Cardiovascular responses and the role of the neurohumoral cardiac regulation during digestion in the herbivorous lizard Iguana iguana.

Carnivorous reptiles exhibit an intense metabolic increment during digestion, which is accompanied by several cardiovascular adjustments responsible for meeting the physiological demands of the gastrointestinal system. Postprandial tachycardia, a well-documented phenomenon in these animals, is mediated by the withdrawal of vagal tone associated with the chronotropic effects of non-adrenergic and non-cholinergic (NANC) factors. However, herbivorous reptiles exhibit a modest metabolic increment during digestion and there is no information about postprandial cardiovascular adjustments. Considering the significant impact of feeding characteristics on physiological responses, we investigated cardiovascular and metabolic responses, as well as the neurohumoral mechanisms of cardiac control, in the herbivorous lizard Iguana iguana during digestion. We measured oxygen consumption rate (O2), heart rate (fH), mean arterial blood pressure (MAP), myocardial activity, cardiac autonomic tone, fH/MAP variability and baroreflex efficiency in both fasting and digesting animals before and after parasympathetic blockade with atropine followed by double autonomic blockade with atropine and propranolol. Our results revealed that the peak of O2 in iguanas was reached 24 h after feeding, accompanied by an increase in myocardial activity and a subtle tachycardia mediated exclusively by a reduction in cardiac parasympathetic activity. This represents the first reported case of postprandial tachycardia in digesting reptiles without the involvement of NANC factors. Furthermore, this withdrawal of vagal stimulation during digestion may reduce the regulatory range for short-term fH adjustments, subsequently intensifying the blood pressure variability as a consequence of limiting baroreflex efficiency.

Effects of exposure to sediment-associated fipronil on cardiac function of Neotropical armored catfish Hypostomus regani.

Fipronil is widely used as a broad-spectrum insecticide in agriculture, urban environments, and veterinary medicine. Fipronil can enter aquatic ecosystems and spread to sediment and organic matter, representing a risk to non-target species. This study aimed to evaluate the effects of short-term (96 h) exposure to a low and realistic concentration of sediment-associated fipronil (4.2 µg.kg-1 of Regent® 800 WG) on myocardial contractility of armored catfish Hypostomus regain, a benthic fish species. Fipronil exposure induced increased inotropism and acceleration of contractile kinetics, although no alterations in the relative ventricular mass were observed. This better cardiac function was associated with an elevated expression and/or function of the Na+/Ca2+ exchanger and its marked contribution to contraction and relaxation, probably due to a stress-induced adrenergic stimulation. Ventricle strips of exposed fish also exhibited a faster relaxation and a higher cardiac pumping capacity, indicating that armored catfish were able to perform cardiac adjustments to face the exposure. However, a high energetic cost to maintain an increased cardiac performance can make fish more susceptible to other stressors, impairing developmental processes and/or survival. These findings highlight the need for regulations of emerging contaminants, such as fipronil, to ensure adequate protection of the aquatic system.

Tolerance of an acute warming challenge declines with body mass in Nile tilapia: evidence of a link to capacity for oxygen uptake.

It has been proposed that larger individuals within fish species may be more sensitive to global warming, as a result of limitations in their capacity to provide oxygen for aerobic metabolic activities. This could affect size distributions of populations in a warmer world but evidence is lacking. In Nile tilapia Oreochromis niloticus (n=18, mass range 21-313 g), capacity to provide oxygen for aerobic activities (aerobic scope) was independent of mass at an acclimation temperature of 26°C. Tolerance of acute warming, however, declined significantly with mass when evaluated as the critical temperature for fatigue from aerobic swimming (CTSmax). The CTSmax protocol challenges a fish to meet the oxygen demands of constant aerobic exercise while their demands for basal metabolism are accelerated by incremental warming, culminating in fatigue. CTSmax elicited pronounced increases in oxygen uptake in the tilapia but the maximum rates achieved prior to fatigue declined very significantly with mass. Mass-related variation in CTSmax and maximum oxygen uptake rates were positively correlated, which may indicate a causal relationship. When fish populations are faced with acute thermal stress, larger individuals may become constrained in their ability to perform aerobic activities at lower temperatures than smaller conspecifics. This could affect survival and fitness of larger fish in a future world with more frequent and extreme heatwaves, with consequences for population productivity.

Usability and acceptability of internet-based interventions for family carers of people living with dementia: systematic review.

Objectives: Internet-based interventions can help carers of people living with dementia to cope with care-related challenges and can help improve their wellbeing. This systematic review aimed at investigating the criteria of usability and acceptability of self-guided internet-based interventions for family carers of people living with dementia. Method: Searches were conducted on PubMed, Virtual Health Library Regional Portal (Americas), MEDLINE, PsycINFO, Scopus, and Cochrane. Studies published up to December 2019, in English, Portuguese, or Spanish, were eligible. We followed the definition/criteria from ISO ISO-9241-11 for usability (efficiency, effectiveness, and satisfaction) and acceptability (barriers for using and utility). Methodological quality was evaluated using specific tools according to each study design. Results: Ten studies were included, all of which had high methodological quality. Carers of people living with dementia indicated that internet-based interventions were mostly effective, efficient, and satisfactory. They considered these to be informative, relevant, and functional, highlighting the utility and intention of using the resource in the future. The high heterogeneity in the terms and methods used to evaluate usability and acceptability hindered cross-study comparisons, however internet-based interventions were considered useful and acceptable by most carers. Conclusion: Future research should consider expanding the criteria of usability and acceptability to better reflect the needs of this population.

Cardiac contractility of the African sharptooth catfish, Clarias gariepinus: role of extracellular Ca2+, sarcoplasmic reticulum, and ß-adrenergic stimulation.

This study investigated the dependence of contraction from extracellular Ca2+, the presence of a functional sarcoplasmic reticulum (SR), and the effects of ß-adrenergic stimulation using isometric cardiac muscle preparations. Moreover, the expression of Ca2+-handling proteins such as SR-Ca2+-ATPase (SERCA), phospholamban (PLN), and Na+/Ca2+ exchanger (NCX) were also evaluated in the ventricular tissue of adult African sharptooth catfish, Clarias gariepinus, a facultative air-breathing fish. In summary, we observed that (1) contractility was strongly regulated by extracellular Ca2+; (2) inhibition of SR Ca2+-release by application of ryanodine reduced steady-state force production; (3) ventricular myocardium exhibited clear post-rest decay, even in the presence of ryanodine, indicating a decrease in SR Ca2+ content and NCX as the main pathway for Ca2+ extrusion; (4) a positive force-frequency relationship was observed above 60 bpm (1.0 Hz); (5) ventricular tissue was responsive to ß-adrenergic stimulation, which caused significant increases in twitch force, kept a linear force-frequency relationship from 12 to 96 bpm (0.2 to Hz), and improved the cardiac pumping capacity (CPC); and (6) African catfish myocardium exhibited similar expression patterns of NCX, SERCA, and PLN, corroborating our findings that both mechanisms for Ca2+ transport across the SR and sarcolemma contribute to Ca2+ activator. In conclusion, this fish species displays great physiological plasticity of E-C coupling, able to improve the ability to maintain cardiac performance under physiological conditions to ecological and/or adverse environmental conditions, such as hypoxic air-breathing activity.

Interactive effects of mercury exposure and hypoxia on ECG patterns in two Neotropical freshwater fish species: Matrinxã, Brycon amazonicus and traíra, Hoplias malabaricus.

Hypoxia and mercury contamination often co-occur in tropical freshwater ecosystems, but the interactive effects of these two stressors on fish populations are poorly known. The effects of mercury (Hg) on recorded changes in the detailed form of the electrocardiogram (ECG) during exposure to progressive hypoxia were investigated in two Neotropical freshwater fish species, matrinxã, Brycon amazonicus and traíra, Hoplias malabaricus. Matrinxã were exposed to a sublethal concentration of 0.1 mg L-1 of HgCl2 in water for 96 h. Traíra were exposed to dietary doses of Hg by being fed over a period of 30 days with juvenile matrinxãs previously exposed to HgCl2, resulting in a dose of 0.45 mg of total Hg per fish, each 96 h. Both species showed a bradycardia in progressive hypoxia. Hg exposure impaired cardiac electrical excitability, leading to first-degree atrioventricular block, plus profound extension of the ventricular action potential (AP) plateau. Moreover, there was the development of cardiac arrhythmias and anomalies such as occasional absence of QRS complexes, extra systoles, negative Q-, R- and S-waves (QRS complex), and T wave inversion, especially in hypoxia below O2 partial pressures (PO2) of 5.3 kPa. Sub-chronic dietary Hg exposure induced intense bradycardia in normoxia in traira, plus lengthening of ventricular AP duration coupled with prolonged QRS intervals. This indicates slower ventricular AP conduction during ventricular depolarization. Overall, the data indicate that both acute waterborne and sub-chronic dietary exposure (trophic level transfer), at sublethal concentrations of mercury, cause damage in electrical stability and rhythm of the heartbeat, leading to myocardial dysfunction, which is further intensified during hypoxia. These changes could lead to impaired cardiac output, with consequences for swimming ability, foraging capacity, and hence growth and/or reproductive performance.

Functional facial reconstruction in a patient with severe burn sequelae with a prelaminated parascapular free flap based on a three-dimensional model: A case report.

Significant evolution has been made concerning resuscitation and emergency management of severely burned patients, and nowadays most patients will survive and deal with burns sequelae. They constitute a reconstructive challenge, mainly because options and donor areas are frequently compromised, results are often limited, and other options should then be considered. A 27-year-old male patient with 55% total burn surface area, presented with severe facial disfigurement including ectropion, upper/lower lip retraction, and partial loss of the nose. In order to improve the patient's condition, autologous reconstruction was considered. The only unburned area in the body was the left dorsal region, and a three-stage reconstruction was planned using a paraescapular flap. In a first stage, an elective surgery was performed to identify and tag the recipient vessels in the neck. After 3 months, the prelamination process was initiated with the drawing of a facial model, and a nose and lips were opened inside the flap. This was based on a three-dimensional latex model as a print of the patient's face, which allowed us to calculate distances and estimate the length of the vascular pedicles. After 3 months, the flap (18 × 8 cm) was transferred and microvascular anastomoses were performed. No major complications were seen after surgeries, and after 28 months, an extremely important functional gain was obtained. Despite the number of surgeries required and less than optimal aesthetic results, this method may offer a satisfactory solution for complex acquired facial burn sequelae when other local or distant flap options are not available.

A microfluidic flow-focusing device for low sample consumption serial synchrotron crystallography experiments in liquid flow.

Serial synchrotron crystallography allows low X-ray dose, room-temperature crystal structures of proteins to be determined from a population of microcrystals. Protein production and crystallization is a non-trivial procedure and it is essential to have X-ray-compatible sample environments that keep sample consumption low and the crystals in their native environment. This article presents a fast and optimized manufacturing route to metal-polyimide microfluidic flow-focusing devices which allow for the collection of X-ray diffraction data in flow. The flow-focusing conditions allow for sample consumption to be significantly decreased, while also opening up the possibility of more complex experiments such as rapid mixing for time-resolved serial crystallography. This high-repetition-rate experiment allows for full datasets to be obtained quickly (∼1 h) from crystal slurries in liquid flow. The X-ray compatible microfluidic chips are easily manufacturable, reliable and durable and require sample-flow rates on the order of only 30 µl h-1.

Microcystin - LR exposure causes cardiorespiratory impairments and tissue oxidative damage in trahira, Hoplias malabaricus.

This study investigated the effect of microcystin-LR (MC-LR) on in vivo cardiorespiratory function and on tissue biomarkers of oxidative stress in gills and liver of the trahira, a neotropical freshwater fish. Trahira were treated with an intraperitoneal injection of 100 µg MC-LR.kg-1 body mass or a saline, with the toxic effects of MC-LR then evaluated after 48 h. Rates of oxygen uptake (V̇O2) did not differ significantly between Control and the exposed group (Mcys), but exposure to MC-LR significantly reduced O2 extraction in the Mcys group at all O2 tensions. This was associated with higher gill ventilation volume (V̇G) in the Mcys group at all O2 tensions except 140 and 120 mmHg, and a higher tidal volume (VT) of the Mcys group at all tensions except 140 mmHg. Heart rate was also higher in the Mcys group, significantly so at an O2 tension of 40 mmHg. In the liver of trahira, exposure to MC-LR has significant effects on antioxidant defense systems, inducing a significant increase in the activity of the (GPx) glutathione peroxidase enzyme (100%) and in the reduced glutathione (GSH) content (70%) compared to the control group, but no effects on superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST) enzymes. The liver showed no oxidative damage, when measured as lipid peroxidation (LPO) levels and protein carbonyl (PC) content. In the gills SOD and GPx enzyme activity increased significantly in the Mcys group (98% and 73% respectively) compared to the controls, although GSH, CAT and GST did not differ between groups. There was also no significant difference in GSH in this tissue. Levels of lipid peroxidation in the gills were 53% higher in the Mcys group, although carbonyl protein levels did not differ. In conclusion, these data show that MC-LR leads to development of hyperventilation and increased activity of the detoxification system and that this species was able to compensate the deleterious effects of microcystin on its vital functions. The antioxidant defense in the liver was able to contain the propagation of LPO and prevent the oxidation of proteins, although the gills of the fishes exposed to MC-LR were not able to contain the formation of reactive oxygen species and LPO, which led to the establishment of oxidative stress which impaired gill function.

Pharyngocutaneous and tracheoesophageal fistula closure using supraclavicular artery island flap.

BACKGROUND: Pharyngocutaneous fistula is a common complication of laryngopharyngeal surgery, being associated with increased morbidity and mortality. Classical regional and free flaps, frequently used in the treatment of this complication, have several limitations, including bulking, donor site morbidity and long operative time. The supraclavicular artery island flap (SCAIF) is a fasciocutaneous flap and presents as an alternative option with good results and without the previously stated limitations. We describe our experience with SCAIF in pharyngocutaneous and tracheoesophageal fistula closure. METHODS: Between April and December 2017, four patients with pharyngocutaneous and two patients with tracheoesophageal fistula underwent fistula closure with SCAIF. Clinical records were retrospectively reviewed. RESULTS: Pharyngocutaneous fistulae were associated with anterior esophageal wall defects ranging from 4 to 13.5 cm2. Tracheoesophageal fistulae defects were smaller (approximately 2 cm2). Fistula closure was achieved in all patients, oral diet was started on the 14th day post-operative and there were no signs of recurrence during follow-up. The donor area was complicated with the formation of hematoma in two patients. CONCLUSIONS: The SCAIF has unique features that makes it an ideal option for pharyngocutaneous and tracheoesophageal fistula closure, namely, reliable perfusion, quick and simple dissection, pliability and minor donor site morbidity. Local complications do not significantly affect long term morbidity of the donor area and can be avoided with simple measures.

The Mechanism of Regulation of Pantothenate Biosynthesis by the PanD-PanZ·AcCoA Complex Reveals an Additional Mode of Action for the Antimetabolite N-Pentyl Pantothenamide (N5-Pan).

The antimetabolite pentyl pantothenamide has broad spectrum antibiotic activity but exhibits enhanced activity against Escherichia coli. The PanDZ complex has been proposed to regulate the pantothenate biosynthetic pathway in E. coli by limiting the supply of ß-alanine in response to coenzyme A concentration. We show that formation of such a complex between activated aspartate decarboxylase (PanD) and PanZ leads to sequestration of the pyruvoyl cofactor as a ketone hydrate and demonstrate that both PanZ overexpression-linked ß-alanine auxotrophy and pentyl pantothenamide toxicity are due to formation of this complex. This both demonstrates that the PanDZ complex regulates pantothenate biosynthesis in a cellular context and validates the complex as a target for antibiotic development.

Nine years of a single referral center management of Stevens-Johnson syndrome and toxic epidermal necrolysis (Lyell's syndrome).

CONTEXT: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) corresponds to a rare and acute life-threatening mucocutaneous reactions characterized by extensive necrosis and epidermal detachment. There are no efficacious pharmaceutical interventions proven through large clinical trials. OBJECTIVE: We sought to study clinical cases admitted in our institution in order to determine which drugs and medical comorbidities or treatments impacted the mortality. MATERIAL AND METHODS: In a retrospective study over 9 years we evaluated all patients presenting biopsy-proven SJS or TEN for age, gender, total body surface area involved, causing agents, SCORTEN score, blood transfusion, steroid administration, intubation, length of intensive care stay and death rate. Statistical analysis was done using SPSS statistical software. RESULTS: The highest incidence of SJS and TEN was in age group of 71-80 years. Of the 30 patients, 30% died from SJS/TEN, mainly due sepsis. For each subgroup SJS/TEN overlap had the highest mortality. The highest mortality was from antibiotic treatment as causing agent. Step-wise regression analysis identified mechanical ventilation requirement and age over 65 years as mortality high-risk factors. DISCUSSION: The most crucial interventions are discontinuation of the offending drug and prompt referral to a burn unit, which helps in early diagnosis and decrease mortality in these diseases. CONCLUSION: When SJS/TEN is caused by antibiotics suspicion of developing fatal sepsis should be high, independently of patients' medical condition.

Fascicular Phrenic Nerve Neurotization for Restoring Physiological Motion in a Congenital Diaphragmatic Hernia Reconstruction With a Reverse Innervated Latissimus Dorsi Muscle Flap.

Congenital diaphragmatic hernia is a severe developmental anomaly characterized by the malformation of the diaphragm. An innervated reversed latissimus dorsi flap reconstruction for recurrent congenital diaphragmatic hernia has been described as an alternative to prosthetic patch repair to achieve pleuroperitoneal separation. However, there is very little supporting scientific data; therefore, there is no real basic understanding of the condition of the phrenic nerve in the absence of diaphragmatic muscle or even the neurotization options for restoring neodiaphragmatic muscle motion. We have reviewed the literature regarding phrenic nerve anatomy and neurotization options, and to our knowledge, this is the first time that the application of a fascicular repair is being described where the continuity of one remaining fascicle of the diaphragm has been preserved close to the phrenic nerve distal division. The procedure was undertaken in a 3 year-old boy, with the diagnosis of congenital large posteromedial diaphragmatic hernia and dependence of mechanical ventilation in consequence of severe bronchopulmonary dysplasia.The phrenic nerve divides itself into several terminal branches, usually three, at the diaphragm level, or just above it. This allows the selective coaptation of separate fascicular branches. In the case described, videofluoroscopy evaluation showed no evidence of paradoxical neodiaphragmatic motion, with synchronous contraction movements and intact pleura-peritoneal separation. The child is now asymptomatic and shows improvement of his previous restrictive pulmonary disease.We believe that fascicular repair can achieve some reinnervation of the flap without jeopardizing the potential of diaphragmatic function by contraction of reminiscent native diaphragm.

Facial allotransplantation procurement using a transparotid approach: a new anatomical model.

BACKGROUND: Full face transplantation is a complex procedure and a detailed plan is needed. Coaptation of motor nerve branches at more distal sites instead of the level of the main trunk is highly desirable, but may be difficult to find, are thin, fragile and have limited length for safe and tension-free coaptation. In addition, nerve grafts may be necessary. In this study, the technical feasibility of facial allotransplantation procurement using a transparotid approach was investigated. METHODS: Three mock cadaver dissections were performed, procuring full face transplants with en bloc facial nerve dissection. The facial nerve (main trunk, temporofacial/cervicofacial divisions, and individual facial branches) was elevated en bloc as part of the allograft, dissected out from the parotid completely, and left as loose attachments to the allograft specimen. RESULTS: Full face transplantation with en bloc facial nerve dissection was technically feasible, allowing for more proximal or distal nerve section, and to achieve the desired length and diameter for appropriate matching during nerve coaptation. CONCLUSION: This technique follows principles of targeted nerve reinnervation. It allows to select the level of facial nerve section to the temporofacial and cervicofacial divisions or final branches, with further adaptation to the remaining recipient's anatomic structures, and avoiding the need for nerve grafts; it also excludes the parotid gland (reduces bulk). Despite a small increase in the time required for dissection, this disadvantage may be compensated by an improved functional recovery.

Microsurgical reconstruction for radiation- and bisphosphonate-induced mandible osteonecrosis based on patient-specific physiopathologic mechanisms.

BACKGROUND: Radiation- and bisphosphonate-induced mandible osteonecrosis have distinct underlying physiopathologic mechanisms, but both can constitute a serious problem and lead to functional impairment and facial disfigurement. METHODS AND RESULTS: We describe different clinical situations related to several grades of osteonecrosis, where different options of free transfer should be considered based on case-specific physiopathologic mechanisms. We propose a simple clinical grading system to predict the best treatment option. CONCLUSIONS: For patients with advanced refractory disease, pathologic fracture, orocutaneous fistula, and severe osteolysis, resection associated with microvascular reconstruction seems to be a valid option that stops the underlying pathophysiology of overinfected avascular bone necrosis. Physicians who understand the specific physiopathologic mechanisms of each case can incorporate them into the assessment of the required reconstruction and treatment plans.

Chimeric flaps and "their variations": different options for immediate reconstruction of massive facial defects.

The reconstruction of massive head and neck defects is a difficult challenge, requiring restoration of bone, skin, and oral lining. Their complex three-dimensional nature often dictates the need of more than a single osteocutaneous flap for intra- and extra-oral reconstruction.Conventional reconstructive options can be considered, but there is no single ideal osteocutaneous free or pedicled flap providing an unlimited length of bone and skin paddle, or that could orient the skin paddle independently of the vascularized bone. The surgeon should then be aware of more complex options for reconstruction of extensive three-dimensional defects, namely chimeric free flaps and "their variations." They can be stratified in three types, either based on their intrinsic vasculature-perforated-based, branch-based, or whether they are prefabricated (surgical junction by microanastomosis).Despite morbidity and not perfect matching in terms of skin texture and pliability, these techniques are a good alternative in the presence of partial defects, especially in the context of immediate oncological reconstruction, where facial transplantation is not considered.

The Association of Levels of Mindfulness on the Cognitive Performance of Community-Dwelling, Low-Educated Older Adults From a Middle-Income Country.

Limited information exists on the potential link between levels of mindfulness and cognitive performance in seniors with low education. This cross-sectional study aims to explore the association between mindfulness levels and cognitive performance in older adults with different years of education. Participants were grouped by education levels and assessed for cognitive performance (ACE-R; Digit Span test), levels of mindfulness (Langer Mindfulness Scale-21), and depressive symptoms (Geriatric Depression Scale-15). Group comparisons, correlations, and linear and logistic regression analyses were conducted (p < .05). Cognitive performance, mindfulness levels, and depressive symptoms differed between groups, and correlations were found between mindfulness levels, ACE-R, and Digit Span scores. After controlling for education, the association between mindfulness levels and ACE-R performance remained significant. Logistic regression revealed that higher education and mindfulness levels increased the likelihood of scoring above the ACE-R cut-off. This study underscores the association between levels of mindfulness and cognitive performance in older adults.

Oxidative stress and neurotoxicity induced by exposure to settleable atmospheric particulate matter in bullfrog tadpoles, Aquarana catesbeiana, (Shaw, 1802).

Bullfrog tadpoles, Aquarana catesbeiana, were exposed to settleable particulate matter (SePM), (1 g L-1, 96 h) and their organs were collected for analysis of metal/metalloid, oxidative stress and neurotoxicity in liver, muscle, kidney and brain. The SePM water of the exposed groups contained 18 of the 28 metals/metalloids detected in ambient particulate matter (APM). Fe56 and Al were those that presented the highest concentrations, Cr, Mn, Pb and Cu increased from 10 to 20 times and Ti, V, Sr, Rb, Cd, Sn and Ni increased from 1 to 3 times compared to the control. Bioaccumulation of metals/metalloids in the exposure water varied significantly between organs, with the muscle and liver showing the highest concentrations of metals, followed by the brain. Lipoperoxidation and malondialdehyde increased only in muscle, while carbonyl proteins increased only in the liver and brain. Regarding nitric oxide synthase, there was an increase in the liver and brain in the group exposed to SePM. Catalase activity decreased in the liver and muscle, while the activity of glutathione peroxidase, increased in the liver and kidney and decreased in muscle. Glutathione S-transferase, which is mainly responsible for detoxification, increased in the liver and decreased in muscle and the kidney. Cholinesterase activity increased only in the muscle. The results indicate oxidative stress, due to oxidation catalyzed by metals, components of SePM. Thus, the results contribute to the understanding that SePM has a deleterious effect on the aquatic environment, negatively affecting bullfrog tadpoles, in different ways and levels in relation to the analyzed organs.

Activation of the cannabinoid type 2 (CB2) receptor improves cardiac contractile performance in fish, Brycon amazonicus.

In addition to their well-known classical effects, cannabinoid CB1 and CB2 receptors have also been involvement in both deleterious and protective actions on the heart under various pathological conditions. While the potential therapeutic applications of the endocannabinoid system in the context of cardiovascular function are indeed a viable prospect, significant debate exists within the literature regarding whether CB1, CB2, or a combination of both receptors exert a favorable influence on cardiac function. Hence, the aim of this study was to investigate the effects of CB1 + CB2 or CB2 agonists on cardiac excitation-contraction (E-C) coupling, utilizing fish (Brycon amazonicus) as an experimental model. The CB2 agonist elicited marked positive inotropic and lusitropic responses in isolated ventricular myocardium, induced cyclic adenosine 3',5'-monophosphate (cAMP) production, and upregulated critical Ca2+ handling proteins, such as sarco/endoplasmic reticulum Ca2+-ATPase (SERCA) and Na+/Ca2+ exchanger (NCX). Our current study demonstrated, for the first time, that CB2 receptor activation-induced effects improved the efficiency of Ca2+ cycling, excitation-contraction coupling (E-C coupling), and cardiac performance in under physiological conditions. Hence, CB2 receptors could be considered a potential therapeutic target for modulating cardiac contractile dysfunctions.

Translation and cultural adaptation of the Positive Aspects of Caregiving Scale for caregivers of people living with dementia in Brazilian context: a methodological study.

BACKGROUND: The Positive Aspects of Caregiving (PAC) scale is used to assess psychosocial benefits provided to caregivers by the task of caring. The PAC scale consists of nine items, assessed using a five-point Likert scale, with higher values indicating greater positive perceptions and gains from the caregiving experience. OBJECTIVE: To translate and culturally adapt the PAC scale for informal Brazilian caregivers of people with dementia. DESIGN AND SETTING: A methodological study was conducted at the Federal University of São Carlos. METHODS: The following stages were carried out: Translation; Synthesis of the translations; Back-translation; Evaluation by an experts' committee; and Pre-test. RESULTS: Two independent professionals translated the PAC scale. The consensus version was obtained by merging both translations, which were back-translated into English by a third translator. The expert committee comprised three specialists in the area and project researchers. All scale items presented a Content Validity Index of 1 (CVI = 1.0), and thus remained in the pre-final version of the instrument. The instrument was pre-tested with seven caregivers of people with dementia, the majority of whom were women (57.1%), with a degree of kinship corresponding to sons/daughters (57.1%) and an average age of 55.2 (± 4.1) years. The caregivers considered it clear and understandable and made no suggestions for changes. CONCLUSION: The PAC scale was translated and culturally adapted for use by informal caregivers of people with dementia in Brazil. However, a psychometric analysis of the instrument is necessary to provide normative data for this population group.