RESUMO
OBJECTIVES: Osteoarthritis (OA) features ageing-related defects in cellular homeostasis mechanisms in articular cartilage. These defects are associated with suppression of forkhead box O (FoxO) transcription factors. FoxO1 or FoxO3 deficient mice show early onset OA while FoxO1 protects against oxidative stress in chondrocytes and promotes expression of autophagy genes and the essential joint lubricant proteoglycan 4 (PRG4). The objective of this study was to identify small molecules that can increase FoxO1 expression. METHODS: We constructed a reporter cell line with FoxO1 promoter sequences and performed high-throughput screening (HTS) of the Repurposing, Focused Rescue and Accelerated Medchem (ReFRAME) library . Hits from the HTS were validated and function was assessed in human chondrocytes, meniscus cells and synoviocytes and following administration to mice. The most promising hit, the histone deacetylase inhibitor (HDACI) panobinostat was tested in a murine OA model. RESULTS: Among the top hits were HDACI and testing in human chondrocytes, meniscus cells and synoviocytes showed that panobinostat was the most promising compound as it increased the expression of autophagy genes and PRG4 while suppressing the basal and IL-1ß induced expression of inflammatory mediators and extracellular matrix degrading enzymes. Intraperitoneal administration of panobinostat also suppressed the expression of mediators of OA pathogenesis induced by intra-articular injection of IL-1ß. In a murine OA model, panobinostat reduced the severity of histological changes in cartilage, synovium and subchondral bone and improved pain behaviours. CONCLUSION: Panobinostat has a clinically relevant activity profile and is a candidate for OA symptom and structure modification.
Assuntos
Cartilagem Articular , Osteoartrite , Humanos , Camundongos , Animais , Fatores de Transcrição Forkhead , Inibidores de Histona Desacetilases/metabolismo , Panobinostat/metabolismo , Osteoartrite/patologia , Envelhecimento , Condrócitos/metabolismo , Cartilagem Articular/metabolismo , Interleucina-1beta/metabolismoRESUMO
Noncoding RNAs are key regulators in the Warburg Effect, an emerging hallmark of cancer. We intended to investigate the role and mechanism of circular RNA hsa_circ_0052611 (circ_0052611) and microRNA (miR)-767-5p in breast cancer (BRCA) hallmarks, especially the Warburg Effect. Expression of circ_0052611 and SCAI was downregulated, and miR-767-5p was upregulated in human BRCA tissues and cells; moreover, circ_0052611 acted as a miR-767-5p sponge to modulate the expression of miR-767-5p-targeted SCAI. Functionally, re-expressing circ_0052611 suppressed migration, invasion, glucose uptake, lactate production, and extracellular acidification rate (ECAR) in BRCA cells, and promoted apoptotic rate. These effects were accompanied by decreased Vimentin, N-cadherin, Bcl-2, and LDHA, and increased E-cadherin and Bax. Consistently, exhausting miR-767-5p exerted similar effects in BRCA cells. High miR-767-5p could counteract the role of circ_0052611 overexpression, and low SCAI likewise blocked the role of miR-767-5p deletion. In vivo, upregulating circ_0052611 delayed tumor growth of BRCA cells by altering miR-767-5p and SCAI expression. circ_0052611/miR-767-5p/SCAI axis might boycott the malignancy of BRCA cells.
Assuntos
Caderinas , MicroRNAs , Humanos , Transporte Biológico , Linhagem Celular Tumoral , Proliferação de Células , Ácido Láctico , MicroRNAs/genética , RNA Circular/genéticaRESUMO
Circular RNA (circRNA) regulates malignant tumors, including ovarian cancer (OC). The present research study aimed to reveal the biological mechanism of circRNA mitofusin 2 (circMFN2) in OC. Cell biological behaviors were investigated using clonogenicity assay, EdU assay, transwell assay, and flow cytometry analysis. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and western blot analysis were implemented to detect the levels of circMFN2, miR-198, Cullin 4B (CUL4B), and apoptosis-related proteins. Glycolysis was assessed by glucose assay kit, lactate assay kit, and ATP level detection kit. The relationships among miR-198, circMFN2, and CUL4B were verified by dual-luciferase reporter assay and RNA immunoprecipitation assay. The xenograft mice model was used to analyze tumor growth in vivo. The expression of circMFN2 and CUL4B was increased, while miR-330-5p was decreased in OC tissues or cells. The absence of CircMFN2 hindered cell proliferation, migration, invasion, and glycolysis and promoted apoptosis in OC cells. We found that circMFN2 promoted CUL4B expression via sponging miR-198. MiR-198 depletion reversed circMFN2 knockdown-induced effects in OC cells. Furthermore, CUL4B overexpression overturned the inhibitory effect of miR-198 in OC cells. And the absence of circMFN2 inhibited tumor growth in vivo. CircMFN2 repressed OC progression by regulating the miR-198/CUL4B axis.
Assuntos
MicroRNAs , Neoplasias Ovarianas , Humanos , Animais , Camundongos , Feminino , RNA Circular/genética , Neoplasias Ovarianas/genética , Glicólise , Proliferação de Células , Modelos Animais de Doenças , Ácido Láctico , MicroRNAs/genética , Linhagem Celular Tumoral , Proteínas Culina/genéticaRESUMO
In immunoglobulin light chain (LC) amyloidosis, the misfolding, or misfolding and misassembly of LC a protein or fragments thereof resulting from aberrant endoproteolysis, causes organ damage to patients. A small molecule "kinetic stabilizer" drug could slow or stop these processes and improve prognosis. We previously identified coumarin-based kinetic stabilizers of LCs that can be divided into four components, including a "linker module" and "distal substructure". Our prior studies focused on characterizing carbamate, hydantoin, and spirocyclic urea linker modules, which bind in a solvent-exposed site at the VL-VL domain interface of the LC dimer. Here, we report structure-activity relationship data on 7-diethylamino coumarin-based kinetic stabilizers. This substructure occupies the previously characterized "anchor cavity" and the "aromatic slit". The potencies of amide and urea linker modules terminating in a variety of distal substructures attached at the 3-position of this coumarin ring were assessed. Surprisingly, crystallographic data on a 7-diethylamino coumarin-based kinetic stabilizer reveals that the urea linker module and distal substructure attached at the 3-position bind a solvent-exposed region of the full-length LC dimer distinct from previously characterized sites. Our results further elaborate the small-molecule binding surface of LCs that could be occupied by potent and selective LC kinetic stabilizers.
Assuntos
Cumarínicos/farmacologia , Cadeias Leves de Imunoglobulina/química , Ureia/química , Sítios de Ligação/efeitos dos fármacos , Cumarínicos/síntese química , Cumarínicos/química , Relação Dose-Resposta a Droga , Humanos , Cinética , Estrutura Molecular , Estabilidade Proteica , Relação Estrutura-AtividadeRESUMO
The genetics of cortical arealization in youth is not well understood. In this study, we use a genetically informative sample of 677 typically developing children and adolescents (mean age 12.72 years), high-resolution MRI, and quantitative genetic methodology to address several fundamental questions on the genetics of cerebral surface area. We estimate that >85% of the phenotypic variance in total brain surface area in youth is attributable to additive genetic factors. We also observed pronounced regional variability in the genetic influences on surface area, with the most heritable areas seen in primary visual and visual association cortex. A shared global genetic factor strongly influenced large areas of the frontal and temporal cortex, mirroring regions that are the most evolutionarily novel in humans relative to other primates. In contrast to studies on older populations, we observed statistically significant genetic correlations between measures of surface area and cortical thickness (rG = 0.63), suggestive of overlapping genetic influences between these endophenotypes early in life. Finally, we identified strong and highly asymmetric genetically mediated associations between Full-Scale Intelligence Quotient and left perisylvian surface area, particularly receptive language centers. Our findings suggest that spatially complex and temporally dynamic genetic factors are influencing cerebral surface area in our species.SIGNIFICANCE STATEMENT Over evolution, the human cortex has undergone massive expansion. In humans, patterns of neurodevelopmental expansion mirror evolutionary changes. However, there is a sparsity of information on how genetics impacts surface area maturation. Here, we present a systematic analysis of the genetics of cerebral surface area in youth. We confirm prior research that implicates genetics as the dominant force influencing individual differences in global surface area. We also find evidence that evolutionarily novel brain regions share common genetics, that overlapping genetic factors influence both area and thickness in youth, and the presence of strong genetically mediated associations between intelligence and surface area in language centers. These findings further elucidate the complex role that genetics plays in brain development and function.
Assuntos
Córtex Cerebral/diagnóstico por imagem , Lateralidade Funcional/genética , Inteligência/genética , Adolescente , Mapeamento Encefálico , Criança , Feminino , Testes Genéticos , Humanos , Imageamento por Ressonância Magnética , Masculino , Tamanho do Órgão/genética , Gêmeos/genéticaRESUMO
PURPOSE: Simultaneous multislice (SMS) imaging is a useful way to accelerate functional magnetic resonance imaging (fMRI). As acceleration becomes more aggressive, an increasingly larger number of receive coils are required to separate the slices, which significantly increases the computational burden. We propose a coil compression method that works with concentric ring non-Cartesian SMS imaging and should work with Cartesian SMS as well. We evaluate the method on fMRI scans of several subjects and compare it to standard coil compression methods. METHODS: The proposed method uses a slice-separation k-space kernel to simultaneously compress coil data into a set of virtual coils. Five subjects were scanned using both non-SMS fMRI and SMS fMRI with three simultaneous slices. The SMS fMRI scans were processed using the proposed method, along with other conventional methods. Code is available at https://github.com/alcu/sms. RESULTS: The proposed method maintained functional activation with a fewer number of virtual coils than standard SMS coil compression methods. Compression of non-SMS fMRI maintained activation with a slightly lower number of virtual coils than the proposed method, but does not have the acceleration advantages of SMS fMRI. CONCLUSION: The proposed method is a practical way to compress and reconstruct concentric ring SMS data and improves the preservation of functional activation over standard coil compression methods in fMRI. Magn Reson Med 76:1196-1209, 2016. © 2015 Wiley Periodicals, Inc.
Assuntos
Algoritmos , Mapeamento Encefálico/métodos , Encéfalo/fisiologia , Compressão de Dados/métodos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Processamento de Sinais Assistido por Computador , Humanos , Aumento da Imagem/métodos , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
PURPOSE: To identify regional differences in apparent diffusion coefficient (ADC) and fractional anisotropy (FA) using customized preprocessing before voxel-based analysis (VBA) in 14 normal subjects with the specific genes that decrease (apolipoprotein [APO] E ε2) and that increase (APOE ε4) the risk of Alzheimer's disease. MATERIALS AND METHODS: Diffusion tensor images (DTI) acquired at 1.5 Tesla were denoised with a total variation tensor regularization algorithm before affine and nonlinear registration to generate a common reference frame for the image volumes of all subjects. Anisotropic and isotropic smoothing with varying kernel sizes was applied to the aligned data before VBA to determine regional differences between cohorts segregated by allele status. RESULTS: VBA on the denoised tensor data identified regions of reduced FA in APOE ε4 compared with the APOE ε2 healthy older carriers. The most consistent results were obtained using the denoised tensor and anisotropic smoothing before statistical testing. In contrast, isotropic smoothing identified regional differences for small filter sizes alone, emphasizing that this method introduces bias in FA values for higher kernel sizes. CONCLUSION: Voxel-based DTI analysis can be performed on low signal to noise ratio images to detect subtle regional differences in cohorts using the proposed preprocessing techniques.
Assuntos
Apolipoproteínas E/metabolismo , Encéfalo/metabolismo , Encéfalo/ultraestrutura , Imagem de Tensor de Difusão/métodos , Aumento da Imagem/métodos , Fibras Nervosas Mielinizadas/metabolismo , Fibras Nervosas Mielinizadas/ultraestrutura , Idoso , Algoritmos , Anisotropia , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Masculino , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
PURPOSE: We sought to examine prognostic and therapeutic implications, including cost-effectiveness, of elective neck dissection in the management of patients with clinically-determined T1N0 oral tongue carcinoma. MATERIALS AND METHODS: A retrospective review of patients with cT1N0 oral tongue squamous cell carcinoma who underwent surgical extirpation of primary tumor, with or without elective neck dissection, at UCLA Medical Center from 1990 to 2009 was performed. Cox proportional hazards regression was used to assess effects of variables on time to first loco-regional recurrence. A healthcare costs analysis of elective neck dissection was performed by querying the SEER-Medicare linked database. RESULTS: Of the 123 patients identified with cT1N0 squamous cell carcinoma of the oral tongue, 88 underwent elective neck dissection at the time of tumor resection while 35 did not. For all patients, disease-free survival at 3, 5, and 10 years was 93%, 82%, and 79%. Of the 88 patients undergoing elective neck dissection, 20 (23%) demonstrated occult metastatic disease. Male gender, tumor size, perineural invasion, and occult metastatic disease were individually associated with higher rates of loco-regional recurrence. There was no significant difference in loco-regional recurrence between those who underwent elective neck dissection and those who did not (HR=0.76, p=0.52). On cost analysis, neck dissection was not associated with any significant difference in Medicare payments. CONCLUSIONS: The high rate of occult metastasis (23%) following elective neck dissection, which did not confer additional healthcare costs, leads to the recommendation of elective neck dissection in patients with cT1N0 oral tongue squamous cell carcinoma.
Assuntos
Carcinoma de Células Escamosas/cirurgia , Neoplasias de Cabeça e Pescoço/cirurgia , Esvaziamento Cervical , Neoplasias da Língua/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/economia , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Efeitos Psicossociais da Doença , Feminino , Neoplasias de Cabeça e Pescoço/economia , Neoplasias de Cabeça e Pescoço/mortalidade , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Masculino , Medicare , Pessoa de Meia-Idade , Invasividade Neoplásica , Prognóstico , Estudos Retrospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço , Neoplasias da Língua/economia , Neoplasias da Língua/mortalidade , Neoplasias da Língua/patologia , Estados UnidosRESUMO
Nucleotide binding and oligomeric domain-like receptor X1 (NLRX1), a member of the NLR family, is associated with the physiological and pathological processes of inflammation, autophagy, immunity, metabolism and mitochondrial regulation, and has been demonstrated to have pro- or antitumor effects in various tumor types. However, the biological function of NLRX1 in esophageal squamous cell carcinoma (ESCC) has remained elusive. In the present study, by using bioinformatics methods, the differential expression of NLRX1 at the mRNA level was examined. Overall survival, clinical correlation, receiver operating characteristic curve, Cox regression, co-expression, enrichment, immune infiltration and drug sensitivity analyses were carried out. A nomogram and a calibration curve were constructed. Changes in protein expression levels were investigated by immunohistochemistry and western blotting. The impact of NLRX1 on i) cell proliferation was evaluated by Cell Counting Kit-8 assays; ii) migration was examined by wound-healing assays; iii) migration and invasion were evaluated by Transwell assays; and iv) apoptosis was assessed by Annexin V/PI staining and flow cytometry. The results revealed that, compared to normal adjacent tissue, NLRX1 was lowly expressed in ESCC, and patients with low NLRX1 expression had a shorter survival time. NLRX1 was an independent prognostic factor for ESCC and was associated with tumor grading. Patients in the low-NLRX1 group showed a decrease in the infiltration of activated natural killer cells, monocytes and M0 macrophages, and these immune-cell infiltration levels were positively correlated with NLRX1 expression. Knocking down NLRX1 promoted the proliferation of KYSE450 cells, while overexpression of NLRX1 inhibited the proliferation of ECA109 cells. NLRX1 negatively regulated the PI3K/AKT signaling pathway in ESCC. These findings indicate that, through several mechanisms, NLRX1 suppresses tumor growth in ESCC, which offers new insight for investigating the causes and progression of ESCC, as well as for identifying more efficient therapeutic approaches.
RESUMO
BACKGROUND: Circular RNAs (circRNAs) play critical roles in the tumorigenesis and radiosensitivity of multiple cancers. Nevertheless, the biological functions of circRNA periostin (circ-POSTN) in esophageal cancer (EC) progression and radiosensitivity have not been well elucidated. METHODS: The expression of circ-POSTN, microRNA-876-5p (miR-876-5p), and proto-oncogene tyrosine-protein kinase (FYN) was analyzed by quantitative reverse transcription PCR (RT-qPCR). Cell proliferation was assessed by MTT, colony formation, and 5-ethynyl-2'-deoxyuridine (EDU) assays. All protein levels were detected by western blot assay. Cell apoptosis and invasion were assessed by flow cytometry analysis and transwell assay, respectively. Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were used to validate the interaction between miR-876-5p and circ-POSTN or FYN. The role of circ-POSTN in vivo was explored by establishing mice xenograft model. RESULTS: Circ-POSTN was overexpressed in EC tissues and cells. Knockdown of circ-POSTN inhibited cell proliferation and invasion and elevated apoptosis and radiosensitivity in EC cells. MiR-876-5p was a direct target of circ-POSTN, and its knockdown reversed the role of sh-circ-POSTN in EC cells. FYN was a direct target of miR-876-5p, and FYN elevation weakened the effects of miR-876-5p overexpression on the progression and radiosensitivity of EC cells. Moreover, circ-POSTN acted as a miR-876-5p sponge to regulate FYN expression. Circ-POSTN interference also suppressed tumor growth and enhanced radiosensitivity in vivo. CONCLUSION: Circ-POSTN knockdown inhibited proliferation and invasion, but increased apoptosis and enhanced radiosensitivity in EC cells via modulating miR-876-5p/FYN axis, which might be a potential diagnostic and therapeutic target for EC.
Assuntos
Proliferação de Células , Neoplasias Esofágicas , MicroRNAs , RNA Circular , Tolerância a Radiação , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , RNA Circular/genética , RNA Circular/metabolismo , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/radioterapia , Neoplasias Esofágicas/patologia , Neoplasias Esofágicas/metabolismo , Animais , Camundongos , Tolerância a Radiação/genética , Apoptose , Progressão da Doença , Proto-Oncogene Mas , Masculino , Feminino , Regulação Neoplásica da Expressão Gênica , Moléculas de Adesão Celular/metabolismo , Moléculas de Adesão Celular/genética , Camundongos Nus , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Background: Targeted therapies and immunotherapy are currently considered the mainstay first-line treatment for advanced BRAF-mutated melanoma. However, the impact of treatment (targeted therapy and immunotherapy) and the prognostic factors are still not clear. Material and methods: Medical records of 140 patients diagnosed with advanced melanoma between 2011 and 2021 were retrospectively reviewed to extract demographic, BRAF status, treatment, performance status, and survival data. ORR, PFS, and OS were compared between patients diagnosed with advanced melanoma and treated with first-line IT or BRAF/MEKi. The prognostic factors were assessed using Cox regression models. Results: In all patients and those treated with immunotherapy, we did not find any effect of BRAF status on ORR, PFS, or OS. In patients with BRAF-mutated melanoma, ORR was 43.8% vs. 70% (P=0.04), PFS was 19.2 vs. 11.5 months (p=0.22), and OS was 33.4 vs. 16.4 months for the immunotherapy and targeted therapy groups, respectively (P=0.04). ECOG, presence of brain metastases, and high LDH level from initiation of first-line treatment were all associated with differences in PFS and OS. Conclusion: Patients with advanced BRAF-mutated melanoma treated with first-line immunotherapy had a significantly longer PFS and OS than those treated with first-line BRAF/MEKi; however, first-line BRAF/MEKi treatment had a significantly higher ORR than first-line immunotherapy.
RESUMO
PARP was an enzyme found in the nucleus of eukaryotic cells that played a crucial role in repairing damaged DNA. Recently, PARP inhibitors have demonstrated great potential in cancer treatment. Thus, the FDA has approved several small-molecule PARP inhibitors for cancer maintenance therapy. The combination of PARP inhibitors and radiotherapy relies on synthetic lethality, taking advantage of the flaws in DNA repair pathways to target cancer cells specifically. Studies conducted prior to clinical trials have suggested that the combination of PARP inhibitors and radiotherapy can enhance the sensitivity of cancer cells to radiation, intensify DNA damage, and trigger cell death. Combining radiotherapy with PARP inhibitors in clinical trials has enhanced the response rate and progression-free survival of diverse cancer patients. The theoretical foundation of PARP inhibitors combined with radiotherapy is explained in detail in this article, and the latest advances in preclinical and clinical research on these inhibitors for tumor radiotherapy are summarized. The problems in the current field are recognized in our research and potential therapeutic applications for tumors are suggested. Nevertheless, certain obstacles need to be tackled when implementing PARP inhibitors and radiotherapies in clinical settings. Factors to consider when using the combination therapy are the most suitable schedule and amount of medication, identifying advantageous candidates, and the probable adverse effects linked with the combination. The combination of radiotherapy and PARP inhibitors can greatly enhance the effectiveness of cancer treatment.
RESUMO
Cholecystectomy is one of the most commonly performed surgical interventions, and laparoscopic cholecystectomy is the standard intervention with open cholecystectomies having declined nowadays. Similar to other surgical procedures, cholecystectomy carries its own risks including sepsis, bleeding, damage to surrounding tissues, bile leakage, and abscess formation. Abscess formation can be due to a variety of reasons such as infection or gallstone spillage during surgery with the latter being more common to laparoscopic surgery. Here we describe a patient with an unusual presentation of gallbladder fossa abscess following open cholecystectomy.
RESUMO
Objective: To determine if integrative medicine (IM) involvement can reduce acute care utilization for patients with complex medical conditions and high health care utilization. Design: Prospective single-center cohort study. Interventions: Twenty-nine complex high utilizer patients were treated by the University of California, Los Angeles (UCLA) East-West Extensivist IM specialty clinic with acupuncture, trigger point injections, and Traditional Chinese Medicine dietary modifications. Number of hospitalizations, hospitalization days, and emergency room visits were tracked for 6 months. Results: There was a statistically significant decrease in number of hospitalizations (-31.4%, p = 0.021) and hospitalization days (-38.0%, p = 0.038) after 6 months. Subgroup analysis suggested greater improvement with more frequent visits. Conclusion: IM specialty care correlates with reduced hospitalization frequency and total hospitalization days among high utilizers of care.
Assuntos
Medicina Integrativa , Pacientes Ambulatoriais , Estudos de Coortes , Serviço Hospitalar de Emergência , Hospitalização , Humanos , Aceitação pelo Paciente de Cuidados de Saúde , Estudos ProspectivosRESUMO
In immunoglobulin light-chain (LC) amyloidosis, transient unfolding or unfolding and proteolysis enable aggregation of LC proteins, causing potentially fatal organ damage. A drug that kinetically stabilizes LCs could suppress aggregation; however, LC sequences are variable and have no natural ligands, hindering drug development efforts. We previously identified high-throughput screening hits that bind to a site at the interface between the two variable domains of the LC homodimer. We hypothesized that extending the stabilizers beyond this initially characterized binding site would improve affinity. Here, using protease sensitivity assays, we identified stabilizers that can be divided into four substructures. Some stabilizers exhibit nanomolar EC50 values, a 3000-fold enhancement over the screening hits. Crystal structures reveal a key π-π stacking interaction with a conserved tyrosine residue that was not utilized by the screening hits. These data provide a foundation for developing LC stabilizers with improved binding selectivity and enhanced physicochemical properties.
Assuntos
Amiloide/química , Cumarínicos/química , Desenho de Fármacos , Cadeias Leves de Imunoglobulina/química , Cristalografia por Raios X , Ensaios de Triagem em Larga Escala , Cinética , Modelos Moleculares , Domínios Proteicos , Estabilidade Proteica/efeitos dos fármacosRESUMO
The neuropeptides vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase-activating peptide (PACAP) and their class II G protein-coupled receptors VPAC(1), VPAC(2), and PAC(1) play important roles in human physiology. No small molecule modulator has ever been reported for the VIP/PACAP receptors, and there is a lack of specific VPAC(2) antagonists. Via high-throughput screening of 1.67 million compounds, we discovered a single small molecule antagonist of human VPAC(2), compound 1. Compound 1 inhibits VPAC(2)-mediated cAMP accumulation with an IC(50) of 3.8 microM and the ligand-activated beta-arrestin2 binding with an IC(50) of 2.3 microM. Compound 1 acts noncompetitively in Schild analysis. It is a specific VPAC(2) antagonist with no detectable agonist or antagonist activities on VPAC(1) or PAC(1). Compound 2, a close structural analog of compound 1, was also found to be weakly active. To our surprise, compound 1 is completely inactive on the closely related mouse VPAC(2). Chimera experiments indicate that compounds 1 and 2 bind to the seven transmembrane (7TM) region of the receptor as opposed to the N-terminal extracellular domain, where the natural ligand binds. Compound 1, being the first small molecular antagonist that is specific for VPAC(2), and the only VPAC(2) antagonist molecule known to date that allosterically interacts with the 7TM region, will be a valuable tool in further study of VPAC(2) and related receptors. This study also highlights the opportunities and challenges facing small molecule drug discovery for class II peptide G protein-coupled receptors.
Assuntos
Avaliação Pré-Clínica de Medicamentos , Receptores Tipo II de Peptídeo Intestinal Vasoativo/antagonistas & inibidores , Animais , Sítios de Ligação , AMP Cíclico/metabolismo , Humanos , Concentração Inibidora 50 , Camundongos , Receptores de Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/efeitos dos fármacos , Receptores Tipo I de Polipeptídeo Intestinal Vasoativo/efeitos dos fármacosRESUMO
PURPOSE: To estimate the position and volume errors in 4D-CT caused by irregular breathing. METHODS: A virtual 4D-CT scanner was designed to reproduce axial mode scans with retrospective resorting. This virtual scanner creates an artificial spherical tumor based on the specifications of the user, and recreates images that might be produced by a 4D-CT scanner using a patient breathing waveform. 155 respiratory waveforms of patients were used to test the variability of 4D-CT scans. Each breathing waveform was normalized and scaled to 1, 2, and 3 cm peak-to-peak motion, and artificial tumors with 2 and 4 cm radius were simulated for each scaled waveform. The center of mass and volume of resorted 4D-CT images were calculated and compared to the expected values of center of mass and volume for the artificial tumor. Intrasubject variability was investigated by running the virtual scanner over different subintervals of each patient's breathing waveform. RESULTS: The average error in the center of mass location of an artificial tumor was less than 2 mm standard deviation for 2 cm motion. The corresponding average error in volume was less than 4%. In the worst-case scenarios, a center of mass error of 1.0 cm standard deviation and volume errors of 30%-60% at inhale were found. Systematic errors were observed in a subset of patients due to irregular breathing, and these errors were more pronounced when the tumor volume is smaller. CONCLUSIONS: Irregular breathing during 4D-CT simulation causes systematic errors in volume and center of mass measurements. These errors are small but depend on the tumor size, motion amplitude, and degree of breathing irregularity.
Assuntos
Artefatos , Imageamento Tridimensional/métodos , Neoplasias Pulmonares/diagnóstico por imagem , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Mecânica Respiratória , Técnicas de Imagem de Sincronização Respiratória/métodos , Tomografia Computadorizada por Raios X/métodos , Algoritmos , Humanos , Intensificação de Imagem Radiográfica/métodos , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Audience: This simulation is designed to educate emergency medicine residents and medical students on the recognition and management of cardiac tamponade, as well as encourage providers to become familiar with their states' disclosure laws for sentinel events. Introduction: Cardiac tamponade is an emergent condition in which the accumulation of pericardial fluid and the consequent increase in hydrostatic pressure becomes severe enough to compromise the normal diastolic and systolic function of the heart, resulting in hemodynamic instability.1 The causes of cardiac tamponade are numerous because it is a potential complication of any of a number of pericardial disease processes, including infectious, inflammatory, traumatic, and malignant etiologies.1,2 Clinical presentations may vary and symptoms can be non-specific, which can lead to delayed or missed diagnoses and poor patient outcomes.3 In addition to this, the incidence of this condition is rising due to the increasing frequency of cardiac procedures performed (ie, pacemaker placement).4 Therefore, it is important for medical providers to have a high index of suspicion for the diagnosis based on patient presentation and to quickly provide necessary treatment to stabilize the patient. Educational Objectives: By the end of this simulation session, the learner will be able to: (1) describe a diagnostic differential for dizziness (2) describe the pathophysiology of cardiac tamponade (3) describe the acute management of cardiac tamponade, including fluid bolus and pericardiocentesis (4) describe the electrocardiogram (ECG) findings of pericardial effusion (5) describe the ultrasound findings of cardiac tamponade (6) describe the indications for emergent bedside pericardiocentesis versus medical stabilization and delayed pericardiocentesis for cardiac tamponade (7) describe the procedural steps for pericardiocentesis, and (8) describe your state's laws regarding disclosure for sentinel events. Educational Methods: This session is conducted using high-fidelity simulation, followed by a debriefing session on evaluation and treatment of cardiac tamponade. However, it may also be run as an oral board case. Educational Methods: Our residents were provided an electronic survey at the completion of the debriefing session so they may rate different aspects of the simulation, as well as provide qualitative feedback on the scenario. This survey is specific to the local institution's simulation center. Results: Feedback was largely positive because many learners mentioned during debriefing that they are not comfortable with pericardiocentesis and have limited opportunities to practice the procedure. None of our residents were familiar with our state's or institution's disclosure laws for sentinel events.The local institution's simulation center feedback form is based on the Center of Medical Simulation's Debriefing Assessment for Simulation in Healthcare (DASH) Student Version Short Form with the inclusion of required qualitative feedback if an element was scored less than a 6 or 7.5 This session received a majority of 6 (consistently effective/very good) and 7 scores (extremely effective/outstanding). Discussion: This is a potential method for educating future medical providers on the diagnosis and management of cardiac tamponade in an emergency department setting. Learners initially had a wide range of differentials for the chief complaint of dizziness. We used an ECG with low voltage but without electrical alternans. When asked to provide an ECG interpretation, low voltage was intermittently explicitly interpreted by learners. We were concerned that if we showed an ECG with electrical alternans, learners may quickly arrive at the diagnosis without focusing on the subtleties of a physical exam, including looking for jugular venous distention (JVD) or pulsus paradoxus.We did not have the patient decompensate if their international normalized ratio (INR) was not immediately reversed, given likely delay for in vivo coagulation to occur in the face of life-threatening tamponade, but this provided a robust discussion during debriefing if reversal should be emergently initiated.Many residents voiced that they were uncomfortable performing a pericardiocentesis because they only had a few opportunities to do so on human cadavers, and they appreciated the opportunity to review this.Unexpectedly, when the patient asked the learners if he should sue the cardiologist, the majority of groups told the patient that the cardiologist was not liable because tamponade is a known complication of cardiac ablation and likely reviewed this while obtaining informed consent. None of the learners were familiar with Ohio's disclosure laws for sentinel events. This identified a gap in knowledge that may be addressed in future learning sessions.Our main take-away is to continue providing low-frequency, high-acuity cases that provide the opportunity to review infrequent pathologies and procedures, as well as including patient safety and administrative learning points. Topics: Medical simulation, cardiac tamponade, pericardial effusion, cardiac emergencies, obstructive shock, sentinel events, iatrogenic injury, medical disclosure.
RESUMO
Aims: To investigate the immune and gastrointestinal functional effects of lienal polypeptide (LP) treatment in tumor-bearing mice and carcinoma patients receiving radiotherapy (RT), and to detect hematological indicators and T lymphocyte subsets. Methods: Tumor-bearing mice were randomly divided into five groups: the control group, the RT group, the RT+LP-L (1.7 mg/kg, low dosage of LP) group, the RT+LP-M (5.2 mg/kg, middle dosage of LP) group, and the RT+LP-H (10.4 mg/kg, high dosage of LP) group. In addition, carcinoma patients were randomly divided into two groups. The observation group was given LP during RT, and the control group was only treated with RT. We then compared the myelosuppression, gastrointestinal reactions, and clinical efficacy among groups. Results: In the animal experiments, compared with the control group, the number of leukocytes and lymphocytes of the mice in the "RT" group decreased (p < 0.05). Animals receiving LP evidenced a dose-response curve with regard to the number of leukocytes and lymphocytes that was proportional to the LP dose, increased (p < 0.05). Flow cytometric analyses showed that LP treatment of the mice increased the numbers of CD3+, and CD4+ T cells and theCD4+/CD8+ ratio. In our clinical study, the Radiation Therapy Oncology Group (RTOG)/European Organization for Research and Treatment of Cancer (EORTC) criteria were used for measuring myelosuppression and gastrointestinal reactions. The RTOG/EORTC grade 3 or 4 inhibition rate of leukocytes, granulocytes, hemoglobin, platelets, and gastrointestinal toxic effects in the observation group were significantly lower than that in the control group (p < 0.05). Conclusion: LP can improve the hematopoietic and immune function of RT-treated mice and reduce the hematological and gastrointestinal toxicity of patients treated with RT and improve the quality of life.
Assuntos
Peptídeos , Lesões Experimentais por Radiação/tratamento farmacológico , Radioterapia/efeitos adversos , Animais , Linhagem Celular Tumoral , Feminino , Masculino , Camundongos , Camundongos Endogâmicos ICR , Peptídeos/efeitos adversos , Peptídeos/farmacologia , Lesões Experimentais por Radiação/metabolismo , Lesões Experimentais por Radiação/patologiaRESUMO
Stimulator of interferon genes (STING) links innate immunity to biological processes ranging from antitumor immunity to microbiome homeostasis. Mechanistic understanding of the anticancer potential for STING receptor activation is currently limited by metabolic instability of the natural cyclic dinucleotide (CDN) ligands. From a pathway-targeted cell-based screen, we identified a non-nucleotide, small-molecule STING agonist, termed SR-717, that demonstrates broad interspecies and interallelic specificity. A 1.8-angstrom cocrystal structure revealed that SR-717 functions as a direct cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) mimetic that induces the same "closed" conformation of STING. SR-717 displayed antitumor activity; promoted the activation of CD8+ T, natural killer, and dendritic cells in relevant tissues; and facilitated antigen cross-priming. SR-717 also induced the expression of clinically relevant targets, including programmed cell death 1 ligand 1 (PD-L1), in a STING-dependent manner.