Percorrer por autor "Antunes, Eduardo"
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- Effects of low-frequency noise on cardiac collagen and cardiomyocyte ultrastructure: an immunohistochemical and electron microscopy studyPublication . Antunes, Eduardo; Borrecho, Gonçalo; Oliveira, Pedro; Matos, António P. Alves de; Brito, José; Águas, Artur; Martins dos Santos, José"Introduction: Low-frequency noise (LFN) leads to the development of tissue fibrosis. We previously reported the development of myocardial and perivascular fibrosis and a reduction of cardiac connexin43 in rats, but data is lacking concerning the affected type of collagen as well as the ultrastructural myocardial modifications. Objectives: The aim of this study was to quantify cardiac collagens I and III and to evaluate myocardial ultrastructural changes in Wistar rats exposed to LFN. Methods: Two groups of rats were considered: A LFN-exposed group with 8 rats continuously submitted to LFN during 3 months and a control group with 8 rats. The hearts were sectioned and the mid-ventricular fragment was selected. After immunohistochemical evaluation, quantification of the collagens and muscle were performed using the image J software in the left ventricle, interventricular septum and right ventricle and the collagen I/muscle and collagen III/muscle ratios were calculated. Transmission electron microscopy (TEM) was used to analyze mid-ventricular samples taken from each group. Results: The collagen I/muscle and collagen III/muscle ratios increased in totum respectively 80% (p<0.001) and 57.4% (p<0.05) in LFN-exposed rats. TEM showed interstitial collagen deposits and changes in mitochondria and intercalated discs of the cardiomyocytes in LFN-exposed animals. Conclusions: LFN increases collagen I and III in the extracellular matrix and induces ultrastructural alterations in the cardiomyocytes. These new morphological data open new and promising paths for further experimental and clinical research regarding the cardiac effects of low-frequency noise."
- Histomorphometric evaluation of the small coronary arteries in rats exposed to industrial noisePublication . Lousinha, Ana; Antunes, Eduardo; Borrecho, Gonçalo; Oliveira, Maria João; Brito, José; Martins dos Santos, JoséMorphological changes induced by industrial noise (IN) have been experimentally observed in several organs. Histological observations of the coronary arteries showed prominent perivascular tissue and fibrosis among IN-exposed rats. The effects on the small arteries are unknown. Objective: To evaluate the histomorphometric changes induced by IN on rat heart small arteries. Methods: Twenty Wistar rats exposed to IN during a maximum period of seven months and 20 age-matched controls were studied. Hearts were transversely sectioned from ventricular apex to atria and a mid-ventricular fragment was selected for analysis. The histological images were obtained with an optical microscope using 400× magnifications. A total of 634 arterial vessels (298 IN-exposed and 336 controls) were selected. The mean lumen-to-vessel wall (L/W) and mean vessel wall-to-perivascular tissue (W/P) ratios were calculated using image J software. Results: There were no differences between exposed and control animals in their L/W ratios (p = 0.687) and time variations in this ratio were non-significant (p = 0.110). In contrast, exposed animals showed lower W/P ratios than control animals (p < 0.001), with significant time variations (p = 0.004). Conclusions: Industrial noise induced an increase in the perivascular tissue of rat small coronary arteries, with significant development of periarterial fibrosis.
- Immunohistochemical evaluation of cardiac connexin43 in rats exposed to low-frequency noisePublication . Antunes, Eduardo; Borrecho, Gonçalo; Oliveira, Pedro; Brito, José; Águas, Artur; Martins dos Santos, José"Introduction: Low-frequency noise (LFN) leads to an abnormal proliferation of collagen and development of tissue fibrosis. It has been shown that myocardial fibrosis in association with gap junction remodeling occurs in several cardiac diseases and can be implicated in the development of ventricular tachyarrhythmias. We previously reported a strong development of myocardial fibrosis induced by LFN in rats but it is not known whether LFN induces any modification on cardiac connexin43 (Cx43). Objectives: The aim of this study was to evaluate modifications on cardiac Cx43 induced by LFN in Wistar rats. Methods: Two groups of rats were considered: A LFN-exposed group with 10 rats submitted continuously to LFN during 3 months and a control group with 8 rats. The hearts were sectioned from the ventricular apex to the atria and the mid-ventricular fragment was selected. The immunohistochemical evaluation of Cx43 was performed using the polyclonal antibody connexin-43m diluted 1:1000 overnight at 4°C. Quantifications of Cx43 and muscle were performed with the image J software and the ratio Cx43/muscle was analyzed in the left ventricle, interventricular septum and right ventricle. Results: The ratio Cx43/muscle was significantly reduced in LFN-exposed rats (p=0.001). The mean value decreased 46.2%, 22.2% and 55.6% respectively in the left ventricle (p=0.008), interventricular septum (p=0.301) and right ventricle (p=0.004). Conclusions: LFN induces modifications on cardiac Cx43 in rats. The Cx43 reduction observed in our study suggests that LFN may induce an arrhythmogenic substrate and opens a new investigational area concerning the effects of LFN on the heart."
- Infrasound exposure promotes development of atrial fibrosis in ratsPublication . Lousinha, Ana; Oliveira, Maria João R.; Borrecho, Gonçalo; Brito, José; Oliveira, Pedro; Pereira, Gonçalo; Carvalho, António Oliveira de; Freitas, Diamantino; Águas, Artur P.; Antunes, Eduardo
- Infrasound induces coronary perivascular fibrosis in ratsPublication . Lousinha, Ana; Oliveira, Maria João R.; Borrecho, Gonçalo; Brito, José; Oliveira, Pedro; Carvalho, António Oliveira de; Freitas, Diamantino; Águas, Artur P.; Antunes, EduardoBACKGROUND: Chronic exposure to industrial noise is known to affect biological systems, namely, by inducing fibrosis in the absence of inflammatory cells. In rat hearts exposed to this environmental hazard, we have previously found myocardial and perivascular fibrosis. The acoustic spectrum of industrial environments is particularly rich in high-intensity infrasound (<20 Hz), whose effects on the heart are unknown. We evaluated the morphological changes induced by IFS in rat coronaries in the presence and absence of dexamethasone. METHODS: Adult Wistar rats were divided into three groups: group A (GA)-IFS (<20 Hz, 120 dB)-exposed rats for 28 days treated with dexamethasone; group B (GB)-IFS-exposed rats; group C (GC)-age-matched controls. The midventricle was prepared for observation with an optical microscope using 100× magnification. Thirty-one arterial vessels were selected (GA 8, GB 10, GC 13). The vessel caliber, thickness of the wall, and perivascular dimensions were quantified using image J software. Mann-Whitney and Kruskal-Wallis tests were used to compare the groups for lumen-to-vessel wall (L/W) and vessel wall-to-perivascular tissue (W/P) ratios. RESULTS: IFS-exposed rats exhibited a prominent perivascular tissue. The median L/W and median W/P ratios were 0.54 and 0.48, 0.66 and 0.49, and 0.71 and 0.68, respectively, in GA, GB, and GC. The W/P ratio was significantly higher in GC compared with IFS-exposed animals (P=.001). The difference was significant between GC and GB (P=.008) but not between GC and GA. CONCLUSION: IFS induces coronary perivascular fibrosis that differs under treatment with corticosteroid.
- Raising awareness and early detection of atrial fibrillation, an experience resorting to mobile technology centred on informed individualsPublication . Cunha, Sara; Antunes, Eduardo; Antoniou, Sotiris; Tiago, Sália; Relvas, Rui; Fernandez-Llimós, Fernando; Costa, Filipa Alves daBackground: Atrial fibrillation (AF) is a cardiac arrhythmia responsible for one third of ischemic strokes. Early detection of AF plays an important role in preventing embolic stroke. Objectives: This study aimed to test the feasibility of an awareness event including opportunistic screening for atrial fibrillation; and to test the reliability of the innovative portable electrocardiogram (ECG) device used. Methods: An awareness campaign was held during two weeks, where individuals consenting to participate in a pharmacist-led detection event, received a manual pulse check, were clinically evaluated and subject to a single-lead electrocardiogram using AliveCor Kardia® mobile. ECGs highlighted as possible AF were confirmed by the cardiologist and those signalled with abnormalities in cardiac rhythm were referred to their physician. Data were collected in a password protected application and analyzed using SPSS, v.24. The Kardia® mobile's sensitivity and specificity was tested against the standard 12-lead ECG. Results: The awareness event involved 223 individuals, among which 205 were screened. Mean age was 66 years (SD = 15) and hypertension was the most frequently reported (n = 107; 52.2%). Mean CHAD2DS2- VASc score was 3 (SD = 1.8). Cardiac irregularities were identified in 45 individuals, 14 confirmed to be new cases of AF (6.8%) by the cardiologist. The sensitivity and specificity were 90.9% and 97.4%. Conclusion: Data suggests this device to be potentially useful for opportunistic early detection of AF, provided interprofessional collaboration is guaranteed so that suspect cases are adequately managed and in a timely way. Fourteen new cases of AF were identified in the population studied, suggesting the pharmacist working in a multiprofessional context, may have had an important role in preventing potential ischemic-related strokes with this initiative. All healthcare professionals involved in the patient pathway should play a more active role in contributing to better health outcomes, particularly within primary care.