Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 270
Filtrar
1.
J Biol Chem ; 300(2): 105599, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38159853

RESUMO

It is known that the recommended dietary allowance of selenium (Se) is dangerously close to its tolerable upper intake level. Se is detoxified and excreted in urine as trimethylselenonium ion (TMSe) when the amount ingested exceeds the nutritional level. Recently, we demonstrated that the production of TMSe requires two methyltransferases: thiopurine S-methyltransferase (TPMT) and indolethylamine N-methyltransferase (INMT). In this study, we investigated the substrate recognition mechanisms of INMT and TPMT in the Se-methylation reaction. Examination of the Se-methyltransferase activities of two paralogs of INMT, namely, nicotinamide N-methyltransferase and phenylethanolamine N-methyltransferase, revealed that only INMT exhibited Se-methyltransferase activity. Consistently, molecular dynamics simulations demonstrated that dimethylselenide was preferentially associated with the active center of INMT. Using the fragment molecular orbital method, we identified hydrophobic residues involved in the binding of dimethylselenide to the active center of INMT. The INMT-L164R mutation resulted in a deficiency in Se- and N-methyltransferase activities. Similarly, TPMT-R152, which occupies the same position as INMT-L164, played a crucial role in the Se-methyltransferase activity of TPMT. Our findings suggest that TPMT recognizes negatively charged substrates, whereas INMT recognizes electrically neutral substrates in the hydrophobic active center embedded within the protein. These observations explain the sequential requirement of the two methyltransferases in producing TMSe.


Assuntos
Metiltransferases , Selênio , Metiltransferases/genética , Metiltransferases/metabolismo , Selênio/metabolismo , Metilação , Ativação Enzimática , Interações Hidrofóbicas e Hidrofílicas , Ligação Proteica , Humanos
2.
J Cardiovasc Electrophysiol ; 35(1): 97-110, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37897084

RESUMO

INTRODUCTION: The clinical outcomes and mechanisms of delayed responses to cardiac resynchronization therapy (CRT) remain unclear. We aimed to investigate the differences in outcomes and gain insight into the mechanisms of early and delayed responses to CRT. METHODS: This retrospective study included 110 patients who underwent CRT implantation. Positive response to CRT was defined as ≥15% reduction of left ventricular (LV) end-systolic volume on echocardiography at 1 year (early phase) and 3 years (delayed phase) after implantation. The latest mechanical activation site (LMAS) of the LV was identified using two-dimensional speckle-tracking radial strain analysis. RESULTS: Seventy-eight (71%) patients exhibited an early response 1 year after CRT implantation. Of 32 non-responders in the early phase, 12 (38%) demonstrated a delayed response, and 20 (62%) were classified as non-responders after 3 years. During the follow-up time of 10.3 ± 0.5 years, the delayed and early responders had a similar prognosis of mortality and heart failure (HF) hospitalization. In contrast, non-responders had a worse prognosis. Multivariate analysis revealed that a longer duration (months) between initial HF hospitalization and CRT (odds ratio [OR]: 1.126; 95% confidence interval [CI]: 1.036-1.222; p = .005), non-exact concordance of LV lead location with LMAS (OR: 32.744; 95% CI: 1.101-973.518; p = .044), and pre-QRS duration (OR: 0.901; 95% CI: 0.827-0.981; p = .016) were independent predictors of delayed response to CRT compared with early response. CONCLUSION: The prognoses were similar regardless of the response time after CRT. A longer history of HF, suboptimal LV lead position, and shorter pre-QRS duration were related to delayed response than early response.


Assuntos
Terapia de Ressincronização Cardíaca , Insuficiência Cardíaca , Humanos , Terapia de Ressincronização Cardíaca/métodos , Estudos Retrospectivos , Resultado do Tratamento , Ecocardiografia , Prognóstico , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/terapia
3.
Int J Mol Sci ; 25(11)2024 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-38891954

RESUMO

While research has identified several inhibitors of the main protease (Mpro) of SARS-CoV-2, a significant portion of these compounds exhibit reduced activity in the presence of reducing agents, raising concerns about their effectiveness in vivo. Furthermore, the conventional biosafety level 3 (BSL-3) for cellular assays using viral particles poses a limitation for the widespread evaluation of Mpro inhibitor efficacy in a cell-based assay. Here, we established a BSL-1 compatible cellular assay to evaluate the in vivo potential of Mpro inhibitors. This assay utilizes mammalian cells expressing a tagged Mpro construct containing N-terminal glutathione S-transferase (GST) and C-terminal hemagglutinin (HA) tags and monitors Mpro autodigestion. Using this method, GC376 and boceprevir effectively inhibited Mpro autodigestion, suggesting their potential in vivo activity. Conversely, carmofur and ebselen did not exhibit significant inhibitory effects in this assay. We further investigated the inhibitory potential of selenoneine on Mpro using this approach. Computational analyses of binding energies suggest that noncovalent interactions play a critical role in facilitating the covalent modification of the C145 residue, leading to Mpro inhibition. Our method is straightforward, cost-effective, and readily applicable in standard laboratories, making it accessible to researchers with varying levels of expertise in infectious diseases.


Assuntos
Antivirais , Azóis , Proteases 3C de Coronavírus , Isoindóis , Compostos Organosselênicos , Prolina , SARS-CoV-2 , Antivirais/farmacologia , Antivirais/química , Humanos , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/enzimologia , Compostos Organosselênicos/farmacologia , Compostos Organosselênicos/química , Isoindóis/farmacologia , Proteases 3C de Coronavírus/antagonistas & inibidores , Proteases 3C de Coronavírus/metabolismo , Azóis/farmacologia , Azóis/química , Prolina/análogos & derivados , Prolina/farmacologia , Prolina/química , Simulação de Acoplamento Molecular , Inibidores de Proteases/farmacologia , Inibidores de Proteases/química , Tratamento Farmacológico da COVID-19 , COVID-19/virologia , Células HEK293 , Lactamas , Leucina/análogos & derivados , Ácidos Sulfônicos
4.
J Cardiovasc Electrophysiol ; 34(3): 627-637, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36651347

RESUMO

INTRODUCTION: Diagnosis of outflow tract ventricular arrhythmia (OTVA) localization by an electrocardiographic complex is key to successful catheter ablation for OTVA. However, diagnosing the origin of OTVA with a precordial transition in lead V3 (V3TZ) is challenging. This study aimed to create the best practical electrocardiogram algorithm to differentiate the left ventricular outflow tract (LVOT) from the right ventricular outflow tract (RVOT) of OTVA origin with V3TZ using machine learning. METHODS: Of 498 consecutive patients undergoing catheter ablation for OTVA, we included 104 patients who underwent ablation for OTVA with V3TZ and identified the origin of LVOT (n = 62) and RVOT (n = 42) from the results. We analyzed the standard 12-lead electrocardiogram preoperatively and measured 128 elements in each case. The study population was randomly divided into training group (70%) and testing group (30%), and decision tree analysis was performed using the measured elements as features. The performance of the algorithm created in the training group was verified in the testing group. RESULTS: Four measurements were identified as important features: the aVF/II R-wave ratio, the V2S/V3R index, the QRS amplitude in lead V3, and the R-wave deflection slope in lead V3. Among them, the aVF/II R-wave ratio and the V2S/V3R index had a particularly strong influence on the algorithm. The performance of this algorithm was extremely high, with an accuracy of 94.4%, precision of 91.5%, recall of 100%, and an F1-score of 0.96. CONCLUSIONS: The novel algorithm created using machine learning is useful in diagnosing the origin of OTVA with V3TZ.


Assuntos
Ablação por Cateter , Taquicardia Ventricular , Humanos , Algoritmos , Arritmias Cardíacas , Eletrocardiografia/métodos , Ventrículos do Coração , Aprendizado de Máquina
5.
Chemistry ; 29(8): e202203396, 2023 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-36354746

RESUMO

Foeniculoxin is a major phytotoxin produced by Italian strains of Phomopsis foeniculi. The first total synthesis is described utilizing the ene reaction and Sonogashira cross-coupling reaction as key steps. The absolute configuration of the C6' was determined using chiral separation and an advanced Mosher's method. The phytotoxicity of the synthesized compound was demonstrated via syringe-based infiltration into Chenopodium album and Arabidopsis thaliana leaves. Synthetic foeniculoxin induced various defects in A. thaliana leaf cells before lesion formation, including protein leakage into the cytoplasm from both chloroplasts and mitochondria and mitochondrial rounding and swelling. Furthermore, foeniculoxin and the antibiotic hygromycin B caused similar agglomeration of mitochondria around chloroplasts, highlighting this event as a common component in the early stages of plant cell death.


Assuntos
Alcaloides , Arabidopsis , Toxinas Biológicas , Toxinas Biológicas/toxicidade , Folhas de Planta
6.
Environ Sci Technol ; 57(48): 19066-19077, 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-37943968

RESUMO

Pollution by chemicals and waste impacts human and ecosystem health on regional, national, and global scales, resulting, together with climate change and biodiversity loss, in a triple planetary crisis. Consequently, in 2022, countries agreed to establish an intergovernmental science-policy panel (SPP) on chemicals, waste, and pollution prevention, complementary to the existing intergovernmental science-policy bodies on climate change and biodiversity. To ensure the SPP's success, it is imperative to protect it from conflicts of interest (COI). Here, we (i) define and review the implications of COI, and its relevance for the management of chemicals, waste, and pollution; (ii) summarize established tactics to manufacture doubt in favor of vested interests, i.e., to counter scientific evidence and/or to promote misleading narratives favorable to financial interests; and (iii) illustrate these with selected examples. This analysis leads to a review of arguments for and against chemical industry representation in the SPP's work. We further (iv) rebut an assertion voiced by some that the chemical industry should be directly involved in the panel's work because it possesses data on chemicals essential for the panel's activities. Finally, (v) we present steps that should be taken to prevent the detrimental impacts of COI in the work of the SPP. In particular, we propose to include an independent auditor's role in the SPP to ensure that participation and processes follow clear COI rules. Among others, the auditor should evaluate the content of the assessments produced to ensure unbiased representation of information that underpins the SPP's activities.


Assuntos
Conflito de Interesses , Ecossistema , Humanos , Poluição Ambiental , Biodiversidade
7.
Pacing Clin Electrophysiol ; 46(4): 341-345, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36914408

RESUMO

Deep septal ventricular pacing is a recently developed physiological pacing modality with good efficacy; however, it has a potential risk of unusual complications. Here, we report a patient with pacing failure and spontaneous, complete lead dislodgement after >2 years of deep septal pacing, possibly caused by systemic bacterial infection and specific lead behavior in the septal myocardium. This case report may implicate a hidden risk of unusual complications in deep septal pacing.


Assuntos
Estimulação Cardíaca Artificial , Ventrículos do Coração , Humanos , Estimulação Cardíaca Artificial/efeitos adversos , Estimulação Cardíaca Artificial/métodos
8.
Proc Biol Sci ; 289(1983): 20221176, 2022 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-36126683

RESUMO

The soil is a rich ecosystem where many ecological interactions are mediated by small molecules, and in which amoebae are low-level predators and also prey. The social amoeba Dictyostelium discoideum has a high genomic potential for producing polyketides to mediate its ecological interactions, including the unique 'Steely' enzymes, consisting of a fusion between a fatty acid synthase and a chalcone synthase. We report here that D. discoideum further increases its polyketide potential by using the StlB Steely enzyme, and a downstream chlorinating enzyme, to make both a chlorinated signal molecule, DIF-1, during its multi-cellular development, and a set of abundant polyketides in terminally differentiated stalk cells. We identify one of these as a chlorinated dibenzofuran with potent anti-bacterial activity. To do this, StlB switches expression from prespore to stalk cells in late development and is cleaved to release the chalcone synthase domain. Expression of this domain alone in StlB null cells allows synthesis of the stalk-associated, chlorinated polyketides. Thus, by altered expression and processing of StlB, cells make first a signal molecule, and then abundant secondary metabolites, which we speculate help to protect the mature spores from bacterial infection.


Assuntos
Dictyostelium , Policetídeos , Dibenzofuranos Policlorados/metabolismo , Dictyostelium/genética , Ecossistema , Ácido Graxo Sintases/metabolismo , Policetídeo Sintases/metabolismo , Policetídeos/metabolismo , Solo
9.
J Cardiovasc Electrophysiol ; 33(7): 1515-1528, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35598302

RESUMO

INTRODUCTION: Reactive atrial-based antitachycardia pacing (rATP) in patients with cardiac implantable electronic devices (CIEDs) suppresses the progression of atrial fibrillation (AF) to the persistent form. However, the clinical factors associated with successful reactive atrial-based antitachycardia pacing (rATP) treatment are unknown. This study aimed to examine the predictors of high rATP efficacy in patients with CIEDs. METHODS: The data of 101,325 rATP-treated atrial tachyarrhythmia (AT/AF) episodes in 51 patients, obtained through remote monitoring and device interrogation, were analyzed. The study population was divided into the high and low efficacy groups based on the overall median success rate of rATP. Clinical characteristics were compared between the two groups. RESULTS: During a follow-up period of 28.6 ± 8.6 months, the median success rate was 43.7% (31.5%-64.9%). The prevalence of a history of catheter ablation of AF was significantly higher in the high efficacy group than in the low efficacy group (73.0% vs. 44.0%, p = .048) and was the only independent predictor of high rATP efficacy (odds ratio, 3.45; p = .038). The rATP success rate in patients with (n = 30) and without (n = 21) a history of catheter ablation was 53.9% (40.0%-67.5%) and 36.4% (22.2%-47.7%), respectively (p = .012). The effect of rATP after ablation was more pronounced in patients with long cycle length episodes (≥75% of AT/AF sequences having a cycle length of 200-449 ms) (67.3% [46.0%-73.6%] vs. 30.6% [18.1%-60.3%], p = .027). The high efficacy group had a significantly lower incidence of AT/AF lasting ≥1, ≥7, and ≥30 days than the low efficacy group. CONCLUSION: rATP combined with catheter ablation therapy is effective in suppressing AT/AF.


Assuntos
Fibrilação Atrial , Ablação por Cateter , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/cirurgia , Ablação por Cateter/efeitos adversos , Eletrônica , Átrios do Coração/cirurgia , Humanos , Resultado do Tratamento
10.
Environ Sci Technol ; 56(5): 2936-2949, 2022 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-35167273

RESUMO

The Stockholm Convention is key to addressing the global threats of persistent organic pollutants (POPs) to humanity and the environment. It has been successful in identifying new POPs, but its national implementation remains challenging, particularly by low- and middle-income Parties. Concerted action is needed to assist Parties in implementing the Convention's obligations. This analysis aims to identify and recommend research and scientific support needed for timely implementation of the Convention. We aim this analysis at scientists and experts from a variety of natural and social sciences and from all sectors (academia, civil society, industry, and government institutions), as well as research funding agencies. Further, we provide practical guidance to scientists and experts to promote the visibility and accessibility of their work for the Convention's implementation, followed by recommendations for sustaining scientific support to the Convention. This study is the first of a series on analyzing policy needs for scientific evidence under global governance on chemicals and waste.


Assuntos
Poluentes Ambientais , Poluentes Ambientais/análise , Políticas
11.
BMC Cardiovasc Disord ; 22(1): 13, 2022 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-35065605

RESUMO

BACKGROUND: The efficacy of pulmonary vein isolation (PVI) alone is not guaranteed for persistent atrial fibrillation (PeAF), and it is unclear which type of ablation approach should be applied in addition to PVI. This study aimed to compare outcomes and prognosis between empirical linear ablation and low-voltage area (LVA) ablation after PVI for PeAF. METHODS: We enrolled 128 patients with PeAF who were assigned to the linear ablation group (n = 64) and the LVA ablation group (n = 64) using a propensity score-matched model. After PVI and cardioversion, the patients underwent either empirical linear ablation or LVA ablation during sinus rhythm. All patients in the linear ablation group underwent both roof line and mitral valve isthmus (MVI) ablations. An electrical-guided ablation targeting LVA (< 0.5 mV) was performed in the LVA group. When there was no LVA in the LVA group, only PVI was applied. We compared the procedural outcomes and recurrence after ablation between the two groups. RESULTS: The baseline characteristics were well-balanced between the two groups. Fifty patients had LVA (22 and 28 patients in the linear and LVA groups). The roof and MVI lines were completed in 100% and 96.9% of the patients. During the mean follow-up of 279.5 ± 161.3 days, the LVA group had significantly lower recurrence than the linear group (15 patients [23%] vs. 29 patients [45%], p = 0.014). Thirty-five patients were prescribed antiarrhythmic drugs during the follow-up period (linear group, n = 17; LVA group, n = 18); amiodarone and bepridil were administered to most of the patients (15 and 17 patients, respectively). The difference in the prognosis was relevant among the patients with LVA, while this trend was not observed in those without LVA. The LVA ablation group demonstrated significantly lower radiofrequency energy and shorter procedural time compared to the linear ablation group. The recurrence of atrial flutter was more likely to occur in the linear group than in the LVA group (14 [22%] vs. 6 [9.4%], p = 0.052). CONCLUSION: The electrophysiological-guided LVA ablation is more effective than empirical linear ablation in PeAF patients with LVA. Unnecessary empirical linear ablation might have a risk of iatrogenic gap and atrial flutter recurrence.


Assuntos
Fibrilação Atrial/cirurgia , Ablação por Cateter/métodos , Técnicas Eletrofisiológicas Cardíacas/métodos , Frequência Cardíaca/fisiologia , Pontuação de Propensão , Veias Pulmonares/cirurgia , Cirurgia Assistida por Computador/métodos , Idoso , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/fisiopatologia , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Imageamento Tridimensional , Masculino , Prognóstico , Estudos Retrospectivos , Fatores de Tempo
12.
Ann Noninvasive Electrocardiol ; 27(5): e12991, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35802829

RESUMO

BACKGROUND: The current study aimed to evaluate changes in electrical depolarization and repolarization parameters after His-bundle pacing (HBP) compared with right ventricular pacing (RVP) and its association with ventricular arrhythmia (VA). METHODS: Forty-one patients (13 with HBP, 14 with RVP, and 14 controls [AAI mode]) were evaluated. After continuous pacing algorithm, QRS duration, QT interval, QTc, JT interval, T-peak to T-end (Tpe), and Tpe/QT ratio were measured on electrocardiography at baseline and 1 week, 1 month, and 6 months postoperatively. We investigated VA occurrence and adverse events after implantation. RESULTS: At 6 months, QRS duration was significantly shorter in the HBP (121.6 ± 15.6 ms) than in the RVP (150.1 ± 14.9 ms) group. The QT intervals were lower in the HBP (424.0 ± 40.9 ms) and control (405.9 ± 23.0 ms) groups than in the RVP (453.0 ± 40.2 ms) group. The Tpe and Tpe/QT ratios at 6 months differed significantly between the HBP and RVP groups (Tpe, 69.8 ± 19.7 ms vs 87.4 ± 11.9 ms and Tpe/QT, 0.16 ± 0.03 vs 0.19 ± 0.02, respectively). The Tpe and Tpe/QT ratios were similarly shortened in the HBP and control groups. VA occurred less frequently in the HBP (15%) and control (7.1%) groups than in the RVP (50%) group (p = 0.020). The non-RVP group showed significantly lower rates of VA and major adverse events than the RVP group. Patients with VA demonstrated significantly longer QRS duration, QT interval, Tpe, and Tpe/QT at 6 months than those without VA. CONCLUSION: HBP showed better depolarization and repolarization stability than RVP.


Assuntos
Fascículo Atrioventricular , Estimulação Cardíaca Artificial , Arritmias Cardíacas , Eletrocardiografia , Frequência Cardíaca , Ventrículos do Coração , Humanos , Resultado do Tratamento
13.
J Appl Toxicol ; 42(9): 1503-1509, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35274318

RESUMO

There is increasing concern about multiple high concentration exposure to toxins in disaster and emergency situations. However, conventional toxicology testing methods may not adequately address these situations. Thus, we assessed whether the toxic effects of exposure in the adulthood differ depending on the presence or absence of neonatal exposure to Tris (1,3-dichloro-2-propyl) phosphate (TDCIPP) in male rats to investigate the effects of exposure history of chemicals. In the neonatal stage [postnatal days (PNDs) 1-7], animals were treated with either sesame oil (5 ml/kg/day) as a control or TDCIPP (250 mg/kg/day) dissolved in sesame oil. In adulthood (PND 101-107), animals were treated with either sesame oil (5 ml/kg/day) or TDCIPP (650 mg/kg/day). One day after the final administration, dissection was performed, and body and organ weight, hematology, blood biochemistry, and histopathology were examined. The results demonstrated that the toxic effects of TDCIPP exposure in adulthood on adrenal gland size, serum iron content, and unsaturated iron binding capacity were enhanced by TDCIPP exposure in the neonatal stage. From these findings, it was indicated that the toxic effects of TDCIPP exposure in the adult stage are affected by pediatric exposure. These results suggest that the toxic effects of high-dose and long-term unsteady exposure to chemicals in large-scale disasters may change based on the exposure history of chemicals.


Assuntos
Retardadores de Chama , Compostos Organofosforados , Animais , Retardadores de Chama/toxicidade , Humanos , Ferro , Masculino , Organofosfatos/toxicidade , Compostos Organofosforados/toxicidade , Fosfatos , Ratos , Óleo de Gergelim
14.
Int Heart J ; 63(3): 633-638, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35650163

RESUMO

We report the usefulness of novel automated anti-tachycardia pacing (ATP) for ventricular tachycardia (VT) termination evaluated in an electrophysiology study. This intrinsic, automated ATP with an implanted cardiac resynchronization therapy-defibrillator successfully terminated the sustained VT, which had not been suppressed by repetitive burst pacing from the electrode catheter. The reproduction of programed pacing of the automated ATP by a right ventricular electrode catheter was effective in terminating VT, and this termination was absolute and reproducible. Further detailed assessment in an electrophysiology study could highlight the algorithm of the automated ATP and its possible benefit in terminating the reentrant VT.


Assuntos
Terapia de Ressincronização Cardíaca , Taquicardia Ventricular , Trifosfato de Adenosina , Algoritmos , Morte , Eletrofisiologia , Humanos , Taquicardia Ventricular/terapia
15.
Int Heart J ; 63(1): 77-84, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35095080

RESUMO

Cerebral white matter hyperintensity (WMH) is highly prevalent among older adults. There is little information about the relationship among WMH extent, frailty status, and exercise capacity in older adults with cardiovascular disease (CVD). We assessed the association of WMH with frailty and exercise capacity in CVD patients.Seventy-eight stable older adults with CVD were evaluated for WMH, the Kihon Checklist (KCL), short physical performance battery score (SPPB), and cardiopulmonary exercise testing. WMH volume was quantified on brain magnetic resonance imaging. Patients were classified into 3 groups (using tertiles of 0.52% and 1.05%) according to WMH as a percentage of intracranial volume (ICV), and their KCL scores and exercise capacities were compared. The 3 WMH/ICV groups were mild (n = 26, 0.26% ± 0.14% of intracranial volume), moderate (n = 26, 0.70% ± 0.15%), and severe (n = 26, 1.75% ± 0.67%). Peak VO2 was 15.2 ± 3.7 mL kg-1 minute-1 (mild group), 12.9 ± 3.5 mL kg-1 min-1 (moderate), and 11.4 ± 2.3 mL kg-1 minute-1 (severe) (mild versus moderate, P = 0.049; mild versus severe, P = 0.001). Multivariate regression analysis showed significant associations of severe WMH/ICV with peak VO2 and SPPB. Cerebral WMH was strongly negatively associated with SPPB and peak VO2. WMH volume may be related to exercise capacity and frailty in stable older adult patients with CVD.


Assuntos
Doenças Cardiovasculares/complicações , Doenças Cardiovasculares/fisiopatologia , Tolerância ao Exercício/fisiologia , Fragilidade/complicações , Fragilidade/fisiopatologia , Substância Branca/patologia , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/diagnóstico , Teste de Esforço , Feminino , Fragilidade/diagnóstico por imagem , Humanos , Imageamento por Ressonância Magnética , Masculino , Tamanho do Órgão , Substância Branca/diagnóstico por imagem
16.
J Clin Biochem Nutr ; 71(1): 2-6, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35903601

RESUMO

Copper (Cu) participates in the biological redox reaction in the body, and its deficiency is fatal to the body. At the same time, Cu is extremely toxic when it exists in excess. Thus, the body has to tightly and spatiotemporally regulate the concentration of Cu within a physiological range by several groups of Cu-regulating proteins. However, entire mechanisms underlying the maintenance of Cu homeostasis in body and cells have not fully understood. It is necessary to analyze Cu itself in a body and in a cell to reveal the Cu homeostasis. In this review, recent advances in the analytical techniques to understand the Cu metabolism such as speciation, imaging and single-cell analysis of Cu were highlighted.

17.
Chem Res Toxicol ; 34(12): 2471-2484, 2021 12 20.
Artigo em Inglês | MEDLINE | ID: mdl-34841876

RESUMO

It is widely recognized that the toxicity of mercury (Hg) is attenuated by the simultaneous administration of selenium (Se) compounds in various organisms. In this study, we revealed the mechanisms underlying the antagonistic effect of sodium selenite (Na2SeO3) on inorganic Hg (Hg2+) toxicity in human hepatoma HepG2 cells. Observations by transmission electron microscopy indicated that HgSe (tiemannite) granules of up to 100 nm in diameter were accumulated in lysosomal-like structures in the cells. The HgSe granules were composed of a number of HgSe nanoparticles, each measuring less than 10 nm in diameter. No accumulation of HgSe nanoparticles in lysosomes was observed in the cells exposed to chemically synthesized HgSe nanoparticles. This suggests that intracellular HgSe nanoparticles were biologically generated from Na2SeO3 and Hg2+ ions transported into the cells and were not derived from HgSe nanoparticles formed in the extracellular fluid. Approximately 85% of biogenic HgSe remained in the cells at 72 h post culturing, indicating that biogenic HgSe was hardly excreted from the cells. Moreover, the cytotoxicity of Hg2+ was ameliorated by the simultaneous exposure to Na2SeO3 even before the formation of insoluble HgSe nanoparticles. Our data confirmed for the first time that HepG2 cells can circumvent the toxicity of Hg2+ through the direct interaction of Hg2+ with a reduced form of Se (selenide) to form HgSe nanoparticles via a Hg-Se soluble complex in the cells. Biogenic HgSe nanoparticles are considered the ultimate metabolite in the Hg detoxification process.


Assuntos
Mercúrio/efeitos adversos , Nanopartículas/efeitos adversos , Selênio/efeitos adversos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Células Hep G2 , Humanos , Mercúrio/metabolismo , Nanopartículas/metabolismo , Selênio/metabolismo , Células Tumorais Cultivadas
18.
J Org Chem ; 86(23): 16892-16900, 2021 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-34797078

RESUMO

A facile and regioselective synthesis of quinoxalines, an important motif in medicinal chemistry and materials sciences, was developed. Despite their prospective utility, the regioselective preparation of trisubstituted quinoxalines has not been previously established. In the reported system, hypervalent iodine reagents catalyzed the annulation between α-iminoethanones and o-phenylenediamines in a chemo/regioselective manner to afford trisubstituted quinoxalines. Excellent regioselectivities (6:1 to 1:0) were achieved using [bis(trifluoroacetoxy)iodo]benzene and [bis(trifluoroacetoxy)iodo]pentafluorobenzene as annulation catalysts.


Assuntos
Iodo , Quinoxalinas , Indicadores e Reagentes , Iodetos , Estudos Prospectivos
19.
Org Biomol Chem ; 19(27): 6038-6044, 2021 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-33982042

RESUMO

Cynaropicrin is found in artichoke (Cynara scolymus) and is the source of its bitter taste and it is a sesquiterpene lactone with a 5-7-5 tricyclic skeleton, six chiral centers, and four exo-olefins. This natural product has numerous attractive biological activities including the inhibition of NF-κB activation, antihepatitis C activity, and antitrypanosomal activity. In this study, the first total synthesis of cynaropicrin was achieved starting from (S)-α-pinene. The synthesis involved a stereoselective Favorskii rearrangement and an indium-promoted diastereoselective Barbier reaction.

20.
J Appl Toxicol ; 41(6): 987-992, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-32996631

RESUMO

The widespread use of tris(1,3-dichloro-2-propyl) phosphate (TDCIPP) as a flame retardant has led to its release to the environment. Thus, the toxicological effects of TDCIPP on humans and animals are of importance. For better understanding of its potential toxicities, TDCIPP (250, 500, or 650 mg/kg/day) or vehicle control was administrated orally to adult male Wistar-Imamichi rats for 7 days. After the final administration of compounds, organ weights, histopathology, blood biochemistry, and hematology were examined. Hepatic toxicity was observed at doses ≥ 500 mg/kg/day of TDCIPP, and renal toxicity was observed at 650 mg/kg/day. The anti-androgenic activity of TDCIPP was previously confirmed in vitro and in vivo, but weights of epididymis, an androgen-dependent organ, were not affected by TDCIPP treatment in adults. Serum alkaline phosphatase activity was significantly decreased in all TDCIPP-treated rats independent of dose. Hemoglobin concentration, hematocrit, red blood cell count, and reticulocyte count were decreased in all TDCIPP-treated rats, but mean corpuscular volume, total iron-binding capacity, and serum iron were normal, suggesting that renal anemia was caused by TDCIPP. Together with previous reports on effects of anti-androgenic substances on red blood cell indices, anemia caused by TDCIPP could be due to its anti-androgenic activity. These considerations will contribute to further assessment of the toxicity of the compound.


Assuntos
Retardadores de Chama/toxicidade , Organofosfatos/toxicidade , Animais , Apoptose/efeitos dos fármacos , Masculino , Compostos Organofosforados/farmacologia , Fosfatos , Ratos , Ratos Wistar
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA