[Endoscopic intraluminal treatment of pancreatic fluid collections after pancreas transplantation]. / Endoskopicheskoe vnutriprosvetnoe lechenie pankreaticheskikh zatekov posle transplantatsii podzheludochnoi zhelezy.

OBJECTIVE: To improve the outcomes after pancreas transplantation complicated by pancreatitis using percutaneous drainage and endoscopic stenting of the main pancreatic duct. MATERIAL AND METHODS: There were 64 transplantations of the pancreatoduodenal complex between January 1, 2012 and December 31, 2021 at the Sklifosovsky Research Institute for Emergency Care. In 11 (17.2%) cases, early postoperative period was complicated by acute pancreatitis and parapancreatic fluid accumulations. Of these, 7 patients underwent ultrasound-guided percutaneous drainage of focal destructions. This procedure was effective and did not require additional treatment. In 4 patients, debridement and drainage were ineffective and required additional endoscopic stenting of the main pancreatic duct. RESULTS: All patients underwent percutaneous drainage of peripancreatic fluid collections and subsequent fistulography. All patients had inhomogeneous cavities with irregular shape and volume of 19.6±1.8 cm3. In 3 (75%) out of 4 patients, there was a passage of contrast agent into the main pancreatic duct of the graft and donor duodenal stump. We did not find contrast enhancement of ductal system in 1 (25%) patient since filling of the cavity with a contrast agent was not tight. Sensitivity of this method for detecting pancreatic ductal defects was 75%. Indications for stenting of the main pancreatic duct were established in 22.5±9.6 days after transplantation. Drainage and debridement were ineffective in 2 (50%) patients. In other 2 (50%) patients, peripancreatic fluid collections enlarged. All patients underwent endoscopic stenting of the main pancreatic duct. CONCLUSION: Endoscopic stenting of the main pancreatic duct of the donor pancreas combined with percutaneous drainage of peripancreatic fluid accumulations is a highly effective and minimally invasive approach for fluid collections after transplantation of the pancreatoduodenal complex. This method also minimizes the incidence of postoperative complications. Thanks to this method, we avoided redo open surgeries in all cases.

Strong Interminivalley Scattering in Twisted Bilayer Graphene Revealed by High-Temperature Magneto-Oscillations.

Twisted bilayer graphene (TBG) provides an example of a system in which the interplay of interlayer interactions and superlattice structure impacts electron transport in a variety of nontrivial ways and gives rise to a plethora of interesting effects. Understanding the mechanisms of electron scattering in TBG has, however, proven challenging, raising many questions about the origins of resistivity in this system. Here we show that TBG exhibits high-temperature magneto-oscillations originating from the scattering of charge carriers between TBG minivalleys. The amplitude of these oscillations reveals that interminivalley scattering is strong, and its characteristic timescale is comparable to that of its intraminivalley counterpart. Furthermore, by exploring the temperature dependence of these oscillations, we estimate the electron-electron collision rate in TBG and find that it exceeds that of monolayer graphene. Our study demonstrates the consequences of the relatively small size of the superlattice Brillouin zone and Fermi velocity reduction on lateral transport in TBG.

[Advanced glycation end products and oxidative stress as a basis for metabolic abnormalities in patients with type 1 diabetes after successful simultaneous pancreas-kidney transplantation].

AIM: To compare advanced glycation end-products (AGE, RAGE) and 3-nitrotyrosine (3-HT) in patients with DM 1 after successful simultaneous pancreas-kidney transplantation (SPK) and kidney transplantation alone (KTA). To assess relationship between levels of AGE, RAGE, 3-HT and renal transplant (RT) function, carbohydrate and mineral metabolism. MATERIALS AND METHODS: The study included 58 patients who received kidney transplantation in end-stage renal disease (ESRD). 36 patients received SPK. There were performed routine laboratory, examination of AGE, RAGE, 3-NT, parathyroid hormone (PTH), 25(OH)vitamin D, calcium, phosphorus, FGF23, osteoprotegerin (OPG), and fetuin-A levels. RESULTS: All patients after SPK reached normoglycemia (HbA1c 5.7 [5.3; 6.1] %; C-peptide 3.24 [2.29; 4.40] ng/ml) with the achievement of significant difference vs patients after KTA. Arterial hypertension (AH) was more frequent in recipients of SPK before transplantation than after (p=0.008). AH also persisted in greater number of cases in patients after KTA than after SPK. Patients after SPK had higher AGE (р=0.0003) and lower RAGE (р=0.000003) levels. OPG in patients after SPK was significantly higher (р=0.04). The correlation analysis revealed significant positive correlation between 3-HT and OPG (p0.05; r=0.30), RAGE and eGFR (r=-0.52), HbA1c (r=0.48), duration of AH (r=0.34), AGE with HbA1c (r=0.51). CONCLUSION: The results of the "metabolic memory" markers analysis may indicate their contribution to the persistence of the metabolic consequences of CKD and DM 1 after achievement of normoglycemia and renal function restoration and their possible participation in development of recurrent nephropathy, vascular calcification, and bone disorders.

[Surgical aspects of pancreas transplantation: exocrine drainage. Part 3]. / Khirurgicheskie aspekty transplantatsii podzheludochnoi zhelezy: otvedenie ekzokrinnogo sekreta transplantata. Chast' 3.

Exocrine drainage is an Achilles heel of pancreas transplantation. The author analyzed the outcomes of pancreas transplantations with different types of exocrine drainage in various centers (n=93). The article will ensure insight into evolution of techniques of exocrine drainage within the historical context and current state of this issue.

[Surgical aspects of pancreas transplantation: exocrine drainage. Part 2]. / Khirurgicheskie aspekty transplantatsii podzheludochnoi zhelezy: otvedenie ekzokrinnogo sekreta transplantata. Chast' 2.

Exocrine drainage is an Achilles heel of pancreas transplantation. The author analyzed the outcomes of pancreas transplantations with different types of exocrine drainage in various centers (n=93). The article will ensure insight into evolution of techniques of exocrine drainage within the historical context and current state of this issue.

[Surgical techniques of pancreas transplantation: exocrine drainage. Part 1]. / Khirurgicheskie aspekty transplantatsii podzheludochnoi zhelezy: otvedenie ekzokrinnogo sekreta transplantata. Chast' 1.

Exocrine drainage is an Achilles heel of pancreas transplantation. The author analyzed the outcomes of pancreas transplantations with different types of exocrine drainage in various centers (n=93). The manuscript ensures insight on the evolution and progress of exocrine drainage techniques in pancreas transplantation within the historical context and current state of the problem.

Publisher's Note: Anomalous Hall Effect in a 2D Rashba Ferromagnet [Phys. Rev. Lett. 117, 046601 (2016)].

This corrects the article DOI: 10.1103/PhysRevLett.117.046601.

[Endoscopic treatment of gastroduodenal perforations]. / Endoskopicheskoe lechenie gastroduodenal'nykh perforatsii.

A 93-year-old patient underwent endoscopic treatment of perforated duodenal ulcer after previous laparoscopic suturing complicated by failure of sutured defect. A self-expanding nitinol stent with partial polyurethane coating was used. Positive effect of the treatment was noted. Further study of this method and its clinical introduction in case of favorable results can significantly reduce the incidence of complications and mortality in patients with perforated gastroduodenal ulcers.

Acoustoelectric Study of Microwave-Induced Current Domains.

Surface acoustic waves (SAW) have been utilized to investigate the properties of a two-dimensional electron system subjected to a perpendicular magnetic field and monochromatic microwave radiation in the regime where the so-called microwave-induced zero-resistance states form. Contrary to conventional magnetotransport in Hall bar and van der Pauw geometries, the collimated SAW beam probes only the bulk of the electronic system exposed to this wave. Clear signatures appear in the SAW propagation velocity, corroborating that neither contacts nor sample edges are a root source for their emergence. By virtue of the directional nature of this probing method and with the assistance of theoretical modeling, we were able to demonstrate that the SAW response depends on the angle between its propagation vector and the orientation of domains that spontaneously form when zero-resistance is observed in transport. This confirms in unprecedented manner the formation of an inhomogeneous phase under these nonequilibrium conditions.

[Pancreas transplantation with isolated blood supply through the splenic artery]. / Transplantatsiia podzheludochnoi zhelezy s izolirovannym krovosnabzheniem po selezenochnoi arterii.

In multiple organ procurement, taking into consideration certain peculiarities of the vascular architectonics of the celiac trunk or an iatrogenic injury to the superior mesenteric artery, it is impossible to perform standard arterial reconstruction of a pancreas transplant with the use of a Y-shaped vascular allograft. This results in refusal from transplanting a potentially suitable organ. The purpose of our study was to assess the possibility of transplantation of the pancreatoduodenal complex with isolated blood supply via the splenic artery. Between January 2008 and November 2016, transplantation of the pancreas was carried out in a total of 20 patients (9 men and 11 women aged from 26 to 40 years, mean age 37.2±5.6 years). Depending on the number of the major arteries supplying the pancreas, the patients were divided into 2 groups. No statistically significant between-group differences in the parameters of volumetric blood flow determined by means of CT perfusion, in the majority of laboratory findings or therapeutic outcomes were revealed. Based on assessment of the function and quality of pancreatic blood supply, we proved feasibility of transplantation of the pancreatoduodenal complex with isolated blood supply through the splenic artery.

[Pancreas transplantation followed by stumpless duodenal exocrine drainage]. / Transplantatsiia podzheludochnoi zhelezy s bezkul'tevym duodenal'nym drenirovaniem.

Pancreas transplantation followed by stumpless duodenal exocrine drainage was performed in 2 patients. Primary kidney and pancreas graft function was noted in both cases. Two procedures of pancreas transplantation followed by stumpless duodenal exocrine drainage were carried out for the first time. Perhaps, absent donor duodenal stump has several advantages for the further course of postoperative period that may be confirmed in prospective trials.

[Treatment of postoperative ventral hernias in recipients of solitary organs]. / Lechenie posleoperatsionnykh ventral'nykh gryzh u retsipientov solidnykh organov.

AIM: To perform retrospective analysis of treatment of postoperative ventral hernias (PVH) in kidney and extrarenal organs recipients, to assess its safety and effectiveness. MATERIAL AND METHODS: Hernia repair has been performed in 84 PVH patients for the period from May 2006 to November 2017. The main group consisted of 41 patients (24 males, 17 females, mean age 55 (44; 59)) years with PVH due to previous transplantation. The control group included 43 PVH patients (21 males, 22 females, mean age 51 (50, 56)) years without previous transplantation. RESULTS: Incidence of surgical complications was similar in two groups: 63.4% in group 1 vs. 53.5% in group 2 (p>0.05). There were no significant differences in the incidence of surgical complications depending on immunosuppressive therapy and synthetic endoprosthesis deployment technique. CONCLUSION: Treatment of postoperative ventral hernias using synthetic endoprostheses in recipients of solid organs is effective and safe and should be considered as a preferable in treatment of this pathology.

Retroperitoneal Pancreas Transplantation With the Use of Duodenal Drainage via "Button Technique": First Clinical Practice (Case Report).

The persistent relative high incidence of duodenum-associated surgical complications significantly reduces pancreas grafts' (PG) and recipients' survival rates. A 31-year-old female patient underwent retroperitoneal pancreas transplantation with the use of PG exocrine drainage into the recipient's duodenum via the "button technique" approach. An uncomplicated postoperative period with satisfactory function of both transplants (pancreas and kidney) was noted. This was the 1st time ever that the transplantation was performed with the use of retroperitoneal placement of the pancreas transplant and duodenal drainage via the "button technique" approach. It is possible that the absence of the duodenal stump in the donor's transplant has a number of benefits in the postoperative period, which can be confirmed during the follow-up observations.

Anomalous Hall Effect in a 2D Rashba Ferromagnet.

Skew scattering on rare impurity configurations is shown to dominate the anomalous Hall effect in a 2D Rashba ferromagnet. The mechanism originates in scattering on rare impurity pairs separated by distances of the order of the Fermi wavelength. The corresponding theoretical description goes beyond the conventional noncrossing approximation. The mechanism provides the only contribution to the anomalous Hall conductivity in the most relevant metallic regime and strongly modifies previously obtained results for lower energies in the leading order with respect to impurity strength.

[Morphological diagnostics of fat embolism].

The present review of the literature concerns the problem of morphological diagnostics of fat embolism, i.e. mechanical obturation of multiple blood vessels with fat globules, that can be detected by a variety of methods including polarization microscopy, staining of native, frozen, and paraffin-embedded histological sections with the use of immunohistochemical techniques, electron microscopy, etc.

Spin-Selective Electron Quantum Transport in Nonmagnetic MgZnO/ZnO Heterostructures.

We report magnetotransport measurements on a high-mobility two-dimensional electron system at the nonmagnetic MgZnO/ZnO heterointerface showing distinct behavior for electrons with spin-up and spin-down orientations. The low-field Shubnikov-de Haas oscillations manifest alternating resistance peak heights which can be attributed to distinct scattering rates for different spin orientations. The tilt-field measurements at a half-integer filling factor reveal that the majority spins show usual diffusive behavior, i.e., peaks with the magnitude proportional to the index of the Landau level at the Fermi energy. By contrast, the minority spins develop "plateaus" with the magnitude of dissipative resistivity that is fairly independent of the Landau level index and is of the order of the zero-field resistivity.

Simultaneous pancreas-kidney transplantation with duodeno-duodenal anastomosis.

Simultaneous pancreas-kidney transplantation (SPKT) is now accepted as the method of choice for patients with insulin-dependent diabetes mellitus (type I) who have end-stage renal disease (ESRD). We believe that retroperitoneal positioning of the donor pancreas with the formation of duodeno-duodenal anastomosis is the most physiologically relevant. Starting in January 2008, the SPKT was chosen as the treatment method of 32 patients with diabetes mellitus. In 15 cases comprising group I (46.9%), the pancreas was placed intra-abdominally (including the formation of the duodeno-jejunal anastomosis). In the remaining 17 patients (53.1%) comprising group II, the pancreas was positioned retroperitoneally (including the formation of the duodeno-duodenal anastomosis). We compared the main parameters of the early postoperative period in these groups. There were no substantial differences between the groups in the prevalence of immunological (13.3% and 11.8%, P = .9), surgical (20% and 23.5%, P = .81), and infectious complications (20% and 5.9%, P = .23). On discharge there were no significant differences in the values of the following between the two groups, respectively: serum creatinine values, 112.7 ± 31.2 and 104.8 ± 54.6 µmol/L, P = .17; glomerular filtration rate, 73.5 ± 28.6 and 78.7 ± 24.9 mL/min, P = .55; α-amylase, 121.9 ± 63.6 and 150.1 ± 72.1 U/L, P = .27; pancreatic amylase, 102 ± 51.5 and 122.5 ± 75.4 U/L, P = .6; lipase, 115.4 ± 67.3 and 96 ± 65.7 U/L, P = .5; С-peptide, 4.44 ± 1.9 and 4.02 ± 2.4 ng/mL, P = .47; HbA1c, 5.45 ± 0.8% and 5.56 ± 1.12%, P = .9; and intact insulin, 12.2 ± 5.4 and 12.9 ± 8.8 mcIU/mL, P = .95). SPKT remains the best method of medical and social rehabilitation for patients who have diabetes mellitus (type-I) with ESRD. Compared to the classic method, we have seen no significant deviations in either of the following: the qualitative features marking the restoration of function of the two transplanted organs and/or the quality of compensation of carbohydrate metabolism, incidence of rejection, and graft loss. At the same time, retroperitoneal positioning of the pancreas exhibited lower repeat surgery rates.

Emergence of domains and nonlinear transport in the zero-resistance state.

We study transport in the domain state, the so-called zero-resistance state, that emerges in a two-dimensional electron system in which the combined action of microwave radiation and magnetic field produces a negative absolute conductivity. We show that the voltage-biased system has a rich phase diagram in the system size and voltage plane, with second- and first-order transitions between the domain and homogeneous states for small and large voltages, respectively. We find the residual negative dissipative resistance in the stable domain state.

Fully automated deformable registration of breast DCE-MRI and PET/CT.

Accurate characterization of breast tumors is important for the appropriate selection of therapy and monitoring of the response. For this purpose breast imaging and tissue biopsy are important aspects. In this study, a fully automated method for deformable registration of DCE-MRI and PET/CT of the breast is presented. The registration is performed using the CT component of the PET/CT and the pre-contrast T1-weighted non-fat suppressed MRI. Comparable patient setup protocols were used during the MRI and PET examinations in order to avoid having to make assumptions of biomedical properties of the breast during and after the application of chemotherapy. The registration uses a multi-resolution approach to speed up the process and to minimize the probability of converging to local minima. The validation was performed on 140 breasts (70 patients). From a total number of registration cases, 94.2% of the breasts were aligned within 4.0 mm accuracy (1 PET voxel). Fused information may be beneficial to obtain representative biopsy samples, which in turn will benefit the treatment of the patient.

[Modeling of protein spatial structure using tritium planigraphy].

The results of proteins spatial structure modeling using the tritium planigraphy technique are presented. The knowledge of three-dimensional structure of macromolecules is extremely necessary to understand the basic mechanisms of interaction in biological systems and complex technological processes. Known limitations of the X-ray analysis (crystal state) and NMR (molecular weight) make it necessary to seek new approaches to modeling the spatial structure of proteins. Semiempirical tritium planigraphy technique is one of these approaches. The method is based on the bombardment of the object by beam of hot tritium atoms (E(at) > or = 0.3 eV) and a computer simulation experiment. On the example of proteins of the different structural classes we set that by using this integrated approach can be obtained by three-dimensional model of the structure, well consistent with the data of X-ray analysis. An important factor is a sequence search of contacts between secondary structure elements: the best fit model with the native structure is achieved by assembling the elements of a vector in the sequence from the N- to C-terminus of the polypeptide chain.