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1.
Zhongguo Yi Liao Qi Xie Za Zhi ; 45(3): 349-354, 2021 Jun 08.
Artigo em Chinês | MEDLINE | ID: mdl-34096251

RESUMO

OBJECTIVE: Whether the developed new type of radiotherapy auxiliary fixation device compatible with the head and neck joint coil can improve the quality of magnetic resonance images in radiotherapy and verify whether it can be applied to clinical treatment. METHODS: The clinical trial selected patients with brain metastases and nasopharyngeal cancer patients, using thermoplastic film and head and shoulder molds for posture fixation, and treatment on the ELekta Versa accelerator. SPSS 20.0 statistical software was used to analyze the data. The measurement data were expressed by X±S, and the t test was used. P<0.05 was considered as statistically significant. RESULTS: Considering the influence of the outer contour of the device, the target dose meets the clinical requirements. The setting error is less than 2 mm in the three translation directions, and the rotation error is less than 2o in the three rotation directions. CONCLUSIONS: There is no statistical difference between the treatment results of patients using the new type of fixation device and the conventional method. The target area threatens the organ dose, and the positioning error meets the treatment requirements.


Assuntos
Neoplasias Nasofaríngeas , Humanos , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Pescoço , Postura
2.
Nan Fang Yi Ke Da Xue Xue Bao ; 41(5): 783-788, 2021 May 20.
Artigo em Chinês | MEDLINE | ID: mdl-34134968

RESUMO

OBJECTIVE: To evaluate the performance of 1H-magnetic resonance spectroscopy (1H-MRS), Dixon fat-water separation and Z-spectral magnetic resonance imaging (ZS-MRI) for quantification of fat content in phantoms and brown adipose tissues in rats. OBJECTIVE: First, six water-oil mixture phantoms with different fat fractions (0, 20%, 40%, 60%, 80% and 100%) were prepared and placed in a 50-mL centrifuge tube. ZS-MRI, 1H-MRS and Dixon's method were used to quantitatively evaluate the fat content of the phantom, and the results were compared against the actual fat fractions. Then, ZS-MRI and Dixon's method were used to collect the data in the interscapular region of 6 rats, the fat-water distribution map was calculated, and the results were compared with 1H-MRS. OBJECTIVE: ZS-MRI accurately quantified fat contents in the phantoms (Y=0.95*X+1.48). ZS-MRI was capable of distinguishing brown adipose tissue from white adipose tissue and defining the spatial distribution of the adipose tissue, and the results were highly consistent with those obtained by Dixon's method. No significant differences were found in the results derived by ZS-MRI and 1H-MRS for quantification of brown adipose tissue (P=0.35). OBJECTIVE: ZS-MRI can generate an artifact-free fat distribution map for quantitative measurement of the content and distribution of brown adipose tissues in rats.


Assuntos
Tecido Adiposo Marrom , Água , Tecido Adiposo/diagnóstico por imagem , Tecido Adiposo Marrom/diagnóstico por imagem , Animais , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Espectroscopia de Prótons por Ressonância Magnética , Ratos
3.
Intern Med ; 60(12): 1813-1818, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34135267

RESUMO

Objective Following the introduction of magnetic resonance (MR)-conditional cardiac implantable electrical devices (CIEDs), patients with CIEDs have undergone MRI scanning more frequently. As the required settings of MRI equipment for scanning patients with a CIED vary by device, a number of precautions should be taken to allow safe examinations, including the confirmation of conditions and selection of MRI modes appropriate for pacing status in individual patients. In this study, we examined the current status and issues concerning the performance of MRI examinations in patients with an MRI-conditional CIED. Method and Results We reviewed a total of 262 MRI scans. The most common site of MRI scanning was the head, followed by the spine, abdomen, and heart in order. Regarding the MRI mode, DOO was most often used, followed by OFF, AOO, and finally VOO mode, to maintain atrioventricular synchrony. Although no obvious adverse events were observed related to MRI scanning, there were several cases encountered that might have been predisposed to a significant incident or in which the patient's intrinsic pulse rates or subjective symptoms changed before and during scanning. Conclusion As MRI is a very useful diagnostic tool for cerebrovascular diseases and orthopedic disorders, the demand for MRI scanning is high when treating these areas. Although MRI scanning in patients with MR-conditional devices was performed without any adverse events, there were incidents that could have potentially led to major harm. This highlights the importance of confirming the appropriate MRI mode is being used before scanning and monitoring patients during scanning.


Assuntos
Desfibriladores Implantáveis , Marca-Passo Artificial , Desfibriladores Implantáveis/efeitos adversos , Coração , Humanos , Imageamento por Ressonância Magnética/efeitos adversos , Espectroscopia de Ressonância Magnética
4.
Zhonghua Xin Xue Guan Bing Za Zhi ; 49(6): 601-609, 2021 Jun 24.
Artigo em Chinês | MEDLINE | ID: mdl-34126728

RESUMO

Objective: To explore the clinical value of quantitatively assessment of left ventricular strain in patients with coronary chronic total occlusion (CTO) by cardiac magnetic resonance imaging (CMR)-feature tracking (CMR-FT) technique. Methods: In this retrospective and observation study, patients with single CTO, who underwent CMR examination in Beijing Anzhen Hospital from November 2014 to January 2019, were selected as case group (CTO group), and those without cardiovascular diseases defined by echocardiography, electrocardiogram (ECG) and clinical history and with normal CMR results were selected as healthy control group (control group). General clinical data including age, gender, discharge diagnosis, and the examination results of echocardiography and ECG were obtained from the electronic medical record system. Two-dimensional CMR-FT was applied to measure left ventricle (LV) global peak radial, circumferential, and longitudinal strains (GPRS, GPCS and GPLS, respectively), and the regional myocardial strain in the target vessel area of CTO was analyzed. Grayscale thresholds of 5 standard deviations (SDs) were used to quantify late gadolinium enhancement (LGE). Patients with CTOs were divided into infract size>10% group and infarct size≤10% group, and left ventricular ejection fraction (LVEF)≥50% group and LVEF<50% group, respectively. The differences between various groups were compared. Results: There were 52 patients in CTO group (34 males, age (54.1±11.7) years, body mass index (BMI) (26.2±2.5)kg/m2) and 30 patients in control group (14 males, age(51.6±12.3)years, BMI (25.6±3.3)kg/m2). There was no significant difference in age, gender, and BMI between the two groups (all P>0.05). LVEF, GPRS, GPCS and GPLS were significantly lower in CTO group than in control group (all P<0.05), left ventricular volume (LVEDV) was similar between the two groups (P>0.05). Among the patients with CTO, there were 26 patients with infarct size>10% and 26 patients with infarct size≤10%. GPRS, GPCS and GPLS were significantly lower (all P<0.05), while LVEF and LVEDV were similar in CTO patients with infarct size≤10% as compared to control group (both P>0.05). LVEF, GPRS, GPCS and GPLS were significantly lower (all P<0.05), while LVEDV was similar in CTO patients with infarct size>10% (P>0.05) as compared to control group. GPRS and GPCS were significantly lower (both P<0.05), while LVEF, LVEDV and GPLS were similar in CTO patients with infarct size>10% as compared to infarct size≤10% group. There were 40 subjects in LVEF≥50% group and 12 subjects in LVEF<50% group. Compared with the control group, GPCS and GPLS of CTO patients were significantly lower in LVEF≥50% group and LVEF<50% group (all P<0.01), LVEF and LVEDV was similar in CTO patients with LVEF≥50% (both P>0.05), but LVEF was lower and LVEDV was larger in LVEF<50% group (both P<0.05). The GPRS, GPCS, GPLS and LVEF of CTO patients in LVEF ≥ 50% group were higher than those in LVEF<50% group (all P<0.0l), and the myocardial infarction size was smaller than that in LVEF reduced group (P<0.0l), but there was no significant difference in LVEDV between the two groups (P=0.07). In the CTO group, there were 21 patients with left anterior descending artery (LAD) occlusion and 126 segments supplied by the target vessels. The peak radial strain (PRS), circumferential strain (PCS) and longitudinal strain (PLS) in the blood supply area were lower than those in the control group (all P<0 01). In 7 patients with left circumflex artery (LCX) occlusion, the number of myocardial segments supplied by the target vessels was 35, and the PRS, PCS and PLS in the target vessel supply area were lower than those in the control group (all P<0 05). In 24 patients with right coronary artery (RCA) occlusion, the number of myocardial segments supplied by the target vessels was 120, and the PRS, PCS and PLS in the target vessel supply area were lower than those in the control group (all P<0.01). Among the 126 segments in 21 patients with LAD CTO, 91 (72.2%) segments had infarct size≤25%, 17 (13.5%) segments had infarct size between 26%-50%, 11 segments (8.7%) had infarct size between 51%-75%, and 7 (5.6%) segments had infarct size between 76%-100%. Among the 35 segments in 7 patients with LCX CTO, 31 (88.6%) segments had infarct size≤25%, and 4 (11.4%) segments had infarct size between 26%-75%. Among the 120 segments in 24 patients with RCA CTO, 96 (80.0%) segments had infarct size≤25%, 11 (9.2%) segments had infarct size between 26%-50%, 8 (6.7%) segments had infarct size between 51%-75%, and 5 segments (4.2%) had infarct size between 76%-100%. Conclusions: In this study with single CTO, although the LVEF is preserved in the majority of the patients, the left ventricular global and regional strain values are significantly decreased. The larger the infarct size, the greater the impact on radial and circumferential motion, reflecting the early impairment of left ventricular function in these patients.


Assuntos
Oclusão Coronária , Intervenção Coronária Percutânea , Adulto , Idoso , Meios de Contraste , Oclusão Coronária/diagnóstico por imagem , Gadolínio , Ventrículos do Coração/diagnóstico por imagem , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Volume Sistólico , Função Ventricular Esquerda
5.
Int J Mol Sci ; 22(11)2021 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-34072418

RESUMO

Staphylococcus aureus is one of the most prevalent pathogens associated with several types of biofilm-based infections, including infections of chronic wounds. Mature staphylococcal biofilm is extremely hard to eradicate from a wound and displays a high tendency to induce recurring infections. Therefore, in the present study, we aimed to investigate in vitro the interaction between S. aureus biofilm and fibroblast cells searching for metabolites that could be considered as potential biomarkers of critical colonization and infection. Utilizing advanced microscopy and microbiological methods to examine biofilm formation and the staphylococcal infection process, we were able to distinguish 4 phases of biofilm development. The analysis of staphylococcal biofilm influence on the viability of fibroblasts allowed us to pinpoint the moment of critical colonization-12 h post contamination. Based on the obtained model we performed a metabolomics analysis by 1H NMR spectroscopy to provide new insights into the pathophysiology of infection. We identified a set of metabolites related to the switch to anaerobic metabolism that was characteristic for staphylococcal biofilm co-cultured with fibroblast cells. The data presented in this study may be thus considered a noteworthy but preliminary step in the direction of developing a new, NMR-based tool for rapid diagnosing of infection in a chronic wound.


Assuntos
Biofilmes/crescimento & desenvolvimento , Técnicas de Cocultura , Fibroblastos/metabolismo , Fibroblastos/microbiologia , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus aureus/metabolismo , Sobrevivência Celular , Fibroblastos/ultraestrutura , Imunofluorescência , Interações Hospedeiro-Patógeno , Cinética , Espectroscopia de Ressonância Magnética , Metaboloma , Metabolômica/métodos , Staphylococcus aureus/ultraestrutura
6.
Int J Mol Sci ; 22(11)2021 May 29.
Artigo em Inglês | MEDLINE | ID: mdl-34072560

RESUMO

The synthesis of new phenothiazine derivatives, analogs of Methylene Blue, is of particular interest in the design of new drugs, as well as in the development of a new generation of agents for photodynamic therapy. In this study, two new derivatives of phenothiazine, i.e., 3,7-bis(4-aminophenylamino)phenothiazin-5-ium chloride dihydrochloride (PTZ1) and 3,7-bis(4-sulfophenylamino)phenothiazin-5-ium chloride (PTZ2), are synthesized for the first time and characterized by NMR, IR spectroscopy, HRMS and elemental analysis. The interaction of the obtained compounds PTZ1 and PTZ2 with salmon sperm DNA is investigated. It is shown by UV-Vis spectroscopy and DFT calculations that substituents in arylamine fragments play a crucial role in dimer formation and interaction with DNA. In the case of PTZ1, two amine groups promote H-aggregate formation and DNA interactions through groove binding and intercalation. In the case of PTZ2, sulfanilic acid fragments prevent any dimer formation and DNA binding due to electrostatic repulsion. DNA interaction mechanisms are studied and confirmed by UV-vis and fluorescence spectroscopy in comparison with Methylene Blue. The obtained results open significant opportunities for the development of new drugs and photodynamic agents.


Assuntos
Aminas/química , Aminas/farmacologia , Azul de Metileno/química , Azul de Metileno/farmacologia , Aminas/síntese química , DNA/química , Dimerização , Substâncias Intercalantes/química , Substâncias Intercalantes/farmacologia , Espectroscopia de Ressonância Magnética , Azul de Metileno/síntese química , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Espectrometria de Fluorescência , Relação Estrutura-Atividade
7.
Medicina (Kaunas) ; 57(6)2021 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-34072775

RESUMO

Background and Objectives: Obstructive sleep apnea (OSA) is a common disorder with an increased risk for left ventricular and right ventricular dysfunction. Most studies to date have examined populations with manifest cardiovascular disease using echocardiography to analyze ventricular dysfunction with little or no reference to ventricular volumes or myocardial mass. Our aim was to explore these parameters with cardiac MRI. We hypothesized that there would be stepwise increase in left ventricular mass and right ventricular volumes from the unaffected, to the snoring and the OSA group. Materials and Methods: We analyzed cardiac MRI data from 4978 UK Biobank participants free from cardiovascular disease. Participants were allocated into three cohorts: with OSA, with self-reported snoring and without OSA or snoring (n = 118, 1886 and 2477). We analyzed cardiac parameters from balanced cine-SSFP sequences and indexed them to body surface area. Results: Patients with OSA were mostly males (47.3% vs. 79.7%; p < 0.001) with higher body mass index (25.7 ± 4.0 vs. 31.3 ± 5.3 kg/m²; p < 0.001) and higher blood pressure (135 ± 18 vs. 140 ± 17 mmHg; p = 0.012) compared to individuals without OSA or snoring. Regression analysis showed a significant effect for OSA in left ventricular end-diastolic index (LVEDVI) (ß = -4.9 ± 2.4 mL/m²; p = 0.040) and right ventricular end-diastolic index (RVEDVI) (ß = -6.2 ± 2.6 mL/m²; p = 0.016) in females and for right ventricular ejection fraction (RVEF) (ß = 1.7 ± 0.8%; p = 0.031) in males. A significant effect was discovered in snoring females for left ventricular mass index (LVMI) (ß = 3.5 ± 0.9 g/m²; p < 0.001) and in males for left ventricular ejection fraction (LVEF) (ß = 1.0 ± 0.3%; p = 0.001) and RVEF (ß = 1.2 ± 0.3%; p < 0.001). Conclusion: Our study suggests that OSA is highly underdiagnosed and that it is an evolving process with gender specific progression. Females with OSA show significantly lower ventricular volumes while males with snoring show increased ejection fractions which may be an early sign of hypertrophy. Separate prospective studies are needed to further explore the direction of causality.


Assuntos
Bancos de Espécimes Biológicos , Ronco , Feminino , Humanos , Imageamento por Ressonância Magnética , Espectroscopia de Ressonância Magnética , Masculino , Estudos Prospectivos , Ronco/diagnóstico por imagem , Volume Sistólico , Reino Unido , Função Ventricular Esquerda , Função Ventricular Direita
8.
Int J Mol Sci ; 22(9)2021 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-34066973

RESUMO

L-methionine, an essential amino acid, plays a critical role in cell physiology. High intake and/or dysregulation in methionine (Met) metabolism results in accumulation of its intermediate(s) or breakdown products in plasma, including homocysteine (Hcy). High level of Hcy in plasma, hyperhomocysteinemia (hHcy), is considered to be an independent risk factor for cerebrovascular diseases, stroke and dementias. To evoke a mild hHcy in adult male Wistar rats we used an enriched Met diet at a dose of 2 g/kg of animal weight/day in duration of 4 weeks. The study contributes to the exploration of the impact of Met enriched diet inducing mild hHcy on nervous tissue by detecting the histo-morphological, metabolomic and behavioural alterations. We found an altered plasma metabolomic profile, modified spatial and learning memory acquisition as well as remarkable histo-morphological changes such as a decrease in neurons' vitality, alterations in the morphology of neurons in the selective vulnerable hippocampal CA 1 area of animals treated with Met enriched diet. Results of these approaches suggest that the mild hHcy alters plasma metabolome and behavioural and histo-morphological patterns in rats, likely due to the potential Met induced changes in "methylation index" of hippocampal brain area, which eventually aggravates the noxious effect of high methionine intake.


Assuntos
Comportamento Animal , Hipocampo/patologia , Hiper-Homocisteinemia/sangue , Hiper-Homocisteinemia/metabolismo , Metabolômica , Animais , Homocisteína/sangue , Hiper-Homocisteinemia/patologia , Marcação In Situ das Extremidades Cortadas , Espectroscopia de Ressonância Magnética , Masculino , Metionina , Ratos Wistar , Coloração e Rotulagem
9.
Rev. venez. cir. ortop. traumatol ; 53(1): 20-26, jun. 2021. ilus
Artigo em Espanhol | LILACS, LIVECS | ID: biblio-1252895

RESUMO

Cuando fracasa el tratamiento conservador en el Estadio I de Disfunción del Tendón Tibial posterior (DTTP), se debe indicar sinovectomía y debridamiento del tendón. En este estudio evaluamos la evolución con 8 años mínimo de seguimiento, de los pacientes con esta patología tratados vía tenoscópica. Este es un estudio retrospectivo de pacientes operados entre el año 2008 y el año 2011. En ese período de tiempo se intervinieron 11 pacientes con esta patología. Sólo 9 de los 11 pacientes operados pudieron ser evaluados. 7 pacientes mejoraron su sintomatología según el VAS y no progresaron a estadio II. En 3 pacientes se evidenció lesión tendinosa durante la tendoscopía y ameritaron reparación a cielo abierto. La sinovectomía tendoscópica del TTP es un procedimiento quirúrgico efectivo para tratar a los pacientes con DTTP Estadio I, rebeldes a tratamiento conservador(AU)


When conservative treatment fails for Stage I Posterior Tibial tendon dysfunction (PTTD), synovectomy and tendon debridement is indicated. In this study we evaluate tendoscopic treatment results for this pathology with a minimum of 8 years follow up. This is a retrospective study of patients after tendoscopic surgery performed between 2008 and 2011. 9 of the 11 patients were available for evaluation. 7 improved their symptoms according to VAS scale, and did not progress to stage II. In 3 patients tendon tear was visualized during tendoscopy and needed open repair. PTT tendoscopy is an effective surgical treatment to treat Stage I PTTD, failing to conservative treatment(AU)


Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Pé Chato , Espectroscopia de Ressonância Magnética , Anti-Inflamatórios não Esteroides/uso terapêutico , Disfunção do Tendão Tibial Posterior/patologia , Tendinopatia , Sinovectomia , Ultrassom , Crioterapia , Técnicas e Procedimentos Diagnósticos , Desbridamento
10.
Elife ; 102021 05 04.
Artigo em Inglês | MEDLINE | ID: mdl-33942721

RESUMO

Biomarkers of low-grade inflammation have been associated with susceptibility to a severe infectious disease course, even when measured prior to disease onset. We investigated whether metabolic biomarkers measured by nuclear magnetic resonance (NMR) spectroscopy could be associated with susceptibility to severe pneumonia (2507 hospitalised or fatal cases) and severe COVID-19 (652 hospitalised cases) in 105,146 generally healthy individuals from UK Biobank, with blood samples collected 2007-2010. The overall signature of metabolic biomarker associations was similar for the risk of severe pneumonia and severe COVID-19. A multi-biomarker score, comprised of 25 proteins, fatty acids, amino acids, and lipids, was associated equally strongly with enhanced susceptibility to severe COVID-19 (odds ratio 2.9 [95%CI 2.1-3.8] for highest vs lowest quintile) and severe pneumonia events occurring 7-11 years after blood sampling (2.6 [1.7-3.9]). However, the risk for severe pneumonia occurring during the first 2 years after blood sampling for people with elevated levels of the multi-biomarker score was over four times higher than for long-term risk (8.0 [4.1-15.6]). If these hypothesis generating findings on increased susceptibility to severe pneumonia during the first few years after blood sampling extend to severe COVID-19, metabolic biomarker profiling could potentially complement existing tools for identifying individuals at high risk. These results provide novel molecular understanding on how metabolic biomarkers reflect the susceptibility to severe COVID-19 and other infections in the general population.


Assuntos
COVID-19/sangue , Metaboloma , Aminoácidos/sangue , Biomarcadores/sangue , COVID-19/epidemiologia , Ácidos Graxos/sangue , Humanos , Lipídeos/sangue , Espectroscopia de Ressonância Magnética , Programas de Rastreamento/estatística & dados numéricos
11.
J Phys Chem B ; 125(20): 5171-5190, 2021 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-33960784

RESUMO

Nuclear magnetic resonance (NMR) spectroscopy is a powerful method to study the molecular structure and dynamics of materials. The inherently low sensitivity of NMR spectroscopy is a consequence of low spin polarization. Hyperpolarization of a spin ensemble is defined as a population difference between spin states that far exceeds what is expected from the Boltzmann distribution for a given temperature. Dynamic nuclear polarization (DNP) can overcome the relatively low sensitivity of NMR spectroscopy by using a paramagnetic matrix to hyperpolarize a nuclear spin ensemble. Application of DNP to NMR can result in sensitivity gains of up to four orders of magnitude compared to NMR without DNP. Although DNP NMR is now more routinely utilized for solid-state (ss) NMR spectroscopy, it has not been exploited to the same degree for liquid-state samples. This Review will consider challenges and advances in the application of DNP NMR to liquid-state samples. The Review is organized into four sections: (i) mechanisms of DNP NMR relevant to hyperpolarization of liquid samples; (ii) applications of liquid-state DNP NMR; (iii) available detection schemes for liquid-state samples; and (iv) instrumental challenges and outlook for liquid-state DNP NMR.


Assuntos
Espectroscopia de Ressonância Magnética , Estrutura Molecular , Temperatura
12.
Arch Esp Urol ; 74(4): 411-418, 2021 May.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-33942734

RESUMO

OBJECTIVE: To evaluate the quality of the contrast images obtained with a Primovist® (gadoxetate disodium) Magnetic Resonance Image in order to diagnose benign, malignant and malformations in the urinary tract. MATERIAL AND METHODS: A retrospective image and diagnosis review of Primovist® MRI studies performed in liver insufficient patients without apparent renal abnormalities was done, in order to evaluate the urinary tract for irregularities. RESULTS: A total of 117 Primovist® MRI studies performed between july 2014 and November 2018 were reviewed, 5 were excluded because they were incomplete. The average age was 59.6 ± 16.6 years old. The following diagnosis were encountered: 36 simple cysts, 6 perirenal fibrosis after pyelonephritis, 1 renal cancer, 1 renal atrophy, 1 proximal uretheric flexure, 1 bilateral hydronephrosis due to lower urinary obstruction because of benign prostatic hyperplasia and 1 complex cyst. No MRI study was indicated with suspicions of renal abnormalities. Relevant images are included that demonstrate the capability of Primovist® MRI to diagnose renal abnormalities. CONCLUSION: Even though none of the Primovist® MRI studies was done with suspicious of renal abnormalities it was possible to diagnose incidental benign, malignant and malformations of the urinary tract. This study shows how Primovist® MRI can be useful contrast study for urinary tract irregularities.


Assuntos
Meios de Contraste , Rim , Adulto , Idoso , Gadolínio DTPA , Humanos , Rim/diagnóstico por imagem , Espectroscopia de Ressonância Magnética , Pessoa de Meia-Idade , Estudos Retrospectivos
13.
J Vis Exp ; (170)2021 04 19.
Artigo em Inglês | MEDLINE | ID: mdl-33938889

RESUMO

Protein conformational dynamics play fundamental roles in regulation of enzymatic catalysis, ligand binding, allostery, and signaling, which are important biological processes. Understanding how the balance between structure and dynamics governs biological function is a new frontier in modern structural biology and has ignited several technical and methodological developments. Among these, CPMG relaxation dispersion solution NMR methods provide unique, atomic-resolution information on the structure, kinetics, and thermodynamics of protein conformational equilibria occurring on the µs-ms timescale. Here, the study presents detailed protocols for acquisition and analysis of a 15N relaxation dispersion experiment. As an example, the pipeline for the analysis of the µs-ms dynamics in the C-terminal domain of bacteria Enzyme I is shown.


Assuntos
Espectroscopia de Ressonância Magnética/métodos , Conformação Proteica , Cinética , Isótopos de Nitrogênio , Termodinâmica
14.
Food Chem ; 359: 129804, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34015560

RESUMO

Mutual adulterations of lemon and lime juices may be detected using coumarins and psoralens as markers. Poor manufacturing practices or legal but mechanically intense processing of lemons were recently suspected to lead to false accusations of deliberate adulterations with lime juices due to potentially unspecific markers. Therefore, we studied coumarin and psoralen profiles in carefully dissected flavedo, albedo, and endocarp of lime and lemon as well as in juices produced under variable mechanical stresses at laboratory and pilot plant scale. Although the marker herniarin was detectable in juices from lime and harshly extracted lemons at low levels, isopimpinellin, bergapten and the herein proposed, tentatively assigned 5-geranyloxy-8-methoxypsoralen represented unambiguously lime-specific markers. Coumarin and psoralen data also allowed differentiating juices produced at differing degrees of mechanical stress. The latter was also possible using quantitative 1H-NMR spectroscopy, which yielded best results when combined with HPLC data on coumarins and psoralens. In the future, the reported approach may be used for establishing a robust database prior to being used in industrial practice.


Assuntos
Citrus/química , Cumarínicos/análise , Análise de Alimentos/métodos , Sucos de Frutas e Vegetais/análise , Furocumarinas/análise , Espectroscopia de Ressonância Magnética
15.
Molecules ; 26(9)2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33946338

RESUMO

The genus Datura (Solanaceae) contains nine species of medicinal plants that have held both curative utility and cultural significance throughout history. This genus' particular bioactivity results from the enormous diversity of alkaloids it contains, making it a valuable study organism for many disciplines. Although Datura contains mostly tropane alkaloids (such as hyoscyamine and scopolamine), indole, beta-carboline, and pyrrolidine alkaloids have also been identified. The tools available to explore specialized metabolism in plants have undergone remarkable advances over the past couple of decades and provide renewed opportunities for discoveries of new compounds and the genetic basis for their biosynthesis. This review provides a comprehensive overview of studies on the alkaloids of Datura that focuses on three questions: How do we find and identify alkaloids? Where do alkaloids come from? What factors affect their presence and abundance? We also address pitfalls and relevant questions applicable to natural products and metabolomics researchers. With both careful perspectives and new advances in instrumentation, the pace of alkaloid discovery-from not just Datura-has the potential to accelerate dramatically in the near future.


Assuntos
Alcaloides/química , Produtos Biológicos/química , Datura/química , Compostos Fitoquímicos/química , Alcaloides/análise , Alcaloides/isolamento & purificação , Alcaloides/metabolismo , Produtos Biológicos/análise , Produtos Biológicos/isolamento & purificação , Produtos Biológicos/metabolismo , Fracionamento Químico , Fenômenos Químicos , Cromatografia Líquida , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Estrutura Molecular , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/isolamento & purificação , Compostos Fitoquímicos/metabolismo , Relação Estrutura-Atividade
16.
Molecules ; 26(9)2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33946512

RESUMO

For decades, high-resolution 1H NMR spectroscopy has been routinely utilized to analyze both naturally occurring steroid hormones and synthetic steroids, which play important roles in regulating physiological functions in humans. Because the 1H signals are inevitably superimposed and entangled with various JH-H splitting patterns, such that the individual 1H chemical shift and associated JH-H coupling identities are hardly resolved. Given this, applications of thess information for elucidating steroidal molecular structures and steroid/ligand interactions at the atomic level were largely restricted. To overcome, we devoted to unraveling the entangled JH-H splitting patterns of two similar steroidal compounds having fully unsaturated protons, i.e., androstanolone and epiandrosterone (denoted as 1 and 2, respectively), in which only hydroxyl and ketone substituents attached to C3 and C17 were interchanged. Here we demonstrated that the JH-H values deduced from 1 and 2 are universal and applicable to other steroids, such as testosterone, 3ß, 21-dihydroxygregna-5-en-20-one, prednisolone, and estradiol. On the other hand, the 1H chemical shifts may deviate substantially from sample to sample. In this communication, we propose a simple but novel scheme for resolving the complicate JH-H splitting patterns and 1H chemical shifts, aiming for steroidal structure determinations.


Assuntos
Espectroscopia de Ressonância Magnética , Acoplamento Oxidativo , Esteroides/química , Modelos Biológicos , Conformação Molecular , Estrutura Molecular
17.
Mar Drugs ; 19(5)2021 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-33947080

RESUMO

Marine polycyclic ether natural products have gained significant interest from the chemical community due to their impressively huge molecular architecture and diverse biological functions. The structure assignment of this class of extraordinarily complex natural products has mainly relied on NMR spectroscopic analysis. However, NMR spectroscopic analysis has its own limitations, including configurational assignment of stereogenic centers within conformationally flexible systems. Chemical shift deviation analysis of synthetic model compounds is a reliable means to assign the relative configuration of "difficult" stereogenic centers. The complete configurational assignment must be ultimately established through total synthesis. The aim of this review is to summarize the indispensable role of organic synthesis in stereochemical assignment of marine polycyclic ethers.


Assuntos
Organismos Aquáticos/metabolismo , Éteres Cíclicos/síntese química , Técnicas de Química Sintética , Ciguatoxinas/síntese química , Ciguatoxinas/isolamento & purificação , Éteres/síntese química , Éteres/isolamento & purificação , Éteres Cíclicos/isolamento & purificação , Humanos , Espectroscopia de Ressonância Magnética , Toxinas Marinhas/síntese química , Toxinas Marinhas/isolamento & purificação , Estrutura Molecular , Oxocinas/síntese química , Oxocinas/isolamento & purificação , Polímeros/síntese química , Polímeros/isolamento & purificação , Metabolismo Secundário , Estereoisomerismo , Relação Estrutura-Atividade
18.
Am J Case Rep ; 22: e930103, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33990535

RESUMO

BACKGROUND Clozapine, a second-generation antipsychotic, is often prescribed for refractory schizophrenia; however, it can cause life-threatening adverse events including agranulocytosis and myocarditis. Making the diagnosis of clozapine-induced myocarditis can be challenging given the non-specific presentation as well as risk involved in obtaining an endomyocardial biopsy. As clozapine-induced myocarditis carries a mortality risk of up to 30%, timely recognition, diagnosis, and management are vital. This report presents a case of clozapine-induced myocarditis in a 25-year-old man with refractory schizophrenia who was diagnosed using non-invasive imaging with cardiovascular magnetic resonance (CMR). CASE REPORT A 25-year-old man with refractory schizophrenia was admitted with severe psychotic symptoms and started on a rapid titration of clozapine. During his hospitalization he developed somnolence, fever, and tachycardia with leukocytosis, elevated inflammatory markers, and cardiac biomarkers concerning for clozapine-induced myocarditis. Alternative etiologies were ruled out and CMR was used to confirm the diagnosis. The patient's symptoms resolved following discontinuation of clozapine and initiation of supportive therapies. CONCLUSIONS Clozapine-induced myocarditis is challenging to diagnose due to a lack of consensus on diagnostic criteria, reliance on voluntary reporting, and non-specific presentation. This report highlights that myocarditis can be associated with clozapine pharmacotherapy in patients with schizophrenia and demonstrates the value of diagnosis using non-invasive CMR. Additional studies are needed to understand the mechanism of clozapine-induced myocarditis and how clozapine titration may affect risk.


Assuntos
Antipsicóticos , Clozapina , Miocardite , Esquizofrenia , Adulto , Antipsicóticos/efeitos adversos , Clozapina/efeitos adversos , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Miocardite/induzido quimicamente , Esquizofrenia/tratamento farmacológico
19.
Nat Commun ; 12(1): 2964, 2021 05 20.
Artigo em Inglês | MEDLINE | ID: mdl-34016980

RESUMO

Knowledge of the structure of amorphous solids can direct, for example, the optimization of pharmaceutical formulations, but atomic-level structure determination in amorphous molecular solids has so far not been possible. Solid-state nuclear magnetic resonance (NMR) is among the most popular methods to characterize amorphous materials, and molecular dynamics (MD) simulations can help describe the structure of disordered materials. However, directly relating MD to NMR experiments in molecular solids has been out of reach until now because of the large size of these simulations. Here, using a machine learning model of chemical shifts, we determine the atomic-level structure of the hydrated amorphous drug AZD5718 by combining dynamic nuclear polarization-enhanced solid-state NMR experiments with predicted chemical shifts for MD simulations of large systems. From these amorphous structures we then identify H-bonding motifs and relate them to local intermolecular complex formation energies.


Assuntos
Química Farmacêutica/métodos , Espectroscopia de Ressonância Magnética , Pirazóis/química , Cristalografia/métodos , Ligação de Hidrogênio , Simulação de Dinâmica Molecular , Estrutura Molecular
20.
Int J Cardiol ; 334: 154-156, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33932426

RESUMO

BACKGROUND: Mitral annular disjunction (MAD) is an increasingly recognized entity associated with mitral valve prolapse (MVP), ventricular arrhythmias and death. Few studies have investigated the utility of myocardial deformation analysis in MAD. We compared chamber quantification including strain by transthoracic echocardiography (TTE) and cardiac magnetic resonance imaging (CMR) between MVP patients with and without MAD. METHODS: Forty-two patients with MVP (21 with MAD, 21 without MAD) and 21 controls were studied. Global, basal and basal inferolateral (BIL) segmental strains were measured and compared using velocity-vector imaging TTE and feature-tracking CMR. RESULTS: Mean age was 54 ± 17 years, 19 (46%) were female, and 19 (46%) underwent surgical mitral valve repair with no deaths during follow-up in the 2 groups with MVP. Patients with MAD and MVP had lower basal longitudinal strain by TTE than those with MVP without MAD. Those with MAD and MVP had lower magnitude in BIL and basal segments by circumferential and radial strain by CMR compared to those with MVP without MAD and controls. Amongst global strain parameters, CMR-derived global circumferential strain was independently associated with MAD diagnosis odds ratio 1.49 (per 1%), 95% confidence interval 1.09-2.05, P = 0.014, with optimal threshold of -18.0% having 76% sensitivity and specificity for MAD. CONCLUSION: Abnormal circumferential and radial strain patterns in the basal segments by CMR may be useful for identifying regional LV dysfunction associated with MAD.


Assuntos
Prolapso da Valva Mitral , Valva Mitral , Adulto , Idoso , Estudos de Casos e Controles , Ecocardiografia , Feminino , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Valva Mitral/diagnóstico por imagem , Valva Mitral/cirurgia , Prolapso da Valva Mitral/diagnóstico por imagem
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