Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 525
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
Nature ; 537(7620): 374-377, 2016 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-27462808

RESUMEN

White dwarfs are compact stars, similar in size to Earth but approximately 200,000 times more massive. Isolated white dwarfs emit most of their power from ultraviolet to near-infrared wavelengths, but when in close orbits with less dense stars, white dwarfs can strip material from their companions and the resulting mass transfer can generate atomic line and X-ray emission, as well as near- and mid-infrared radiation if the white dwarf is magnetic. However, even in binaries, white dwarfs are rarely detected at far-infrared or radio frequencies. Here we report the discovery of a white dwarf/cool star binary that emits from X-ray to radio wavelengths. The star, AR Scorpii (henceforth AR Sco), was classified in the early 1970s as a δ-Scuti star, a common variety of periodic variable star. Our observations reveal instead a 3.56-hour period close binary, pulsing in brightness on a period of 1.97 minutes. The pulses are so intense that AR Sco's optical flux can increase by a factor of four within 30 seconds, and they are also detectable at radio frequencies. They reflect the spin of a magnetic white dwarf, which we find to be slowing down on a 107-year timescale. The spin-down power is an order of magnitude larger than that seen in electromagnetic radiation, which, together with an absence of obvious signs of accretion, suggests that AR Sco is primarily spin-powered. Although the pulsations are driven by the white dwarf's spin, they mainly originate from the cool star. AR Sco's broadband spectrum is characteristic of synchrotron radiation, requiring relativistic electrons. These must either originate from near the white dwarf or be generated in situ at the M star through direct interaction with the white dwarf's magnetosphere.

2.
Phys Rev Lett ; 115(17): 175301, 2015 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-26551122

RESUMEN

Long-range order in quantum many-body systems is usually associated with equilibrium situations. Here, we experimentally investigate the quasicondensation of strongly interacting bosons at finite momenta in a far-from-equilibrium case. We prepare an inhomogeneous initial state consisting of one-dimensional Mott insulators in the center of otherwise empty one-dimensional chains in an optical lattice with a lattice constant d. After suddenly quenching the trapping potential to zero, we observe the onset of coherence in spontaneously forming quasicondensates in the lattice. Remarkably, the emerging phase order differs from the ground-state order and is characterized by peaks at finite momenta ±(π/2)(ℏ/d) in the momentum distribution function.

3.
Br J Anaesth ; 113(4): 585-95, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25064078

RESUMEN

BACKGROUND: We aimed to create a theoretical tool to model the effect of three haemostatic agents containing fibrinogen (therapeutic plasma, cryoprecipitate, and fibrinogen concentrate) on the patient's plasma fibrinogen level. METHODS: A mathematical model was developed step-wise. The relationship between the amount of haemostatic agent and plasma fibrinogen level was plotted for each agent. A fibrinogen concentration simulator (FCS(amount)) was developed, where the amount of haemostatic agent was calculated from patient characteristics, agent characteristics, and target plasma fibrinogen level. Refinements were introduced so that (i) FCS(amount) would account for in vivo fibrinogen recovery, (ii) circulatory volume would not increase ad infinitum with increasing amounts, and (iii) red blood cells would be included in the simulation if haematocrit decreased below a certain level. A second FCS (FCS(level)) was created to calculate fibrinogen levels resulting from specified amounts of haemostatic agents. RESULTS: Fibrinogen concentration in haemostatic agents has a critical impact on their ability to increase patients' fibrinogen levels. If the target plasma fibrinogen level approaches the concentration of the fibrinogen source, the required amounts increase exponentially; it is impossible to achieve a target above the concentration of the fibrinogen source. CONCLUSIONS: We successfully developed two theoretical tools answering the questions: 'How much therapeutic plasma, cryoprecipitate, or fibrinogen concentrate would be needed to achieve a specified target fibrinogen level?' and 'What would be the resultant fibrinogen level for a specified amount of haemostatic agent?' The current tools are not intended for clinical application, but they are potentially useful for educational purposes.


Asunto(s)
Fibrinógeno/uso terapéutico , Hemostáticos/uso terapéutico , Plasma , Volumen Sanguíneo , Estatura/fisiología , Simulación por Computador , Relación Dosis-Respuesta a Droga , Eritrocitos/fisiología , Fibrinógeno/administración & dosificación , Fibrinógeno/análisis , Hematócrito , Hemostáticos/administración & dosificación , Hemostáticos/química , Humanos , Modelos Teóricos , Plasma/química
4.
Phys Rev Lett ; 110(20): 205301, 2013 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-25167423

RESUMEN

We experimentally and numerically investigate the expansion of initially localized ultracold bosons in homogeneous one- and two-dimensional optical lattices. We find that both dimensionality and interaction strength crucially influence these nonequilibrium dynamics. While the atoms expand ballistically in all integrable limits, deviations from these limits dramatically suppress the expansion and lead to the appearance of almost bimodal cloud shapes, indicating diffusive dynamics in the center surrounded by ballistic wings. For strongly interacting bosons, we observe a dimensional crossover of the dynamics from ballistic in the one-dimensional hard-core case to diffusive in two dimensions, as well as a similar crossover when higher occupancies are introduced into the system.

5.
J Chem Phys ; 138(1): 014306, 2013 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-23298040

RESUMEN

By means of density functional theory, we have studied the electronic structure and vibronic properties of single neutral NiPc, PdPc, and PtPc molecules and their singly and doubly ionized cations and anions. In particular, the vibronic couplings and reorganization energies of all systems are compared. Partitioning of the reorganization energy, corresponding to the photoelectron spectra of the first and second ionizations of studied molecules, into normal mode contributions shows that the major contributions are due to several vibrational modes with a(1g) symmetry and energies lower than 1600 cm(-1). The results reveal that the reorganization energy due to the singly positive ionization in the studied molecules is up to about one order of magnitude less than other reorganization energies. This makes these metal phthalocyanines, from the perspective of intramolecular reorganization energies, attractive as electron donor for intramolecular electron transfer in electron acceptor-donor systems.

6.
Int J Obes (Lond) ; 36(12): 1585-90, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22290538

RESUMEN

OBJECTIVE: Obesity and chronic kidney disease (CKD) have emerged as major public health problems. We aimed to examine: (a) lifestyle and behavioral factors, (b) factors related to pursuing weight loss and (c) weight loss modalities pursued by CKD and non-CKD individuals who are overweight and obese. METHODS: Cross-sectional analysis of 10,971 overweight and obese adult participants in the National Health and Nutrition Examination Surveys conducted between 1999 and 2006. We examined the differences in lifestyle and behavioral factors between CKD and non-CKD participants and factors associated with pursuing weight loss using survey regression models. RESULTS: The total daily energy intake of the CKD population was lower than the non-CKD group (1987 kcal per day versus 2063 kcal per day, P=0.02) even after adjusting for relevant covariates. However, the percentage of energy derived from protein was similar between the groups. Sixty six percent of the CKD population did not meet the minimum recommended leisure time physical activity goals compared with 57% among non-CKD (P<0.001). Fifty percent of CKD participants pursued weight loss (vs fifty-five percent of non-CKD individuals, P=0.01), but the presence of CKD was not independently associated with the pursuit of weight loss in the multivariate model. Among participants pursuing weight loss, modalities including dietary interventions utilized by CKD and non-CKD participants were similar. Eight percent of CKD participants used medications to promote weight loss. CONCLUSIONS: Among the overweight and obese population, lifestyle and behavioral factors related to obesity and weight loss are similar between CKD and non-CKD participants. Insufficient data exist on the beneficial effects of intentional weight loss in CKD and these data show that a significant proportion of the CKD population use diets that may have high-protein content and medications to promote weight loss that may be harmful. Future clinical trials evaluating the efficacy and optimal modalities to treat obesity in the CKD population are warranted.


Asunto(s)
Sobrepeso/epidemiología , Sobrepeso/prevención & control , Insuficiencia Renal Crónica/complicaciones , Insuficiencia Renal Crónica/epidemiología , Pérdida de Peso , Índice de Masa Corporal , Restricción Calórica , Estudios Transversales , Ingestión de Energía , Ejercicio Físico , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Intención , Masculino , Persona de Mediana Edad , Encuestas Nutricionales , Obesidad/epidemiología , Obesidad/prevención & control , Sobrepeso/complicaciones , Estados Unidos/epidemiología
7.
Clin Exp Rheumatol ; 30(1): 45-50, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22274638

RESUMEN

OBJECTIVES: Psoriatic arthritis (PsA) may progress to joint damage. Determining clinical predictors of joint damage assessed by radiography is important. The aim of this study was to determine clinical factors as possible predictors for radiological damage in hands and feet of PsA patients with a 12-month follow-up. METHODS: We conducted a retrospective study on 53 PsA patients who were taking disease-modifying anti-rheumatic drugs (DMARDs) and/or tumour necrosis factor (TNF)-alpha-blockers at a fixed dosage. The patients were observed in 118 follow-up visits (intervals of 12 months ± 3 months), according to a clinical and radiological protocol which included the documentation of the number of swollen and tender joints in hands and feet, the applied therapy, psoriasis, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and global health assessment. Outcome was defined as radiographic damage of hands and feet (Ratingen score). For the statistical analysis the Chi-Square test for 2x2 crosstables (with Fisher's correction, as required) was used. RESULTS: Progressive radiological damage was more frequent among patients with an increasing swollen joint count (8 of 26 visits; 30.8%) than among those with a stable or decreased number of swollen joints (5 of 89 visits; 5.6%; p=0.001). The analysis of the patients stratified into the different treatment modalities resulted in a significant higher rate of radiological progress (20.8%) in patients on DMARD therapy compared with TNF-alpha blocking agents (0%) (p=0.009). CONCLUSIONS: During a 12-month follow-up of PsA patients, an increasing number of swollen joints heralds progression of radiological damage. TNF-alpha-blocker therapy appears to be superior to DMARDs in the protection from radiological progress.


Asunto(s)
Artritis Psoriásica/diagnóstico por imagen , Pie/diagnóstico por imagen , Mano/diagnóstico por imagen , Articulaciones/patología , Adulto , Anciano , Antirreumáticos/uso terapéutico , Artritis Psoriásica/tratamiento farmacológico , Artritis Psoriásica/patología , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Pie/patología , Mano/patología , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Radiografía , Estudios Retrospectivos , Resultado del Tratamiento , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores
8.
Clin Infect Dis ; 52(6): 717-25, 2011 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-21293047

RESUMEN

BACKGROUND: Patients with diabetes mellitus are more prone to bacterial sepsis, but there are conflicting data on whether outcomes are worse in diabetics after presentation with sepsis. Glyburide is an oral hypoglycemic agent used to treat diabetes mellitus. This K(ATP)-channel blocker and broad-spectrum ATP-binding cassette (ABC) transporter inhibitor has broad-ranging effects on the immune system, including inhibition of inflammasome assembly and would be predicted to influence the host response to infection. METHODS: We studied a cohort of 1160 patients with gram-negative sepsis caused by a single pathogen (Burkholderia pseudomallei), 410 (35%) of whom were known to have diabetes. We subsequently studied prospectively diabetics with B. pseudomallei infection (n = 20) to compare the gene expression profile of peripheral whole blood leukocytes in patients who were taking glyburide against those not taking any sulfonylurea. RESULTS: Survival was greater in diabetics than in nondiabetics (38% vs 45%, respectively, P = .04), but the survival benefit was confined to the patient group taking glyburide (adjusted odds ratio .47, 95% confidence interval .28-.74, P = .005). We identified differential expression of 63 immune-related genes (P = .001) in patients taking glyburide, the sum effect of which we predict to be antiinflammatory in the glyburide group. CONCLUSIONS: We present observational evidence for a glyburide-associated benefit during human melioidosis and correlate this with an anti-inflammatory effect of glyburide on the immune system.


Asunto(s)
Antiinflamatorios/administración & dosificación , Gliburida/administración & dosificación , Melioidosis/tratamiento farmacológico , Melioidosis/mortalidad , Adulto , Burkholderia pseudomallei/aislamiento & purificación , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Sepsis/tratamiento farmacológico , Sepsis/microbiología , Sepsis/mortalidad , Análisis de Supervivencia , Resultado del Tratamiento
9.
J Trauma ; 71(2 Suppl 3): S337-42, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21814101

RESUMEN

BACKGROUND: Platelets play a central role in hemostasis after trauma. However, the platelet count of most trauma patients does not fall below the normal range (100-450 × 10(9)/L), and as a result, admission platelet count has not been adequately investigated as a predictor of outcome. The purpose of this study was to examine the relationship between admission platelet count and outcomes after trauma. METHODS: A retrospective cohort study of 389 massively transfused trauma patients. Regression methods and the Kruskal-Wallis test were used to test the association between admission platelet count and 24-hour mortality and units of packed red blood cells (PRBCs) transfused. RESULTS: For every 50 × 10(9)/L increase in admission platelet count, the odds of death decreased 17% at 6 hours (p = 0.03; 95% confidence interval [CI], 0.70-0.99) and 14% at 24 hours (p = 0.02; 95% CI, 0.75-0.98). The probability of death at 24 hours decreased with increasing platelet count. For every 50 × 10(9)/L increase in platelet count, patients received 0.7 fewer units of blood within the first 6 hours (p = 0.01; 95% CI, -1.3 to -0.14) and one less unit of blood within the first 24 hours (p = 0.002; 95% CI, -1.6 to -0.36). The mean number of units of PRBCs transfused within the first 6 hours and 24 hours decreased with increasing platelet count. CONCLUSIONS: Admission platelet count was inversely correlated with 24-hour mortality and transfusion of PRBCs. A normal platelet count may be insufficient after severe trauma, and as a result, these patients may benefit from a lower platelet transfusion threshold. Future studies of platelet number and function after injury are needed.


Asunto(s)
Transfusión Sanguínea , Hemorragia/sangre , Hemorragia/mortalidad , Heridas y Lesiones/sangre , Heridas y Lesiones/mortalidad , Adulto , Pruebas Diagnósticas de Rutina , Servicio de Urgencia en Hospital , Femenino , Hemorragia/terapia , Humanos , Masculino , Persona de Mediana Edad , Recuento de Plaquetas , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Resultado del Tratamiento , Heridas y Lesiones/terapia
10.
J Trauma ; 71(2 Suppl 3): S353-7, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21814103

RESUMEN

BACKGROUND: Recent data suggest that massively transfused patients have lower mortality rates when high ratios (>1:2) of plasma or platelets to red blood cells (RBCs) are used. Blunt and penetrating trauma patients have different injury patterns and may respond differently to resuscitation. This study was performed to determine whether mortality after high product ratio massive transfusion is different in blunt and penetrating trauma patients. METHODS: Patients receiving 10 or more units of RBCs in the first 24 hours after admission to one of 23 Level I trauma centers were analyzed. Baseline physiologic and biochemical data were obtained. Univariate and logistic regression analyses were performed. Adjusted mortality in patients receiving high (≥ 1:2) and low (<1:2) ratios of plasma or platelets to RBCs was calculated for blunt and penetrating trauma patients. RESULTS: The cohort contained 703 patients. Blunt injury patients receiving a high ratio of plasma or platelets to RBCs had lower 24-hour mortality (22% vs. 31% for plasma, p = 0.007; 20% vs. 30% for platelets, p = 0.032), but there was no difference in 30-day mortality (40% vs. 44% for plasma, p = 0.085; 37% vs. 44% for platelets, p = 0.063). Patients with penetrating injuries receiving a high plasma:RBC ratio had lower 24-hour mortality (21% vs. 37%, p = 0.005) and 30-day mortality (29% vs. 45%, p = 0.005). High platelet:RBC ratios did not affect mortality in penetrating patients. CONCLUSION: Use of high plasma:RBC ratios during massive transfusion may benefit penetrating trauma patients to a greater degree than blunt trauma patients. High platelet:RBC ratios did not benefit either group.


Asunto(s)
Transfusión de Componentes Sanguíneos , Hemorragia/terapia , Heridas no Penetrantes/mortalidad , Heridas no Penetrantes/terapia , Heridas Penetrantes/mortalidad , Heridas Penetrantes/terapia , Adolescente , Adulto , Recuento de Eritrocitos , Femenino , Hemorragia/sangre , Hemorragia/mortalidad , Humanos , Masculino , Persona de Mediana Edad , Recuento de Plaquetas , Estudios Retrospectivos , Tasa de Supervivencia , Centros Traumatológicos , Resultado del Tratamiento , Heridas no Penetrantes/sangre , Heridas Penetrantes/sangre , Adulto Joven
11.
J Trauma ; 71(2 Suppl 3): S358-63, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21814104

RESUMEN

BACKGROUND: Coagulopathy is present in 25% to 38% of trauma patients on arrival to the hospital, and these patients are four times more likely to die than trauma patients without coagulopathy. Recently, a high ratio of fresh frozen plasma (FFP) to packed red blood cells (PRBCs) has been shown to decrease mortality in massively transfused trauma patients. Therefore, we hypothesized that patients with elevated International Normalized Ratio (INR) on arrival to the hospital may benefit more from transfusion with a high ratio of FFP:PRBC than those with a lower INR. METHODS: Retrospective multicenter cohort study of 437 massively transfused trauma patients was conducted to determine whether the effect of the ratio of FFP:PRBC on death at 24 hours is modified by a patient's admission INR on arrival to the hospital. Contingency tables and logistic regression were used. RESULTS: Trauma patients who arrived to the hospital with an elevated INR had a greater risk of death than those with a lower INR. However, as the ratio of FFP:PRBC transfused increased, mortality decreased similarly between the INR quartiles. CONCLUSIONS: The mortality benefit from a high FFP:PRBC ratio is similar for all massively transfused trauma patients. This is contrary to the current belief that only coagulopathic trauma patients benefit from a high FFP:PRBC ratio. Furthermore, it is unnecessary to determine whether INR is elevated before transfusing a high FFP:PRBC ratio. Future studies are needed to determine the mechanism by which a high FFP:PRBC ratio decreases mortality in all massively transfused trauma patients.


Asunto(s)
Transfusión de Componentes Sanguíneos , Hemorragia/sangre , Hemorragia/mortalidad , Heridas y Lesiones/sangre , Heridas y Lesiones/mortalidad , Adulto , Recuento de Eritrocitos , Femenino , Hemorragia/terapia , Humanos , Relación Normalizada Internacional , Masculino , Persona de Mediana Edad , Plasma , Estudios Retrospectivos , Tasa de Supervivencia , Heridas y Lesiones/terapia , Adulto Joven
12.
J Trauma ; 71(2 Suppl 3): S364-9, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21814105

RESUMEN

BACKGROUND: Improvements in prehospital care and resuscitation have led to increases in the number of severely injured patients who are salvageable. Massive transfusion has been increasingly used. Patients often present with markedly abnormal physiologic and biochemical data. The purpose of this study was to identify objective data that can be used to identify clinical futility in massively transfused trauma patients to allow for early termination of resuscitative efforts. METHODS: A multicenter database was used. Initial physiologic and biochemical data were obtained, and mortality was determined for patients in the 5th and 10th percentiles for each variable. Raw data from the extreme outliers for each variable were also examined to determine whether a point of excessive mortality could be identified. Injury scoring data were also analyzed. A classification tree model was used to look for variable combinations that predict clinical futility. RESULTS: The cohort included 704 patients. Overall mortality was 40.2%. The highest mortality rates were seen in patients in the 10th percentile for lactate (77%) and pH (72%). Survivors at the extreme ends of the distribution curves for each variable were not uncommon. The classification tree analysis failed to identify any biochemical and physiologic variable combination predictive of >90% mortality. Patients older than 65 years with severe head injuries had 100% mortality. CONCLUSION: Consideration should be given to withholding massive transfusion for patients older than 65 years with severe head injuries. Otherwise we did not identify any objective variables that reliably predict clinical futility in individual cases. Significant survival rates can be expected even in patients with profoundly abnormal physiologic and biochemical data.


Asunto(s)
Transfusión Sanguínea , Hemorragia/metabolismo , Hemorragia/fisiopatología , Inutilidad Médica , Heridas y Lesiones/metabolismo , Heridas y Lesiones/fisiopatología , Adulto , Anciano , Femenino , Hemorragia/terapia , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Resucitación , Estudios Retrospectivos , Factores de Riesgo , Tasa de Supervivencia , Heridas y Lesiones/mortalidad , Adulto Joven
13.
J Trauma ; 71(2 Suppl 3): S370-4, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21814106

RESUMEN

BACKGROUND: Improvements in trauma systems and resuscitation have increased survival in severely injured patients. Massive transfusion has been increasingly used in the civilian setting. Objective predictors of mortality have not been well described. This study examined data available in the early postinjury period to identify variables that are predictive of 24-hour- and 30-day mortality in massively transfused trauma patients. METHODS: Massively transfused trauma patients from 23 Level I centers were studied. Variables available on patient arrival that were predictive of mortality at 24 hours were entered into a logistic regression model. A second model was created adding data available 6 hours after injury. A third model evaluated mortality at 30 days. Receiver operating characteristic curves and the Hosmer-Lemeshow test were used to assess model quality. RESULTS: Seven hundred four massively transfused patients were analyzed. The model best able to predict 24-hour mortality included pH, Glasgow Coma Scale score, and heart rate, with an area under the receiver operating characteristic curve (AUROC) of 0.747. Addition of the 6-hour red blood cell requirement increased the AUROC to 0.769. The model best able to predict 30-day mortality included the above variables plus age and Injury Severity Score with an AUROC of 0.828. CONCLUSION: Glasgow Coma Scale score, pH, heart rate, age, Injury Severity Score, and 6-hour red blood cell transfusion requirement independently predict mortality in massively transfused trauma patients. Models incorporating these data have only a modest ability to predict mortality and should not be used to justify withholding massive transfusion in individual cases.


Asunto(s)
Transfusión Sanguínea , Hemorragia/mortalidad , Hemorragia/terapia , Heridas y Lesiones/mortalidad , Heridas y Lesiones/terapia , Adulto , Femenino , Hemorragia/etiología , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Curva ROC , Estudios Retrospectivos , Factores de Riesgo , Tasa de Supervivencia , Índices de Gravedad del Trauma , Heridas y Lesiones/complicaciones , Adulto Joven
14.
J Trauma ; 71(2 Suppl 3): S375-9, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21814107

RESUMEN

BACKGROUND: Recent data suggest that patients undergoing massive transfusion have lower mortality rates when ratios of plasma and platelets to red blood cells (RBCs) of ≥ 1:2 are used. This has not been examined independently in women and men. A gender dichotomy in outcome after severe injury is known to exist. This study examined gender-related differences in mortality after high product ratio massive transfusion. METHODS: A retrospective study was conducted using a database containing massively transfused trauma patients from 23 Level I trauma centers. Baseline demographic, physiologic, and biochemical data were obtained. Univariate and logistic regression analyses were performed. Adjusted mortality in patients receiving high (≥ 1:2) or low (<1:2) ratios of plasma or platelets to RBCs was compared in women and men independently. RESULTS: Seven hundred four patients were analyzed. In males, mortality was lower for patients receiving a high plasma:RBC ratio at 24 hours (20.6% vs. 33.0% for low ratio, p = 0.005) and at 30 days (34.9% vs. 42.8%, p = 0.032). Males receiving a high platelet:RBC ratio also had lower 24-hour mortality (17.6% vs. 31.5%, p = 0.004) and 30-day mortality (32.1% vs. 42.2%, p = 0.045). Females receiving high ratios of plasma or platelets to RBCs had no improvement in 24-hour mortality (p = 0.119 and 0.329, respectively) or 30-day mortality (p = 0.199 and 0.911, respectively). Use of high product ratio transfusions did not affect 24-hour RBC requirements in males or females. CONCLUSION: Use of high plasma:RBC or platelet:RBC ratios in massive transfusion may benefit men more than women. This may be due to gender-related differences in coagulability. Further study is needed to determine whether separate protocols for women and men should be established.


Asunto(s)
Transfusión Sanguínea , Hemorragia/mortalidad , Hemorragia/terapia , Heridas y Lesiones/mortalidad , Heridas y Lesiones/terapia , Adulto , Recuento de Eritrocitos , Femenino , Hemorragia/sangre , Humanos , Masculino , Persona de Mediana Edad , Recuento de Plaquetas , Estudios Retrospectivos , Factores Sexuales , Tasa de Supervivencia , Centros Traumatológicos , Heridas y Lesiones/sangre , Adulto Joven
15.
J Trauma ; 71(2 Suppl 3): S384-8, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21814109

RESUMEN

BACKGROUND: The Injury Severity Score (ISS) is widely used as a method for rating severity of injury. The ISS is the sum of the squares of the three worst Abbreviated Injury Scale (AIS) values from three body regions. Patients with penetrating injuries tend to have higher mortality rates for a given ISS than patients with blunt injuries. This is thought to be secondary to the increased prevalence of multiple severe injuries in the same body region in patients with penetrating injuries, which the ISS does not account for. We hypothesized that the mechanism-based difference in mortality could be attributed to certain ISS ranges and specific AIS values by body region. METHODS: Outcome and injury scoring data were obtained from transfused patients admitted to 23 Level I trauma centers. ISS values were grouped into categories, and a logistic regression model was created. Mortality for each ISS category was determined and compared with the ISS 1 to 15 group. An interaction term was added to evaluate the effect of mechanism. Additional logistic regression models were created to examine each AIS category individually. RESULTS: There were 2,292 patients in the cohort. An overall interaction between ISS and mechanism was observed (p = 0.049). Mortality rates between blunt and penetrating patients with an ISS between 25 and 40 were significantly different (23.6 vs. 36.1%; p = 0.022). Within this range, the magnitude of the difference in mortality was far higher for penetrating patients with head injuries (75% vs. 37% for blunt) than truncal injuries (26% vs. 17% for blunt). Penetrating trauma patients with an AIS head of 4 or 5, AIS abdomen of 3, or AIS extremity of 3 all had adjusted mortality rates higher than blunt trauma patients with those values. CONCLUSION: Significant differences in mortality between blunt and penetrating trauma patients exist at certain ISS and AIS category values. The mortality difference is greatest for head injured patients.


Asunto(s)
Traumatismo Múltiple/diagnóstico , Traumatismo Múltiple/mortalidad , Heridas Penetrantes/diagnóstico , Heridas Penetrantes/mortalidad , Escala Resumida de Traumatismos , Adulto , Anciano , Estudios de Cohortes , Femenino , Humanos , Puntaje de Gravedad del Traumatismo , Modelos Logísticos , Masculino , Persona de Mediana Edad , Traumatismo Múltiple/complicaciones , Valor Predictivo de las Pruebas , Tasa de Supervivencia , Centros Traumatológicos , Heridas Penetrantes/complicaciones , Adulto Joven
16.
J Trauma ; 71(2 Suppl 3): S389-93, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21814110

RESUMEN

BACKGROUND: Significant differences in outcomes have been demonstrated between Level I trauma centers. Usually these differences are ascribed to regional or administrative differences, although the influence of variation in clinical practice is rarely considered. This study was undertaken to determine whether differences in early mortality of patients receiving a massive transfusion (MT, ≥ 10 units pf RBCs within 24 hours of admission) persist after adjustment for patient and transfusion practice differences. We hypothesized differences among centers in 24-hour mortality could predominantly be accounted for by differences in transfusion practices as well as patient characteristics. METHODS: Data were retrospectively collected over a 1-year period from 15 Level I centers on patients receiving an MT. A purposeful variable selection strategy was used to build the final multivariable logistic model to assess differences between centers in 24-hour mortality. Adjusted odds ratios for each center were calculated. RESULTS: : There were 550 patients evaluated, but only 443 patients had complete data for the set of variables included in the final model. Unadjusted mortality varied considerably across centers, ranging from 10% to 75%. Multivariable logistic regression identified injury severity score (ISS), abbreviated injury scale (AIS) of the chest, admission base deficit, admission heart rate, and total units of RBC transfused, as well as ratios of plasma:RBC and platelet:RBC to be associated with 24-hour mortality. After adjusting for severity of injury and transfusion, treatment variables between center differences were no longer significant. CONCLUSIONS: In the defined population of patients receiving an MT, between-center differences in 24-hour mortality may be accounted for by severity of injury as well as transfusion practices.


Asunto(s)
Transfusión Sanguínea , Hemorragia/mortalidad , Hemorragia/terapia , Centros Traumatológicos , Heridas y Lesiones/mortalidad , Heridas y Lesiones/terapia , Adulto , Anciano , Femenino , Mortalidad Hospitalaria , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Índices de Gravedad del Trauma , Resultado del Tratamiento , Adulto Joven
17.
J Trauma ; 71(2 Suppl 3): S318-28, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21814099

RESUMEN

BACKGROUND: Several recent military and civilian trauma studies demonstrate that improved outcomes are associated with early and increased use of plasma-based resuscitation strategies. However, outcomes associated with platelet transfusions are poorly characterized. We hypothesized that increased platelet:red blood cells (RBC) ratios would decrease hemorrhagic death and improve survival after massive transfusion (MT). METHODS: A transfusion database of patients transported from the scene to 22 Level I Trauma Centers over 12 months in 2005 to 2006 was reviewed. MT was defined as receiving ≥ 10 RBC units within 24 hours of admission. To mitigate survival bias, 25 patients who died within 60 minutes of arrival were excluded from analysis. Six random donor platelet units were considered equal to a single apheresis platelet unit. Admission and outcome data associated with the low (>1:20), medium (1:2), and high (1:1) platelet:RBC ratios were examined. These groups were based on the median value of the tertiles for the ratio of platelets:RBC units. RESULTS: Two thousand three hundred twelve patients received at least one unit of blood and 643 received an MT. Admission vital signs, INR, temperature, pH, Glasgow Coma Scale, Injury Severity Score, and age were similar between platelet ratio groups. The average admission platelet counts were lower in the patients who received the high platelet:RBC ratio versus the low ratio (192 vs. 216, p = 0.03). Patients who received MT were severely injured, with a mean (± standard deviation) Injury Severity Score of 33 ± 16 and received 22 ± 15 RBCs and 11 ± 14 platelets within 24 hours of injury. Increased platelet ratios were associated with improved survival at 24 hours and 30 days (p < 0.001 for both). Truncal hemorrhage as a cause of death was decreased (low: 67%, medium: 60%, high: 47%, p = 0.04). Multiple organ failure mortality was increased (low: 7%, medium: 16%, high: 27%, p = 0.003), but overall 30-day survival was improved (low: 52%, medium: 57%, high: 70%) in the high ratio group (medium vs. high: p = 0.008; low vs. high: p = 0.007). CONCLUSION: Similar to recently published military data, transfusion of platelet:RBC ratios of 1:1 was associated with improved early and late survival, decreased hemorrhagic death and a concomitant increase in multiple organ failure-related mortality. Based on this large retrospective study, increased and early use of platelets may be justified, pending the results of prospective randomized transfusion data.


Asunto(s)
Transfusión Sanguínea , Hemorragia/sangre , Hemorragia/terapia , Heridas y Lesiones/sangre , Heridas y Lesiones/mortalidad , Adulto , Servicio de Urgencia en Hospital , Recuento de Eritrocitos , Femenino , Hemorragia/mortalidad , Humanos , Masculino , Persona de Mediana Edad , Recuento de Plaquetas , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Tasa de Supervivencia , Resultado del Tratamiento , Heridas y Lesiones/terapia , Adulto Joven
18.
Sci Rep ; 11(1): 10072, 2021 05 12.
Artículo en Inglés | MEDLINE | ID: mdl-33980902

RESUMEN

Twenty-four palaeogenomes from Mokrin, a major Early Bronze Age necropolis in southeastern Europe, were sequenced to analyse kinship between individuals and to better understand prehistoric social organization. 15 investigated individuals were involved in genetic relationships of varying degrees. The Mokrin sample resembles a genetically unstructured population, suggesting that the community's social hierarchies were not accompanied by strict marriage barriers. We find evidence for female exogamy but no indications for strict patrilocality. Individual status differences at Mokrin, as indicated by grave goods, support the inference that females could inherit status, but could not transmit status to all their sons. We further show that sons had the possibility to acquire status during their lifetimes, but not necessarily to inherit it. Taken together, these findings suggest that Southeastern Europe in the Early Bronze Age had a significantly different family and social structure than Late Neolithic and Early Bronze Age societies of Central Europe.


Asunto(s)
Relaciones Familiares , Genética de Población , Genoma Humano , Herencia , Distancia Psicológica , Clase Social/historia , Adolescente , Adulto , Niño , Preescolar , Femenino , Estudios de Seguimiento , Historia Antigua , Migración Humana , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Tasa de Supervivencia , Adulto Joven
19.
J Exp Med ; 193(3): 353-64, 2001 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-11157055

RESUMEN

Invasive Salmonella induces macrophage apoptosis via the activation of caspase-1 by the bacterial protein SipB. Here we show that infection of macrophages with Salmonella causes the activation and degradation of Raf-1, an important intermediate in macrophage proliferation and activation. Raf-1 degradation is SipB- and caspase-1-dependent, and is prevented by proteasome inhibitors. To study the functional significance of Raf-1 in this process, the c-raf-1 gene was inactivated by Cre-loxP-mediated recombination in vivo. Macrophages lacking c-raf-1 are hypersensitive towards pathogen-induced apoptosis. Surprisingly, activation of the antiapoptotic mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) and nuclear factor kappaB pathways is normal in Raf-1-deficient macrophages, and mitochondrial fragility is not increased. Instead, pathogen-mediated activation of caspase-1 is enhanced selectively, implying that Raf-1 antagonizes stimulus-induced caspase-1 activation and apoptosis.


Asunto(s)
Apoptosis , Macrófagos/citología , Proteínas Proto-Oncogénicas c-raf/fisiología , Salmonella typhimurium/fisiología , Animales , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Células de la Médula Ósea/citología , Células de la Médula Ósea/efectos de los fármacos , Células de la Médula Ósea/enzimología , Caspasa 1/metabolismo , Células Cultivadas , Activación Enzimática , Leupeptinas/farmacología , Macrófagos/efectos de los fármacos , Macrófagos/enzimología , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Ratones , Ratones Endogámicos C57BL , Mitocondrias/metabolismo , Proteínas Quinasas Activadas por Mitógenos/metabolismo , FN-kappa B/metabolismo , Inhibidores de Proteasas/farmacología , Proteínas Proto-Oncogénicas c-raf/metabolismo
20.
Bioinformatics ; 24(18): 2096-7, 2008 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-18689808

RESUMEN

SUMMARY: BioJava is a mature open-source project that provides a framework for processing of biological data. BioJava contains powerful analysis and statistical routines, tools for parsing common file formats and packages for manipulating sequences and 3D structures. It enables rapid bioinformatics application development in the Java programming language. AVAILABILITY: BioJava is an open-source project distributed under the Lesser GPL (LGPL). BioJava can be downloaded from the BioJava website (http://www.biojava.org). BioJava requires Java 1.5 or higher. All queries should be directed to the BioJava mailing lists. Details are available at http://biojava.org/wiki/BioJava:MailingLists.


Asunto(s)
Biología Computacional/métodos , Lenguajes de Programación , Conformación de Ácido Nucleico , Conformación Proteica , Análisis de Secuencia
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA