45 research outputs found

    Methylmercury Poisoning Induces Cardiac Electrical Remodeling and Increases Arrhythmia Susceptibility and Mortality

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    This study aims to investigate the cardiac electrical remodeling associated with intoxication by methylmercury (MeHg). We evaluated the chronic effects of MeHg on in vivo electrocardiograms and on ex vivo action potentials and depolarizing (ICa-L) and repolarizing (Ito) currents. The acute effect of MeHg was evaluated on HEK293 cells expressing human ERG, Kv4.3 and KCNQ1/KCNE1 channels. Chronic MeHg treatment increased QTc and Tpeak–Tend interval duration, prolonged action potential duration and decreased amplitude of Ito and ICa-L. In addition, heterologously expressed IhKv4.3, IhERG or IhKCNQ1/KCNE1 decreased after acute exposure to MeHg at subnanomolar range. The introduction of the in vitro effects of MeHg in a computer model of human ventricular action potentials triggered early afterdepolarizations and arrhythmia. In conclusion, cardiac electrical remodeling induced by MeHg poisoning is related to the reduction of Ito and ICa-L. The acute effect of MeHg on hKv4.3; hERG and hKCNQ1/KCNE1 currents and their transposition to in silico models show an association between MeHg intoxication and acquired Long QT Syndrome in humans. MeHg can exert its high toxicity either after chronic or acute exposure to concentrations as low as picomolar.This work was supported by grants from the Gobierno Vasco PIBA2018-58 and GIC18/150

    Perception of Filipino physicians on the roles and scope of practice of physical therapy in the Philippines: A multi-method quantitative study

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    Introduction: Physical therapists (PTs) are licensed practitioners who can assess, diagnose, and provide treatment interventions that restore patients to optimal function. While PTs can deliver complete management plans, the practice of physical therapy (PT) in the Philippines follows a referral system where physicians are the first contact of the patient, emphasizing the importance of physician\u27s perception towards the role of PTs and scope of PT service. This study aimed to determine the internal consistency of the Perception on Physical Therapists Questionnaire (PoPTQ), and to use this tool to report the existing perceptions of Filipino physicians on the practice of PT. Method: This study was divided into two phases and utilized a multi-method quantitative research design. For Phase 1 (psychometric), 18 questionnaires administered to Filipino physicians were used to compute Cronbach\u27s α of PoPTQ. A total of 134 questionnaires of the same population were analyzed for Phase 2 (cross-sectional), in which descriptive statistics and cross tab analysis were used to report the respondents\u27 perceptions. Both phases utilized online means of data gathering done via convenience sampling. Results: Phase 1 revealed a Cronbach\u27s α value of 0.528 for all items of PoPTQ. Phase 2 showed that physicians who have attended lectures discussing the roles of PTs or have experience with working with them have a higher referral rate than those with no prior exposure to PTs. Discussion: Filipino physicians believe that PTs can establish strong patient-therapist relationships, treat different patients, and acknowledge the roles of PTs in clinical and research settings. Data suggest that adequate foundational knowledge, positive perceptions, and high awareness of PTs\u27 roles and scope of practice are observed among Filipino physicians. However, there remains a need to increase collaboration opportunities between PTs and physicians in their academic years and programs that focus on the promotion of PT roles and scope of practice

    Autoimmune enteropathy with a CD8+ CD7- T-cell small bowel intraepithelial lymphocytosis: case report and literature review

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    <p>Abstract</p> <p>Background</p> <p>Adult onset autoimmune enteropathy (AIE) is a rare condition characterized by diarrhea refractory to dietary therapy diagnosed in patients with evidence of autoimmune conditions. Auto-antibodies to gut epithelial cells and other tissues are commonly demonstrated. Despite increasing awareness, the pathogenesis, histologic, immunologic and clinical features of AIE remain uncertain. There remains controversy regarding the diagnostic criteria, the frequency and types of auto-antibodies and associated autoimmune conditions, and the extent and types of histologic and immunologic abnormalities. CD4+ T-cells are thought to at least responsible for this condition; whether other cell types, including B- and other T-cell subsets are involved, are uncertain. We present a unique case of AIE associated with a CD8+CD7- lymphocytosis and review the literature to characterize the histologic and immunologic abnormalities, and the autoantibodies and autoimmune conditions associated with AIE.</p> <p>Case Presentation</p> <p>We present a case of immune mediated enteropathy distinguished by the CD8+CD7- intra-epithelial and lamina propria lymphocytosis. Twenty-nine cases of AIE have been reported. The majority of patients had auto-antibodies (typically anti-enterocyte), preferential small bowel involvement, and predominately CD3+ CD4+ infiltrates. Common therapies included steroids or immuno-suppressive agents and clinical response with associated with histologic improvement.</p> <p>Conclusions</p> <p>AIE is most often characterized (1) IgG subclass anti-epithelial cell antibodies, (2) preferential small bowel involvement, and (3) CD3+ alphabeta TCR+ infiltrates; there is insufficient evidence to conclude CD4+ T-cells are solely responsible in all cases of AIE.</p

    Expression of Human Frataxin Is Regulated by Transcription Factors SRF and TFAP2

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    Friedreich ataxia is an autosomal recessive neurodegenerative disease caused by reduced expression levels of the frataxin gene (FXN) due to expansion of triplet nucleotide GAA repeats in the first intron of FXN. Augmentation of frataxin expression levels in affected Friedreich ataxia patient tissues might substantially slow disease progression.We utilized bioinformatic tools in conjunction with chromatin immunoprecipitation and electrophoretic mobility shift assays to identify transcription factors that influence transcription of the FXN gene. We found that the transcription factors SRF and TFAP2 bind directly to FXN promoter sequences. SRF and TFAP2 binding sequences in the FXN promoter enhanced transcription from luciferase constructs, while mutagenesis of the predicted SRF or TFAP2 binding sites significantly decreased FXN promoter activity. Further analysis demonstrated that robust SRF- and TFAP2-mediated transcriptional activity was dependent on a regulatory element, located immediately downstream of the first FXN exon. Finally, over-expression of either SRF or TFAP2 significantly increased frataxin mRNA and protein levels in HEK293 cells, and frataxin mRNA levels were also elevated in SH-SY5Y cells and in Friedreich ataxia patient lymphoblasts transfected with SRF or TFAP2.We identified two transcription factors, SRF and TFAP2, as well as an intronic element encompassing EGR3-like sequence, that work together to regulate expression of the FXN gene. By providing new mechanistic insights into the molecular factors influencing frataxin expression, our results should aid in the discovery of new therapeutic targets for the treatment of Friedreich ataxia

    Caring Agent for the Call: The Lived Experience of Nurses as Call Center Agents

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    A number of registered nurses are working as call center agents instead of practicing their profession. This phenomenological inquiry aimed to understand and provide perspective on the lived experience of seven registered nurses, who worked as a call center agent for at least two years. Through intensive recorded interviews, the responses were initially clustered in ten. The initial five clusters were categorized into textural themes such a) ceasing opportunities vs chasing pavements; b) learning to adjust; c) deception and false images: seeing from inside out; d) reflection on the derailed career path ; e) self-fulfillment in the chosen path.&nbsp; The final five clusters were categorized into structural theme such as f) making ends meet; becoming the breadwinner; g) change vs tradition; h) gaining strength through challenges; i) eyes on the patient, ears on the phone; j) vulnerability of the strong.&nbsp; In conclusion, the lived experience of nurses working as call center agents provided self-fulfillment, through financial stability that enable them to provide for their family, personality and career growth, and the benefits received. They cope with the challenges encountered on this job by being competitive and having a strong personality, though two of the participants resorted to vices

    Kv7 Channels Can Function without Constitutive Calmodulin Tethering

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    M-channels are voltage-gated potassium channels composed of Kv7.2-7.5 subunits that serve as important regulators of neuronal excitability. Calmodulin binding is required for Kv7 channel function and mutations in Kv7.2 that disrupt calmodulin binding cause Benign Familial Neonatal Convulsions (BFNC), a dominantly inherited human epilepsy. On the basis that Kv7.2 mutants deficient in calmodulin binding are not functional, calmodulin has been defined as an auxiliary subunit of Kv7 channels. However, we have identified a presumably phosphomimetic mutation S511D that permits calmodulin-independent function. Thus, our data reveal that constitutive tethering of calmodulin is not required for Kv7 channel function

    Structure, Function, and Modification of the Voltage Sensor in Voltage-Gated Ion Channels

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    Targeted gene sanger sequencing should remain the first-tier genetic test for children suspected to have the five common X-linked inborn errors of immunity

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    DATA AVAILABILITY STATEMENT : The original contributions presented in the study are included in the article/Supplementary Material. Further inquiries can be directed to the corresponding author.To address inborn errors of immunity (IEI) which were underdiagnosed in resource-limited regions, our centre developed and offered free genetic testing for the most common IEI by Sanger sequencing (SS) since 2001. With the establishment of The Asian Primary Immunodeficiency (APID) Network in 2009, the awareness and definitive diagnosis of IEI were further improved with collaboration among centres caring for IEI patients from East and Southeast Asia. We also started to use whole exome sequencing (WES) for undiagnosed cases and further extended our collaboration with centres from South Asia and Africa. With the increased use of Next Generation Sequencing (NGS), we have shifted our diagnostic practice from SS to WES. However, SS was still one of the key diagnostic tools for IEI for the past two decades. Our centre has performed 2,024 IEI SS genetic tests, with in-house protocol designed specifically for 84 genes, in 1,376 patients with 744 identified to have disease-causing mutations (54.1%). The high diagnostic rate after just one round of targeted gene SS for each of the 5 common IEI (X-linked agammaglobulinemia (XLA) 77.4%, Wiskott–Aldrich syndrome (WAS) 69.2%, X-linked chronic granulomatous disease (XCGD) 59.5%, X-linked severe combined immunodeficiency (XSCID) 51.1%, and X-linked hyper-IgM syndrome (HIGM1) 58.1%) demonstrated targeted gene SS should remain the first-tier genetic test for the 5 common X-linked IEI.The Hong Kong Society for Relief of Disabled Children and Jeffrey Modell Foundation.http://www.frontiersin.org/Immunologyam2023Paediatrics and Child Healt

    Analytical model for a two-phase vacuum plume

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