Cardiac stereotactic body radiotherapy to treat malignant ventricular arrhythmias directly affects the cardiomyocyte electrophysiology.

BACKGROUND: Promising as a treatment option for life-threatening ventricular arrhythmias, cardiac stereotactic body radiotherapy (cSBRT) has demonstrated early antiarrhythmic effects within days of treatment. The mechanisms underlying the immediate and short-term antiarrhythmic effects are poorly understood. OBJECTIVES: We hypothesize that cSBRT has a direct antiarrhythmic effect on cellular electrophysiology through reprogramming of ion channel and gap junction protein expression. METHODS: Following exposure to 20Gy of X-rays in a single fraction, neonatal rat ventricular cardiomyocytes (NRVCs) were analyzed 24 and 96h post-radiation to determine changes in conduction velocity, beating frequency, calcium transients, and action potential duration (APD) in both monolayers and single cells. Additionally, the expression of gap junction proteins, ion channels, and calcium handling proteins was evaluated at protein and mRNA levels. RESULTS: Following irradiation with 20Gy, NRVCs exhibited increased beat rate and conduction velocities 24 and 96h after treatment. mRNA and protein levels of ion channels were altered, with the most significant changes observed at the 96h-mark. Upregulation of Cacna1c (Cav1.2), Kcnd3 (Kv4.3), Kcnh2 (Kv11.1), Kcnq1 (Kv7.1), Kcnk2 (K2P2.1), Kcnj2 (Kir2.1), and Gja1 (Cx43) was noted, along with improved gap junctional coupling. Calcium handling was affected, with increased Ryr2 (RYR2) and Slc8a1 (NCX) expression and altered properties 96h post-treatment. Fibroblast and myofibroblast levels remained unchanged. CONCLUSIONS: CSBRT modulates expression of various ion channels, calcium handling proteins, and gap-junction proteins. The described alterations in cellular electrophysiology may be the underlying cause of the immediate antiarrhythmic effects observed following cSBRT.

A comprehensive review of the epidemiology and clinical features of 91 cases with Buerger's disease.

BACKGROUND: Thromboangiitis Obliterans (TAO) is a disease of small and medium-sized arteries with an unclear natural course. This study aims to establish a national registry of the disease to gain a better understanding of its epidemiology and clinical course. METHOD: This study was a cohort study of 242 patients with a high probability of TAO admitted to Mashhad University of Medical Sciences (MUMS) hospitals from 2000 to 2015. Of these, 91 patients with a confirmed diagnosis were included in the study (90 males and 1 female) with a mean age of 35 ± 7.8 years. RESULTS: The most common symptom upon onset of the disease was paresthesia (29.7%), followed by cold sensitivity and paresthesia (93.4%) during the progression of the disease and Raynaud syndrome or vasospasm (93.9%) in the active phase. The right lower limb was the most commonly affected limb (46.2%), and presenting ischemic symptoms in 48.4%.Statistics indicated a positive correlation between the duration of Burger's disease and the number of affected limbs (p = 0.001). There was no effect of disease duration on the likelihood of amputations (p = 0.28). CONCLUSION: Some patients may experience mild, subtle symptoms for years before the initial signs and symptoms appear, which can be severe and rapidly progress to the point of requiring amputation.We suggest that the diagnostic criteria for Buerger's disease should be revised in light of the presence of atherosclerosis and its associated risk factors, which present a challenge in terms of diagnosis and treatment. Clinical experience will be of great importance in this regard.

BIN1, Myotubularin, and Dynamin-2 Coordinate T-Tubule Growth in Cardiomyocytes.

BACKGROUND: Transverse tubules (t-tubules) form gradually in the developing heart, critically enabling maturation of cardiomyocyte Ca2+ homeostasis. The membrane bending and scaffolding protein BIN1 (bridging integrator 1) has been implicated in this process. However, it is unclear which of the various reported BIN1 isoforms are involved, and whether BIN1 function is regulated by its putative binding partners MTM1 (myotubularin), a phosphoinositide 3'-phosphatase, and DNM2 (dynamin-2), a GTPase believed to mediate membrane fission. METHODS: We investigated the roles of BIN1, MTM1, and DNM2 in t-tubule formation in developing mouse cardiomyocytes, and in gene-modified HL-1 and human-induced pluripotent stem cell-derived cardiomyocytes. T-tubules and proteins of interest were imaged by confocal and Airyscan microscopy, and expression patterns were examined by RT-qPCR and Western blotting. Ca2+ release was recorded using Fluo-4. RESULTS: We observed that in the postnatal mouse heart, BIN1 localizes along Z-lines from early developmental stages, consistent with roles in initial budding and scaffolding of t-tubules. T-tubule proliferation and organization were linked to a progressive and parallel increase in 4 detected BIN1 isoforms. All isoforms were observed to induce tubulation in cardiomyocytes but produced t-tubules with differing geometries. BIN1-induced tubulations contained the L-type Ca2+ channel, were colocalized with caveolin-3 and the ryanodine receptor, and effectively triggered Ca2+ release. BIN1 upregulation during development was paralleled by increasing expression of MTM1. Despite no direct binding between MTM1 and murine cardiac BIN1 isoforms, which lack exon 11, high MTM1 levels were necessary for BIN1-induced tubulation, indicating a central role of phosphoinositide homeostasis. In contrast, the developing heart exhibited declining levels of DNM2. Indeed, we observed that high levels of DNM2 are inhibitory for t-tubule formation, although this protein colocalizes with BIN1 along Z-lines, and binds all 4 isoforms. CONCLUSIONS: These findings indicate that BIN1, MTM1, and DNM2 have balanced and collaborative roles in controlling t-tubule growth in cardiomyocytes.

Membrane remodelling triggers maturation of excitation-contraction coupling in 3D-shaped human-induced pluripotent stem cell-derived cardiomyocytes.

The prospective use of human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CM) for cardiac regenerative medicine strongly depends on the electro-mechanical properties of these cells, especially regarding the Ca2+-dependent excitation-contraction (EC) coupling mechanism. Currently, the immature structural and functional features of hiPSC-CM limit the progression towards clinical applications. Here, we show that a specific microarchitecture is essential for functional maturation of hiPSC-CM. Structural remodelling towards a cuboid cell shape and induction of BIN1, a facilitator of membrane invaginations, lead to transverse (t)-tubule-like structures. This transformation brings two Ca2+ channels critical for EC coupling in close proximity, the L-type Ca2+ channel at the sarcolemma and the ryanodine receptor at the sarcoplasmic reticulum. Consequently, the Ca2+-dependent functional interaction of these channels becomes more efficient, leading to improved spatio-temporal synchronisation of Ca2+ transients and higher EC coupling gain. Thus, functional maturation of hiPSC-cardiomyocytes by optimised cell microarchitecture needs to be considered for future cardiac regenerative approaches.

Functional microvascularization of human myocardium in vitro.

In this study, we report static and perfused models of human myocardial-microvascular interaction. In static culture, we observe distinct regulation of electrophysiology of human induced pluripotent stem cell derived-cardiomyocytes (hiPSC-CMs) in co-culture with human cardiac microvascular endothelial cells (hCMVECs) and human left ventricular fibroblasts (hLVFBs), including modification of beating rate, action potential, calcium handling, and pro-arrhythmic substrate. Within a heart-on-a-chip model, we subject this three-dimensional (3D) co-culture to microfluidic perfusion and vasculogenic growth factors to induce spontaneous assembly of perfusable myocardial microvasculature. Live imaging of red blood cells within myocardial microvasculature reveals pulsatile flow generated by beating hiPSC-CMs. This study therefore demonstrates a functionally vascularized in vitro model of human myocardium with widespread potential applications in basic and translational research.

In vitro evaluation of Kedo-S and RaCe rotary files compared to hand files in preparing the root canals of primary molar teeth.

BACKGROUND AND AIMS: Considering the advantages of rotary files in instrumenting the root canals of permanent teeth and a lack of adequate data on the use of these systems in primary teeth, the present study aimed to evaluate two rotary files and compare them with hand files in the cleaning efficacy of the root canals of primary molar teeth. MATERIALS AND METHODS: In the present study, three groups of teeth were prepared with Kedo-S paediatric rotary file system, RaCe (reamer with alternating cutting edges), and hand files (n = 40). The groups were evaluated under a stereomicroscope concerning the cleaning efficacy of the files after cleaning the teeth in the apical, middle, and coronal thirds. The data were analyzed with SPSS 24 (IBM Corporation, USA, 2016) using Fisher's exact test and chi-squared test; statistical significance was set at p < 0.05. RESULTS: There were no significant differences in the apical and middle thirds between the different study groups. However, there were significant differences in the coronal third between the hand file and Kedo-S (p = 0.016) and RaCe and Kedo-S (p = 0.001) groups. CONCLUSIONS: The present study showed that Kedo-S files were more effective than RaCe and hand files in the coronal area than the hand and RaCe files.

The Impact of COVID-19 on Female Sexual Function: A Systematic Review and Meta-Analysis.

Coronavirus disease 2019 (COVID-19) not only has put populations at risk for mental and sexual health risks. This systematic review and meta-analysis was performed on published articles reporting female sexual function before and during COVID-19 pandemic in PubMed, Web of Science, Scopus, Google Scholar, Magiran and SID databases till August 2021. From the initial 3198 articles, 8 articles were included in the review. Meta-analysis showed no significant difference in total FSFI score and its domains during the COVID-19 pandemic and the pre-pandemic period. Further studies should separately evaluate the effect of lockdown on female sexual function.

Physiological and pharmacological stimulation for in vitro maturation of substrate metabolism in human induced pluripotent stem cell-derived cardiomyocytes.

Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) enable human cardiac cells to be studied in vitro, although they use glucose as their primary metabolic substrate and do not recapitulate the properties of adult cardiomyocytes. Here, we have explored the interplay between maturation by stimulation of fatty acid oxidation and by culture in 3D. We have investigated substrate metabolism in hiPSC-CMs grown as a monolayer and in 3D, in porous collagen-derived scaffolds and in engineered heart tissue (EHT), by measuring rates of glycolysis and glucose and fatty acid oxidation (FAO), and changes in gene expression and mitochondrial oxygen consumption. FAO was stimulated by activation of peroxisome proliferator-activated receptor alpha (PPARα), using oleate and the agonist WY-14643, which induced an increase in FAO in monolayer hiPSC-CMs. hiPSC-CMs grown in 3D on collagen-derived scaffolds showed reduced glycolysis and increased FAO compared with monolayer cells. Activation of PPARα further increased FAO in cells on collagen/elastin scaffolds but not collagen or collagen/chondroitin-4-sulphate scaffolds. In EHT, FAO was significantly higher than in monolayer cells or those on static scaffolds and could be further increased by culture with oleate and WY-14643. In conclusion, a more mature metabolic phenotype can be induced by culture in 3D and FAO can be incremented by pharmacological stimulation.

Awakening the Secondary Metabolite Pathways of Promicromonospora kermanensis Using Physicochemical and Biological Elicitors.

The drug discovery rate is dramatically decreasing due to the rediscovery of known compounds. Genome mining approaches have revealed that a large portion of the actinobacterial genome that encodes bioactive metabolites is cryptic and not expressed under standard lab conditions. In the present study, we aimed to induce antibiotic encoding biosynthetic genes in a member of Micrococcales as a new species of Promicromonospora, Promicromonospora kermanensis, by chemical and biological elicitors as it was considered to produce numerous valuable bioactive metabolites based on the whole genome results. Induction has been done via chemical (antibiotics, histone deacetylase inhibitors (HDAIs), rare earth elements (REEs), fatty acid synthesis inhibitors, and extreme pH changes) and biological elicitors (live and dead Gram-positive and negative bacteria). The results showed that valproic acid (as HDAIs), DMSO, lanthanum chloride (as REE), triclosan (as fatty acid synthesis inhibitors), alkaline pH, and supernatant of Pseudomonas aeruginosa UTMC 1404 culture could act as stimuli to provoke antibacterial synthetic pathways in Promicromonospora kermanensis DSM 45485. Moreover, it was revealed that eliciting agents in cell filtrated of P. aeruginosa culture is resistant to detergent, acidic, and basic condition and have amphipathic nature. The inducing effect of alkaline pH on metabolite induction of Actinobacteria was first reported in this study. In the follow-up studies, the induced antibacterial producing clusters can be subjected to the characterization, and the implemented approach in this study can be used for metabolites induction in other selected species.

Humoral and cellular immune response to Buerger's disease.

OBJECTIVE: Thromboangiitis obliterans is a nonatherosclerotic occlusive disease, affecting small to moderate sized arteries of the upper and lower extremities, leading to progressive inflammation and clot formation. However, the role of humoral and cell-mediated immunity in the development of this disease has not been clearly identified. The present study was intended to investigate the humoral and cellular immune response in patients with Buerger's disease with different disease severity. METHODS: In an observational study, 80 male patients with Buerger's disease were included and categorized into three groups (mild, moderate, and severe) based on clinical manifestations. After blood sampling, cellular phenotypes were determined, and erythrocyte sedimentation rate, immunoglobulins (Ig) A, M, G, and E, as well as C3 and C4 components of the complement system and complement hemolytic activity (CH50) were measured. RESULTS: The mean age of the patient was 42.85 ± 8.39 years. Pulse abnormality, cold intolerance, and claudication were the most common symptoms. Eleven (13.75%), 46 (57.50%), and 23 (28.75%) patients had mild, moderate, and severe symptoms. Regression analyses showed that the presence of severe symptoms was significantly associated with elevated erythrocyte sedimentation rate and C4 levels (p < 0.05). CONCLUSION: Buerger's disease in severe cases was associated with increased erythrocyte sedimentation rate and abnormal C4 levels. The alterations in these inflammatory biomarkers might be due to a secondary inflammatory response to the presence of ulcer or gangrene and the inflammatory process in patients with severe symptoms.

The Cognitive Profile of People with High-Functioning Autism Spectrum Disorders.

Several studies have examined the cognitive profile of people with high-functioning autism spectrum disorders (ASD) (IQ > 70), and its relationship with the symptoms of ASD and attention deficit hyperactivity disorder (ADHD), using the Wechsler Intelligence Scale for Children-IV (WISC-IV). However, no data exist on the similarities or differences in this profile in less affluent countries. The present study examined the cognitive profile and its relationship with the symptoms of ASD and ADHD in 30 subjects aged 6⁻16 years with high-functioning ASD and compared the results with those of 30 typically developing (TD) subjects. In line with previous research findings, the WISC-IV cognitive profile analysis of subjects with high-functioning ASD showed a good competence in Matrix Reasoning and weaknesses in Comprehension, but the main distinguishing point was the competence in processing speed in both groups. In the present study, the Verbal Comprehension Index correlated negatively with the communication symptoms, and the Working Memory Index correlated positively with the social symptoms in the ASD group. Given the similarities that exist between the results of the present research and previous studies, it may be concluded that there are similarities in the cognitive profile of individuals with ASD.

Modulation of temporal resolution and speech long-latency auditory-evoked potentials by transcranial direct current stimulation in children and adolescents with dyslexia.

In recent years, transcranial direct current stimulation (tDCS) has been used as a safe and non-invasive method for children and adolescents with dyslexia. Our aim in this study was to investigate the effect of tDCS on variables of temporal resolution and speech long-latency auditory-evoked potentials with two electrode arrays on superior temporal gyrus (STG). A total of 17 children and adolescents with dyslexia (age 9-12 years) were included in our study. All participants underwent the gap in noise (GIN) test and long-latency auditory-evoked potentials recording at baseline without applying tDCS, sham (placebo), and after 20 min of exposure to two different tDCS polarities: anode of tDCS on left STG/cathode on the right shoulder and anode on the left STG/cathode on right STG to enhance left lateralization. Our results showed significant decreases in the threshold value and increases in the percentages of correct responses in the GIN test. We also found reduced latency and increased amplitude of the P1, N1, and P2 waves in two stimulation polarities compared with baseline and sham. Our findings indicate the potential role of tDCS on improving the characteristics of central auditory processing, especially temporal information processing in children and adolescents with dyslexia, and could introduce a new strategy to facilitate the rehabilitation of central auditory processing disorders in future.

Working Memory Training in the Form of Structured Games in Children with Attention Deficit Hyperactivity Disorder.

Objective: In this study, a new training method of working memory (WM) was used in the form of structured games, and the effect of training was evaluated with a controlled design. The training method of WM in the form of structured games includes 20 sets of structured games that can improve WM and performance of executive functions. Method: Sixty children with attention deficit hyperactivity disorder (ADHD) aged 8.5 to 11.2 years (35 boys), using no stimulant medication were selected. We randomly assigned 30 participants to the experimental group and provided them with WM training. The training was in the form of structured games and was offered to the participants in two 60-minute sessions weekly for 12 weeks. Other participants were assigned to the control group, receiving no treatment. All the participants were also evaluated at follow-up 6 months later. The main measures were the Child Behavior Checklist (CBCL), the Digit Span and Symbol Search B subscale of the Wechsler Intelligence Scale for Children (WISC-IV); and scores of dictation and mathematics were used in terms of pre and post-test. Results: The results of the t-test revealed a significant improvement in the post-test measures as well as a significant reduction of parents' reports of inattentiveness, and improvement in academic performance in the experimental group. However, no significant changes were found in the control group. Conclusion: The academic and working memory improvements were primarily due to the training method of WM. Our findings suggest that the training method of WM in the form of structured games may be a practical method for treating children with ADHD, but it needs to be further investigated.

Knowledge, attitudes, and practices of health care personnel concerning hand hygiene in Shiraz University of Medical Sciences hospitals, 2013-2014.

This study evaluated knowledge and self-reported attitudes and practices concerning hand hygiene among hospital workers in Shiraz, Iran, using a 68-question survey divided into 4 sections: demographics, knowledge, attitudes, and practices. Work experience had a correlation with practices and knowledge (P < .05), and knowledge and practices scores were positively correlated (P < .05). Participants appear to have sufficient knowledge and proper attitudes regarding hand hygiene; however, compliance practices were suboptimal.

Crocin Bleaching Assay Using Purified Di-gentiobiosyl Crocin (-crocin) from Iranian Saffron.

OBJECTIVES: Crocin bleaching assay (CBA) is a new method for determination of antioxidant capacity. In CBA, addition of hydrogen to the conjugated double bonds of crocin results in reduction of crocin and increase in the absorbance at 440 nm, which is considered as a measure of antioxidant potential. Here CBA method was set up using di-gentiobiosyl crocin or α-crocin from Iranian saffron. Then, the antioxidant activity of some known antioxidants i.e. L-ascorbic acid, bilirubin, Trolox, uric acid, and some plasma samples of infants, were tested. The results were compared to that obtained by ferric reducing antioxidant power" (FRAP) as a standard method. MATERIALS AND METHODS: Di-gentiobiosyl crocin was extracted and purified from Iranian saffron as previously described by us. Then, the CBA procedure using α-crocin was done in 2 different aquatic conditions, >50% or >90% of water. Results were analyzed by both the Bors method (calculating the relative rate constants= Krel) and the Tsimidou method (calculating the percent of -crocin bleaching inhibition=% Inh). RESULTS: OUR RESULTS INDICATED THE FOLLOWING ORDER OF ANTIOXIDANT POTENTIAL FOR THE ABOVE MENTIONED AGENTS: ascorbic acid > uric acid > Trolox. However, these results are very similar to the data reported by others, but they are strongly related to the aqueous condition. In addition, uric acid showed different properties at different concentrations; so that it showed the antioxidant activity at low concentrations but it acted as a prooxidant at higher concentrations. Bilirubin interfered with this test, possibly because its maximum absorbance is close to the crocin. The obtained data for the antioxidant capacity of the serums was comparable with FRAP assay, except for the sample that contains high bilirubin concentration. CONCLUSION: In conclusion, it seems that CBA using the main fraction of crocin (-crocin) is a simple and useful method for determination of antioxidant potential of aqueous samples. In addition, the CBA ability to distinguish the samples that contain bilirubin or high uric acid content is helpful in clinical laboratories.