[Development and assessment of efficacy of L-polylactide matrix for creation of a tissue-engineered vascular graft]. / Razrabotka i otsenka éffektivnosti matritsy iz L-polilaktida dlia sozdaniia tkaneinzhenernogo sosudistogo implantata.

In order to create a tissue-engineered vascular graft we elaborated a matrix consisting of nanofibres of biodegradable polymer L-polylactide. We worked out the methodology of crystallization of the matrix on a rod, making it possible to manufacture specimens possessing strength and deformity characteristics superior to those of native vessels. This was followed by a series of chronic experiments on implanting the elaborated matrix into the abdominal aorta of rats for the duration of up to 16 months. We obtained satisfactory parameters of the patency of the matrices (71%). According to the findings of histological examination, in the course of time there occurred biodegradation of the matrix and formation of a new vascular wall, with no evidence of either inflammation or neointimal hyperplasia in the zone of the anastomoses. Resorption of the polymeric fibres commenced 12 weeks after exposure and completely terminated after 64 weeks. By that time, both neointima and neoadventitia were formed, whose composition and structure were close to those of the native vessel. Insufficiently high mechanical properties of the zone of reconstruction turned out to be the cause of the formation of aneurysms.

Tissue-Engineered Vascular Graft of Small Diameter Based on Electrospun Polylactide Microfibers.

Tubular vascular grafts 1.1 mm in diameter based on poly(L-lactide) microfibers were obtained by electrospinning. X-ray diffraction and scanning electron microscopy data demonstrated that the samples treated at T = 70°C for 1 h in the fixed state on a cylindrical mandrel possessed dense fibrous structure; their degree of crystallinity was approximately 44%. Strength and deformation stability of these samples were higher than those of the native blood vessels; thus, it was possible to use them in tissue engineering as bioresorbable vascular grafts. The experiments on including implantation into rat abdominal aorta demonstrated that the obtained vascular grafts did not cause pathological reactions in the rats; in four weeks, inner side of the grafts became completely covered with endothelial cells, and fibroblasts grew throughout the wall. After exposure for 12 weeks, resorption of PLLA fibers started, and this process was completed in 64 weeks. Resorbed synthetic fibers were replaced by collagen and fibroblasts. At that time, the blood vessel was formed; its neointima and neoadventitia were close to those of the native vessel in structure and composition.

Vascular Prostheses Based on Nanofibers from Aliphatic Copolyamide.

Tubular grafts based on nanofibers of copolymer of ε-caprolactam and hexamethylendiaminadipate were obtained by the electrospinning method. The strength of materials based on the dry nanofibers was 6.2 MPa with elongation at break of 133%, or 7.5 MPa and 299% in saline, respectively. The pressure value at which liquid started seeping through the tube wall was P = 10 kPa. Absence of cytotoxicity was proved, as well as adhesion and proliferation of mesenchymal stem cells on the surface. Tubes with inner diameter of 1 mm were tested in vivo in rat abdominal aorta. A layer of endothelial cells was shown to form on the inner side of the prosthesis after 30 days. There was no evidence of stenosis or dilatation of the prosthesis after 14 months with observation of endothelial and subendothelial layers.

[Bacterial infections in the early period after allogeneic bone marrow transplantation].

AIM: To study the incidence and risk factors of bacterial infections and the efficiency of empirical antibacterial therapy in patients in the early period after allogeneic hematopoietic stem cell transplantation (allo-HSCT). SUBJECTS AND METHODS: The study included 155 patients who had undergone allo-HSCT. Myeloablative conditioning was used in 39% of the patients. All the patients with neutropenia (NP) received antibiotic prophylaxis with fluoroquinolones until recovery of white blood cell counts or before systemic antibiotic therapy. Antibiotic therapy and a change of antibiotics were considered effective in achieving persistent apyrexia and positive clinical changes. RESULTS: The incidence of febrile neutropenia (FNP) in the patients after allo-HSCT was 63%. The duration of grade 4 leukopenia did not depend on the conditioning regimen. Neutropenic fever was noted in 68% of the patients with NP lasting longer 10 days. In shorter-duration NP, the rate of fever was 52%. Among the patients with mucositis, the frequency of FNP episodes was significantly higher (69% versus 52%; p=0.02). The diverse spectrum of isolated bacteria was represented as gram-positive cocci in 45% of cases; Klebsiella pneumoniae and Enterobacter cloacae were more common among gram-negative ones (24%). The efficiency of empirical antibiotic therapy was 57% (25% for monotherapy, 53% for combined treatment regimens); the early mortality was 2%. CONCLUSION: Infection-related FNP is noted in 68% of the patients in the early posttransplantation period and the risk factors of its development are NP duration, oral colonization with pathogens, and the absence of invasive mycosis after allo-HSCT. Antibacterial prophylaxis significantly decreases the incidence of bacterial complications. Empirical monotherapy with third- or fourth-generation cephalosporins and carbapenems against infections in a transplantation patient is as effective as their combination with aminoglycosides.

[ABCG1 transporter gene expression in peripheral blood mononuclear cells of patients with atherosclerosis].

Accumulation of cholesterol in arterial wall macrophages is a main hallmark of atherosclerosis. The ABCG1 transporter mediates cholesterol efflux to high density lipoproteins (HDL) and plays an important role in macrophage foam cell formation. The goal of our study was to investigate the potential role of ABCG1 in atherosclerosis development in humans. ABCG1 gene expression has been examined in leukocytes, monocytes and monocyte-derived macrophages of patients with atherosclerosis and in the control group. Real time PCR and Western blotting were used to determine ABCG1 mRNA and ABCG1 protein levels. Monocyte ABCG1 mRNA level was inversely correlated with the rate of artery occlusion (r = -0.45, P = 0.016). Patients with 100% artery occlusions had decreased monocyte ABCG1 mRNA levels compared to patients who had smaller plaques and controls (P < 0.05). ABCG1 mRNA (P < 0.001) and ABCG1 protein (P < 0.05) levels in macrophages of patients with coronary artery stenosis were significantly reduced compared to the control group. No significant correlation between the ABCG1 gene expression in mononuclear cells and HDL cholesterol concentration has been found. Our study suggests that decrease in the ABCG1 gene expression in macrophages is associated with atherosclerosis.

[Recellularization of tissue engineered vascular grafts in perfusion bioreactor].

Small diameter tissue engineered vascular grafts could be a potential solution to the shortage of vascular substitutes in reconstructive cardiovascular surgery. Previously, we have developed a decellularization method for human umbilical arteries, which could be used as a scaffold in vascular tissue engineering. Objective of the study was to optimize the recellelularization of decellularized scaffolds with mesenchymal stem cells. In the study, the possibility of cell growth on decellularized vessel has been shown. We also has proved that the use of perfusion-bioreactor improves the results of recellularization.

[Radical breast resection with skin-muscular latissimus dorsi flap grafting].

The oncological breast surgeries with single-stage replacement of the lost volume by means of autogeneous tissue using distant flaps grafting (particularly by skin--muscular flaps of the latissimus dorsi) allow obtaining satisfactory and stable aesthetic results without the decrease of indices of relapse-free and general survival. The early results of the application of the skin-muscular flaps of the latissimus dorsi for single-stage breast reconstruction after radical breast resection are presented in this work in 3 patients with breast cancer. The technique allows performance of the extensive radical resection with single-stage grafting in patients with breast cancer and obtaining an objective clinical response against the background of neoadjuvant therapy with subsequent applying radiation therapy and systemic treatment.

[Allogeneic hematopoietic stem cell transplantation for acute myeloblastic leukemia in first remission].

AIM: To evaluate the efficiency of allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with acute myeloblastic leukemia in first remission depending on the regimens of conditioning, the source of a graft, and the characteristics of a donor and a recipient. SUBJECTS AND METHODS: In 66 treated patients, including from partially HLA-mismatched relatives (n=4), the efficiency of allo-HSCT from related donors (n=26) and unrelated donors (n=40), were compared. According to cytogenetic findings, 7 (11%), 31 (47%), and 10 (15%) patients belonged to low-, intermediate-, and high-risk groups, respectively. RESULTS: Five-year overall survival (OS) and mortality associated with transplantation were 56 and 22% for allo-HSCT from related donors, 68 and 23% for that from HLA-matched donors, and 71 and 25% for that from partially HLA-mismatched donors, respectively (p=0.8 and p=0.7). The relapse risk after allo-HSCT from unrelated donors was significantly lower than after that from related donors (13 and 35%, respectively; p=0.8). Univariate analysis showed that the OS rates depended on the cytogenetic risk group (OS was 24 and 64% in the high- and intermediate-risk groups, respectively (p=0.027). The relapse risk in chronic graft-versus-host reaction (GVHR) and in grade 3 acute GVHR (p=0.01) was shown to be less than that in grades 1-2 acute GVHR (p=0.06). CONCLUSION: OS rates after allo-HSCT from related and unrelated donors were comparable and unrelated to the source of a graft, the regimen of conditioning, and other characteristics of a donor and a recipient.

[Efficacy of donor lymphocyte infusion in patients after different types of allogeneic hematopoietic stem cell transplantation].

AIM: To evaluate the efficacy of donor lymphocyte infusion (DLI) to prevent and treat recurrences in patients after different types of allogeneic hematopoietic stem cell transplantation (allo-HSCT). SUBJECTS AND METHODS: Data from 118 patients with malignant blood diseases were analyzed. Allo-HSCTs from HLA-matched related donors (n=49), HLA-matched unrelated donors (n=50), partially HLA-matched unrelated donors (n=2), and haploidentical donors (n=24) were performed. The indications for DLI were underlying disease relapse (59 DLIs), resistant disease course (n=40), minimal residual disease (n=1 6), falling donor chimerism (n=1 5), and recurrence prevention (n=1 3). RESULTS: Therapy response was obtained after 57 (44%) DLls. There were 36 (25%) and 30 (21%) cases of acute and chronic graft-versus-host reactions (GVHR), respectively. The use of DLI from HLA-matched donors, its performance in the periods of D+100 to one year after allo-HSCT, a donor chimerism level of over 90% at the moment of DLI, the administration of the initial DLI dose of below 1.10(6) CD3+/kg, and the development of chronic GVHR after DLI were associated with the highest rate of therapy responses. The overall survival rates of patients with DLI were significantly influenced by factors, such as DLI periods, donor chimerism levels at DLI, and the development of chronic CVHR after DLI. CONCLUSION: The choice of the optimal dose of cells, the periods of DLI and its preventive administration improve prognosis in patients after allo-HSCT. The occurrence of acute GVHR is affected by the degree of HLA matching and the type of a donor. The development of chronic GVHR after DLI is associated with the highest rate of responses to DLI and higher survival rates.

[Extracorporeal photopheresis in the treatment of patients with refractory chronic graft-versus-host disease after allogeneic bone marrow transplantation].

AIM: To evaluate the efficiency of extracorporeal photopheresis (ECP) in the treatment of patients with refractory chronic graft-versus-host disease (cGVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT). SUBJECTS AND METHODS: The study included 49 patients aged 2 to 55 years. Allo-HSCT was carried out in 38 (79%) patients with acute leukemias, 5 (10%) with chronic leukemias, 4 (8%) with myelodysplastic syndrome/myeloproliferative disease, and 2 (3%) with other hematologic diseases. The patients included in the study had glucocorticosteroid (GCS)-refractory disseminated cGVHD or a history of severe complications from GCS therapy. RESULTS: When evaluating the efficiency of therapy, its response was recorded in 37 (77%) cases; the best results were obtained in patients with hepatic (82%), mucosal (76%), and skin (74%) lesions. The mean severity according to the cGVHD Working Group, National Institutes of Health, and a platelet level of more than 100.10(9)/1 were defined as factors improving a therapy response. In the patients receiving ECP, the overall survival was 70%. The latter was higher in the group of patients who had responded to ECP therapy without involving the gastrointestinal tract in the cGVHD process and in those receiving a combination of ECP and other immunosuppressive drugs. CONCLUSION: ECP is an effective treatment for patients with refractory cGVHD, it may be used in those with a history of severe complications from GCS therapy. ECP allows the dose of GCS to be reduced to the point of complete discontinuation.

[Invasive mycoses during hematopoietic stem cell transplantation].

AIM: To define the frequency, etiology, and risk factors of invasive mycoses (IM) in patients with allogeneic (allo) and autologous (auto) hematopoietic stem cell transplantation (HSCT) and to evaluate the impact of IM on overall survival (OS). MATERIALS AND METHODS: Data on 356 patients after allo-HSCT (n = 237) and auto-HSCT (n = 119) from 2000 to 2010 were analyzed. The diagnosis of IM was established according to the EORTC/MSG 2008 criteria. RESULTS: The incidence of myocardial infarction (MI) was 19.1%; that was 23.2 and 10.9% in allo-HSCT and auto-HSCT recipients, respectively. The incidence of MI following allo-HSCT was significantly higher than that after auto-HSCT. Aspergillus spp. (82.3%), Candida spp. (11.8%), zygomycetes (Mucor spp., Rhizopus spp.) (4.4%), and Cryptococcus neoformans (1.5%) are involved in the etiology of MI. Its risk factors are acute lymphoblastic leukemia; non-myeloablative conditioning regimen; use of fludarabine and antilymphocyte globulin; peripheral blood stem cells as a source for grafting; long-term lymphopenia, neutropenia; use of granulocyte colony-stimulating factor (G-CSF); acute graft-versus-host reaction; grade 3-4 mucositis; infections, such as cytomegalovirus, sepsis. The development of MI in HSCT recipients did not significantly reduce one-year OS after allo-HSCT and auto-HSCT--53.6 and 55% and 86.7 and 90.3% (with and without MI, respectively). In patients with invasive aspergillosis, OS (12 weeks after IM being diagnosed) was significantly longer in those with other invasive mycoses (91.3 and 50%, respectively). CONCLUSION: The incidence of MI after allo-HSCT was higher than that after auto-HSCT. MI induced by the fungal genus Aspergillus spp. was most common. Along with known risk factors, there was a poor prognostic factor, such as G-CSF. The development of MI failed to affect one-year OS, which was indicative of the adequate quality of its early diagnosis and therapy. The prognosis was poor in patients with invasive candidiasis, zygomycosis, and cryptococcosis. Investigations need to be continued to specify the reasons for high morbidity rates and the factors provoking discussion by investigators worldwide.

[Carotid endarterectomy and endovascular angioplasty with stenting in patients with atherosclerotic stenoses and occlusions of the internal carotid artery].

The authors made a comparative assessment of carotid endarterectomy and endovascular angioplasty with stenting in patients with atherosclerotic lesions of the carotid arteries. The authors consider that indications to stenting and carotid endarterectomy are identical in patients with stenose and occlusions of the carotid arteries. Contraindications to angioplasty of carotid arteries are determined. It was shown that angioplasty and stenting in atherosclerotic lesions of the carotid arteries was an effective method with a less number of complications as compared with carotid endarterectomy and are thought to be an adequate alternative to open surgical method of treatment of patients with stenoses and occlusions of the carotid arteries.

[Early ischemic preconditioning against focal transient and permanent brain ischemia in rats: role of collateral circulation].

We hypothesize that early ischemic preconditioning (IPC) can afford protection against focal brief and prolonged cerebral ischemia with subsequent reperfusion as well as permanent brain ischemia in rats by amelioration of regional cerebral blood flow. Adult male Wistar rats (n=97) were subjected to transient (30 and 60 minutes) and permanent middle cerebral artery (MCA) occlusion. IPC protocol consisted of two episodes of 5-min common carotid artery occlusion + 5-min reperfusion prior to test ischemia either followed by 48 hours of reperfusion or not. Triphenyltetrazolium chloride and Evans blue were used for delineation of infarct size and anatomical area at risk (comprises ischemic penumbra and ischemic core), respectively. Blood flow in the MCA vascular bed was measured with use of Doppler ultrasound. The IPC resulted in significant infarct size limitation in both transient and permanent MCA occlusion. Importantly, IPC caused significant reduction of area at risk after 30 min of focal ischemia as compared to controls [med(min-max) 11.4% (3.59-2 0.35%) vs. 2.47% (0.8-9.31%), p = 0.018] but it failed to influence area at risk after 5 min of ischemia [med(min-max) 7.61% (6.32-10.87%) vs. 8.2% (4.87-9.65%), p > 0.05]. No differences in blood flow were found between IPC and control groups using Doppler ultrasound. This is suggestive of the fact that IPC does not really influence blood flow in the large cerebral arteries such as MCA but it might have some effect on smaller arteries. It seems that, along with well established cytoprotective effects of IPC, IPC-mediated reduction of area at risk by means of improvement in local cerebral blood flow may contribute to infarct size limitation after focal transient and permanent brain ischemia in rats.

[Intimal hyperplasia within a vascular anastomosis].

Intimal hyperplasia (IH) appears to rank high amongst plausible causes of reconstructed arteries restenosis. It always occurs in the area of a surgical intervention on a vessel in response to a mechanical lesion. IH is the cause of thrombosis in 15 to 50% of cases following vascular reconstruction during the first year after the operation (with the exception of early thromboses, which are probably caused by an improperly performed interventional technique). Of a wide variety of clinical situations leading to development of IH in the vascular wall, for the purposes of the present review, we singled out the problem concerning the onset and development of this tissue reaction in intervascular anastomoses, which is currently one of the most important issues. Analysing the publications on the problem concerned showed that amongst significantfactors influencing the development of IH in the anastomosis, the investigators single out different parameters of the anastomoses, configuration (either an end-to-end or an end-to-side anastomosis, the use of special inserts and patches within the latter), as well as the use of autologous or synthetic conduits, blanket suture or interrupted suture, peculiarities of local haemodynamics (linear blood flow rate, distribution of parietal fraction forces, zones of stagnation and flow separation), etc. To a certain degree, the published data are rather controversial. There remain many problems, which are either unaddressed as yet, or insufficiently studied, if at all. For instance, while establishing an anastomosis between a bypass graft and an artery, surgeons often resort to endarterectomy. It is not known whether or not this technique would influence the IH pattern in the anastomosis concerned. Neither is it clear whether the high velocity flow exerts a direct damaging action upon the endothelium, whether it promotes the development of IH in the area of the lesion, and if affirmative, then what the mechanisms of this effect really are. Not studied is the role of various types of synthetic fibres and synthetic grafts (except PTFE), various kinds of suture material in the development of IH in the zone of a vascular anastomosis concerned. This of course is far from being a complete list of the challenges requiring further investigation.

[Recovery of peripheral blood lymphocytes in patients with hematological diseases after allogenic non-relative transplantation of hemopoietic stem cells].

AIM: To define impact of lymphopoiesis state on the results of transplantation of hemopoietic stem cells (THSC) by assessment of kinetics of lymphocyte count recovery in early posttransplantation period; to study correlation between THSC results and changes in composition of lymphocyte subpopulation. MATERIAL AND METHODS: Recipients of 122 non-relative THSC entered the trial. The recipients were adults with various hematological malignancies. RESULTS: Allogenic non-relative THSC leads to deep and long-lasting lymphopenia, low count of all lymphocyte subpopulations and, as a result, to marked impairment of antiinfectious and antitumor immune response. Kinetics of lymphopoiesis recovery depended on some clinical factors. Of most importance were duration of the disease before THSC, HLA donor and recipient compatibility, the source of stem cells, lymphocyte count in the transplant, administration of immunosuppressive drugs. Conduction of non-myeloablative regimens of conditioning did not reduce severity and duration of lymphopoiesis suppression. The time of lymphoid subpopulations count recovery had a significant influence on THSC results. Long-term lymphopenia increased the risk of severe infectious complications and recurrence. Low (under 500 lymphocytes in 1 mcl) lymphocyte level in peripheral blood one month after the transplantation was a death risk factor for patients after THSC. CONCLUSION: Dynamics of the recovery of lymphocyte subpopulations can be used for formulating policy of adaptive immunotherapy in patients after THSC.

[On the anatomical terms used for description of brain arteries and discrepancy between them and anatomical nomenclature]. / Ob anatomicheskikh nazvaniiakh, ispol'zuemykh pri opisanii mozgovykh arterii, i ikh nesootvetstvii anatomicheskoi terminologii.

The following terms are used in Russian literature to designate arteries, which carry blood into the brain: brachiocephalic arteries, aortic arch branches, main cerebral arteries (arteries of the head), extra- and intracranial cerebral arteries, precerebral arteries. All terms either have substantial drawbacks or conflict with the adopted anatomical terminology. These discrepancies become far more significant in view of publication of "Terminologia Anatomica" (New York, 1998). We suggest to discuss the possibility to use universal terminology for the designation of the system of the arteries, supplying the brain. We propose to designate truncus brachiocephalicus, common carotid and subclavian arteries, internal carotid and vertebral arteries with their branches including arterial network on the brain surface by the term "the conducting arteries", whereas small branches, which pierce the brain matter are to be named "the penetrating arteries" (T.M. Sundt et al., 1976). Considering the Greek word "encephalon", which means "the brain", all the arteries of the brain could be designated as encephalic, while conducting arteries--as preencephalic, and intracerebral (penetrating) arteries--as intraencephalic.

[A method of phalloplasty using a non-free skin-fat flap from the thigh]. / Sposob falloplastiki nesvobodnym kozhno-zhirovym loskutom bedra.

The authors propose a method of phalloplasty with a full-thickness flap on the vasculo-nervous pedicle taken from the femur. The method of raising such a flap and the technique of its displacement to the area of the pubic articulation if described. This method of phalloplasty was used in 10 patients aged 19-36 years. In all of them full taking of the transplant was noted. Good cosmetic and functional results were obtained.