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Díaz, Miguel, Högskoleadjunkt
Alternative names
Publications (9 of 9) Show all publications
Díaz, M., Avila, A., Degens, H., Coeckelberghs, E., Vanhees, L., Cornelissen, V. & Azzawi, M. (2019). Acute resveratrol supplementation in coronary artery disease: towards patient stratification. Scandinavian Cardiovascular Journal, 1-20
Open this publication in new window or tab >>Acute resveratrol supplementation in coronary artery disease: towards patient stratification
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2019 (English)In: Scandinavian Cardiovascular Journal, ISSN 1401-7431, E-ISSN 1651-2006, p. 1-20Article in journal (Refereed) Epub ahead of print
Abstract [en]

OBJECTIVE: Resveratrol (RV) is a polyphenol with antioxidant, anti-inflammatory and cardio-protective properties. Our objective was to investigate whether acute supplementation with high doses of RV would improve flow-mediated dilation (FMD) and oxygen consumption (VO2) kinetics in older coronary artery disease (CAD) patients.

DESIGN: We employed a placebo-controlled, single-blind, crossover design in which ten participants (aged 66.6 ± 7.8 years) received either RV or placebo (330 mg, 3x day-1) during three consecutive days plus additional 330 mg in the morning of the fourth day with a seven-day wash-out period in-between. On the fourth day, FMD of the brachial artery and VO2 on-kinetics were determined. Results; RV improved FMD in patients who had undergone coronary artery bypass grafting (CABG; -1.4 vs. 5.0%; p = 0.004), but not in those who had undergone percutaneous coronary intervention (PCI; 4.2 vs. -0.2%; NS).

CONCLUSION: Acute high dose supplementation with RV improved FMD in patients after CABG surgery but impaired FMD in patients who underwent PCI. The revascularization method-related differential effects of RV may be due to its direct effects on endothelial-dependent dilator responses. Our findings have important implications for personalized treatment and stratification of older CAD patients.

Keywords
Aging, Antioxidant, Endothelial Dysfunction, Oxygen Uptake
National Category
Cardiac and Cardiovascular Systems
Identifiers
urn:nbn:se:rkh:diva-3018 (URN)10.1080/14017431.2019.1657584 (DOI)31429599 (PubMedID)
Available from: 2019-08-23 Created: 2019-08-23 Last updated: 2019-08-23Bibliographically approved
Díaz, M., Parikh, V., Ismail, S., Maxamed, R., Tye, E., Austin, C., . . . Azzawi, M. (2019). Differential effects of resveratrol on the dilator responses of femoral arteries, ex vivo. Nitric oxide, 92, 1-10
Open this publication in new window or tab >>Differential effects of resveratrol on the dilator responses of femoral arteries, ex vivo
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2019 (English)In: Nitric oxide, ISSN 1089-8603, E-ISSN 1089-8611, Vol. 92, p. 1-10Article in journal (Refereed) Published
Abstract [en]

Resveratrol is a plant-derived phytoalexin with antioxidant, anti-inflammatory and cardio-protective properties and may be a promising therapeutic intervention strategy in cardiovascular disease. Here, we investigated the acute direct effects of trans-resveratrol (RV), on acetylcholine (ACh)-induced and flow-mediated dilation (FMD) of isolated pressurized femoral arteries of young (4-month-old) and old (26-month-old) mice. Vessel exposure to RV enhanced ACh (0.01-1.0 mM)-induced dilation (p < 0.05), but not FMD (@ 5-10 μL⋅min-1) (p < 0.05) in both young and old mice. After RV incubation, acute nitric oxide (NO) production by cultured endothelial cells was increased in response to 0.01 mM ACh, but reduced by flow (5-10 μL⋅min-1; p < 0.05). In isolated femoral arteries from endothelial nitric oxide synthase knockout (eNOS-/-) mice, RV had no overall effect on flow mediated dilation, but potentiated ACh induced dilation, that was completely abolished by potassium channel blockers, Apamin and Tram 34 (p < 0.01). We demonstrate that the non-metabolised form of RV stimulates ACh-induced dilation via the NO and EDHF pathways, but not FMD by interaction with the cyclo-oxygenase pathway. Our findings have important implications in the use of RV (for both young and aged) under 'normal' non-diseased physiological states.

Place, publisher, year, edition, pages
Elsevier, 2019
Keywords
Ageing, Endothelial function, Flow, Nitric oxide, Pressure myography, Resveratrol
National Category
Medical Biotechnology
Identifiers
urn:nbn:se:rkh:diva-3009 (URN)10.1016/j.niox.2019.07.008 (DOI)31369814 (PubMedID)
Available from: 2019-08-08 Created: 2019-08-08 Last updated: 2019-08-08Bibliographically approved
Díaz, M., Degens, H., Vanhees, L., Austin, C. & Azzawi, M. (2016). The effects of resveratrol on aging vessels. Experimental Gerontology, 85(1), 41-47
Open this publication in new window or tab >>The effects of resveratrol on aging vessels
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2016 (English)In: Experimental Gerontology, ISSN 0531-5565, E-ISSN 1873-6815, Vol. 85, no 1, p. 41-47Article, review/survey (Refereed) Published
National Category
Health Sciences
Identifiers
urn:nbn:se:rkh:diva-2793 (URN)10.1016/j.exger.2016.09.016 (DOI)
Available from: 2019-04-09 Created: 2019-04-09 Last updated: 2019-04-23Bibliographically approved
Díaz, M. M. (2015). Chronic stress induces a hyporeactivity of the autonomic nervous system in response to acute mental stressor and impairs cognitive performance in business executives. PLoS ONE, 10(3), Article ID e0119025.
Open this publication in new window or tab >>Chronic stress induces a hyporeactivity of the autonomic nervous system in response to acute mental stressor and impairs cognitive performance in business executives
2015 (English)In: PLoS ONE, Vol. 10, no 3, article id e0119025Article in journal (Refereed) Published
Abstract [en]

The present study examined the incidence of chronic stress in business executives (109 subjects: 75 male and 34 female) and its relationship with cortisol levels, cognitive performance, and autonomic nervous system (ANS) reactivity after an acute mental stressor. Blood samples were collected from the subjects to measure cortisol concentration. After the sample collection, the subjects completed the Lipp Inventory of Stress Symptoms for Adults and the Stroop Color-Word Test to evaluate stress and cognitive performance levels, respectively. Saliva samples were collected prior to, immediately after, and five minutes after the test. The results revealed that 90.1% of the stressed subjects experienced stress phases that are considered chronic stress. At rest, the subjects with chronic stress showed higher cortisol levels, and no gender differences were observed. No differences were found between the stressed and non-stressed subjects regarding salivary amylase activity prior to test. Chronic stress also impaired performance on the Stroop test, which revealed higher rates of error and longer reaction times in the incongruent stimulus task independently of gender. For the congruent stimulus task of the Stroop test, the stressed males presented a higher rate of errors than the non-stressed males and a longer reaction time than the stressed females. After the acute mental stressor, the non-stressed male group showed an increase in salivary alpha-amylase activity, which returned to the initial values five minutes after the test; this ANS reactivity was not observed in the chronically stressed male subjects. The ANS responses of the non-stressed vs stressed female groups were not different prior to or after the Stroop test. This study is the first to demonstrate a blunted reactivity of the ANS when male subjects with chronic psychological stress were subjected to an acute mental stressor, and this change could contribute to impairments in cognitive performance.

Keywords
Psychological stress, Cortisol, Stroop test, Cognitive impairment, Executives, Catecholamines, Reaction time, Saliva
National Category
Medical and Health Sciences Psychology
Identifiers
urn:nbn:se:rkh:diva-2787 (URN)10.1371/journal.pone.0119025 (DOI)
Note

Funding: This study was supported by grants from the funding agency FAPEMIG (Fundação de Amparo à Pesquisa do Estado de Minas Gerais - grant nº. APQ 01347/08). TVSS, MMD, and OLB received graduate fellowships from CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Available from: 2019-04-04 Created: 2019-04-04 Last updated: 2019-04-05Bibliographically approved
Díaz, M. M., Bocanegra, O. L., Teixeira, R. R., Soares, S. S. & Espindola, F. S. (2013). Salivary nitric oxide and alpha-amylase as indexes of training intensity and load. International Journal of Sports Medicine, 34(1), 8-13
Open this publication in new window or tab >>Salivary nitric oxide and alpha-amylase as indexes of training intensity and load
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2013 (English)In: International Journal of Sports Medicine, ISSN 0172-4622, E-ISSN 1439-3964, Vol. 34, no 1, p. 8-13Article in journal (Refereed) Published
Abstract [en]

This study examined the variation in salivary nitric oxide (NO), alpha-amylase (sAA) and serum markers of muscle injury during 21 weeks of training in elite swimmers. Samples of saliva and blood were collected once a month during 5 months from 11 male professional athletes during their regular training season. The variation in each marker throughout the 21 weeks was compared with the dynamics of trainingvolume, intensity and load. Unstimulated whole saliva was assessed for NO and sAA whereas venous blood was assessed for lactate dehydrogenase, creatine kinase, and γ-glutamyltransferase. Nitric oxide and sAA showed a proportional response to the intensity of training. However, whereas the concentration of NO increased across the 21 weeks, the activity of sAA decreased. Similar variations in the concentration of NO and the markers of muscle injury were also observed. The higher concentration of NO might be attributed to changes in haemodynamics and muscle regenerative processes. On the other hand, autonomic regulation towards parasympathetic predominance might have been responsible for the decrease in sAA activity. These findings provide appealing evidence for the utilization of salivary constituents in sports medicine to monitor training programmes.

National Category
Health Sciences
Identifiers
urn:nbn:se:rkh:diva-2792 (URN)10.1055/s-0032-1316318 (DOI)22960992 (PubMedID)
Available from: 2019-04-09 Created: 2019-04-09 Last updated: 2019-04-17Bibliographically approved
Díaz, M., Bocanegra Jaramillo, O., Teixeira, R. & Espindola, F. S. (2013). Salivary surrogates of plasma nitrite and catecholamines during a 21-week training season in swimmers. PLoS ONE, 21(8), Article ID 5.
Open this publication in new window or tab >>Salivary surrogates of plasma nitrite and catecholamines during a 21-week training season in swimmers
2013 (English)In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 21, no 8, article id 5Article in journal (Refereed) Published
Abstract [en]

The collection of samples of saliva is noninvasive and straightforward, which turns saliva into an ideal fluid for monitoring the adaptive response to training. Here, we investigated the response of the salivary proteins alpha-amylase (sAA), chromogranin A (sCgA), and the concentration of total protein (sTP) as well as salivary nitrite (sNO2) in relation to plasma catecholamines and plasma nitrite (pNO2), respectively. The variation in these markers was compared to the intensity and load of training during a 21-week training season in 12 elite swimmers. Overall, the salivary proteins tracked the concentration of plasma adrenaline and were inversely correlated with the training outcomes. No correlations were observed between sNO2 and pNO2. However, sNO2 correlated positively with the intensity and load of training. We argue that the decrease in sympathetic activity is responsible for the decrease in the concentration of proteins throughout the training season. Furthermore, the increase in nitrite is likely to reflect changes in hemodynamics and regulation of vascular tone. The association of the salivary markers with the training outcomes underlines their potential as noninvasive markers of training status in professional athletes.

National Category
Health Sciences
Identifiers
urn:nbn:se:rkh:diva-2794 (URN)10.1371/journal.pone.0064043 (DOI)23700456 (PubMedID)
Available from: 2019-04-09 Created: 2019-04-09 Last updated: 2019-04-10Bibliographically approved
Díaz, M. M., Bocanegra, O. L., Teixeira, R. R., Tavares, M., Soares, S. S. & Espindola, F. S. (2013). The relationship between the cortisol awakening response, mood states, and performance. Journal of Strength and Conditioning Research, 27(5), 1340-1348
Open this publication in new window or tab >>The relationship between the cortisol awakening response, mood states, and performance
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2013 (English)In: Journal of Strength and Conditioning Research, ISSN 1064-8011, E-ISSN 1533-4287, Vol. 27, no 5, p. 1340-1348Article in journal (Refereed) Published
National Category
Health Sciences
Identifiers
urn:nbn:se:rkh:diva-2795 (URN)10.1519/JSC.0b013e318267a612 (DOI)22836604 (PubMedID)
Available from: 2019-04-09 Created: 2019-04-09 Last updated: 2019-04-23Bibliographically approved
Bocanegra, O. L., Díaz, M. M., Teixeira, R. R., Soares, S. S. & Espindola, F. S. (2012). Determination of the lactate threshold by means of salivary biomarkers: chromogranin A as novel marker of exercise intensity. European Journal of Applied Physiology, 112(9), 3195-3203
Open this publication in new window or tab >>Determination of the lactate threshold by means of salivary biomarkers: chromogranin A as novel marker of exercise intensity
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2012 (English)In: European Journal of Applied Physiology, ISSN 1439-6319, E-ISSN 1439-6327, Vol. 112, no 9, p. 3195-3203Article in journal (Refereed) Published
Keywords
Lactate threshold, Saliva, Alpha-amylase, Chromogranin A, Swimming
National Category
Health Sciences
Identifiers
urn:nbn:se:rkh:diva-2791 (URN)10.1007/s00421-011-2294-4 (DOI)22227853 (PubMedID)
Available from: 2019-04-09 Created: 2019-04-09 Last updated: 2019-04-23Bibliographically approved
Díaz, M., Bocanegra, O. L., Teixeira, R. R. & Espindola, F. S. (2012). Response of salivary markers of autonomic activity to elite competition. International Journal of Sports Medicine, 33(9), 763-768
Open this publication in new window or tab >>Response of salivary markers of autonomic activity to elite competition
2012 (English)In: International Journal of Sports Medicine, ISSN 0172-4622, E-ISSN 1439-3964, Vol. 33, no 9, p. 763-768Article in journal (Refereed) Published
Abstract [en]

We investigated the response of salivary total protein (TP), alpha-amylase (sAA) and chromogranin A (CgA) to sporting competition and their relation with positive and negative affect. 11 professional swimmers were examined during the first day of a national contest and on a recreated event that matched time-of-the-day and day-of-the-week assessments 2 weeks later. Total protein was determined by the Bradford method and sAA and CgA by Western blotting upon awakening, 30 and 60 min post awakening, immediately before warming up for competition and 5, 20 and 60 min after competition. Psychometric instruments included the Positive Affect and Negative Affect Schedule-X. The concentrations of TP, sAA and CgA differed from controls only prior to and 5 min after the event. We observed positive correlations between higher negative affect scores with higher levels of TP, sAA and CgA prior to the event on the competition day. All 3 markers showed a similar reactivity to sporting competition, which may be attributed to the mechanisms responsible for protein secretion into saliva when collection is performed with no exogenous stimulation. TP is an attractive marker in sports psychology since its determination is faster and cheaper than traditional kinetic or immune assays.

National Category
Health Sciences
Identifiers
urn:nbn:se:rkh:diva-2796 (URN)10.1055/s-0032-1304638 (DOI)22581684 (PubMedID)
Available from: 2019-04-09 Created: 2019-04-09 Last updated: 2019-04-17Bibliographically approved
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