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1.
Cell ; 185(23): 4394-4408.e10, 2022 11 10.
Artigo em Inglês | MEDLINE | ID: mdl-36368307

RESUMO

Living organisms are constantly exposed to DNA damage, and optimal repair is therefore crucial. A characteristic hallmark of the response is the formation of sub-compartments around the site of damage, known as foci. Following multiple DNA breaks, the transcription factor p53 exhibits oscillations in its nuclear concentration, but how this dynamics can affect the repair remains unknown. Here, we formulate a theory for foci formation through droplet condensation and discover how oscillations in p53, with its specific periodicity and amplitude, optimize the repair process by preventing Ostwald ripening and distributing protein material in space and time. Based on the theory predictions, we reveal experimentally that the oscillatory dynamics of p53 does enhance the repair efficiency. These results connect the dynamical signaling of p53 with the microscopic repair process and create a new paradigm for the interplay of complex dynamics and phase transitions in biology.


Assuntos
Proteínas Proto-Oncogênicas c-mdm2 , Proteína Supressora de Tumor p53 , Proteína Supressora de Tumor p53/metabolismo , Proteínas Proto-Oncogênicas c-mdm2/genética , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Reparo do DNA , Dano ao DNA , Transdução de Sinais/fisiologia
2.
Eur Radiol ; 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38750169

RESUMO

OBJECTIVES: To evaluate signal enhancement ratio (SER) for tissue characterization and prognosis stratification in pancreatic adenocarcinoma (PDAC), with quantitative histopathological analysis (QHA) as the reference standard. METHODS: This retrospective study included 277 PDAC patients who underwent multi-phase contrast-enhanced (CE) MRI and whole-slide imaging (WSI) from three centers (2015-2021). SER is defined as (SIlt - SIpre)/(SIea - SIpre), where SIpre, SIea, and SIlt represent the signal intensity of the tumor in pre-contrast, early-, and late post-contrast images, respectively. Deep-learning algorithms were implemented to quantify the stroma, epithelium, and lumen of PDAC on WSIs. Correlation, regression, and Bland-Altman analyses were utilized to investigate the associations between SER and QHA. The prognostic significance of SER on overall survival (OS) was evaluated using Cox regression analysis and Kaplan-Meier curves. RESULTS: The internal dataset comprised 159 patients, which was further divided into training, validation, and internal test datasets (n = 60, 41, and 58, respectively). Sixty-five and 53 patients were included in two external test datasets. Excluding lumen, SER demonstrated significant correlations with stroma (r = 0.29-0.74, all p < 0.001) and epithelium (r = -0.23 to -0.71, all p < 0.001) across a wide post-injection time window (range, 25-300 s). Bland-Altman analysis revealed a small bias between SER and QHA for quantifying stroma/epithelium in individual training, validation (all within ± 2%), and three test datasets (all within ± 4%). Moreover, SER-predicted low stromal proportion was independently associated with worse OS (HR = 1.84 (1.17-2.91), p = 0.009) in training and validation datasets, which remained significant across three combined test datasets (HR = 1.73 (1.25-2.41), p = 0.001). CONCLUSION: SER of multi-phase CE-MRI allows for tissue characterization and prognosis stratification in PDAC. CLINICAL RELEVANCE STATEMENT: The signal enhancement ratio of multi-phase CE-MRI can serve as a novel imaging biomarker for characterizing tissue composition and holds the potential for improving patient stratification and therapy in PDAC. KEY POINTS: Imaging biomarkers are needed to better characterize tumor tissue in pancreatic adenocarcinoma. Signal enhancement ratio (SER)-predicted stromal/epithelial proportion showed good agreement with histopathology measurements across three distinct centers. Signal enhancement ratio (SER)-predicted stromal proportion was demonstrated to be an independent prognostic factor for OS in PDAC.

3.
J Org Chem ; 89(5): 3652-3656, 2024 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-38353480

RESUMO

An efficient synthetic approach was developed and applied to the syntheses of four linear biosynthetic C25-precursors of leucosceptroids. The synthesis features a Julia-Kocienski olefination and a late-stage bioinspired photo-oxidation as key steps. The immunosuppressive effects of all synthetic compounds on mouse T cells and macrophage RAW264.7 were determined.


Assuntos
Estrutura Molecular , Animais , Camundongos , Oxirredução
4.
Org Biomol Chem ; 22(15): 3019-3024, 2024 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-38530279

RESUMO

An unusual pyridine-containing sesterterpenoid, leucosceptrodine (1), and five new nor-leucosceptrane sesterterpenoids, including bisnor- (C23, 2), tetranor- (C21, 3) and pentanor- (C20, 4-6) skeletons, were isolated from the leaves of Tibetan Leucosceptrum canum. Their structures including their absolute configurations were determined by extensive spectroscopic analyses and quantum chemical calculations. A single crystal of one epimer (5) was crystallized from a pair of inseparable epimers, and its structure including its absolute configuration was determined by X-ray crystallographic analysis. The immunosuppressive activities of compounds 1-4 with different potencies were evaluated by inhibiting the secretion of cytokines TNF-α and IL-6 in LPS-induced RAW264.7 macrophages.


Assuntos
Lamiaceae , Sesterterpenos , Sesterterpenos/química , Tibet , Lamiaceae/química , Cristalografia por Raios X , Piridinas/farmacologia , Estrutura Molecular
5.
J Nat Prod ; 87(4): 1103-1115, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38600744

RESUMO

Twelve new alkaloids, scolopenolines A-L (1-7, 9-11, 13, 14), along with six known analogues, were isolated from Scolopendra subspinipes mutilans, identified by analysis of spectroscopic data and quantum chemical and computational methods. Scolopenoline A (1), a unique guanidyl-containing C14 quinoline alkaloid, features a 6/6/5 ring backbone. Scolopenoline B (2) is a novel sulfonyl-containing heterodimer comprising quinoline and tyramine moieties. Scolopenoline G (7) presents a rare C12 quinoline skeleton with a 6/6/5 ring system. Alkaloids 1, 8, 10, and 15-18 display anti-inflammatory activity, while 10 and 16-18 also exhibit anti-renal-fibrosis activity. Drug affinity responsive target stability and RNA-interference assays show that Lamp2 might be a potentially important target protein of 16 for anti-renal-fibrosis activity.


Assuntos
Alcaloides , Animais Peçonhentos , Quilópodes , Animais , Alcaloides/farmacologia , Alcaloides/química , Alcaloides/isolamento & purificação , Estrutura Molecular , Artrópodes/química , Fibrose/tratamento farmacológico , Rim/efeitos dos fármacos , Quinolinas/farmacologia , Quinolinas/química , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Humanos
6.
Phytochem Anal ; 35(4): 621-633, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38191170

RESUMO

INTRODUCTION: Steroidal saponins characterised by intricate chemical structures are the main active components of a well-known traditional Chinese medicine (TCM) Rhizoma Paridis. The metabolic profiles of steroidal saponins in vivo remain largely unexplored, despite their renowned antitumor, immunostimulating, and haemostatic activity. OBJECTIVE: To perform a comprehensive analysis of the chemical constituents of Rhizoma Paridis total saponins (RPTS) and their metabolites in rats after oral administration. METHOD: The chemical constituents of RPTS and their metabolites were analysed using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS). RESULTS: A reliable UPLC-Q-TOF-MS/MS method was established, and a total of 142 compounds were identified in RPTS. Specifically, diosgenin-type saponins showed the diagnostic ions at m/z 415.32, 397.31, 283.25, 271.21, and 253.20, whereas pennogenin-type saponins exhibited the diagnostic ions at m/z 413.31, 395.30, and 251.20. Based on the characteristic fragments and standard substances, 15 specific metabolites were further identified in the faeces, urine, plasma, and bile of rats. The metabolic pathways of RPTS, including phase I reactions (de-glycosylation and oxidation) and phase II reactions (glucuronidation), were explored and summarised, and the enrichment of metabolites was characterised by multivariate statistical analysis. CONCLUSION: The intricate RPTS could be transformed into relatively simple metabolites in rats through de-glycosylation, which provides a reference for further metabolic studies and screening of active ingredients for TCM.


Assuntos
Ratos Sprague-Dawley , Saponinas , Espectrometria de Massas em Tandem , Animais , Saponinas/análise , Saponinas/química , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida de Alta Pressão/métodos , Masculino , Ratos , Rizoma/química , Medicamentos de Ervas Chinesas/química , Esteroides/análise
7.
J Asian Nat Prod Res ; 26(1): 78-90, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38069835

RESUMO

Phytochemical investigation on the aerial parts of Salvia deserta led to the isolation of eight new pentacyclic triterpenoids including three oleanane- (1 - 3) and five ursane-type (4 - 8) triterpenoids, whose structures were elucidated based on extensive spectroscopic analysis and quantum chemical calculation. Weak immunosuppressive potency was observed for compounds 1, 2, and 4 - 8 via inhibiting the secretion of cytokines TNF-α and IL-6 in LPS-induced macrophages RAW264.7 at 20 µM. In addition, compounds 1, 2, and 4 - 6 exhibited moderate protective activity on t-BHP-induced oxidative injury in HepG2 cells.


Assuntos
Salvia , Triterpenos , Triterpenos/farmacologia , Triterpenos/química , Salvia/química , Estrutura Molecular , Citocinas , Componentes Aéreos da Planta/química
8.
Zhongguo Dang Dai Er Ke Za Zhi ; 26(1): 62-66, 2024 Jan 15.
Artigo em Zh | MEDLINE | ID: mdl-38269461

RESUMO

OBJECTIVES: To investigate the risk factors for diabetic ketoacidosis (DKA) in children/adolescents with type 1 diabetes mellitus (T1DM) and to establish a model for predicting the risk of DKA. METHODS: A retrospective analysis was performed on 217 children/adolescents with T1DM who were admitted to General Hospital of Ningxia Medical University from January 2018 to December 2021. Among the 217 children/adolescents,169 cases with DKA were included as the DKA group and 48 cases without DKA were included as the non-DKA group. The risk factors for DKA in the children/adolescents with T1DM were analyzed, and a nomogram model was established for predicting the risk of DKA in children/adolescents with T1DM. RESULTS: For the 217 children/adolescents with T1DM, the incidence rate of DKA was 77.9% (169/217). The multivariate logistic regression analysis showed that high levels of random blood glucose, hemoglobin A1c (HbA1c), blood ketone body, and triglyceride on admission were closely associated with the development of DKA in the children/adolescents with T1DM (OR=1.156, 3.2031015, 20.131, and 9.519 respectively; P<0.05). The nomogram prediction model had a C-statistic of 0.95, with a mean absolute error of 0.004 between the risk of DKA predicted by the nomogram model and the actual risk of DKA, indicating that the model had a good overall prediction ability. CONCLUSIONS: High levels of random blood glucose, HbA1c, blood ketone body, and triglyceride on admission are closely associated with the development of DKA in children/adolescents with T1DM, and targeted intervention measures should be developed to reduce the risk of DKA.


Assuntos
Diabetes Mellitus Tipo 1 , Cetose , Criança , Adolescente , Humanos , Diabetes Mellitus Tipo 1/complicações , Glicemia , Hemoglobinas Glicadas , Estudos Retrospectivos , Fatores de Risco , Corpos Cetônicos , Triglicerídeos
9.
Radiology ; 307(4): e222729, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37097141

RESUMO

Background Prediction of microvascular invasion (MVI) may help determine treatment strategies for hepatocellular carcinoma (HCC). Purpose To develop a radiomics approach for predicting MVI status based on preoperative multiphase CT images and to identify MVI-associated differentially expressed genes. Materials and Methods Patients with pathologically proven HCC from May 2012 to September 2020 were retrospectively included from four medical centers. Radiomics features were extracted from tumors and peritumor regions on preoperative registration or subtraction CT images. In the training set, these features were used to build five radiomics models via logistic regression after feature reduction. The models were tested using internal and external test sets against a pathologic reference standard to calculate area under the receiver operating characteristic curve (AUC). The optimal AUC radiomics model and clinical-radiologic characteristics were combined to build the hybrid model. The log-rank test was used in the outcome cohort (Kunming center) to analyze early recurrence-free survival and overall survival based on high versus low model-derived score. RNA sequencing data from The Cancer Image Archive were used for gene expression analysis. Results A total of 773 patients (median age, 59 years; IQR, 49-64 years; 633 men) were divided into the training set (n = 334), internal test set (n = 142), external test set (n = 141), outcome cohort (n = 121), and RNA sequencing analysis set (n = 35). The AUCs from the radiomics and hybrid models, respectively, were 0.76 and 0.86 for the internal test set and 0.72 and 0.84 for the external test set. Early recurrence-free survival (P < .01) and overall survival (P < .007) can be categorized using the hybrid model. Differentially expressed genes in patients with findings positive for MVI were involved in glucose metabolism. Conclusion The hybrid model showed the best performance in prediction of MVI. © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Summers in this issue.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Masculino , Humanos , Pessoa de Meia-Idade , Carcinoma Hepatocelular/diagnóstico por imagem , Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/genética , Estudos Retrospectivos , Invasividade Neoplásica/patologia , Tomografia Computadorizada por Raios X/métodos
10.
Transpl Int ; 36: 11595, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37745643

RESUMO

Diagnosing acute rejection after intestinal transplantation currently heavily relies on histopathological analysis of graft biopsies. However, the invasive risks associated with ileoscopic examination and the inaccessibility for biopsy after ileostomy closure hinder real-time detection of rejection responses. Molecules comprising the intestinal barrier have been identified as physiological and molecular biomarkers for various bowel conditions and systemic diseases. To investigate the potential of barrier function-related molecules in diagnosing rejection after intestinal transplantation, plasma samples were collected longitudinally from transplant recipients. The samples were categorized into "indeterminate for rejection (IND)" and "acute rejection (AR)" groups based on clinical diagnoses at each time point. The longitudinal association between plasma levels of these barrier function-related molecules and acute rejection was analyzed using the generalized estimating equations (GEE) method. Logistic GEE models revealed that plasma levels of claudin-3, occludin, sIgA, and zonulin were independent variables correlated with the clinical diagnosis of acute rejection. The subsequent prediction model demonstrated moderate ability in discriminating between IND and AR samples, with a sensitivity of 76.0%, specificity of 89.2%, and accuracy of 84.6%. In conclusion, monitoring plasma levels of claudin-3, occludin, sIgA, and zonulin shows great potential in aiding the diagnosis of acute rejection after intestinal transplantation.


Assuntos
Rejeição de Enxerto , Intestinos , Humanos , Claudina-3 , Ocludina , Rejeição de Enxerto/diagnóstico , Imunoglobulina A Secretora
11.
J Nat Prod ; 86(11): 2468-2473, 2023 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-37939268

RESUMO

Three unusual sesterterpenoids featuring unprecedented rearranged colquhounane (C25) and tetranorcolquhounane (C21) frameworks, colquhounoids E (1) and F (3) and norcolquhounoid F (2), were isolated from a Lamiaceae medicinal plant Colquhounia coccinea var. mollis. Their structures were elucidated by spectroscopic analysis and quantum chemical calculations. A biomimetic inspired regioselective cyclopropane cleavage was achieved under acidic conditions. The immunosuppressive activities of these new sesterterpenoids were also evaluated.


Assuntos
Lamiaceae , Plantas Medicinais , Análise Espectral , Lamiaceae/química , Estrutura Molecular
12.
Mol Ther ; 30(2): 509-518, 2022 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-34763085

RESUMO

Aromatic L-amino acid decarboxylase deficiency results in decreased neurotransmitter levels and severe motor dysfunction. Twenty-six patients without head control received bilateral intraputaminal infusions of a recombinant adeno-associated virus type 2 vector containing the human aromatic L-amino acid decarboxylase gene (eladocagene exuparvovec) and have completed 1-year evaluations. Rapid improvements in motor and cognitive function occurred within 12 months after gene therapy and were sustained during follow-up for >5 years. An increase in dopamine production was demonstrated by positron emission tomography and neurotransmitter analysis. Patient symptoms (mood, sweating, temperature, and oculogyric crises), patient growth, and patient caretaker quality of life improved. Although improvements were observed in all treated participants, younger age was associated with greater improvement. There were no treatment-associated brain injuries, and most adverse events were related to underlying disease. Post-surgery complications such as cerebrospinal fluid leakage were managed with standard of care. Most patients experienced mild to moderate dyskinesia that resolved in a few months. These observations suggest that eladocagene exuparvovec treatment for aromatic L-amino acid decarboxylase deficiency provides durable and meaningful benefits with a favorable safety profile.


Assuntos
Erros Inatos do Metabolismo dos Aminoácidos , Qualidade de Vida , Erros Inatos do Metabolismo dos Aminoácidos/diagnóstico , Erros Inatos do Metabolismo dos Aminoácidos/genética , Erros Inatos do Metabolismo dos Aminoácidos/terapia , Descarboxilases de Aminoácido-L-Aromático/líquido cefalorraquidiano , Descarboxilases de Aminoácido-L-Aromático/deficiência , Descarboxilases de Aminoácido-L-Aromático/genética , Dopamina , Terapia Genética/efeitos adversos , Humanos
13.
Am J Hum Biol ; 35(9): e23913, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37200487

RESUMO

BACKGROUND: This article aimed to study the adjustment and adaptation of resting systolic blood pressure (SBP), diastolic blood pressure (DPB), oxygen saturation (SpO2 ), hemoglobin concentration ([Hb]), and heart rate (HR) in low-altitude migrants during a 1-year stay at high altitude. MATERIALS AND METHODS: Our study enrolled 35 young migrants who were exposed to a hypoxia environment at 5380 m altitude on the Qinghai Tibetan Plateau between June 21, 2017, and June 16, 2018. We set 14-time points (the 1st-10th, 20th, 30th, 180th, and 360th day after arriving at 5380 m) for obtaining the measurements of resting SBP, DBP, HR, SpO2, and [Hb] and compared them with the control values recorded prior to migration. Variables with continuous data were summarized as means (SD). One-way repeated measures ANOVA without assuming sphericity was carried out to test whether the mean values (SBP, DBP, HR, SpO2 , and [Hb]) on different days were different significantly. Furthermore, Dunnett's multiple comparisons test was carried out to determine the time points whose values were significantly different from the control values. RESULTS: SBP and DBP were continually increasing within d1-3 and peaked on the 3rd day, then steadily declined from d3 to d30. SBP fell back to the control values on d10 (p > 0.05), and DBP fell back to the control values on d20 (p > 0.05). A significant decline occurred on d180 (p < 0.05). Both SBP and DBP were lower than the control values on d180 (p < 0.05), and this trend was maintained to d360. There were similar characteristics of HR and BP in the time course at HA. HR on d1-3 was increasing (p < 0.05) compared to the control values, after which it fell back to the control values on d180 (p > 0.05), and this trend was maintained to d360. SpO2 was the lowest on d1 and lower than the control value throughout the study at HA (p < 0.05). [Hb] increased after long-term exposure (180 and 360 days) to HA (p < 0.05). CONCLUSIONS: Our study continuously monitored lowlanders at 5380 m in Tibet, and is perhaps the only longitudinal study of migrants conducted at an altitude above 5000 m during a 1-year period. Our study provides new information on the adjustment and adaptation of [Hb], SpO2 , SBP, DBP, and HR in high-altitude plateau migrants during a 360-day stay at an altitude of 5380 m.


Assuntos
Altitude , Saturação de Oxigênio , Humanos , Pressão Sanguínea , Frequência Cardíaca/fisiologia , Estudos Longitudinais , Hemoglobinas , Oxigênio
14.
Clin Infect Dis ; 75(1): e1054-e1062, 2022 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-34788811

RESUMO

BACKGROUND: To combat the coronavirus disease 2019 (COVID-19) pandemic, nonpharmaceutical interventions (NPIs) were implemented worldwide, which impacted a broad spectrum of acute respiratory infections (ARIs). METHODS: Etiologically diagnostic data from 142 559 cases with ARIs, who were tested for 8 viral pathogens (influenza virus [IFV], respiratory syncytial virus [RSV], human parainfluenza virus [HPIV], human adenovirus [HAdV], human metapneumovirus [HMPV], human coronavirus [HCoV], human bocavirus [HBoV], and human rhinovirus [HRV]) between 2012 and 2021, were analyzed to assess the changes in respiratory infections in China during the first COVID-19 pandemic year compared with pre-pandemic years. RESULTS: Test-positive rates of all respiratory viruses decreased during 2020, compared to the average levels during 2012-2019, with changes ranging from -17.2% for RSV to -87.6% for IFV. Sharp decreases mostly occurred between February and August when massive NPIs remained active, although HRV rebounded to the historical level during the summer. While IFV and HMPV were consistently suppressed year-round, RSV, HPIV, HCoV, HRV, and HBoV resurged and went beyond historical levels during September 2020-January 2021, after NPIs were largely relaxed and schools reopened. Resurgence was more prominent among children <18 years and in northern China. These observations remain valid after accounting for seasonality and long-term trend of each virus. CONCLUSIONS: Activities of respiratory viral infections were reduced substantially in the early phases of the COVID-19 pandemic, and massive NPIs were likely the main driver. Lifting of NPIs can lead to resurgence of viral infections, particularly in children.


Assuntos
COVID-19 , Bocavirus Humano , Metapneumovirus , Orthomyxoviridae , Vírus Sincicial Respiratório Humano , Infecções Respiratórias , Viroses , Vírus , COVID-19/epidemiologia , Criança , Humanos , Pandemias , Vírus da Parainfluenza 1 Humana
15.
Neurobiol Dis ; 175: 105899, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36265768

RESUMO

Deep brain stimulation (DBS) conventionally target at basal ganglia or thalamic structures, modulating nodal points in the cortico-basal ganglia circuit, in order to effectively treat various movement disorders, including Parkinson's disease, tremor and dystonia (especially mobile type dystonia). However, there are still some other movement disorders, such as dystonia (especially fixed type dystonia), ataxia and freezing of gait, which are not responding well to the current DBS therapy. Cerebellum, similar to basal ganglia, also plays a critical role in the pathophysiology of movement disorders. Deep cerebellar structures, such as dentate nucleus or superior cerebellar peduncle, are noticed for their potential role as treatment targets in movement disorders in recent years. With increasing evidences of animal DBS experiments, recent clinical human subject studies reported that some movement disorders patients not responding to DBS with conventional targets, may benefit significantly from cerebellar DBS. These pioneer study results are invaluable for understanding the clinical use of cerebellar DBS for treatment of movement disorders. We review the recent data of cerebellar DBS performed by different groups and summarize the indications, surgical targets, programming details and outcomes in these clinical reports. We then synthesize the current pathophysiological study of cerebellum on different movement disorders and discuss the potential mechanism of action of cerebellar DBS. In addition to basal ganglia, it is important to study new DBS targets in the cerebellum for more comprehensive treatment of movement disorders.


Assuntos
Estimulação Encefálica Profunda , Distonia , Distúrbios Distônicos , Transtornos Neurológicos da Marcha , Transtornos dos Movimentos , Doença de Parkinson , Animais , Humanos , Estimulação Encefálica Profunda/métodos , Transtornos Neurológicos da Marcha/terapia , Transtornos dos Movimentos/terapia , Cerebelo , Distúrbios Distônicos/terapia
16.
Anal Chem ; 94(10): 4455-4462, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35229593

RESUMO

A novel simple electrothermal desolvation-enhanced dielectric barrier discharge plasma-induced vapor generation (ETD-DBD-PIVG) method has been developed for sensitive Sb determination by atomic fluorescence spectrometry (AFS). In our proposed ETD-DBD-PIVG, 20 µL sample solution was dried first; then, the resulting solution residue was directly converted into molecular volatile species efficiently through the interactions with hydrogen-doped DBD plasma; and finally, it was transported to AFS for detection. It was found that the desolvation process could greatly enhance Sb vapor generation, and the Sb fluorescence signal intensity is almost independent of its speciation, where comparable sensitivity is achieved for Sb(III) and Sb(V), enabling efficient total Sb detection without pre-reduction. Influencing parameters were evaluated in detail, including heating time, discharge gap, solution pH, and flow rates of argon and hydrogen, as well as coexisting ion interference. Under optimized conditions, the limit of detection was calculated as 0.86 µg L-1 (17.2 pg) for Sb. The accuracy of the proposed method was validated by the analysis of certified reference materials of simulated natural water samples and several river water samples. Compared with conventional hydride generation, the new ETD-DBD-PIVG offers an alternative green vapor generation technique with several advantages: (1) it eliminates the use of a sample flow system (e.g., no use of any syringe or peristaltic pump); instead, 20 µL of a sample is directly pipetted onto the glass plate for analysis; (2) it greatly simplifies the sample pretreatment steps as no pre-reduction process is needed; (3) it is sensitive and suitable for volume-limited sample analysis: efficient Sb vapor generation without chemical reducing reagents in ETD-DBD-PIVG enables Sb detection with an absolute limit at the picogram level. All the results demonstrate that the proposed method provides a simple, green, and sensitive method for Sb determination and it can also be extended to other elements such as Cd and As.


Assuntos
Antimônio , Água Doce , Antimônio/análise , Água Doce/análise , Hidrogênio , Espectrometria de Fluorescência/métodos , Água
17.
Anal Chem ; 94(2): 1397-1405, 2022 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-34962777

RESUMO

The sensing technologies for monitoring molecular analytes in biological fluids with high frequency and in real time could enable a broad range of applications in personalized healthcare and clinical diagnosis. However, due to the limited dynamic range (less than 81-fold), real-time analysis of biomolecular concentration varying over multiple orders of magnitude is a severe challenge faced by this class of analytical platforms. For the first time, we describe here that temperature-modulated electrochemical aptamer-based sensors with a dynamically adjustable calibration-free detection window could enable continuous, real-time, and accurate response for the several-hundredfold target concentration changes in unprocessed actual samples. Specifically, we could regulate the electrode surface temperature of sensors to obtain the corresponding dynamic range because of the temperature-dependent affinity variations. This temperature modulation method relies on an alternate hot and cold electrode reported by our group, whose surface could actively be heated and cooled without the need for altering ambient temperature, thus likewise applying for the flowing system. We then performed dual-frequency calibration-free measurements at different interface temperatures, thus achieving an extended detection window from 25 to 2500 µM for procaine in undiluted urine, 1-500 µM for adenosine triphosphate, and 5-2000 µM for adenosine in undiluted serum. The resulting sensor architecture could drastically expand the real-time response range accessible to these continuous, reagent-less biosensors.


Assuntos
Aptâmeros de Nucleotídeos , Técnicas Biossensoriais , Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Técnicas Eletroquímicas/métodos , Eletrodos , Temperatura
18.
Mol Syst Biol ; 17(10): e10480, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34612597

RESUMO

Cells metabolize nutrients through a complex metabolic and signaling network that governs redox homeostasis. At the core of this, redox regulatory network is a mutually inhibitory relationship between reduced glutathione and reactive oxygen species (ROS)-two opposing metabolites that are linked to upstream nutrient metabolic pathways (glucose, cysteine, and glutamine) and downstream feedback loops of signaling pathways (calcium and NADPH oxidase). We developed a nutrient-redox model of human cells to understand system-level properties of this network. Combining in silico modeling and ROS measurements in individual cells, we show that ROS dynamics follow a switch-like, all-or-none response upon glucose deprivation at a threshold that is approximately two orders of magnitude lower than its physiological concentration. We also confirm that this ROS switch can be irreversible and exhibits hysteresis, a hallmark of bistability. Our findings evidence that bistability modulates redox homeostasis in human cells and provide a general framework for quantitative investigations of redox regulation in humans.


Assuntos
Glutationa , Transdução de Sinais , Glutationa/metabolismo , Homeostase , Humanos , Oxirredução , Espécies Reativas de Oxigênio
19.
Rheumatology (Oxford) ; 61(5): 1849-1856, 2022 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-34534283

RESUMO

OBJECTIVES: RA damages the joints and increases the risks of total knee replacement (TKR) and total hip replacement (THR). However, the benefits of biologics in preventing TKR or THR remain unclear. METHODS: This retrospective nationwide study used the 2000-2013 claims-based National Health Insurance dataset. Biologics are reimbursed for refractory cases. The risks of TKR and THR in the biologic cohort were compared with those of an age- and sex-matched csDMARD cohort. A multivariate Cox regression model was used to investigate the benefits of bDMARDs for TKR and THR. RESULTS: TKR was performed in 5979 biologic cases and 11 958 matched controls, of which 249 (4.16%) and 871 (7.28%) cases received TKR, respectively. THR was performed in 6245 biologic cases and 12 490 matched controls, of which 159 (2.55%) and 516 (4.13%) cases had THR, respectively. The biologic cohort had significantly lower incidence rates of TKR (11.73 vs 16.33/1000 person-years, P < 0.001) and THR (7.09 vs 9.16/1000 person-years, P < 0.001). After adjustment for confounding factors, the regular bDMARD subgroup (average dose >0.95 defined daily dose/day) had significantly lower risks of TKR (aHR: 0.55, 95% CI: 0.38, 0.81) and THR (aHR: 0.63, 95% CI: 0.40, 0.98). Those without MTX use, with steroid use, with biologic switch, and overlapping antiphospholipid syndrome had significantly higher risks of TKR and THR. CONCLUSIONS: Compared with the csDMARD cohort, the risks of TKR and THR in the bDMARD cohort were the same as those in the low-to-moderate dose subgroups and significantly lower in those with regular bDMARD use.


Assuntos
Artrite Reumatoide , Artroplastia de Quadril , Artroplastia do Joelho , Produtos Biológicos , Artrite Reumatoide/tratamento farmacológico , Artrite Reumatoide/cirurgia , Produtos Biológicos/uso terapêutico , Humanos , Estudos Retrospectivos
20.
Eur Radiol ; 32(10): 6943-6952, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35471667

RESUMO

OBJECTIVES: We aimed to investigate the additional significance of cerebral small vessel disease (SVD) beyond collaterals in determining the clinical outcome after acute ischemic stroke (AIS). METHODS: We retrospectively reviewed large vessel-involved stroke patients who had baseline CTA within 24 h after symptom onset and had an MRI scan 5 days after admission from October 1, 2018, to October 31, 2021. Collaterals and SVD markers (including atrophy, leukoaraiosis, lacunes, and perivascular space) were graded on CT angiography and MR images, respectively. Modified Rankin Scale (mRS) score at 90 days was recorded, and mRS ≤ 2 was regarded as a good clinical outcome. The associations between SVD markers, collaterals, and mRS were analyzed using logistic and causal mediation regression. RESULTS: We finally enrolled 119 patients (70 ± 13 years). The multivariable regression showed atrophy (evidence: OR 0.05 [95% CI 0.01-0.31], p = 0.002; severe: OR 0.08 [95% CI 0.01-0.44], p = 0.007) and evidence of lacune (OR 0.30 [95% CI 0.08-0.96], p = 0.049) were associated with poor clinical outcomes after correcting covariables. Collaterals mediated 25.74% of the effect of atrophy on poor clinical outcomes (p < 0.001), while lacune impacted clinical outcomes without collaterals' mediation effect (p = 0.54). The classification model with atrophy and lacune had a significantly higher AUC than without markers to distinguish good and poor outcomes (p = 0.036). CONCLUSIONS: Beyond collaterals, brain frailty, specifically assessed by atrophy and lacune, was essential in evaluating stroke patients and could additionally improve the stroke outcome prediction. KEY POINTS: • Beyond collaterals, brain frailty, specifically assessed by brain atrophy and lacune, was still an independent risk factor of unfavorable clinical outcomes after AIS. • Adding brain atrophy and lacune into the model has an extra benefit in predicting stroke outcomes. • The effect of atrophy on stroke outcomes was proportionally mediated through collaterals, but about three-quarters of the effect of brain atrophy and the total effect of lacune directly impacted stroke outcomes without a mediation effect of collaterals.


Assuntos
Isquemia Encefálica , Fragilidade , AVC Isquêmico , Acidente Vascular Cerebral , Atrofia , Encéfalo/diagnóstico por imagem , Isquemia Encefálica/complicações , Isquemia Encefálica/diagnóstico por imagem , Humanos , AVC Isquêmico/diagnóstico por imagem , Estudos Retrospectivos , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/etiologia , Resultado do Tratamento
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