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PURPOSE: The COVID-19 pandemic has affected healthcare systems worldwide. Data on the impact on otolaryngological clinics and private practices is sparse. This study aimed to present data on healthcare worker (HCW) screening, status of HCW, pre-interventional testing, the use of personal protective equipment (PPE) and the economic impact of the pandemic. METHODS: Otolaryngological private practices and hospital-based departments were surveyed nationwide using an online questionnaire. Participating facilities were recruited via the German Society for Oto-Rhino-Laryngology and the German Association for Otolaryngologists in Bavaria. RESULTS: 365 private practices (2776 employees) and 65 hospitals (2333 employees) were included. Significantly more hospitals (68.7%) than practices (40.5%) performed pre-interventional testing in their outpatients (p < 0.00). Most inpatients were tested in practices and hospitals (100.0% and 95.0%; p = 0.08). HCW screening was performed in 73.7% of practices and in 77.3% of hospitals (p = 0.54). Significantly more HCW infections were reported in private practices (4.7%) than in hospital (3.6%; p = 0.03). The private or home environment was the most frequent source of infection among HCW in hospitals (44%) and practices (63%). The use of PPE increased over the course of the pandemic. The number of procedures and the revenue decreased in 2020. CONCLUSION: The rate of pre-interventional testing among outpatients in otolaryngological practices is low and HCW infections were found to be more frequent in practices than in hospitals. In addition, a high rate of infections in otolaryngological HCW seems to stem from the private or home environment.
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COVID-19 , Otolaringología , Pandemias , Práctica Privada , Alemania/epidemiología , Personal de Salud , Ambiente en el Hogar , Hospitales , Humanos , Equipo de Protección PersonalRESUMEN
BACKGROUND: An audit of the Fellowship of the College of Surgeons (FCS) of South Africa examination results has not been previously performed. The purpose of this study was to review and determine any predictors of outcome (pass or fail). METHODS: The results of the FCS(SA) final examinations from October 2005 to and including October 2014, were retrieved from the College of Medicine of South Africa database. The current format of the examinations consists of two written essay question papers, an objectively structured clinical examination (OSCE), two clinical cases and two oral examinations. These were retrospectively reviewed and analysed. Predictors of failure or success were determined. RESULTS: During the 10-year study period, 472 candidates attempted the examinations. A total of 388 (82%) candidates were successful in the written component of the examination and were subsequently invited to participate in the clinical component of the examinations. Overall, 296 (63%) candidates passed and 176 (37%) failed. There were 51 candidates who were invited to the oral examinations despite an average of less than 50% in the two papers, and 34 (67%) failed the overall examination. Similarly, 126 candidates were invited having failed one of the two papers of which 81 (64%) ultimately failed. A total of 49 candidates failed the OSCE, 82% of these candidates failed overall. There were strong correlations between the averages of the papers versus the orals (Spearman ρ = 0.51), the papers versus the cases (Spearman ρ = 0.50), and the papers versus the OSCE (Spearman ρ = 0.55). CONCLUSION: The written papers are the main determinant of invitation to the second part of the examination. Candidates with marginal scores in the written component had an overall failure rate of 67%. Failing one paper and passing the other, resulted in an overall failure rate of 64%. Failing the OSCE resulted in an overall 82% failure rate. With the high failure rate of candidates with marginal scores and with the inter-examination variability of the papers, it might be prudent to revisit both the process of invitation selection and the decision to continue with the long-form of the written component.
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Competencia Clínica , Educación de Postgrado en Medicina/métodos , Cirugía General/educación , Licencia Médica , Cirujanos/educación , Evaluación Educacional , Femenino , Humanos , Masculino , Auditoría Médica , Estudios Retrospectivos , Sociedades Médicas , Sudáfrica , Factores de TiempoRESUMEN
Obesity confers an independent risk for carcinogenesis. In the liver, steatosis often proceeds cancer formation; however, the mechanisms by which steatosis promotes carcinogenesis is unknown. We hypothesize that steatosis alters the microenvironment to promote proliferation of tumor initiating cells (TICs) and carcinogenesis. We used several liver cancer models to address the mechanisms underlying the role of obesity in cancer and verified these findings in patient populations. Using bioinformatics analysis and verified by biochemical assays, we identified that hepatosteatosis resulting from either Pten deletion or transgenic expression of HCV core/NS5A proteins, promotes the activation of Wnt/ß-catenin. We verified that high fat diet lipid accumulation is also capable of inducing Wnt/ß-catenin. Caloric restriction inhibits hepatosteatosis, reduces Wnt/ß-catenin activation and blocks the expansion of TICs leading to complete inhibition of tumorigenesis without affecting the phosphatase and tensin homologue deleted on chromosome 10 (PTEN) loss regulated protein kinase B (AKT) activation. Pharmacological inhibition or loss of the Wnt/ß-catenin signal represses TIC growth in vitro, and decreases the accumulation of TICs in vivo. In human liver cancers, ontology analysis of gene set enrichment analysis (GSEA)-defined Wnt signature genes indicates that Wnt signaling is significantly induced in tumor samples compared with healthy livers. Indeed, Wnt signature genes predict 90% of tumors in a cohort of 558 patient samples. Selective depletion of macrophages leads to reduction of Wnt and suppresses tumor development, suggesting infiltrating macrophages as a key source for steatosis-induced Wnt expression. These data established Wnt/ß-catenin as a novel signal produced by infiltrating macrophages induced by steatosis that promotes growth of tumor progenitor cells, underlying the increased risk of liver tumor development in obese individuals.
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Carcinogénesis/genética , Hígado Graso/genética , Neoplasias Hepáticas/genética , Obesidad/genética , Animales , Línea Celular Tumoral , Hígado Graso/complicaciones , Hígado Graso/patología , Humanos , Hígado/metabolismo , Hígado/patología , Neoplasias Hepáticas/etiología , Neoplasias Hepáticas/patología , Macrófagos/metabolismo , Macrófagos/patología , Células Madre Neoplásicas/metabolismo , Obesidad/complicaciones , Obesidad/patología , Fosfohidrolasa PTEN/genética , Fosforilación/genética , Proteínas Proto-Oncogénicas c-akt , Vía de Señalización Wnt/genética , beta Catenina/genéticaRESUMEN
Our group recently introduced a new process to synthesize nanoparticle shells of about 100 nm, named "hybridosomes®". Here, the structure and mechanical properties of hybridosomes® made from iron oxide nanoparticles and poly(acrylic acid) are characterized using TEM, AFM and an osmotic compression technique. For the latter, the size distribution of the hybridosomes is monitored by nanoparticle tracking analysis (NTA) in the presence of poly(ethylene glycol)s of different molecular weights. It is found that the size of the hybridosomes® can be tuned from ca. 80 nm to over 110 nm by adjusting the amount of nanoparticles and that their shell consists of a single layer of nanoparticles, with a porous structure. The size of the pores is estimated from osmotic compression experiments at ca. 4000 g mol-1. The mechanical properties are measured both at the ensemble level using size measurements under osmotic pressure and at the single nanoparticle level by atomic force microscopy nanoindentation. Both osmotic and AFM experiments are analyzed in the framework of the continuum elastic theory of thin shells and yield a value of Young's modulus of the order of MPa.
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Eighteen Quarter Horses were used in a randomized complete design for a 28-d experiment to evaluate age-related effects on inflammation and cartilage turnover after induction of a single inflammatory insult using lipopolysaccharide (LPS). Horses were grouped by age as yearlings (3 males and 3 females), 2 to 3 yr olds (2/3 yr old; 2 males and 4 females), and skeletally mature 5 to 8 yr olds (mature; 2 males and 4 females). On d 0, all horses were individually housed and fed diets that met or exceeded requirements. On d 14, horses were challenged with an intra-articular injection of LPS. Radial carpal joints were randomly assigned to receive 0.5 ng LPS solution obtained from O55:B5 or 0.8 mL sterile lactated Ringer's solution as a contralateral control. Synovial fluid was collected prior to LPS injection at h 0 before injection and at 6, 12, 24, 168, and 336 h after injection. Samples were analyzed using commercial ELISA kits for PGE, collagenase cleavage neoepitope (C2C), and carboxypropeptide of type II collagen (CPII). Heart rate (HR), respiratory rate (RR), and rectal temperature (RT) were monitored over the initial 24 h and carpal circumference and surface temperature were also recorded, with additional measurements at 168 and 336 h. Data were analyzed using PROC MIXED of SAS. Values for RT, HR, and RR were within the normal range for each age group. Heart rate and RT were influenced by age ( < 0.01), whereas RR was unaffected ( ≤ 0.21). Joint circumference was not influenced by age of horse ( = 0.84), but circumference and surface temperature increased ( < 0.01) over time across all age groups. Synovial PGE concentrations tended ( = 0.09) to be influenced by age, with yearlings having lower ( = 0.03) concentrations than mature horses. Concentrations of synovial C2C were affected by age of horse, with yearlings and 2/3 yr olds having lower ( < 0.01) concentrations than mature horses. Similarly, synovial CPII was influenced by age, with yearlings and 2/3 yr olds having lower ( ≤ 0.02) concentrations than mature horses. Ratios of anabolic CPII to catabolic C2C varied by age, with mature and 2/3-yr-old horses having greater ( < 0.01) values compared with yearlings. These results indicate that inflammation and the corresponding cartilage turnover in response to LPS administration vary with age.
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Cartílago Articular/metabolismo , Cartílago/metabolismo , Enfermedades de los Caballos/metabolismo , Inflamación/veterinaria , Lipopolisacáridos/toxicidad , Líquido Sinovial/química , Envejecimiento , Animales , Biomarcadores/metabolismo , Ensayo de Inmunoadsorción Enzimática/veterinaria , Femenino , Caballos , Inflamación/sangre , Inflamación/metabolismo , Inyecciones Intraarticulares/veterinaria , MasculinoRESUMEN
OBJECTIVES: To reflect on the notable events and significant developments in Clinical Research Informatics (CRI) in the year of 2015 and discuss near-term trends impacting CRI. METHODS: We selected key publications that highlight not only important recent advances in CRI but also notable events likely to have significant impact on CRI activities over the next few years or longer, and consulted the discussions in relevant scientific communities and an online living textbook for modern clinical trials. We also related the new concepts with old problems to improve the continuity of CRI research. RESULTS: The highlights in CRI in 2015 include the growing adoption of electronic health records (EHR), the rapid development of regional, national, and global clinical data research networks for using EHR data to integrate scalable clinical research with clinical care and generate robust medical evidence. Data quality, integration, and fusion, data access by researchers, study transparency, results reproducibility, and infrastructure sustainability are persistent challenges. CONCLUSION: The advances in Big Data Analytics and Internet technologies together with the engagement of citizens in sciences are shaping the global clinical research enterprise, which is getting more open and increasingly stakeholder-centered, where stakeholders include patients, clinicians, researchers, and sponsors.
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Investigación Biomédica , Informática Médica , Medicina de Precisión , Investigación Biomédica/tendencias , Minería de Datos , Conjuntos de Datos como Asunto , Registros Electrónicos de Salud , Humanos , Internet , Informática Médica/tendenciasRESUMEN
BACKGROUND AND PURPOSE: Mild traumatic brain injury results in a heterogeneous constellation of deficits and symptoms that persist in a subset of patients. This prospective longitudinal study identifies early diffusion tensor imaging biomarkers of mild traumatic brain injury that significantly relate to outcomes at 1 year following injury. MATERIALS AND METHODS: DTI was performed on 39 subjects with mild traumatic brain injury within 16 days of injury and 40 controls; 26 subjects with mild traumatic brain injury returned for follow-up at 1 year. We identified subject-specific regions of abnormally high and low fractional anisotropy and calculated mean fractional anisotropy, axial diffusivity, radial diffusivity, and mean diffusivity across all white matter voxels brain-wide and each of several white matter regions. Assessment of cognitive performance and symptom burden was performed at 1 year. RESULTS: Significant associations of brain-wide DTI measures and outcomes included the following: mean radial diffusivity and mean diffusivity with memory; and mean fractional anisotropy, radial diffusivity, and mean diffusivity with health-related quality of life. Significant differences in outcomes were found between subjects with and without abnormally high fractional anisotropy for the following white matter regions and outcome measures: left frontal lobe and left temporal lobe with attention at 1 year, left and right cerebelli with somatic postconcussion symptoms at 1 year, and right thalamus with emotional postconcussion symptoms at 1 year. CONCLUSIONS: Individualized assessment of DTI abnormalities significantly relates to long-term outcomes in mild traumatic brain injury. Abnormally high fractional anisotropy is significantly associated with better outcomes and might represent an imaging correlate of postinjury compensatory processes.
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CREB-binding protein (CBP) and p300 are highly homologous transcriptional coactivators with unique, non-redundant roles that bind a wide array of proteins, including catenins-ß and γ. ICG-001 is a small-molecule inhibitor that specifically inhibits the CBP/catenin interaction. Importantly, ICG-001 does not inhibit the p300/catenin interaction. We demonstrate that specifically inhibiting the interaction between CBP and catenin with ICG-001 results in the differentiation of quiescent drug-resistant chronic myelogenous leukemia-initiating cells (CML LICs), thereby sensitizing them to BCR-ABL tyrosine kinase inhibitors, for example, Imatinib. Using ICG-001 in a NOD/SCID/IL2Rγ(-/-) mouse model of engrafted human chronic myelogenous leukemia, we now demonstrate the complete elimination of engrafted leukemia after only one course of combined chemotherapy. Combination-treated animals live as long as their non-engrafted littermates. Results from these studies demonstrate that specifically antagonizing the CBP/catenin interaction with ICG-001 can eliminate drug-resistant CML LICs without deleterious effects to the normal endogenous hematopoietic stem cell population.
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Proteína de Unión a CREB/metabolismo , Cateninas/metabolismo , Leucemia Mielógena Crónica BCR-ABL Positiva/metabolismo , Células Madre Neoplásicas/metabolismo , Animales , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Línea Celular Tumoral , Resistencia a Antineoplásicos/efectos de los fármacos , Proteína p300 Asociada a E1A/metabolismo , Femenino , Proteínas de Fusión bcr-abl/antagonistas & inhibidores , Proteínas de Fusión bcr-abl/genética , Proteínas de Fusión bcr-abl/metabolismo , Humanos , Immunoblotting , Subunidad gamma Común de Receptores de Interleucina/deficiencia , Subunidad gamma Común de Receptores de Interleucina/genética , Células K562 , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Leucemia Mielógena Crónica BCR-ABL Positiva/genética , Ratones Endogámicos NOD , Ratones Noqueados , Ratones SCID , Células Madre Neoplásicas/efectos de los fármacos , Unión Proteica/efectos de los fármacos , Pirimidinonas/farmacología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Ensayos Antitumor por Modelo de Xenoinjerto/métodosRESUMEN
A photo-controlled and quasi-reversible switch of the luminescence of hexadecylamine-coated ZnO nanocrystals (ZnO@HDA Ncs) is operated via a molecular photoswitch (dithienylethene, DTE). The interaction between the DTE switch and the ZnO@HDA Ncs is thoroughly investigated using NMR spectroscopy techniques, including DOSY and NOESY, showing that the DTE switch is weakly adsorbed at the surface of the Ncs through the formation of hydrogen bonds with HDA. Steady state and time-resolved luminescence quenching experiments show a complex behavior, related to the spatial distribution of the emitting defects in the Ncs. Analysis of the data using models previously developed for Ncs supports static quenching. Both isomeric forms (open or closed) of the DTE switch quench the emission of Ncs, the efficiency being more than ten times higher for the closed isomer. The mechanism of quenching is discussed and we show that quenching occurs mainly through resonant energy transfer for the closed isomer and through electron transfer for the open one. The HDA layer mediates the quenching efficiency as only defects located near the surface are quenched.
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OBJECTIVE: Acute heart failure syndrome (AHFS) is a major cause of hospitalisation and imparts a substantial burden on patients and healthcare systems. Tools to define risk of AHFS hospitalisation are lacking. METHODS: A prospective cohort study (n=628) of patients with stable chronic heart failure (CHF) secondary to left ventricular systolic dysfunction was used to derive an AHFS prediction model which was then assessed in a prospectively recruited validation cohort (n=462). RESULTS: Within the derivation cohort, 44 (7%) patients were hospitalised as a result of AHFS during 1â year of follow-up. Predictors of AHFS hospitalisation included furosemide equivalent dose, the presence of type 2 diabetes mellitus, AHFS hospitalisation within the previous year and pulmonary congestion on chest radiograph, all assessed at baseline. A multivariable model containing these four variables exhibited good calibration (Hosmer-Lemeshow p=0.38) and discrimination (C-statistic 0.77; 95% CI 0.71 to 0.84). Using a 2.5% risk cut-off for predicted AHFS, the model defined 38.5% of patients as low risk, with negative predictive value of 99.1%; this low risk cohort exhibited <1% excess all-cause mortality per annum when compared with contemporaneous actuarial data. Within the validation cohort, an identically applied model derived comparable performance parameters (C-statistic 0.81 (95% CI 0.74 to 0.87), Hosmer-Lemeshow p=0.15, negative predictive value 100%). CONCLUSIONS: A prospectively derived and validated model using simply obtained clinical data can identify patients with CHF at low risk of hospitalisation due to AHFS in the year following assessment. This may guide the design of future strategies allocating resources to the management of CHF.
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Técnicas de Apoyo para la Decisión , Insuficiencia Cardíaca/etiología , Hospitalización , Disfunción Ventricular Izquierda/complicaciones , Anciano , Distribución de Chi-Cuadrado , Enfermedad Crónica , Diabetes Mellitus Tipo 2/complicaciones , Inglaterra , Femenino , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/mortalidad , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/terapia , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Oportunidad Relativa , Readmisión del Paciente , Valor Predictivo de las Pruebas , Pronóstico , Estudios Prospectivos , Medición de Riesgo , Factores de Riesgo , Inhibidores del Simportador de Cloruro Sódico y Cloruro Potásico/uso terapéutico , Factores de Tiempo , Disfunción Ventricular Izquierda/diagnóstico , Disfunción Ventricular Izquierda/mortalidad , Disfunción Ventricular Izquierda/fisiopatología , Función Ventricular IzquierdaRESUMEN
Wnt/ß-catenin signaling has a central role in the development and progression of most colon cancers (CCs). Germline variants in Wnt/ß-catenin pathway genes may result in altered gene function and/or activity, thereby causing inter-individual differences in relation to tumor recurrence capacity and chemoresistance. We investigated germline polymorphisms in a comprehensive panel of Wnt/ß-catenin pathway genes to predict time to tumor recurrence (TTR) in patients with stage III and high-risk stage II CC. A total of 234 patients treated with 5-fluorouracil-based chemotherapy were included in this study. Whole-blood samples were analyzed for putative functional germline polymorphisms in SFRP3, SFRP4, DKK2, DKK3, Axin2, APC, TCF7L2, WNT5B, CXXC4, NOTCH2 and GLI1 genes by PCR-based restriction fragment-length polymorphism or direct DNA sequencing. Polymorphisms with statistical significance were validated in an independent study cohort. The minor allele of WNT5B rs2010851 T>G was significantly associated with a shorter TTR (10.7 vs 4.9 years; hazard ratio: 2.48; 95% CI, 0.96-6.38; P=0.04) in high-risk stage II CC patients. This result remained significant in multivariate Cox's regression analysis. This study shows that the WNT5B germline variant rs2010851 was significantly identified as a stage-dependent prognostic marker for CC patients after 5-fluorouracil-based adjuvant therapy.
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Neoplasias del Colon/genética , Recurrencia Local de Neoplasia/genética , Proteínas Wnt/genética , Vía de Señalización Wnt/genética , Adulto , Anciano , Anciano de 80 o más Años , Alelos , Neoplasias del Colon/tratamiento farmacológico , Neoplasias del Colon/patología , Etnicidad/genética , Femenino , Fluorouracilo/administración & dosificación , Humanos , Masculino , Persona de Mediana Edad , Recurrencia Local de Neoplasia/patología , Estadificación de Neoplasias , Polimorfismo de Nucleótido Simple , Pronóstico , Modelos de Riesgos ProporcionalesRESUMEN
Drug resistance in acute lymphoblastic leukemia (ALL) remains a major problem warranting new treatment strategies. Wnt/catenin signaling is critical for the self-renewal of normal hematopoietic progenitor cells. Deregulated Wnt signaling is evident in chronic and acute myeloid leukemia; however, little is known about ALL. Differential interaction of catenin with either the Kat3 coactivator CREBBP (CREB-binding protein (CBP)) or the highly homologous EP300 (p300) is critical to determine divergent cellular responses and provides a rationale for the regulation of both proliferation and differentiation by the Wnt signaling pathway. Usage of the coactivator CBP by catenin leads to transcriptional activation of cassettes of genes that are involved in maintenance of progenitor cell self-renewal. However, the use of the coactivator p300 leads to activation of genes involved in the initiation of differentiation. ICG-001 is a novel small-molecule modulator of Wnt/catenin signaling, which specifically binds to the N-terminus of CBP and not p300, within amino acids 1-110, thereby disrupting the interaction between CBP and catenin. Here, we report that selective disruption of the CBP/ß- and γ-catenin interactions using ICG-001 leads to differentiation of pre-B ALL cells and loss of self-renewal capacity. Survivin, an inhibitor-of-apoptosis protein, was also downregulated in primary ALL after treatment with ICG-001. Using chromatin immunoprecipitation assay, we demonstrate occupancy of the survivin promoter by CBP that is decreased by ICG-001 in primary ALL. CBP mutations have been recently identified in a significant percentage of ALL patients, however, almost all of the identified mutations reported occur C-terminal to the binding site for ICG-001. Importantly, ICG-001, regardless of CBP mutational status and chromosomal aberration, leads to eradication of drug-resistant primary leukemia in combination with conventional therapy in vitro and significantly prolongs the survival of NOD/SCID mice engrafted with primary ALL. Therefore, specifically inhibiting CBP/catenin transcription represents a novel approach to overcome relapse in ALL.
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Antineoplásicos/farmacología , Compuestos Bicíclicos Heterocíclicos con Puentes/farmacología , Fragmentos de Péptidos/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Pirimidinonas/farmacología , Sialoglicoproteínas/metabolismo , beta Catenina/metabolismo , Animales , Asparaginasa/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Dexametasona/farmacología , Regulación hacia Abajo/efectos de los fármacos , Resistencia a Antineoplásicos , Sinergismo Farmacológico , Humanos , Proteínas Inhibidoras de la Apoptosis/genética , Proteínas Inhibidoras de la Apoptosis/metabolismo , Ratones , Ratones Endogámicos NOD , Ratones SCID , Mutación , Fragmentos de Péptidos/antagonistas & inhibidores , Fragmentos de Péptidos/genética , Sialoglicoproteínas/antagonistas & inhibidores , Sialoglicoproteínas/genética , Survivin , Vincristina/farmacología , Vía de Señalización Wnt , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
BACKGROUND: Ectodomain shedding of glycoprotein Ibα (GPIbα), a proteolytic event in which metalloprotease ADAM17 cleaves the Gly464-Val465 bond and releases glycocalicin to the plasma, is considered a critical step in mediating clearance of stored platelets. Supporting evidence has largely come from studies using ADAM17 inhibitors. However, the definitive proof is lacking due to the broad substrate specificity of ADAM17. AIM: To achieve substrate-specific inhibition of GPIbα shedding. METHODS: Development of monoclonal antibodies that directly bind the sequence around the GPIbα shedding cleavage site and inhibit GPIbα shedding by blocking ADAM17 access to the cleavage site. RESULTS: Six anti-GPIbα monoclonal antibodies with varying binding affinities were obtained. The prototypic clone, designated 5G6, and its monomeric Fab fragment bind specifically purified GPIb-IX complex, human platelets, and transgenic murine platelets expressing human GPIbα. The clone 5G6 showed similar inhibitory potency as a widely used shedding inhibitor GM6001 in both constitutive and induced GPIbα shedding in human platelets. It does not recognize mouse GPIbα or inhibit shedding of other platelet receptors. Finally, 5G6 binding displays no detectable effect on platelet activation and aggregation. CONCLUSIONS: The clone 5G6 specifically inhibits GPIbα shedding with no detectable effect on platelet functions. The method of substrate-specific shedding inhibition by macromolecular binding of the shedding cleavage site can be applicable to many other transmembrane receptors undergoing ectodomain shedding.
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Complejo GPIb-IX de Glicoproteína Plaquetaria/antagonistas & inhibidores , Animales , Western Blotting , Citometría de Flujo , Humanos , Ratones , Ratones Endogámicos C57BL , Activación Plaquetaria , Agregación Plaquetaria , Complejo GPIb-IX de Glicoproteína Plaquetaria/fisiología , ProteolisisRESUMEN
Recent studies suggest CD133, a surface protein widely used for isolation of colon cancer stem cells, to be associated with tumor angiogenesis and recurrence. We hypothesized that gene expression levels and germline variations in CD133 will predict clinical outcome in patients with metastatic colorectal cancer (mCRC), treated in first-line setting with 5-fluorouracil, oxaliplatin and bevacizumab (BV), and we investigated whether there is a correlation with gene expression levels of CD133, vascular endothelial growth factor (VEGF) and its receptors. We evaluated intra-tumoral gene expression levels by quantitative real-time (RT) PCR from 54 patients and three germline variants of the CD133 gene by PCR-restriction-fragment length polymorphism from 91 patients with genomic DNA. High gene expression levels of CD133 (>7.76) conferred a significantly greater tumor response (RR=86%) than patients with low expression levels (îº7.76, RR=38%, adjusted P=0.003), independent of VEGF or its receptor gene expression levels. Gene expression levels of CD133 were significantly associated with VEGF and its receptors messenger RNA levels (VEGFR-1 (P<0.01), -2 and -3, P<0.05). Combined analyses of two polymorphisms showed a significant association with progression-free survival (PFS) (18.5 months vs 9.8 months, P=0.004) in a multivariate analysis as an independent prognostic factor for PFS (adjusted P=0.002). These results suggest that CD133 is a predictive marker for standard first-line BV-based treatment in mCRC.
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Anticuerpos Monoclonales Humanizados/administración & dosificación , Antígenos CD/genética , Biomarcadores de Tumor/genética , Neoplasias Colorrectales/genética , Glicoproteínas/genética , Péptidos/genética , Antígeno AC133 , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Monoclonales Humanizados/efectos adversos , Bevacizumab , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/patología , Supervivencia sin Enfermedad , Femenino , Fluorouracilo/administración & dosificación , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Glicoproteínas/farmacocinética , Humanos , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Péptidos/farmacocinética , Polimorfismo de Nucleótido Simple , Pronóstico , Receptores de Factores de Crecimiento Endotelial Vascular/genética , Receptores de Factores de Crecimiento Endotelial Vascular/metabolismo , Resultado del Tratamiento , Factor A de Crecimiento Endotelial Vascular/genética , Factor A de Crecimiento Endotelial Vascular/metabolismoRESUMEN
Coronary artery disease (CAD) accounts for approximately one-half of the sizable mortality in patients with end-stage renal disease who have undergone transplantation. The study was a retrospective review of 1460 patients who underwent renal transplantation at the Mount Sinai Medical Center from January 1, 2000 to October 31, 2009. Noninvasive stress testing was performed in 848 patients (88.1%) with 278 patients (32.8%) having abnormal results. Cardiac catheterization was performed in 357 patients (37.1%) and of these, 212 patients had obstructive disease (59.4%). At 5 years posttransplant, there was no statistically significant difference between those with nonobstructive CAD and those who required percutaneous or surgical interventions (adjusted hazard ratio [aHR], 1.243; CI 95%, 0.513-3.010; p = 0.630). Those with medically managed obstructive CAD had significantly higher rates of death at the 5-year period when compared to those who received percutaneous intervention (aHR, 3.792; CI 95%, 1.320-10.895; p = 0.013) or those who received coronary artery bypass grafting (aHR, 6.691; CI 95%, 1.200-37.323). Because noninvasive imaging is poorly predictive of coronary disease in this high-risk population, an anatomic diagnosis is recommended. Revascularization may result in improved long-term outcomes.
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Enfermedad de la Arteria Coronaria/diagnóstico por imagen , Enfermedad de la Arteria Coronaria/etiología , Fallo Renal Crónico/complicaciones , Fallo Renal Crónico/terapia , Trasplante de Riñón/efectos adversos , Radiografía Intervencional , Anciano , Angiografía Coronaria , Enfermedad de la Arteria Coronaria/mortalidad , Prueba de Esfuerzo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Factores de Riesgo , Tasa de SupervivenciaRESUMEN
PURPOSE: recent studies have found that KRAS mutations predict resistance to monoclonal antibodies targeting the epidermal growth factor receptor in metastatic colorectal cancer (mCRC). A polymorphism in a let-7 microRNA complementary site (lcs6) in the KRAS 3' untranslated region (UTR) is associated with an increased cancer risk in non-small-cell lung cancer and reduced overall survival (OS) in oral cancers. We tested the hypothesis whether this polymorphism may be associated with clinical outcome in KRAS wild-type (KRASwt) mCRC patients treated with cetuximab monotherapy. PATIENTS AND METHODS: the presence of KRAS let-7 lcs6 polymorphism was evaluated in 130 mCRC patients who were enrolled in a phase II study of cetuximab monotherapy (IMCL-0144). Genomic DNA was extracted from dissected formalin-fixed paraffin-embedded tumor tissue, KRAS mutation status and polymorphism were assessed using direct sequencing and PCR restriction fragment length polymorphism technique. RESULTS: KRAS let-7 lcs6 polymorphism was found to be related to object response rate (ORR) in mCRC patients whose tumors had KRASwt. The 12 KRASwt patients harboring at least a variant G allele (TG or GG) had a 42% ORR compared with a 9% ORR in 55 KRASwt patients with let-7 lcs6 TT genotype (P = 0.02, Fisher's exact test). KRASwt patients with TG/GG genotypes had trend of longer median progression-free survival (3.9 versus 1.3 months) and OS (10.7 versus 6.4 months) compared to those with TT genotypes. CONCLUSIONS: these results are the first to indicate that the KRAS 3'UTR polymorphism may predict for cetuximab responsiveness in KRASwt mCRC patients, which warrants validation in other clinical trials.
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Regiones no Traducidas 3' , Anticuerpos Monoclonales/uso terapéutico , Antineoplásicos/uso terapéutico , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/genética , Genes ras , MicroARNs/genética , Adulto , Anciano , Anciano de 80 o más Años , Anticuerpos Monoclonales Humanizados , Sitios de Unión , Cetuximab , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mutación , Polimorfismo GenéticoRESUMEN
AIMS/HYPOTHESIS: Insulin action is purportedly modulated by Drosophila tribbles homologue 3 (TRIB3), which in vitro prevents thymoma viral proto-oncogene (AKT) and peroxisome proliferator-activated receptor-γ (PPAR-γ) activation. However, the physiological impact of TRIB3 action in vivo remains controversial. METHODS: We investigated the role of TRIB3 in rats treated with either a control or Trib3 antisense oligonucleotide (ASO). Tissue-specific insulin sensitivity was assessed in vivo using a euglycaemic-hyperinsulinaemic clamp. A separate group was treated with the PPAR-γ antagonist bisphenol-A-diglycidyl ether (BADGE) to assess the role of PPAR-γ in mediating the response to Trib3 ASO. RESULTS: Trib3 ASO treatment specifically reduced Trib3 expression by 70% to 80% in liver and white adipose tissue. Fasting plasma glucose, insulin concentrations and basal rate of endogenous glucose production were unchanged. However, Trib3 ASO increased insulin-stimulated whole-body glucose uptake by ~50% during the euglycaemic-hyperinsulinaemic clamp. This was attributable to improved skeletal muscle glucose uptake. Despite the reduction of Trib3 expression, AKT2 activity was not increased. Trib3 ASO increased white adipose tissue mass by 70% and expression of Ppar-γ and its key target genes, raising the possibility that Trib3 ASO improves insulin sensitivity primarily in a PPAR-γ-dependent manner. Co-treatment with BADGE blunted the expansion of white adipose tissue and abrogated the insulin-sensitising effects of Trib3 ASO. Finally, Trib3 ASO also increased plasma HDL-cholesterol, a change that persisted with BADGE co-treatment. CONCLUSIONS/INTERPRETATION: These data suggest that TRIB3 inhibition improves insulin sensitivity in vivo primarily in a PPAR-γ-dependent manner and without any change in AKT2 activity.
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Resistencia a la Insulina/fisiología , PPAR gamma/metabolismo , Proteínas Quinasas/metabolismo , Animales , Compuestos de Bencidrilo , Diabetes Mellitus Tipo 2/metabolismo , Modelos Animales de Enfermedad , Compuestos Epoxi/farmacología , Técnica de Clampeo de la Glucosa , Immunoblotting , Resistencia a la Insulina/genética , Masculino , Oligonucleótidos Antisentido/genética , PPAR gamma/antagonistas & inhibidores , PPAR gamma/genética , Proteínas Quinasas/genética , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Ratas , Ratas Sprague-Dawley , Reacción en Cadena de la Polimerasa de Transcriptasa InversaRESUMEN
BACKGROUND: Flow chambers allow the ex vivo study of platelet response to defined surfaces at controlled wall shear stresses. However, most assays require 1-10 mL of blood and are poorly suited for murine whole blood experiments. OBJECTIVE: To measure murine platelet deposition and stability in response to focal zones of prothrombotic stimuli using 100 microL of whole blood and controlled flow exposure. METHODS: Microfluidic methods were used for patterning acid-soluble collagen in 100 microm x 100 microm patches and creating flow channels with a volume of 150 nL. Within 1 min of collection into PPACK and fluorescent anti-mouse CD41 mAb, whole blood from normal mice or from mice deficient in the integrin alpha(2) subunit was perfused for 5 min over the patterned collagen. Platelet accumulation was measured at venous and arterial wall shear rates. After 5 min, thrombus stability was measured with a 'shear step-up' to 8000 s(-1). RESULTS: Wild-type murine platelets adhered and aggregated on collagen in a biphasic shear-dependent manner with increased deposition from 100 to 400 s(-1), but decreased deposition at 1000 s(-1). Adhesion to patterned collagen was severely diminished for platelets lacking a functional alpha(2)beta(1) integrin. Those integrin alpha(2)-deficient platelets that did adhere were removed from the surface when challenged to shear step-up. PAR4 agonist (AYPGKF) treatment of the thrombus at 5 min enhanced aggregate stability during the shear step-up. CONCLUSIONS: PAR4 signaling enhances aggregate stability by mechanisms independent of other thrombin-dependent pathways such as fibrin formation.