RESUMEN
OBJECTIVE: To evaluate racial and ethnic disparities in utilization of total knee arthroplasty (TKA) in relation to demographic, health, and socioeconomic status variables. DESIGN: Prospective study of 102,767 Women's Health Initiative postmenopausal women initially aged 50-79, examining utilization rates of primary TKA between non-Hispanic Black/African American, non-Hispanic White, and Hispanic/Latina women (hereafter referred to as Black, White, and Hispanic). A total of 8,942 Black, 3,405 Hispanic, and 90,420 White women with linked Medicare claims data were followed until time of TKA, death, or transition from fee-for-service coverage. Absolute disparities were determined using utilization rates by racial/ethnic group and relative disparities quantified using multivariable hazards models in adjusting for age, arthritis, joint pain, mobility disability, body mass index, number of comorbidities, income, education, neighborhood socioeconomic status (SES), and geographic region. RESULTS: TKA utilization was higher among White women (10.7/1,000 person-years) compared to Black (8.5/1,000 person-years) and Hispanic women (7.6/1,000 person-years). Among women with health indicators for TKA including diagnosis of arthritis, moderate to severe joint pain, and mobility disability, Black and Hispanic women were significantly less likely to undergo TKA after adjusting for age [Black: HR (95% confidence interval) = 0.70 (0.63-0.79); Hispanic: HR = 0.58 (0.44-0.77)]. Adjustment for SES modestly attenuated the measured disparity, but significant differences remained [Black: HR = 0.75 (0.67-0.89); Hispanic: HR = 0.65 (0.47-0.89)]. CONCLUSIONS: Compared to White women, Black and Hispanic women were significantly less likely to undergo TKA after considering need and appropriateness for TKA and SES. Further investigation into personal-level and provider-level factors that may explain these disparities is warranted.
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Artralgia/cirugía , Artritis Reumatoide/cirugía , Artroplastia de Reemplazo de Rodilla/estadística & datos numéricos , Etnicidad/estadística & datos numéricos , Disparidades en Atención de Salud/etnología , Limitación de la Movilidad , Osteoartritis de la Rodilla/cirugía , Negro o Afroamericano/estadística & datos numéricos , Anciano , Artralgia/epidemiología , Artritis Reumatoide/epidemiología , Femenino , Hispánicos o Latinos/estadística & datos numéricos , Humanos , Medicare , Persona de Mediana Edad , Osteoartritis de la Rodilla/epidemiología , Modelos de Riesgos Proporcionales , Clase Social , Estados Unidos/epidemiología , Población Blanca/estadística & datos numéricos , MujeresRESUMEN
BACKGROUND: Hemorrhage and blood loss are still among the main causes of preventable death. Global hemostatic assays are useful point-of-care test (POCT) devices to rapidly detect cumulative effects of plasma factors and platelets on coagulation. Thromboelastography (TEG) and Thromboelastometry (ROTEM) are established methods in many anesthesiological departments for guided hemostatic treatment. However, von Willebrand disease remains undetected by standard ROTEM, especially during emergency care, despite being the most prevalent congenital hemostatic disorder. METHODS: In our monocentric cohort pilot study we focused on hemostatic challenges associated with von Willebrand disease. Twenty-seven patients with suspected von Willebrand disease were included. We modified the routine ROTEM assay by adding a preincubation with ristocetin and commercially available plasma-derived von Willebrand factor to identify clinically relevant von Willebrand disease (VWD). RESULTS: Addition of von Willebrand factor to the ristocetin assay of a VWD type 3 patient restored the reaction of the whole blood probe to match the response of a healthy person. Our modified ROTEM assay with ristocetin (Ricotem) showed that all high responders (n = 7) had VWD. In the low responder group (n = 16) - 10 of 16 had VWD and in the normal responder group (n = 5), 2 of 5 had mild type 1 VWD. CONCLUSIONS: This new modification of the standard ROTEM assay enables the detection of otherwise unnoticed critical von Willebrand disease based on alterations in clot formation and might serve as a novel approach to reliably assess severe VWD patients by platelet-mediated blood clotting in an emergency setting. We recommend incorporating this new VWD-focused screening tool into the current ROTEM-based management algorithm of acute microvascular bleeding.
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Servicio de Urgencia en Hospital , Pruebas en el Punto de Atención , Tromboelastografía/métodos , Enfermedades de von Willebrand/diagnóstico , Adolescente , Adulto , Algoritmos , Niño , Preescolar , Estudios de Cohortes , Femenino , Pruebas Hematológicas/métodos , Humanos , Lactante , Masculino , Persona de Mediana Edad , Proyectos Piloto , Sistemas de Atención de Punto , Ristocetina/administración & dosificación , Adulto Joven , Factor de von Willebrand/metabolismoRESUMEN
Paediatric asthma exacerbations are often caused by rhinovirus (RV). Moreover, 25(OH)-vitamin D3 (VitD3) deficiency during infancy was found associated with asthma. Here, we investigated the innate immune responses to RV and their possible modulation by 25(OH)-VitD3 serum levels in a preschool cohort of children with and without asthma. The innate lymphoid cell type 2 (ILC2)-associated marker, ST2, was found up-regulated in the blood cells of asthmatic children with low serum levels of 25(OH)-VitD3 in the absence of RV in their airways. Furthermore, in blood cells from control and asthmatic children with RV in their airways, soluble (s) ST2 (sST2) protein was found reduced. Asthmatic children with low 25(OH)-VitD3 in serum and with RV in vivo in their airways at the time of the analysis had the lowest sST2 protein levels in the peripheral blood compared to control children without RV and high levels of 25(OH)-VitD3. Amphiregulin (AREG), another ILC2-associated marker, was found induced in the control children with RV in their airways and low serum levels of 25(OH)-VitD3. In conclusion, the anti-inflammatory soluble form of ST2, also known as sST2, in serum correlated directly with interleukin (IL)-33 in the airways of asthmatic children. Furthermore, RV colonization in the airways and low serum levels of 25(OH)-VitD3 were found to be associated with down-regulation of sST2 in serum in paediatric asthma. These data indicate a counter-regulatory role of 25(OH)-VitD3 on RV-induced down-regulation of serum sST2 in paediatric asthma, which is relevant for the therapy of this disease.
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Asma/inmunología , Colecalciferol/sangre , Resfriado Común/inmunología , Proteína 1 Similar al Receptor de Interleucina-1/metabolismo , Leucocitos Mononucleares/fisiología , Sistema Respiratorio/metabolismo , Rhinovirus/inmunología , Células Cultivadas , Niño , Preescolar , Estudios de Cohortes , Progresión de la Enfermedad , Femenino , Humanos , Inmunidad Innata , Proteína 1 Similar al Receptor de Interleucina-1/genética , Interleucina-33/metabolismo , Leucocitos Mononucleares/virología , Masculino , Regulación hacia ArribaRESUMEN
BACKGROUND AND OBJECTIVES: Short-term storage of leukapheresis products used for immunotherapeutic mononuclear cell (MNC) products is a frequent event. The analysis of time-related metabolic patterns enables the characterization of storage-related effects in MNCs and the hypothesis-based optimization of the MNC medium. MATERIALS AND METHODS: The MNC products from seven leukapheresis procedures were stored within a closed bag system for 48 h. Concentrations of amino acids, biogenic amines, phospho- and sphingolipids and hexoses in the medium were measured by targeted metabolomics. The viability of MNC subpopulations was assayed by Annexin V (AnV) and JC-1 staining. RESULTS: Glucose depletion and a significant change of the acylcarnitine profile are early events within the first 24 h of storage. In contrast, for most amino acids, the maximum increase was observed at 48 h of storage as mirrored by an increase in the amino acid levels by a mean factor of 1·2 (1·3, 2·0) after 6 h (24 h, 48 h, respectively). This was except for the concentrations of glutamine and lysine, which did not change significantly. The taurine concentration showed a twofold increase within the first 24 h and remained constant thereafter. The steepest increase in AnV+ and 7-AAD+ CD4+ T cells was found between 24 and 48 h. CONCLUSION: The time-course of apoptosis and metabolic patterns in the MNC products demonstrate that 24 h of storage is a decisive time-point, as afterwards key metabolic pathways showed nonlinear detrimental changes. Optimization of storage by supplementation of specific substrates demands therefore an early intervention.
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Conservación de la Sangre , Leucocitos Mononucleares/metabolismo , Aminas/análisis , Aminoácidos/análisis , Apoptosis , Linfocitos T CD4-Positivos/citología , Linfocitos T CD4-Positivos/metabolismo , Carnitina/análogos & derivados , Carnitina/análisis , Cromatografía Líquida de Alta Presión , Glucosa/metabolismo , Humanos , Leucaféresis , Leucocitos Mononucleares/citología , Metabolómica , Fosfolípidos/análisis , Esfingolípidos/análisis , Espectrometría de Masas en Tándem , Factores de TiempoRESUMEN
BACKGROUND: The physical demands of firefighting require both cardiovascular and muscular fitness, which both decline with age. While much has been published on age-related changes among male firefighters (FFs), data on female FFs are lacking. AIMS: To describe cardiorespiratory fitness (CRF) and muscular fitness in a sample of female career FFs ranging in age from 25 to 60 years and determine whether ageing affects their achievement of the current recommended professional CRF standards of 12 metabolic equivalents (METs). METHODS: Data were collected on female FFs over an 11-year period. A cross-sectional analysis using one-way analysis of variance with Bonferroni post hoc comparisons was used to compare age groups. RESULTS: There were 96 study participants. Maximum METs was significantly higher (P < 0.01) in the 25- to 34-year age group (14.6 ± 2.1) compared with the 35-44 age group (12.9 ± 2.0 METs) and the 45-54 age group (12.2 ± 1.8 METs, P < 0.001). While the mean values of all measured age groups met or exceeded the 12-MET profession standard, as many as one-third of FFs <45 years of age and 43% of FFs >45 years of age fell below the benchmark of 12 METs. Muscular fitness as measured by maximum number of push-ups, sit-ups and back endurance was not significantly different between age groups. CONCLUSIONS: Fire departments should recognize and take steps to ensure all female FFs maintain CRF and muscular fitness throughout their careers.
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Envejecimiento/fisiología , Bomberos/estadística & datos numéricos , Aptitud Física/fisiología , Adulto , California , Estudios Transversales , Prueba de Esfuerzo/métodos , Prueba de Esfuerzo/estadística & datos numéricos , Femenino , Humanos , Persona de Mediana EdadRESUMEN
Physical activity is beneficial for many aspects of health but is associated with a risk of injury. Studies that assess causal risk factors of injury and reinjury provide valuable information to help develop and improve injury prevention programs. However, the underlying assumptions of analytical approaches often used to estimate causal factors in injury and subsequent injury research are often violated. This means that ineffective or even harmful interventions could be proposed because the underlying analyses produced unreliable or invalid causal effect estimates. We describe an adapted version of the multistate framework [multistate framework for the analysis of subsequent injury in sport (M-FASIS)] that makes investigator choices more transparent with respect to outcome and healing time. In addition, M-FASIS incorporates all previous sport injury analytical frameworks and accounts for injuries or conditions that heal or do not heal to 100%, acute and overuse injuries, illnesses, and competing event outcomes.
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Traumatismos en Atletas/epidemiología , Traumatismos en Atletas/etiología , Modelos Teóricos , Traumatismos en Atletas/prevención & control , Humanos , Recurrencia , Medición de Riesgo/métodos , Factores de RiesgoRESUMEN
BACKGROUND: Autosomal recessive congenital ichthyoses (ARCIs) are keratinization disorders caused by impaired skin barrier function. Mutations in the genes encoding the lipoxygenases 12R-LOX and eLOX-3 are the second most common cause of ARCIs. In recent years, human skin equivalents recapitulating the ARCI phenotype have been established. OBJECTIVES: To develop a murine organotypic tissue culture model for ARCI. METHODS: Epidermal keratinocytes were isolated from newborn 12R-LOX-deficient mice and cocultivated with mouse dermal fibroblasts embedded in a scaffold of native collagen type I. RESULTS: With this experimental set-up the keratinocytes formed a well-organized multilayered stratified epithelium resembling skin architecture in vivo. All epidermal layers were present and the keratinocytes within showed the characteristic morphological features. Markers for differentiation and maturation indicated regular epidermal morphogenesis. The major components of epidermal structures were expressed, and were obviously processed and assembled properly. In contrast to their wild-type counterparts, 12R-LOX-deficient skin equivalents showed abnormal vesicular structures in the upper epidermal layers correlating with altered lipid composition and increased transepidermal water loss, comparable with 12R-LOX-deficient mice. CONCLUSIONS: The mouse skin equivalents faithfully recapitulate the 12R-LOX-deficient phenotype observed in vivo, classifying them as appropriate in vitro models to study molecular mechanisms involved in the development of ARCI and to evaluate novel therapeutic agents. In contrast to existing human three-dimensional skin models, the generation of these murine models is not constrained by a limited supply of material and does not depend on in vitro expansion and/or genetic manipulations that could result in inadvertent genotypic and phenotypic alterations.
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Modelos Animales de Enfermedad , Ictiosis Lamelar/genética , Animales , Araquidonato 12-Lipooxigenasa/deficiencia , Técnicas de Cultivo de Célula/métodos , Epidermis/fisiología , Queratinocitos/fisiología , Lípidos/fisiología , Ratones , Ingeniería de TejidosAsunto(s)
Araquidonato 12-Lipooxigenasa/deficiencia , Ceramidas/metabolismo , Ictiosis/metabolismo , Lipooxigenasa/deficiencia , Piel/química , Araquidonato 12-Lipooxigenasa/genética , Araquidonato 5-Lipooxigenasa/genética , Estudios de Casos y Controles , Niño , Homocigoto , Humanos , Mutación/genéticaRESUMEN
BACKGROUND: The transfusion of packed red blood cells (PRBC) is associated with various side effects, including storage damage to PRBCs. The cells change their structure, releasing potassium as well as lactate. Mechanical rinsing, available in many hospitals, is able to remove toxic substances and possibly minimizes the negative side effects of transfusion. OBJECTIVE: The primary aim of our study was to improve the quality of PRBCs before transfusion. The effects of different washing solutions on PRBC quality were analyzed. MATERIAL AND METHODS: This in vitro study compares 30 mechanically washed PRBCs. They were either processed with standard normal saline 0.9% (nâ¯= 15, N group) or a hemofiltration solution containing 4â¯mmol/l potassium (nâ¯= 15, HF group) by a mechanical rinsing device (Xtra, LivaNova, Munich, Germany). A subgroup analysis was performed based on the storage duration of the processed PRBCs (7, 14, 37 days). Samples were taken before washing (EKprä), immediately after washing (EKpost) and 10â¯h later (EKpost10h), after storage in the "wash medium" at room temperature. Concentrations of ATP (probability of survival in transfused erythrocytes), lactate, citrate and electrolytes (potassium, sodium, chloride, calcium) were tested. RESULTS AND CONCLUSION: Mechanical rinsing improves pretransfusion quality of PRBC. Washing with a hemofiltration solution results in a more physiological electrolyte composition. Even 10â¯h after mechanical rinsing with a hemofiltration solution, the quality of 37-day-old PRBC is comparable to young PRBC that have been stored for 7 days and have not been washed. Washing stored PRBC increases the ATP content, which subsequently leads to an increased probability of survival of red cells after transfusion.
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Conservación de la Sangre , Eritrocitos , Conservación de la Sangre/métodos , Eritrocitos/química , Potasio/análisis , Electrólitos/análisis , Adenosina Trifosfato/análisis , Lactatos/análisisRESUMEN
BACKGROUND: There is some evidence for coagulation disorders, e.g. decreased coagulation factor activity or thrombocytopenia, related to the use of antiepileptic drugs, mainly associated with valproate. The aim of our study was to evaluate the influence of valproate on thrombin generation. METHOD: Patients with epilepsy receiving multiple anticonvulsant medications either with, or without, valproate were compared. The study group included 90 samples from patients with epilepsy, aged 1.3-20.1 years. Antiepileptic combination therapy without valproate was administered in 50 cases and therapy including valproate in 40 cases. The reference group consisted of 50 non-epileptic patients. Thrombin generation in platelet poor plasma was measured by calibrated automated thrombography. RESULTS: No differences were measured for thrombin generation parameters between controls and patients without valproate therapy. In epileptic patients with valproate therapy, peak height and lag time were significantly lower in comparison to non-epileptic patients. In comparison to epileptic patients without valproate therapy, significant differences were found for lag time and peak time. Patients with valproate therapy had a significantly lower fibrinogen concentration. Platelet counts were decreased in a dose dependent manner. CONCLUSION: No major differences in thrombin generation were found between children on antiepileptic therapy with and without valproate. The decreased fibrinogen levels result in shorter lag time and peak time.
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Anticonvulsivantes/efectos adversos , Epilepsia/sangre , Epilepsia/tratamiento farmacológico , Tromboelastografía/efectos de los fármacos , Trombina/metabolismo , Ácido Valproico/efectos adversos , Adolescente , Anticonvulsivantes/uso terapéutico , Niño , Preescolar , Quimioterapia Combinada , Femenino , Fibrinógeno/metabolismo , Humanos , Lactante , Masculino , Tiempo de Tromboplastina Parcial , Recuento de Plaquetas , Valores de Referencia , Ácido Valproico/uso terapéutico , Adulto JovenRESUMEN
This cross-sectional clinical study was designed to explore the impact of tryptophan-kynurenine and tryptophan-serotonin (5 HT) pathways on reproductive performance during in vitro fertilization (IVF). Paired serum and follicular fluid (FF) samples were obtained from 64 consecutive IVF patients. The analysis was done by using LC-MS/MS. Ovarian hyperstimulation resulted in decreased serum tryptophan (p<0.004), 5-HT (p<0.049) and kynurenine (p<0.001). FF levels of tryptophan (R=0.245, p<0.051), kynurenine (R=0.556, p<0.001) and 5-HT (R=0.523, p<0.001) were positively related to their respective serum levels. Clinical pregnancy was associated with higher serum 5-HT (p<0.045) and FF 5-HT (p<0.020) and lower kynurenine to 5-HT ratio (p<0.024). Chemical pregnancy was also positively related to FF 5-HT (R=0.362, p<0.024). Moreover, there was a direct relationship of the number of mature oocytes to the FF 5-HT (R=0.363, p<0.020) but it was inversely related to FF tryptophan to 5-HT and FF kynurenine to 5-HT ratios (R=-0.389, p<0.016 and R=-0.337, p<0.036, respectively). Multivariate logistic regression revealed that the number of mature oocytes was significantly influenced by FF 5-HT (?=0.473, p<0.001). In IVF patients ovarian hyperstimulation results in a reduction of the availability of tryptophan to catabolic pathways to kynurenine and 5-HT. Outcome measures improved significantly when 5-HT predominated over kynurenine.
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Endometriosis/patología , Fertilización In Vitro/métodos , Quinurenina/metabolismo , Inducción de la Ovulación/métodos , Serotonina/metabolismo , Triptófano/metabolismo , Adulto , Estudios Transversales , Endometriosis/metabolismo , Femenino , Humanos , EmbarazoRESUMEN
BACKGROUND: In patients with phenylketonuria (PKU), the carnitine status may be impaired for metabolic or dietary reasons, including low carnitine intake, a deficient synthesis and acylcarnitine production from phenylalanine (Phe) metabolites. METHODS: Free carnitine and acylcarnitine status was assessed in 30 PKU patients, aged 0.5-36 years, mean age 13.8 years. Our cohort was divided into 2 groups according to the preparations of Phe-free amino acids (AA) prescribed, with or without carnitine supplementation. Daily Phe intake, dosage of AA mixtures and body weight were recorded along with measurements of acylcarnitines in blood spots (by tandem mass spectrometry) and serum AA. Control data were obtained from 50 healthy volunteers (aged 0.2-39 years, mean age 14.2. years). Statistical analysis comprised the t test, ANOVA and Pearson's correlation. RESULTS: PKU patients had lower free carnitine (C0) concentrations than controls (25.82 +/- 7.38 vs. 31.28 +/- 6.17 micromol/l; p < 0.001) and lower octanoyl- and decanoylcarnitine. Mean C0 and acylcarnitine concentrations did not differ between PKU patients taking the various protein substitutes with or without carnitine; mean C0 levels in PKU patients receiving AA enriched with carnitine were still lower compared with controls (p < 0.05). CONCLUSIONS: Actual dietary regimens can not completely normalize the carnitine status; therefore, carnitine levels should be given careful consideration in subjects with PKU.
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Carnitina/sangre , Carnitina/deficiencia , Estado Nutricional , Fenilalanina/administración & dosificación , Fenilcetonurias/dietoterapia , Adolescente , Adulto , Análisis de Varianza , Carnitina/administración & dosificación , Estudios de Casos y Controles , Niño , Preescolar , Estudios de Cohortes , Dieta con Restricción de Proteínas , Femenino , Humanos , Lactante , Masculino , Necesidades Nutricionales , Fenilalanina/sangre , Fenilcetonurias/sangre , Adulto JovenRESUMEN
OBJECTIVE: To assess the impact of maternal smoking during pregnancy (MSDP) on the neonatal hypothalamic-pituitary-adrenal axis. STUDY DESIGN: In a prospective observational study, salivary cortisol and cortisone levels were measured at the fourth day of life during resting conditions and in response to a pain-induced stress event in healthy neonates whose mothers smoked cigarettes during each stage of pregnancy and compared with controls. RESULTS: Neonates in the control group (n=70) exhibited a physiologic stress response with a significant increase in cortisol (1.3 to 2.1 ng ml-1; P<0.05) and cortisone (11.8 to 17.8 ng ml-1; P<0.05) from baseline levels, whereas in neonates from mothers who smoked (n=33), cortisol (0.9 to 0.8 ng ml-1; P=0.77) and cortisone (11.5 to 13.0; P=0.19) stress response was not significantly different from baseline levels. A two-way analysis of variance confirmed these findings in both groups. CONCLUSIONS: Healthy neonates whose mothers smoked during pregnancy show a blunted stress response on the fourth day of life. Thus, MSDP leads to a dysregulation of the HPA axis with continued effects in neonatal life. This might explain long-term consequences of MSDP such as overweight, diabetes mellitus and modification of blood pressure control mechanisms in adult life.
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Fumar Cigarrillos/efectos adversos , Sistema Hipotálamo-Hipofisario/fisiopatología , Sistema Hipófiso-Suprarrenal/fisiopatología , Efectos Tardíos de la Exposición Prenatal/fisiopatología , Estrés Fisiológico , Adolescente , Adulto , Estudios de Casos y Controles , Femenino , Humanos , Hidrocortisona/análisis , Recién Nacido , Unidades de Cuidado Intensivo Neonatal , Masculino , Madres , Embarazo , Estudios Prospectivos , Análisis de Regresión , Saliva/química , Adulto JovenRESUMEN
Immune dysregulation is a common feature of myelodysplastic syndromes (MDS) and chronic myelomonocytic leukemia (CMML), particularly in early stages. However, the genetic basis remains poorly understood. We recently reported that macrophages from mice deficient in tet methylcytosine dioxygenase 2 (Tet2), a model of MDS/CMML, are hyperinflammatory and have increased expression of arginase 1 (Arg1). In macrophages and myeloid derived suppressor cells (MDSCs) expression of Arg1 contributes to T-cell suppression and immune evasion by L-arginine depletion, in the setting of chronic inflammation and cancer. Since human MDS and CMML are driven by TET2 mutations and associated with chronic inflammation, we hypothesized that arginase enzymatic activity and ARG1 expression would be increased in human MDS/CMML bone marrow. Elevated arginase activity was observed in bone marrow mononuclear cells of MDS and CMML patients with lower-grade features. Immunohistochemical studies confirmed that myelomonocytic cells overexpress ARG1. Additionally, mutations in the epigenetic regulators TET2 and DNMT3A corresponded to high ARG1 expression and activity. These findings suggest ARG1 is a biomarker of immune dysregulation in early MDS and CMML. Recent murine findings have implicated Tet2 and Dnmt3a in regulation of innate immunity. Our study suggests similar changes may be driven by human TET2 and DNMT3A mutations.
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Arginasa/genética , ADN (Citosina-5-)-Metiltransferasas/genética , Proteínas de Unión al ADN/genética , Leucemia Mielomonocítica Crónica/genética , Mutación , Síndromes Mielodisplásicos/genética , Proteínas Proto-Oncogénicas/genética , Biomarcadores de Tumor/metabolismo , Médula Ósea/enzimología , Estudios de Casos y Controles , Estudios de Cohortes , ADN Metiltransferasa 3A , Dioxigenasas , Epigénesis Genética , Femenino , Humanos , Leucemia Mielomonocítica Crónica/inmunología , Leucemia Mielomonocítica Crónica/patología , Masculino , Síndromes Mielodisplásicos/inmunología , Síndromes Mielodisplásicos/patología , Clasificación del Tumor , Microambiente TumoralRESUMEN
Transgenic mice expressing the polyomavirus (PyV) middle T antigen (MT) develop multifocal mammary tumors which frequently metastasize to the lung. The potent transforming activity of PyV MT is correlated with its capacity to activate and associate with a number of signaling molecules, including the Src family tyrosine kinases, the 85-kDa Src homology 2 subunit of the phosphatidylinositol 3' (PI-3') kinase, and the Shc adapter protein. To uncover the role of these signaling proteins in MT-mediated mammary tumorigenesis, we have generated transgenic mice that express mutant PyV MT antigens decoupled from either the Shc or the PI-3' kinase signaling pathway. In contrast to the rapid induction of metastatic mammary tumors observed in the strains expressing wild-type PyV MT, mammary epithelial cell-specific expression of either mutant PyV MT resulted in the induction of extensive mammary epithelial hyperplasias. The mammary epithelial hyperplasias expressing the mutant PyV MT defective in recruiting the PI-3' kinase were highly apoptotic, suggesting that recruitment of PI-3' kinase by MT affects cell survival. Whereas the initial phenotypes observed in both strains were global mammary epithelial hyperplasias, focal mammary tumors eventually arose in all female transgenic mice. Genetic and biochemical analyses of tumorigenesis in the transgenic strains expressing the PyV MT mutant lacking the Shc binding site revealed that a proportion of the metastatic tumors arising in these mice displayed evidence of reversion of the mutant Shc binding site. In contrast, no evidence of reversion of the PI-3' kinase binding site was noted in tumors derived from the strains expressing the PI-3' kinase binding site MT mutant. Tumor progression in both mutant strains was further correlated with upregulation of the epidermal growth factor receptor family members which are known to couple to the PI-3' kinase and Shc signaling pathways. Taken together, these observations suggest that PyV MT-mediated tumorigenesis requires activation of both Shc and PI-3' kinase, which appear to be required for stimulation of cell proliferation and survival signaling pathways, respectively.
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Proteínas Adaptadoras Transductoras de Señales , Proteínas Adaptadoras del Transporte Vesicular , Antígenos Transformadores de Poliomavirus/fisiología , Transformación Celular Neoplásica , Transformación Celular Viral , Neoplasias Mamarias Experimentales/virología , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas/metabolismo , Transducción de Señal , Secuencia de Aminoácidos , Animales , Apoptosis , Secuencia de Bases , Sitios de Unión , Mama/patología , ADN , Progresión de la Enfermedad , Activación Enzimática , Receptores ErbB/biosíntesis , Receptores ErbB/genética , Femenino , Hiperplasia , Masculino , Neoplasias Mamarias Experimentales/química , Neoplasias Mamarias Experimentales/etiología , Ratones , Ratones Transgénicos , Datos de Secuencia Molecular , Mutagénesis , Poliomavirus/fisiología , Proteínas Proto-Oncogénicas/biosíntesis , Proteínas Proto-Oncogénicas/genética , Receptor ErbB-2/biosíntesis , Receptor ErbB-2/genética , Receptor ErbB-3 , Proteínas Adaptadoras de la Señalización Shc , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de Src , Distribución Tisular , Regulación hacia ArribaRESUMEN
The Grb2 and Shc adapter proteins play critical roles in coupling activated growth factor receptors to several cellular signaling pathways. To assess the role of these molecules in mammary epithelial development and tumorigenesis, we have generated transgenic mice which individually express the Grb2 and Shc proteins in the mammary epithelium. Although mammary epithelial cell-specific expression of Grb2 or Shc accelerated ductal morphogenesis, mammary tumors were rarely observed in these strains. To explore the potential role of these adapter proteins in mammary tumorigenesis, mice coexpressing either Shc or Grb2 and a mutant form of polyomavirus middle T (PyV mT) antigen in the mammary epithelium were generated. Coexpression of either Shc or Grb2 with the mutant PyV mT antigen resulted in a dramatic acceleration of mammary tumorigenesis compared to parental mutant PyV mT strain. The increased rate of tumor formation observed in these mice was correlated with activation of the epidermal growth factor receptor family and mitogen-activated protein kinase pathway. These observations suggest that elevated levels of the Grb2 or Shc adapter protein can accelerate mammary tumor progression by sensitizing the mammary epithelial cell to growth factor receptor signaling.
Asunto(s)
Proteínas Adaptadoras Transductoras de Señales , Proteínas Adaptadoras del Transporte Vesicular , Antígenos Transformadores de Poliomavirus/fisiología , Neoplasias Mamarias Experimentales/patología , Proteínas/fisiología , Animales , Antígenos Transformadores de Poliomavirus/genética , Femenino , Proteína Adaptadora GRB2 , Expresión Génica , Vectores Genéticos , Humanos , Virus del Tumor Mamario del Ratón , Ratones , Ratones Transgénicos , Morfogénesis , Biosíntesis de Proteínas , Proteínas/genética , Conejos , Proteínas Adaptadoras de la Señalización Shc , Proteína Transformadora 1 que Contiene Dominios de Homología 2 de SrcRESUMEN
AIM: We investigated the metabolic profiles along with insulin and ghrelin responses following ingestion of various amino acid (AA) substitutes commonly used in the treatment of phenylketonuria to study the effects of added macronutrients. METHODS: Twenty healthy and 6 phenylketonuric adults ingested AA mixtures with or without carbohydrates and fat (Anamix, Easiphen, or p-am 3; 0.35 g AA/kg body weight); milk powder shakes were used for control purposes. Serum AA, glucose, urea, insulin, and ghrelin were measured over 5 h. RESULTS: Peak AA concentrations were achieved at around 60 min postprandially for supplemented AA powders and control shakes, significantly later than for pure AA. Of interest, the mean Phe/Tyr ratio declined by 40-50% in phenylketonuric patients following intake of Easiphen, Anamix, or p-am 3. The insulin peaks, up to 500% as compared with baseline, occurred at 30 min and were approximately 100% higher after intake of AA plus macronutrients. Glucose and urea remained constant. Ghrelin showed a nadir at 60 min, followed by a rise leading to a 30% increase of initial concentrations for pure AA as compared with more constant levels for preparations with macronutrients. CONCLUSION: An oral AA bolus together with macronutrients retards hyperaminoacidemia, displays a higher insulin secretion, normoglycemia, and more stable ghrelin concentrations, whereas the pure AA tested here exerted weaker anabolic effects.
Asunto(s)
Aminoácidos/farmacocinética , Carbohidratos de la Dieta/farmacología , Grasas de la Dieta/farmacología , Insulina/metabolismo , Hormonas Peptídicas/metabolismo , Fenilcetonurias/metabolismo , Administración Oral , Adulto , Área Bajo la Curva , Femenino , Ghrelina , Humanos , Masculino , Fenilcetonurias/dietoterapia , Periodo Posprandial , Urea/sangreRESUMEN
The pneumococcal enzyme-linked immunosorbent assay (ELISA) reference standard serum, lot 89SF, had been in use since 1990 and was replaced with a new reference standard serum, 007sp, in 2013. This serum was generated under an FDA-approved clinical protocol where 278 adult volunteers were immunized with the 23-valent unconjugated polysaccharide vaccine Pneumovax II and a unit of blood was obtained twice within 120 days following immunization. Pooled serum was prepared from the plasma, filled at 6 ml per vial, and lyophilized. Five independent laboratories participated in bridging the serotype-specific IgG assignments of 89SF to 007sp to establish equivalent reference values for 13 pneumococcal capsular serotypes (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, 23F) using the WHO reference ELISA. A subsequent follow-up study established equivalent reference values for an additional seven serotypes (8, 10A, 11A, 12F, 15B, 22F, 33F). In this study, three laboratories assigned weight-based IgG concentrations in micrograms per milliliter of serum to 007sp for four additional serotypes: 2, 9N, 17F, and 20A. This study completes the assignment of serotypes for 89SF to 007sp. In addition, the IgG antibody assignments for a 12-member WHO quality control (QC) serum panel were extended to cover the four additional serotypes. Agreement was excellent, with a concordance correlation coefficient (rc ) of >0.996 when values from each laboratory were compared to the assigned values for the 12 WHO QC sera. The 007sp preparation has replaced 89SF as the pneumococcal reference standard. Sufficient quantities of 007sp are projected to be available for the next 25 years.
RESUMEN
Cancer cells are hallmarked by high proliferation and imbalanced redox consumption and signaling. Various oncogenic pathways such as proliferation and evading cell death converge on redox-dependent signaling processes. Nrf2 is a key regulator in these redox-dependent events and operates in cytoprotection, drug metabolism and malignant progression in cancer cells. Here, we show that patients with primary malignant brain tumors (glioblastomas, WHO °IV gliomas, GBM) have a devastating outcome and overall reduced survival when Nrf2 levels are upregulated. Nrf2 overexpression or Keap1 knockdown in glioma cells accelerate proliferation and oncogenic transformation. Further, activation of the Nrf2-Keap1 signaling upregulates xCT (aka SLC7A11 or system Xc-) and amplifies glutamate secretion thereby impacting on the tumor microenvironment. Moreover, both fostered Nrf2 expression and conversely Keap1 inhibition promote resistance to ferroptosis. Altogether, the Nrf2-Keap1 pathway operates as a switch for malignancy in gliomas promoting cell proliferation and resistance to cell death processes such as ferroptosis. Our data demonstrate that the Nrf2-Keap1 pathway is critical for cancer cell growth and operates on xCT. Nrf2 presents the Achilles' heel of cancer cells and thus provides a valid therapeutic target for sensitizing cancer for chemotherapeutics.
RESUMEN
Activating transcription factor 4 (ATF4) is a critical mediator of metabolic and oxidative homeostasis and cell survival. ATF4 is elevated in response to diverse microenvironmental stresses, including starvation, ER stress damages and exposure to toxic factors. Here we show that ATF4 expression fosters the malignancy of primary brain tumors (WHO grade III and IV gliomas) and increases proliferation and tumor angiogenesis. Hence, ATF4 expression promotes cell migration and anchorage-independent cell growth, whereas siRNA-mediated knockdown of ATF4 attenuates these features of malignancy in human gliomas. Further experiments revealed that ATF4-dependent tumor promoting effects are mediated by transcriptional targeting the glutamate antiporter xCT/SCL7A11 (also known as system Xc-). Thus, xCT is elevated as a consequence of ATF4 activation. We further found evidence that ATF4-induced proliferation can be attenuated by pharmacological or genetic xCT inhibition and ferroptosis inducers such as sorafenib, erastin and GPx4 inhibitor RSL3. Further, fostered xCT expression promotes cell survival and growth in ATF4 knockdown cells. Moreover, increased xCT levels ameliorate sorafenib and erastin-induced ferroptosis. Conversely, ATF4 knockdown renders cells susceptible for erastin, sorafenib and RSL3-induced ferroptosis. We further identified that ATF4 promotes tumor-mediated neuronal cell death which can be alleviated by xCT inhibition. Moreover, elevated ATF4 expression in gliomas promotes tumor angiogenesis. Noteworthy, ATF4-induced angiogenesis could be diminished by ferroptosis inducers erastin and by GPx4 inhibitor RSL3. Our data provide proof-of-principle evidence that ATF4 fosters proliferation and induces a toxic microenvironmental niche. Furthermore, ATF4 increases tumor angiogenesis and shapes the vascular architecture in a xCT-dependent manner. Thus, inhibition of ATF4 is a valid target for diminishing tumor growth and vasculature via sensitizing tumor cells for ferroptosis.