The angiotensin receptor blocker losartan reduces coronary arteriole remodeling in type 2 diabetic mice

Cardiovascular complications are a leading cause of morbidity and mortality in type 2 diabetes mellitus (T2DM) and are associated with alterations of blood vessel structure and function. Although endothelial dysfunction and aortic stiffness have been documented, little is known about the effects of T2DM on coronary microvascular structural remodeling. The renin–angiotensin–aldosterone system plays an important role in large artery stiffness and mesenteric vessel remodeling in hypertension and T2DM. The goal of this study was to determine whether the blockade of AT₁R signaling dictates vascular smooth muscle growth that partially underlies coronary arteriole remodeling in T2DM. Control and db/db mice were given AT₁R blocker losartan via drinking water for 4 weeks. Using pressure myography, we found that coronary arterioles from 16-week db/db mice undergo inward hypertrophic remodeling due to increased wall thickness and wall-to-lumen ratio with a decreased lumen diameter. This remodeling was accompanied by decreased elastic modulus (decreased stiffness). Losartan treatment decreased wall thickness, wall-to-lumen ratio, and coronary arteriole cell number in db/db mice. Losartan treatment did not affect incremental elastic modulus. However, losartan improved coronary flow reserve. Our data suggest that Ang II–AT₁R signaling mediates, at least in part, coronary arteriole inward hypertrophic remodeling in T2DM without affecting vascular mechanics, further suggesting that targeting the coronary microvasculature in T2DM may help reduce cardiac ischemic events.     

The Impact of Testosterone on the QT Interval: A Systematic Review

Humans and mammals have sex-specific differences in cardiac electrophysiology, linked to the action of sex hormones in the cardiac muscle. These hormones can upregulate or downregulate the expression of ionic channels modulating the cardiac cycle through genomic and non-genomic interactions. Systematic search in PubMed, Medline and EMBASE including keywords pertaining to testosterone and QT interval. Included experimental studies and observation studies and case reports presenting the results of testosterone administration, excess or deficiency in humans and animals. Testosterone has been shown to shorten the action potential duration, by enhancing the expression of K⁺ channels and downregulating I_CaL increasing the repolarization reserve of the cardiac muscle. This effect has been observed in both genders and animals. Testosterone deficient states can promote arrhythmogenesis. The evidence in this paper may be used to guide clinical considerations, such as increased clinical surveillance of patients in testosterone deficient states using ECG.     

Influenza vaccination and the endurance against air pollution among elderly with acute coronary syndrome

ObjectiveAir pollution, weather condition and influenza are known risk factors of acute coronary syndrome (ACS) among elderly people. The influenza vaccine (IV) has been shown to reduce major cardiovascular events. The purpose of this study was to compare resistance to air pollution and weather factors causing ACS between vaccinated and less-vaccinated elderly people.MethodsA case–crossover design was applied to 1835 elderly ACS patients who were obtained from the 1-million sample of Taiwan National Health Insurance Research Data with inclusion criteria: (1) the first diagnosis of ACS was in cold season and at age 68 or more, (2) had received the free IV program at least once during the period 3 years before the ACS. They were stratified into two groups: 707 had received flu vaccinations for all the 3 years and the remaining 1128 had not. The measurements of air pollutants, temperature, and humidity corresponding to each of the 3 days prior to the ACS diagnosis date were retrieved from the data banks of the Taiwan Environmental Protection Administration and Central Weather Bureau.FindingsIncreases in air pollution concentrations of CO, NO₂, PM₁₀ or PM_2.5 and decreases in temperature significantly influenced the risk of ACS for the non-continuously vaccinated elderly population; however, less significant effects were observed for the continuously vaccinated population.ConclusionConsecutive influenza vaccination may potentially offer resistance against the detrimental effects of air pollution and changes in temperature in frail elderly adults with ACS. Future studies are needed to directly assess the interaction effect between the vaccination and environmental factors on ACS.     

CRRT治疗老年顽固性心力衰竭的疗效观察

顽固性心力衰竭(CHF)是临床常见而又难治的心脏疾病,其病死率一直居高不下,虽然国内外许多学者采用了多种综合性措施,如主动脉内气囊反搏、植入心脏起搏器等,然而其预后仍较差。近几年来国外学者采用血滤或血透的方法矫治顽固性CHF取得了一些进展。由于研究结果差异较大,已成为     

壳聚糖醋酸溶液对凝血作用的研究

研究了不同脱乙酰度和不同分子量壳聚糖醋酸溶液的凝血作用。发现壳聚糖醋酸溶液使抗凝血液中红细胞发生了明显的聚集和变形。通过不同分子量和脱乙酰度壳聚糖的促红细胞聚集实验,证明了低脱乙酰度壳聚糖(60%~70%)使红细胞聚集效果更好,分子量在105~106范围内作用不十分明显。对血液的凝血酶时间(TT)、凝血酶原时间(PT)、活化部分促凝血酶原激酶时间(APTT)和纤维蛋白原浓度(FIB)的测定结果验证了壳聚糖醋酸溶液凝血机理不依赖于血小板和常规“瀑布”凝血机制。     

Characteristics of injuries among infants who fall from bed

IntroductionAccidental falls are the most common causes of injury among infants. Due to their limited ability to move independently, falling from bed or other types of furniture (such as sofas or armchairs) is considered the most common reason for such injury. However, little is known about the frequency and types of injury associated with this type of fall among infants. This study aimed to determine the incidence and characteristics of injury among infants presented at emergency departments (ED) after falling from bed or similar furniture.MethodsThe retrospective analysis of infants under one year old presenting at ED after falling from bed (or similar furniture) was performed over a four-year period (2016–2019). Patient demographics, incidence and patterns of injury, outcomes, and ED resources use were evaluated as part of the study.ResultsIn total, 1,439 infants were included in the study, of whom 782 (54.3%) were male and 657 (45.7%) female. The median age of the patients was 7 months (interquartile range [IQR]: 6–9 months). More than half the infants (n = 812, 56.4%) had minor injuries, such as abrasions, bruising, contusions, and lacerations. There were significant injuries for 135 (9.4%) infants. The most common fracture was skull fracture (n = 59, 4.1%), followed by proximal fracture of the upper extremities (n = 26, 1.8%). Six (0.4%) patients had radial head subluxation. Traumatic brain injury featured for 30 (2.1%) infants (intracranial hemorrhage/cerebral contusion). While the majority of patients (n = 1352, 94%) were discharged from ED, 86 (6%) infants were hospitalized, all due to head injuries. A neurosurgical intervention was performed with three (0.2% of all patients) of the hospitalized patients.ConclusionFalling from bed causes skull fractures, traumatic brain injury, and long bone fractures among infants. Therefore, campaigns should be organized to raise awareness of these risks among parents and caregivers of infants. In addition, the use of safety equipment (such as bed rails) and creating a safe environment can help prevent significant injuries.     

Efficacy of Antiosteoporotic Medications in Patients With Rebound-Associated Fractures After Denosumab Discontinuation

Denosumab discontinuation results in rapid bone loss and increased risk of multiple rebound-associated vertebral fractures (RAVFs). The optimal treatment for patients who have sustained such fractures is currently unknown. We aimed to investigate the bone mineral density (BMD) changes achieved with various regimens in postmenopausal women who had sustained RAVFs after denosumab discontinuation in everyday clinical practice. In this multicenter, retrospective observational study, 39 Greek postmenopausal women from six regional bone centers throughout Greece with RAVFs after denosumab discontinuation were included. We collected BMD and fracture data before and 1 year after treatment with denosumab (n = 20), teriparatide (n = 8), zoledronate (n = 8) or teriparatide/denosumab combination (n = 3). Both lumbar spine (LS)-- and femoral neck (FN)-BMD were preserved with all regimens used. With the exception of zoledronate, a trend towards increase was observed with all regimens in LS-BMD. Three patients sustained additional fractures despite treatment reinstitution (2 with zoledronate and 1 with teriparatide). Among patients with RAVFs following denosumab discontinuation both antiresorptive (zoledronate and denosumab) and anabolic (teriparatide) treatment as well as the combination of denosumab with teriparatide seem to be effective in terms of BMD response.