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1.
Mol Cell ; 83(23): 4370-4385.e9, 2023 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-38016475

RESUMO

Targeting epigenetic regulators to potentiate anti-PD-1 immunotherapy converges on the activation of type I interferon (IFN-I) response, mimicking cellular response to viral infection, but how its strength and duration are regulated to impact combination therapy efficacy remains largely unknown. Here, we show that mitochondrial CPT1A downregulation following viral infection restrains, while its induction by epigenetic perturbations sustains, a double-stranded RNA-activated IFN-I response. Mechanistically, CPT1A recruits the endoplasmic reticulum-localized ZDHHC4 to catalyze MAVS Cys79-palmitoylation, which promotes MAVS stabilization and activation by inhibiting K48- but facilitating K63-linked ubiquitination. Further elevation of CPT1A incrementally increases MAVS palmitoylation and amplifies the IFN-I response, which enhances control of viral infection and epigenetic perturbation-induced antitumor immunity. Moreover, CPT1A chemical inducers augment the therapeutic effect of combined epigenetic treatment with PD-1 blockade in refractory tumors. Our study identifies CPT1A as a stabilizer of MAVS activation, and its link to epigenetic perturbation can be exploited for cancer immunotherapy.


Assuntos
Interferon Tipo I , Viroses , Humanos , Transdução de Sinais , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Lipoilação , Epigênese Genética , Imunidade Inata
2.
Eur J Nutr ; 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38869657

RESUMO

PURPOSE: Our study aimed to explore the efficacy of Bifidobacterium breve 207-1 on specific neurotransmitters and hormones and the ability to regulate lifestyle behaviors in healthy adults. METHODS: In total, 120 healthy adults with high mental stress, overweight, insomnia, and constipation were randomly assigned to receive low-dose B. breve 207-1 (LD, n = 40), high-dose B. breve 207-1 (HD, n = 40), or placebo (n = 40) for 28 days. Fecal and blood samples were collected and questionnaires were answered before and after the trial. Neurotransmitters and serum hormones were detected using enzyme-linked immunosorbent assay. The gut microbiota composition was assessed using 16 S rRNA sequencing. Short-chain fatty acids (SCFAs) concentrations were determined via gas chromatography-mass spectrometry (GC-MS). RESULTS: The primary outcome of our study was changes in mental wellness, including neurotransmitters, the hypothalamic-pituitary-adrena (HPA) axis hormones, and the psychological scales. The results showed that γ-aminobutyric acid (GABA) increased significantly and the HPA axis hormones were suppressed overall in the probiotic groups while 5-hydroxytryptamine (5-HT) did not change significantly. However, there was no significant change in mood scale scores. The secondary outcome focused on the ability of 207-1 to regulate the body and lifestyle of healthy adults (e.g., sleep, diet, exercise, etc.). The PSQI scores in the probiotics groups significantly decreased, indicating improved sleep quality. Meanwhile, the probiotic groups had a slight increase in exercise consumption while dietary intake stabilized. By physical examination, the participants showed weight loss although no statistically significant difference was observed between the groups. Then, validated by gut microbiota, changes in the gut microbiota were observed under the effective intervention of 207-1 while short-chain fatty acids (SCFAs) increased in the LD group, particularly acetic and propionic acids. There was a slight decrease in alpha-diversity in the HD group. CONCLUSION: Bifidobacterium breve 207-1 entered the organism and affected neurotransmitter and the HPA axis hormone levels via the microbiome-gut-brain axis. Meanwhile, 207-1 supplementation improved daily lifestyle behaviors in healthy adults, which may in turn lead to changes in their bodies (e.g. weight and lipid metabolism). However, this study did not find significant mood-modulating efficacy. The mechanism of the overall study is unclear, but we hypothesize that SCFAs may be the key pathway, and more experiments are needed for validation in the future. TRIAL REGISTRATION: This trial was retrospectively registered in the Chinese Clinical Trial Registry under the accession number ChiCTR2300069453 on March 16, 2023.

3.
Part Fibre Toxicol ; 21(1): 21, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38658944

RESUMO

BACKGROUND: Increasing attention is being paid to the environmental and health impacts of nanoplastics (NPs) pollution. Exposure to nanoplastics (NPs) with different charges and functional groups may have different adverse effects after ingestion by organisms, yet the potential ramifications on mammalian blood glucose levels, and the risk of diabetes remain unexplored. RESULTS: Mice were exposed to PS-NPs/COOH/NH2 at a dose of 5 mg/kg/day for nine weeks, either alone or in a T2DM model. The findings demonstrated that exposure to PS-NPs modified by different functional groups caused a notable rise in fasting blood glucose (FBG) levels, glucose intolerance, and insulin resistance in a mouse model of T2DM. Exposure to PS-NPs-NH2 alone can also lead the above effects to a certain degree. PS-NPs exposure could induce glycogen accumulation and hepatocellular edema, as well as injury to the pancreas. Comparing the effect of different functional groups or charges on T2DM, the PS-NPs-NH2 group exhibited the most significant FBG elevation, glycogen accumulation, and insulin resistance. The phosphorylation of AKT and FoxO1 was found to be inhibited by PS-NPs exposure. Treatment with SC79, the selective AKT activator was shown to effectively rescue this process and attenuate T2DM like lesions. CONCLUSIONS: Exposure to PS-NPs with different functional groups (charges) induced T2DM-like lesions. Amino-modified PS-NPs cause more serious T2DM-like lesions than pristine PS-NPs or carboxyl functionalized PS-NPs. The underlying mechanisms involved the inhibition of P-AKT/P-FoxO1. This study highlights the potential risk of NPs pollution on T2DM, and provides a new perspective for evaluating the impact of plastics aging.


Assuntos
Glicemia , Diabetes Mellitus Tipo 2 , Resistência à Insulina , Nanopartículas , Poliestirenos , Proteínas Proto-Oncogênicas c-akt , Animais , Diabetes Mellitus Tipo 2/induzido quimicamente , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Masculino , Poliestirenos/toxicidade , Poliestirenos/química , Nanopartículas/toxicidade , Proteínas Proto-Oncogênicas c-akt/metabolismo , Diabetes Mellitus Experimental/induzido quimicamente , Camundongos , Proteína Forkhead Box O1/metabolismo , Microplásticos/toxicidade , Fosforilação , Camundongos Endogâmicos C57BL , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia
4.
J Oral Maxillofac Surg ; 82(5): 590-594, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38341184

RESUMO

Teratomas are congenital malformations that rarely occur in the oral cavity. In the case reported here, fetal magnetic resonance imaging performed at 30 weeks of gestation informed the decision-making of the multidisciplinary management team, who closely followed the pregnancy until the scheduled cesarean delivery at 38 weeks of gestation. After delivery, tracheal intubation was performed to ensure airway patency, and tumor resection was scheduled immediately after ruling out contraindications to surgery based on preoperative examinations, allowing for safe excising of the tumor. Postoperative follow-up at 3 months showed no abnormalities.


Assuntos
Imageamento por Ressonância Magnética , Neoplasias Bucais , Teratoma , Humanos , Teratoma/congênito , Teratoma/cirurgia , Teratoma/diagnóstico por imagem , Teratoma/diagnóstico , Feminino , Gravidez , Recém-Nascido , Neoplasias Bucais/cirurgia , Neoplasias Bucais/congênito , Neoplasias Bucais/diagnóstico por imagem , Neoplasias Bucais/diagnóstico , Adulto , Diagnóstico Pré-Natal
5.
Thromb J ; 21(1): 64, 2023 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-37280671

RESUMO

BACKGROUND: The incidence of incidental pulmonary embolism (IPE) has greatly increased, but its clinical characteristics and outcomes are still controversial. This study aimed to compare the clinical characteristics and outcomes between cancer patients with IPE and patients with symptomatic pulmonary embolism (SPE). PATIENTS/METHODS: Clinical data of 180 consecutive patients with cancer complicated with pulmonary embolism admitted to Beijing Cancer Hospital from July 2011 to December 2019 were retrospectively collected and analysed. General characteristics, diagnosis time of pulmonary embolism (PE), location of PE, concurrent deep venous thrombosis, anticoagulant treatment, impact of PE on anti-tumor treatment, recurrent venous thromboembolism, rate of bleeding after anticoagulation therapy, survival and risk factors of IPE were compared with SPE. RESULTS: Of 180 patients, 88 (49%) had IPEs and 92 (51%) had SPEs. Patients with IPE and SPE did not differ in age, sex, tumor type, or tumor stage. Median diagnosis times of IPE and SPE after cancer were 108 (45, 432) days and 90 (7, 383) days, respectively. Compared to SPE, IPE tended to be central (44% versus 26%; P < 0.001), isolated (31.8% versus 0.0%; P < 0.001), and unilateral (67.1% versus 12.8%; P < 0.00). The rate of bleeding after anticoagulation therapy did not differ between IPE and SPE. Patients with IPE had a better prognosis than patients with SPE in terms of 30-, and 90-day mortality, as well as overall survival after diagnosis of PE (median: 314.5 vs. 192.0 days, log-rank P = 0.004) and cancer (median: 630.0 vs. 450.5 days, log-rank P = 0.018). SPE (compared to IPE) was an independent risk factor for poor survival after diagnosis of PE in multivariate analysis (hazard ratio [HR] = 1.564, 95% confidence interval [CI]: 1.008-2.425, p = 0.046). CONCLUSIONS: IPE accounts for nearly one half of PE cases among Chinese cancer patients. With active anticoagulation treatment, IPE is expected to achieve better survival rates than SPE.

6.
Anal Bioanal Chem ; 415(27): 6733-6742, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37740753

RESUMO

Non-invasive blood composition analysis based on dynamic spectrum (DS) theory has gained significant attention due to its non-invasive, simple, and fast performance. However, most of the multi-wavelength photoplethysmography (PPG) detection devices used to obtain DS are composed of halogen light sources and spectrometers and cannot detect effective PPG signals in the visible light short band (400-620 nm), which limits the detection accuracy of blood components with significant absorption spectral differences in that band. Therefore, this paper designs a multi-wavelength spectral acquisition system that can measure high signal-to-noise ratio (SNR > 65 dB) PGG signals at wavelengths of 405, 430, 450, 505, 520, and 570 nm and combines this system with a halogen lamp spectrometer acquisition system for non-invasive blood component detection. Furthermore, this paper collects the DS of 272 subjects with the combined system and establishes a predictive model for DS with the content of red blood cell (RBC) and hemoglobin (HGB) components. The results show that, compared with the halogen lamp spectrometer acquisition system, the correlation coefficient (Rp) of RBC and HGB prediction model established by the combined system has increased by 0.0619 and 0.0489, respectively, and the root mean square error (RMSE) has decreased by 0.08 1e12/L and 0.85 g/L, which confirm the feasibility of the designed multi-wavelength spectrum acquisition system to enhance the accuracy of blood component detection.

7.
Magn Reson Chem ; 61(3): 169-179, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36349476

RESUMO

The recently reported 19 F-detected dual-optimized inverted 1 JCC 1,n-ADEQUATE experiment and the previously reported 1 H-detected version have been modified to incorporate J-modulation, making it feasible to acquire all 1,1- and 1,n-ADEQUATE correlations as well as 1 JCC and n JCC homonuclear scalar couplings in a single experiment. The experiments are demonstrated using N,N-dimethylamino-2,5,6-trifluoro-3,4-phthalonitrile and N,N-dimethylamino-3,4-phthalonitrile.

8.
J Clin Pediatr Dent ; 47(5): 176-180, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37732452

RESUMO

Regional odontodysplasia (RO) is a rare developmental abnormality of epithelial and mesenchymal dental tissues. Due to its poorly understood etiology, assessing and discussing related clinical cases of this dental anomaly is crucial to guide professionals in improving its treatment and outcomes. This article aimed to report the case of a 9-year-old male patient who presented to our department with the main complaint of absent eruption of permanent left mandibular quadrant teeth. This is the first case reported in China from a patient with multiple cutaneous nevi on the face and neck, and based on the retrieved clinical and radiographic features, we described and discussed the treatment and etiology of RO.


Assuntos
Odontodisplasia , Masculino , Humanos , Criança , Odontodisplasia/diagnóstico por imagem , Pescoço , Mandíbula , Erupção Dentária
9.
Psychol Med ; 51(10): 1742-1751, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-32178746

RESUMO

BACKGROUND: Social anxiety disorder (SAD) is a prevalent mental disorder diagnosed in childhood and adolescence. Theories regarding brain development and SAD suggest a close link between neurodevelopmental dysfunction at the adolescent juncture and SAD, but direct evidence is rare. This study aims to examine brain structural abnormalities in adolescents with SAD. METHODS: High-resolution T1-weighted images were obtained from 31 adolescents with SAD (15-17 years) and 42 matching healthy controls (HC). We evaluated symptom severity with the Social Anxiety Scale for Children (SASC) and the Screen for Child Anxiety Related Emotional Disorders (SCARED). We used voxel-based morphometry analysis to detect regional gray matter volume abnormalities and structural co-variance analysis to investigate inter-regional coordination patterns. RESULTS: We found significantly higher gray matter volume in the orbitofrontal cortex (OFC) and the insula in adolescents with SAD compared to HC. We also observed significant co-variance of the gray matter volume between the OFC and amygdala, and the OFC and insula in HC, but these co-variance relationships diminished in SAD. CONCLUSIONS: These findings provide the first evidence that the brain structural deficits in adolescents with SAD are not only in the core regions of the fronto-limbic system, but also represented by the diminished coordination in the development of these regions. The delayed and unsynchronized development pattern of the fronto-limbic system supports SAD as an adolescent-sensitive developmental mental disorder.


Assuntos
Substância Cinzenta/fisiopatologia , Processamento de Imagem Assistida por Computador , Sistema Límbico/fisiopatologia , Fobia Social/epidemiologia , Adolescente , Encéfalo/fisiopatologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Fatores Socioeconômicos
10.
Sensors (Basel) ; 21(4)2021 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-33567621

RESUMO

According to the experience of nurses and physiotherapists, the abdomen of constipated people becomes softer after abdominal massage. However, the relationship between the decrease in abdominal stiffness and the benefits of abdominal massage has not been examined quantitatively and is unclear. Furthermore, devices for measuring stiffness have been designed to measure relatively hard areas such as the shoulders and do not take into account the lateral outflow of the target tissue, which can be a problem when measuring the stiffness of soft areas such as the abdomen. To address these issues, this study presents a stiffness sensor suitable for measuring abdominal stiffness and investigates the relationship between the reduction in abdominal stiffness and the benefits of abdominal massage. The solution to prevent the lateral outflow of the target is the realization of a stopper, including a contact detection device, which enables a wide-area contact around the targeted area. The sensor consists of a stopper, probe, spring, and time-of-flight (ToF) sensors. The probe and spring provide appropriate pressure and deformation to the abdomen, whereas the stopper prevents the probe from being pushed into the abdomen more than necessary. The ToF sensor measures the deformation length when the deformation is stopped by the stopper. The abdominal stiffness can be derived from the deformation length. The investigation results indicate that the reduction in abdominal stiffness corresponds to the improvement of the stool condition or the maintenance of a healthy stool condition, whereas the maintenance of abdominal stiffness indicates the maintenance or deterioration of the stool condition.


Assuntos
Constipação Intestinal , Massagem , Abdome/fisiologia , Constipação Intestinal/diagnóstico , Humanos , Dispositivos Eletrônicos Vestíveis
11.
Hu Li Za Zhi ; 68(4): 32-42, 2021 Aug.
Artigo em Zh | MEDLINE | ID: mdl-34337701

RESUMO

BACKGROUND: Supportive care is a primary method for treating dengue fever. Understanding the symptoms of dengue fever and its related nursing diagnosis is crucial for nurses as references for individual care. This research study was motivated by the few literature reviews available on this topic. PURPOSE: This study was developed to elucidate the symptoms experienced by hospitalized patients with dengue fever and to compare the consistency between symptoms and nursing diagnoses. METHODS: A retrospective descriptive research method was employed. The data were collected from the electronic medical records of patients in the data pools of two regional hospitals in Kaohsiung City. A total of 105 patient records were acquired covering the period 2014-2016. IBM SPSS Statistics v22 was used to examine the descriptive statistics of patient attributes and symptoms of dengue fever using averages and percentages and the inferential statistics of symptoms, hospitalization days, and nursing diagnosis using the Chi-square test and Kappa consistency coefficient. RESULTS: The average age of inpatients was 51.0 ± 27.3 years and the average length of hospital stays was 6.1 ± 3.6 days. The common symptoms were fever and headache. The consistency between nursing diagnosis and symptoms ranged up to 45.4%, including hyperthermia, acute pain, nausea, risk of ineffective gastrointestinal perfusion, and risk of bleeding. Inconsistency of nursing diagnosis was found to be 27.3%, including anxiety, deficient fluid volume, and risk of falls. The rate of undiagnosed symptoms was found to be 27.3%, including diarrhea, risk of infection, and impaired oral mucous membrane. CONCLUSIONS / IMPLICATIONS FOR PRACTICE: The reasons for the inconsistency between symptoms and nursing diagnoses may relate to insufficient nursing knowledge of dengue fever and inadequate nursing diagnosis education resulting in insufficient clinical experience / poor judgment amongst nursing staff. The findings of this study suggest the need for continuity of education to make the use of a dengue-fever-symptom checklist more widespread in patient care.


Assuntos
Dengue , Diagnóstico de Enfermagem , Adulto , Idoso , Dengue/diagnóstico , Febre/diagnóstico , Hospitalização , Humanos , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
12.
Angew Chem Int Ed Engl ; 60(45): 24018-24021, 2021 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-34468077

RESUMO

Nuclear spin relaxation dispersion parameters are proposed as indicators of the binding mode of a ligand to a protein. Hyperpolarization by dissolution dynamic nuclear polarization (D-DNP) provided a 13 C signal enhancement between 3000-6000 for the ligand 4-(trifluoromethyl) benzene-1-carboximidamide binding to trypsin. The measurement of 13 C R2 relaxation dispersion was enabled without isotope enrichment, using a series of single-scan Carr-Purcell-Meiboom-Gill experiments with variable refocusing delays. The magnitude in dispersion for the spins of the ligand is correlated to the position with respect to the salt bridge between protein and the amidine group of the ligand, indicating the ligand binding orientation. Hyperpolarized relaxation dispersion is an alternative to chemical shift or NOE measurements for determining ligand binding modes.


Assuntos
Oximas/química , Tripsina/química , Sítios de Ligação , Isótopos de Carbono , Ligantes , Estrutura Molecular
13.
Anal Chem ; 92(20): 13718-13723, 2020 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-32897681

RESUMO

Immobilization of a target protein enhances the cross-relaxation rates for transfer of nuclear spin polarization but reduces the accessible target concentration. Hyperpolarization of ligand spins by dissolution dynamic nuclear polarization (D-DNP) is shown to increase sensitivity for observing the intraligand nuclear Overhauser effect (NOE). This effect, also known as the transferred NOE (trNOE), can be used for detection of binding and for obtaining binding-related structural information. The measurement of hyperpolarized trNOE signals is demonstrated for the ligand 4'-hydroxyazobenzene-2-carboxylic acid interacting with avidin protein immobilized on polystyrene beads. In a sample containing 63.5 µM ligands and 0.83 µM accessible protein binding sites, the signal enhancement provided by D-DNP leads to single-scan detection of the NOE buildup, despite that this signal peaks at only 2% of the total ligand signal. These buildup curves allow the confirmation of binding through a change in the sign of the NOE and the quantitative determination of cross-relaxation rates. The combination of the D-DNP technique and protein immobilization may facilitate the identification of intraligand NOEs in ligand screening for drug discovery. The same method may be applied to in vivo characterization of ligand interactions with cell surface proteins.


Assuntos
Ligantes , Ressonância Magnética Nuclear Biomolecular/métodos , Proteínas/química , Proteínas Imobilizadas/química , Poliestirenos/química , Ligação Proteica , Proteínas/metabolismo
14.
Anal Bioanal Chem ; 412(7): 1611-1618, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31965246

RESUMO

Mammography, a standard screening method for breast cancer, is effective for reducing the rate of death; however, it suffers from frequent false positive alarm and radiation risk. Besides, surgery treatment has a vital impact on the clinical outcomes of breast cancer, offering enormous benefits for breast cancer care and management. In this work, we analyzed the peripheral blood sample from breast cancer patients with pre- and post-surgery and healthy volunteers using label-free surface-enhanced Raman spectroscopy technology based on silver nanoparticles. Results showed that distinct patterns of blood belonging to specific subjects could be profiled, and corresponding accuracies of 95% and 100% were achieved by multivariate diagnostic algorithm for pre-surgery vs. post-surgery and pre-surgery vs. normal groups, respectively, providing a unique blood analysis method for surgery evaluation as well as tumor screening in breast cancer. Graphical abstract.


Assuntos
Neoplasias da Mama/sangue , Neoplasias da Mama/diagnóstico , Análise Espectral Raman/métodos , Neoplasias da Mama/cirurgia , Detecção Precoce de Câncer , Feminino , Humanos , Programas de Rastreamento , Nanopartículas Metálicas/química , Pessoa de Meia-Idade , Análise de Componente Principal , Sensibilidade e Especificidade , Prata/química
15.
Perception ; 49(12): 1311-1332, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33302776

RESUMO

Wet fabric clinging to human skin may cause stickiness perception and facilitate wearing discomfort. This study aims to investigate the stickiness perception of wet fabrics via two contact modes (friction and adhesion-separation) as well as the influences of fabric properties and contact features on stickiness perception. A set of dynamic contact devices was developed to drive the samples to move horizontally or vertically on volar forearms. According to the magnitude estimation approach, 12 subjects were asked to assess the stickiness perceptions caused by 64 types of contact stimuli. The results showed that the water absorption capacity had a significant and negative correlation with stickiness perception under the two contact modes. However, the surface roughness was neither related to stickiness perception under the friction mode nor to stickiness perception under the adhesion-separation mode. There was an interaction between contact pressure and sliding velocity. The sliding velocity at medium or high pressure had a significant effect on stickiness perception, but the separating velocity had no significant effect. Stickiness perception under the friction mode is higher than that under the adhesion-separation mode in most cases. Consequently, the friction mode was considered the main contact mode that evokes stickiness perception.


Assuntos
Antebraço , Têxteis , Fricção , Humanos , Percepção , Pele
16.
Methods ; 138-139: 69-75, 2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29471063

RESUMO

The nuclear Overhauser effect (NOE) is a primary means to characterize intermolecular interactions using modern NMR spectroscopy. Multiple experiments measured using different mixing time can be used for quantifying NOE buildup and measuring cross-relaxation rates. However, this approach using conventional multi-dimensional NMR is time consuming. Hyperpolarization by dissolution dynamic nuclear polarization (D-DNP) can generate deviations from equilibrium spin polarization by orders of magnitude, thereby enhancing signals and allowing to characterize NOE build up in real-time. Since most small molecules can be hyperpolarized using D-DNP, this method is applicable to the study of intermolecular interactions between small molecules and macromolecules. This application is demonstrated using a model system for host-guest interactions including the third generation polyamidoamine dendrimer (G3 PAMAM) and the pharmaceutical phenylbutazone (PBZ). After mixing 1H hyperpolarized PBZ with PAMAM, the NOE build up is directly observed at different sites of the dendrimer in series of one-dimensional NMR spectra. Cross-relaxation rates specific to individual source and target spins are determined from the build up curves. Further, the polarization enhancement is shown to be sufficiently large to allow identification of cross-peaks not observed in a conventional 2D-NOESY spectrum. The improved signal-to-noise ratio provided by hyperpolarization allows for characterizing the intermolecular interaction in an almost instantaneous measurement, opening an application to macromolecular and biomacromolecular NMR.


Assuntos
Dendrímeros/química , Espectroscopia de Ressonância Magnética , Fenilbutazona/química , Poliaminas/química , Dendrímeros/análise
17.
J Biomol NMR ; 65(1): 41-8, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27189223

RESUMO

Protein-ligand interaction is often characterized using polarization transfer by the intermolecular nuclear Overhauser effect (NOE). For such NOE experiments, hyperpolarization of nuclear spins presents the opportunity to increase the spin magnetization, which is transferred, by several orders of magnitude. Here, folic acid, a ligand of dihydrofolate reductase (DHFR), was hyperpolarized on (1)H spins using dissolution dynamic nuclear polarization (D-DNP). Mixing hyperpolarized ligand with protein resulted in observable increases in protein (1)H signal predominantly in the methyl group region of the spectra. Using (13)C single quantum selection in a series of one-dimensional spectra, the carbon chemical shift ranges of the corresponding methyl groups can be elucidated. Signals observed in these hyperpolarized spectra could be confirmed using 3D isotope filtered NOESY spectra, although the hyperpolarized spectra were obtained in single scans. By further correlating the signal intensities observed in the D-DNP experiments with the occurrence of short distances in the crystal structure of the protein-ligand complex, the observed methyl proton signals could be matched to the chemical shifts of six amino acids in the active site of DHFR-folic acid binary complex. These data demonstrate that (13)C chemical shift selection of protein resonances, combined with the intrinsic selectivity towards magnetization originating from the initially hyperpolarized spins, can be used for site specific characterization of protein-ligand interactions.


Assuntos
Ligantes , Ressonância Magnética Nuclear Biomolecular , Tetra-Hidrofolato Desidrogenase/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Modelos Moleculares , Conformação Molecular , Ligação Proteica , Espectroscopia de Prótons por Ressonância Magnética
18.
BMC Cancer ; 16: 454, 2016 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-27405731

RESUMO

BACKGROUND: The PIK3CA (H1047R) mutation is considered to be a potential predictive biomarker for EGFR-targeted therapies. In this study, we developed a novel PCR-PFLP approach to detect the PIK3CA (H1047R) mutation in high effectiveness. METHODS: A 126-bp fragment of PIK3CA exon-20 was amplified by PCR, digested with FspI restriction endonuclease and separated by 3 % agarose gel electrophoresis for the PCR-RFLP analysis. The mutant sequence of the PIK3CA (H1047R) was spiked into the corresponding wild-type sequence in decreasing ratios for sensitivity analysis. Eight-six cases of formalin-fixed paraffin-embedded colorectal cancer (CRC) specimens were subjected to PCR-RFLP to evaluate the applicability of the method. RESULTS: The PCR-RFLP method had a capability to detect as litter as 0.4 % of mutation, and revealed 16.3 % of the PIK3CA (H1047R) mutation in 86 CRC tissues, which was significantly higher than that discovered by DNA sequencing (9.3 %). A positive association between the PIK3CA (H1047R) mutation and the patients' age was first found, except for the negative relationship with the degree of tumor differentiation. In addition, the highly sensitive detection of a combinatorial mutation of PIK3CA, KRAS and BRAF was achieved using individual PCR-RFLP methods. CONCLUSIONS: We developed a sensitive, simple and rapid approach to detect the low-abundance PIK3CA (H1047R) mutation in real CRC specimens, providing an effective tool for guiding cancer targeted therapy.


Assuntos
Classe I de Fosfatidilinositol 3-Quinases/genética , Neoplasias Colorretais/genética , Reação em Cadeia da Polimerase/métodos , Polimorfismo de Fragmento de Restrição/genética , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Fatores Etários , Biomarcadores Tumorais/genética , Linhagem Celular Tumoral , Neoplasias Colorretais/patologia , Análise Mutacional de DNA/métodos , Feminino , Células HT29 , Humanos , Masculino , Pessoa de Meia-Idade
20.
Anal Chem ; 86(6): 3216-21, 2014 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-24568176

RESUMO

A fast and sensitive assay of protease activity on a micro/nanofluidics preconcentrator combining with fluorescence resonance energy transfer (FRET) detection technique has been developed in a homogeneous real-time format. First, the functionalized nanoprobes are formed by loading dye labeled protein onto gold nanoparticles (AuNPs), in which, the photoluminescence of donor dye was strongly quenched by AuNPs due to FRET mechanisms. For protease activity assay, the nanoprobes are enriched by a micro/nanofluidics preconcentrator. When the target protease is transported to the enriched nanoprobes, cleavage of protein occurs as a consequence of molecular recognition of enzyme to substrate. The release of cleavage fragments from AuNPs nanoprobes leads to the enhancement of fluorescence and enables the protease activity assay on the micro/nanofluidics chip. As a demonstration, digestion of fluorescein isothiocyanate labeled dog serum albumin (FITC-DSA) by trypsin was used as a model reaction. Because of the highly efficient preconcentration and space confinement effect, significantly increased protein cleavage rate and protease assay sensitivity can be achieved with enhanced enzyme activity. The present micro/nanofluidics platform fused with the FRET detection technique is promising for fast and sensitive bioanalysis such as immunoassay, DNA hybridization, drug discovery, and clinical diagnosis.


Assuntos
Transferência Ressonante de Energia de Fluorescência/instrumentação , Microfluídica , Peptídeo Hidrolases/metabolismo , Microfluídica/instrumentação
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