Predictors of recurrence of cancer-associated venous thromboembolism after discontinuation of anticoagulant therapy: a multicenter cohort study.

BACKGROUND: Data on recurrence after the end of anticoagulation for a first event of cancer-associated venous thromboembolism (VTE) are scarce. OBJECTIVES: Our aim was to assess predictors of VTE recurrence during a 1-year follow-up period. METHODS: This study is an analysis of RIETE, an international, multicenter, prospective cohort study of patients diagnosed with VTE. Patients had to have active cancer at the time of VTE and to have withdrawn from anticoagulation after 3 months of full treatment. Analyses were performed using Fine and Gray models, with death as a competing risk, and multiple imputation of missing data was performed by chained equations. RESULTS: Among 14 318 patients with cancer-associated VTE, 3414 had undergone time-limited anticoagulation for at least 3 months. The cumulative incidence function for recurrent VTE was 10.2% (95% CI, 9.1-11.5) at 1 year. Chronic kidney disease (a subhazard ratio [sHR] of 1.08 for 10-mL/min decrease in glomerular filtration rate; 95% CI, 1.02-1.14); cancer of the lung, brain, stomach, esophagus, liver, or ovary (sHR, 3.56; 95% CI, 1.07-11.80; compared with cancer of the oropharynx, larynx, or melanoma); cancer of the pancreas, the biliary tract, or of unknown origin (sHR, 6.86; 95% CI, 1.89-24.85); inferior vena cava filter (sHR, 3.16; 95% CI, 1.75-5.71); postthrombotic syndrome (sHR, 2.09; 95% CI, 1.06-4.15); and residual pulmonary thrombotic obstruction (sHR, 2.58; 95% CI, 1.38-4.82) were predictive of recurrence. Surgery during the 2 months before VTE was predictive of absence of recurrence (sHR, 0.60; 95% CI, 0.40-0.92). CONCLUSION: One year after anticoagulant cessation for cancer-associated VTE, approximately 10% of patients experienced recurrence. Discontinuing anticoagulant therapy seems safe, mainly in surgery-associated VTE.

Síndrome de Hamman y neumatosis epidural asociada / No disponible

No disponible

Using GPUs for the exact alignment of short-read genetic sequences by means of the Burrows-Wheeler transform.

General Purpose Graphic Processing Units (GPGPUs) constitute an inexpensive resource for computing-intensive applications that could exploit an intrinsic fine-grain parallelism. This paper presents the design and implementation in GPGPUs of an exact alignment tool for nucleotide sequences based on the Burrows-Wheeler Transform. We compare this algorithm with state-of-the-art implementations of the same algorithm over standard CPUs, and considering the same conditions in terms of I/O. Excluding disk transfers, the implementation of the algorithm in GPUs shows a speedup larger than 12, when compared to CPU execution. This implementation exploits the parallelism by concurrently searching different sequences on the same reference search tree, maximizing memory locality and ensuring a symmetric access to the data. The paper describes the behavior of the algorithm in GPU, showing a good scalability in the performance, only limited by the size of the GPU inner memory.

Characterization of events by aerosol mass size distributions.

Continuous measurements of particle mass size distributions were carried out in summer 2004 at an urban location in the western Mediterranean using an optical particle counter. In this work we propose a simple methodology to identify PM episodes and determine their influence on mass size distributions. During the study period three types of event produced a significant increase in TSP daily levels: Saharan dust intrusions, firework displays and strong winds, modifying size distributions in different ways. As well, a traffic-related mass size spectrum was obtained showing road dust particles injected into the atmosphere by vehicle-induced resuspension having mainly aerodynamic diameters between 5 and 15 microm. This was confirmed by principal component and conditional probability function analyses.

Effects of public health interventions on industrial emissions and ambient air in Cartagena, Spain.

BACKGROUND, AIM, AND SCOPE: Ten years of public health interventions on industrial emissions to clean air were monitored for the Mediterranean city of Cartagena. During the 1960s, a number of large chemical and non-ferrous metallurgical factories were established that significantly deteriorated the city's air quality. By the 1970s, the average annual air concentration of sulfur dioxide (SO2) ranged from 200 to 300 microg/m3 (standard conditions units). In 1979, the Spanish government implemented an industrial intervention plan to improve the performance of factories and industrial air pollution surveillance. Unplanned urban development led to residential housing being located adjacent to three major factories. Factory A produced lead, factory B processed zinc from ore concentrates, and factory C produced sulfuric acid and phosphates. This, in combination with the particular abrupt topography and frequent atmospheric thermal inversions, resulted in the worsening of air quality and heightening concern for public health. In 1990, the City Council authorized the immediate intervention at these factories to reduce or shut down production if ambient levels of SO2 or total suspended particles (TSP) exceeded a time-emission threshold in pre-established meteorological contexts. The aim of this research was to assess the appropriateness and effectiveness of the intervention plan implemented from 1992 to 2001 to abate industrial air pollution. MATERIALS AND METHODS: The maximum daily 1-h ambient air level of SO2, NO2, and TSP pollutants was selected from one of the three urban automatic stations, designed to monitor ambient air quality around industrial emissions sources. The day on which an intervention took place to reduce and/or interrupt industrial production by factory and pollutant was defined as a control day, and the day after an intervention as a post-control day. To assess the short-term intervention effect on air quality, an ecological time series design was applied, using regression analysis in generalized additive models, focusing on day-to-day variations of ambient air pollutants levels. Two indicators were estimated: (a) appropriateness, the ratio between mean levels of the pollutant for control days versus the other days, and (b) effectiveness, the ratio between mean levels of the pollutant for post-control days versus the other days. Ratios in regression analyses were adjusted for trend, seasonality, temperature, humidity and atmospheric pressure, calendar day, and special events as well as the other pollutants. RESULTS: A total of 702 control days were made on the factories' industrial production during the 10-year period. Fifteen reductions and five shutdown control days took place at factory A for ambient air SO2. At factory B, more controls were carried out for the SO2 pollutant in the years 1992-1993 and 1997. At factory C, the control days for SO2 decreased from 59 reductions and 14 shutdowns to a minimum from 1995 onwards, whereas the controls on TSP were more frequent, reaching a maximum of 99 reductions and 47 shutdowns in the last year. SO2 ambient air mean levels ranged from 456 to 699 microg/m(3) among factories on reduction control days and between 624 and 1,010 microg/m(3) on shutdown days. The TSP ambient air mean levels were 428 and 506 microg/m(3) on reduction and shutdown days, respectively. For all types of control days and factories, a mean ratio of 104% (95% confidence interval [CI] 88 to 121) in SO(2) levels was obtained and a mean ratio of 67% (95% CI 59 to 75) in TSP levels. Post-control days at all factories showed a mean ratio of -16% (95% CI -7 to -24) in SO(2) levels and a mean ratio of -13% (95% CI -7 to -19) in TSP levels. DISCUSSION: Interventions on industrial production based on the urban SO(2) and TSP ambient air levels were justified by the high concentrations detected. The best assessment of the interventions' effectiveness would have been to utilize the ambient air pollutant concentration readings from the entire time of the production shutdowns or reductions; however, the daily hourly maximum turned out to be a useful indicator because of meteorological factors influencing the diurnal concentration profile. A substantial number of interventions were carried out from 1 to 3 AM: , when vehicular traffic was minimum. On the other hand, atmospheric stability undergoes diurnal cycling in the autumn-winter period due to thermal inversion, which reaches maximum levels around daybreak. Therefore, this increases the ambient air levels and justified the interventions carried out at daybreak in spite of the traffic influence. CONCLUSIONS: All the interventions for SO(2) and TSP were carried out when the measured ambient air levels of pollutants were exceeded, which shows the appropriateness of the intervention program. This excess was greater when intervening on SO(2) than on the TSP levels. For both ambient air levels of SO(2) and TSP, significant drops in air pollution were achieved from all three factories following activity reductions. The production shutdown controls were very effective, because they returned excess levels, higher than in the reduction controls, to everyday mean values. RECOMMENDATIONS AND PERSPECTIVES: The Cartagena City observational system of intermittent control has proven to effectively reduce industrial emissions' impact on ambient air quality. This experienced model approach could serve well in highly polluted industrial settings. From a public health perspective, studies are needed to assess that the industrial interventions to control air pollution were related to healthier human populations. Legislation was needed to allow the public administration to take direct actions upon the polluting industries.

Proteínas C reactiva en artroplastía total de cadera / C-reactive protein in total hip arthroplasty

Se realizó un estudio clínico prospectivo en 100 artroplastías totales de cadera (ATC) primarias en 98 pacientes, a quienes se realizó ocho determinaciones de proteína C reactiva (PCR) sérica: una en el preoperatorio, y en el postoperatorio en los días primero, tercero, cuarto, quinto, y a las tres, cuatro y ocho semanas. La curva de la PCR presentó un comportamiento bifásico en 98 ATC sin complicaciones, con una evaluación máxima sobre los valores normales al tercero o cuarto día, un descenso acelerado hacia el quinto día, y un descenso lento posterios hacia valores normales. Hubo dos casos en los que la PCR aumentó al quinto día en pacientes que presentaron una neumonía y una infección superficial de la herida quirúrgica, respectivamente. En conclusión, la PCR puede ayudar a controlar la evolución normal de los pacientes sometidos a ATC. Las alteraciones de la curva normal pueden indicar una infección con repercusión sistémica

Contaminación de la cánula de aspiración en artroplastía total de cadera / Suction tip contamination in total hip arthroplasty

La infección periprotésica es una de las complicaciones más devastadoras de la artroplastía total de cadera. Un alto porcentaje de éstas se originan por contaminación intraoperatoria. Uno de los factores involucrados en esta contaminación sería la cánula de aspiración. Se realizó un estudio prospectivo para determinar la contaminación de las cánulas de aspiración en artroplastía total de cadera. Se estudiaron 60 pacientes sometidos a artroplastía total de cadera primaria por atrosis. Se utilizó aspiración continua con cánula desechable tipo Yankauer, la que se cultivó al cabo de una hora de cirugía. De las sesenta cánulas cultivadas, en 13 (21,6 por ciento) hubo desarrollo de bacterias, siendo la bacteria identificada con mayor frecuencia el estafilococo coagulasa negativo (76,9 por ciento). No existieron evidencias de complicaciones infecciosas en ninguno de los pacientes, tanto en el postoperatorio inmediato como alejado (8-24 meses). Concluimos que el uso prolongado de una cánula de aspiración puede ser una potencial fuente de contaminación en artroplastía total de cadera

Uso de antibióticos locales en el tratamiento de infecciones osteoarticulares / Use of local antibiotics in the treatment of osteo articular infections

La vancomicina cumple con los requisitos farmacológicos para ser agregado al cemento polimetilmetacrilato (PMMA). Este antibiótico es liberado del implante de cemento logrando elevados niveles en la zona operatoria por un período prolongado y con una efectiva acción antimicrobiana. En el período de junio 98 a mayo 99 fueron tratados 7 pacientes con una osteosíntesis infectada, 5 de ellas por staphylococcus aureus methicilina resistentes (SAMR), en quienes no se había logrado controlar la infección pese a múltiples cirugías previas y terapia antibiótica sistémica prolongada. El tratamiento consistió en un nuevo aseo quirúrgico complementado con un implante local de vacomicina en forma de perlas confeccionadas manualmente durante la cirugía. En 6 de los 7 pacientes con esta única intervención quirúrgica se logró controlar en forma definitiva la infección. La vancomicina tiene la ventaja de su disponibilidad en nuestro médio nacional así como la efectividad contra SAMR. Este implante de vancomicina al igual que en otras infecciones osteoarticulares siempre debe ser considerado como un arma terapéutica complementaria al aseo quirúrgico necesario para el tratamiento de estas infecciones

Diagnóstico y manejo de la artroplastía de cadera infectada / Diagnosis and management of infected hip artroplasty

La infección periprotésica, complicación de aproximadamente uno porciento de las artroplastías totales de cadera, entraña un elevado costo emocional y económico para el paciente y para los sistemas de salud respectivamente. En este artículo se revisan la fisiopatología de esta complicación y los recursos diagnósticos disponibles. Para su tratamiento se proponen dos alternativas: debridamiento con retención del implante y resección de la artroplastía ( en uno o dos tiempos). Se hace referencia al beneficio de antimicrobianos tópicos al momento de instalar la protésis articular para prevenir la infección

Emergencias infecciosas osteoarticulares en el niño / Osteoarticular infection emergencies in children

Las estructuras osteroarticulares del aparato locomotor pueden sufrir la invasión y posterior colonización de bacterias que llegan a ellas por diferentes vías. En general constituyen procesos graves que deben ser considerados con el carácter de una emergencia, ya que tienden a la destrucción anatómica de las estructuras comprometidas y a la diseminación tanto local como sistématica de la infección si su evolución natural no se detiene mediante un adecuado tratamiento médico-quirúrgico. El retardo en el diagnóstico y tratamiento aumentan las posibilidades de causar secuelas permanentes y devastadoras en el niño, alterando su patrón de vida, sus relaciones sociales y sus potencialidades en forma irreversible. Se analizará a continuación, en forma separada, la osteomielitis aguda y la artritis séptica