Dietary selenium affects intestinal development of Eimeria papillata in mice

Here, we investigated the effect of the trace element selenium (Se) on course and outcome of Eimeria-paplllata-induced coccidiosis in mice. Male mice were fed on Se-adequate (0.15 ppm), Se-deficient, and Se-high diets (1.0 ppm) for 6 weeks. Mice were orally infected with 1,000 oocysts. The prepatent period lasts for 3 days, but the course of infections varied. At Se-adequate diet, the maximum fecal output of oocysts amounted to 68,300 ooccysts/g feces on day 5 p.i.. However, fecal shedding of oocysts was accelerated in mice on Se-deficient diet and occurred already on day 4 p.i.. By contrast, maximal shedding is impaired in mice on high-Se diet, which takes place on day 5 p.i., but with a decreased output of only 7,300 oocysts/g feces. Light microscopy reveals that all developmental stages are affected: meronts, micro- and macrogamonts, and developing oocysts are increased in comparison with mice fed on selenium-adequate diet. At high Se, the number of parasitic stages in the jejunum is substantially higher than at Se-deficient diet. Se does not affect the number of jejunal Alcian blue-stained goblet cells. Se deficiency increased the number of apoptotic cells in the jejunum. Substantially increased histological injury scores reveal more injuries in jejunum tissue infected by E. papillata. Our data indicate that high dietary Se exerts potential anticoccidial activity. This may be taken advantage of in control measures towards Eimeriosis as a feed additive, potentially alleviating the need for concomitantly utilized anti-coccidial drugs in the feed.     

Trypanosoma cruzi nucleoside triphosphate diphosphohydrolase 1 (TcNTPDase-1) biochemical characterization,immunolocalization and possible role in host cell adhesion

Previous work has suggested that Trypanosoma cruzi diphosphohydrolase 1 (TcNTPDase-1) may be involved in the infection of mammalian cells and serve as a potential target for rational drug design. In this work, we produced recombinant TcNTPDase-1 and evaluated its nucleotidase activity, cellular localization and role in parasite adhesion to mammalian host cells. TcNTPDase-1 was able to utilize a broad range of triphosphate and diphosphate nucleosides. The enzyme's K_m for ATP (0.096 mM) suggested a capability to influence the host's ATP-dependent purinergic signaling. The use of specific polyclonal antibodies allowed us to confirm the presence of TcNTPDase-1 at the surface of parasites by confocal and electron microscopy. In addition, electron microscopy revealed that TcNTPDase-1 was also found in the flagellum, flagellum insertion region, kinetoplast, nucleus and intracellular vesicles. The presence of this enzyme in the flagellum insertion region and vesicles suggests that it may have a role in nutrient acquisition, and the widespread distribution of TcNTPDase-1 within the parasite suggests that it may be involved in other biological process. Adhesion assays using anti-TcNTPDase-1 polyclonal antibodies as a blocker or purified recombinant TcNTPDase-1 as a competitor revealed that the enzyme has a role in parasite–host cell adhesion. These data open new frontiers to future studies on this specific parasite–host interaction and other unknown functions of TcNTPDase-1 related to its ubiquitous localization.     

Design and synthesis of 1,2,4‐triazolo[1,5‐a]pyrimidine derivatives as PDE 4B inhibitors endowed with bronchodilator activity

A series of 1,2,4‐triazolo[1,5‐a]pyrimidine derivatives was designed, synthesized, and screened for their phosphodiesterase (PDE 4B) inhibitory activity and bronchodilation ability. Compound 7e showed 41.80% PDE 4B inhibition at 10 µM. Eight compounds were screened for their bronchodilator activity, where compounds 7f and 7e elicited promising bronchodilator activity with EC₅₀ values of 18.6 and 57.1 µM, respectively, compared to theophylline (EC₅₀ = 425 µM). Molecular docking at the PDE 4B active site revealed a binding mode and docking scores comparable to those of a reference ligand, consistent with their PDE 4B inhibition activity.     

Partial thrombosis of the inferior vena cava in a patient with non-Hodgkin lymphoma and history of lumbar spine surgery

Complete or partial thrombosis of the inferior vena cava is usually due to pre-existing malformation of the vessel, malignant tumors, ascending thrombosis, or thrombophilic disorders. We report the case of an 81-year-old woman, in whom a partial thrombosis of the vena cava was observed in the CT scan when re-staging was performed after six cycles of R-CHOP because of high-grade malignant non-Hodgkin lymphoma. Before chemotherapy was started, the patient had undergone an operation of the lumbar spine using cement augmentation. Retrospective analysis showed that cement had penetrated a segmental vein and spilled into the vena cava leading to formation of an adhering blood thrombus. The patient was free of symptoms and anticoagulation was started. Spillage of cement frequently occurs in the process of vertebroplasty and kyphoplasty and may result in serious sequelae. As these procedures are increasingly being used, physicians should be aware of these complications if a patient presents with thrombosis of the caval vein or signs of pulmonary embolism.     

Angiographic lesion severity and subsequent myocardial infarction

We sought to determine the angiographic severity of coronary lesions leading to ST-segment elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI) with a focus on determining the impact of interval from initial angiogram to subsequent clinical event. In the late 1980s angiographic data on lesion characteristics that culminated in STEMI and NSTEMI were obtained from angiograms obtained several months before MI. It is not clear whether the conclusions on lesion severity would be different if elapsed interval from baseline angiogram to clinical event was factored in the analysis. From 2003 through 2010, we identified 84 patients with NSTEMI and 41 patients with STEMI in vessels without previous intervention. These patients had ≥1 previous angiographic study at our center. Angiograms were reanalyzed with quantitative coronary angiography, and relevant clinical data were obtained from medical records. Similar to previous studies, 71% of patients with STEMI and 63% of patients with NSTEMI had <50% baseline stenosis at the culprit site when the interval from initial angiogram to MI was >3 months. Interestingly, lesions that led to STEMI ≤3 months after evaluation were more severe than those leading to STEMI in >3 months (59 ± 31% vs 36 ± 21%, p = 0.02) with 57% of lesions having >50% stenosis. Although most MIs occurred at sites that did not have significant obstruction when examined >3 months before MI, most baseline lesions showed significant luminal narrowing when examined ≤3 months before STEMI. In conclusion, high-grade coronary stenosis may be an important predictor of STEMI in subsequent months.     

Up-regulation of a HOXA-PBX3 homeobox-gene signature following down-regulation of miR-181 is associated with adverse prognosis in patients with cytogenetically abnormal AML

Increased expression levels of miR-181 family members have been shown to be associated with favorable outcome in patients with cytogenetically normal acute myeloid leukemia. Here we show that increased expression of miR-181a and miR-181b is also significantly (P < .05; Cox regression) associated with favorable overall survival in cytogenetically abnormal AML (CA-AML) patients. We further show that up-regulation of a gene signature composed of 4 potential miR-181 targets (including HOXA7, HOXA9, HOXA11, and PBX3), associated with down-regulation of miR-181 family members, is an independent predictor of adverse overall survival on multivariable testing in analysis of 183 CA-AML patients. The independent prognostic impact of this 4-homeobox-gene signature was confirmed in a validation set of 271 CA-AML patients. Furthermore, our in vitro and in vivo studies indicated that ectopic expression of miR-181b significantly promoted apoptosis and inhibited viability/proliferation of leukemic cells and delayed leukemogenesis; such effects could be reversed by forced expression of PBX3. Thus, the up-regulation of the 4 homeobox genes resulting from the down-regulation of miR-181 family members probably contribute to the poor prognosis of patients with nonfavorable CA-AML. Restoring expression of miR-181b and/or targeting the HOXA/PBX3 pathways may provide new strategies to improve survival substantially.