Transplant arteriosclerosis: an enigmatic disease due to a misnomer

Solid organ transplantation across the allogeneic barrier, pioneered by Thomas Starzl, has by now become a common medical procedure. Unfortunately, the number of donor organs lost due to transplant arteriosclerosis (chronic rejection), remains significant and unchanged for decades. We argue that designation of transplant arteriosclerosis as chronic rejection, and its classification as a delayed long-lasting reaction of recipient immune effectors against donor alloantigens have given us a wrong impression that we have identified the necessary cause/pathogenesis of the tissue pathology. However, whatever treatment options we have in the anti-rejection toolbox, despite their success in treating classical rejection, do not work for the transplant arteriosclerosis. Yet, the scientific community has continued to conceptualize and approach the pathology within the alloimmunity model. Due to unproductive research from the alloimmunity and rejection perspective, the number of transplanted hearts lost due to this pathology today is almost the same as it was fifty years ago. We believe that this phenomenon falls under the rubric of linguistic relativity, and that language we chose to name the disease has restricted our cognitive ability to solve the problem. While the initial perception of the transplant arteriosclerosis as chronic rejection was logical and scientific, the subsequent experience revealed that such perception and approach have been fruitless, and likely are incorrect. Considering our tragic failure to prevent and treat the delayed arterial pathology of donor organs using all available knowledge on alloimmunity and rejection, we must finally disassociate the former from the latter. The only way to start this uncomfortable process is to change the words we are using; particularly, the words we chose to name the disease. We have to step out of the alloimmunity rejection box.Comment: 19 pages, 2 figure

The role of intraoperative angiography in the treatment of an acute impassability of the lower extremity artery

Objective. To compare the results of surgical treatment of patients, suffering an acute impassability of the lower extremity arteries (LEA) , using and not using intraoperative angiography. Materials and methods. Comparative analysis of the surgical treament results was done in the Centre of Vascular Surgery of Clinical Hospital “Feofania”, where in 2010-2017 yrs 119 patients, suffering an acute impassability of the LEA, were treated. All 119 patients investigated were divided into two groups: the Group I - 70 (58.8%) patients, in whom open thrombectomy, using Fogarty catheter, was performed to correct an acute ischemia of the lower extremity, and the Group II - 49 (41.2%) patients, in whom open thrombectomy, using Fogarty catheter, was followed by the control intraoperative angiography. Taking into account the results of angiography after thrombectomy, the balloon angioplasty was conducted, open surgical interventions on the arteries or thrombectomy only. Results. Performance of intraoperative angiography after thrombectomy gives possibility to determine the origin of an acute impassability of the arteries precisely, to accomplish intraoperative roentgenological control of the thrombectomy conduction  and to estimate its quality, to establish a substantiated indications for endovascular and open surgical interventions on the arteries in presence of their stenotic-occlusive affections on background of atherosclerotic process. Expediency of application of intraoperative angiography was witnessed by trustworthily higher rate of thrombectomy performance with positive immediate result in the patients of Group II (97.9%), comparing with the patients of Group I (88.6%) (p < 0.05), as well as the recurrence rate for an acute arterial impassability during a year, which was trustworthily higher in the Group I patients, comparing with the Group II patients – 30.7 and 8.2% (p < 0.001), accordingly. Conclusion. Application of intraoperative angiography and performance of interventions on the arteries in accordance to indications while doing thrombectomy for an acute impassability of the LEA gives possibility to enhance the rate of immediate positive results of the operation and to lower the recurrence rate for an acute arterial impassability during a year trustworthily

Structural and transport properties of GaAs/delta<Mn>/GaAs/InxGa1-xAs/GaAs quantum wells

We report results of investigations of structural and transport properties of GaAs/Ga(1-x)In(x)As/GaAs quantum wells (QWs) having a 0.5-1.8 ML thick Mn layer, separated from the QW by a 3 nm thick spacer. The structure has hole mobility of about 2000 cm2/(V*s) being by several orders of magnitude higher than in known ferromagnetic two-dimensional structures. The analysis of the electro-physical properties of these systems is based on detailed study of their structure by means of high-resolution X-ray diffractometry and glancing-incidence reflection, which allow us to restore the depth profiles of structural characteristics of the QWs and thin Mn containing layers. These investigations show absence of Mn atoms inside the QWs. The quality of the structures was also characterized by photoluminescence spectra from the QWs. Transport properties reveal features inherent to ferromagnetic systems: a specific maximum in the temperature dependence of the resistance and the anomalous Hall effect (AHE) observed in samples with both "metallic" and activated types of conductivity up to ~100 K. AHE is most pronounced in the temperature range where the resistance maximum is observed, and decreases with decreasing temperature. The results are discussed in terms of interaction of 2D-holes and magnetic Mn ions in presence of large-scale potential fluctuations related to random distribution of Mn atoms. The AHE values are compared with calculations taking into account its "intrinsic" mechanism in ferromagnetic systems.Comment: 15 pages, 9 figure

Observation of the enhancement of parametric radiation under conditions of the grazing incidence of relativistic electrons on the crystal surface

The enhancement of the yield of parametric X-ray radiation from 7-MeV electrons incident at a grazing angle on the silicon crystal surface has been experimentally detectedyesBelgorod State Universit