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1.
Sensors (Basel) ; 20(11)2020 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-32517290

RESUMEN

The steadily growing elderly population calls for efficient, reliable and preferably ambulant health supervision. Since cardiovascular risk factors interact with psychosocial strain (e.g., depression), we investigated the potential contribution of psychosocial factors in discriminating generally healthy elderly from those with a cardiovascular condition, on and above routinely applied physiological assessments. Fifteen elderly (aged 60 to 88) with a cardiovascular diagnosis were compared to fifteen age and gender matched healthy peers. Six sequential standardized lab assessments were conducted (one every two weeks), including an autonomic test battery, a 6-min step test and questionnaires covering perceived psychological state and experiences over the previous two weeks. Specific combinations of physiological and psychological factors (most prominently symptoms of depression) effectively predicted (clinical) cardiovascular markers. Additionally, a highly significant prognostic model was found, including depressive symptoms, recently experienced negative events and social isolation. It appeared slightly superior in identifying elderly with or without a cardiovascular condition compared to a model that only included physiological parameters. Adding psychosocial parameters to cardiovascular assessments in elderly may consequently provide protocols that are significantly more efficient, relatively comfortable and technologically feasible in ambulant settings, without necessarily compromising prognostic accuracy.


Asunto(s)
Factores de Riesgo de Enfermedad Cardiaca , Modelos Psicológicos , Monitoreo Ambulatorio , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Depresión , Humanos , Persona de Mediana Edad , Aislamiento Social , Estrés Psicológico , Volumen Sistólico , Encuestas y Cuestionarios , Función Ventricular Izquierda
2.
Eur J Appl Physiol ; 120(4): 799-809, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32076831

RESUMEN

INTRODUCTION: High-altitude ascent induces left (LV) and right (RV) ventricular adaptations secondary to hypoxia-related hemodynamic and myocardial alterations. Since cardiopulmonary decrements observed with aging (e.g., decreased LV compliance and increased pulmonary vascular resistance) may limit cardiac plasticity, this study examined myocardial adaptability throughout an 11 day sojourn to 5893 m in young and older-aged trekkers. METHODS AND RESULTS: Echocardiography was performed on 14 young (8 men; 32 ± 5 years) and 13 older-aged (8 men; 59 ± 5 years) subjects on non-trekking days (Day 0: 880 m; Day 3: 3100 m; Day 8: 4800 m; Day 12/post-climb: 880 m). RV systolic pressure (mmHg) was systematically higher in older-aged subjects (p < 0.01) with similar progressive increases observed during ascent for young and older subjects, respectively (Day 0: 18 ± 1 vs 20 ± 2; Day 3: 25 ± 2 vs 29 ± 3; Day 8: 30 ± 2 vs 35 ± 2). Estimates of LV filling pressure (E/E') were systematically higher in older subjects (p < 0.01) with similar progressive decreases observed during ascent for young and older-aged subjects, respectively (Day 0: 5.6 ± 0.3 vs 6.7 ± 0.5; Day 3: 5.1 ± 0.2 vs 6.1 ± 0.3; Day 8: 4.7 ± 0.3 vs 5.4 ± 0.3). Overall, RV end-diastolic and end-systolic area increased at altitude (p < 0.01), while LV end-diastolic and end-systolic volume decreased (p < 0.01). However, all RV and LV morphological measures were similar on Day 3 and Day 8 (p > 0.05), and returned to baseline post-climb (p > 0.05). Excluding mild LV dilatation in some older-aged trekkers on Day 8/Day 12 (p < 0.01), altitude-induced morphological and functional adaptations were similar for all trekkers (p > 0.05). CONCLUSION: Altitude-induced myocardial adaptations are chamber specific, secondary to RV and LV hemodynamic alterations. Despite progressive hemodynamic alterations during ascent, morphological and functional cardiac perturbations plateaued, suggesting rapid myocardial adaptation which was mostly comparable in young and older-aged individuals.


Asunto(s)
Aclimatación , Envejecimiento/fisiología , Corazón/fisiología , Montañismo/fisiología , Circulación Pulmonar , Adulto , Anciano , Altitud , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto Joven
3.
Rheumatol Ther ; 6(3): 317-338, 2019 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-31385263

RESUMEN

INTRODUCTION: In 2016, SB4 (Benepali®) became the first etanercept (ETN) biosimilar to obtain marketing authorisation in Europe. Despite robust analytical and clinical comparisons, outstanding questions remain on SB4 use in routine practice. METHODS: A systematic search for publications on real-world evidence of SB4 effectiveness, safety and drug survival was undertaken using search terms (SB4 OR Benepali OR biosimilar etanercept OR innovator etanercept) in the BIOSIS® Toxicology, BIOSIS Previews®, Embase® and MEDLINE® databases up to 17 January 2019. RESULTS: Of 959 articles identified, eight journal articles, two journal letters and 23 congress abstracts were selected on criteria of original real-world evidence with a clinical focus. As expected with real-world evidence, quality scoring showed that the evidence had high external validity but lower internal validity. A total of 13,552 patients were described across nine European countries and all approved SB4 indications: 2499 were ETN-naïve and 11,053 switched from reference ETN to SB4 (switchers). Switch acceptance rates (a combination of clinicians offering and patients accepting initiation on SB4) ranged between 51.6% and 99.0%; patient support programmes positively contributed to acceptance. Disease activity was generally similar pre- and post-switch (typically 3-month timeframe). Retention rates across studies were at least 75% (up to 12 months follow-up). No new safety signals were identified. Differences in discontinuation rates versus historic controls reported in some studies may have been influenced by differences in treatment practices, lack of clinician confidence and nocebo effects. CONCLUSION: Nearly 2500 ETN-naïve patients have been initiated on SB4 and outcomes are similar to those patients receiving reference ETN. Overall this systematic review of real-world evidence provides additional reassurance that SB4 is as effective and safe as reference ETN in both switched and naïve patients. FUNDING: Biogen International GmbH.

4.
High Alt Med Biol ; 19(3): 215-220, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29757001

RESUMEN

Summerfield, Douglas T., Kirsten E. Coffman, Bryan J. Taylor, Amine N. Issa, and Bruce D. Johnson. Exhaled nitric oxide changes during acclimatization to high altitude: a descriptive study. High Alt Med Biol. 19:215-220, 2018. AIMS: This study describes differences in the partial pressures of exhaled nitric oxide (PeNO) between subjects fully acclimatized (ACC) to 5300 m and those who have just arrived to high altitude. METHODS: PeNO was determined in eight subjects newly exposed and nonacclimatized (non-ACC) to high altitude and compared with that in nine subjects who had ACC to high altitude for 1 month. In addition, systolic pulmonary artery pressure (sPAP) and arterial oxygen saturation (SaO2) were measured in all participants. These measurements were repeated in the non-ACC group 5 and 9 days later. RESULTS: PeNO levels on day 1 were significantly higher in the non-ACC versus ACC cohort (8.7 ± 3.5 vs. 3.9 ± 2.2 nmHg, p = 0.004). As the non-ACC group remained at altitude, PeNO levels fell and were not different when compared with those of the ACC group by day 9 (5.9 ± 2.4 vs. 3.9 ± 2.2 nmHg, p = 0.095). Higher sPAP was correlated with lower PeNO levels in all participants (R = -0.50, p = 0.043). PeNO levels were not correlated with SaO2. CONCLUSIONS: As individuals acclimatized to high altitude, PeNO levels decreased. Even after acclimatization, PeNO levels continued to play a role in pulmonary vascular tone.


Asunto(s)
Aclimatación/fisiología , Presión Arterial , Óxido Nítrico/análisis , Oxígeno/sangre , Altitud , Pruebas Respiratorias , Espiración , Femenino , Humanos , Masculino , Presión Parcial , Arteria Pulmonar , Factores de Tiempo
5.
Respir Physiol Neurobiol ; 243: 77-85, 2017 09.
Artículo en Inglés | MEDLINE | ID: mdl-28554819

RESUMEN

We aimed to assess lung fluid balance before and after gradual ascent to 5150m. Lung diffusion capacity for carbon monoxide (DLCO), alveolar-capillary membrane conductance (DmCO) and ultrasound lung comets (ULCs) were assessed in 12 healthy lowlanders at sea-level, and on Day 1, Day 5 and Day 9 after arrival at Mount Everest Base Camp (EBC). EBC was reached following an 8-day hike at progressively increasing altitudes starting at 2860m. DLCO was unchanged from sea-level to Day 1 at EBC, but increased on Day 5 (11±10%) and Day 9 (10±9%) vs. sea-level (P≤0.047). DmCO increased from sea-level to Day 1 (9±6%), Day 5 (12±8%), and Day 9 (17±11%) (all P≤0.001) at EBC. There was no change in ULCs from sea-level to Day 1, Day 5 and Day 9 at EBC. These data provide evidence that interstitial lung fluid remains stable or may even decrease relative to at sea-level following 8days of gradual exposure to high-altitude in healthy humans.


Asunto(s)
Altitud , Presión Arterial/fisiología , Pulmón/irrigación sanguínea , Capacidad de Difusión Pulmonar/fisiología , Adulto , Capilares/fisiología , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Pulmón/diagnóstico por imagen , Pulmón/fisiología , Masculino , Persona de Mediana Edad , Pruebas de Función Respiratoria , Factores de Tiempo , Ultrasonografía , Equilibrio Hidroelectrolítico/fisiología
6.
Wilderness Environ Med ; 27(3): 371-8, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27460198

RESUMEN

OBJECTIVE: It is well documented that cognitive performance may be altered with ascent to altitude, but the association of various cognitive performance tests with symptoms of acute mountain sickness (AMS) is not well understood. Our objective was to assess and compare cognitive performance during a high-altitude expedition using several tests and to report the association of each test with AMS, headache, and quality of sleep. METHODS: During an expedition to Mount Everest, 3 cognitive tests (Stroop, Trail Making, and the real-time cognitive assessment tool, an in-house developed motor accuracy test) were used along with a questionnaire to assess health and AMS. Eight team members were assessed pre-expedition, postexpedition, and at several time points during the expedition. RESULTS: There were no significant differences (P >.05) found among scores taken at 3 time points at base camp and the postexpedition scores for all 3 tests. Changes in the Stroop test scores were significantly associated with the odds of AMS (P <.05). The logistic regression results show that the percent change from baseline for Stroop score (ß = -5.637; P = .032) and Stroop attempts (ß = -5.269; P = .049) are significantly associated with the odds of meeting the criteria for AMS. CONCLUSIONS: No significant changes were found in overall cognitive performance at altitude, but a significant relationship was found between symptoms of AMS and performance in certain cognitive tests. This research shows the need for more investigation of objective physiologic assessments to associate with self-perceived metrics of AMS to gauge effect on cognitive performance.


Asunto(s)
Mal de Altura/diagnóstico , Mal de Altura/psicología , Cognición/fisiología , Montañismo/psicología , Sueño/fisiología , Adulto , Altitud , Mal de Altura/fisiopatología , Cefalea/etiología , Humanos , Persona de Mediana Edad , Montañismo/fisiología , Test de Stroop , Factores de Tiempo
7.
Eur J Appl Physiol ; 116(2): 427-37, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26614507

RESUMEN

PURPOSE: We determined whether well-acclimatized humans have a reserve to recruit pulmonary capillaries in response to exercise at high altitude. METHODS: At sea level, lung diffusing capacity for carbon monoxide (DLCO), alveolar-capillary membrane conductance (DmCO), and pulmonary capillary blood volume (V c) were measured at rest before maximal oxygen consumption ([Formula: see text]) was determined in seven adults. Then, DLCO, DmCO and V c were measured pre- and post-exhaustive incremental exercise at 5150 m after ~40 days of acclimatization. RESULTS: Immediately after exercise at high altitude, there was an increase in group mean DmCO (14 ± 10%, P = 0.040) with no pre- to post-exercise change in group mean DLCO (46.9 ± 5.8 vs. 50.6 ± 9.6 ml/min/mmHg, P = 0.213) or V c (151 ± 28 vs. 158 ± 37 ml, P = 0.693). There was, however, a ~20% increase in DLCO from pre- to post-exercise at high altitude (51.2 ± 0.2 vs. 61.1 ± 0.2 ml/min/mmHg) with a concomitant increase in DmCO (123 ± 2 vs. 156 ± 4 ml/min/mmHg) and V c (157 ± 3 vs. 180 ± 8 ml) in 2 of the 7 participants. There was a significant positive relationship between the decrease in [Formula: see text] from sea level to high altitude and the change in DLCO and lung diffusing capacity for nitric oxide (DLNO) from rest to end-exercise at high altitude. CONCLUSION: These data suggest that recruitment of the pulmonary capillaries in response to exercise at high altitude is limited in most well-acclimatized humans but that any such a reserve may be associated with better exercise capacity.


Asunto(s)
Altitud , Volumen Sanguíneo , Capilares/fisiología , Ejercicio Físico , Pulmón/irrigación sanguínea , Intercambio Gaseoso Pulmonar , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Consumo de Oxígeno , Circulación Pulmonar
8.
Aerosp Med Hum Perform ; 86(2): 76-81, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25946730

RESUMEN

INTRODUCTION: Recent physiological incidents involving pilots of high performance fighter aircraft have raised the question of whether inadvertent, short bursts of significantly reduced oxygen could negatively impact real-time performance. This study evaluated normobaric, real-time performance in the setting of transient near-anoxia to inform future countermeasure development. METHODS: The study was performed on 12 healthy subjects without significant medical history. Following collection of baseline data, real-time performance changes were evaluated during sequentially increasing periods of near-anoxic gas exposure (F(I)0(2) = 1%) using a computer-based performance assessment tool. Both room air and 100% oxygen were used as the prebreathe/recovery gases. Statistical analysis was performed on the results. RESULTS: Under normobaric conditions, subjects inspiring up to five near-anoxic breaths showed no significant performance decrement in either accuracy or effective actions per minute. Mean accuracy up to five near-anoxic breaths was 0.67 (SD = 0.01) as compared to a baseline mean of 0.68 (SD = 0.02). Hyperoxia had a protective effect on subject physiological response to near anoxia. DISCUSSION: These normobaric findings offer an assessment of real-time performance changes in the setting of transient, near-anoxic gas exposure. Overall, the results help inform the design of increasingly complex aircraft oxygen delivery systems in terms of how tightly such systems must match the sea-level gas equivalent with increasing altitude. This is particularly relevant as such systems are being called upon to ensure safe aircrew operations across an expanding operational flight envelope.


Asunto(s)
Medicina Aeroespacial , Cognición/fisiología , Hipoxia/fisiopatología , Análisis y Desempeño de Tareas , Adulto , Altitud , Femenino , Humanos , Hiperoxia/fisiopatología , Masculino , Monitoreo Fisiológico , Oxígeno/administración & dosificación , Recuperación de la Función , Adulto Joven
9.
Sleep ; 38(8): 1331-4, 2015 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-25581919

RESUMEN

STUDY OBJECTIVES: To determine the impact of averaging window-length on the "desaturation" indexes (DIs) obtained via overnight pulse oximetry (SpO2) at high altitude. DESIGN: Overnight SpO2 data were collected during a 10-day sojourn at high altitude. SpO2 was obtained using a commercial wrist-worn finger oximeter whose firmware was modified to store unaveraged beat-to-beat data. Simple moving averages of window lengths spanning 2 to 20 cardiac beats were retrospectively applied to beat-to-beat SpO2 datasets. After SpO2 artifacts were removed, the following DIs were then calculated for each of the averaged datasets: oxygen desaturation index (ODI); total sleep time with SpO2 < 80% (TST < 80), and the lowest SpO2 observed during sleep (SpO2 low). SETTING: South Base Camp, Mt. Everest (5,364 m elevation). PARTICIPANTS: Five healthy, adult males (35 ± 5 y; 180 ± 1 cm; 85 ± 4 kg). INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: 49 datasets were obtained from the 5 participants, totalling 239 hours of data. For all window lengths ≥ 2 beats, ODI and TST < 80 were lower, and SpO2 low was higher than those values obtained from the beat-to-beat SpO2 time series data (P < 0.05). CONCLUSIONS: Our findings indicate that increasing oximeter averaging window length progressively underestimates the frequency and magnitude of sleep disordered breathing events at high altitude, as indirectly assessed via the desaturation indexes.


Asunto(s)
Altitud , Oximetría/métodos , Síndromes de la Apnea del Sueño/diagnóstico , Síndromes de la Apnea del Sueño/fisiopatología , Adulto , Artefactos , Voluntarios Sanos , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Oximetría/instrumentación , Oxígeno/metabolismo , Polisomnografía/instrumentación , Sueño/fisiología , Factores de Tiempo
10.
Breast Cancer Res ; 15(1): R8, 2013 Jan 23.
Artículo en Inglés | MEDLINE | ID: mdl-23343422

RESUMEN

INTRODUCTION: Targeting receptor tyrosine kinases (RTKs) with kinase inhibitors is a clinically validated anti-cancer approach. However, blocking one signaling pathway is often not sufficient to cause tumor regression and the effectiveness of individual inhibitors is often short-lived. As alterations in fibroblast growth factor receptor (FGFR) activity have been implicated in breast cancer, we examined in breast cancer models with autocrine FGFR activity the impact of targeting FGFRs in vivo with a selective kinase inhibitor in combination with an inhibitor of PI3K/mTOR or with a pan-ErbB inhibitor. METHODS: Using 4T1 or 67NR models of basal-like breast cancer, tumor growth was measured in mice treated with an FGFR inhibitor (dovitinib/TKI258), a PI3K/mTOR inhibitor (NVP-BEZ235) or a pan-ErbB inhibitor (AEE788) individually or in combination. To uncover mechanisms underlying inhibitor action, signaling pathway activity was examined in tumor lysates and transcriptome analysis carried out to identify pathways upregulated by FGFR inhibition. Anti-phosphotyrosine receptor antibody arrays (P-Tyr RTK) were also used to screen 4T1 tumors. RESULTS: The combination of dovitinib + NVP-BEZ235 causes tumor stasis and strong down-regulation of the FRS2/Erk and PI3K/Akt/mTOR signaling pathways. P-Tyr RTK arrays identified high levels of P-EGFR and P-ErbB2 in 4T1 tumors. Testing AEE788 in the tumor models revealed that the combination of dovitinib + AEE788 resulted in blockade of the PI3K/Akt/mTOR pathway, prolonged tumor stasis and in the 4T1 model, a significant decrease in lung metastasis. The results show that in vivo these breast cancer models become dependent upon co-activation of FGFR and ErbB receptors for PI3K pathway activity. CONCLUSIONS: The work presented here shows that in the breast cancer models examined, the combination of dovitinib + NVP-BEZ235 or dovitinib + AEE788 results in strong inhibition of tumor growth and a block in metastatic spread. Only these combinations strongly down-regulate the FGFR/FRS2/Erk and PI3K/Akt/mTOR signaling pathways. The resultant decrease in mitosis and increase in apoptosis was consistently stronger in the dovitinib + AEE788 treatment-group, suggesting that targeting ErbB receptors has broader downstream effects compared to targeting only PI3K/mTOR. Considering that sub-classes of human breast tumors co-express ErbB receptors and FGFRs, these results have implications for targeted therapy.


Asunto(s)
Neoplasias de la Mama/genética , Proliferación Celular/efectos de los fármacos , Receptores ErbB/genética , Receptores de Factores de Crecimiento de Fibroblastos/genética , Animales , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Receptores ErbB/antagonistas & inhibidores , Femenino , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Imidazoles/administración & dosificación , Ratones , Terapia Molecular Dirigida , Fosfatidilinositol 3-Quinasas/administración & dosificación , Fosfatidilinositol 3-Quinasas/genética , Inhibidores de Proteínas Quinasas/administración & dosificación , Proteínas Proto-Oncogénicas c-akt/genética , Purinas/administración & dosificación , Quinolinas/administración & dosificación , Receptores de Factores de Crecimiento de Fibroblastos/antagonistas & inhibidores , Transducción de Señal/efectos de los fármacos , Serina-Treonina Quinasas TOR/genética , Ensayos Antitumor por Modelo de Xenoinjerto
11.
Cell Rep ; 1(3): 191-9, 2012 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-22832193

RESUMEN

Tumor expression of the lymphangiogenic factor VEGF-C is correlated with metastasis and poor prognosis, and although VEGF-C enhances transport to the draining lymph node (dLN) and antigen exposure to the adaptive immune system, its role in tumor immunity remains unexplored. Here, we demonstrate that VEGF-C promotes immune tolerance in murine melanoma. In B16 F10 melanomas expressing a foreign antigen (OVA), VEGF-C protected tumors against preexisting antitumor immunity and promoted local deletion of OVA-specific CD8(+) T cells. Naive OVA-specific CD8(+) T cells, transferred into tumor-bearing mice, were dysfunctionally activated and apoptotic. Lymphatic endothelial cells (LECs) in dLNs cross-presented OVA, and naive LECs scavenge and cross-present OVA in vitro. Cross-presenting LECs drove the proliferation and apoptosis of OVA-specific CD8(+) T cells ex vivo. Our findings introduce a tumor-promoting role for lymphatics in the tumor and dLN and suggest that lymphatic endothelium in the local microenvironment may be a target for immunomodulation.


Asunto(s)
Antígenos de Neoplasias/inmunología , Reactividad Cruzada/inmunología , Tolerancia Inmunológica/inmunología , Ganglios Linfáticos/inmunología , Melanoma Experimental/inmunología , Factor C de Crecimiento Endotelial Vascular/metabolismo , Animales , Presentación de Antígeno/inmunología , Apoptosis/inmunología , Linfocitos T CD8-positivos/inmunología , Vacunas contra el Cáncer/inmunología , Células Dendríticas/inmunología , Células Endoteliales/metabolismo , Antígenos de Histocompatibilidad Clase I/inmunología , Ganglios Linfáticos/patología , Linfangiogénesis , Melanoma Experimental/patología , Melanoma Experimental/prevención & control , Ratones , Metástasis de la Neoplasia , Péptidos/inmunología , Células del Estroma/metabolismo
12.
J Comp Neurol ; 518(20): 4213-25, 2010 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-20878784

RESUMEN

The neuregulin (NRG) family of trophic factors is present in the central and peripheral nervous systems and participates in the survival, proliferation, and differentiation of many different cell types, including motoneurons. NRG1 was first characterized by its role in the formation of the neuromuscular junction, and recently it was shown to play a crucial role in modulating glutamatergic and cholinergic transmission in the central nervous system of adult rats. However, little is known about NRG1's role in adult motor systems. Motoneurons receive dense glutamatergic and cholinergic input. We hypothesized that NRG1 is present at synapses on phrenic motoneurons. Confocal microscopy and 3D reconstruction techniques were used to determine the distribution of NRG1 and its colocalization with these different neurotransmitter systems. We found that NRG1 puncta are present around retrogradely labeled motoneurons and are distributed predominantly at motoneuron somata and primary dendrites. NRG1 is present exclusively at synaptic sites (identified using the presynaptic marker synaptophysin), making up ∼30% of all synapses at phrenic motoneurons. Overall, NRG1 immunoreactivity is found predominantly at cholinergic synapses (75% ± 14% colocalize with the vesicular acetylcholine transporter; VAChT). Nearly all (99% ± 1%) VAChT-immunoreactive synapses expressed NRG1. NRG1 also is present at a subset of glutamatergic synapses expressing the vesicular glutamate transporter (VGLUT) type 2 (∼6%) but not those expressing VGLUT type 1. Overall, 26% ± 6% of NRG1 synapses are VGLUT2 immunoreactive. These findings provide the first evidence suggesting that NRG1 may modulate synaptic activity in adult motor systems.


Asunto(s)
Neuronas Motoras/metabolismo , Neurregulina-1/metabolismo , Nervio Frénico/citología , Sinapsis/metabolismo , Acetilcolina/metabolismo , Animales , Ácido Glutámico/metabolismo , Inmunohistoquímica , Masculino , Neuronas Motoras/citología , Ratas , Ratas Sprague-Dawley , Sinapsis/ultraestructura
13.
J Hypertens ; 27(4): 763-8, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19516175

RESUMEN

BACKGROUND: Ambulatory arterial stiffness index (AASI) is a novel estimate of arterial stiffness, which independently predicts cardiovascular mortality, even in normotensive individuals. Additionally, other markers derived from ambulatory blood pressure (BP) monitoring, including variability, pulse pressure, nocturnal dipping, and morning BP surge, have all been shown to be predictive of end-organ damage and cardiovascular disease. Exaggerated cardiovascular reactivity to sympathoexcitatory stimuli may also predict future incidence of hypertension. The purpose of this investigation was to test the hypothesis that AASI and other derivations of ambulatory BP, including pulse pressure, 24-h blood pressure variability, dipping, and morning surge, would be correlated with the pressor response to common physiological stress maneuvers. METHOD: We measured continuous heart rate and arterial BP during head-up tilt, mental stress, cold pressor test, and isometric handgrip to fatigue in 67 healthy, normotensive, nonobese individuals (43 women, 24 men, mean age +/- SD: 28 +/- 6 years). Then, 24-h ambulatory BP was obtained, and AASI was defined as 1 minus the slope of diastolic on systolic BP in individual 24-h ambulatory BP recordings. RESULTS: Although all measures were widely variable among patients, there was no relationship between AASI, pulse pressure, blood pressure variability, dipping, and morning surge with the pressor responses. CONCLUSION: We conclude that in the absence of aging, cardiovascular, or autonomic disease, the novel stiffness index (AASI) or other ambulatory BP indices are either poorly correlated with or mechanistically unrelated to the complex pressor response to common provocations of sympathoexcitation.


Asunto(s)
Arterias/fisiología , Presión Sanguínea , Estrés Fisiológico/fisiología , Estrés Psicológico/fisiopatología , Adulto , Monitoreo Ambulatorio de la Presión Arterial , Frío , Ejercicio Físico/fisiología , Femenino , Frecuencia Cardíaca , Humanos , Masculino
14.
Cancer Res ; 69(1): 349-57, 2009 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-19118020

RESUMEN

Most carcinomas spread to distant sites through lymphatic vessels. Several preclinical and clinical studies have shown a positive correlation between the incidence of lymph node metastasis and secretion of the lymphatic growth factor vascular endothelial growth factor-C (VEGF-C) by tumor cells, suggesting tumor lymphangiogenesis as an escape mechanism. However, recent evidence has shown VEGF receptor-3 (VEGFR-3) expression on tumor cells and autocrine signaling, which increase metastatic potential. Furthermore, there is growing evidence implicating lymphatic-homing chemokine receptors, particularly C-C chemokine receptor 7 (CCR7), in lymph node metastasis. We report here that expressions of VEGF-C and CCR7 by tumor cells act synergistically to promote their invasion toward lymphatics. First, VEGF-C acts to increase lymphatic secretion of CCL21, which in turn drives CCR7-dependent tumor chemoinvasion toward lymphatics. Second, VEGF-C acts in an autocrine fashion to increase tumor invasiveness by increasing the proteolytic activity and motility of tumor cells in a three-dimensional matrix. Both of these effects are VEGFR-3 dependent and evident only in three-dimensional environments. We further verified that VEGF-C induces lymphatic CCL21 up-regulation in vivo by direct injection of VEGF-C protein intradermally in the mouse. Taken together, these results bridge the prometastatic functions of CCR7 and VEGF-C in tumors and show that, beyond lymphangiogenesis, VEGF-C promotes tumor invasion toward lymphatics by both autocrine and CCR7-dependent paracrine signaling mechanisms, which may be a significant cause of lymph node metastasis.


Asunto(s)
Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Células Endoteliales/metabolismo , Células Endoteliales/patología , Receptores CCR7/metabolismo , Factor C de Crecimiento Endotelial Vascular/metabolismo , Línea Celular Tumoral , Movimiento Celular/fisiología , Quimiocina CCL21/metabolismo , Humanos , Metástasis Linfática , Vasos Linfáticos/metabolismo , Invasividad Neoplásica , Receptor Cross-Talk , Receptores CCR7/biosíntesis , Transducción de Señal , Factor C de Crecimiento Endotelial Vascular/biosíntesis , Receptor 3 de Factores de Crecimiento Endotelial Vascular/biosíntesis , Receptor 3 de Factores de Crecimiento Endotelial Vascular/metabolismo
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