Efectos del anegamiento en invierno y verano sobre el crecimiento y la supervivencia de Lotus tenuis y Lotus corniculatus

Se estudió la tolerancia al anegamiento invernal y estival de Lotus tenuis y Lotus corniculatus. Ambas leguminosas son empleadas como forrajeras en campos bajos de la Pampa Deprimida (Buenos Aires, Argentina), donde L. tenuis aparece asociada a ambientes más inundables que L. corniculatus. Los tratamientos se realizaron eta macetas mantenidas en el exterior. Las plantas anegadas fueron mantenidas con un nivel de agua constante de 3 cm de altura sobre el nivel del suelo, mientras que las plantas testigos fueron regadas periódicamente. Los anegamientos se prolongaron hasta que alguna de las dos especies presentara 75% de clorosis (42 días en el tratamiento invernal y 17 días en el estival). El anegamiento invernal provocó eta ambas especies reducción del crecimiento aéreo, senescencia foliar, descomposición de raíces y formación de hipertrofias en los tallos, pero no se registró mortalidad. Tal reducción fue mayor en L. corniculatus, la cual presentó además un menor desarrollo de hipertrofias caulinares. Luego del período de anegamiento invernal, las plantas de L. tenuis presentaron una recuperación más rápida de biomasa que las de L. corniculatus. El anegamiento de verano provocó severa senescencia caulinar y foliar, y no se observaron hipertrofias. Finalizado el mismo, murieron el 100% de las plantas de L. corniculatus y el 50% de las de L. tenuis. Las plantas de L. tenuis que sobrevivieron se recuperaron lentamente y los nuevos tallos se desarrollaron a partir de la corona. La mayor tolerancia al anegamiento de L. tenuis respecto a L. corniculatus resulta coherente cota la segregación espacial de ambas especies registrada en estudios de campo.Tolerance to winter and summer waterlogging was expermentally studied in Lotus tenuis and Lotus corniculatus. Both legumes constitute an important forage resouce in the Flooding Pampa (Buenos Aires, Argentina), where L. tenuis occupies environments more exposed to flooding than L. corniculatus. Plants were cultivated individually in pots kept outdoors. Flooded plants were kept with a constant 3 cm water level above the soil surface, while controls were periodically watered. Plants were kept flooded until 75% of clorosis appeared on either species (42 days in the winter treatment and 17 days in the summer treatment). The winter treatment caused a decrease in aerial growth, leaf senescence, partial root decomposition and the formation of shoot hypertrophies, but no mortality. L. corniculatus was the most negatively affected species. Shoot hypertrophies were more abundant in L. tenuis. Weight recuperation after the winter waterlogging period was more rapid in L. tenuis than in L. corniculatus. The summer treatment caused high shot senescence in both species and no hypertrophy. After the waterlogging period, 50% of L. tenuis and 100% of L. corniculatus plants died. Regrowth of surviving L. tenuis plants was slow. The higher tolerance of L. tenuis to waterlogging agrees with the habitat segregation of both species observed infield studies

Efectos del anegamiento sobre el poder germinativo de las semillas de Lotus tenuis y Lotus corniculatus. Implicancias para su propagación diferencial en la Depresión del Salado (Buenos Aires, Argentina)

Lotus tenuis (L. t.) y Lotus corniculatus (L. c.) fueron introducidas como forrajeras en la Pampa Deprimida hace unos cincuenta años. Mientras que L. t. se ha difundido naturalmente en los campos bajos anegables de la región, L. c. no ha experimentado la misma expansión. En el presente trabajo se estudió la tolerancia al anegamiento de semillas de ambas especies en procura de explicar dicha distribución. Los experimentos de anegamiento se realizaron en recipientes que permanecieron en condiciones controladas de temperatura y luz. Las semillas estuvieron anegadas durante siete semanas y se realizaron muestreos a intervalos crecientes de tiempo. El poder germinativo (P. G., medida de la tolerancia al anegamiento), disminuyó en ambas especies al aumentar el tiempo de anegamiento, pero lo hizo en forma más acentuada en L. c. que en L. t.. La fracción de semillas blandas perdió antes el P. G. en L. c. que en L. t.. Con 49 días de anegamiento las semillas que conservaron el P. G. fueron las duras, las cuales se hallaban en mayor proporción en L. t. (aproximadamente 50% en L. t. y 6% en L. c., para semillas de 5 meses de edad). La capacidad de las semillas de L. t. de tolerar períodos prolongados de anegamiento jugaría un papel determinante en la expansión de la especie en los campos sujetos a inundaciones periódicas.Lotus tenuis (L. t.) and Lotus corniculatus (L. c.) were introduced as forage plants in the Flooding Pampa around 50 years ago. While L. t. has naturally colonized the frequently flooded habitats. L.c. has not shown the same expansion. In this paper we studied the tolerance to flooding of seeds of both species. The seeds were flooded during 7 weeks, in controlled conditions of temperature and light, and samples were taken at increasing time intervals. Germinative percentage (G. P.) of the seeds was taken as a measure of tolerance to flooding and it was found that although G. P. decreased with flooding time in both species, the soft seeds of L. c. lost viability earlier than those of L.t. With 49 days of flooding, hard seeds were the only ones that maintained the G.P. and were more frequent in L. t.. (aproximately 50% in L. t. and 6% in L. c, in 5 month old seeds). These characteristics probably play an important role in the capacity of L. t. of colonizing habitats that are periodically flooded

On improvement in ejection fraction with iron chelation in thalassemia major and the risk of future heart failure

<p>Abstract</p> <p>Background</p> <p>Trials of iron chelator regimens have increased the treatment options for cardiac siderosis in beta-thalassemia major (TM) patients. Treatment effects with improved left ventricular (LV) ejection fraction (EF) have been observed in patients without overt heart failure, but it is unclear whether these changes are clinically meaningful.</p> <p>Methods</p> <p>This retrospective study of a UK database of TM patients modelled the change in EF between serial scans measured by cardiovascular magnetic resonance (CMR) to the relative risk (RR) of future development of heart failure over 1 year. Patients were divided into 2 strata by baseline LVEF of 56-62% (below normal for TM) and 63-70% (lower half of the normal range for TM).</p> <p>Results</p> <p>A total of 315 patients with 754 CMR scans were analyzed. A 1% absolute increase in EF from baseline was associated with a statistically significant reduction in the risk of future development of heart failure for both the lower EF stratum (EF 56-62%, RR 0.818, p < 0.001) and the higher EF stratum (EF 63-70%, RR 0.893 p = 0.001).</p> <p>Conclusion</p> <p>These data show that during treatment with iron chelators for cardiac siderosis, small increases in LVEF in TM patients are associated with a significantly reduced risk of the development of heart failure. Thus the iron chelator induced improvements in LVEF of 2.6% to 3.1% that have been observed in randomized controlled trials, are associated with risk reductions of 25.5% to 46.4% for the development of heart failure over 12 months, which is clinically meaningful. In cardiac iron overload, heart mitochondrial dysfunction and its relief by iron chelation may underlie the changes in LV function.</p

Unrecognized Non-Q-Wave Myocardial Infarction: Prevalence and Prognostic Significance in Patients with Suspected Coronary Disease

Using delayed-enhancement cardiovascular magnetic resonance, Han Kim and colleagues show that in patients with suspected coronary disease the prevalence of unrecognized myocardial infarction without Q-waves is more than 3-fold higher than that with Q-waves and predicts subsequent mortality

Body surface area and baseline blood pressure predict subclinical anthracycline cardiotoxicity in women treated for early breast cancer.

BACKGROUND AND AIMS: Anthracyclines are highly effective chemotherapeutic agents which may cause long-term cardiac damage (chronic anthracycline cardiotoxicity) and heart failure. The pathogenesis of anthracycline cardiotoxicity remains incompletely understood and individual susceptibility difficult to predict. We sought clinical features which might contribute to improved risk assessment. METHODS: Subjects were women with early breast cancer, free of pre-existing cardiac disease. Left ventricular ejection fraction was measured using cardiovascular magnetic resonance before and >12 months after anthracycline-based chemotherapy (>3 months post-Trastuzumab). Variables associated with subclinical cardiotoxicity (defined as a fall in left ventricular ejection fraction of ≥5%) were identified by logistic regression. RESULTS: One hundred and sixty-five women (mean age 48.3 years at enrollment) completed the study 21.7 months [IQR 18.0-26.8] after starting chemotherapy. All received anthracyclines (98.8% epirubicin, cumulative dose 400 [300-450] mg/m2); 18% Trastuzumab. Baseline blood pressure was elevated (≥140/90mmHg, mean 147.3/86.1mmHg) in 18 subjects. Thirty-four subjects (20.7%) were identified with subclinical cardiotoxicity, independent predictors of which were the number of anthracycline cycles (odds ratio, OR 1.64 [1.17-2.30] per cycle), blood pressure ≥140/90mmHg (OR 5.36 [1.73-17.61]), body surface area (OR 2.08 [1.36-3.20] per standard deviation (0.16m2) increase), and Trastuzumab therapy (OR 3.35 [1.18-9.51]). The resultant predictive-model had an area under the receiver operating characteristics curve of 0.78 [0.70-0.86]. CONCLUSIONS: We found subclinical cardiotoxicity to be common even within this low risk cohort. Risk of cardiotoxicity was associated with modestly elevated baseline blood pressure-indicating that close attention should be paid to blood pressure in patients considered for anthracycline based chemotherapy. The association with higher body surface area suggests that indexing of anthracycline doses to surface area may not be appropriate for all, and points to the need for additional research in this area

Human resources: the Cinderella of health sector reform in Latin America

Human resources are the most important assets of any health system, and health workforce problems have for decades limited the efficiency and quality of Latin America health systems. World Bank-led reforms aimed at increasing equity, efficiency, quality of care and user satisfaction did not attempt to resolve the human resources problems that had been identified in multiple health sector assessments. However, the two most important reform policies – decentralization and privatization – have had a negative impact on the conditions of employment and prompted opposition from organized professionals and unions. In several countries of the region, the workforce became the most important obstacle to successful reform. This article is based on fieldwork and a review of the literature. It discusses the reasons that led health workers to oppose reform; the institutional and legal constraints to implementing reform as originally designed; the mismatch between the types of personnel needed for reform and the availability of professionals; the deficiencies of the reform implementation process; and the regulatory weaknesses of the region. The discussion presents workforce strategies that the reforms could have included to achieve the intended goals, and the need to take into account the values and political realities of the countries. The authors suggest that autochthonous solutions are more likely to succeed than solutions imported from the outside

Review of journal of cardiovascular magnetic resonance 2010

There were 75 articles published in the Journal of Cardiovascular Magnetic Resonance (JCMR) in 2010, which is a 34% increase in the number of articles since 2009. The quality of the submissions continues to increase, and the editors were delighted with the recent announcement of the JCMR Impact Factor of 4.33 which showed a 90% increase since last year. Our acceptance rate is approximately 30%, but has been falling as the number of articles being submitted has been increasing. In accordance with Open-Access publishing, the JCMR articles go on-line as they are accepted with no collating of the articles into sections or special thematic issues. Last year for the first time, the Editors summarized the papers for the readership into broad areas of interest or theme, which we felt would be useful to practitioners of cardiovascular magnetic resonance (CMR) so that you could review areas of interest from the previous year in a single article in relation to each other and other recent JCMR articles [1]. This experiment proved very popular with a very high rate of downloading, and therefore we intend to continue this review annually. The papers are presented in themes and comparison is drawn with previously published JCMR papers to identify the continuity of thought and publication in the journal. We hope that you find the open-access system increases wider reading and citation of your papers, and that you will continue to send your quality manuscripts to JCMR for publication

Towards accurate and precise T1 and extracellular volume mapping in the myocardium: a guide to current pitfalls and their solutions

Mapping of the longitudinal relaxation time (T1) and extracellular volume (ECV) offers a means of identifying pathological changes in myocardial tissue, including diffuse changes that may be invisible to existing T1-weighted methods. This technique has recently shown strong clinical utility for pathologies such as Anderson- Fabry disease and amyloidosis and has generated clinical interest as a possible means of detecting small changes in diffuse fibrosis; however, scatter in T1 and ECV estimates offers challenges for detecting these changes, and bias limits comparisons between sites and vendors. There are several technical and physiological pitfalls that influence the accuracy (bias) and precision (repeatability) of T1 and ECV mapping methods. The goal of this review is to describe the most significant of these, and detail current solutions, in order to aid scientists and clinicians to maximise the utility of T1 mapping in their clinical or research setting. A detailed summary of technical and physiological factors, issues relating to contrast agents, and specific disease-related issues is provided, along with some considerations on the future directions of the field. Towards accurate and precise T1 and extracellular volume mapping in the myocardium: a guide to current pitfalls and their solutions. Available from: https://www.researchgate.net/publication/317548806_Towards_accurate_and_precise_T1_and_extracellular_volume_mapping_in_the_myocardium_a_guide_to_current_pitfalls_and_their_solutions [accessed Jun 13, 2017]

Current cardiac imaging techniques for detection of left ventricular mass

Estimation of left ventricular (LV) mass has both prognostic and therapeutic value independent of traditional risk factors. Unfortunately, LV mass evaluation has been underestimated in clinical practice. Assessment of LV mass can be performed by a number of imaging modalities. Despite inherent limitations, conventional echocardiography has fundamentally been established as most widely used diagnostic tool. 3-dimensional echocardiography (3DE) is now feasible, fast and accurate for LV mass evaluation. 3DE is also superior to conventional echocardiography in terms of LV mass assessment, especially in patients with abnormal LV geometry. Cardiovascular magnetic resonance (CMR) and cardiovascular computed tomography (CCT) are currently performed for LV mass assessment and also do not depend on cardiac geometry and display 3-dimensional data, as well. Therefore, CMR is being increasingly employed and is at the present standard of reference in the clinical setting. Although each method demonstrates advantages over another, there are also disadvantages to receive attention. Diagnostic accuracy of methods will also be increased with the introduction of more advanced systems. It is also likely that in the coming years new and more accurate diagnostic tests will become available. In particular, CMR and CCT have been intersecting hot topic between cardiology and radiology clinics. Thus, good communication and collaboration between two specialties is required for selection of an appropriate test