Investigating feedforward neural regulation of circulation from analysis of spontaneous arterial pressure and heart rate fluctuations in conscious rats.

Investigating feedforward neural regulation of circulation from analysis of spontaneous arterial pressure and heart rate fluctuations in conscious rats. Am J Physiol Heart Circ Physiol 296: H202–H210, 2009. First published November 14, 2008; doi:10.1152/ajpheart.00358.2008.—It has been suggested in anesthetized animals that the occurrence of sequences of consecutive beats characterized by systolic arterial pressure (SAP) and RR or pulse interval (PI) changing in the opposite direction (SAP /RR and SAP /RR , nonbaroreflex sequences) might represent the expression of neural cardiovascular regulatory mechanisms operating with feedforward characteristics. The aim of the present study was to study nonbaroreflex sequences in a more physiological experimental model, i.e., in conscious freely moving rats. We studied conscious rats before and after 1) complete autonomic blockade (n 12), 2) sympathetic blockade (n 10), 3) (n 7)- and (n 8)-adrenergic blockade, and 4) parasympathetic blockade (n 10). Nonbaroreflex sequences were defined as three or more beats in which SAP and PI of the following beat changed in the opposite direction. Complete autonomic blockade reduced the number of nonbaroreflex sequences (95.6 9.0 vs. 45.2 4.1, P 0.001), as did sympathetic blockade (80.9 12.6 vs. 30.9 6.1, P 0.001). The selective -receptor blockade did not induce significant changes (80.9 12.5 in baseline vs. 79.0 14.7 after prazosin), whereas -receptor blockade significantly reduced nonbaroreflex sequence occurrence (80.9 12.5 in baseline vs. 48.9 15.3 after propranolol). Parasympathetic blockade produced a significant increase of nonbaroreflex sequences (95.1 6.9 vs. 136.0 12.4, P 0.01). These results demonstrate the physiological role of the nonbaroreflex sequences as an expression of a feedforward type of short-term cardiovascular regulation able to interact dynamically with the feedback mechanisms of baroreflex origin in the neural control of the sinus node

Carrageenan-induced acute inflammation in the mouse air pouch synovial model. Role of tumour necrosis factor

We used the mouse air pouch model of inflammation to study the interaction between cytokines, prostaglandin E2 (PGE2) and cell migration during the various phases of acute local inflammation induced by carrageenan. In serum, the levels of interleukin 1 (IL-1), interleukin 6 (IL-6), tumour necrosis factor (TNF), serum amiloid-A (SAA) and Fe++ were never different from controls, indicating that no systemic inflammatory changes were induced. Locally the exudate volume and the number of leukocytes recruited into the pouch increased progressively until 7 days after carrageenan. The same was true for PGE2 production. We could not measure IL-1 but the production of IL-6 and TNF reached a maximum after 5-24 h then quickly decreased. Anti-TNF antibodies inhibited cell migration by 50% 24 h after treatment. Pretreatment with interleukin 10 (IL-10) inhibited TNF production almost completely and cell migration by 60%. Carrageenan-induced inflammation was modulated by anti-inflammatory drugs. Pretreatment with dexamethasone (DEX) or indomethacin (INDO) inhibited cell migration and reduced the concentration of TNF in the exudate. Production of PGE2 or vascular permeability did not correlate with the number of cells in the pouch. Local TNF seems to play an important role in this model, particularly for leukocyte migration in the first phase of the inflammatory process. In conclusion, the air pouch seems to be a good model for studying the regulation of the early events of local inflammation, particularly the role of cytokines and cell migration

Diversity of dermal fibroblasts as major determinant of variability in cell reprogramming

Induced pluripotent stem cells (iPSCs) are adult somatic cells genetically reprogrammed to an embryonic stem cell-like state. Notwithstanding their autologous origin and their potential to differentiate towards cells of all three germ layers, iPSC reprogramming is still affected by low efficiency. As dermal fibroblast is the most used human cell for reprogramming, we hypothesize that the variability in reprogramming is, at least partially, because of the skin fibroblasts used. Human dermal fibroblasts harvested from five different anatomical sites (neck, breast, arm, abdomen and thigh) were cultured and their morphology, proliferation, apoptotic rate, ability to migrate, expression of mesenchymal or epithelial markers, differentiation potential and production of growth factors were evaluated in vitro. Additionally, gene expression analysis was performed by real-time PCR including genes typically expressed by mesenchymal cells. Finally, fibroblasts isolated from different anatomic sites were reprogrammed to iPSCs by integration-free method. Intriguingly, while the morphology of fibroblasts derived from different anatomic sites differed only slightly, other features, known to affect cell reprogramming, varied greatly and in accordance with anatomic site of origin. Accordingly, difference also emerged in fibroblasts readiness to respond to reprogramming and ability to form colonies. Therefore, as fibroblasts derived from different anatomic sites preserve positional memory, it is of great importance to accurately evaluate and select dermal fibroblast population prior to induce reprogramming

Requirements of the authorized examinator physician (AME) for class II: interpretative doubts and suggestions

The purpose of this document is to clarify the requirements that a doctor must have for carrying out the Authorized Examiner (AME) activity for class II workers. We have consulted the normative sources that indicate the requisite that the authorized physicians must possess and subsequently we have compared the norms, the European Union regulations and the national ones issued by the National Civil Aviation Body (ENAC), as well as the guidelines indicated by the EASA. Finally, Authors give suggestions that can be given to ENAC regarding the issue of the authorization as AME examiner for class II workers

Facile synthesis of cubic cuprous oxide for electrochemical reduction of carbon dioxide

Abstract: High level of atmospheric carbon dioxide (CO2) concentration is considered one of the main causes of global warming. Electrochemical conversion of CO2 into valuable chemicals and fuels has promising potential to be implemented into practical and sustainable devices. In order to efficiently realize this strategy, one of the biggest efforts has been focused on the design of catalysts which are inexpensive, active and selective and can be produced through green and up-scalable routes. In this work, copper-based materials are simply synthesized via microwave-assisted process and carefully characterized by physical/chemical/electrochemical techniques. Nanoparticle with a cupric oxide (CuO) surface as well as various cuprous oxide (Cu2O) cubes with different sizes is obtained and used for the CO2 reduction reaction. It is observed that the Cu2O-derived electrodes show enhanced activity and carbon monoxide (CO) selectivity compared to the CuO-derived one. Among various Cu2O catalysts, the one with the smallest cubes leads to the best CO selectivity of the electrode, attributed to a higher electrochemically active surface area. Under applied potentials, all Cu2O cubes undergo structural and morphological modification, even though the cubic shape is retained. The nanoclusters formed during the material evolution offer abundant and active reaction sites, leading to the high performance of the Cu2O-derived electrodes

The Long and Winding Road to Cardiac Regeneration

Cardiac regeneration is a critical endeavor in the treatment of heart diseases, aimed at repairing and enhancing the structure and function of damaged myocardium. This review offers a comprehensive overview of current advancements and strategies in cardiac regeneration, with a specific focus on regenerative medicine and tissue engineering-based approaches. Stem cell-based therapies, which involve the utilization of adult stem cells and pluripotent stem cells hold immense potential for replenishing lost cardiomyocytes and facilitating cardiac tissue repair and regeneration. Tissue engineering also plays a prominent role employing synthetic or natural biomaterials, engineering cardiac patches and grafts with suitable properties, and fabricating upscale bioreactors to create functional constructs for cardiac recovery. These constructs can be transplanted into the heart to provide mechanical support and facilitate tissue healing. Additionally, the production of organoids and chips that accurately replicate the structure and function of the whole organ is an area of extensive research. Despite significant progress, several challenges persist in the field of cardiac regeneration. These include enhancing cell survival and engraftment, achieving proper vascularization, and ensuring the long-term functionality of engineered constructs. Overcoming these obstacles and offering effective therapies to restore cardiac function could improve the quality of life for individuals with heart diseases

Ambulatory Blood Pressure Control and Subclinical Left Ventricular Dysfunction in Treated Hypertensive Subjects

Blood pressure (BP) control in hypertensive patients is crucial for reducing the risk of heart failure development and may be particularly important in elderly subjects, who have an especially high prevalence of hypertension and risk of heart failure (1). Left ventricular (LV) global longitudinal strain (GLS) is an echocardiographic measure of LV systolic function that can be an indicator of early subclinical cardiac dysfunction, even when LV ejection fraction is normal. The association of BP control with early subclinical LV dysfunction according to GLS has not been extensively studied, and it is also unknown whether assessing BP control with ambulatory blood pressure (ABP) monitoring is superior to using office BP measurements in this regard. Therefore, we investigated the association of BP control with GLS by using ABP and office BP criteria in a community-based, predominantly elderly cohort with normal LV ejection fraction

Effect of Video Observation and Motor Imagery on Simple Reaction Time in Cadet Pilots

Neuromotor training can improve motor performance in athletes and patients. However, few data are available about their effect on reaction time (RT). We investigated the influence of video observation/motor imagery (VO/MI) on simple RT to visual and auditory stimuli. The experimental group comprised 21 cadets who performed VO/MI training over 4 weeks. Nineteen cadets completed a sham intervention as control. The main outcome measure was RT to auditory and visual stimuli for the upper and lower limbs. The RT to auditory stimuli improved significantly post-intervention in both groups (control vs. experimental mean change for upper limbs: −40 ms vs. −40 ms, p = 0.0008; for lower limbs: −50 ms vs. −30 ms, p = 0.0174). A trend towards reduced RT to visual stimuli was observed (for upper limbs: −30 ms vs. −20 ms, p = 0.0876; for lower limbs: −30 ms vs. −20 ms, p = 0.0675). The interaction term was not significant. Only the specific VO/MI training produced a linear correlation between the improvement in the RT to auditory and visual stimuli for the upper (r = 0.703) and lower limbs (r = 0.473). In conclusion, VO/MI training does not improve RT when compared to control, but it may be useful in individuals who need to simultaneously develop a fast response to different types of stimuli

Higher Ambulatory Blood Pressure Is Associated With Aortic Valve Calcification in the Elderly: A Population-Based Study

Aortic valve calcification (AVC) without outflow obstruction (stenosis) is common in the elderly and increases the risk of cardiovascular morbidity and mortality. Although high blood pressure (BP) measured at the doctor’s office is known to be associated with AVC, little is known about the association between 24-hour ambulatory BP (ABP) and AVC. Our objective was to clarify the association between ABP variables and AVC. The study population consisted of 737 patients (mean age, 71±9 years) participating in the Cardiovascular Abnormalities and Brain Lesions study who underwent 24-hour ABP monitoring. Each aortic valve leaflet was graded on a scale of 0 (normal) to 3 (severe calcification). A total valve score (values 0–9) was calculated as the sum of all leaflet scores. Advanced AVC (score ≥4) was present in 77 subjects (10.4%). All of the systolic ABP variables (except systolic BP nocturnal decline) and mean asleep diastolic BP were positively associated with advanced calcification, whereas normal dipping status and diastolic BP nocturnal decline were negatively associated. Multiple regression analysis indicated that mean awake diastolic BP (odds ratio, 1.31 [95% CI, 1.01–1.71]) and asleep diastolic BP (odds ratio, 1.34 [95% CI, 1.04–1.72]) remained independently associated with advanced calcification after adjustment for age, sex, cigarette smoking, diabetes mellitus, hypercholesterolemia, hypertension, serum creatinine, and any degree of aortic insufficiency. Diastolic ABP is independently associated with advanced calcification. This finding may have important implications in gaining further insight into the mechanism of AVC

Alcohol Consumption and Ambulatory Blood Pressure: A Community-Based Study in an Elderly Cohort

BACKGROUND Although heavy alcohol consumption is associated with hypertension, the impact of lighter consumption on blood pressure (BP) is controversial. The protective effect of light alcohol consumption on cardiovascular disease described in previous studies could be, in part, mediated by effects of alcohol on BP. However, only a few studies investigating the association between alcohol and BP included elderly subjects, despite their higher risk of hypertension sequelae. Accordingly, we evaluated the relationship between alcohol consumption and 24-hour ambulatory BP in a community-based elderly cohort. METHODS Among the participants in the Cardiac Abnormalities and Brain Lesion study, 553 subjects (mean age = 70.6±9.6 years) who underwent 24-hour ambulatory BP monitoring were examined. Alcohol consumption was categorized as (i) none (reference; 1 drink/day). Former drinkers were excluded. RESULTS After adjustment for relevant covariables, mean values of daytime diastolic BP (DBP), nighttime DBP, and 24-hour DBP were significantly higher in moderate-to-heavy drinkers than in the reference group, whereas systolic BP parameters were not significantly different across consumption groups. Daytime systolic BP and DBP variability (SD of the measurements) were significantly lower in very light drinkers than in the reference group, independent of potential confounders. CONCLUSIONS Moderate-to-heavy alcohol consumption was associated with higher DBP values. Very light alcohol consumption was associated with reduced daytime BP variability. The latter association may contribute to the known beneficial cardiovascular effects of light alcohol consumption