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BACKGROUND: Foreign body ingestion is a common clinical problem. The upper esophagus is the most common site of foreign body, accounting for more than 75% of all cases, but cases with a foreign body in the duodenal papilla or common bile duct are rarely reported. CASE PRESENTATION: Herein, we report a rare case that a patient's abdominal pain resembling gastric ulcer was caused by a 3 cm long fishbone inserted into the duodenal papilla. CONCLUSION: Fishbone inserted into the duodenal papilla can cause an abdominal pain resembling gastric ulcer. Endoscopy is useful for the diagnosis and treatment of fishbone ingestion in clinical.
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Corpos Estranhos , Úlcera Gástrica , Dor Abdominal/etiologia , Duodeno/diagnóstico por imagem , Ingestão de Alimentos , Corpos Estranhos/diagnóstico , Corpos Estranhos/diagnóstico por imagem , Humanos , Úlcera Gástrica/etiologiaRESUMO
Colistin is considered a last-resort antibiotic against most gram-negative bacteria. Recent discoveries of a plasmid-mediated, transferable mobilized colistin-resistance gene ( mcr-1) on all continents have heralded the imminent emergence of pan-drug-resistant superbacteria. The inner-membrane protein MCR-1 can catalyze the transfer of phosphoethanolamine (PEA) to lipid A, resulting in colistin resistance. However, little is known about the mechanism, and few drugs exist to address this issue. We present crystal structures revealing the MCR-1 catalytic domain (cMCR-1) as a monozinc metalloprotein with ethanolamine (ETA) and d-glucose, respectively, thus highlighting 2 possible substrate-binding pockets in the MCR-1-catalyzed PEA transfer reaction. Mutation of the residues involved in ETA and d-glucose binding impairs colistin resistance in recombinant Escherichia coli containing full-length MCR-1. Partial analogs of the substrate are used for cocrystallization with cMCR-1, providing valuable information about the family of PEA transferases. One of the analogs, ETA, causes clear inhibition of polymyxin B resistance, highlighting its potential for drug development. These data demonstrate the crucial role of the PEA- and lipid A-binding pockets and provide novel insights into the structure-based mechanisms, important drug-target hot spots, and a drug template for further drug development to combat the urgent, rising threat of MCR-1-mediated antibiotic resistance.-Wei, P., Song, G., Shi, M., Zhou, Y., Liu, Y., Lei, J., Chen, P., Yin, L. Substrate analog interaction with MCR-1 offers insight into the rising threat of the plasmid-mediated transferable colistin resistance.
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Colistina/química , Farmacorresistência Bacteriana , Proteínas de Escherichia coli/química , Escherichia coli/enzimologia , Plasmídeos , Catálise , Colistina/farmacologia , Proteínas de Escherichia coli/metabolismo , Etanolaminas/química , Etanolaminas/metabolismo , Lipídeo A/biossíntese , Lipídeo A/química , Domínios ProteicosRESUMO
The manufacturing processes in chip industries are complex, and many kinds of raw materials and solvents of different nature are used, most of which are highly toxic and dangerous. During the machine preventive maintenance period, these toxic and harmful substances will escape from the sealed reaction chamber to the clean workshop environment and endanger the health of the workers on-site, resulting in occupational diseases. From the perspective of prevention, the spread and prediction of hydrochloric acid (HCl) that escaped from the metal-etching chamber during maintenance were studied in this article. The computational fluid dynamics technology was used for a three-dimensional numerical simulation of the indoor air velocity field and the HCl concentration field, and the simulation results were then compared with the on-site monitoring data to verify the correctness and feasibility. The occupational hazards and control measures were analyzed based on the numerical simulation, and the optimal control measure was obtained. In this article, using the method of ambient air to analyze the occupational exposure can provide a new idea to the field of occupational health research in the integrated circuit industry and had theoretical and practical significance.
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Substâncias Perigosas/química , Ácido Clorídrico/química , Hidrodinâmica , Exposição Ocupacional/análise , Simulação por Computador , SemicondutoresRESUMO
Timothy syndrome, an extremely rare disease, is closely associated with a mutation in CACNA1C gene, which encodes the cardiac L-type voltage-gated calcium channel (Cav1.2). In this study, we generated a human induced pluripotent stem cell (iPSC) line from a Timothy syndrome infant carrying heterozygous CACNA1C mutation (transcript variant NM_000719.7c.1216G>A: p.G406R). The generated iPSC line showed typical stem cell morphology, positively expressed pluripotency and proliferation markers, normal karyotype, and trilineage differentiation potential. Therefore, this patient-specific iPSC can be of great significance in investigating the mechanisms underlying Timothy syndrome, and hence establishing effective intervention strategies.
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Transtorno Autístico , Canais de Cálcio Tipo L , Heterozigoto , Células-Tronco Pluripotentes Induzidas , Síndrome do QT Longo , Sindactilia , Humanos , Canais de Cálcio Tipo L/genética , Canais de Cálcio Tipo L/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Sindactilia/genética , Sindactilia/patologia , Síndrome do QT Longo/genética , Síndrome do QT Longo/patologia , Síndrome do QT Longo/metabolismo , Transtorno Autístico/genética , Transtorno Autístico/patologia , Mutação , Linhagem Celular , Diferenciação Celular , LactenteRESUMO
The study aimed to investigate the influence of flaxseed-derived diglyceride-based high internal phase Pickering emulsions (HIPPE) at different levels (0%, 10%, 20%, 30%, 40%, and 50%) on the rheological and physicochemical properties of myofibrillar protein (MPs) gels. The study indicated that with increasing HIPPE levels, there was a significant increase in whiteness while a decrease in water-holding capacity. The gels with 10% HIPPE levels had higher ionic bonds, while those with 40% and 50% HIPPE levels showed higher hydrogen bonds. By increasing HIPPE levels in the formation of MP gels, the T2 relaxation time was found to decrease. Additionally, in all MP gels, G' values were significantly higher than G" values over time. Adding lower contents of HIPPE levels resulted in a more compact microstructure. These findings indicate that flaxseed-derived diglyceride-based HIPPEs could be utilized as fat substitutes in meat products to enhance their nutritional quality.
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Emulsões , Linho , Géis , Animais , Emulsões/química , Linho/química , Géis/química , Produtos da Carne/análise , Proteínas Musculares/química , Miofibrilas/química , ReologiaRESUMO
The study aimed to fabricate healthier beef burgers using high internal phase Pickering emulsion (HIPPE) as animal fat substitute. In this context, HIPPE stabilized by modified soy protein isolates was produced with flaxseed-derived diglycerides (DAGs). Beef burgers were prepared by substituting beef backfat with HIPPE at varying levels (0%, 25%, 50%, 75%, and 100%). Reformulated burgers showed a significant decrease in WHC (from 89.75 to 77.38%), pH (from 5.73 to 5.58), L* values (from 53.5 to 44.5), and b* values (22.9 to 21.8), while a significant increase in a* values (from 24.4 to 6.7), cooking loss (from 20.25 to 30.62), and cooking shrinkage (from 11.27 to 13.05). Texture attributes, including hardness, chewiness, and gumminess, decreased up to 50% fat substitution and increased with increasing levels of fat substitution. Moreover, the rheological properties (G' and G'') and T2 relaxation time were increased with increasing fat replacement. The reformulation with HIPPE resulted in a decrease in SFA (from 3896 to 1712 mg/100 g), ω-6/ω-3 ratio (from 5.29 to 0.47), atherogenic index (from 0.57 to 0.13), and thrombogenic index (from 1.46 to 0.15) and increase in PUFA/SFA ratio (from 0.20 to 2.79). Notably, burgers with 50% fat substitution were more preferred regarding tenderness, while those with 100% fat substitution obtained higher scores for color and flavor than all other treatments. In conclusion, 50% fat replacement using flaxseed-derived diglyceride-based HIPPE improved beef burgers' textural profile and fatty acid composition without compromising the sensory characteristics.
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Linho , Animais , Bovinos , Emulsões/química , Diglicerídeos , Culinária , Ácidos Graxos/análiseRESUMO
Pompe disease (PD) is a rare autosomal recessive disorder that presents with progressive hypertrophic cardiomyopathy. However, the detailed mechanism remains clarified. Herein, PD patient-specific induced pluripotent stem cells were differentiated into cardiomyocytes (PD-iCMs) that exhibited cardiomyopathic features of PD, including decreased acid alpha-glucosidase activity, lysosomal glycogen accumulation and hypertrophy. The defective mitochondria were involved in the cardiac pathology as shown by the significantly decreased number of mitochondria and impaired respiratory function and ATP production in PD-iCMs, which was partially due to elevated levels of intracellular reactive oxygen species produced from depolarized mitochondria. Further analysis showed that impaired fusion and autophagy of mitochondria and declined expression of mitochondrial complexes underlies the mechanism of dysfunctional mitochondria. This was alleviated by supplementation with recombinant human acid alpha-glucosidase that improved the mitochondrial function and concomitantly mitigated the cardiac pathology. Therefore, this study suggests that defective mitochondria underlie the pathogenesis of cardiomyopathy in patients with PD.
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Cardiomiopatia Hipertrófica , Doença de Depósito de Glicogênio Tipo II , Células-Tronco Pluripotentes Induzidas , Doenças Mitocondriais , Humanos , Doença de Depósito de Glicogênio Tipo II/metabolismo , Doença de Depósito de Glicogênio Tipo II/patologia , Miócitos Cardíacos/metabolismo , Células-Tronco Pluripotentes Induzidas/metabolismo , Cardiomiopatia Hipertrófica/metabolismo , Cardiomiopatia Hipertrófica/patologia , Doenças Mitocondriais/metabolismo , Doenças Mitocondriais/patologiaRESUMO
Background and Objectives: Gene expression, morphology, and electrophysiological combination are essential for assessing the dynamic development of human induced pluripotent stem cell-derived atrial- and ventricular-like cardiomyocytes (iPS-AM and iPS-VM, respectively). Methods: For iPS-AM/VM differentiation, we performed the small molecule-based temporal modulation of the retinoic acid and bone morphogenetic protein signaling pathways. We investigated the gene expression and morphology using immunofluorescence, quantitative real-time polymerase chain reaction, flow cytometry, and transmission electron microscopy as well as registered electrophysiological functions using a whole-cell patch clamp on days 20, 30, and 60 post-differentiations. Results: Pan-cardiomyocyte marker, including troponin T2 (TNNT2) and alpha-actinin-2 (ACTN2), expressions increased both in iPS-AMs and iPS-VMs. Similarly, the mRNA expression of both iPS-AM-specific markers, ie, natriuretic peptide A (NPPA), myosin light chain 7 (MYL7), and K+ channel Kir3.4 (KCNJ5), and iPS-VM-specific markers, ie, gap junction α-1 (GJA1), myosin light chain 2 (MYL2), and alpha-1-subunit of a voltage-dependent L-type calcium channel (CACNA1C), increased from 0 to 20 days, and then decreased from 30 to 60 days. Concerning morphology, cardiac troponin-T (cTnT) arrangement was progressively organized and developed from a disorderly myofibrillar distribution to an organized sarcomere pattern both in iPS-AMs and iPS-VMs. Mitochondrial numbers gradually increased and those of lipid droplets decreased during dynamic development. Regarding physiological function, the resting and action potential amplitudes remained statistically indifferent in both cell types, and the action potential duration was prolonged during the development. Conclusion: IPS-AMs/VMs displayed dynamic development concerning their gene expression, morphology, and electrophysiological function. The discoveries of this study could provide novel insights into heart development and encourage further research.
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OBJECTIVE: This study aimed to analyze the risk factors for recurrent ischemic stroke in patients with symptomatic intracranial atherosclerotic stenosis (ICAS) who underwent successful stent placement and to establish a nomogram prediction model. METHODS: We utilized data from a prospective collection of 430 consecutive patients at Jining NO.1 People's Hospital from November 2021 to November 2022, conducting further analysis on the subset of 400 patients who met the inclusion criteria. They were further divided into training (n=321) and validation (n=79) groups. In the training group, we used univariate and multivariate COX regression to find independent risk factors for recurrent stroke and then created a nomogram. The assessment of the nomogram's discrimination and calibration was performed through the examination of various measures including the Consistency index (C-index), the area under the receiver operating characteristic (ROC) curves (AUC), and the calibration plots. Decision curve analysis (DCA) was used to evaluate the clinical utility of the nomogram by quantifying the net benefit to the patient under different threshold probabilities. RESULTS: The nomogram for predicting recurrent ischemic stroke in symptomatic ICAS patients after stent placement utilizes six variables: coronary heart disease (CHD), smoking, multiple ICAS, systolic blood pressure (SBP), in-stent restenosis (ISR), and fasting plasma glucose. The C-index (0.884 for the training cohort and 0.87 for the validation cohort) and the time-dependent AUC (>0.7) indicated satisfactory discriminative ability of the nomogram. Furthermore, DCA indicated a clinical net benefit from the nomogram. CONCLUSIONS: The predictive model constructed includes six predictive factors: CHD, smoking, multiple ICAS, SBP, ISR and fasting blood glucose. The model demonstrates good predictive ability and can be utilized to predict ischemic stroke recurrence in patients with symptomatic ICAS after successful stent placement.
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Arteriosclerose Intracraniana , AVC Isquêmico , Nomogramas , Recidiva , Stents , Humanos , Masculino , Feminino , Arteriosclerose Intracraniana/cirurgia , Arteriosclerose Intracraniana/diagnóstico por imagem , Pessoa de Meia-Idade , AVC Isquêmico/cirurgia , AVC Isquêmico/etiologia , Idoso , Fatores de Risco , Estudos Prospectivos , Constrição Patológica/cirurgiaRESUMO
Li-Campeau syndrome (LICAS) is a syndromic neurodevelopmental disorder characterized by autosomal recessive inheritance and global developmental delay. In this study, we reported the generation of a novel induced pluripotent stem cell (iPSC) line derived from peripheral blood mononuclear cells (PBMCs) obtained from a 7-year-old male patient with Li-Campeau syndrome. The patient carries compound heterozygous variants in the UBR7 gene (c.35_54dup, p.S19Rfs*42; c.863 T > C, p.L288P). The iPSC line showed typical cell morphology, robust expression of pluripotent and self-renewal markers, normal karyotype, and trilineage differentiation potential. This iPSC cell line could be valuable for investigating the underlying pathological mechanisms of neurodevelopmental disorders caused by UBR7 mutations.
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Células-Tronco Pluripotentes Induzidas , Masculino , Humanos , Criança , Células-Tronco Pluripotentes Induzidas/metabolismo , Linhagem Celular , Leucócitos Mononucleares , Mutação/genética , Diferenciação Celular/genéticaRESUMO
Introduction: Many endocrine diseases, such as neuroblastoma (NB), can be linked with acquired cardiomyopathy and heart failure. Neuroblastoma's cardiovascular manifestations are typically hypertension, electrocardiogram (ECG) changes, and conduction disturbances. Case Presentation: A 5-year-old 8-month-old girl was admitted to the hospital with ventricular hypertrophy and hypertension (HT) and heart failure. She had no previous history of HT. On color doppler echocardiography, the left atrium and left ventricle were enlarged. The left ventricular ejection fraction (EF) was as low as 40%, and the ventricular septum and left ventricular free wall were thickened. The internal diameters of both coronary arteries were widened. Abdominal computed tomography scan (CT) demonstrated an 8.7â cm × 7.1â cm × 9.5â cm tumor behind the left peritoneum. In urine catecholamines analysis, free-norepinephrine (f-NE), free-dopamine (f-DA), free-normetanephrine (f-NMN), free-3-methoxytyramine (f-3MT), vanillylmandelic acid (VMA), and homovanillic acid (HVA) levels were all greater than the normal range for 24â h except free-metanephrine (f-MN) and free-epinephrine (f-E). Based on these findings, we diagnosed her as NB complicated by catecholamine cardiomyopathy manifested by hypertrophic cardiomyopathy (HCM). Oral metoprolol, spironolactone, captopril and amlodipine furosemide, and intravenously injected sodium nitroprusside and phentolamine were employed for treating HT. After the tumor resection, the blood pressure (BP) and urinary catecholamine levels were all restored. After a follow-up of 7 months, echocardiography indicated normalization of ventricular hypertrophy and function. Conclusion: This is a rare report showing catecholamine cardiomyopathy in NB children. Tumor resection leads to a return to normal of the catecholamine cardiomyopathy manifested as HCM.
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BACKGROUND: Acute large vessel occlusion due to underlying intracranial atherosclerotic stenosis (ICAS-LVO) increases the difficulty of revascularization, resulting in frequent re-occlusion. The establishment of its pathogenesis before endovascular treatment (EVT) is beneficial for patients. We aimed at developing and validating a clinical prediction model for ICAS-LVO patients before EVT. METHODS: Patients with acute large vessel occlusion at Jining No. 1 People's Hospital from January 2019 to September 2021 were retrospectively included as the training cohort. The 70 patients who met the inclusion and exclusion criteria were included in the validation cohort (October 2021 to May 2022). Demographics, onset form, medical history, digital subtraction angiography (DSA) imaging data, and laboratory test data were collected. Preprocedural parameters for the ICAS-LVO risk prediction model were established by stepwise logistic regression controlling for the confounding effects. Then, we constructed a nomogram model and evaluated its performance via the Hosmer-Lemeshow goodness-of-fit test, area under the ROC curve (AUC) analysis. RESULTS: The 231 acute LVO patients were included in the final analysis, 74 (32.3%) patients were ICAS-LVO. A preoperative diagnosis prediction model consisting of five predictors for ICAS-LVO, including fluctuating symptoms, NIHSS <â¯16, atrial fibrillation, tapered sign, and ASITN/SIR score ≥â¯2. The model depicted an acceptable calibration (Hosmer-Lemeshow test, pâ¯= 0.451) and good discrimination (AUC, 0.941; 95% confidence interval, 0.910-0.971). The optimal cut-off value for the ICAS-LVO scale was 2 points, with 86.5% sensitivity, 91.1% specificity, and 90.5% accuracy. In the validation cohort, the discriminative ability was promising with an AUC value of 0.897, implying a good predictive performance. CONCLUSION: The established ICAS-LVO scale, which is composed of five predictors: fluctuating symptoms, NIHSS <â¯16, atrial fibrillation, tapered sign, and ASITN/SIR score ≥â¯2, has a good predictive value for ICAS-LVO in Chinese populations.
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Fibrilação Atrial , Arteriosclerose Intracraniana , Acidente Vascular Cerebral , Humanos , Estudos Retrospectivos , Constrição Patológica , Fibrilação Atrial/diagnóstico , Modelos Estatísticos , Prognóstico , Arteriosclerose Intracraniana/complicações , Arteriosclerose Intracraniana/diagnóstico por imagem , Acidente Vascular Cerebral/terapiaRESUMO
We illustrate use of induced pluripotent stem cells (iPSCs) as platforms for investigating cardiomyocyte phenotypes in a human family pedigree exemplified by novel heterozygous RYR2-A1855D and SCN10A-Q1362H variants occurring alone and in combination. The proband, a four-month-old boy, presented with polymorphic ventricular tachycardia. Genetic tests revealed double novel heterozygous RYR2-A1855D and SCN10A-Q1362H variants inherited from his father (F) and mother (M), respectively. His father showed ventricular premature beats; his mother was asymptomatic. Molecular biological characterizations demonstrated greater TNNT2 messenger RNA (mRNA) expression in the iPSCs-induced cardiomyocytes (iPS-CMs) than in the iPSCs. Cardiac troponin Ts became progressively organized but cytoplasmic RYR2 and SCN10A aggregations occurred in the iPS-CMs. Proband-specific iPS-CMs showed decreased RYR2 and SCN10A mRNA expression. The RYR2-A1855D variant resulted in premature spontaneous sarcoplasmic reticular Ca2+ transients, Ca2+ oscillations and increased action potential durations. SCN10A-Q1362H did not confer any specific phenotype. However, the combined heterozygous RYR2-A1855D and SCN10A-Q1362H variants in the proband iPS-CMs resulted in accentuated Ca2+ homeostasis disorders, action potential prolongation and susceptibility to early afterdepolarizations at high stimulus frequencies. These findings attribute the clinical phenotype in the proband to effects of the heterozygous RYR2 variant exacerbated by heterozygous SCN10A modification. This article is part of the theme issue 'The heartbeat: its molecular basis and physiological mechanisms'.
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Células-Tronco Pluripotentes Induzidas , Taquicardia Ventricular , Humanos , Lactente , Masculino , Arritmias Cardíacas/genética , Arritmias Cardíacas/metabolismo , Cálcio/metabolismo , Homeostase , Mutação , Canal de Sódio Disparado por Voltagem NAV1.8/genética , Canal de Sódio Disparado por Voltagem NAV1.8/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/farmacologia , Taquicardia Ventricular/genética , Taquicardia Ventricular/metabolismoRESUMO
P21-activated kinase 1 (Pak1) signalling plays a vital and overall protective role in the heart. However, the phenotypes of Pak1 deficiency in the cardiac atria have not been well explored. In this study, Pak1 cardiac-conditional knock-out (cKO) mice were studied under baseline and adrenergic challenge conditions. Pak1 cKO mice show atrial arrhythmias including atrial fibrillation (AF) in vivo, detected during anaesthetized electrocardiography without evidence of interstitial fibrosis upon Masson's trichrome staining. Optical mapping of left atrial preparations from Pak1 cKO mice revealed a higher incidence of Ca2+ and action potential alternans under isoprenaline challenge and differences in baseline action potential and calcium transient characteristics. Type-2 ryanodine receptor (RyR2) channels from Pak1 cKO hearts had a higher open probability than those from wild-type. Reverse transcription-quantitative polymerase chain reaction and Western blotting indicated that pCamkIIδ and RyR2 are highly phosphorylated at baseline in the atria of Pak1 cKO mice, while the expression of Slc8a2 and Slc8a3 as a Na+-Ca2+ exchanger, controlling the influx of Ca2+ from outside of the cell and efflux of Na+ from the cytoplasm, are augmented. Chromatin immunoprecipitation study showed that pCreb1 interacts with Slc8a2 and Slc8a3. Our study thus demonstrates that deficiency of Pak1 promotes atrial arrhythmogenesis under adrenergic stress, probably through post-translational and transcriptional modifications of key molecules that are critical to Ca2+ homeostasis. This article is part of the theme issue 'The heartbeat: its molecular basis and physiological mechanisms'.
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Fibrilação Atrial , Camundongos , Animais , Fibrilação Atrial/genética , Fibrilação Atrial/metabolismo , Miócitos Cardíacos/metabolismo , Adrenérgicos/metabolismo , Quinases Ativadas por p21/genética , Quinases Ativadas por p21/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Camundongos Knockout , Cálcio/metabolismo , Trocador de Sódio e Cálcio/metabolismoRESUMO
Ca2+-activated K+ channels are critical to cellular Ca2+ homeostasis and excitability; they couple intracellular Ca2+ and membrane voltage change. Of these, the small, 4-14 pS, conductance SK channels include three, KCNN1-3 encoded, SK1/KCa2.1, SK2/KCa2.2 and SK3/KCa2.3, channel subtypes with characteristic, EC50 â¼ 10 nM, 40 pM, 1 nM, apamin sensitivities. All SK channels, particularly SK2 channels, are expressed in atrial, ventricular and conducting system cardiomyocytes. Pharmacological and genetic modification results have suggested that SK channel block or knockout prolonged action potential durations (APDs) and effective refractory periods (ERPs) particularly in atrial, but also in ventricular, and sinoatrial, atrioventricular node and Purkinje myocytes, correspondingly affect arrhythmic tendency. Additionally, mitochondrial SK channels may decrease mitochondrial Ca2+ overload and reactive oxygen species generation. SK channels show low voltage but marked Ca2+ dependences (EC50 â¼ 300-500 nM) reflecting their α-subunit calmodulin (CaM) binding domains, through which they may be activated by voltage-gated or ryanodine-receptor Ca2+ channel activity. SK function also depends upon complex trafficking and expression processes and associations with other ion channels or subunits from different SK subtypes. Atrial and ventricular clinical arrhythmogenesis may follow both increased or decreased SK expression through decreased or increased APD correspondingly accelerating and stabilizing re-entrant rotors or increasing incidences of triggered activity. This article is part of the theme issue 'The heartbeat: its molecular basis and physiological mechanisms'.
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Fibrilação Atrial , Canais de Potássio Ativados por Cálcio de Condutância Baixa , Humanos , Canais de Potássio Ativados por Cálcio de Condutância Baixa/genética , Canais de Potássio Ativados por Cálcio de Condutância Baixa/metabolismo , Fibrilação Atrial/metabolismo , Átrios do Coração/metabolismo , Potenciais de Ação/fisiologia , Miócitos Cardíacos/metabolismoRESUMO
Atrial fibrillation (AF) is the most common chronic arrhythmia presenting a heavy disease burden. We report a new approach for generating cardiomyocytes (CMs) resembling atrial cells from human-induced pluripotent stem cells (hiPSCs) using a combination of Gremlin 2 and retinoic acid treatment. More than 40% of myocytes showed rod-shaped morphology, expression of CM proteins (including ryanodine receptor 2, α-actinin-2 and F-actin) and striated appearance, all of which were broadly similar to the characteristics of adult atrial myocytes (AMs). Isolated myocytes were electrically quiescent until stimulated to fire action potentials with an AM profile and an amplitude of approximately 100 mV, arising from a resting potential of approximately -70 mV. Single-cell RNA sequence analysis showed a high level of expression of several atrial-specific transcripts including NPPA, MYL7, HOXA3, SLN, KCNJ4, KCNJ5 and KCNA5. Amplitudes of calcium transients recorded from spontaneously beating cultures were increased by the stimulation of α-adrenoceptors (activated by phenylephrine and blocked by prazosin) or ß-adrenoceptors (activated by isoproterenol and blocked by CGP20712A). Our new approach provides human AMs with mature characteristics from hiPSCs which will facilitate drug discovery by enabling the study of human atrial cell signalling pathways and AF. This article is part of the theme issue 'The heartbeat: its molecular basis and physiological mechanisms'.
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Fibrilação Atrial , Células-Tronco Pluripotentes Induzidas , Adulto , Humanos , Miócitos Cardíacos/metabolismo , Diferenciação Celular/fisiologia , Fibrilação Atrial/metabolismo , Receptores Adrenérgicos/metabolismo , Canais de Potássio Corretores do Fluxo de Internalização Acoplados a Proteínas G/metabolismoRESUMO
RATIONALE: Desorption electrospray ionization (DESI) is the most popular ambient ionization technique for direct analysis of complex samples without sample pretreatment. However, for many applications, especially for trace analysis, it is of interest to improve the sensitivity of DESI-mass spectrometry (MS). METHODS: In traditional DESI-MS, a mixture of methanol/water/acetic acid is usually used to generate the primary ions. In this article, dilute protein solutions were electrosprayed in the DESI method to create multiply charged primary ions for the desorption ionization of trace analytes on various surfaces (e.g., filter paper, glass, Al-foil) without any sample pretreatment. The analyte ions were then detected and structurally characterized using a LTQ XL mass spectrometer. RESULTS: Compared with the methanol/water/acetic acid (49:49:2, v/v/v) solution, protein solutions significantly increased the signal levels of non-volatile compounds such as benzoic acid, TNT, o-toluidine, peptide and insulin in either positive or negative ion detection mode. For all the analytes tested, the limits of detection (LODs) were reduced to about half of the original values which were obtained using traditional DESI. The results showed that the signal enhancement is highly correlated with the molecular weight of the proteins and the selected solid surfaces. CONCLUSIONS: The proposed DESI method is a universal strategy for rapid and sensitive detection of trace amounts of strongly bound and/or non-volatile analytes, including explosives, peptides, and proteins. The results indicate that the sensitivity of DESI can be further improved by selecting larger proteins and appropriate solid surfaces.
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Espectrometria de Massas por Ionização por Electrospray/métodos , Animais , Ácido Benzoico/análise , Substâncias Explosivas/análise , Humanos , Insulina/análise , Íons/química , Limite de Detecção , Peptídeos/análise , Proteínas/química , Soluções/química , Toluidinas/análise , Trinitrotolueno/análiseRESUMO
With the rapid development of industry in China, the number of establishments that are proposed or under construction is increasing year by year, and many are industries that handle flammable, explosive, toxic, harmful, and dangerous substances. Accidents such as fire, explosion, and toxic diffusion inevitably happen. Accidents resulting from these major hazards in cities cause a large number of casualties and property losses. It is increasingly important to analyze the risk of major hazards in cities realistically and to suitably plan and utilize the surrounding land based on the risk analysis results, thereby reducing the hazards. A theoretical system for risk assessment of major hazards in cities is proposed in this article, and the major hazard risk for the entire city is analyzed quantitatively. Risks of various major accidents are considered together, superposition effect is analyzed, individual risk contours of the entire city are drawn out, and the level of risk in the city is assessed using "as low as reasonably practicable" guidelines. After the entire city's individual risk distribution is obtained, risk zones are divided according to corresponding individual risk value of HSE, and land-use planning suggestions are proposed. Finally, a city in China is used as an example to illustrate the risk assessment process of the city's major hazard and its application in urban land-use planning. The proposed method has a certain theoretical and practical significance in establishing and improving risk analysis of major hazard and urban land-use planning. On the one hand, major urban public risk is avoided; further, the land is utilized in the best possible way in order to obtain the maximum benefit from its use.
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Planejamento de Cidades , Medição de Risco , Acidentes/mortalidade , Acidentes/estatística & dados numéricos , Acidentes de Trabalho/prevenção & controle , Acidentes de Trabalho/estatística & dados numéricos , China/epidemiologia , Substâncias Perigosas/toxicidade , Humanos , Fatores de RiscoRESUMO
As the most frequently diagnosed arrhythmia, atrial fibrillation (AF) has been recently reported to be closely related to ryanodine receptor (RyR2) dysfunction and calcium leak. Here, using non-integrating sendai viral method, we generated one iPSC line from peripheral blood mononuclear cells (PBMC) isolated a 10-year-old boy with simple atrial fibrillation which carries the heterozygous mutation in RYR2 gene (c.14638G > A, p.V4880I). The generated iPSC line was identified by the typical cell morphology, highly expressed pluripotent markers, normal karyotype, and in-vitro trilineage differentiation potential. It will provide a useful model for studying the pathophysiological consequences of RYR2 mutation on the AF pathogenesis.
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Fibrilação Atrial , Células-Tronco Pluripotentes Induzidas , Humanos , Criança , Fibrilação Atrial/genética , Leucócitos Mononucleares , Mutação/genéticaRESUMO
Pompe disease results from GAA mutations that leads to lysosomal glycogen accumulation and cardiac and skeletal muscle pathology. We have previously generated an infantile-onset Pompe disease patient-derived human-induced pluripotent stem cells (iPSCs) line carrying compound GAA mutations (R608X and E888X). Using his parents' peripheral blood mononuclear cells (PBMCs), we here generated two iPSCs lines which carry mutations of R608X E888X respectively. Both lines show typical cell morphology, high expressed pluripotent and self-renewal markers, normal karyotype, and trilineage differentiation potential. These two lines are valuable re-sources for studying the pathological mechanisms of GAA mutation-caused Pompe disease.