Incidencia de distintas frecuencias de corte en parámetros nutritivos de pasturas de alfalfa (Medicago sativa L.) de distinto grado de reposo invernal / Incidence of cutoff frequency in nutritional parameters of alfalfa (Medicago sativa L.) of different degrees of winter rest

Resumen El objetivo de este trabajo fue evaluar la calidad nutricional en 3 cultivares de alfalfa, pertenecientes a diferentes grupos de reposo invernal (GRI), sometidos a dos frecuencias de corte, durante un año del cultivo, fundamentado en que es abundante la información existente en estudios realizados en productividad, cobertura y persistencia, no así en la determinación de calidad de forraje sometidos a diferentes frecuencias de cortes y de GRI contrastantes. Se utilizaron tres cultivares (GR6-Verzy), (GR9-Mecha) y (GR10-Ruano). El diseño experimental fue de parcelas divididas con cuatro repeticiones. Se establecieron 2 tratamientos definidos por los intervalos entre cortes: T1: 25 días y T2: 35 días. Estos fueron precisados para las estaciones de primavera, verano y otoño. En invierno el intervalo fue de 45 y 55 días en T1 y T2, respectivamente. Las variables evaluadas fueron: porcentaje de materia seca (% MS), porcentaje de proteína bruta (% PB), porcentaje de fibra detergente neutro (% FDN) y porcentaje de fibra detergente ácido (% FDA). Se encontraron diferencias significativas para todas las variables nutricionales estudiadas, para ambos tratamientos. Se observó interacción entre cultivares y tratamiento para % PB. Los cultivares estudiados con diferentes GRI, no expresaron diferencias significativas en los parámetros de calidad evaluados para ninguna de las frecuencias de corte realizadas. La frecuencia de corte de 35 días arrojó los menores % PB y mayores % FDN y % FDA, por lo cual el forraje resulta para esta frecuencia de menor calidad, llevando a la disminución de la digestibilidad y aprovechamiento de la pastura para el ganado.

Abstract The objective of this work was to evaluate the nutritional quality in 3 cultivars of alfalfa, belonging to different winter dormancy (GRI), subjected to two cutting frequencies during one year of cultivation, based on the abundant information existing in studies carried out in productivity, coverage and persistence, not so in the determination of quality of forage subjected to different frequencies of cuts and contrasting GRI. Three cultivars (GR6-Verzy), (GR9-Mecha) and (GR10-Ruano) were tested. The experimental design was a complete split plot with four repetitions. Two treatments defined by the cutting intervals were established: T1: 25 days and T2: 35 days. These were specified for spring, summer and fall seasons. For winter the interval was 45 and 55 days in T1 and T2, respectively. The evaluated variables were: percentage of dry matter (% DM), percentage of crude protein (% PB), percentage of neutral detergent fiber (% FDN) and percentage of acid detergent fiber (% FDA). Significant differences were found for all the nutritional variables studied, for both treatment with p <0.05 with InfoStat program. Interaction between cultivars and treatment was observed for % PB. The 35 days cutoff frequency of yielded the lowest percentages of PB and the highest percentages of FDN and FDA. Hence the forage resulting from this frequency is of a lower quality, leading to decreased digestibility and lower performance of pasture for livestock.

Incidence of atrial fibrillation after percutaneous closure of patent foramen ovale and small atrial septal defects in patients presenting with cryptogenic stroke.

OBJECTIVE: The occurrence of atrial fibrillation after percutaneous closure of a patent foramen ovale for cryptogenic stroke has been reported in a variable percentage of patients. However, its precise incidence and mechanism are presently unclear and remain to be elucidated. DESIGN: Prospective follow-up study. PATIENTS: Ninety-two patients undergoing a percutaneous patent foramen ovale closure procedure (closure group) for cryptogenic stroke were compared with a similar group of 51 patients, who were medically treated. METHODS: A systematic arrhythmia follow-up protocol to assess the incidence of AF was performed including a 7-day event-loop recording at day 1, after 6 and 12 months in patients of the closure group and compared with those of the medically treated group. RESULTS: The incidence of AF was similar in both study groups during a follow-up of 12 months, including 7.6% (95% CI: 3.1-15.0%) in the closure and 7.8% (95% CI: 2.18-18.9%) in the medically treated group (P=1.0). The presence of a large patent foramen ovale was the only significant risk factor for the occurrence of AF as demonstrated by a multivariate Cox regression analysis (95% CI, 1.275-20.018; P=0.021). CONCLUSIONS: Our findings indicate that patients with cryptogenic stroke and patent foramen ovale have a rather high incidence of AF during a follow-up of 12 months. Atrial fibrillation occurred with a similar frequency whether the patent foramen ovale/atrial septal defect was successfully percutaneously closed or was medically managed. The presence of a large patent foramen ovale was the only significant predictor of AF occurrence during follow-up.

Penumbra system: a novel mechanical thrombectomy device for large-vessel occlusions in acute stroke.

BACKGROUND AND PURPOSE: Large IC artery occlusion is often resistant to recanalization. We present our initial experience with the PS. MATERIALS AND METHODS: Presenting with a severe acute ischemic stroke, the first 27 consecutive patients were considered for thromboaspiration therapy and retrospective data base analysis. All patients received standard thrombectomy treatment as monotherapy or in combination with thrombolysis or IC stent placement. The primary end point was revascularization of the target vessel to grade 2 or 3 on the TICI scale. Secondary end points were improvement of >4 points on the NIHSS score at discharge and favorable outcome, and improvement in overall mortality at 3 months and in sICH- and procedure-related adverse events. RESULTS: At baseline, the mean age was 66 +/- 14 years and the mean NIHSS score was 14 +/- 7. The anterior circulation was affected in 23 patients, and there were 4 basilar artery occlusions. Intracranial stent placement was performed in 4 patients. A recanalization to TICI 2 or 3 was achieved in 25 patients (93%). None of the patients developed sICH. At hospital discharge, 15 patients (56%) had an NIHSS improvement of >4 and 13 patients (48%) had an mRS score of <2 at 3 months. There was a significant correlation between complete vessel recanalization and favorable outcome. The all-cause mortality at 3 months was 11%. CONCLUSIONS: The PS showed a high potential for recanalization of acute thromboembolic occlusions of the large cerebral arteries. Complete recanalization was strongly correlated with good clinical outcome.

Evaluation of perfusion CT and TIBI grade in acute stroke for predicting thrombolysis benefit and clinical outcome.

OBJECTIVE: To evaluate the prognostic accuracy of combining perfusion CT (PCT) and thrombolysis in brain ischemia (TIBI) ultrasonographic grade in the triage of stroke patients who will benefit from thrombolysis and in predicting the clinical outcome. METHODS: We conducted a prospective study of all consecutive stroke patients admitted to our hospital from March 2003 to July 2007, presenting with signs of acute stroke within the therapeutic window, who had undergone either intravenous or combined intravenous and intra-arterial thrombolysis. All patients were evaluated by a complete stroke CT protocol, transcranial color-coded duplex sonographic monitoring, follow-up imaging (CT or MRI) and clinical outcome at 3 months, as assessed by the modified Rankin scale (mRS). RESULTS: A total of 34 patients were included with a mean NIHSS on admission of 14.2. This study revealed that PCT had 95% sensitivity and 71% specificity in the evaluation of therapy benefit as well as 75% sensitivity and 39% specificity in predicting clinical outcome. The extent of ischemic tissue according to PCT and TIBI grade were significantly correlated (p<0.05). Using the MTT-TTP approach was an alternative to the classical MTT-CBV approach for determining tissue at risk. The clinical outcome assessed by the mRS was considered favorable (mRS 0-2) in 16 patients and unfavorable (mRS>2) in 18 patients. CONCLUSION: PCT was the most accurate predictor of both thrombolytic therapy benefit and clinical outcome. The TIBI score was useful for determining whether or not to perform intravenous therapy alone or as a combined therapy.

BRAF and endocrine tumors: mutations are frequent in papillary thyroid carcinomas, rare in endocrine tumors of the gastrointestinal tract and not detected in other endocrine tumors.

The tumorigenesis of sporadic endocrine tumors is still not fully understood. Activating point mutations of the serine/threonine kinase gene BRAF located on 7q34 are found in a wide range of malignancies, with the highest frequency (66%) occurring in malignant melanomas. Melanomas are tumors of neural-crest-derived cells as are medullary thyroid carcinomas, pheochromocytomas and paragangliomas. BRAF has not been examined in endocrine tumors of the diffuse neuroendocrine system or of neural-crest-derived cells. We examined 130 endocrine tumors of the pancreas, parathyroid gland, adrenal medulla, paraganglia, lung and gastrointestinal tract as well as follicular and c-cell-derived thyroid tumors. We found a high rate of V559E mutations in papillary thyroid carcinomas (47%), one V599E mutation in a well-differentiated gastric endocrine carcinoma (malignant carcinoid), but no activating BRAF mutations in all other endocrine tumors examined. These results point towards different pathways in tumorigenesis of endocrine tumors of various localizations and only rare involvement of the MAP kinase (MAPK) pathway in a subset of malignant neuroendocrine tumors.