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1.
J Neurooncol ; 166(1): 167-174, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38133789

RESUMO

PURPOSE: This paper presents a deep learning model for use in the automated segmentation of metastatic brain tumors and associated perilesional edema. METHODS: The model was trained using Gamma Knife surgical data (90 MRI sets from 46 patients), including the initial treatment plan and follow-up images (T1-weighted contrast-enhanced (T1cWI) and T2-weighted images (T2WI)) manually annotated by neurosurgeons to indicate the target tumor and edema regions. A mask region-based convolutional neural network was used to extract brain parenchyma, after which the DeepMedic 3D convolutional neural network was in the segmentation of tumors and edemas. RESULTS: Five-fold cross-validation demonstrated the efficacy of the brain parenchyma extraction model, achieving a Dice similarity coefficient of 96.4%. The segmentation models used for metastatic tumors and brain edema achieved Dice similarity coefficients of 71.6% and 85.1%, respectively. This study also presents an intuitive graphical user interface to facilitate the use of these models in clinical analysis. CONCLUSION: This paper introduces a deep learning model for the automated segmentation and quantification of brain metastatic tumors and perilesional edema trained using only T1cWI and T2WI. This technique could facilitate further research on metastatic tumors and perilesional edema as well as other intracranial lesions.


Assuntos
Neoplasias Encefálicas , Aprendizado Profundo , Humanos , Processamento de Imagem Assistida por Computador/métodos , Redes Neurais de Computação , Neoplasias Encefálicas/complicações , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/patologia , Imageamento por Ressonância Magnética/métodos , Edema
2.
Org Biomol Chem ; 22(27): 5552-5560, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38904217

RESUMO

The arene cyclopropanation between diazo compounds and benzene is well known to produce a tautomeric mixture of norcaradiene and cycloheptatriene in favour of the latter species. Nevertheless, previous studies have suggested that the initially formed norcaradiene can be stabilized by a C-7 cyano group with prevention of its 6π-electrocyclic ring opening. According to this feature, a synthetic route to functionalized cyclohexadienes has been designed using α-cyanodiazoacetates and α-diazo-ß-ketonitriles as the starting materials, respectively. The Rh2(esp)2-catalyzed arene cyclopropanation of α-cyanodiazoacetates in benzene afforded the expected 7-alkoxycarbonyl-7-cyanonorcaradienes as isolable compounds, which then served as templates for the second cyclopropanation with ethyl diazoacetate or α-cyanodiazocarbonyls to enable the formation of bis(cyclopropanated) adducts. Their subsequent treatment with SmI2 triggered a double ring-opening process, allowing for the generation of 1,4- and/or 1,3-cyclohexadienes as either regio- or diastereomeric mixtures. On the other hand, the norcaradienes generated from phenyl- or methyl-substituted α-diazo-ß-ketonitriles were found to undergo an in situ rearrangement to yield dihydrobenzofurans that could be converted to benzofuran derivatives by DDQ oxidation.

3.
J Vet Pharmacol Ther ; 47(1): 36-47, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37593974

RESUMO

Toltrazuril (TZR) is currently the only registered chemotherapeutic drug in the European Union for the treatment of Cystoisospora suis. This study investigated the comparative pharmacokinetics and tissue concentration-time profiles of TZR and its active metabolite, toltrazuril sulfone (TZR-SO2 ), after oral (per os, p.o.) and intramuscular (i.m.) administration to suckling piglets. Following a single administration of TZR orally at 50 mg/piglet or intramuscularly at 45 mg/piglet, higher concentrations of TZR and TZR-SO2 were observed in all three investigated tissues after p.o. administration. The mean TZR concentration in serum peaked at 14 µg/mL (34.03 h) and 5.36 µg/mL (120 h), while TZR-SO2 peaked at 14.12 µg/mL (246 h) and 9.92 µg/mL (330 h) after p.o. and i.m. administration, respectively. TZR was undetectable in the liver after p.o. administration (18 days) and in the jejunum (24 days) after i.m. injection, while TZR-SO2 was still detectable in all three tissues after 36 days regardless of administration routes. This study showed that p.o. formulation exhibited faster absorption and higher serum/tissue TZR/TZR-SO2 concentrations than i.m. formulation. Both formulations generated sufficient therapeutic concentrations in the serum and jejunum, and sustained enough time to protect against Cystoisospora suis infection in the piglets.


Assuntos
Coccidiostáticos , Animais , Suínos , Administração Oral , Triazinas , Sulfonas , Injeções Intramusculares/veterinária
4.
J Virol ; 96(1): e0137221, 2022 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-34643430

RESUMO

Coronaviral papain-like proteases (PLpros) are essential enzymes that mediate not only the proteolytic processes of viral polyproteins during virus replication but also the deubiquitination and deISGylation of cellular proteins that attenuate host innate immune responses. Therefore, PLpros are attractive targets for antiviral drug development. Here, we report the crystal structure of papain-like protease 2 (PLP2) of porcine epidemic diarrhea virus (PEDV) in complex with ubiquitin (Ub). The X-ray structural analyses reveal that PEDV PLP2 interacts with the Ub substrate mainly through the Ub core region and C-terminal tail. Mutations of Ub-interacting residues resulted in a moderately or completely abolished deubiquitinylating function of PEDV PLP2. In addition, our analyses also indicate that 2-residue-extended blocking loop 2 at the S4 subsite contributes to the substrate selectivity and binding affinity of PEDV PLP2. Furthermore, the PEDV PLP2 Glu99 residue, conserved in alphacoronavirus PLpros, was found to govern the preference of a positively charged P4 residue of peptidyl substrates. Collectively, our data provided structure-based information for the substrate binding and selectivity of PEDV PLP2. These findings may help us gain insights into the deubiquitinating (DUB) and proteolytic functions of PEDV PLP2 from a structural perspective. IMPORTANCE Current challenges in coronaviruses (CoVs) include a comprehensive understanding of the mechanistic effects of associated enzymes, including the 3C-like and papain-like proteases. We have previously reported that the PEDV PLP2 exhibits a broader substrate preference, superior DUB function, and inferior peptidase activity. However, the structural basis for these functions remains largely unclear. Here, we show the high-resolution X-ray crystal structure of PEDV PLP2 in complex with Ub. Integrated structural and biochemical analyses revealed that (i) three Ub core-interacting residues are essential for DUB function, (ii) 2-residue-elongated blocking loop 2 regulates substrate selectivity, and (iii) a conserved glutamate residue governs the substrate specificity of PEDV PLP2. Collectively, our findings provide not only structural insights into the catalytic mechanism of PEDV PLP2 but also a model for developing antiviral strategies.


Assuntos
Proteases Semelhantes à Papaína de Coronavírus/química , Vírus da Diarreia Epidêmica Suína/química , Coronavirus/química , Coronavirus/classificação , Coronavirus/enzimologia , Proteases Semelhantes à Papaína de Coronavírus/genética , Proteases Semelhantes à Papaína de Coronavírus/metabolismo , Cristalografia por Raios X , Mutação , Vírus da Diarreia Epidêmica Suína/enzimologia , Vírus da Diarreia Epidêmica Suína/genética , Ligação Proteica , Domínios Proteicos , Relação Estrutura-Atividade , Especificidade por Substrato , Ubiquitina/química , Ubiquitina/metabolismo
5.
J Fish Dis ; 46(1): 75-84, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36179060

RESUMO

Asian seabass (Lates calcarifer) is an economically important fish in Asian and Australian markets, but few pharmacokinetic (PK) data of antimicrobial drugs in this species is available. The present study investigated the PK behaviour of florfenicol (FF) through medicated feed in Asian seabass cultured at 25°C. The serum and muscle/skin concentrations of FF and its metabolite florfenicol amine (FFA) were determined by the HPLC-FLD method and analysed by one-compartmental model. The optimal dosages were determined by pharmacokinetic-pharmacodynamic (PK-PD) approach and the linear regression analysis was used to determine the withdrawal time (WDT). The PK study following a single oral administration of 15 mg/kg FF via medicated feed revealed that the absorption half-life (t1/2Ka ), elimination half-life (t1/2K ), peak concentration (Cmax ), area under the concentration-time curve (AUC), volume of distribution (Vd/F) and clearance (CL/F) were 1.47 h, 8.07 h, 8.61 µg/ml, 146.41 h·µg/ml, 1.19 L/kg and 0.102 L/kg/h, respectively. The muscle/skin concentration-time profile was similar to that of the serum, suggesting well distribution but only a small fraction of FF was metabolized to FFA. The optimal dosage for a minimum inhibitory concentration of 2 µg/ml was calculated as 13.38 mg/kg/day. The appropriate WDT after multiple oral medications with 15 mg/kg FF once daily for 7 days was determined as 8 days. Information obtained from the current study can potentially be applied for the treatment of bacterial diseases in farming Asian seabass.


Assuntos
Doenças dos Peixes , Animais , Austrália , Testes de Sensibilidade Microbiana , Administração Oral
6.
J Vet Pharmacol Ther ; 46(2): 136-143, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36691109

RESUMO

Starvation has influence on physiology and pharmacokinetic (PK) characteristics of many drugs in land animals. However, similar PK information in fish is lacking. The current study examined the effects of starvation on fish PK, taking florfenicol (FF) in Asian seabass as an example. FF was orally administered at a single dose of 10 mg/kg into 35-day starved fish reared at 25 and 30°C and the serum FF concentration was analyzed by HPLC-FLD. At 30°C, the absorption and elimination half-lives of the starved fish were increased by 30% (from 0.44 to 0.57 h) and 55% (from 7.2 to 11.18 h), respectively. The volume of distribution, clearance, and area under the curve were changed from 1.25 to 0.71 L/kg, 0.120 to 0.044 L/kg/h, and 88 to 228 h·µg/ml, respectively. Similar starvation-induced PK changes were also observed at 25°C. The serum biochemical parameters, mainly the alanine aminotransferase, aspartate aminotransferase, and glucose levels, were significantly reduced in the starvation group. Overall, FF absorption, distribution, and elimination rates were reduced by starvation, resulting in four to five times lower optimal dosage than the non-starved fish. Drug treatment in starved fish should be treated with caution as overdosing and/or tissue residues could perceivably occur.


Assuntos
Peixes , Inanição , Tianfenicol , Animais , Tianfenicol/administração & dosagem , Tianfenicol/farmacocinética , Peixes/sangue
7.
Dysphagia ; 37(1): 37-47, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-33620562

RESUMO

Nasotracheal intubation benefits dysphonia recovery after anterior cervical spine surgery (ACSS). The aim of the present study was to investigate the effect of tracheal intubation modes on post-ACSS swallowing function and identify factors associated with deglutition on postoperative day 30 (POD 30). Adult patients were randomized to receive either nasotracheal or orotracheal intubation during surgery. A numerical rating scale (NRS) was used to assess postoperative sore throat, and the Bazaz grading system was used to assess the severity of swallowing disturbance. The primary endpoints were the effect of tracheal intubation modes on postoperative sore throat and deglutition. Thereafter, we further elucidated the predictors of swallowing disturbance on POD 30. Postoperative sore throat and swallowing disturbance did not differ between the nasotracheal and orotracheal intubation groups. A secondary dataset analysis revealed that among 108 patients with complete follow-up until POD 30, 71 (65.7%) presented complete recovery without swallowing disturbance, whereas 37 (34.3%) presented varying degrees of swallowing disturbance. Receiver operating characteristic curve analysis indicated that the NRS score for sore throat predicted a swallowing disturbance-free status on POD 30. The optimal cutoff values were ≤ 4 and ≤ 2 on PODs 1 and 2, respectively. The adjusted odds ratio (OR) for independent predictors was a sore throat NRS score of ≤ 4 on POD 1 (OR 3.2; 95% CI 1.29-7.89; P = 0.012) and score of ≤ 2 on POD 2 (OR 6.67; 95% CI 2.41-18.47; P < 0.001). Therefore, tracheal intubation mode did not affect the incidence of post-ACSS swallowing disturbance, and the severity of sore throat on PODs 1 and 2 could predict a swallowing disturbance-free status on POD 30.The trial was registered at clinicaltrials.gov (Trial No. NCT03240042, date of registration 10/17/2017).


Assuntos
Deglutição , Faringite , Adulto , Vértebras Cervicais/cirurgia , Humanos , Intubação Intratraqueal/efeitos adversos , Faringite/diagnóstico , Faringite/epidemiologia , Faringite/etiologia , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia
8.
J Biol Chem ; 295(11): 3734-3745, 2020 03 13.
Artigo em Inglês | MEDLINE | ID: mdl-32005667

RESUMO

Most of Gram-positive bacteria anchor surface proteins to the peptidoglycan cell wall by sortase, a cysteine transpeptidase that targets proteins displaying a cell wall sorting signal. Unlike other bacteria, Clostridium difficile, the major human pathogen responsible for antibiotic-associated diarrhea, has only a single functional sortase (SrtB). Sortase's vital importance in bacterial virulence has been long recognized, and C. difficile sortase B (Cd-SrtB) has become an attractive therapeutic target for managing C. difficile infection. A better understanding of the molecular activity of Cd-SrtB may help spur the development of effective agents against C. difficile infection. In this study, using site-directed mutagenesis, biochemical and biophysical tools, LC-MS/MS, and crystallographic analyses, we identified key residues essential for Cd-SrtB catalysis and substrate recognition. To the best of our knowledge, we report the first evidence that a conserved serine residue near the active site participates in the catalytic activity of Cd-SrtB and also SrtB from Staphylococcus aureus The serine residue indispensable for SrtB activity may be involved in stabilizing a thioacyl-enzyme intermediate because it is neither a nucleophilic residue nor a substrate-interacting residue, based on the LC-MS/MS data and available structural models of SrtB-substrate complexes. Furthermore, we also demonstrated that residues 163-168 located on the ß6/ß7 loop of Cd-SrtB dominate specific recognition of the peptide substrate PPKTG. The results of this work reveal key residues with roles in catalysis and substrate specificity of Cd-SrtB.


Assuntos
Aminoácidos/metabolismo , Aminoaciltransferases/química , Aminoaciltransferases/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Biocatálise , Clostridioides difficile/enzimologia , Cisteína Endopeptidases/química , Cisteína Endopeptidases/metabolismo , Sequência de Aminoácidos , Aminoaciltransferases/genética , Proteínas de Bactérias/genética , Sequência Conservada , Cristalografia por Raios X , Cisteína Endopeptidases/genética , Mutação/genética , Estrutura Secundária de Proteína , Serina/metabolismo , Relação Estrutura-Atividade , Especificidade por Substrato
9.
Nature ; 518(7537): 120-4, 2015 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-25383525

RESUMO

Biotin-dependent carboxylases are widely distributed in nature and have important functions in the metabolism of fatty acids, amino acids, carbohydrates, cholesterol and other compounds. Defective mutations in several of these enzymes have been linked to serious metabolic diseases in humans, and acetyl-CoA carboxylase is a target for drug discovery in the treatment of diabetes, cancer and other diseases. Here we report the identification and biochemical, structural and functional characterizations of a novel single-chain (120 kDa), multi-domain biotin-dependent carboxylase in bacteria. It has preference for long-chain acyl-CoA substrates, although it is also active towards short-chain and medium-chain acyl-CoAs, and we have named it long-chain acyl-CoA carboxylase. The holoenzyme is a homo-hexamer with molecular mass of 720 kDa. The 3.0 Å crystal structure of the long-chain acyl-CoA carboxylase holoenzyme from Mycobacterium avium subspecies paratuberculosis revealed an architecture that is strikingly different from those of related biotin-dependent carboxylases. In addition, the domains of each monomer have no direct contact with each other. They are instead extensively swapped in the holoenzyme, such that one cycle of catalysis involves the participation of four monomers. Functional studies in Pseudomonas aeruginosa suggest that the enzyme is involved in the utilization of selected carbon and nitrogen sources.


Assuntos
Carbono-Carbono Ligases/química , Carbono-Carbono Ligases/metabolismo , Mycobacterium avium subsp. paratuberculosis/enzimologia , Acil Coenzima A/metabolismo , Biocatálise , Biotina/metabolismo , Carbono/metabolismo , Carbono-Carbono Ligases/ultraestrutura , Microscopia Crioeletrônica , Cristalografia por Raios X , Holoenzimas/química , Holoenzimas/metabolismo , Modelos Moleculares , Nitrogênio/metabolismo , Estrutura Terciária de Proteína , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , Pseudomonas aeruginosa/enzimologia , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/metabolismo , Relação Estrutura-Atividade
10.
J Clin Lab Anal ; 34(4): e23110, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31733007

RESUMO

BACKGROUND: Despite having chronic gastritis, most people infected by Helicobacter pylori (H. pylori) are asymptomatic and have no specific clinical signs and symptoms. H. pylori infection can be diagnosed by several detection methods. Giemsa stain and rapid urease test (CLO test) are the most performed tests of H. pylori infection at first-line clinical examination because of their simplicity and reliability. However, the sensitivity of CLO test is significantly reduced in patients with atrophic gastritis and intestinal metaplasia, and the weaknesses of Giemsa stain are higher cost and time-consuming. METHODS: The Giemsa stain was modified in several staining solutions and procedures based on the simplified Giemsa technique described by Gray, Wyatt, & Rathbone (1986). The modified Giemsa stain is examined its efficacy and compared with the CLO test using 233 H. pylori-infected patients with gastric disease. RESULTS: The modified Giemsa stain is comparable to the traditional one. Statistical analysis indicated that the modified Giemsa stain obtains greater accuracy in H. pylori-infected patients with gastritis and ulcer than the CLO test (48.1% vs. 43.7%). Moreover, considering the prognosis of different symptoms of gastric diseases, the modified Giemsa stain has a more accurate prognosis than combination symptoms (P = 1.8E-05 vs. P = 5.49E-05). The modified Giemsa stain is confirmed to be better than CLO test using 233 H. pylori-infected patients with gastric disease. CONCLUSIONS: The modified Giemsa stain is more simplified and time-saving than traditional Giemsa stain, which is comparable to the traditional one and is confirmed to be better than CLO test using 233 H. pylori-infected patients with gastric disease. In clinical examination, this modified Giemsa stain can be applied to routine examination and provides quick and accurate diagnosis and prognosis to H. pylori-infected patients with gastric diseases.


Assuntos
Corantes Azur , Infecções por Helicobacter/diagnóstico , Infecções por Helicobacter/patologia , Urease , Biópsia , Gastrite/microbiologia , Humanos , Úlcera Gástrica/microbiologia , Urease/metabolismo
11.
J Vet Pharmacol Ther ; 43(6): 520-526, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32573800

RESUMO

Drug administration by immersion can be a preferable method in certain conditions especially for treating small-sized, anorexic, or valuable fish. Pharmacokinetic information regarding bath treatment is considerably lacking in comparison to other common administration routes. The current study aimed to investigate if immersion can be an effective route to administer florfenicol (FF) for treatment in Nile tilapia. Nile tilapia reared at 28°C were immersed with FF solution at concentrations of 50, 100, 200, 500, and 500/200 (3 hr/117 hr) ppm for 120 hr and moved to drug-free freshwater for another 24 hr. The serum FF concentration in 100, 200, and 500/200 ppm groups reached steady-state at 12 hr with concentrations of 2.44, 3.04, and 5.26 µg/ml, respectively, which were about 2% of the bathing concentrations. The target therapeutic levels of 1-4 µg/ml were attained and maintained within 1-12 hr, depending on the immersion concentration and the target MIC. Serum FF reached the target with shorter time at higher bathing concentration. Following the 120-hr bath, the serum FF declined with the first-order half-life of approximately 10 hr. A minimum of 100 ppm FF is required for treatment purpose, and an initial high loading concentration followed by maintenance concentration is a plausible way to reach in vivo therapeutic level in short time. Greater than 99% of the residual FF in the bathing water could be removed within 15 min by 0.05% NaOCl. Our results indicated that bath immersion is a promising potential route for FF administration in Nile tilapia.


Assuntos
Antibacterianos/farmacocinética , Ciclídeos/sangue , Tianfenicol/análogos & derivados , Animais , Antibacterianos/administração & dosagem , Antibacterianos/sangue , Área Sob a Curva , Relação Dose-Resposta a Droga , Vias de Administração de Medicamentos , Meia-Vida , Tianfenicol/administração & dosagem , Tianfenicol/sangue , Tianfenicol/farmacocinética
12.
J Fish Dis ; 42(8): 1181-1190, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31157416

RESUMO

Optimized dosing regimen is key to the effective use of antibacterials and to minimizing drug-related side effects. The current study established a pharmacokinetic-pharmacodynamic (PK-PD) model for the determination of optimal antibacterial dosing regimen in fish taken into consideration the temperature-dependent PK and the pathogen-dependent antimicrobial susceptibility, using florfenicol (FF) in Nile tilapia as an example. The calculated optimal dosages significantly varied by temperature and target MIC levels, ranging from 2.23 (MIC 1 µg/ml at 24°C) to 34.88 mg kg-1  day-1 (MIC 4 µg/ml at 32°C). The appropriateness of the calculated dosages was successfully verified by the in vivo studies. After 5 days of oral administration of the calculated optimal dosage at 24°C, the predicted plasma drug values were in line with the mean observed Cmin(ss) while at 28 and 32°C underestimation of the Cmin(ss) in a dose-dependent manner was observed and likely due to the occurrence of non-linear PK at high dosages. The averaged serum protein binding of FF was 19.1%. Our results demonstrated the appropriateness and clinical applicability of the developed PK-PD approach for the determination of optimal dosing regimens at given temperatures and MICs. Saturation metabolism and PK non-linearity of FF in tilapia warrant further study.


Assuntos
Antibacterianos/farmacologia , Ciclídeos/metabolismo , Tianfenicol/análogos & derivados , Administração Oral , Animais , Antibacterianos/administração & dosagem , Antibacterianos/farmacocinética , Relação Dose-Resposta a Droga , Testes de Sensibilidade Microbiana , Modelos Biológicos , Temperatura , Tianfenicol/administração & dosagem , Tianfenicol/farmacocinética , Tianfenicol/farmacologia , Água/química
13.
J Vet Pharmacol Ther ; 47(1): 62-63, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38047430
14.
Molecules ; 24(9)2019 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-31060204

RESUMO

Arterial pressure of each new breeding spontaneous Phase-1 hypertension (P1-HT) rat was recorded for 5 min by intravascular femoral artery catheter that served as a reference value prior to treatment. In the acute antihypertensive test, 0.36 g/kg Bwt of Plantago asiatica seed extract (PSE) was administered, via gavage feeding, to P1-HT rats, and the arterial pressures were continuously recorded for 1 h. The acute antihypertensive effects of PSE on P1-HT rats appeared within 15 min after PSE administration and lasted over 1 h with systolic pressure decreased 31.5 mmHg and diastolic pressure decreased 18.5 mmHg. The systolic pressure decreased 28 mmHg and diastolic pressure decreased 16 mmHg in P1-HT rats when simultaneously compared with verapamil hydrochloride (reference drug), whereas there were no significant differences in the pretreated reference values of acute PSE treatment and the untreated control. In the chronic test, P1-HT rats received 0.36 g/kg Bwt day of PSE or equal volume of water for 4 weeks via oral gavage, and the lower blood pressure tendencies of chronic PSE treatment were also found when compared with the controls. The antihypertensive values of PSE were also confirmed in spontaneously hypertensive rats (SHRs). Oral administration with PSE can effectively moderate blood pressure within an hour, while taking PSE daily can control the severity of hypertension, suggesting PSE is a potentially antihypertensive herb.


Assuntos
Hipertensão/tratamento farmacológico , Extratos Vegetais/administração & dosagem , Plantago/química , Verapamil/administração & dosagem , Administração Oral , Animais , Pressão Sanguínea/efeitos dos fármacos , Modelos Animais de Doenças , Esquema de Medicação , Humanos , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Ratos , Ratos Sprague-Dawley , Sementes/química , Verapamil/farmacologia
16.
Biochim Biophys Acta Proteins Proteom ; 1866(2): 214-223, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28988034

RESUMO

The TAR DNA-binding protein of 43kDa (TDP-43) has been identified as the main component of amyotrophic lateral sclerosis (ALS) cytoplasmic inclusions. The link between this proteinopathy and TDP-43's intrinsically disordered C-terminal domain is well known, but recently also, this domain has been shown to be involved in the formation of the membraneless organelles that mediate TDP-43's functions. The mechanisms that underpin the liquid-liquid phase separation (LLPS) of these membraneless organelles undergo remain elusive. Crucially though, these factors may be the key to understanding the delicate balance between TDP-43's physiological and pathological functions. In this study, we used nuclear magnetic resonance spectroscopy and optical methods to demonstrate that an α-helical component in the centre (residues 320-340) of the C-terminal domain is related to the protein's self-association and LLPS. Systematically analysing ALS-related TDP-43 mutants (G298S, M337V, and Q331K) in different buffer conditions at different temperatures, we prove that this phase separation is driven by hydrophobic interactions but is inhibited by electrostatic repulsion. Based on these findings, we rationally introduced a mutant, W334G, and demonstrate that this mutant disrupts LLPS without disturbing this α-helical propensity. This tryptophan may serve as a key residue in this protein's LLPS.


Assuntos
Proteínas de Ligação a DNA/química , Substituição de Aminoácidos , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Humanos , Mutação de Sentido Incorreto , Agregação Patológica de Proteínas/genética , Agregação Patológica de Proteínas/metabolismo , Domínios Proteicos
17.
Mol Cell Proteomics ; 15(1): 12-25, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26499836

RESUMO

Nosocomial infectious outbreaks caused by multidrug-resistant Acinetobacter baumannii have emerged as a serious threat to human health. Phosphoproteomics of pathogenic bacteria has been used to identify the mechanisms of bacterial virulence and antimicrobial resistance. In this study, we used a shotgun strategy combined with high-accuracy mass spectrometry to analyze the phosphoproteomics of the imipenem-susceptible strain SK17-S and -resistant strain SK17-R. We identified 410 phosphosites on 248 unique phosphoproteins in SK17-S and 285 phosphosites on 211 unique phosphoproteins in SK17-R. The distributions of the Ser/Thr/Tyr/Asp/His phosphosites in SK17-S and SK17-R were 47.0%/27.6%/12.4%/8.0%/4.9% versus 41.4%/29.5%/17.5%/6.7%/4.9%, respectively. The Ser-90 phosphosite, located on the catalytic motif S(88)VS(90)K of the AmpC ß-lactamase, was first identified in SK17-S. Based on site-directed mutagenesis, the nonphosphorylatable mutant S90A was found to be more resistant to imipenem, whereas the phosphorylation-simulated mutant S90D was sensitive to imipenem. Additionally, the S90A mutant protein exhibited higher ß-lactamase activity and conferred greater bacterial protection against imipenem in SK17-S compared with the wild-type. In sum, our results revealed that in A. baumannii, Ser-90 phosphorylation of AmpC negatively regulates both ß-lactamase activity and the ability to counteract the antibiotic effects of imipenem. These findings highlight the impact of phosphorylation-mediated regulation in antibiotic-resistant bacteria on future drug design and new therapies.


Assuntos
Acinetobacter baumannii/efeitos dos fármacos , Proteínas de Bactérias/metabolismo , Imipenem/farmacologia , Proteoma/metabolismo , Proteômica/métodos , beta-Lactamases/metabolismo , Acinetobacter baumannii/genética , Acinetobacter baumannii/metabolismo , Antibacterianos/farmacologia , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Sítios de Ligação/genética , Infecção Hospitalar/microbiologia , Humanos , Modelos Moleculares , Mutação , Fosfoproteínas/metabolismo , Fosforilação , Estrutura Terciária de Proteína , Espectrometria de Massas em Tandem , Resistência beta-Lactâmica/efeitos dos fármacos , beta-Lactamases/química , beta-Lactamases/genética
18.
J Sci Food Agric ; 98(2): 751-757, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28675436

RESUMO

BACKGROUND: The flavor and quality of tea are widely believed to be associated with the pot in which the tea is made. However, this claim is mostly by experiences and lacks solid support from scientific evidence. The current study investigated and compared the chemical compositions of oolong tea made with six different teapot materials, namely Zisha, Zhuni, stainless steel, ceramic, glass and plastic. RESULTS: For each tea sample, polyphenols and caffeine were examined by HPLC-UV, volatile compounds by GC/MS, amino acids by LC/MS and minerals by ICP-MS. The results suggested that tea infusions from Zisha and Zhuni pots contain higher levels of EGC, EGCG and total catechins and less caffeine than those from ceramic, glass and plastic pots and tend to have the lowest total mineral contents, potassium and volatile compounds in tea soup. The statistical differences were not all significant among Zisha, Zhuni and stainless steel pots. CONCLUSION: Based on the overall chemical composition of the tea infusion, Yixing clay pots (Zisha and Zhuni) produce tea infusions that are presumably less bitter and more fragrant and tend to contain more healthful compounds than tea infusions from other pots. The results could partially explain why Yixing clay pots are among the most popular teapots. The beneficial effects of long-term repeated use of these teapots warrants further study. © 2017 Society of Chemical Industry.


Assuntos
Silicatos de Alumínio/química , Cerâmica/química , Vidro/química , Plásticos/química , Aço Inoxidável/química , Chá/química , Argila , Folhas de Planta/química
19.
Biochim Biophys Acta ; 1853(1): 222-32, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25447673

RESUMO

Valosin-containing protein (VCP or p97), a member of the AAA family (ATPases associated with diverse cellular activities), plays a key role in many important cellular activities. A genetic deficiency of VCP can cause inclusion body myopathy associated with Paget's disease of bone and frontotemporal dementia (IBMPFD). Previous studies showed that the VCP N domain is essential for the regulation of nuclear entry of VCP. Here we report that IBMPFD mutations, which are mainly located in the N domain, suppress the nuclear entry of VCP. Moreover, the peptide sequence G780AGPSQ in the C-terminal region regulates the retention of VCP in the nucleus. A mutant lacking this sequence can increase the nuclear distribution of IBMPFD VCP, suggesting that this sequence is a potential molecular target for correcting the deficient nucleocytoplasmic shuttling of IBMPFD VCP proteins.


Assuntos
Adenosina Trifosfatases/metabolismo , Proteínas de Ciclo Celular/metabolismo , Núcleo Celular/metabolismo , Transporte Ativo do Núcleo Celular , Adenosina Trifosfatases/química , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/fisiologia , Proteínas de Ciclo Celular/química , Proteínas de Ciclo Celular/genética , Demência Frontotemporal/genética , Células HEK293 , Humanos , Distrofia Muscular do Cíngulo dos Membros/genética , Miosite de Corpos de Inclusão/genética , Osteíte Deformante/genética , Estrutura Terciária de Proteína , Proteína com Valosina
20.
Int J Med Sci ; 13(2): 117-23, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26941570

RESUMO

The aldosterone synthase gene, cytochrome P450 11B2 (CYP11B2), and mineralocorticoid receptor (MR) genes have been reported to be associated with coronary artery disease (CAD). In this study, we investigated the association of single nucleotide polymorphisms (SNPs) of CYP11B2 (CYP11B2 T-344C) and MR (MR C3514G and MR C4582A) with CAD in Taiwanese. Six hundred and nine unrelated male and female subjects who received elective coronary angiography were recruited from Chung Shan Medical University Hospital. The enrolled subjects were those who had a positive noninvasive test. CYP11B2 T-344C, MR C3514G and MR C4582A were determined by polymerase chain reaction-restriction fragment length polymorphism. We found that women with CYP11B2 C/C had a higher risk of developing CAD. However, there were no significant differences in the genotype distributions of MR C3514G and MR C4582A between the women with and without CAD. In multivariate analysis, CYP11B2 T-344C was most significantly associated with CAD in Taiwanese women. In conclusions, CYP11B2 C/C was more significantly associated with the development of CAD than diabetes mellitus or hypertension. This implies that CYP11B2 C/C plays a more important role than some conventional risk factors in the development of CAD in Taiwanese women.


Assuntos
Doença da Artéria Coronariana/genética , Citocromo P-450 CYP11B2/genética , Polimorfismo de Nucleotídeo Único , Receptores de Mineralocorticoides/genética , Idoso , Feminino , Frequência do Gene , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Taiwan
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