Combining biogeographical approaches to advance invasion ecology and methodology

Understanding the causes of plant invasions requires that parallel field studies are conducted in the native and introduced ranges to elucidate how biogeographical shifts alter the individual performance, population success and community-level impacts of invading plants. Three primary methods deployed in in situ biogeographical studies are directed surveys, where researchers seek out populations of target species, randomized surveys and field experiments. Despite the importance of these approaches for advancing biogeographical research, their relative merits have not been evaluated. We concurrently deployed directed surveys, randomized surveys and in situ field experiments for studying six grassland plant species in the native and introduced ranges. Metrics included plant size, fecundity, recruitment, abundance and invader impact, as well as soil properties and root associations with putative fungal mutualists and pathogens. Consistent with key invasion hypotheses, Bromus tectorum experienced increased size and fecundity in the introduced range linked to population increases and significant invader impacts, along with altered fungal associations. However, performance differences did not predict population increases and invader impacts across species. A notable finding was that disturbance facilitated greater recruitment in the introduced range for most species, thereby playing a crucial, though underappreciated, role in driving invader success. Directed surveys consistently generated information on plant performance and fungal associations. However, soil sampling suggested that directed surveys may have been biased towards disturbed conditions for half the species. Randomized surveys generated robust data for population comparisons and impact, but generally failed to produce performance metrics for species that were uncommon or flowered outside the peak sampling window. Field experiments controlled for bias and confounding factors and provided rare information on recruitment and disturbance effects, but poor recruitment in the native range and ethical constraints on growing invaders in the introduced range hindered comparisons of performance and plant–fungal interactions. Synthesis. Each method had strengths and weaknesses. However, when combined they provided complementary information to paint the most complete biogeographical picture to date for several introduced plants. We propose a hybrid approach to optimize biogeographical studies.Fil: Pearson, Dean. University of Montana; Estados Unidos. United States Forest Service. Rocky Mountain Research Station; ArgentinaFil: Eren, Ozkan. Adnan Menderes Universitesi; TurquíaFil: Ortega, Yvette K.. United States Forest Service. Rocky Mountain Research Station; ArgentinaFil: Hierro, Jose Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; ArgentinaFil: Karakuş, Birsen. Adnan Menderes Universitesi; TurquíaFil: Kala, Sascha. University of Montana; Estados UnidosFil: Bullington, Lorinda. Mpg Ranch; Estados UnidosFil: Lekberg, Ylva. University of Montana; Estados Unidos. Mpg Ranch; Estados Unido

Mitochondrial fusion is a therapeutic vulnerability of acute myeloid leukemia

Mitochondrial metabolism recently emerged as a critical dependency in acute myeloid leukemia (AML). The shape of mitochondria is tightly regulated by dynamin GTPase proteins, which drive opposing fusion and fission forces to consistently adapt bioenergetics to the cellular context. Here, we showed that targeting mitochondrial fusion was a new vulnerability of AML cells, when assayed in patient-derived xenograft (PDX) models. Genetic depletion of mitofusin 2 (MFN2) or optic atrophy 1 (OPA1) or pharmacological inhibition of OPA1 (MYLS22) blocked mitochondrial fusion and had significant anti-leukemic activity, while having limited impact on normal hematopoietic cells ex vivo and in vivo. Mechanistically, inhibition of mitochondrial fusion disrupted mitochondrial respiration and reactive oxygen species production, leading to cell cycle arrest at the G$_{0}$/G$_{1}$ transition. These results nominate the inhibition of mitochondrial fusion as a promising therapeutic approach for AML

Atrioventricular thrombus in a 14-year-old patient: a case report

Right atrioventricular thrombus was diagnosed by echocardiography in a 14-year-old boy. Thrombus was reached through the right ventricle to the pulmonary artery and it was caused to tricuspit valve insufficiency. Surgical thrombectomy was performed and, he was treated with oral anticoagulation in postoperative period

A causal relationship between right paraduodenal hernia and superior mesenteric artery syndrome: a case report

<p>Abstract</p> <p>Introduction</p> <p>Cases of right paraduodenal hernia and superior mesenteric artery syndrome have been reported separately, but their occurrence in combination has not been reported.</p> <p>Case presentation</p> <p>A 46-year-old Japanese man who had never undergone laparotomy was admitted to our hospital due to an acute abdomen. An enhanced multidetector-row computed tomography scan of our patient showed a cluster of small intestines with ischemic change in his right lateral abdominal cavity. Emergency surgery was subsequently performed, and strangulation of the distal jejunum along with incidental right paraduodenal hernia was found. His necrotic ileum was resected, and the jejunum encapsulated by the sac was repaired manually without reduction.</p> <p>Three days after the operation, however, our patient developed vomiting. An upper gastrointestinal series revealed a straight line cut-off sign on the third portion of his duodenum. A second enhanced multidetector-row computed tomography scan showed that he had a lower aortomesenteric angle and a shorter aortomesenteric distance compared to his condition before his right paraduodenal hernia was surgically repaired. We strongly suspected that the right paraduodenal hernia repair may have induced superior mesenteric artery syndrome. On the 21st post-operative day, duodenojejunostomy was performed because conservative management had failed.</p> <p>Conclusions</p> <p>In this case, enhanced multidetector-row computed tomography, which permits reconstructed multiplanar imaging, helped us to visually identify these diseases easily. It is important to recognize that surgical repair of a right paraduodenal hernia may cause superior mesenteric artery syndrome.</p

Post-kidney transplantation external iliac artery stenosis due to vascular clamp: Report of a case

We report a case of right external iliac artery stenosis after kidney transplantation surgery caused by vascular clamp application injury. The patient presented with claudication of the ipsilateral lower limb and the lesion was diagnosed angiographically. The patient was treated with endovascular stent placement. © 2014, Sociedade Brasileira de Angiologia e Cirurgia Vascular. All rights reserved

Acute renal artery thrombosis after kidney transplantation

Early kidney transplant loss as a result of acute thrombosis of the renal artery remains a constant and devastating complication, with an incidence of 0.2-7.5%. While uncommon, arterial obstruction in the early postoperative period is a surgical emergency and must be ruled out if previously established diuresis ceases suddenly. Arterial thrombosis may occur as a result of injury to a diseased artery, problems with anastomoses, hypercoagulability or malpositioning of the allograft. In this study, we analyzed data on a group of 105 renal transplant recipients who presented with acute postoperative graft dysfunction between January 2006 and May 2012, to identify cases of acute renal artery thrombosis. We report on our experience of immediate re-transplantation following early kidney transplant thrombosis. Overall, two (1.9%) patients suffered early (within 48 hours of surgery) allograft renal artery thrombosis. In both patients, transplantation had not been complicated by atherosclerotic lesions or other thrombophilic states and postoperative diuresis had been successfully achieved, but diuresis ceased abruptly during the early postoperative period. Emergent duplex ultrasound scans were performed and acute renal artery thrombosis was detected in both patients. The patients were operated immediately and retransplantation procedures were conducted. We have reported our experience of immediate retransplantation following early primary graft dysfunction due to renal artery thrombosis. In conclusion, close monitoring of postoperative diuresis and, if necessary, immediate retransplantation in this situation can prove to be a successful treatment for preventing graft loss. © 2014, Sociedade Brasileira de Angiologia e Cirurgia Vascular. All rights reserved