Neurogenic cardiac outcome in patients after acute ischemic stroke: The brain and heart connection.

BACKGROUND: Neurogenic cardiac impairment can occur after acute ischemic stroke (AIS), but the mapping of the neuroanatomic correlation of stroke-related myocardial injury remains uncertain. This study aims to identify the association between cardiac outcomes and middle cerebral artery (MCA) ischemic stroke, with or without insular cortex involvement, as well as the impact of new-onset atrial fibrillation (AF) after AIS on recurrent stroke. METHODS: Serial measurements of high sensitivity troponin T (TnT), brain natriuretic peptide (BNP), electrocardiography (ECG), echocardiogram, and cardiac monitoring were performed on 415 patients with imaging confirmed MCA stroke, with or without insular involvement. Patients with renal failure, recent cardiovascular events, or congestive heart failure were excluded. RESULTS: One hundred fifteen patients (28%) had left MCA infarcts with insular involvement, 122 (29%) had right MCA infarcts involving insular cortex, and 178 (43%) had no insular involvement. Patients with left MCA stroke with insular involvement tended to exhibit higher BNP and TnI, and transient cardiac dysfunction, which mimicked Takotsubo cardiomyopathy in 10 patients with left ventricular ejection fraction (LVEF) of 20-40%. Incidence of new-onset AF was higher in right MCA stroke involving insula (39%) than left MCA involving insula (4%). Nine out of fifty-three patients with new-onset AF were not on anticoagulant therapy due to various reasons; none of them experienced recurrent AF or stroke during up to a 3-year follow-up period. Statistically significant correlations between BNP or TnT elevation and left insular infarcts, as well as the incidence of AF and right insular infarcts, were revealed using linear regression analysis. CONCLUSIONS: The present study demonstrated that acute left MCA stroke with insular involvement could cause transient cardiac dysfunction and elevated cardiac enzymes without persistent negative outcomes in the setting of health baseline cardiac condition. The incidence of new-onset AF was significantly higher in patients with right MCA stroke involving the insula. There was no increased risk of recurrent ischemic stroke in nine patients with newly developed AF who were not on anticoagulant therapy, which indicated a need for further research on presumed neurogenic AF and its management.

Quantification of bronchoalveolar neutrophil extracellular traps and phagocytosis in murine pneumonia.

The past two decades have witnessed a resurgence in neutrophil research, inspired in part by the discovery of neutrophil extracellular traps (NETs) and their myriad roles in health and disease. Within the lung, dysregulation of neutrophils and NETosis have been linked to an array of diseases including pneumonia, cystic fibrosis, acute respiratory distress syndrome (ARDS), chronic obstructive pulmonary disease (COPD), and severe asthma. However, our understanding of pathologic neutrophil responses in the lung remains incomplete. Two methodologic issues have contributed to this gap: first, an emphasis on studying neutrophils from blood rather than the lung and second, the technical difficulties of interrogating neutrophil responses in mice, which has largely restricted basic murine research to specialized laboratories. To address these limitations, we have developed a suite of techniques for studying neutrophil effector functions specifically in the mouse lung. These include ex vivo assays for phagocytosis and NETosis using bronchoalveolar neutrophils and in situ evaluation of NETosis in a murine model of pneumonia. Throughout, we have prioritized technical ease and robust, quantitative readouts. We hope these assays will help to standardize research on lung neutrophils and improve accessibility to this burgeoning field.

Severe respiratory viral infection induces procalcitonin in the absence of bacterial pneumonia.

INTRODUCTION: Procalcitonin expression is thought to be stimulated by bacteria and suppressed by viruses via interferon signalling. Consequently, during respiratory viral illness, clinicians often interpret elevated procalcitonin as evidence of bacterial coinfection, prompting antibiotic administration. We sought to evaluate the validity of this practice and the underlying assumption that viral infection inhibits procalcitonin synthesis. METHODS: We conducted a retrospective cohort study of patients hospitalised with pure viral infection (n=2075) versus bacterial coinfection (n=179). The ability of procalcitonin to distinguish these groups was assessed. In addition, procalcitonin and interferon gene expression were evaluated in murine and cellular models of influenza infection. RESULTS: Patients with bacterial coinfection had higher procalcitonin than those with pure viral infection, but also more severe disease and higher mortality (p<0.001). After matching for severity, the specificity of procalcitonin for bacterial coinfection dropped substantially, from 72% to 61%. In fact, receiver operating characteristic curve analysis showed that procalcitonin was a better indicator of multiple indices of severity (eg, organ failures and mortality) than of coinfection. Accordingly, patients with severe viral infection had elevated procalcitonin. In murine and cellular models of influenza infection, procalcitonin was also elevated despite bacteriologic sterility and correlated with markers of severity. Interferon signalling did not abrogate procalcitonin synthesis. DISCUSSION: These studies reveal that procalcitonin rises during pure viral infection in proportion to disease severity and is not suppressed by interferon signalling, in contrast to prior models of procalcitonin regulation. Applied clinically, our data suggest that procalcitonin represents a better indicator of disease severity than bacterial coinfection during viral respiratory infection.

Myopathic lamin mutations cause reductive stress and activate the nrf2/keap-1 pathway.

Mutations in the human LMNA gene cause muscular dystrophy by mechanisms that are incompletely understood. The LMNA gene encodes A-type lamins, intermediate filaments that form a network underlying the inner nuclear membrane, providing structural support for the nucleus and organizing the genome. To better understand the pathogenesis caused by mutant lamins, we performed a structural and functional analysis on LMNA missense mutations identified in muscular dystrophy patients. These mutations perturb the tertiary structure of the conserved A-type lamin Ig-fold domain. To identify the effects of these structural perturbations on lamin function, we modeled these mutations in Drosophila Lamin C and expressed the mutant lamins in muscle. We found that the structural perturbations had minimal dominant effects on nuclear stiffness, suggesting that the muscle pathology was not accompanied by major structural disruption of the peripheral nuclear lamina. However, subtle alterations in the lamina network and subnuclear reorganization of lamins remain possible. Affected muscles had cytoplasmic aggregation of lamins and additional nuclear envelope proteins. Transcription profiling revealed upregulation of many Nrf2 target genes. Nrf2 is normally sequestered in the cytoplasm by Keap-1. Under oxidative stress Nrf2 dissociates from Keap-1, translocates into the nucleus, and activates gene expression. Unexpectedly, biochemical analyses revealed high levels of reducing agents, indicative of reductive stress. The accumulation of cytoplasmic lamin aggregates correlated with elevated levels of the autophagy adaptor p62/SQSTM1, which also binds Keap-1, abrogating Nrf2 cytoplasmic sequestration, allowing Nrf2 nuclear translocation and target gene activation. Elevated p62/SQSTM1 and nuclear enrichment of Nrf2 were identified in muscle biopsies from the corresponding muscular dystrophy patients, validating the disease relevance of our Drosophila model. Thus, novel connections were made between mutant lamins and the Nrf2 signaling pathway, suggesting new avenues of therapeutic intervention that include regulation of protein folding and metabolism, as well as maintenance of redox homoeostasis.

Cementing Constrained Liners Into Secure Cementless Shells: A Minimum 15-Year Follow-Up Study.

BACKGROUND: The authors and others have previously described the technique of cementing constrained liners into secure cementless acetabular shells and reported the short-term, average 3.9-year follow-up, using that technique. The purpose of the present study was to report the minimum 15-year follow-up of this same cohort. METHODS: Between 1988 and 2000, 31 consecutive constrained liners of one design were cemented into well-fixed, well-positioned cementless acetabular shells at 3 institutions. Average age at surgery was 72 years (range, 31-91 years). Indications for the procedure were recurrent hip dislocation in 16 cases and intraoperative instability in 15 cases. Patients were evaluated for revision for failure of the device and revision for any reason. RESULTS: At minimum 15-year follow-up, there was 1 patient lost to follow-up. Three hips (9.7%) were revised for failure of the device and 5 hips (16.1%) were revised for any reason. CONCLUSION: At minimum 15-year follow-up, considering the complexity of cases, there was excellent medium-term durability of this construct.

Budding uninhibited by benzimidazoles-1 (BUB1) regulates EGFR signaling by reducing EGFR internalization.

EGFR signaling initiates upon ligand binding which leads to activation and internalization of the receptor-ligand complex. Here, we evaluated if BUB1 impacted EGFR signaling by regulating EGFR receptor internalization and activation. BUB1 was ablated genomically (siRNA) or biochemically (2OH-BNPP1) in cells. EGF ligand was used to initiate EGFR signaling while disuccinimidyl suberate (DSS) was used for cross linking cellular proteins. EGFR signaling was measured by western immunoblotting and receptor internalization was evaluated by fluorescent microscopy (pEGFR (pY1068) colocalization with early endosome marker EEA1). siRNA mediated BUB1 depletion led to an overall increase in total EGFR levels and more phospho-EGFR (Y845, Y1092, and Y1173) dimers while the amount of total EGFR (non-phospho) dimers remained unchanged. BUB1 inhibitor (BUB1i) decreased EGF mediated EGFR signaling including pEGFR Y845, pAKT S473 and pERK1/2 in a time dependent manner. Additionally, BUB1i also reduced EGF mediated pEGFR (Y845) dimers (asymmetric dimers) without affecting total EGFR dimers (symmetric dimers) indicating that dimerization of inactive EGFR is not affected by BUB1. Furthermore, BUB1i blocked EGF mediated EGFR degradation (increase in EGFR half-life) without impacting half-lives of HER2 or c-MET. BUB1i also reduced co-localization of pEGFR with EEA1 positive endosomes suggesting that BUB1 might modulate EGFR endocytosis. Our data provide evidence that BUB1 protein and its kinase activity may regulate EGFR activation, endocytosis, degradation, and downstream signaling without affecting other members of the receptor tyrosine kinase family.

Neuropsychiatric manifestations in adult-onset Still's disease.

Adult-onset Still's disease (AOSD) is an uncommon inflammatory condition characterised by a triad of fevers, arthralgias and a salmon-coloured rash. It is also strongly associated with high ferritin levels, whose role in its pathogenesis is not entirely clear. Central nervous system (CNS) manifestations are exceedingly rare in this disease, accounting for only a handful of reported cases. Herein, we describe a case of a 63-year-old woman who developed new-onset psychiatric symptoms in the months preceding her diagnosis. 2 months after her diagnosis, she experienced an exacerbation of psychiatric symptoms followed by new-onset seizures in conjunction with an acute lung infection. In addition, we discuss two other previously reported cases of AOSD patients with psychiatric symptoms as their initial presentation.

A 62-Year-Old Woman With Lung Cancer, Ulcerating Rash, and Rapidly Progressive Hypoxemia.

CASE PRESENTATION: A 62-year-old nonsmoking woman with no medical history initially presented with a 3-month history of rash. A painful, erythematous exanthem had progressed from her forehead, cheeks, and upper chest to her eyes (heliotrope rash) and hands, primarily involving the extensor surface finger joints with prominent digital ulceration.

TGFBR2 mediated phosphorylation of BUB1 at Ser-318 is required for transforming growth factor-ß signaling.

BUB1 (budding uninhibited by benzimidazoles-1) is required for efficient TGF-ß signaling, through its role in stabilizing the TGFBR1 and TGFBR2 complex. Here we demonstrate that TGFBR2 phosphorylates BUB1 at Serine-318, which is conserved in primates. S318 phosphorylation abrogates the interaction of BUB1 with TGFBR1 and SMAD2. Using BUB1 truncation domains (1-241, 241-482 and 482-723), we demonstrate that multiple contact points exist between BUB1 and TGF-ß signaling components and that these interactions are independent of the BUB1 tetratricopeptide repeat (TPR) domain. Moreover, substitutions in the middle domain (241-482) encompassing S318 reveals that efficient interaction with TGFBR2 occurs only in its dephosphorylated state (241-482 S318A). In contrast, the phospho-mimicking mutant (241-482 S318D) exhibits efficient binding with SMAD2 and its over-expression results in a decrease in TGFBR1-TGFBR2 and TGFBR1-SMAD2 interactions. These findings suggest that TGFBR2 mediated BUB1 phosphorylation at S318 may serve as a switch for the dissociation of the SMAD2-TGFBR complex, and therefore represents a regulatory event for TGF-ß signaling. Finally, we provide evidence that the BUB1-TGF-ß signaling axis may mediate aggressive phenotypes in a variety of cancers.

Rapid decline of seasonal influenza during the outbreak of COVID-19.

The implementation of public health measures during the #COVID19 pandemic may also help to reduce transmission of respiratory illnesses such as influenza https://bit.ly/2BmysRJ.

Medicare Coverage and Patient Out-of-Pocket Costs for Cardiovascular-Kidney-Metabolic Medications.

This cross-sectional study evaluates the association between Medicare coverage and patient out-of-pocket costs for cardiovascular-kidney-metabolic medications.

Increasing autophagy and blocking Nrf2 suppress laminopathy-induced age-dependent cardiac dysfunction and shortened lifespan.

Mutations in the human LMNA gene cause a collection of diseases known as laminopathies. These include myocardial diseases that exhibit age-dependent penetrance of dysrhythmias and heart failure. The LMNA gene encodes A-type lamins, intermediate filaments that support nuclear structure and organize the genome. Mechanisms by which mutant lamins cause age-dependent heart defects are not well understood. To address this issue, we modeled human disease-causing mutations in the Drosophila melanogaster Lamin C gene and expressed mutant Lamin C exclusively in the heart. This resulted in progressive cardiac dysfunction, loss of adipose tissue homeostasis, and a shortened adult lifespan. Within cardiac cells, mutant Lamin C aggregated in the cytoplasm, the CncC(Nrf2)/Keap1 redox sensing pathway was activated, mitochondria exhibited abnormal morphology, and the autophagy cargo receptor Ref2(P)/p62 was upregulated. Genetic analyses demonstrated that simultaneous over-expression of the autophagy kinase Atg1 gene and an RNAi against CncC eliminated the cytoplasmic protein aggregates, restored cardiac function, and lengthened lifespan. These data suggest that simultaneously increasing rates of autophagy and blocking the Nrf2/Keap1 pathway are a potential therapeutic strategy for cardiac laminopathies.

Quantitative and Dynamic Imaging of ATM Kinase Activity.

Ataxia telangiectasia mutated (ATM) is a serine/threonine kinase critical to the cellular DNA-damage response, including DNA double-strand breaks (DSBs). ATM activation results in the initiation of a complex cascade of events facilitating DNA damage repair, cell cycle checkpoint control, and survival. Traditionally, protein kinases have been analyzed in vitro using biochemical methods (kinase assays using purified proteins or immunological assays) requiring a large number of cells and cell lysis. Genetically encoded biosensors based on optical molecular imaging such as fluorescence or bioluminescence have been developed to enable interrogation of kinase activities in live cells with a high signal to background. We have genetically engineered a hybrid protein whose bioluminescent activity is dependent on the ATM-mediated phosphorylation of a substrate. The engineered protein consists of the split luciferase-based protein complementation pair with a CHK2 (a substrate for ATM kinase activity) target sequence and a phospho-serine/threonine-binding domain, FHA2, derived from yeast Rad53. Phosphorylation of the serine residue within the target sequence by ATM would lead to its interaction with the phospho-serine-binding domain, thereby preventing complementation of the split luciferase pair and loss of reporter activity. Bioluminescence imaging of reporter expressing cells in cultured plates or as mouse xenografts provides a quantitative surrogate for ATM kinase activity and therefore the cellular DNA damage response in a noninvasive, dynamic fashion.

Quantitative and Dynamic Imaging of ATM Kinase Activity by Bioluminescence Imaging.

Ataxia telangiectasia mutated (ATM) is a serine/threonine kinase critical to the cellular DNA damage response, including DNA double strand breaks (DSBs). ATM activation results in the initiation of a complex cascade of events facilitating DNA damage repair, cell cycle checkpoint control, and survival. Traditionally, protein kinases have been analyzed in vitro using biochemical methods (kinase assays using purified proteins or immunological assays) requiring a large number of cells and cell lysis. Genetically encoded biosensors based on optical molecular imaging such as fluorescence or bioluminescence have been developed to enable interrogation of kinase activities in live cells with a high signal to background. We have genetically engineered a hybrid protein whose bioluminescent activity is dependent on the ATM-mediated phosphorylation of a substrate. The engineered protein consists of the split luciferase-based protein complementation pair with a CHK2 (a substrate for ATM kinase activity) target sequence and a phospho-serine/threonine-binding domain, FHA2, derived from yeast Rad53. Phosphorylation of the serine residue within the target sequence by ATM would lead to its interaction with the phospho-serine-binding domain, thereby preventing complementation of the split luciferase pair and loss of reporter activity. Bioluminescence imaging of reporter-expressing cells in cultured plates or as mouse xenografts provides a quantitative surrogate for ATM kinase activity and therefore the cellular DNA damage response in a noninvasive, dynamic fashion.