Improvement of amperometric transducer selectivity using nanosized phenylenediamine films.

In this work, we studied the conditions of deposition of a semipermeable polyphenylenediamine (PPD)-based membrane on amperometric disk platinum electrodes. Restricting an access of interfering substances to the electrode surface, the membrane prevents their impact on the sensor operation. Two methods of membrane deposition by electropolymerization were compared-at varying potential (cyclic voltammetry) and at constant potential. The cyclic voltammetry was shown to be easier in performing and providing better properties of the membrane. The dependence of PPD membrane effectiveness on the number of cyclic voltammograms and phenylenediamine concentration was analyzed. It was shown that the impact of interfering substances (ascorbic acid, dopamine, cysteine, uric acid) on sensor operation could be completely avoided using three cyclic voltammograms in 30 mM phenylenediamine. On the other hand, when working with diluted samples, i.e., at lower concentrations of electroactive substances, it is reasonable to decrease the phenylenediamine concentration to 5 mM, which would result in a higher sensitivity of transducers to hydrogen peroxide due to a thinner PPD layer. The PPD membrane was tested during continuous operation and at 8-day storage and turned out to be efficient in sensor and biosensors.

[Endoscopic transsphenoidal resection of pituitary adenomas invading the cavernous sinus]. / Endoskopicheskoe transsfenoidal'noe udalenie adenom gipofiza, vrastayushchikh v kavernoznyi sinus.

INTRODUCTION: Pituitary adenomas are benign growths that invade the cavernous sinus (CS) in 10-15% of cases. There are different types of microsurgical and endoscopic approaches enabling resection of tumors from the CS cavity that is a relatively small and hard to reach anatomical structure comprising eloquent neurovascular structures. MATERIAL AND METHODS: A study group included 97 patients with pituitary adenomas (PAs) invading the CS. PAs were resected using an endoscopic technique: adenomas were resected from the CS cavity through a standard endoscopic endonasal transsphenoidal approach in 62 cases; a lateral extended transsphenoidal endoscopic approach was used in 35 cases. A control group included patients with PAs spreading into the laterosellar region who were operated on using microsurgical extra-intradural (n=14) and transsphenoidal (n=149) approaches. In the study group, the degree of PA invasion into the CS cavity was determined using the Knosp scale. RESULTS: In the study group, total tumor resection was achieved in 49 (50.5%) cases, subtotal resection in 39 (40.2%) cases, and partial resection in 9 (9.3%) patients. In the case of visual disorders (n=70), vision improvement was achieved in 41.4% of cases. Vision deterioration was detected in 11.4% of cases; no vision changes were in 47.1% of cases. Patients (27.8%) who had not had visual impairments before surgery had no negative changes in vision in the postoperative period. The development/augmentation of oculomotor disorders in the study group occurred in 14 (14.4%) cases. In the study group, hormonal remission of the disease in patients with hormone-active PAs was in 26.7% of cases (n=12). There were no cases of nasal liquorrhea, meningitis, and death in the study group. CONCLUSION: Endoscopic endonasal transsphenoidal resection of PAs invading the CS is a more efficient and safer surgical technique compared to microsurgical techniques (transsphenoidal and extra-intradural approach). The lateral extended transsphenoidal endoscopic approach enables resection of PAs with massive invasion into the CS (Grade III and Grade IV, Knosp scale) and has less postoperative complications compared to the extra-intradural approach (p<0.05).

[The risk-adaptive strategies of Hodgkin's lymphoma therapy].

Using of radiochemotherapy improves short-term and long-term results of treatment in patients with primary Hodgkin's lymphoma (HL) comparing with treatment by chemotherapy alone. The rates of 5-year, 10-year OS and DFS are 88%, 83% and 90%, 86% in case of radiochemotherapy, versus 73%, 66% and 72%, 68% using chemotherapy alone. The 5-year and 10-year OS, DFS estimates in treatment with ABVD are 84% and 83%, 75% and 74%; BEACOPP-baseline - 83% and 82%, 82% and 81% (p<0.05). At the same time ABVD chemotherapy develops less toxicity (p<0.001). The treatment with 6 cycles of ABVD is considered as the most appropriate in primary Hodgkin's lymphoma patients with extranodal lesions. Comparison of complications rate during chemotherapy with MOPP, ABVD, BEACOPP-baseline, BEACOPP-escalated reveals major hematologic toxicity and infectious complications rate in BEACOPP-escalated program (p<0,05). The age ≥45 years, hemoglobin <105g/l, B symptoms, fibrinogen >5g/l, involvement of 3 and more areas of lymph nodes, liver involvement, inguinal lymph nodes are defined by the multiple-factor analysis as adverse prognostic factors of patients with primary Hodgkin's lymphoma (HL) with extranodal lesions (p<0.05). Allocation of group of high risk is proved by correlation between survival and the Prognostic Score (PS). The 5-year and 10-year DFS, OS for patients with PS-0-2 estimates are 88% and 86%, 89% and 83%, for patients with PS-3-4 - 78% and 69%, 80% and 77%, for patients with PS-5-6 - 43% and 42%, 60% and 38% respectively (p<0.001).

Role of molecular-genetic abnormalities in pathogenesis and risk stratification of multiple myeloma.

Over the past decades the studies have greatly improved our understanding of the molecular basis of multiple myeloma (MM) and mechanisms of disease progression. The majority of the most widespread chromosomal aberrations, revealing in MM, has independent predictive value and influence on a choice of optimal treatment. There were observed 190 MM patients in hematologic hospitals of St. Petersburg. Genetic anomalies (GA) were detected at 3l,3% of patients and did not depend on their age. Patients with ISS III had a detectability of GA higher than with ISS II and ISS I (48,°% (24/5°), 2l,2% (7/33) and 27,6% (8/29)). Translocation t(ll;l4) was found in 23,3% (3O/129) patients; dell3q - 20,8% (27/13°); dell7p - at 8,4% (7/83); t(4;l4) - at 6,9% (9/13O), that allowed to stratify patients in groups of risk according to mSMART version l. O and 2. O. Median overall survival (OS) modified mSMART l. O in group of standard risk was 7° months, high risk - 47,l months. Median OS mSMART 2. O in group of standard risk was 7° months, intermediate risk - 47 months, high risk - 45 months. OS did not depend on age, clinical manifestations, treatment and other factors.

[Selective Heating of Membrane-forming Holes in Teflon Film Exposed to Decimeter Waves].

Calculations of heating of membrane-forming holes in Teflon film exposed to decimeter waves were performed. The dependence of the temperature increment in holes on the geometry of holes, electrolyte concentration, and decimeter wave frequency was studied. The kinetics of heating depending on the hole diameter was also obtained. It was concluded that the observed in the experiment effects of the decimeter wave on bilayer lipid membranes resulted from the elevated concentration of decimeter electromagnetic waves in membrane-forming hole that led to selective heating of electrolyte in hole and bilayer lipid membranes.

[The effectiveness of using HyperHAES hypertonic isooncotic plasma solution to achieve stable intracranial hypotension in endoscopic endonasal transsphenoidal adenomectomy as an alternative to the invasive external lumbar drainage].

The structure of surgery of pituitary adenomas has been fundamentally changed over the past decade. The transnasal transsphenoidal approach is currently used to resect more than 95% of adenomas. The wide use of endoscopy has changed the need for perioperative control of intracranial pressure. While controlled intracranial hypertension was previously used during microscopically controlled transnasal surgery to bring the suprasellar capsule and tumor remnants to the field of vision, endoscopically controlled tumor resection implies that controlled intracranial hypotension is required to achieve complete spreading of the suprasellar capsule. External lumbar drains inserted at least for the entire surgery duration are conventionally used to control intracranial pressure. We present the results of the study proving the effectiveness and safety of the HyperHAES hypertonic isooncotic plasma substitute in achieving stable intracranial hypotension according to a large body of clinical data. Our findings give grounds for claiming that the use of the HyperHAES hypertonic isooncotic plasma substitute during the standard adenomectomy allows one to abandon the use of invasive external lumbar drainage, while the surgery quality and risks remain at the same level.

ADAPTIVE MECHANISMS OF THE IMMUNE SYSTEM IN CHILDREN IN FAR NORTH.

This article is devoted to the probleme of modern Pediatrics pathology of the immune system in children with complicated viral infections. The aim of this study was to investigate the immune and cytokine status in children with complicated acute respiratory viral infections. The study included 100 children are often ill respiratory virus infections (more than 8 times per year) from age 0 to 7 years, and 30 children with upper respiratory tract infection; no more than 1 time per year-the control group. The standards of indicators developed by the staff of Immunological laboratory Diagnostic center of the Ministry of health of Republic Sakha (Yakutia ) together with the Institute of health of the Republic Sakha (Yakutia). Statistical calculations made on the basis of applied programs "SAS"and "SPSS"In the analysis of contingency tables (estimates of the correlation of the characteristic and evaluation of significance of differences between groups) used the criterion of 2 (Pearson and likelihood ratio and Fisher's exact test. Comparison of mean values was performed univariate analysis of variance using T-student criterion for assessing the equality of mean F-Fisher test to assess equality of variance. Extreme climatic conditions ofthe far North have an impact on immunological mechanisms. In the analysis of changes ofthe immune status revealed the greatest decline in T-cell level and components of complement in children with complications of viral respiratory infections. In children with complicated respiratory viral infections reduced cellular immunity (CD3+, CD41, CD81, CD+, CD 22+). In children with complicated respiratory viral infections decrease levels ofcytokines (IFN-y FN0-d), indicating about the risk of the formation of complications of respiratory viral infections. As a result of drug therapy of broncho-vaxom marked improvement in immune status and the absence of recurrence of respiratory viral infections within the next 3 months after therapy.

[The role of genetic polymorphisms of interleukins in chronic lymphocytic leukemia in patients of different ages].

Chronic lymphocytic leukemia (CLL) is a multifactorial disease, in which development the important role played the cytokine genes, in particular interleukins. This type of leukemia is more common in the elderly. The purpose of the study was to evaluate the association of genetic polymorphisms of interleukin with the development of chronic lymphocytic leukemia among residents of the Central Chernozem region of Russia. Genotyping of the -889C/T IL-1A, -590C/T IL-4 and VNTR IL-1 Ra was conducted in 206 patients with CLL and 307 individuals of the control group. The study found that the genetic risk factor for the development of CLL is allele -590T IL-4 (OR=-1,45). The development of thrombocytopenia in patients with CLL is associated with genetic variants -889T IL-1A (OR=1,95), -889TT IL-1A (OR=6,2) and IL-1Ra*1 (OR=-2,32).

[Objective assessment of trauma severity in patients with spleen injuries].

The work presents an analysis of condition severity of 139 casualties with isolated and combined spleen injuries on admission to a surgical hospital. The assessment of condition severity was made using the traditional gradation and score scale VPH-SP. The degree of the severity of combined trauma of the spleen was determined by the scales ISS. The investigation showed that the scale ISS and VPH-SP allowed objective measurement of the condition severity of patients with spleen trauma. The score assessment facilitated early detection of the severe category of the patients, determined the diagnostic algorithm and the well-timed medical aid.

[Damage to the cavernous segment of internal carotid artery in transsphenoidal endoscopic removal of pituitary adenomas (report of 4 cases)].

Endoscopic endonasal transsphenoidal approach (EETA) is an effective and relatively safe to remove pituitary adenomas and other sellar region tumors. One of the most serious complications of transsphenoidal surgery is damage to the cavernous segment of the internal carotid artery, which by different authors occurs at 0 to 3.8%. In the period from 2005 to March 2013 in Burdenko neurosurgical institute 3,000 patients with pituitary adenomas were operated by standard endoscopic transsphenoidal approach. Damage to the internal carotid artery (ICA) occurred in 4 patients, which amounted to 0.13%. To all patients with damage of the ICA angiography was performed in which identified one case of occlusion of the ICA and three cases of false aneurysm formation. Three patients underwent endovascular treatment. Damage to the internal carotid artery may be associated with the wrong orientation in the surgical wound, or excessively aggressive manipulations in the cavernous sinus. Damage to the cavernous segment of the ICA during transsphenoidal surgery is a rare but potentially fatal complication. Extremely important is the correct localization of the middle line and ICA using navigation systems and Doppler ultrasound.

[Complex chromosome damages in patients with recurrent acute leukemias after allogeneic hematopoietic stem cell transplantations].

AIM: To study the pattern of complex chromosome damages (CCD) in acute leukemias (AL) and their place in the development of post-transplant recurrences (PTR) of AL. MATERIALS AND METHODS: Cytogenetic and partially molecular biological studies of bone marrow cells were conducted in 10 patients with PTR. Of them, 6 patients were diagnosed as having acute lymphoblastic leukemia (ALL), including T-ALL and Ph-positive ALL in 2 and 4 patients, respectively; and 4 patients had acute non-lymphoblastic leukemia (ANLL), including one case secondarily induced by previous polychemotherapy (PCT) and irradiation. The standard G-band staining technique complemented by multicolor fluorescence in situ hybridization in one of the cases was used. RESULTS: It was shown that CCD had the similar pattern in 4 patients before transplantation and in PTR, progressed in 4 more patients, was absent or unnoticed in the early stage of the disease. The other recurrent chromosomal abnormalities that are worthy of notice are as follows: a) the presence of two Ph chromosomes in the cells of two of the 4 patients with Ph+ ALL; b) the frequent involvement of chromosome pairs 9, 19, 5, and 7 into the numerical and structural rearrangements. CONCLUSION: The important feature of PTR of AL is cellular CCDs, a portion of which is clearly related to previous PCT and may be of pathogenetic value for the development of recurrences.

[Endoscopic endonasal surgery of pituitary adenomas (experience of 1700 operations)].

The current paper analyses results of endoscopic endonasal surgical treatment of 1700 patients with pituitary adenomas in Burdenko Neurosurgical Institute during recent 7 years. We assessed the following parameters: dynamics of basic syndromes (neuroophthalmological, neurological and endocrinological symptoms), degree of resection, frequency and types of postoperative complications, postoperative mortality, recurrence rate etc. The obtained data were compared with results of microsurgical transnasal operations which were formerly performed in our department, as well as with results of leading endoscopic neurosurgeons of the world. In majority of parameters our results are on the same level as the data of most prominent endoscopic neurosurgeons of the world and are significantly better that in the group of patients operated using a microscope.

Charge-driven selective localization of fluorescent nanoparticles in live cells.

Covalent grafting of amino groups onto the carboxylic acid functionalities, naturally covering the surface of fluorescent nanoparticles produced from silicon carbide (SiC NPs), allowed tuning of their surface charge from negative to highly positive. Incubating 3T3-L1 fibroblast cells with differently charged SiC NPs demonstrates the crucial role of the charge in cell fluorescent targeting. Negatively charged SiC NPs concentrate inside the cell nuclei. Close to neutrally charged SiC NPs are present in both cytoplasm and nuclei while positively charged SiC NPs are present only in the cytoplasm and are not able to move inside the nuclei. This effect opens the door for the use of SiC NPs for easy and fast visualization of long-lasting biological processes taking place in the cell cytosol or nucleus as well as providing a new long-term cell imaging tool. Moreover, here we have shown that the interaction between charged NPs and nuclear pore complex plays an essential role in their penetration into the nuclei.

[Frequency dependence of heating of human skin exposed to millimeter waves].

In this paper we studied experimentally the frequency dependence of heating of human skin exposed to millimeter waves. Theoretical modeling of obtained data was performed using the hybrid bio-heat equation. It was found that the skin heating and SAR increased with increasing the exposure frequency. The frequency dependence of heating was entirely resulted from that of reflection from the skin. Unlike temperature, the frequency dependence of the SAR was due to the increased absorption of millimeter wave energy within the thin surface layer of the skin.

Size tuning of luminescent silicon nanoparticles with meso-porous silicon membranes.

Size tuning of silicon (Si) nanoparticles (NPs) with the use of meso-porous silicon (meso-PS) free-standing layers is reported for the first time. Accumulation of Si NPs inside the membrane pores during the filtering process (NP transport through the meso-PS) leads to an auto-filtration effect (called Si-by-Si (SBS) filtration) allowing more efficient size selection of the NPs. General complex fractal shape and surface chemistry of the whole porous network, layer thickness as well as a given initial NP size dispersion determine final size of the NPs in the filtered solution. Moreover, quantum of step-like NP size increasing equal to 0.12 nm was found.

[Problems of using a thermocouple for measurements of skin temperature rise during the exposure to millimeter waves].

The possibility of using thermocouples for the artifact-free measurements of skin temperature during millimeter wave exposure was studied. The distributions of the specific absorption rate (SAR) in the human skin were calculated for different orientations of the thermocouple relative to the E-field of exposure. It was shown that, at the parallel orientation of a thermocouple relative to the E-field, SAR significantly increased at the tip of the thermocouple. This can result in an overheating of the thermocouple. At the perpendicular orientation of a thermocouple, the distortions of the SAR were insignificant. The data obtained confirm that the skin temperature can be measured with a thermocouple during exposure under the condition that the thermocouple is located perpendicular to the E-vector of the electromagnetic field. For the accurate determination of SAR from the rate of the initial temperature rise, it is necessary to fit the temperature kinetics measured with the thermocouple to the solution of the bio-heat transfer equation.

[Postoperative acute pancreatitis after treatment of traumatic spleen lesion].

Results of the surgical treatment of 96 patients with isolated blunt spleen trauma and 43 patients with intraoperative spleen injury were analyzed. Acute postoperative pancreatitis developed in 20 patients (14,4%). Interdependence between the type and extent of the operative spleen treatment and pancreatitis frequency was registered. Of 93 splenectomized patients 18 (19,4%) developed postoperative pancreatitis, and of 46 patients, who had an organ-preserving operation, pancreatitis was registered in only 2 cases (4,3%). Thus, spleen-preserving operations allow to decrease the frequency of postoperative pancreatitis. Method of the reversible spleen mobilization increases the possibilities of the organ-preserving treatment in case of hard-to-reach ruptures.

[Effect of microwaves on bilayer lipid membranes: role of a membrane-forming hole in the Teflon film].

The distributions of specific abcorption rate (SAR) and E-field in a membrane-forming hole of Teflon film and surrounding electrolyte were calculated for 0.9 GHz exposure. It was found that the specific absorption rate in the membrane-forming hole increased greatly with increasing thickness of the Teflon film, and electrolyte concentration and decreasing diameter of the hole. The previously demonstrated significant changes in the conductivity of modified bilayer lipid membranes induced by microwave exposure can be explained by a local increase in specific absorption rate and subsequent elevation of temperature in the membrane-forming hole of the Teflon film.