Early Estrogen Replacement Therapy Attenuates Cardiac Dysfunction Caused by Aging and Ovariectomy in Female Wistar Rats.

BACKGROUND: Cardiovascular diseases (CVDs) are the leading cause of women's mortality, linked to aging and reduced estrogen during menopause. Estrogen replacement therapy (ERT) is suggested for CVDs prevention. Yet, its timing initiation remains contentious. Thus, we aimed to evaluate the effect of early and late estrogen therapy on cardiac function and lipid metabolism in ovariectomized old female Wistar rats. METHODS: Fifty randomized female Wistar rats were included in 5 groups (n = 10, 18 months old): (1) Sham, (2) 10 weeks post ovariectomy (Ovx-10 w), (3) 10 weeks post Ovx + early estrogen replacement therapy (Ovx 10 w-early ERT), (4) 20 weeks post Ovx (Ovx-20 w) and (5) Ovx 20 w-late ERT. Three days (early ERT) or 10 weeks (late ERT) after surgery 17-ß estradiol was given (5 µg/kg/day), and 10 weeks after the start of ERT, we assessed cardiac function by echocardiography, electrocardiography, and cardiac catheterization. Estradiol, cholesterol, triglyceride (TG), high-density lipoprotein (HDL) and low-density lipoprotein (LDL) levels were determined. Cardiac histology was performed with Masson's staining. RESULTS: Ovariectomy (Ovx) increases left ventricle internal systolic diameter (0.4 vs 0.3 cm, *p = 0.020) and decreases shortening fraction (40 vs 54 %, *p = 0.030) regardless of therapy. ERT prevents the increase in left ventricle mass after 10 weeks post-Ovx and the ejection fractionreduction after 20 weeks. Lower P wave amplitudes (18.8 vs 24.2 ms, *p = 0.013) were found in the Ovx-20 w group. A longer duration of the QRS complex after 20 weeks post-Ovx with and without ERT was found (32.5 and 32.1 vs 28.3 ms, *p = 0.003; *p = 0.007). Diastolic blood pressure was higher 20 weeks post-Ovx (86 vs 76 mmHg, *p = 0.047), regardless of ERT. The left ventricle (LV) -dP/dt was decreased in Ovx groups without ERT (-750 vs -1320 mmHg, *p = 0.034). An increase in LV collagen deposition was found in the Ovx 10 w group vs Sham (9.58 vs 4.54 %, *p = 0.028). Early ERT avoids the increase in body weight, cholesterol and LDL caused by Ovx. CONCLUSIONS: Ovariectomy causes time-dependent alterations in lipid metabolism, morphology, electrical activity, and heart contractile function. Early but not late ERT prevents some of these effects.

Timing Matters: Effects of Early and Late Estrogen Replacement Therapy on Glucose Metabolism and Vascular Reactivity in Ovariectomized Aged Wistar Rats.

Cardiovascular disease incidence increases after menopause due to the loss of estrogen cardioprotective effects. However, there are conflicting data regarding the timing of estrogen therapy (ERT) and its effect on vascular dysfunction associated with impaired glucose metabolism. The aim of this work was to evaluate the effect of early and late ERT on blood glucose/insulin balance and vascular reactivity in aged ovariectomized Wistar rats. Eighteen-month-old female Wistar rats were randomized as follows: (1) sham, (2) 10-week postovariectomy (10 w), (3) 10 w postovariectomy+early estradiol therapy (10 w-early E2), (4) 20-week postovariectomy (20 w), and (5) 20-week postovariectomy+late estradiol therapy (20 w-late E2). Early E2 was administered 3 days after ovariectomy and late therapy after 10 weeks, in both groups. 17ß-Estradiol (E2) was administered daily for 10 weeks (5 µg/kg/day). Concentration-response curves to angiotensin II, KCl, and acetylcholine (ACh) were performed. Heart rate (HR), diastolic and systolic blood pressure (DBP and SBP), glucose, insulin, HOMA-IR, and nitric oxide (NO) levels were determined. Higher glucose levels were found in all groups compared to the sham group, except the 20 w-late E2 group. Insulin was increased in all ovariectomized groups compared to sham. The HOMA-IR index showed insulin resistance in all ovariectomized groups, except for the 10 w-early E2 group. The 10 w-early E2 group increased NO levels vs. the 10 w group. After 10 w postovariectomy, the vascular response to KCl and Ach increases, despite early E2 administration. Early and late E2 treatment decreased vascular reactivity to Ang II. At 20-week postovariectomy, DBP increased, even with E2 administration, while SBP and HR remained unchanged. The effects of E2 therapy on blood glucose/insulin balance and vascular reactivity depend on the timing of therapy. Early ERT may provide some protective effects on insulin resistance and vascular function, whereas late ERT may not have the same benefits.

Which training methods are effective for learning new smartphone memory apps after acquired brain injury? A pilot randomized controlled trial comparing trial and error, systematic instruction and error-based learning.

This study aimed to compare the efficacy of three skills training methods (Trial and error TEL; systematic instruction SI; and error-based learning EBL) for training the use of a smartphone reminder app in individuals with an acquired brain injury. Participants (N = 38, Mage = 61.21 years, 71.1% stroke) were randomly allocated to one of three training conditions and trained over one two-hour session. Proficiency of performance with the trained app (primary outcome) was assessed immediately post-training, one- and six-weeks post-intervention. Secondary outcomes included generalization of skills, error commission, smartphone use frequency and confidence, and subjective memory complaints. Proficiency with the trained app after TEL was higher than SI immediately after the training (d = 0.87) and EBL at the one-week follow-up (d = 0.98). No differences were found six-weeks post-training. Smartphone use confidence increased at the six-week follow-up after TEL (d = 1.12) and EBL training (d = 0.91) but not after SI (d = 0.26). Self-reported memory complaints decreased across time for all groups (ηp2 = 0.30). There was no clearly superior training method for optimizing proficiency with the reminder app. The expected benefits of SI and EBL may not have emerged due to the single-session format of the training. However, smartphone training via TEL or EBL has the potential to address confidence-related barriers to smartphone use.

The experience and acceptability of smartphone reminder app training for people with acquired brain injury: a mixed methods study.

Smartphones are useful compensatory memory aids, yet training on how to use them is seldom offered as part of rehabilitation for acquired brain injuries (ABIs). We aimed to explore the experience and acceptability of a smartphone training intervention in 26 people with ABI who participated in a pilot randomized controlled trial comparing three skills training approaches. Participants completed questionnaire ratings and a semi-structured interview, six weeks post-training. Most participants rated the training as enjoyable (80.8%) and reasonable in duration (88.5%). Others reported that more than one training session was needed to learn the app (34.6%). Five themes were identified from qualitative data through thematic analysis: (1) Attitudes and pre-existing factors, (2) Experiencing the intervention, (3) Tailoring the intervention to the individual, (4) Facilitators and barriers to implementation and (5) Enhancing smartphone use in everyday life. These themes were juxtaposed with a theoretical framework of acceptability, which indicated that some elements (e.g., having a structured session and a supportive trainer) contributed to the acceptability of the intervention by minimizing training burden and increasing self-efficacy. Tailoring the training to the individual's technological skills and lifestyle, providing post-training resources and involving family members were identified as factors that could improve intervention acceptability.

Estrous cycle phase affects myocardial infarction through reactive oxygen species and nitric oxide.

INTRODUCTION: Myocardial infarction is the leading cause of death in women worldwide. Several studies have shown that estrogens play a cardioprotective role in women by decreasing reactive oxygen species (ROS) and increasing nitric oxide (NO). The aim of this work was to determine whether the evolution of myocardial infarction depends on the phase of the estrous cycle. METHODS: Female Wistar rats were randomized into the following groups with an (n = 7 per group): (1) ovariectomized (OVX-sham); (2) OVX-48 h coronary occlusion (CO); (3) OVX-2 w CO; (4) proestrus-sham; (5) proestrus-48 h CO; (6) proestrus-2 w CO; (7) estrus-sham; (8) estrus-48 h CO; and (9) estrus-2 w CO. We measured the percentage of myocardial necrosis, cardiac hypertrophy, hemodynamic parameters, and the production of NO and ROS, after acute and chronic myocardial infarction was induced in proestrus or estrus or ovariectomized female rats. RESULTS: The infarct area was reduced in the proestrus groups, while it was increased in the estrus and OVX groups. The left ventricular systolic pressure (LVSP) and ± dP/dt were reduced, but left ventricular diastolic pressure (LVDP) was increased in the OVX groups. NO was increased in the OVX + CO and estrus + CO groups. Production of ROS was increased in OVX rats after myocardial infarction but remained unchanged in proestrus and estrus. CONCLUSION: The phase of the estrous cycle in which the myocardial infarction occurs is important. When the coronary occlusion occurs during the proestrus phase, it prevents changes in cardiac function, the development of hypertrophy, oxidative stress and changes in NO levels, and reduces the extent of infarction.

The α1D-adrenoreceptor antagonist BMY 7378 reverses cardiac hypertrophy in spontaneously hypertensive rats.

OBJECTIVE: The α1D-adrenoreceptor (α1D-AR) is involved in angiotensin II-induced vascular remodeling and hypertension. Whether α1D-AR plays a role in hypertension-associated cardiac hypertrophy is unclear. Here we investigated effects of BMY 7378, a selective α1D-AR antagonist, on cardiac status in aged spontaneously hypertensive rats (SHR). METHODS: Male SHR were studied during the phase of developing hypertension (5 and 10 weeks old) and once hypertension was established (20 and 30 weeks old) to assess the evolution of cardiac hypertrophy. Age-matched WKY rats were studied as controls. Thirty-week-old SHR were treated for 4 weeks with BMY 7378 (10 mg/kg per day, o.a.), or captopril (angiotensin-converting enzyme inhibitor, 40 mg/kg per day, o.a.) (as a positive control). Blood pressure and cardiac function were measured in vivo, cardiac hypertrophy by histology, and α1D-AR protein expression by immunofluorescence. RESULTS: By 30 weeks of age, SHR exhibited significant hypertension and cardiac hypertrophy. BMY 7378 and captopril decreased blood pressure and improved hemodynamic parameters and cardiac function in treated SHR vs. untreated SHR (P < 0.05). Histology showed increased cardiomyocyte size, fibrosis, and left ventricular hypertrophy in SHR hearts. BMY 7378 ameliorated fibrosis and cardiac hypertrophy, but had no effect on cardiomyocyte size in SHR. Effects of BMY 7378 were associated with increased α1D-AR protein expression in SHR. CONCLUSION: Our data indicate that pharmacological antagonism of α1D-AR reduces blood pressure and associated cardiac hypertrophy in aged SHR. These findings suggest that the α1D-AR plays a pathophysiological role in the development of hypertension and cardiac target organ damage in SHR.

Sex Differences in Vascular Reactivity to Angiotensin II During the Evolution of Myocardial Infarction.

The influence of sex on the vascular response during the progression of myocardial infarction (MI) has not been extensively studied. In this work, we analyzed the differences of the vasoconstriction induced by angiotensin II (Ang II) in the absence and presence of valsartan (200 nM) on the aortic rings of male and female Wistar rats at 2, 4, 24, and 48 hours and 1, 2, 3, and 4 weeks after induction of MI. In the aortic rings of males, an increase was observed in the contractile response that lasts up to 4 weeks; on females, this effect is diminished since 48 hours until reaching sham group values at 2 weeks of coronary occlusion. The incubation of valsartan generated greater reduction on vasoconstriction in males than females. In relation to the determination of infarct areas, we found them between 30% and 40% in all experimental groups. In addition, the index of hypertrophy was determined and no significant changes were observed in female rats, while in males we reported an increase at 2, 3, and 4 weeks. In conclusion, we found differences in vascular reactivity due to sex, as well as on the response of Ang II via AT1 during the evolution of MI.

Percepción de riesgo y compras por internet: su relación con la personalidad y el tipo de Producto / Risk perception and on-line shopping: their relationship with personality and product type

Teniendo en cuenta que el comportamiento del consumidor implica la toma de riesgo y que hay escasez de estudios específicos al contexto de compras por Internet que traten de incorporar los dos principales enfoques con los que se ha estudiado la toma de riesgo, el presente trabajo buscó determinar la relación existente entre los factores de personalidad, el tipo de producto (factor situacional), la percepción de riesgo y la intención y realización de compras por Internet. Para esto se diseñó una encuesta online que contenía situaciones hipotéticas a propósito del comercio electrónico y escalas de medición de factores de personalidad y de percepción de riesgo. Los participantes fueron personas de un rango de edad amplio, parte de una muestra por conveniencia. Se realizó un análisis correlacional de las variables de interés y se encontró que el género, la familiaridad, el factor de personalidad de escrupulosidad y los productos intangibles se relacionan significativamente con la percepción de riesgo general. Los factores de personalidad no parecen ser significativos a la hora de determinar la intención y realización de compras por Internet, brindando así apoyo al enfoque situacional.

Consumer behavior involves risk taking but there are few studies related to electronic commerce that integrate the two main approaches to study risk taking. The present study sought to determine the relationship between personality factors, product type (situational factor), risk perception and the intention and execution of internet shopping. An online survey containing hypothetical scenarios and scales measuring personality factors and risk perception was developed. Participants were individuals of a wide age range, from a convenience sample. A correlational analysis of the variables of interest was performed and it was found that gender, familiarity, conscientiousness personality factor and intangible products are significantly related to the perception of overall risk. Personality factors do not appear to be significant in determining the intention and execution of internet shopping, thus providing support for the situational approach.