Baja tasa de infarto cerebral, infarto de miocardio y muerte vascular con el diagnóstico y tratamiento etiológico rápido del ataque isquémico transitorio

Resumen: Introducción: El riesgo de infarto cerebral dentro de los primeros 90 días tras un ataque isquémico transitorio (AIT) se estima entre un 8-20%. Existe escaso consenso sobre cuál es la estrategia diagnóstica más eficaz. Nuestro objetivo fue evaluar del beneficio del estudio precoz con ecocardiografía transtorácica (ETT) y ultrasonografía carotídea y transcraneal (DTSA/TC) en los pacientes con AIT. Métodos: Evaluamos de forma prospectiva todos los pacientes con AIT atendidos en urgencias durante 24 meses. Recogimos variables demográficas, factores de riesgo vascular y escala ABCD2. La etiología del AIT fue clasificada según criterios TOAST. En todos los pacientes se realizó el estudio vascular precoz (< 72 h) con ETT y DTSA/TC. Los objetivos primarios fueron la recurrencia vascular cerebral, infarto de miocardio (IAM) o muerte vascular durante el primer año. Resultados: Evaluamos 92 pacientes con una edad media de 68,3 ± 13 años y el 61% fueron hombres. La media de la escala ABCD2 fue de 3 puntos (≥ 5 en un 30%). La distribución etiológica fue la siguiente: aterotrombótico de gran vaso 12%; cardioembólico 30%; pequeño vaso 10%; indeterminado 40% e inhabitual 8%. Los hallazgos de la ETT cambiaron el tratamiento en 6 pacientes (6,5%) con exploración física y ECG normal. Al año de seguimiento 3 pacientes (3,2%) sufrieron un infarto cerebral, uno (1%) un IAM y no detectamos ninguna muerte vascular. Conclusiones: El estudio etiológico precoz en los pacientes con AIT y la detección de pacientes con cardiopatía silente puede haber contribuido a la baja tasa de recurrencia vascular. Abstract: Introduction: The 90-day risk of cerebral infarction in patients with transient ischaemic attack (TIA) is estimated at between 8% and 20%. There is little consensus as to which diagnostic strategy is most effective. This study evaluates the benefits of early transthoracic echocardiography (TTE) with carotid and transcranial Doppler ultrasound in patients with TIA. Methods: Prospective study of patients with TIA in an emergency department setting. Demographic data, vascular risk factors, and ABCD2 score were analysed. TIA aetiology was classified according to TOAST criteria. All patients underwent early vascular studies (< 72 hours), including TTE, carotid ultrasound, and transcranial Doppler. Primary endpoints were recurrence of stroke or TIA, myocardial infarction (MI), or vascular death during the first year. Results: We evaluated 92 patients enrolled over 24 months. Mean age was 68.3 ± 13 years and 61% were male. The mean ABCD2 score was 3 points (≥ 5 in 30%). The distribution of TIA subtypes was as follows: 12% large-artery atherosclerosis; 30% cardioembolism; 10% small-vessel occlusion; 40% undetermined cause; and 8% rare causes. Findings from the early TTE led to a change in treatment strategy in 6 patients (6.5%) who displayed normal physical examination and ECG findings. At one year of follow-up, 3 patients had experienced stroke (3.2%) and 1 patient experienced MI (1%); no vascular deaths were identified. Conclusions: In our TIA patients, early vascular study and detecting patients with silent cardiomyopathy may have contributed to the low rate of vascular disease recurrence. Palabras clave: Infarto cerebral, Ataque isquémico transitorio, Ecocardiografía, Keywords: Stroke, Transient ischaemic attack, Echocardiograph

Rapid diagnosis and treatment of TIA results in low rates of stroke, myocardial infarction and vascular death

Introduction: The 90-day risk of cerebral infarction in patients with transient ischaemic attack (TIA) is estimated at between 8% and 20%. There is little consensus as to which diagnostic strategy is most effective. This study evaluates the benefits of early transthoracic echocardiography (TTE) with carotid and transcranial Doppler ultrasound in patients with TIA. Methods: Prospective study of patients with TIA in an emergency department setting. Demographic data, vascular risk factors, and ABCD2 score were analysed. TIA aetiology was classified according to TOAST criteria. All patients underwent early vascular studies (< 72 hours), including TTE, carotid ultrasound, and transcranial Doppler. Primary endpoints were recurrence of stroke or TIA, myocardial infarction (MI), or vascular death during the first year. Results: We evaluated 92 patients enrolled over 24 months. Mean age was 68.3 ± 13 years and 61% were male. The mean ABCD2 score was 3 points (≥5 in 30%). The distribution of TIA subtypes was as follows: 12% large-artery atherosclerosis; 30% cardioembolism; 10% small-vessel occlusion; 40% undetermined cause; and 8% rare causes. Findings from the early TTE led to a change in treatment strategy in 6 patients (6.5%) who displayed normal physical examination and ECG findings. At one year of follow-up, 3 patients had experienced stroke (3.2%) and 1 patient experienced MI (1%); no vascular deaths were identified. Conclusions: In our TIA patients, early vascular study and detecting patients with silent cardiomyopathy may have contributed to the low rate of vascular disease recurrence. Resumen: Introducción: El riesgo de infarto cerebral dentro de los primeros 90 días tras un ataque isquémico transitorio (AIT) se estima entre un 8-20%. Existe escaso consenso sobre cuál es la estrategia diagnóstica más eficaz. Nuestro objetivo fue evaluar del beneficio del estudio precoz con ecocardiografía transtorácica (ETT) y ultrasonografía carotídea y transcraneal (DTSA/TC) en los pacientes con AIT. Métodos: Evaluamos de forma prospectiva todos los pacientes con AIT atendidos en urgencias durante 24 meses. Recogimos variables demográficas, factores de riesgo vascular y escala ABCD2. La etiología del AIT fue clasificada según criterios TOAST. En todos los pacientes se realizó el estudio vascular precoz (< 72 h) con ETT y DTSA/TC. Los objetivos primarios fueron la recurrencia vascular cerebral, infarto de miocardio (IAM) o muerte vascular durante el primer año. Resultados: Evaluamos 92 pacientes con una edad media de 68,3 ± 13 años y el 61% fueron hombres. La media de la escala ABCD2 fue de 3 puntos (≥ 5 en un 30%). La distribución etiológica fue la siguiente: aterotrombótico de gran vaso 12%; cardioembólico 30%; pequeño vaso 10%; indeterminado 40% e inhabitual 8%. Los hallazgos de la ETT cambiaron el tratamiento en 6 pacientes (6,5%) con exploración física y ECG normal. Al año de seguimiento 3 pacientes (3,2%) sufrieron un infarto cerebral, uno (1%) un IAM y no detectamos ninguna muerte vascular. Conclusiones: El estudio etiológico precoz en los pacientes con AIT y la detección de pacientes con cardiopatía silente puede haber contribuido a la baja tasa de recurrencia vascular. Keywords: Stroke, Transient ischaemic attack, Echocardiography, Palabras clave: Infarto cerebral, Ataque isquémico transitorio, Ecocardiografí

Prevalencia y factores de riesgo asociados a las enfermedades de transmisión sexual en bovinos de la provincia de La Pampa, Argentina

La tricomonosis bovina (TB) y campylobacteriosis genital bovina (CGB) son enfermedades de transmisión sexual (ETS) que causan muerte embrionaria temprana, infertilidad transitoria y abortos, impactando en el rendimiento reproductivo de los rodeos. El objetivo del presente estudio fue estimar la prevalencia general y por zonas fitogeográficas (Z1: Este pampeana, Z2: Monte central Z3: Monte occidental), así como los factores de riesgo asociados a ambas enfermedades en la provincia de La Pampa, Argentina. Se realizó un estudio transversal entre enero y diciembre del 2006 que abarcó a 4018 propietarios de rodeos con un stock de 684116 vacas y 33969 toros (54% y 51,5% del stock provincial, respectivamente). Se detectaron 622 (15,5%) rodeos con al menos 1 toro positivo a TB y/o CGB. Las prevalencias halladas fueron de 2,15% (Z1:1,62%; Z2:1,90%; Z3:4,61%) y 2,36% (Z1:2,08%; Z2: 2,28%; Z3: 3,51%) para TB y CGB, respectivamente. Los factores de riesgo asociados a la presencia de ETS fueron: traspaso de animales vecinos al establecimiento (Odds Ratio – OR = 1,8; Intervalo de Confianza-IC: 1,5-2,2) realización de servicio continuo (OR=1,3; IC: 1,1-1,6), productores que no realizan el tacto rectal (OR=1,2; IC: 1,0-1,5) y alta relación vaca/toro (χ.=35,1, p=<0,0001). Asimismo, las ETS se relacionaron con presencia de abortos (OR=1,3; IC: 1,0-1,7) y bajo porcentaje de preñez (OR=1,8; IC: 1,3-2,6). Este estudio provee información de interés para ser utilizada en los planes de control y erradicación en áreas en donde las ETS son de carácter endémico

Stay with the flow: How macroinvertebrate communities recover during the rewetting phase in Alpine streams affected by an exceptional drought

Droughts are affecting an increasing number of lotic ecosystems worldwide due to the combined effects of climatic and anthropogenic pressures. Unlike naturally intermittent rivers, where the drying phase is a part of the annual flow regime, water scarcity in Alpine rivers represents a relatively recent phenomenon and, therefore, a major threat for the biodiversity of these lotic ecosystems. However, Alpine stream community response to drought is still poorly investigated. Here, we assess the recovery of macroinvertebrates in two Alpine streams after a supraseasonal drought. As water returned, a total of 10 sampling sessions were carried out, and temporal patterns in diversity, density, and taxonomic composition of benthic communities, as well as in the percentage of functional feeding groups, were investigated. We found that the resistance of invertebrate communities in Alpine streams is generally low: drought markedly reduced the diversity and density of macroinvertebrates. Conversely, our results suggest that the passive dispersal by drift from the upstream river sections seems the most probable mechanism promoting the post-drought recovery. Nevertheless, this resilience ability appears to be stream specific and influenced by intrinsic stream characteristics, including the flow permanence and distance from the nearest upstream perennial reach. This work sheds light on the ecological consequences of droughts on macroinvertebrate communities. As flow intermittency in Alpine areas is expected to intensify under current global change scenarios, results of this study provide important information to predict changes in the taxonomic composition and diversity of macroinvertebrate communities

An experimental model for studying the biomechanics of embryonic tendon: Evidence that the development of mechanical properties depends on the actinomyosin machinery

Tendons attach muscles to bone and thereby transmit tensile forces during joint movement. However, a detailed understanding of the mechanisms that establish the mechanical properties of tendon has remained elusive because of the practical difficulties of studying tissue mechanics in vivo. Here we have performed a study of tendon-like constructs made by culturing embryonic tendon cells in fixed-length fibrin gels. The constructs display mechanical properties (toe–linear–fail stress–strain curve, stiffness, ultimate tensile strength, and failure strain) as well as collagen fibril volume fraction and extracellular matrix (ECM)/cell ratio that are statistically similar to those of embryonic chick metatarsal tendons. The development of mechanical properties during time in culture was abolished when the constructs were treated separately with Triton X-100 (to solubilise membranes), cytochalasin (to disassemble the actin cytoskeleton) and blebbistatin (a small molecule inhibitor of non-muscle myosin II). Importantly, these treatments had no effect on the mechanical properties of the constructs that existed prior to treatment. Live-cell imaging and (14)C-proline metabolic labeling showed that blebbistatin inhibited the contraction of the constructs without affecting cell viability, procollagen synthesis, or conversion of procollagen to collagen. In conclusion, the mechanical properties per se of the tendon constructs are attributable to the ECM generated by the cells but the improvement of mechanical properties during time in culture was dependent on non-muscle myosin II-derived forces