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1.
Virol J ; 21(1): 2, 2024 01 03.
Artigo em Inglês | MEDLINE | ID: mdl-38172898

RESUMO

Only few studies have investigated the prevalence of feline coronavirus (FCoV) infection in domestic cats in Fujian, China. This is the first study to report the prevalence rate of FCoV infection in domestic cats in Fujian, China, and to analyse the epidemiological characteristics of FCoV infection in the region. A total of 112 cat faecal samples were collected from animal hospitals and catteries in the Fujian Province. RNA was extracted from faecal material for reverse transcription polymerase chain reaction (RT-PCR). The prevalence rate of FCoV infection was determined, and its epidemiological risk factors were analysed. The overall prevalence of FCoV infection in the cats, was 67.9%. We did not observe a significant association between the age, sex, or breed of the cats included in the study and the prevalence rate of the viral infection. Phylogenetic analysis showed that the four strains from Fujian were all type I FCoV. This is the first study to analyse the prevalence and epidemiological characteristics of FCoV infection in domestic cats in Fujian, China, using faecal samples. The results of this study provide preliminary data regarding the prevalence of FCoV infection in the Fujian Province for epidemiological studies on FCoV in China and worldwide. Future studies should perform systematic and comprehensive epidemiological investigations to determine the prevalence of FCoV infection in the region.


Assuntos
Infecções por Coronavirus , Coronavirus Felino , Peritonite Infecciosa Felina , Gatos , Animais , Peritonite Infecciosa Felina/epidemiologia , Peritonite Infecciosa Felina/genética , Prevalência , Filogenia , RNA Viral/genética , RNA Viral/análise , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/veterinária , Coronavirus Felino/genética , China/epidemiologia
2.
Artigo em Inglês | MEDLINE | ID: mdl-38587654

RESUMO

PURPOSE: This study is to evaluate the correlation between retrobulbar perfusion deficits and glaucomatous visual field defects. METHODS: Eighty-four patients with glaucoma and 17 normal subjects serving as controls were selected. Color Doppler imaging (CDI) was used to measure the changes in blood flow parameters in the retrobulbar ophthalmic artery (OA), central retinal artery (CRA), and short posterior ciliary arteries (SPCAs). Visual field testing was performed using a Humphrey perimeter, categorizing the visual field deficits into four stages according to the Advanced Glaucoma Intervention Study (AGIS) scoring method. Subsequently, the correlation of retrobulbar hemodynamic parameter alterations among glaucomatous patients with varying visual field defects was examined. RESULTS: The higher the visual field stage, the lower the peak systolic velocity (PSV) of the OA, CRA, and SPCAs in glaucomatous patients. The CRA had the highest sensitivity to changes in its PSV. The PSV of the temporal SPCA (TSPCA-PSV) was lower in advanced glaucoma than in early-stage glaucoma. The PSVs of the OA, CRA, and TSPCA, as well as the resistance index of the CRA (CRA-RI), were positively correlated with the visual field index and the mean deviation. Except for that of OA, the PSV of the retrobulbar vessels was negatively correlated with the pattern standard deviation (PSD). The OA-PSV and end-diastolic velocity (EDV) of the CRA and TSPCA were lower in patients with superior visual field defects than in those with inferior visual field defects. CONCLUSIONS: Greater severity of visual field defects corresponded to poorer retrobulbar blood flow in glaucomatous patients. Patients suffered significant perfusion impairments in the CRA at the early stage, accompanied by SPCA perfusion disorder at the advanced stage. The presence of a bow-shaped defect in the superior or inferior region of the visual field in moderate-stage glaucoma was closely correlated with retrobulbar vascular EDV. TRIAL REGISTRATION: ChiCTR2200059048 (2022-04-23).

3.
Biochem J ; 480(17): 1379-1395, 2023 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-37492947

RESUMO

Gain-of-function missense variants in the cardiac ryanodine receptor (RyR2) are linked to catecholaminergic polymorphic ventricular tachycardia (CPVT), whereas RyR2 loss-of-function missense variants cause Ca2+ release deficiency syndrome (CRDS). Recently, truncating variants in RyR2 have also been associated with ventricular arrhythmias (VAs) and sudden cardiac death. However, there are limited insights into the potential clinical relevance and in vitro functional impact of RyR2 truncating variants. We performed genetic screening of patients presenting with syncope, VAs, or unexplained sudden death and in vitro characterization of the expression and function of RyR2 truncating variants in HEK293 cells. We identified two previously unknown RyR2 truncating variants (Y4591Ter and R4663Ter) and one splice site variant predicted to result in a frameshift and premature termination (N4717 + 15Ter). These 3 new RyR2 truncating variants and a recently reported RyR2 truncating variant, R4790Ter, were generated and functionally characterized in vitro. Immunoprecipitation and immunoblotting analyses showed that all 4 RyR2 truncating variants formed heteromers with the RyR2-wildtype (WT) protein. Each of these C-terminal RyR2 truncations was non-functional and suppressed [3H]ryanodine binding to RyR2-WT and RyR2-WT mediated store overload induced spontaneous Ca2+ release activity in HEK293 cells. The expression of these RyR2 truncating variants in HEK293 cells was markedly reduced compared with that of the full-length RyR2 WT protein. Our data indicate that C-terminal RyR2 truncating variants are non-functional and can exert a dominant negative impact on the function of the RyR2 WT protein through formation of heteromeric WT/truncation complex.


Assuntos
Canal de Liberação de Cálcio do Receptor de Rianodina , Taquicardia Ventricular , Humanos , Arritmias Cardíacas/genética , Cálcio/metabolismo , Células HEK293 , Mutação , Fenótipo , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Taquicardia Ventricular/genética , Taquicardia Ventricular/metabolismo
4.
Circ Res ; 128(4): e63-e83, 2021 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-33375811

RESUMO

RATIONALE: Ca2+ alternans plays an essential role in cardiac alternans that can lead to ventricular fibrillation, but the mechanism underlying Ca2+ alternans remains undefined. Increasing evidence suggests that Ca2+ alternans results from alternations in the inactivation of cardiac RyR2 (ryanodine receptor 2). However, what inactivates RyR2 and how RyR2 inactivation leads to Ca2+ alternans are unknown. OBJECTIVE: To determine the role of CaM (calmodulin) on Ca2+ alternans in intact working mouse hearts. METHODS AND RESULTS: We used an in vivo local gene delivery approach to alter CaM function by directly injecting adenoviruses expressing CaM-wild type, a loss-of-function CaM mutation, CaM (1-4), and a gain-of-function mutation, CaM-M37Q, into the anterior wall of the left ventricle of RyR2 wild type or mutant mouse hearts. We monitored Ca2+ transients in ventricular myocytes near the adenovirus-injection sites in Langendorff-perfused intact working hearts using confocal Ca2+ imaging. We found that CaM-wild type and CaM-M37Q promoted Ca2+ alternans and prolonged Ca2+ transient recovery in intact RyR2 wild type and mutant hearts, whereas CaM (1-4) exerted opposite effects. Altered CaM function also affected the recovery from inactivation of the L-type Ca2+ current but had no significant impact on sarcoplasmic reticulum Ca2+ content. Furthermore, we developed a novel numerical myocyte model of Ca2+ alternans that incorporates Ca2+-CaM-dependent regulation of RyR2 and the L-type Ca2+ channel. Remarkably, the new model recapitulates the impact on Ca2+ alternans of altered CaM and RyR2 functions under 9 different experimental conditions. Our simulations reveal that diastolic cytosolic Ca2+ elevation as a result of rapid pacing triggers Ca2+-CaM dependent inactivation of RyR2. The resultant RyR2 inactivation diminishes sarcoplasmic reticulum Ca2+ release, which, in turn, reduces diastolic cytosolic Ca2+, leading to alternations in diastolic cytosolic Ca2+, RyR2 inactivation, and sarcoplasmic reticulum Ca2+ release (ie, Ca2+ alternans). CONCLUSIONS: Our results demonstrate that inactivation of RyR2 by Ca2+-CaM is a major determinant of Ca2+ alternans, making Ca2+-CaM dependent regulation of RyR2 an important therapeutic target for cardiac alternans.


Assuntos
Sinalização do Cálcio , Coração/fisiologia , Miócitos Cardíacos/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Potenciais de Ação , Animais , Canais de Cálcio Tipo L/metabolismo , Calmodulina/metabolismo , Células Cultivadas , Frequência Cardíaca , Camundongos , Camundongos Endogâmicos C57BL , Contração Miocárdica , Miócitos Cardíacos/fisiologia
5.
J Biol Chem ; 293(35): 13650-13661, 2018 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-29986885

RESUMO

Sarcoplasmic reticulum (SR) Ca2+ cycling is governed by the cardiac ryanodine receptor (RyR2) and SR Ca2+-ATPase (SERCA2a). Abnormal SR Ca2+ cycling is thought to be the primary cause of Ca2+ alternans that can elicit ventricular arrhythmias and sudden cardiac arrest. Although alterations in either RyR2 or SERCA2a function are expected to affect SR Ca2+ cycling, whether and to what extent altered RyR2 or SERCA2a function affects Ca2+ alternans is unclear. Here, we employed a gain-of-function RyR2 variant (R4496C) and the phospholamban-knockout (PLB-KO) mouse model to assess the effect of genetically enhanced RyR2 or SERCA2a function on Ca2+ alternans. Confocal Ca2+ imaging revealed that RyR2-R4496C shortened SR Ca2+ release refractoriness and markedly suppressed rapid pacing-induced Ca2+ alternans. Interestingly, despite enhancing RyR2 function, intact RyR2-R4496C hearts exhibited no detectable spontaneous SR Ca2+ release events during pacing. Unlike for RyR2, enhancing SERCA2a function by ablating PLB exerted a relatively minor effect on Ca2+ alternans in intact hearts expressing RyR2 WT or a loss-of-function RyR2 variant, E4872Q, that promotes Ca2+ alternans. Furthermore, partial SERCA2a inhibition with 3 µm 2,5-di-tert-butylhydroquinone (tBHQ) also had little impact on Ca2+ alternans, whereas strong SERCA2a inhibition with 10 µm tBHQ markedly reduced the amplitude of Ca2+ transients and suppressed Ca2+ alternans in intact hearts. Our results demonstrate that enhanced RyR2 function suppresses Ca2+ alternans in the absence of spontaneous Ca2+ release and that RyR2, but not SERCA2a, is a key determinant of Ca2+ alternans in intact working hearts, making RyR2 an important therapeutic target for cardiac alternans.


Assuntos
Cálcio/metabolismo , Miocárdio/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Animais , Sinalização do Cálcio , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Camundongos , Camundongos Knockout , Mutação Puntual , Canal de Liberação de Cálcio do Receptor de Rianodina/genética
6.
Biochem J ; 475(1): 169-183, 2018 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-29170159

RESUMO

Reduced protein expression of the cardiac ryanodine receptor type 2 (RyR2) is thought to affect the susceptibility to stress-induced ventricular tachyarrhythmia (VT) and cardiac alternans, but direct evidence for the role of RyR2 protein expression in VT and cardiac alternans is lacking. Here, we used a mouse model (crrm1) that expresses a reduced level of the RyR2 protein to determine the impact of reduced RyR2 protein expression on the susceptibility to VT, cardiac alternans, cardiac hypertrophy, and sudden death. Electrocardiographic analysis revealed that after the injection of relatively high doses of caffeine and epinephrine (agents commonly used for stress test), wild-type (WT) mice displayed long-lasting VTs, whereas the crrm1 mutant mice exhibited no VTs at all, indicating that the crrm1 mutant mice are resistant to stress-induced VTs. Intact heart Ca2+ imaging and action potential (AP) recordings showed that the crrm1 mutant mice are more susceptible to fast-pacing induced Ca2+ alternans and AP duration alternans compared with WT mice. The crrm1 mutant mice also showed an increased heart-to-body-weight ratio and incidence of sudden death at young ages. Furthermore, the crrm1 mutant hearts displayed altered Ca2+ transients with increased time-to-peak and decay time (T50), increased ventricular wall thickness and ventricular cell area compared with WT hearts. These results indicate that reduced RyR2 protein expression suppresses stress-induced VTs, but enhances the susceptibility to cardiac alternans, hypertrophy, and sudden death.


Assuntos
Cálcio/metabolismo , Cardiomegalia/genética , Ventrículos do Coração/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Taquicardia Ventricular/genética , Potenciais de Ação/efeitos dos fármacos , Animais , Cafeína/farmacologia , Sinalização do Cálcio , Cardiomegalia/metabolismo , Cardiomegalia/fisiopatologia , Morte Súbita Cardíaca/patologia , Modelos Animais de Doenças , Epinefrina/farmacologia , Expressão Gênica , Ventrículos do Coração/efeitos dos fármacos , Ventrículos do Coração/patologia , Camundongos , Camundongos Transgênicos , Contração Muscular , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Técnicas de Cultura de Órgãos , Periodicidade , Canal de Liberação de Cálcio do Receptor de Rianodina/deficiência , Estresse Fisiológico/efeitos dos fármacos , Taquicardia Ventricular/metabolismo , Taquicardia Ventricular/fisiopatologia
7.
J Med Syst ; 43(3): 46, 2019 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-30661117

RESUMO

In order to improve medical quality, shorten hospital stays, and reduce redundant treatment, an optimization of diagnosis and treatment of chronic diseases based on association analysis under the background of regional integration in the paper was proposed, which was to expand the scope of application of the clinical pathway standard diagnosis and treatment program in the context of regional medical integration and mass medical data, so that it had a larger group of patients within the region. In the context of regional medical integration, owing to the types of medical data were diverse, the preprocessing requirements and process specifications for diagnosis and treatment data were firstly proposed. At the stage of diagnosis and treatment unit optimization, the correlation between clinical behaviors was analyzed by using association rules of the FP-growth and Apriori algorithm. Through the optimization and combination of diagnosis and treatment units, the optimized clinical pathway was finally achieved. Experiments showed that after the optimization strategy by the paper proposed, the clinical path diagnosis and treatment achieved obvious improvement in medical quality under the condition that the medical cost was basically flat.


Assuntos
Doença Crônica/terapia , Tomada de Decisão Clínica/métodos , Procedimentos Clínicos/estatística & dados numéricos , Registros Eletrônicos de Saúde/estatística & dados numéricos , Saúde da População/estatística & dados numéricos , Algoritmos , Big Data , Mineração de Dados/métodos , Eficiência Organizacional , Humanos , Melhoria de Qualidade
8.
Biochem J ; 473(21): 3951-3964, 2016 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-27582498

RESUMO

Beat-to-beat alternations in the amplitude of the cytosolic Ca2+ transient (Ca2+ alternans) are thought to be the primary cause of cardiac alternans that can lead to cardiac arrhythmias and sudden death. Despite its important role in arrhythmogenesis, the mechanism underlying Ca2+ alternans remains poorly understood. Here, we investigated the role of cardiac ryanodine receptor (RyR2), the major Ca2+ release channel responsible for cytosolic Ca2+ transients, in cardiac alternans. Using a unique mouse model harboring a suppression-of-function (SOF) RyR2 mutation (E4872Q), we assessed the effect of genetically suppressing RyR2 function on Ca2+ and action potential duration (APD) alternans in intact hearts, and electrocardiogram (ECG) alternans in vivo We found that RyR2-SOF hearts displayed prolonged sarcoplasmic reticulum Ca2+ release refractoriness and enhanced propensity for Ca2+ alternans. RyR2-SOF hearts/mice also exhibited increased propensity for APD and ECG alternans. Caffeine, which enhances RyR2 activity and the propensity for catecholaminergic polymorphic ventricular tachycardia (CPVT), suppressed Ca2+ alternans in RyR2-SOF hearts, whereas carvedilol, a ß-blocker that suppresses RyR2 activity and CPVT, promoted Ca2+ alternans in these hearts. Thus, RyR2 function is an important determinant of Ca2+, APD, and ECG alternans. Our data also indicate that the activity of RyR2 influences the propensity for cardiac alternans and CPVT in an opposite manner. Therefore, overly suppressing or enhancing RyR2 function is pro-arrhythmic.


Assuntos
Coração/fisiopatologia , Miocárdio/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Animais , Modelos Animais de Doenças , Eletrocardiografia , Coração/efeitos dos fármacos , Isoproterenol/farmacologia , Camundongos , Mutação/genética , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Retículo Sarcoplasmático/efeitos dos fármacos , Retículo Sarcoplasmático/metabolismo , Taquicardia/genética , Taquicardia/metabolismo , Taquicardia Ventricular/genética , Taquicardia Ventricular/metabolismo
9.
J Cell Sci ; 126(Pt 19): 4527-35, 2013 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-23868982

RESUMO

Calmodulin (CaM), a 16 kDa ubiquitous calcium-sensing protein, is known to bind tightly to the calcium release channel/ryanodine receptor (RyR), and modulate RyR function. CaM binding studies using RyR fragments or synthetic peptides have revealed the presence of multiple, potential CaM-binding regions in the primary sequence of RyR. In the present study, we inserted GFP into two of these proposed CaM-binding sequences and mapped them onto the three-dimensional structure of intact cardiac RyR2 by cryo-electron microscopy. Interestingly, we found that the two potential CaM-binding regions encompassing, Arg3595 and Lys4269, respectively, are in close proximity and are adjacent to the previously mapped CaM-binding sites. To monitor the conformational dynamics of these CaM-binding regions, we generated a fluorescence resonance energy transfer (FRET) pair, a dual CFP- and YFP-labeled RyR2 (RyR2R3595-CFP/K4269-YFP) with CFP inserted after Arg3595 and YFP inserted after Lys4269. We transfected HEK293 cells with the RyR2R3595-CFP/K4269-YFP cDNA, and examined their FRET signal in live cells. We detected significant FRET signals in transfected cells that are sensitive to the channel activator caffeine, suggesting that caffeine is able to induce conformational changes in these CaM-binding regions. Importantly, no significant FRET signals were detected in cells co-transfected with cDNAs encoding the single CFP (RyR2R3595-CFP) and single YFP (RyR2K4269-YFP) insertions, indicating that the FRET signal stemmed from the interaction between R3595-CFP and K4269-YFP that are in the same RyR subunit. These observations suggest that multiple regions in the RyR2 sequence may contribute to an intra-subunit CaM-binding pocket that undergoes conformational changes during channel gating.


Assuntos
Calmodulina/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Animais , Sítios de Ligação , Calmodulina/química , Humanos , Camundongos , Ligação Proteica , Subunidades Proteicas , Canal de Liberação de Cálcio do Receptor de Rianodina/química
10.
Circ Res ; 113(5): 517-26, 2013 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-23856523

RESUMO

RATIONALE: Phospholamban (PLN) is an inhibitor of cardiac sarco(endo)plasmic reticulum Ca²âº ATPase. PLN knockout (PLN-KO) enhances sarcoplasmic reticulum Ca²âº load and Ca²âº leak. Conversely, PLN-KO accelerates Ca²âº sequestration and aborts arrhythmogenic spontaneous Ca²âº waves (SCWs). An important question is whether these seemingly paradoxical effects of PLN-KO exacerbate or protect against Ca²âº-triggered arrhythmias. OBJECTIVE: We investigate the impact of PLN-KO on SCWs, triggered activities, and stress-induced ventricular tachyarrhythmias (VTs) in a mouse model of cardiac ryanodine-receptor (RyR2)-linked catecholaminergic polymorphic VT. METHODS AND RESULTS: We generated a PLN-deficient, RyR2-mutant mouse model (PLN-/-/RyR2-R4496C+/-) by crossbreeding PLN-KO mice with catecholaminergic polymorphic VT-associated RyR2-R4496C mutant mice. Ca²âº imaging and patch-clamp recording revealed cell-wide propagating SCWs and triggered activities in RyR2-R4496C+/- ventricular myocytes during sarcoplasmic reticulum Ca²âº overload. PLN-KO fragmented these cell-wide SCWs into mini-waves and Ca²âº sparks and suppressed the triggered activities evoked by sarcoplasmic reticulum Ca²âº overload. Importantly, these effects of PLN-KO were reverted by partially inhibiting sarco(endo)plasmic reticulum Ca²âº ATPase with 2,5-di-tert-butylhydroquinone. However, Bay K, caffeine, or Li⁺ failed to convert mini-waves to cell-wide SCWs in PLN-/-/RyR2-R4496C+/- ventricular myocytes. Furthermore, ECG analysis showed that PLN-KO mice are not susceptible to stress-induced VTs. On the contrary, PLN-KO protected RyR2-R4496C mutant mice from stress-induced VTs. CONCLUSIONS: Our results demonstrate that despite severe sarcoplasmic reticulum Ca²âº leak, PLN-KO suppresses triggered activities and stress-induced VTs in a mouse model of catecholaminergic polymorphic VT. These data suggest that breaking up cell-wide propagating SCWs by enhancing Ca²âº sequestration represents an effective approach for suppressing Ca²âº-triggered arrhythmias.


Assuntos
Sinalização do Cálcio/fisiologia , Proteínas de Ligação ao Cálcio/deficiência , Taquicardia Ventricular/prevenção & controle , Éster Metílico do Ácido 3-Piridinacarboxílico, 1,4-Di-Hidro-2,6-Dimetil-5-Nitro-4-(2-(Trifluormetil)fenil)/farmacologia , Animais , Cafeína/farmacologia , Sinalização do Cálcio/efeitos dos fármacos , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/fisiologia , ATPases Transportadoras de Cálcio/antagonistas & inibidores , Células Cultivadas/efeitos dos fármacos , Células Cultivadas/fisiologia , Modelos Animais de Doenças , Eletrocardiografia , Hidroquinonas/farmacologia , Isoproterenol/farmacologia , Cloreto de Lítio/farmacologia , Camundongos , Camundongos Knockout , Mutação de Sentido Incorreto , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/enzimologia , Miócitos Cardíacos/fisiologia , Técnicas de Patch-Clamp , Canal de Liberação de Cálcio do Receptor de Rianodina/deficiência , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Canal de Liberação de Cálcio do Receptor de Rianodina/fisiologia , Retículo Sarcoplasmático/enzimologia , Retículo Sarcoplasmático/fisiologia , Taquicardia Ventricular/diagnóstico por imagem , Taquicardia Ventricular/fisiopatologia , Ultrassonografia
11.
Biochem J ; 461(1): 99-106, 2014 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-24758151

RESUMO

CASQ2 (cardiac calsequestrin) is commonly believed to serve as the SR (sarcoplasmic reticulum) luminal Ca2+ sensor. Ablation of CASQ2 promotes SCWs (spontaneous Ca2+ waves) and CPVT (catecholaminergic polymorphic ventricular tachycardia) upon stress but not at rest. How SCWs and CPVT are triggered by stress in the absence of the CASQ2-based luminal Ca2+ sensor is an important unresolved question. In the present study, we assessed the role of the newly identified RyR2 (ryanodine receptor 2)-resident luminal Ca2+ sensor in determining SCW propensity, CPVT susceptibility and cardiac hypertrophy in Casq2-KO (knockout) mice. We crossbred Casq2-KO mice with RyR2 mutant (E4872Q+/-) mice, which lack RyR2-resident SR luminal Ca2+ sensing, to generate animals with both deficiencies. Casq2+/- and Casq2-/- mice showed stress-induced VTs (ventricular tachyarrhythmias), whereas Casq2+/-/E4872Q+/- and Casq2-/-/E4872Q+/- mice displayed little or no stress-induced VTs. Confocal Ca2+ imaging revealed that Casq2-/- hearts frequently exhibited SCWs after extracellular Ca2+ elevation or adrenergic stimulation, whereas Casq2-/-/E4872Q+/- hearts had few or no SCWs under the same conditions. Cardiac hypertrophy developed and CPVT susceptibility increased with age in Casq2-/- mice, but not in Casq2-/-/E4872Q+/- mice. However, the amplitudes and dynamics of voltage-induced Ca2+ transients in Casq2-/- and Casq2-/-/E4872Q+/- hearts were not significantly different. Our results indicate that SCWs, CPVT and hypertrophy in Casq2-null cardiac muscle are governed by the RyR2-resident luminal Ca2+ sensor. This implies that defects in CASQ2-based lumi-nal Ca2+ sensing can be overridden by the RyR2-resident luminal Ca2+ sensor. This makes this RyR2-resident sensor a promising molecular target for the treatment of Ca2+-mediated arrhythmias.


Assuntos
Sinalização do Cálcio/fisiologia , Cálcio/metabolismo , Calsequestrina/deficiência , Cardiomegalia/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/fisiologia , Taquicardia Ventricular/metabolismo , Animais , Calsequestrina/genética , Cardiomegalia/genética , Cardiomegalia/fisiopatologia , Camundongos , Camundongos Knockout , Mutação/genética , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Taquicardia Ventricular/genética , Taquicardia Ventricular/fisiopatologia
12.
J Biol Chem ; 288(2): 903-14, 2013 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-23204524

RESUMO

Ryanodine receptors (RyRs) form a class of intracellular calcium release channels in various excitable tissues and cells such as muscles and neurons. They are the major cellular mediators of the release of calcium ions from the sarcoplasmic reticulum, an essential step in muscle excitation-contraction coupling. Several crystal structures of skeletal muscle RyR1 peptide fragments have been solved, but these cover less than 15% of the full-length RyR1 sequence. In this study, by combining modeling techniques with sub-nanometer resolution cryo-electron microscopy (cryo-EM) maps, we obtained pseudo-atomic models for RyR fragments consisting of residues 850-1,056 in rabbit RyR1 or residues 861-1,067 in mouse RyR2. These fragments are docked into a domain that connects the central vestibule and corner clamp region of RyR, resulting in a good match of the secondary structure elements in the cryo-EM map and the pseudo-atomic models, which is also consistent with our previous mappings of GFP insertions by cryo-EM and with FRET measurements involving RyR and FK506-binding protein (FKBP). A combined model of the RyR fragment and FKBP docked into the cryo-EM map suggests that the fragment is positioned adjacent to the FKBP-binding site. Its predicted binding interface with FKBP consists primarily of electrostatic contacts and contains several disease-associated mutations. A dynamic interaction between the fragment and an RyR phosphorylation domain, characterized by FRET experiments, also supports the structural predictions of the pseudo-atomic models.


Assuntos
Canal de Liberação de Cálcio do Receptor de Rianodina/química , Sequência de Aminoácidos , Animais , Microscopia Crioeletrônica , Transferência Ressonante de Energia de Fluorescência , Proteínas de Fluorescência Verde/química , Camundongos , Modelos Moleculares , Simulação de Dinâmica Molecular , Dados de Sequência Molecular , Fosforilação , Conformação Proteica , Coelhos , Homologia de Sequência de Aminoácidos , Eletricidade Estática
13.
Parasit Vectors ; 17(1): 64, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38355686

RESUMO

BACKGROUND: Demodex blepharitis (DB) is a common disease of the ocular surface. The characteristics of the bacterial community in eyelash roots after Demodex infestation are still unknown. Knowledge of the characteristics of the bacterial community of eyelash follicles in patients with DB can provide valuable insights for guiding the diagnosis and treatment of DB. METHODS: Twenty-five patients with DB (DB group) and 21 non-DB volunteers (control group) were enrolled in the study. Eyelashes from the upper eyelid of the right eye were sampled, and 16S ribosomal DNA (rDNA) sequencing was performed to determine the V3-V4 regions of the microbial 16S rDNA gene within 1 month of infestation. The sequencing data of the two groups were analyzed and compared. The effect of the bacterium Burkholderia on the survival of Demodex mites was evaluated using Demodex obtained from 12 patients with DB other that the patients in the DB group. RESULTS: A total of 31 phyla and 862 genera were identified in the DB and control groups. The five most abundant phyla in the two groups were Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes and Cyanobacteria. The abundance of Actinomycetes was significantly higher in the DB group than in the control group. At the genus level, the five most abundant genera in the two groups were Pseudomonas, Burkholderia-Caballeronia-Paraburkholderia, Rolstonia and Acinetobacter; Clostridium sensu stricto 1 was abundant in the control group and Corynebacterium_1 was abundant in the DB group. Compared with the control group, the abundance of Burkholderia-Caballeronia-Paraburkholderia was 2.36-fold lower in the DB group. Linear discriminant analysis Effect Size (LEfSe) analysis revealed Burkholderia-Caballeronia-Paraburkholderia, SC_I_84_unclassified, Nonmyxobacteria and Succinvibrio to be the major biomarkers in the control group and Catenibacterium and Lachnospiraceae NK4A136 group to be the major biomarkers in the DB group. To explore the performance of these optimal marker models, receiver operational characteristic curve analysis was performed, and the average area under the curve value of Burkholderia-Caballeronia-Paraburkholderia was 0.7448. Burkholderia cepacia isolated from normal human eyelashes was fermented, and the Demodex mites isolated from patient eyelashes were cultured together with its fermented supernatant. The results showed that the fermentation supernatant could significantly reduce the survival time of the Demodex mites, suggesting the potential therapeutic value of this bacterium against Demodex. CONCLUSIONS: The composition of the bacterial community in the eyelashes of DB patients differed from that in eyelashes of healthy volunteers, revealing a decrease in bacterial diversity in infested eyelashes. This decrease may be related to the occurrence and development of DB. The supernatant of Burkholderia cepacia culture medium was found to inhibit the growth of Demodex in eyelash hair follicles, providing a new insight with potential applications for the clinical treatment of Demodex infestation.


Assuntos
Blefarite , Infecções Oculares Parasitárias , Pestanas , Infestações por Ácaros , Ácaros , Animais , Humanos , Infestações por Ácaros/epidemiologia , Blefarite/diagnóstico , Blefarite/epidemiologia , Bactérias/genética , Biomarcadores , DNA Ribossômico , Infecções Oculares Parasitárias/epidemiologia
14.
Front Neurosci ; 17: 1259652, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37799340

RESUMO

Introduction: In the medical field, electronic medical records contain a large amount of textual information, and the unstructured nature of this information makes data extraction and analysis challenging. Therefore, automatic extraction of entity information from electronic medical records has become a significant issue in the healthcare domain. Methods: To address this problem, this paper proposes a deep learning-based entity information extraction model called Entity-BERT. The model aims to leverage the powerful feature extraction capabilities of deep learning and the pre-training language representation learning of BERT(Bidirectional Encoder Representations from Transformers), enabling it to automatically learn and recognize various entity types in medical electronic records, including medical terminologies, disease names, drug information, and more, providing more effective support for medical research and clinical practices. The Entity-BERT model utilizes a multi-layer neural network and cross-attention mechanism to process and fuse information at different levels and types, resembling the hierarchical and distributed processing of the human brain. Additionally, the model employs pre-trained language and sequence models to process and learn textual data, sharing similarities with the language processing and semantic understanding of the human brain. Furthermore, the Entity-BERT model can capture contextual information and long-term dependencies, combining the cross-attention mechanism to handle the complex and diverse language expressions in electronic medical records, resembling the information processing method of the human brain in many aspects. Additionally, exploring how to utilize competitive learning, adaptive regulation, and synaptic plasticity to optimize the model's prediction results, automatically adjust its parameters, and achieve adaptive learning and dynamic adjustments from the perspective of neuroscience and brain-like cognition is of interest. Results and discussion: Experimental results demonstrate that the Entity-BERT model achieves outstanding performance in entity recognition tasks within electronic medical records, surpassing other existing entity recognition models. This research not only provides more efficient and accurate natural language processing technology for the medical and health field but also introduces new ideas and directions for the design and optimization of deep learning models.

15.
J Biol Chem ; 286(14): 12202-12, 2011 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-21262961

RESUMO

Dantrolene is believed to stabilize interdomain interactions between the NH2-terminal and central regions of ryanodine receptors by binding to the NH2-terminal residues 590-609 in skeletal ryanodine receptor (RyR1) and residues 601-620 in cardiac ryanodine receptor (RyR2). To gain further insight into the structural basis of dantrolene action, we have attempted to localize the dantrolene-binding sequence in RyR1/RyR2 by using GFP as a structural marker and three-dimensional cryo-EM. We inserted GFP into RyR2 after residues Arg-626 and Tyr-846 to generate GFP-RyR2 fusion proteins, RyR2Arg-626-GFP and RyR2Tyr-846-GFP. Insertion of GFP after residue Arg-626 abolished the binding of a bulky GST- or cyan fluorescent protein-tagged FKBP12.6 but not the binding of a smaller, nontagged FKBP12.6, suggesting that residue Arg-626 and the dantrolene-binding sequence are located near the FKBP12.6-binding site. Using cryo-EM, we have mapped the three-dimensional location of Tyr-846-GFP to domain 9, which is also adjacent to the FKBP12.6-binding site. To further map the three-dimensional location of the dantrolene-binding sequence, we generated 10 FRET pairs based on four known three-dimensional locations (FKBP12.6, Ser-437-GFP, Tyr-846-GFP, and Ser-2367-GFP). Based on the FRET efficiencies of these FRET pairs and the corresponding distance relationships, we mapped the three-dimensional location of Arg-626-GFP or -cyan fluorescent protein, hence the dantrolene-binding sequence, to domain 9 near the FKBP12.6-binding site but distant to the central region around residue Ser-2367. An allosteric mechanism by which dantrolene stabilizes interdomain interactions between the NH2-terminal and central regions is proposed.


Assuntos
Dantroleno/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/química , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Proteínas de Ligação a Tacrolimo/metabolismo , Sítios de Ligação , Cálcio , Linhagem Celular , Microscopia Crioeletrônica , Recuperação de Fluorescência Após Fotodegradação , Transferência Ressonante de Energia de Fluorescência , Humanos , Immunoblotting , Imunoprecipitação , Ligação Proteica , Canal de Liberação de Cálcio do Receptor de Rianodina/genética
16.
J Cell Sci ; 123(Pt 10): 1775-84, 2010 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-20427316

RESUMO

Naturally occurring mutations in the cardiac ryanodine receptor (RyR2) have been linked to certain types of cardiac arrhythmias and sudden death. Two mutation hotspots that lie in the N-terminal and central regions of RyR2 are predicted to interact with one another and to form an important channel regulator switch. To monitor the conformational dynamics involving these regions, we generated a fluorescence resonance energy transfer (FRET) pair. A yellow fluorescent protein (YFP) was inserted into RyR2 after residue Ser437 in the N-terminal region, and a cyan fluorescent protein (CFP) was inserted after residue Ser2367 in the central region, to form a dual YFP- and CFP-labeled RyR2 (RyR2(S437-YFP/S2367-CFP)). We transfected HEK293 cells with RyR2(S437-YFP/S2367-CFP) cDNAs, and then examined them by using confocal microscopy and by measuring the FRET signal in live cells. The FRET signals are influenced by modulators of RyR2, by domain peptides that mimic the effects of disease causing RyR2 mutations, and by various drugs. Importantly, FRET signals were also readily detected in cells co-transfected with single CFP (RyR2(S437-YFP)) and single YFP (RyR2(S2367-CFP)) labeled RyR2, indicating that the interaction between the N-terminal and central mutation regions is an inter-subunit interaction. Our studies demonstrate that FRET analyses of this CFP- and YFP-labeled RyR2 can be used not only for investigating the conformational dynamics associated with RyR2 channel gating, but potentially, also for identifying drugs that are capable of stabilizing the conformations of RyR2.


Assuntos
Arritmias Cardíacas/metabolismo , Canais de Cálcio/metabolismo , Miocárdio/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Arritmias Cardíacas/complicações , Arritmias Cardíacas/genética , Linhagem Celular , Clonagem Molecular , Morte Súbita Cardíaca/etiologia , Transferência Ressonante de Energia de Fluorescência , Predisposição Genética para Doença , Humanos , Microscopia Confocal , Modelos Biológicos , Mutação/genética , Polimorfismo Genético , Conformação Proteica , Domínios e Motivos de Interação entre Proteínas/genética , Canal de Liberação de Cálcio do Receptor de Rianodina/química , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Transgenes/genética
17.
Zhonghua Yi Xue Za Zhi ; 92(4): 232-5, 2012 Jan 31.
Artigo em Chinês | MEDLINE | ID: mdl-22490792

RESUMO

OBJECTIVE: To explore the variance of mean platelet volume (MPV) in subjects with normal glucose tolerance (NGT), impaired glucose regulation (IGR) and type 2 diabetes mellitus (T2DM) and risk factors of MPV changes and analyze the relationship between MPV and diabetic peripheral artery disease (PAD). METHODS: A total of 173 subjects were enrolled into this observational cross-sectional study. They were divided into 3 groups: NGT (n = 41), IGR (n = 41) and T2DM (n = 91). Blood pressure (BP), platelet count (PLT), mean platelet volume (MPV) and such fasting serum lipids as triglycerides (TG), total cholesterol (TC), high density lipoprotein (HDL-C), low density lipoprotein (LDL-C), fast plasma glucose (FPG) and serum uric acid (UA) were determined. HbA1c and ankle/brachial index (ABI) were also measured. RESULTS: (1) The MPV level was highest in the T2DM group (12.3 ± 1.5) fl. And it was significantly higher in the IGR group than in the NGT group (9.7 ± 0.9 vs 8.0 ± 0.9) fl (P < 0.01). It was significantly higher in diabetics with HbA1c ≥ 7% (13.2 ± 1.9) fl than in patients those with HbA1c 7% (11.8 ± 1.7) fl (P < 0.01); (2) Stepwise multiple regression analysis showed that age, serum creatinine, LDL-C and fasting plasma glucose (FPG) were important influencing factors of MPV (adjusted R(2) = 0.891); (3) Multiple Logistic regression analysis indicated that MPV was an important risk factor of PAD. CONCLUSION: The MPV level in T2DM is significantly higher than that in NGT and IGR subjects. FPG, LDL-C, age and serum creatinine are important contributors to MPV. And MPV is an important risk factor of PAD.


Assuntos
Plaquetas , Diabetes Mellitus Tipo 2/sangue , Angiopatias Diabéticas , Doença Arterial Periférica/etiologia , Idoso , Estudos Transversais , Diabetes Mellitus Tipo 2/complicações , Feminino , Humanos , Extremidade Inferior/irrigação sanguínea , Masculino , Pessoa de Meia-Idade , Contagem de Plaquetas
18.
Zhongguo Yi Liao Qi Xie Za Zhi ; 36(3): 185-7, 198, 2012 May.
Artigo em Chinês | MEDLINE | ID: mdl-22916475

RESUMO

OBJECTIVE: Changing the current situation that doctors carry large amounts of paper medical records doctor's advice during clinical examination to improve the efficiency of examination. METHOD: Analysis of current business demand in doctor's clinical work, followed with a comprehensive improvement program. RESULT: Design a Tablet PC system comply with doctor's clinical demand in both software and hardware. CONCLUSION: By using the Tablet PC physicians improve the efficiency of work, realize the reengineering and optimization of traditional health services and management process.


Assuntos
Computadores de Mão , Sistemas de Informação Hospitalar , Desenho de Equipamento , Design de Software
19.
Front Med (Lausanne) ; 9: 846709, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35237636

RESUMO

OBJECTIVE: To analyze the incidence and risk factors of dry eye in children from a myopia outpatient clinic via a questionnaire and Keratograph 5M. METHODS: A cross-sectional study was performed. sThere were 214 children (428 eyes) selected from the myopia outpatient clinic of the affiliated Eye Hospital of Shandong First Medical University from July 2021 to September 2021, including 105 boys (210 eyes) and 109 girls (218 eyes), with an average age of 10.1 ± 2.5 years. The incidence rate and influence factors for dry eye were calculated. RESULTS: Thirty-four of 214 children were diagnosed with dry eye, accounting for 15.9% of the patients. The correlation between fussy eating and the tear meniscus height was statistically significant (Z = -2.158, p = 0.039), along with the correlation between short-distance use of eyes and the tear meniscus height (Z = -2.135, p = 0.033). The degree of meibomian gland deficiency was graded. The meibomian gland was graded as grade 1 in 242 eyes (68.9%), grade 2 in 104 eyes (29.6%), and grade 3 in 5 eyes (1.4%). There was a significant difference in the correlation between eye rubbing and the incidence of dry eye in children (Z = -2.747, p = 0.008). There was also a significant difference in the correlation between picky eating and the incidence of dry eye in children (Z = -2.347; p = 0.024). There was a statistically significant correlation between the time of looking at electronic products and the morphology of the meibomian gland (Z = -2.201, p = 0.028). The results showed that the effect of mild and moderate ametropia on the non-invasive tear breakup time in children was statistically significant (Z = -2.027; p = 0.043). CONCLUSION: There is a high incidence of dry eye in children in the myopia outpatient clinic. There is a significant correlation between picky eating, eye rubbing, and the incidence of dry eye. Looking at electronic products for a long time will also affect the morphology of the meibomian gland in children.

20.
JAMA Cardiol ; 7(1): 84-92, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34730774

RESUMO

Importance: Calcium-release deficiency syndrome (CRDS), which is caused by loss-of-function variants in cardiac ryanodine receptor 2 (RyR2), is an emerging cause of ventricular fibrillation. However, the lack of complex polymorphic/bidirectional ventricular tachyarrhythmias during exercise stress testing (EST) may distinguish it from catecholaminergic polymorphic ventricular tachycardia (CPVT). Recently, in the first clinical series describing the condition, mouse and human studies showed that the long-burst, long-pause, short-coupled ventricular extra stimulus (LBLPS) electrophysiology protocol reliably induced CRDS ventricular arrhythmias. Data from larger populations with CRDS and its associated spectrum of disease are lacking. Objective: To further insight into CRDS through international collaboration. Design, Setting, and Participants: In this multicenter observational cohort study, probands with unexplained life-threatening arrhythmic events and an ultrarare RyR2 variant were identified. Variants were expressed in HEK293 cells and subjected to caffeine stimulation to determine their functional impact. Data were collected from September 1, 2012, to March 6, 2021, and analyzed from August 9, 2015, to March 6, 2021. Main Outcomes and Measures: The functional association of RyR2 variants found in putative cases of CRDS and the associated clinical phenotype(s). Results: Of 10 RyR2 variants found in 10 probands, 6 were loss-of-function, consistent with CRDS (p.E4451del, p.F4499C, p.V4606E, p.R4608Q, p.R4608W, and p.Q2275H) (in 4 [67%] male and 2 [33%] female probands; median age at presentation, 22 [IQR, 8-34] years). In 5 probands with a documented trigger, 3 were catecholamine driven. During EST, 3 probands with CRDS had no arrhythmias, 1 had a monomorphic couplet, and 2 could not undergo EST (deceased). Relatives of the decedents carrying the RyR2 variant did not have EST results consistent with CPVT. After screening 3 families, 13 relatives were diagnosed with CRDS, including 3 with previous arrhythmic events (23%). None had complex ventricular tachyarrhythmias during EST. Among the 19 confirmed cases with CRDS, 10 had at least 1 life-threatening event at presentation and/or during a median follow-up of 7 (IQR, 6-18) years. Two of the 3 device-detected ventricular fibrillation episodes were induced by a spontaneous LBLPS-like sequence. ß-Blockers were used in 16 of 17 surviving patients (94%). Three of 16 individuals who were reportedly adherent to ß-blocker therapy (19%) had breakthrough events. Conclusions and Relevance: The results of this study suggest that calcium-release deficiency syndrome due to RyR2 loss-of-function variants mechanistically and phenotypically differs from CPVT. Ventricular fibrillation may be precipitated by a spontaneous LBLPS-like sequence of ectopy; however, CRDS remains difficult to recognize clinically. These data highlight the need for better diagnostic tools and treatments for this emerging condition.


Assuntos
Morte Súbita Cardíaca/prevenção & controle , Mutação , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Taquicardia Ventricular/genética , Adolescente , Adulto , Criança , Morte Súbita Cardíaca/epidemiologia , Eletrocardiografia , Feminino , Seguimentos , Saúde Global , Humanos , Masculino , Morbidade/tendências , Fenótipo , Estudos Prospectivos , Estudos Retrospectivos , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Taquicardia Ventricular/epidemiologia , Taquicardia Ventricular/metabolismo , Adulto Jovem
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