet analysis of NIRS to provide complementary information on peripheral microvascular regulation in CKD.


Asunto(s)
Fallo Renal Crónico , Análisis de Ondículas , Humanos , Espectroscopía Infrarroja Corta , Microcirculación
3.
Am J Physiol Heart Circ Physiol ; 324(6): H843-H855, 2023 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-37000610

RESUMEN

Chronic kidney disease (CKD) is characterized by pronounced exercise intolerance and exaggerated blood pressure reactivity during exercise. Classic mechanisms of exercise intolerance in CKD have been extensively described previously and include uremic myopathy, chronic inflammation, malnutrition, and anemia. We contend that these classic mechanisms only partially explain the exercise intolerance experienced in CKD and that alterations in cardiovascular and autonomic regulation also play a key contributing role. The purpose of this review is to examine the physiological factors that contribute to neurocirculatory dysregulation during exercise and discuss the adaptations that result from regular exercise training in CKD. Key neurocirculatory mechanisms contributing to exercise intolerance in CKD include augmentation of the exercise pressor reflex, aberrations in neurocirculatory control, and increased neurovascular transduction. In addition, we highlight how some contributing factors may be improved through exercise training, with a specific focus on the sympathetic nervous system. Important areas for future work include understanding how the exercise prescription may best be optimized in CKD and how the beneficial effects of exercise training may extend to the brain.


Asunto(s)
Sistema Cardiovascular , Insuficiencia Renal Crónica , Humanos , Músculo Esquelético , Insuficiencia Renal Crónica/terapia , Ejercicio Físico/fisiología , Presión Sanguínea , Sistema Nervioso Simpático
4.
Clin Auton Res ; 33(6): 705-714, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37776374

RESUMEN

PURPOSE: Our aim was to test the hypothesis that patients with chronic kidney disease (CKD) would exhibit augmented resting beat-to-beat blood pressure variability (BPV) that is associated with poor clinical outcomes independent of mean blood pressure (BP). In addition, since the arterial baroreflex plays a critical role in beat-to-beat BP regulation, we further hypothesized that an impaired baroreflex control would be associated with an augmented resting beat-to-beat BPV. METHODS: In 25 sedentary patients with CKD stages III-IV (62 ± 9 years) and 20 controls (57 ± 10 years), resting beat-to-beat BP (finger photoplethysmography) and heart rate (electrocardiography) were continuously measured for 10 min. We calculated the standard deviation (SD), average real variability (ARV) and other indices of BPV. The sequence technique was used to estimate spontaneous cardiac baroreflex sensitivity. RESULTS: Compared with controls (CON), the CKD group had significantly increased resting BPV. The ARV (2.2 ± 0.6 versus 1.6 ± 0.5 mmHg, P < 0.001; 1.6 ± 0.7 versus 1.3 ± 0.3 mmHg, P = 0.039; 1.4 ± 0.5 versus 1.0 ± 0.2 mmHg, P < 0.001) of systolic, diastolic and mean BP, respectively, was increased in CKD versus controls. Other traditional measures of variability showed similar results. The cardiac baroreflex sensitivity was lower in CKD compared with controls (CKD: 8.4 ± 4.5 ms/mmHg versus CON: 14.0 ± 8.2 ms/mmHg, P = 0.008). In addition, cardiac baroreflex sensitivity was negatively associated with BPV [systolic blood pressure (SBP) ARV; r = -0.44, P = 0.003]. CONCLUSION: In summary, our data demonstrate that patients with CKD have augmented beat-to-beat BPV and lower cardiac baroreflex sensitivity. BPV and cardiac baroreflex sensitivity were negatively correlated in this cohort. These findings may further our understanding about cardiovascular dysregulation observed in patients with CKD.


Asunto(s)
Enfermedades del Sistema Nervioso Autónomo , Sistema Cardiovascular , Hipertensión , Insuficiencia Renal Crónica , Humanos , Presión Sanguínea/fisiología , Corazón , Frecuencia Cardíaca/fisiología , Barorreflejo/fisiología
5.
Clin Auton Res ; 33(6): 757-766, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37898568

RESUMEN

PURPOSE: Post-traumatic stress disorder (PTSD) is associated with greater risk of incident hypertension and cardiovascular disease (CVD). Inflammation and autonomic derangements are suggested as contributing mechanisms. Women and Black adults have higher CVD risk associated with stress; however, whether there is a sex difference in autonomic and inflammatory mechanisms among Black individuals with PTSD is not known. We hypothesized that Black women with PTSD have higher inflammation, sympathetic nervous system (SNS) activity and impaired baroreflex sensitivity (BRS). METHODS: In 42 Black Veterans with PTSD (Women, N = 18 and Men, N = 24), we measured inflammatory biomarkers, continuous blood pressure (BP), heart rate (HR) and muscle sympathetic nerve activity (MSNA) at rest and during arterial BRS testing via the modified Oxford technique. RESULTS: Groups were matched for age and body mass index (BMI). Resting BP was similar between groups, but HR was higher (76 ± 12 vs. 68 ± 9 beats/min, p = 0.021) in women compared to men. Although women had lower PTSD symptoms severity (57 ± 17 vs. 68 ± 12 a.u.), resting MSNA (27 ± 13 vs. 16 ± 5 bursts/min, p = 0.003) was higher in women compared to men, respectively. Likewise, cardiovagal BRS was blunted (p = 0.002) in women (7.6 ± 4.3 ms/mmHg) compared to men (15.5 ± 8.4 ms/mmHg) while sympathetic BRS was not different between groups (p = 0.381). Black women also had higher (p = 0.020) plasma levels of interleukin-2 (IL-2). CONCLUSION: Black women with PTSD have higher resting HR and MSNA, greater impairment of cardiovagal BRS and possibly higher inflammation. These findings suggest a higher burden of autonomic and inflammatory derangements in Black women compared to Black men with PTSD.


Asunto(s)
Enfermedades Cardiovasculares , Trastornos por Estrés Postraumático , Veteranos , Adulto , Humanos , Femenino , Masculino , Barorreflejo/fisiología , Trastornos por Estrés Postraumático/epidemiología , Caracteres Sexuales , Presión Sanguínea/fisiología , Sistema Nervioso Simpático , Frecuencia Cardíaca/fisiología , Inflamación , Músculo Esquelético
6.
Am J Physiol Endocrinol Metab ; 322(6): E508-E516, 2022 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-35373585

RESUMEN

Increased adiposity is associated with dysregulation of the endothelin system, both of which increase the risk of cardiovascular disease (CVD). Preclinical data indicate that endothelin dysregulation also reduces resting energy expenditure (REE). The objective was to test the hypothesis that endothelin receptor antagonism will increase REE in people with obesity compared with healthy weight individuals. Using a double blind, placebo-controlled, crossover design, 32 participants [healthy weight (HW): n = 16, BMI: 21.3 ± 2.8 kg/m2, age: 26 ± 7 yr and overweight/obese (OB): n = 16, BMI: 33.5 ± 9.5 kg/m2, age: 31 ± 6 yr] were randomized to receive either 125 mg of bosentan (ETA/B antagonism) or placebo twice per day for 3 days. Breath-by-breath gas exchange data were collected and REE was assessed by indirect calorimetry. Venous blood samples were analyzed for concentrations of endothelin-1 (ET-1). Treatment with bosentan increased plasma ET-1 in both OB and HW groups. Within the OB group, the changes in absolute REE (PLA: -77.6 ± 127.6 vs. BOS: 72.2 ± 146.6 kcal/day; P = 0.046). The change in REE was not different following either treatment in the HW group. Overall, absolute plasma concentrations of ET-1 following treatment with bosentan were significantly associated with kcal/day of fat (r = 0.488, P = 0.005), percentage of fat utilization (r = 0.415, P = 0.020), and inversely associated with the percentage of carbohydrates (r = -0.419, P = 0.019), and respiratory exchange ratio (r = -0.407, P = 0.023). Taken together, these results suggest that modulation of the endothelin system may represent a novel therapeutic approach to increase both resting metabolism and caloric expenditure, and reduce CVD risk in people with increased adiposity.NEW & NOTEWORTHY Findings from our current translational investigation demonstrate that dual endothelin A/B receptor antagonism increases total REE in overweight/obese individuals. These results suggest that modulation of the endothelin system may represent a novel therapeutic target to increase both resting metabolism and caloric expenditure, enhance weight loss, and reduce CVD risk in seemingly healthy individuals with elevated adiposity.


Asunto(s)
Adiposidad , Enfermedades Cardiovasculares , Adulto , Metabolismo Basal , Bosentán , Calorimetría Indirecta , Endotelinas/metabolismo , Metabolismo Energético , Humanos , Obesidad/metabolismo , Sobrepeso/metabolismo , Receptores de Endotelina/metabolismo , Adulto Joven
7.
Am J Physiol Regul Integr Comp Physiol ; 319(6): R611-R616, 2020 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-32966119

RESUMEN

Posttraumatic stress disorder (PTSD) is an independent risk factor for the development of hypertension and cardiovascular disease. Patients with PTSD have heightened blood pressure and sympathetic nervous system reactivity; however, it is unclear if patients with PTSD have exaggerated vasoconstriction in response to sympathetic nerve activation that could also contribute to increased blood pressure reactivity. Therefore, we hypothesized that patients with PTSD have increased sensitivity of vascular α1-adrenergic receptors (α1ARs), the major mediators of vasoconstriction in response to release of norepinephrine at sympathetic nerve terminals. To assess vascular α1AR sensitivity, we measured the degree of venoconstriction in a dorsal hand vein in response to exponentially increasing doses of the selective α1AR agonist, phenylephrine (PE), in 9 patients with PTSD (age = 59 ± 2 yr) and 10 age-matched controls (age = 60 ± 1 yr). Individual dose-response curves were generated to determine the dose of PE that induces 50% of maximal venoconstriction (i.e., PE ED50) reflective of vascular α1AR sensitivity. In support of our hypothesis, PE ED50 values were lower in PTSD compared with controls (245 ± 54 ng/min vs. 1,995 ± 459 ng/min, P = 0.012), indicating increased vascular α1AR sensitivity in PTSD. The PTSD group also had an increase in slope of rise in venoconstriction, indicative of an altered venoconstrictive reactivity to PE compared with controls (19.8% ± 1.2% vs. 15.1% ± 1.2%, P = 0.009). Heightened vascular α1AR sensitivity in PTSD may contribute to augmented vasoconstriction and blood pressure reactivity to sympathoexcitation and to increased cardiovascular disease risk in this patient population.


Asunto(s)
Envejecimiento/metabolismo , Receptores Adrenérgicos alfa 1/metabolismo , Trastornos por Estrés Postraumático/metabolismo , Sistema Nervioso Simpático/metabolismo , Vasoconstricción , Agonistas de Receptores Adrenérgicos alfa 1/administración & dosificación , Factores de Edad , Presión Sanguínea , Estudios de Casos y Controles , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Infusiones Intravenosas , Masculino , Persona de Mediana Edad , Fenilefrina/administración & dosificación , Receptores Adrenérgicos alfa 1/efectos de los fármacos , Transducción de Señal , Trastornos por Estrés Postraumático/fisiopatología , Sistema Nervioso Simpático/efectos de los fármacos , Sistema Nervioso Simpático/fisiopatología , Vasoconstricción/efectos de los fármacos
8.
medRxiv ; 2024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-38699306

RESUMEN

Background: Chronic kidney disease (CKD) is characterized by overactivation of the sympathetic nervous system (SNS) that leads to increased cardiovascular disease risk. Despite the deleterious consequences of SNS overactivity, there are very few therapeutic options available to combat sympathetic overactivity. Aim: To evaluate the effects of Mindfulness-Based Stress Reduction (MBSR) on SNS activity in CKD patients. Method: Participants with CKD stages III-IV were randomized to an 8-week MBSR program or Health Education Program (HEP; a structurally parallel, active control group). Primary outcomes were direct intraneural measures of SNS activity directed to muscle (MSNA) via microneurography at rest and during stress maneuvers. Results: 28 participants (63 ±9 years; 86% males) completed the intervention with 16 in MBSR and 12 in HEP. There was a significant Group (MBSR vs. HEP) by Time (baseline vs. post-intervention) interaction in the change in MSNA reactivity to mental stress (p=0.026), with a significant reduction in the mean change in MSNA over 3 minutes of mental arithmetic at post-intervention (10.6 ± 7.1 to 5.0 ± 5.7 bursts/min, p<0.001), while no change was observed within the HEP group (p=0.773). Conclusions: In this randomized controlled trial, patients with CKD had an amelioration of sympathetic reactivity during mental stress following 8-weeks of MBSR but not after HEP. Our findings demonstrate that mindfulness training is feasible and may have clinically beneficial effects on autonomic function in CKD.

9.
Hortic Res ; 11(9): uhae187, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39247884

RESUMEN

Agrobacterium-mediated transformation remains a cornerstone of plant biology, fueling advancements in molecular genetics, new genomic techniques (NGTs), and the biotech industry. However, recalcitrant crops and technical hurdles persist as bottlenecks. The goal was to develop super-infective ternary vector systems that integrate a novel salicylic acid-degrading enzyme, GABA, and ethylene-degrading enzymes, targeting the transformation of crops by neutralizing plant defense system on Agrobacterium. Firstly, both the effect and activity of introducing enzymes were validated in EHA105, an important Agrobacterium strain. Our study demonstrates that all ternary vector (Tv) system variants significantly enhance reporter expression in transient assays with Nicotiana benthamiana and Cannabis sativa. Specifically, incorporating a constitutive virG mutation with novel enzyme combinations increased GFP and RUBY expression in C. sativa by >5-fold and 13-fold, respectively. The Tv system, combined with a geminivirus replicon, markedly boosted GUS gene expression in tomato, enhancing genome editing efficiency. Notably, compared to controls, Tv-VS demonstrated up to 18-fold and 4.5-fold increases in genome editing efficiency in C. sativa and tomato, respectively. Additionally, stable transformation rates in tomato and Arabidopsis improved significantly, with Tv-VS showing a remarkable 2.5-fold increase in transformation efficiency compared to control strains. The research marks notable progress in Agrobacterium-mediated plant transformation. The innovative ternary vectors overcome plant defense mechanisms, enabling genetic manipulation in previously challenging plant species. This development is anticipated to broaden the applications of plant genetic engineering, contributing to advancements in crop genome editing.

10.
Kidney Blood Press Res ; 37(2-3): 142-50, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23653111

RESUMEN

BACKGROUND: End-stage renal disease patients experience increased prevalence of cardiovascular disease. Heart-artery interaction may be shifted, impacting blood pressure lability, and exercise tolerance. The coupling ratio consists of the ratio of indexed arterial elastance (EaI, arterial load) to ElvI, a measure of cardiac contractility or stiffness. Our purpose was to explore the relationship between elastances and functional capacity. We hypothesized that arterial stiffness (central pulse wave velocity, PWV) and elastances would be correlated to shuttle walk time. METHODS: We used applanation tonometry, ultrasonography, and a shuttle walk test to evaluate our hypothesis. Spearman's correlations were used to assess relationships between variables. Block regression was also performed. RESULTS: Forty-two subjects on maintenance hemodialysis participated. Average age=44±5 years, body surface area=2.01 kg/m(2). Mean EaI=4.45 and mean ElvI=6.89; the coupling ratio=0.82. Mean aortic pulse pressure=51 mmHg and PWV=9.6 m/s. PWV(r=-0.385) and EaI (r=-0.424) were significantly and inversely related to walking time while stroke volume index (SVI) was positively correlated to shuttle walk time (r=0.337), p<0.05 for all. CONCLUSIONS: We conclude that, like other clinical populations, both arterial and heart function predict walking ability and represent potential targets for intervention; arterial stiffness and SVI are strongly related to shuttle walk time in patients with ESRD.


Asunto(s)
Fallo Renal Crónico/fisiopatología , Rigidez Vascular/fisiología , Caminata/fisiología , Adulto , Anciano , Antropometría , Presión Sanguínea/fisiología , Complicaciones de la Diabetes/fisiopatología , Elasticidad , Electrocardiografía , Femenino , Humanos , Masculino , Manometría , Persona de Mediana Edad , Pulso Arterial , Análisis de Regresión , Diálisis Renal
11.
JCI Insight ; 8(4)2023 02 22.
Artículo en Inglés | MEDLINE | ID: mdl-36810250

RESUMEN

BACKGROUNDChronic kidney disease (CKD) is characterized by chronic overactivation of the sympathetic nervous system (SNS), which increases the risk of cardiovascular (CV) disease and mortality. SNS overactivity increases CV risk by multiple mechanisms, including vascular stiffness. We tested the hypothesis that aerobic exercise training would reduce resting SNS activity and vascular stiffness in patients with CKD.METHODSIn this randomized controlled trial, sedentary older adults with CKD underwent 12 weeks of exercise (cycling, n = 32) or stretching (an active control group, n = 26). Exercise and stretching interventions were performed 20-45 minutes/session at 3 days/week and were matched for duration. Primary endpoints include resting muscle sympathetic nerve activity (MSNA) via microneurography, arterial stiffness by central pulse wave velocity (PWV), and aortic wave reflection by augmentation index (AIx).RESULTSThere was a significant group × time interaction in MSNA and AIx with no change in the exercise group but with an increase in the stretching group after 12 weeks. The magnitude of change in MSNA was inversely associated with baseline MSNA in the exercise group. There was no change in PWV in either group over the study period.CONCLUSIONOur data demonstrate that 12 weeks of cycling exercise has beneficial neurovascular effects in patients with CKD. Specifically, exercise training safely and effectively ameliorated the increase in MSNA and AIx observed over time in the control group. This sympathoinhibitory effect of exercise training showed greater magnitude in patients with CKD with higher resting MSNA.TRIAL REGISTRATIONClinicalTrials.gov, NCT02947750.FUNDINGNIH R01HL135183; NIH R61AT10457; NIH NCATS KL2TR002381; and NIH T32 DK00756; NIH F32HL147547; and VA Merit I01CX001065.


Asunto(s)
Enfermedades Cardiovasculares , Insuficiencia Renal Crónica , Rigidez Vascular , Humanos , Anciano , Análisis de la Onda del Pulso , Ejercicio Físico/fisiología , Insuficiencia Renal Crónica/complicaciones , Rigidez Vascular/fisiología
12.
Physiol Rep ; 10(21): e15495, 2022 11.
Artículo en Inglés | MEDLINE | ID: mdl-36325592

RESUMEN

Chronic Kidney Disease (CKD) patients experience an elevated risk for cerebrovascular disease. One factor that may contribute to this heightened risk is an impairment in dynamic cerebral autoregulation, the mechanism by which cerebral vessels modulate cerebral blood flow during fluctuations in arterial pressure. We hypothesized that dynamic cerebral autoregulation would be impaired in CKD. To test this hypothesis, we compared dynamic cerebral autoregulation between CKD patients stages III-IV and matched controls (CON) without CKD. Fifteen patients with CKD and 20 CON participants performed 2, 5-minute bouts of repeated sit-to-stand maneuvers at 0.05 Hz and 0.10 Hz while mean arterial pressure (MAP, via finger photoplethysmography) and middle cerebral artery blood velocity (MCAv, via transcranial Doppler ultrasound) were measured continuously. Cerebral autoregulation was characterized by performing a transfer function analysis (TFA) on the MAP-MCAv relationship to derive coherence, phase, gain, and normalized gain (nGain). We observed no group differences in any of the TFA metrics during the repeated sit-to-stand maneuvers. During the 0.05 Hz maneuver, Coherence: CKD = 0.83 ± 0.13, CON = 0.85 ± 0.12, Phase (radians): CKD = 1.39 ± 0.41, CON = 1.25 ± 0.30, Gain (cm/s/mmHg): CKD = 0.69 ± 0.20, CON = 0.71 ± 0.22, nGain (%/mmHg): CKD = 1.26 ± 0.35, CON = 1.20 ± 0.28, p ≥ 0.24. During the 0.10 Hz maneuver (N = 6 CKD and N = 12 CON), Coherence: CKD = 0.61 ± 0.10, CON = 0.67 ± 0.11, Phase (radians): CKD = 1.43 ± 0.26, CON = 1.30 ± 0.23, Gain (cm/s/mmHg): CKD = 0.75 ± 0.15, CON = 0.84 ± 0.26, nGain (%/mmHg): CKD = 1.50 ± 0.28, CON = 1.29 ± 0.24, p ≥ 0.12. Contrary to our hypothesis, dynamic cerebral autoregulation remains intact in CKD stages III-IV. These findings suggest that other mechanisms likely contribute to the increased cerebrovascular disease burden experienced by this population. Future work should determine if other cerebrovascular regulatory mechanisms are impaired and related to cerebrovascular disease risk in CKD.


Asunto(s)
Circulación Cerebrovascular , Insuficiencia Renal Crónica , Humanos , Velocidad del Flujo Sanguíneo/fisiología , Homeostasis/fisiología , Circulación Cerebrovascular/fisiología , Ultrasonografía Doppler Transcraneal , Arteria Cerebral Media/fisiología , Presión Sanguínea/fisiología
13.
J Appl Physiol (1985) ; 132(3): 785-793, 2022 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-35142559

RESUMEN

Patients with chronic kidney disease (CKD) have exaggerated increases in blood pressure during exercise that are associated with endothelial dysfunction. We hypothesized that aerobic exercise training would improve endothelial function and attenuate blood pressure reactivity during exercise in CKD. Sedentary individuals with CKD stages III-IV underwent 12 wk of aerobic cycling exercise (n = 26) or nonaerobic exercise (n = 22, control). Both interventions were performed 3 days/wk and matched for duration. Endothelial function was measured via peripheral arterial tonometry and quantified as reactive hyperemia index (RHI). Peak oxygen uptake (V̇o2peak) was assessed via maximal treadmill exercise testing with concomitant blood pressure monitoring. All measurements were performed at baseline and after the 12-wk intervention. A linear mixed model was used to compare the rate of increase in blood pressure during the test. RHI improved with exercise (Pre = 1.78 ± 0.10 vs. Post = 2.01 ± 0.13, P = 0.03) with no change following stretching (Pre = 1.73 ± 0.08 vs. Post = 1.67 ± 0.10, P = 0.69). Peak systolic blood pressure during the maximal treadmill exercise test was lower after exercise training (Pre = 186 ± 5 mmHg, Post = 174 ± 4 mmHg, P = 0.003) with no change after stretching (Pre = 190 ± 6 mmHg, Post = 190 ± 4 mmHg, P = 0.12). The rate of increase in systolic blood pressure during the V̇o2peak test tended to decrease after training for both groups (-2 mmHg/stage) with no differences between groups (P = 0.97). There was no change in V̇o2peak after either intervention. In conclusion, aerobic exercise training improves endothelial function and attenuates peak blood pressure reactivity during exercise in CKD.NEW & NOTEWORTHY Patients with chronic kidney disease (CKD) exhibit increased blood pressure reactivity during exercise that is associated with endothelial dysfunction. Twelve weeks of structured, aerobic, exercise training improves endothelial function and attenuates peak blood pressure responses during exercise in CKD stages III-IV.


Asunto(s)
Ejercicio Físico , Insuficiencia Renal Crónica , Presión Sanguínea/fisiología , Ejercicio Físico/fisiología , Prueba de Esfuerzo , Terapia por Ejercicio , Femenino , Humanos , Masculino , Insuficiencia Renal Crónica/complicaciones , Insuficiencia Renal Crónica/terapia
14.
Physiol Rep ; 10(10): e15335, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35593213

RESUMEN

Upregulation of endothelin-1 (ET-1) is the hallmark of various cardiovascular diseases (CVD). The purpose of the present study was to assess the ET-1 response to an acute bout of whole-body vibration (WBV) in humans and to determine the role of adiposity. Twenty-two participants volunteered for the study; they were grouped into overweight/obese [(OW/OB): n = 11, Age: 33 ± 4 years, Body mass index (BMI): 35 ± 10 kg/m2 ] or normal weight [(NW): n = 11, Age: 28 ± 7 years, BMI: 21 ± 2 kg/m2 ]. Participants engaged in 10 cycles of WBV exercise (1 cycle = 1 min WBV followed by 30 s of rest). Blood samples were analyzed for ET-1 pre-WBV (PRE), immediately post (POST), 1 h (1H), 3 h (3H), and 24 h (24H) post-WBV. There was a significant time main effect of WBV on circulating ET-1 (F = 12.5, p < 0.001); however, the ET-1 response was similar (F = 0.180, p = 0.677) between groups. Specifically, compared to PRE, a significant increase in ET-1 was observed at 1H (p = 0.017) and 3H (p = 0.025). In addition, concentrations of ET-1 were significantly lower at 24H compared to PRE (p = 0.019), 1H (p < 0.001), and 3H (p < 0.001). Maximal oxygen uptake during WBV was similar between the two groups. Acute WBV resulted in an initial rise in ET-1, followed by a significantly lower ET-1 at 24H in both groups. Findings support the utility of routine WBV exercise to elicit a decrease in ET-1 and improve CVD risk, similar to what has been reported with traditional modes of exercise.


Asunto(s)
Enfermedades Cardiovasculares , Vibración , Adulto , Endotelina-1 , Ejercicio Físico/fisiología , Humanos , Obesidad/terapia , Adulto Joven
15.
Food Chem ; 360: 130063, 2021 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-34029927

RESUMEN

Here, we detail the biomineralization-assisted separation and concentration of crude food extract and an evaluation of its effectiveness. Schisandra chinensis fruit extract was used as a model plant extract. Hybrid grape-like mineral was assembled by calcium carbonate mineralization. The hybrid particles of S. chinensis mineral were fully characterized using field emission scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, and particle size analysis. Data including the Brunauer-Emmett-Teller surface area, single point total pore volume, and adsorption/desorption analysis of pore size were also investigated. Organic molecules, including lipids such as palmitic acid, stearic acid, and linolenic acid in the Schisandra chinensis fruit, affect the formation of complex structures involving the CaCO3 mineralization pathway by inhibiting crystallization. However, the cosmetic active primary components were entrapped in a similar proportion in the preserved extract, and were efficiently separated without additional filtering and concentration steps for purification. In addition, the hybrid mineral was enriched (10.5 times) in Gomisin N, a representative component of S. chinensis fruit, relative to its concentration in the initial extract samples. The hybrid mineral inhibited both intracellular and extracellular melanin production and increased the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity. The data provide the first evidence of the potential use of fruit extract for obtaining hybrid minerals and the effectiveness of the biomineralization-based separation and concentration strategy.


Asunto(s)
Extractos Vegetales/química , Schisandra/química , Animales , Antioxidantes/química , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Ciclooctanos/química , Ciclooctanos/aislamiento & purificación , Ciclooctanos/farmacología , Frutas/química , Frutas/metabolismo , Lignanos/química , Lignanos/aislamiento & purificación , Lignanos/farmacología , Ratones , Extractos Vegetales/farmacología , Compuestos Policíclicos/química , Compuestos Policíclicos/aislamiento & purificación , Compuestos Policíclicos/farmacología , Schisandra/metabolismo
16.
IEEE Trans Med Imaging ; 40(12): 3617-3626, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34191724

RESUMEN

Magnetic resonance imaging (MRI) can provide multiple contrast-weighted images using different pulse sequences and protocols. However, a long acquisition time of the images is a major challenge. To address this limitation, a new pulse sequence referred to as quad-contrast imaging is presented. The quad-contrast sequence enables the simultaneous acquisition of four contrast-weighted images (proton density (PD)-weighted, T2-weighted, PD-fluid attenuated inversion recovery (FLAIR), and T2-FLAIR), and the synthesis of T1-weighted images and T1- and T2-maps in a single scan. The scan time is less than 6 min and is further reduced to 2 min 50 s using a deep learning-based parallel imaging reconstruction. The natively acquired quad contrasts demonstrate high quality images, comparable to those from the conventional scans. The deep learning-based reconstruction successfully reconstructed highly accelerated data (acceleration factor 6), reporting smaller normalized root mean squared errors (NRMSEs) and higher structural similarities (SSIMs) than those from conventional generalized autocalibrating partially parallel acquisitions (GRAPPA)-reconstruction (mean NRMSE of 4.36% vs. 10.54% and mean SSIM of 0.990 vs. 0.953). In particular, the FLAIR contrast is natively acquired and does not suffer from lesion-like artifacts at the boundary of tissue and cerebrospinal fluid, differentiating the proposed method from synthetic imaging methods. The quad-contrast imaging method may have the potentials to be used in a clinical routine as a rapid diagnostic tool.


Asunto(s)
Procesamiento de Imagen Asistido por Computador , Protones , Artefactos , Encéfalo/diagnóstico por imagen , Imagen por Resonancia Magnética
17.
ACS Omega ; 5(45): 29577-29584, 2020 Nov 17.
Artículo en Inglés | MEDLINE | ID: mdl-33225189

RESUMEN

This study details the preparation and application of supramolecular host-guest inclusion complexes entrapping biomineralized microspheres for long-term storage and their pH-responsive behavior. The microspheres were assembled using a CaCO3 synthesis process coupled with cyclodextrin-tetrahydrocurcumin (CD-THC) inclusion complexes, forming fine-textured and mechanically stable hybrid materials. The products were successfully characterized using field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), and particle size analysis (PSA). Various parameters such as the Brunauer-Emmett-Teller (BET) surface area, single point total pore volume, and pore size via adsorption/desorption analysis were also determined. The obtained THC-entrapped hybrid microspheres contained as high as 20 wt % THC loading and were very stable, preserving 90% of the initial concentration over four weeks of storage at different temperatures, largely limiting THC leaching and indicating high stability in a physiological environment. In addition, the pH-responsive release of THC from the hybrid microspheres was observed, showing potential use for application to weakly acidic skin surfaces. To our knowledge, this is the first demonstration of antiaging cosmetic formulation technology using biomineralization based on the co-synthesis of CaCO3 and CD-THC complexes.

18.
Brain Behav Immun Health ; 1: 100011, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38377415

RESUMEN

Traditional aerobic exercise reduces the risk of developing chronic diseases by inducing immune, metabolic, and myokine responses. Following traditional exercise, both the magnitude and time-course of these beneficial responses are different between obese compared to normal weight individuals. Although obesity may affect the ability to engage in traditional exercise, whole body vibration (WBV) has emerged as a more tolerable form of exercise . The impact of WBV on immune, metabolic, and myokine responses as well as differences between normal weight and obese individuals, however, is unknown. Purpose: To determine if WBV elicits differential magnitudes and time-courses of immune, metabolic, and myokine responses between obese and normal weight individuals. Methods: 21 participants [Obese (OB): n = 11, Age: 33 ±â€¯4 y, percent body fat (%BF): 39.1 ±â€¯2.4% & Normal weight (NW) n = 10, Age: 28 ±â€¯8 y, %BF: 17.4 ±â€¯2.1%] engaged in 10 cycles of WBV exercise [1 cycle = 1 min of vibration followed by 30 s of rest]. Blood samples were collected pre-WBV (PRE), immediately (POST), 3 h (3H), and 24 h (24H) post-WBV and analyzed for leukocytes, insulin, glucose, and myokines (IL-6, decorin, myostatin). Results: The peak (3H) percent change in neutrophil counts (OB: 13.9 ±â€¯17.4 vs. NW: 47.2 ±â€¯6.2%Δ; p = 0.007) was different between groups. The percent change in neutrophil percentages was increased in NW (POST: -1.6 ±â€¯2.0 vs. 3H: 13.0 ±â€¯7.2%Δ, p = 0.019) but not OB (p > 0.05). HOMA ß-cell function was increased at 24H (PRE: 83.4 ±â€¯5.4 vs. 24H: 131.0 ±â€¯14.1%; p = 0.013) in NW and was not altered in OB (p > 0.05). PRE IL-6 was greater in OB compared to NW (OB: 2.7 ±â€¯0.6 vs. NW: 0.6 ±â€¯0.1 pg/mL; p = 0.011); however, the percent change from PRE to peak (3H) was greater in NW (OB: 148.1 ±â€¯47.9 vs. NW: 1277.9 ±â€¯597.6 %Δ; p = 0.035). Creatine kinase, decorin, and myostatin were not significantly altered in either group (p > 0.05). Conclusion: Taken together, these data suggest that acute whole body vibration elicits favorable immune, metabolic, and myokine responses and that these responses differ between obese and normal weight individuals.

19.
Artículo en Inglés | MEDLINE | ID: mdl-31635209

RESUMEN

Background: The number of married female immigrants living in Korea has been increasing and is expected to increase further. This study was performed to identify factors associated with national general health screening participation among married immigrant women living in South Korea. Methods: The Korean National Health Insurance System's (NHIS) customized database for the years 2014 and 2015 was used. The targets of this study were women aged 19 years old and above. To identify factors associated with national general health screening participation, the following analyses were employed: frequency, chi-square, simple regression, and multiple regression. Results: A total of 11,213 women were identified in the NHIS database. Overall, 67.4% participated in national general health screenings, lower than the 74.6% participation rate of the entire women's health screening program. Married immigrant women with a job had higher health screening participation than those without a job (OR = 2.822, p < 0.0001). Age, socioeconomic status, and duration of stay were related to health screening behaviors among employed married immigrant women. Nationality, socioeconomic status, duration of stay, and disease status were associated with general health screening behaviors among unemployed immigrant women. The odds ratios decreased as the length of stay increased, regardless of employment status. Conclusion: The results of this study showed that employment status and duration of stay in Korea are significantly associated with general health screening participation. Accordingly, to improve awareness about health screening and health care disparities, programs promoting health screening participation for socially vulnerable classes, including immigrant women and unemployed women, should be instigated.


Asunto(s)
Emigrantes e Inmigrantes , Tamizaje Masivo , Aceptación de la Atención de Salud/etnología , Salud de la Mujer , Adulto , Concienciación , Emigrantes e Inmigrantes/estadística & datos numéricos , Femenino , Encuestas de Atención de la Salud , Humanos , Matrimonio , Tamizaje Masivo/estadística & datos numéricos , Persona de Mediana Edad , República de Corea , Adulto Joven
20.
Am J Hypertens ; 32(10): 968-974, 2019 09 24.
Artículo en Inglés | MEDLINE | ID: mdl-31112592

RESUMEN

BACKGROUND: Ethnic differences in nighttime blood pressure (BP) have long been documented with African Americans (AAs) having higher BP than European Americans (EAs). At present, lower nighttime melatonin, a key regulator of circadian rhythms, has been associated with higher nighttime BP levels in EAs. This study sought to test the hypothesis that AAs have lower nighttime melatonin secretion compared with EAs. We also determined if this ethnic difference in melatonin could partially explain the ethnic difference in nighttime BP. METHODS: A total of 150 young adults (71 AA; 46% females; mean age: 27.7 years) enrolled in the Georgia Stress and Heart study provided an overnight urine sample for the measurement of 6-sulfatoxymelatonin, a major metabolite of melatonin. Urine melatonin excretion (UME) was calculated as the ratio between 6-sulfatoxymelatonin concentration and creatinine concentration. Twenty-four-hour ambulatory BP was assessed and nighttime systolic BP (SBP) was used as a major index of BP regulation. RESULTS: After adjustment of age, sex, body mass index, and smoking, AAs had significantly lower UME (P = 0.002) and higher nighttime SBP than EAs (P = 0.036). Lower UME was significantly associated with higher nighttime SBP and this relationship did not depend on ethnicity. The ethnicity difference in nighttime SBP was significantly attenuated after adding UME into the model (P = 0.163). CONCLUSION: This study is the first to document the ethnic difference in nighttime melatonin excretion, demonstrating that AAs have lower melatonin secretion compared with EAs. Furthermore, the ethnic difference in nighttime melatonin can partially account for the established ethnic difference in nighttime SBP.


Asunto(s)
Negro o Afroamericano , Presión Sanguínea , Ritmo Circadiano , Disparidades en el Estado de Salud , Hipertensión/etnología , Melatonina/orina , Población Blanca , Adulto , Biomarcadores/orina , Femenino , Georgia/epidemiología , Humanos , Hipertensión/diagnóstico , Hipertensión/fisiopatología , Hipertensión/orina , Masculino , Factores Raciales , Factores de Riesgo , Factores de Tiempo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA