Targeting Calpain-2-mediated Junctophilin-2 cleavage delays heart failure progression following myocardial infarction.

Coronary heart disease (CHD) is a prevalent cardiac disease that causes over 370,000 deaths annually in the USA. In CHD, occlusion of a coronary artery causes ischemia of the cardiac muscle, which results in myocardial infarction (MI). Junctophilin-2 (JPH2) is a membrane protein that ensures efficient calcium handling and proper excitation-contraction coupling. Studies have identified loss of JPH2 due to calpain-mediated proteolysis as a key pathogenic event in ischemia-induced heart failure (HF). Our findings show that calpain-2-mediated JPH2 cleavage yields increased levels of a C-terminal cleaved peptide (JPH2-CTP) in patients with ischemic cardiomyopathy and mice with experimental MI. We created a novel knock-in mouse model by removing residues 479-SPAGTPPQ-486 to prevent calpain-2-mediated cleavage at this site. Functional and molecular assessment of cardiac function post-MI in cleavage site deletion (CSD) mice showed preserved cardiac contractility and reduced dilation, reduced JPH2-CTP levels, attenuated adverse remodeling, improved T-tubular structure, and normalized SR Ca2+-handling. Adenovirus mediated calpain-2 knockdown in mice exhibited similar findings. Pulldown of CTP followed by proteomic analysis revealed valosin-containing protein (VCP) and BAG family molecular chaperone regulator 3 (BAG3) as novel binding partners of JPH2. Together, our findings suggest that blocking calpain-2-mediated JPH2 cleavage may be a promising new strategy for delaying the development of HF following MI.

T-Cell Immunity Against Severe Acute Respiratory Syndrome Coronavirus 2 Measured by an Interferon-γ Release Assay Is Strongly Associated With Patient Outcomes in Vaccinated Persons Hospitalized With Delta or Omicron Variants.

BACKGROUND: We measured T-cell and antibody responses to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in vaccinated patients hospitalized for coronavirus disease 2019 (COVID-19) and explored their potential value to predict outcomes. METHODS: This was a prospective, longitudinal study including vaccinated patients hospitalized with Delta and Omicron SARS-CoV-2 variants. TrimericS-IgG antibodies and SARS-CoV-2 T-cell response were measured using a specific quantitative interferon-γ release assay (IGRA). Primary outcome was all-cause 28-day mortality or need for intensive care unit (ICU) admission. Cox models were used to assess associations with outcomes. RESULTS: Of 181 individuals, 158 (87.3%) had detectable SARS-CoV-2 antibodies, 92 (50.8%) showed SARS-CoV-2-specific T-cell responses, and 87 (48.1%) had both responses. Patients who died within 28 days or were admitted to ICU were less likely to have both unspecific and specific T-cell responses in IGRA. In adjusted analyses (adjusted hazard ratio [95% confidence interval]), for the entire cohort, having both T-cell and antibody responses at admission (0.16 [.05-.58]) and Omicron variant (0.38 [.17-.87]) reduced the hazard of 28-day mortality or ICU admission, whereas higher Charlson comorbidity index score (1.27 [1.07-1.51]) and lower oxygen saturation to fraction of inspired oxygen ratio (2.36 [1.51-3.67]) increased the risk. CONCLUSIONS: Preexisting immunity against SARS-CoV-2 is strongly associated with patient outcomes in vaccinated individuals requiring hospital admission for COVID-19. Persons showing both T-cell and antibody responses have the lowest risk of severe outcomes.

Determinantes sociales asociados con ideación suicida durante la pandemia por Covid-19 en México.

OBJETIVO: Estimar la prevalencia de la ideación suicida (IS) y su asociación con los determinantes sociales (DS) en la pobla-ción mexicana durante la pandemia de Covid-19. Material y métodos. Datos de la encuesta de Atención Psicológica a Distancia para la Salud Mental debido a la Contingencia por Covid-19 obtenidos durante 2020. La muestra fue de 79 665. Se realizaron modelos de regresión logística obteniendo razones de momios (RM) con intervalos de confianza del 95% (IC95%). RESULTADOS: La prevalencia de IS fue de 17.1% (mujeres:18.8% y hombres: 14.4%). Principales DS asociados fueron: ser mujer (RM=1.11; IC95% 1.06,1.13), mujeres jóvenes (RM=1.30; IC95% 1.09,1.54), escolaridad (RM=1.89; IC95% 1.14,3.12), soltera(o) (RM= 1.31; IC95% 1.24,1.38), desempleo (RM= 2.33; IC95% 2.21,2.45), distanciamiento social (RM 1.81; IC95%1.68,1.96), vivir solo (RM 1.18; IC95% 1.10,1.27), pérdida de familiar por Covid-19 (RM= 1.41; IC95%1.30,1.54), tener un diagnóstico de depresión (RM= 5.72; IC95% 5.41,6.05), ser víctima de violencia física (RM=2.71; IC95% 2.49,2.95), consumo excesivo de alcohol (RM=1.68; IC95%1.58,1.79) y drogas (RM= 3.13; IC95% 2.88,3.41), y sospecha o diagnóstico de Covid-19 (RM=1.79; IC95% 1.67,1.89). CONCLUSIONES: La prevalencia de IS durante la pandemia por Covid-19 fue elevada; se discute la relevancia de los DS estructurales e intermedios que influyen en la IS.

Eventos de vida estresantes y su efecto en la conducta suicida en mujeres durante la pandemia por Covid-19 en México.

OBJETIVO: Analizar la estructura factorial, la validez convergente y divergente de la Escala Columbia de Severidad Suicida (CSSRS) y el Cuestionario de Eventos de Vida Estresantes (EVE) y medir la asociación entre EVE y conducta suicida (CS) en mujeres mexicanas durante la pandemia por Covid-19. Material y métodos. Se usaron datos de 2 398 mujeres que participaron en un estudio multicéntrico, realizado en México entre mayo y octubre de 2021. La información se recolectó mediante un cuestionario en línea que incluyó la CSSRS y el EVE. Se hizo un análisis factorial confirmatorio para valorar el ajuste de los modelos. RESULTADOS: El modelo final mostró asociación entre los EVE y la CS, y tuvo a la violencia como variable central. Dicho modelo presentó un ajuste adecuado (CFI = 0.950, IFI = 0.950, MFI = 0.975, RMSEA = 0.031, CI RMSEA = 0.026-0.036). CONCLUSIONES: La pandemia por Covid-19 evidenció la necesidad de crear e implementar estrategias que promuevan el cuidado de la salud mental, reduzcan la exposición a la violencia y faciliten los procesos de duelo para prevenir la CS en mujeres mexicanas.

Partial Genetic Deletion of Klotho Aggravates Cardiac Calcium Mishandling in Acute Kidney Injury.

Acute kidney injury (AKI) is associated with an elevated risk of cardiovascular major events and mortality. The pathophysiological mechanisms underlying the complex cardiorenal network interaction remain unresolved. It is known that the presence of AKI and its evolution are significantly associated with an alteration in the anti-aging factor klotho expression. However, it is unknown whether a klotho deficiency might aggravate cardiac damage after AKI. We examined intracellular calcium (Ca2+) handling in native ventricular isolated cardiomyocytes from wild-type (+/+) and heterozygous hypomorphic mice for the klotho gene (+/kl) in which an overdose of folic acid was administered to induce AKI. Twenty-four hours after AKI induction, cardiomyocyte contraction was decreased in mice with the partial deletion of klotho expression (heterozygous hypomorphic klotho named +/kl). This was accompanied by alterations in Ca2+ transients during systole and an impairment of sarco/endoplasmic reticulum Ca2+-ATPase (SERCA2a) function in +/kl mice after AKI induction. Moreover, Ca2+ spark frequency and the incidence of Ca2+ pro-arrhythmic events were greater in cardiomyocytes from heterozygous hypomorphic klotho compared to wild-type mice after AKI. A decrease in klotho expression plays a role in cardiorenal damage aggravating cardiac Ca2+ mishandling after an AKI, providing the basis for future targeted approaches directed to control klotho expression as novel therapeutic strategies to reduce the cardiac burden that affects AKI patients.

Clinical Performance of a Standardized Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) Interferon-γ Release Assay for Simple Detection of T-Cell Responses After Infection or Vaccination.

BACKGROUND: We evaluated a standardized interferon-γ (IFN-γ) release assay (IGRA) for detection of T-cell immune response after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection or vaccination. METHODS: This prospective study included patients with coronavirus disease 2019 (COVID-19) with different severity of illness and follow-up (FU), vaccinated subjects, and healthy unvaccinated persons. SARS-CoV-2 T-cell response was measured using a specific quantitative IGRA in whole blood (Euroimmun, Germany) and TrimericS-IgG and neutralizing antibodies with validated serological platforms. Positivity of reverse transcription-polymerase chain reaction or vaccination was considered as the reference standard. RESULTS: A total of 239 individuals were included (152 convalescent, 54 vaccinated, and 33 uninfected unvaccinated). Overall sensitivity, specificity, and positive- and negative-predictive values (95% confidence interval) of the IGRA were 81.1% (74.9-86%), 90.9% (74.5-97.6%), 98.2% (94.5-99.5%), and 43.5% (31.8-55.9%), respectively. All vaccinated SARS-CoV-2-naive subjects had positive IGRA at 3 months. In convalescent subjects the magnitude of IFN-γ responses and IGRA accuracy varied according to disease severity and duration of FU, with the best performance in patients with severe COVID-19 at 3 months and the worst in those with mild disease at 12 months. The greatest contribution of IGRA to serological tests was observed in patients with mild disease and long-term FU (incremental difference, 30.4%). CONCLUSIONS: The IGRA was a reliable method of quantifying T-cell response after SARS-COV-2 infection or vaccination. In convalescent patients, the sensitivity is largely dependent on disease severity and time since primary infection. The assay is more likely to add clinical value to serology in patients with mild infections.

Murine models of uremic cardiomyopathy as a necessary tool to unravel mechanisms involved in cardiorenal syndrome.

Chronic kidney disease (CKD) and cardiovascular disease frequently run in parallel. Herein, Soppert et al. provide an interesting meta-analysis of the effects of CKD on cardiac remodeling and/or function in mice based on the model, strain, and duration. The authors sought to determine the most appropriate experimental model to unravel the specific underlying pathologic mechanisms involved in cardiac damage in CKD (single hit) or to investigate new strategies to prevent CKD-induced cardiovascular disease (multifactorial hits representing cardiovascular comorbidities of patients with CKD).

Soluble α-klotho and heparin modulate the pathologic cardiac actions of fibroblast growth factor 23 in chronic kidney disease.

Fibroblast growth factor (FGF) 23 is a phosphate-regulating hormone that is elevated in patients with chronic kidney disease and associated with cardiovascular mortality. Experimental studies showed that elevated FGF23 levels induce cardiac hypertrophy by targeting cardiac myocytes via FGF receptor isoform 4 (FGFR4). A recent structural analysis revealed that the complex of FGF23 and FGFR1, the physiologic FGF23 receptor in the kidney, includes soluble α-klotho (klotho) and heparin, which both act as co-factors for FGF23/FGFR1 signaling. Here, we investigated whether soluble klotho, a circulating protein with cardio-protective properties, and heparin, a factor that is routinely infused into patients with kidney failure during the hemodialysis procedure, regulate FGF23/FGFR4 signaling and effects in cardiac myocytes. We developed a plate-based binding assay to quantify affinities of specific FGF23/FGFR interactions and found that soluble klotho and heparin mediate FGF23 binding to distinct FGFR isoforms. Heparin specifically mediated FGF23 binding to FGFR4 and increased FGF23 stimulatory effects on hypertrophic growth and contractility in isolated cardiac myocytes. When repetitively injected into two different mouse models with elevated serum FGF23 levels, heparin aggravated cardiac hypertrophy. We also developed a novel procedure for the synthesis and purification of recombinant soluble klotho, which showed anti-hypertrophic effects in FGF23-treated cardiac myocytes. Thus, soluble klotho and heparin act as independent FGF23 co-receptors with opposite effects on the pathologic actions of FGF23, with soluble klotho reducing and heparin increasing FGF23-induced cardiac hypertrophy. Hence, whether heparin injections during hemodialysis in patients with extremely high serum FGF23 levels contribute to their high rates of cardiovascular events and mortality remains to be studied.

The anti-aging factor Klotho protects against acquired long QT syndrome induced by uremia and promoted by fibroblast growth factor 23.

BACKGROUND: Chronic kidney disease (CKD) is associated with increased propensity for arrhythmias. In this context, ventricular repolarization alterations have been shown to predispose to fatal arrhythmias and sudden cardiac death. Between mineral bone disturbances in CKD patients, increased fibroblast growth factor (FGF) 23 and decreased Klotho are emerging as important effectors of cardiovascular disease. However, the relationship between imbalanced FGF23-Klotho axis and the development of cardiac arrhythmias in CKD remains unknown. METHODS: We carried out a translational approach to study the relationship between the FGF23-Klotho signaling axis and acquired long QT syndrome in CKD-associated uremia. FGF23 levels and cardiac repolarization dynamics were analyzed in patients with dialysis-dependent CKD and in uremic mouse models of 5/6 nephrectomy (Nfx) and Klotho deficiency (hypomorphism), which show very high systemic FGF23 levels. RESULTS: Patients in the top quartile of FGF23 levels had a higher occurrence of very long QT intervals (> 490 ms) than peers in the lowest quartile. Experimentally, FGF23 induced QT prolongation in healthy mice. Similarly, alterations in cardiac repolarization and QT prolongation were observed in Nfx mice and in Klotho hypomorphic mice. QT prolongation in Nfx mice was explained by a significant decrease in the fast transient outward potassium (K+) current (Itof), caused by the downregulation of K+ channel 4.2 subunit (Kv4.2) expression. Kv4.2 expression was also significantly reduced in ventricular cardiomyocytes exposed to FGF23. Enhancing Klotho availability prevented both long QT prolongation and reduced Itof current. Likewise, administration of recombinant Klotho blocked the downregulation of Kv4.2 expression in Nfx mice and in FGF23-exposed cardiomyocytes. CONCLUSION: The FGF23-Klotho axis emerges as a new therapeutic target to prevent acquired long QT syndrome in uremia by minimizing the predisposition to potentially fatal ventricular arrhythmias and sudden cardiac death in patients with CKD.

Survival benefit of remdesivir in hospitalized COVID-19 patients with high SARS-CoV-2 viral loads and low-grade systemic inflammation.

OBJECTIVES: To assess the benefits of remdesivir in hospitalized COVID-19 patients receiving combined immunomodulatory therapy (CIT) with dexamethasone and tocilizumab. METHODS: This was a cohort study of microbiologically confirmed COVID-19 hospitalized patients. The primary outcome was all-cause 28 day mortality. Secondary outcomes were need for invasive mechanical ventilation (IMV) and IMV/death. Subgroup analyses according to SARS-CoV-2 cycle threshold (Ct) values and inflammation biomarkers were performed. Multivariable marginal structural Cox proportional hazards regression models were used to analyse the association between remdesivir therapy and the risk of outcomes of interest. RESULTS: Of 1368 hospitalized patients treated with corticosteroids, 1014 (74%) also received tocilizumab, 866 (63%) remdesivir and 767 (56%) tocilizumab + remdesivir. The 28 day mortality was 9% in the overall cohort, with an adjusted HR (aHR) of 0.32 (95% CI = 0.17-0.59) for patients receiving CIT. In the latter group, the 28 day mortality was 6.5%, with an aHR of 1.11 (95% CI = 0.57-2.16) for remdesivir use and there were no differences in secondary outcomes. The risk of primary and secondary outcomes with remdesivir differed by Ct and C-reactive protein (CRP) levels in patients receiving CIT: for 28 day mortality, the aHR was 0.48 (95% CI = 0.21-1.11) for Ct <25, 0.12 (95% CI = 0.02-0.66) for Ct <25 and <5 day symptom duration and 0.13 (95% CI = 0.03-0.50) for CRP <38 mg/L; for IMV and IMV/death, the aHR was 0.32 (95% CI = 0.13-0.77) and 0.33 (95% CI = 0.17-0.63), respectively, in patients with Ct <25. CONCLUSIONS: The benefits of remdesivir administered with dexamethasone and tocilizumab in hospitalized COVID-19 patients differ depending on Ct and CRP. Remdesivir decreases the risk of mortality and need for IMV in patients with high viral loads and low-grade systemic inflammation.

Bilateral Mandibular Pseudoarthrosis: A Rare Complication after Orthognathic Surgery.

ABSTRACT: Orthognathic surgery to treat dentofacial discrepancies has become an increasingly common elective procedure in sur-gical practices. Despite its numerous advantages such as improved aesthetics and masticatory and respiratory function, some complications and unfavorable results can be observed. Pseudoarthrosis after orthognathic surgery is a rare complication and is little reported in the literature. Pseudoarthrosis is characterized by an increasing occlusal worsening associated with bone mobility and pain. Due to the low incidence of pseudoarthrosis, it is necessary to study its involvement to elucidate its etiology and treatment. The aim of this work was to report a clinical case of bilateral mandibular pseudoarthrosis after orthognathic surgery, where multiple interventions and prolonged treatment time were necessary until the case was concluded. The precise diagnosis associated with the choice of the most effective treatment based on the literature proved to be essential for the management of this complication.

Unilateral Acute Renal Ischemia-Reperfusion Injury Induces Cardiac Dysfunction through Intracellular Calcium Mishandling.

BACKGROUND: Acute renal failure (ARF) following renal ischemia-reperfusion (I/R) injury is considered a relevant risk factor for cardiac damage, but the underlying mechanisms, particularly those triggered at cardiomyocyte level, are unknown. METHODS: We examined intracellular Ca2+ dynamics in adult ventricular cardiomyocytes isolated from C57BL/6 mice 7 or 15 days following unilateral renal I/R. RESULTS: After 7 days of I/R, the cell contraction was significantly lower in cardiomyocytes compared to sham-treated mice. It was accompanied by a significant decrease in both systolic Ca2+ transients and sarco/endoplasmic reticulum Ca2+-ATPase (SERCA2a) activity measured as Ca2+ transients decay. Moreover, the incidence of pro-arrhythmic events, measured as the number of Ca2+ sparks, waves or automatic Ca2+ transients, was greater in cardiomyocytes from mice 7 days after I/R than from sham-treated mice. Ca2+ mishandling related to systolic Ca2+ transients and contraction were recovered to sham values 15 days after I/R, but Ca2+ sparks frequency and arrhythmic events remained elevated. CONCLUSIONS: Renal I/R injury causes a cardiomyocyte Ca2+ cycle dysfunction at medium (contraction-relaxation dysfunction) and long term (Ca2+ leak), after 7 and 15 days of renal reperfusion, respectively.

Performance of Saliva Specimens for the Molecular Detection of SARS-CoV-2 in the Community Setting: Does Sample Collection Method Matter?

Data on the performance of saliva specimens for diagnosing coronavirus disease 2019 (COVID-19) in ambulatory patients are scarce and inconsistent. We assessed saliva-based specimens for detecting severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by reverse transcriptase PCR (RT-PCR) in the community setting and compared three different collection methods. This prospective study was conducted in three primary care centers. RT-PCR was performed on paired nasopharyngeal swabs (NPS) and saliva samples collected from outpatients with a broad clinical spectrum of illness. To assess differences in collection methods, saliva specimens were obtained in a different way in each of the participating centers: supervised collection (SVC), oropharyngeal washing (OPW), and self-collection (SC). Pairs of NPS and saliva samples from 577 patients (median age, 39 years; 44% men; 42% asymptomatic) were collected and tested, and 120 (20.8%) gave positive results. The overall agreement with NPS results and kappa coefficients (κ) for saliva samples obtained by SVC, OPW, and SC were 95% (κ = 0.85), 93.4% (κ = 0.76), and 93.3% (κ = 0.76), respectively. The sensitivities (95% confidence intervals [95% CI]) of the saliva specimens ranged from 86% (72.6% to 93.7%) for SVC to 66.7% (50.4% to 80%) for SC samples. Sensitivity was higher for samples with lower cycle threshold (CT ) values. The best RT-PCR performance was observed for SVC, with sensitivities (95% CI) of 100% (85.9% to 100%) in symptomatic individuals and 88.9% (50.7% to 99.4%) in asymptomatic individuals at CT values of ≤30. We conclude that saliva is an acceptable specimen for the detection of SARS-CoV-2 in the community setting. Specimens collected under supervision perform comparably to NPS and can effectively identify individuals at higher risk of transmission under real-life conditions.

Genetic Deletion of NOD1 Prevents Cardiac Ca2+ Mishandling Induced by Experimental Chronic Kidney Disease.

Risk of cardiovascular disease (CVD) increases considerably as renal function declines in chronic kidney disease (CKD). Nucleotide-binding oligomerization domain-containing protein 1 (NOD1) has emerged as a novel innate immune receptor involved in both CVD and CKD. Following activation, NOD1 undergoes a conformational change that allows the activation of the receptor-interacting serine/threonine protein kinase 2 (RIP2), promoting an inflammatory response. We evaluated whether the genetic deficiency of Nod1 or Rip2 in mice could prevent cardiac Ca2+ mishandling induced by sixth nephrectomy (Nx), a model of CKD. We examined intracellular Ca2+ dynamics in cardiomyocytes from Wild-type (Wt), Nod1-/- and Rip2-/- sham-operated or nephrectomized mice. Compared with Wt cardiomyocytes, Wt-Nx cells showed an impairment in the properties and kinetics of the intracellular Ca2+ transients, a reduction in both cell shortening and sarcoplasmic reticulum Ca2+ load, together with an increase in diastolic Ca2+ leak. Cardiomyocytes from Nod1-/--Nx and Rip2-/--Nx mice showed a significant amelioration in Ca2+ mishandling without modifying the kidney impairment induced by Nx. In conclusion, Nod1 and Rip2 deficiency prevents the intracellular Ca2+ mishandling induced by experimental CKD, unveiling new innate immune targets for the development of innovative therapeutic strategies to reduce cardiac complications in patients with CKD.

Fibroblast growth factor-23 promotes rhythm alterations and contractile dysfunction in adult ventricular cardiomyocytes.

BACKGROUND: Cardiac dysfunction and arrhythmia are common and onerous cardiovascular events in end-stage renal disease (ESRD) patients, especially those on dialysis. Fibroblast growth factor (FGF)-23 is a phosphate-regulating hormone whose levels dramatically increase as renal function declines. Beyond its role in phosphorus homeostasis, FGF-23 may elicit a direct effect on the heart. Whether FGF-23 modulates ventricular cardiac rhythm is unknown, prompting us to study its role on excitation-contraction (EC) coupling. METHODS: We examined FGF-23 in vitro actions on EC coupling in adult rat native ventricular cardiomyocytes using patch clamp and confocal microscopy and in vivo actions on cardiac rhythm using electrocardiogram. RESULTS: Compared with vehicle treatment, FGF-23 induced a significant decrease in rat cardiomyocyte contraction, L-type Ca2+ current, systolic Ca2+ transients and sarcoplasmic reticulum (SR) load and SR Ca2+-adenosine triphosphatase 2a pump activity. FGF-23 induced pro-arrhythmogenic activity in vitro and in vivo as automatic cardiomyocyte extracontractions and premature ventricular contractions. Diastolic spontaneous Ca2+ leak (sparks and waves) was significantly increased by FGF-23 via the calmodulin kinase type II (CaMKII)-dependent pathway related to hyperphosphorylation of ryanodine receptors at the CaMKII site Ser2814. Both contraction dysfunction and spontaneous pro-arrhythmic Ca2+ events induced by FGF-23 were blocked by soluble Klotho (sKlotho). CONCLUSIONS: Our results show that FGF-23 reduces contractility and enhances arrhythmogenicity through intracellular Ca2+ mishandling. Blocking its actions on the heart by improving sKlotho bioavailability may enhance cardiac function and reduce arrhythmic events frequently observed in ESRD.

PTH, vitamin D, and the FGF-23-klotho axis and heart: Going beyond the confines of nephrology.

BACKGROUND: Profound disturbances in mineral metabolism are closely linked to the progression of chronic kidney disease. However, increasing clinical and experimental evidence indicates that alterations in phosphate homoeostasis could have an even stronger impact on the heart. AIM: The aim of this review is to provide the reader with an update of how alterations in mineral metabolism are related to direct and indirect cardiotoxic effects beyond the nephrology setting. RESULTS: Evidence exists that alterations in mineral metabolism that are related to changes in parathyroid hormone (PTH), vitamin D, and the FGF-23-klotho axis have direct pathological consequences for the heart. Alterations in plasma PTH levels are associated with cardiac dysfunction and detrimental cardiac remodelling. Several clinical studies have associated vitamin D deficiency with the prevalence of cardiovascular disease (CV) and its risk factors. Recent evidences support deleterious direct and nonphosphaturic effects of FGF-23 on the heart as hypertrophy development. In contrast, reduced systemic klotho levels are related to CV damage, at least when advanced age is present. In addition, we discuss how these mineral metabolism molecules can counteract each other in some situations, in the context of failed clinical trials on cardiac protection as is the case of vitamin D supplementation. CONCLUSIONS: Among all mineral components, an increase in systemic FGF-23 levels is considered to have the greatest CV impact and risk. However, it is quite possible that many intracellular mechanisms mediated by FGF-23, especially those related to cardiomyocyte function, remain to be discovered.

Evaluation of the Virclia® automated chemiluminescent immunoassay system for diagnosing pneumonia caused by Mycoplasma pneumoniae.

BACKGROUND: Mycoplasma pneumoniae is considered an important etiologic agent of community-acquired pneumonia (CAP) in outpatients. We aimed to evaluate the diagnostic accuracy of a quick automated chemiluminescent immunoassay (CLIA) for M. pneumoniae in a population-based prospective study of CAP. METHODS: A total of 137 outpatients diagnosed with CAP were included in the study. Acute- and convalescent phase sera were analyzed for IgG and IgM to M. pneumoniae with both CLIA (VirClia® ) and ELISA immunoassays. Conventional serological criteria by quantitative ELISA were considered as reference standard. Sensitivity and specificity of the assay were assessed with the construction of receiver operating characteristic (ROC) curves, and the kappa index was used to evaluate the accuracy of the IgG and IgM determinations in the acute phase. RESULTS: Thirty-eight patients were diagnosed with pneumonia by M. pneumoniae. ROC curves for IgG and IgM of convalescent and acute phase (C/A) quotients by the CLIA and ELISA assays were comparable. Specifically, for the CLIA, the best C/A quotient for IgG was 2.617 (sensitivity, 94.9%; specificity, 99.9%), and for IgM 1.400 (sensitivity, 65.8%; specificity, 100%). Regarding the acute phase, the best diagnostic accuracy for the CLIA was obtained with an IgG index of 1.120 (sensitivity, 89.5%; specificity, 73.7%). The CLIA was very simple to execute and required a minimum sample handling. CONCLUSION: The accuracy of the Virclia® assay for the diagnosis of M. pneumoniae infection in outpatients with CAP was equivalent to the quantitative ELISA. The CLIA was quicker to perform and displayed better analytic workability than conventional ELISA.

Long COVID across SARS-CoV-2 variants, lineages, and sublineages.

This prospective study aimed to determine the prevalence of long COVID in patients hospitalized for SARS-CoV-2 infection from March 2020 to July 2022 and assess the impact of different viral lineages. A total of 2,524 patients were followed up for 12 months, with persistent symptoms reported in 35.2% at one month, decreasing thereafter. Omicron variant patients initially showed higher symptom intensity, but this trend diminished over time. Certain viral lineages, notably Delta lineages AY.126 and AY.43, and Omicron sublineages BA.1.17, BA.2.56, and BA.5.1, consistently correlated with more severe symptoms. Overall, long COVID prevalence and severity were similar across SARS-CoV-2 variants. Specific lineages may influence post-COVID sequelae persistence and severity.

In Vivo Cardiac Electrophysiology in Mice: Determination of Atrial and Ventricular Arrhythmic Substrates.

Cardiac arrhythmias are a common cardiac condition that might lead to fatal outcomes. A better understanding of the molecular and cellular basis of arrhythmia mechanisms is necessary for the development of better treatment modalities. To aid these efforts, various mouse models have been developed for studying cardiac arrhythmias. Both genetic and surgical mouse models are commonly used to assess the incidence and mechanisms of arrhythmias. Since spontaneous arrhythmias are uncommon in healthy young mice, intracardiac programmed electrical stimulation (PES) can be performed to assess the susceptibility to pacing-induced arrhythmias and uncover the possible presence of a proarrhythmogenic substrate. This procedure is performed by positioning an octopolar catheter inside the right atrium and ventricle of the heart through the right jugular vein. PES can provide insights into atrial and ventricular electrical activity and reveal whether atrial and/or ventricular arrhythmias are present or can be induced. Here, we explain detailed procedures used to perform this technique, possible troubleshooting scenarios, and methods to interpret the results obtained. © 2024 Wiley Periodicals LLC. Basic Protocol: Programmed electrical stimulation in mice.