[Surgical treatment of brain tumors adjacent to corticospinal tract in children]. / Aktual'nye voprosy khirurgicheskogo lecheniya opukholei golovnogo mozga, prilegayushchikh k kortikospinal'nomu traktu u detei.

An urgent problem in modern neurosurgery is resection of brain tumors adjacent to corticospinal tract (CST) due to high risk of its damage and subsequent disability. The main methods for prevention of intraoperative damage to CST are preoperative MR tractography and intraoperative electrophysiological monitoring. Both methods are used in pediatric neurosurgery. We reviewed the PubMed database since 2000 using the following keywords: «tumors of the hemispheres in children¼, «corticospinal tract¼, «MR tractography¼, «intraoperative electrophysiological monitoring¼. We present available literature data on preoperative MR tractography and intraoperative electrophysiological monitoring in children with supratentorial tumors near CST. Algorithm of intraoperative electrophysiological monitoring is often missing or insufficiently described. MR tractography is usually presented in case reports. Researchers do not compare the effectiveness of MR tractography and intraoperative electrophysiological monitoring. In case of MR tractography, a limitation is impossible CST reconstruction in children 2-3 years old. This may be due to unformed pyramidal system in these children. CONCLUSION: Preoperative MR tractography and intraoperative electrophysiological monitoring are valid methods for assessment of CST. Optimal research parameters in children require careful study that will allow objective planning of each stage of preoperative management and increase resection quality for gliomas near CST in children without neurological deterioration.

[Intraoperative visual evoked potential recording in occipital tumor surgery]. / Udalenie opukholei zatylochnoi doli s primeneniem intraoperatsionnoi registratsii korkovykh zritel'nykh vyzvannykh potentsialov.

Currently, visual field defects are considered as an inevitable consequence of occipital lobe surgery. However, recent advances in neuroimaging techniques, such as diffusion tensor tractography allowing better visualization of optic radiation and its relationship with occipital lobe tumors, as well as intraoperative monitoring of cortical visual evoked potentials (cVEPs) can contribute to correct planning of surgery and minimizing the risk of visual field defects after surgery. OBJECTIVE: To evaluate the effectiveness of intraoperative monitoring of cVEP in patients with occipital lobe tumors. MATERIAL AND METHODS: Ten patients with occipital lobe tumors have undergone surgery with neurophysiological monitoring since 2020. Mean age of patients was 57 years. There were 6 women and 4 men. In 7 patients, neoplasms were located in the right hemisphere, in 3 patients - in the left hemisphere. According to preoperative automatic perimetry data, 7 patients had various visual field defects, and other ones had intact visual fields. All patients underwent pre- and postoperative MRI for visualization of optic radiation, its relationship with tumor and control of resection quality. Intraoperative monitoring of cVEPs was performed in all patients. RESULTS: Biopsy verified glioblastoma in 5 cases, metastasis of adenocarcinoma - 2 cases, diffuse glioma - 1 case, ganglioglioma - 1 case, CNS lymphoma - 1 case. Postoperative MRI confirmed total or subtotal resection of tumor in all cases. Enlargement of visual fields occurred in 3 patients after surgery. Two ones had deterioration and/or new homonymous defect. No changes of visual fields was observed in other cases. Analysis of visual field defects after surgery found no correlation with functional state of visual tract according to fractional anisotropy before and after surgery. CONCLUSION: MR tractography of optic radiation and intraoperative monitoring of cVEP allow choosing the safest approach for resection of occipital tumor and minimizing the risk of damage to visual cortex and optic radiation fibers. In most cases, postoperative visual functions do not worsen after intraoperative mapping of visual cortex and determining the safest trajectory for resection of occipital lobe tumors. Moreover, improvement is observed in some cases.

[Surgical treatment of hemispheric and subcortical gliomas adjacent to corticospinal tract in children using MR tractography and intraoperative electrophysiological monitoring]. / Opyt khirurgicheskogo lecheniya gliom bol'shikh polusharii i podkorkovykh struktur golovnogo mozga, prilegayushchikh k kortikospinal'nomu traktu, u detei s ispol'zovaniem MR-traktografii i intraoperatsionnogo elektrofiziologicheskogo monitoringa.

Difficult total resection of supratentorial gliomas adjacent to the corticospinal tract (CST) is due to the high risk of its injury and disability of patients. The main methods for preventing intraoperative CST damage are preoperative MR tractography and intraoperative electrophysiological monitoring. The problem of total resection of gliomas adjacent to the CST with preservation of high functional status is difficult due to immaturity and plasticity of brain structures in children. Moreover, the advantages of MR tractography combined with intraoperative monitoring have not been described. The authors present surgical treatment of supratentorial gliomas adjacent to the CST at different anatomical levels. Patients underwent preoperative and postoperative MR tractography and intraoperative electrophysiological monitoring. MR tractography provided preoperative data on CST lesion. Intraoperative monitoring made it possible to identify and preserve CST in the depth of surgical wound. MR tractography and intraoperative electrophysiological monitoring increase resection quality in patients with hemispheric and subcortical gliomas without postoperative functional deterioration.

Predictive value of laboratory markers in the development of cardiac events in patients with stable coronary artery disease after elective endovascular revascularization.

Aim      To reveal a relationship between preprocedural laboratory data and adverse cardiac outcomes (CO) in patients with stable ischemic heart disease (IHD) following elective endovascular revascularization (ER).Material and methods  This study included 225 patients with IHD admitted for treatment to the Research Institute of Cardiology of the Tomsk National Research Medical Center. The study included patients with documented IHD and hemodynamically significant coronary stenoses requiring elective ER. Patients were divided into groups based on the presence of complications: group 1, 98 patients with adverse CO and group 2, 127 patients without adverse CO. Besides evaluation of complaints, history, and objective status, general clinical and biochemical tests were performed for all patients. Concentration of glycated hemoglobin (НbА1с) was measured by immunoturbidimetry (DiaSys Diagnostic Systems). Serum concentrations of insulin, interleukin-6 (IL-6), endothelin 1 (ET-1), and homocysteine were measured by enzyme immunoassay. Blood lipid profile was determined by enzymatic colorimetry (DiaSys). Content of non-high-density lipoprotein (non-HDL) cholesterol (CS) was calculated as: CS - HDL CS. Insulin resistance (IR) was assessed by the HOMА-IR index. IR was diagnosed at the index of 2.77. Statistical analyses were performed with Statistica 10.0 and Medcalc 19.2.6 software.Results A one-way regression analysis identified predictors for adverse CO following ER. The most significant predictors were fibrinogen (odds ratio (OR), 1.430; 95 % confidence interval (CI), 1.027-1.990), HbA1c (OR 1.825; 95 % CI, 1.283-2.598), homocysteine (OR, 1.555; 95 % CI, 1.348-1.794), ET-1 (OR, 94.408; 95 % CI, 16.762-531.720), triglycerides (TG)/glucose ratio (OR 1.815; 95 % CI, 1.155-2.853). Based on selected factors, logistic regression models were constructed. However, not all models had a high prognostic power. Only concentrations of ET-1 and homocysteine showed a high prognostic capability in respect of the adverse outcome (88.3 and 85.7 %, respectively).Conclusion      For patients with IHD, the prognostic capability of ET-1 and homocysteine with respect of the risk for adverse CO following ER was the highest compared to other markers. The results of the study are completely consistent with data of literature and can be successfully used in clinical practice for optimizing the medical care of patients after elective ER.

Refractory and Resistant Hypertension in Patients with Type 2 Diabetes Mellitus: Different Response to Renal Denervation.

Aim      To compare the antihypertensive effectivity of renal denervation in patients with diabetes mellitus (DM) and associated refractory arterial hypertension (rfAH) (treated with 5 or more classes of antihypertensive drugs, including a thiazide diuretic and a mineralocorticoid receptor antagonist) and uncontrolled resistant AH (ucAH) (treated with 3-4 drugs).Material and methods  This interventional study with renal denervation included 18 DM patients with rfAH and 40 DM patients with ucAH; 16 and 36 of them, respectively, completed the study in 6 months. At baseline, patients were sex- and age-matched. Study methods included measurement of office blood pressure (BP; systolic/diastolic BP, SBP/DBP); outpatient BP monitoring; evaluation of kidney function (estimated glomerular filtration rate by the CKD-EPI formula); diurnal diuresis volume; diurnal urinary excretion of albumin, potassium and sodium; diurnal excretion of metanephrines and normetanephrines; and plasma levels of glucose and glycated hemoglobin, aldosterone, and active renin. Patients were instructed about maintaining compliance with their antihypertensive and hypoglycemic therapy throughout the study.Results At baseline, patients of both groups were comparable by BP and major clinical indexes, except for higher values of nocturnal SBP variability (p<0.05) in patients with rfAH. At 6 months following renal denervation, both groups displayed significant decreases in office and average daily SBP and also in the "load" with increased mean diurnal SBP. However, the decrease in average daily SBP was almost 4 times greater in the rfAH group than in the ucAH group ( -19.9 and -5.1 mm Hg, respectively, р=0.02). Moreover, 81 % of patients in the rfAH group responded to the intervention (average daily SBP decrease ≥10 mm Hg) while the number of responders in the ucAH group was considerably smaller (42 %; p=0.02). In patients with rfAH, renal denervation was associated with a significant decrease in pulse BP and nocturnal SBP variability and with the increase in diurnal diuresis. No other alterations were noted in laboratory test results in either group.Conclusion      DM patients with rfAH may be the best candidates for the procedure of renal denervation.

[Occipital gliomas. Case report and literature review]. / Intraoperatsionnaya registratsiya korkovykh zritel'nykh vyzvannykh potentsialov pri udalenii gliomy zatylochnoi doli. Klinicheskoe nablyudenie i obzor literatury.

The authors report intraoperative mapping with cortical visual evoked potentials during occipital tumor resection. This approach was valuable to reduce the risk of visual cortex and visual pathways damage and, accordingly, the likelihood of postoperative visual impairment. The peculiarity of this case is registration of clear cortical visual evoked potentials in various positions before and after tumor resection. Intraoperative monitoring was valuable to avoid damage to visual cortex and visual pathways during tumor resection. There was no postoperative visual deterioration. Moreover, we observed partial recovery of visual fields after resection of occipital malignant tumor.

[Modern standards for magnetic resonance imaging of the brain tumors]. / Sovremennye standarty MRT-diagnostiki opukholevykh porazhenii golovnogo mozga.

Neuroimaging is essential in survey of patients with brain tumors. An important objectives of neuroimaging are highly reliable non-invasive diagnosis, treatment planning and evaluation of treatment outcomes. Magnetic resonance imaging (MRI) is one of the modern neuroimaging methods. This technique ensures analysis of structural cerebral changes, vascular and metabolic characteristics of brain tumors. It is necessary to standardize imaging parameters and unify protocols and methods considering a widespread use of MRI for brain tumors. In our practice, we use our own experience, world literature data and evidence-based international guidelines on the diagnosis of various brain diseases. The purpose of this review is to study the modern principles of magnetic resonance imaging in adults with brain tumors in neurosurgical practice.

Two-Stage Revascularization in Patients with Acute Myocardial Infarction and Massive Coronary Thrombosis.

AIM: to investigate safety and angiographic efficacy of two-stage revascularization with percutaneous coronary intervention (PCI) with stenting delayed by one day in patients with acute myocardial infarction (MI) and massive coronary thrombosis. MATERIALS AND METHODS: We included in this study 12 patients with massive infarct related coronary artery thrombus which length was greater than thrice the vessel diameter in the presence of TIMI grade II-III blood flow as detected by coronary angiography (CAG). The emergency PCI was not performed, and conservative antithrombotic therapy continued for 24 hours. After this day, CAG was repeated. RESULTS: Repeat CAG in all patients showed thrombus regression which visually appeared as complete lysis in 8, and partial lysis - in 4 patients. Stenting of residual stenosis was performed in 11 patients without complications. In 1 patient residual stenosis was considered insignificant (<50 %) therefore stenting was not performed. No-reflowphenomenon and recurrent MI were not observed. CONCLUSION: These data suggest that in patients with massive coronary artery thrombosis conservative antithrombotic therapy for 24 hours followed by repeated CAG and, if required, by stenting of residual stenosis, is safe treatment tactics that might reduce the risk of the no-reflow phenomenon.

[Non-contrast ASL perfusion in preoperative diagnosis of supratentorial gliomas]. / Beskontrastnaia ASL-perfuziia v predoperatsionnoi diagnostike supratentorial'nykh gliom.

The purpose of this study was to investigate the potential of pseudocontinuous arterial spin labeling perfusion (pCASL) in assessing the degree of malignancy of brain gliomas at the preoperative stage. MATERIAL AND METHODS: The study included 126 patients aged 12-75 years with supratentorial gliomas of different malignancy (35 low-grade gliomas and 91 high-grade gliomas). The maximum tumor blood flow (TBF) was measured, and the normalized tumor blood flow (nTBF) was calculated relative to the intact semiovale white matter of the contralateral hemisphere. The TBF and nTBF indicators differed significantly between low-grade and high-grade glioma groups (p<0.001). When using TBF and nTBF in the differential diagnosis of low-grade and high-grade gliomas, the area under the ROC curve was 0.96 in both cases. Our findings suggest that 3D pCASL perfusion is an effective technique for preoperative differential diagnosis of low-grade and high-grade gliomas. The study was supported by the Russian Foundation for Basic Research (grant #18-315-00384).

Fabrication and characterization of gold-polymer nanocomposite plasmonic nanoarrays in a porous alumina template.

A facile, cost-effective, and manufacturable method to produce gold-polymer nanocomposite plasmonic nanorod arrays in high-aspect-ratio nanoporous alumina templates is reported, where the formation of gold nanoparticles and the polymerization of a photosensitive polymer by ultraviolet light are simultaneously performed. Transverse mode coupling within a two-dimensional array of the nanocomposite rods results in a progression of resonant modes in the visible and infrared spectral regions when illuminated at normal incidence, a phenomenon previously observed in nanoarrays of solid gold rods in an alumina template. Finite element full-wave analysis in a three-dimensional computational domain confirms our hypothesis that nanoparticles, arranged in a columnar structure, will show a response similar to that of solid gold rods. These studies demonstrate a new simple method of plasmonic nanoarray fabrication, apparently obviating the need for a cumbersome electrochemical process to grow nanoarrays.

[The influence of 24-epibrassidinole on the hormone status of wheat plants under sodium chloride].

We studied the influence of the preconditioning of wheat germ (Triticum aestivum L.) with 0.4 microM 24-epibrassidinole (EB) on the growth and hormone status of plants under the influence of 2% NaCl. The preconditioning with EB promoted the lowering of the extent of the damaging influence of pickling on the growth of germs. The important contribution to the realization of the protective action of EB in the preconditioning of plants is probably that of its ability to lower the level of stress-induced abscisic acid accumulation and the decrease in the content of indole-acetic acid. At the same time, the cytokinin concentration in plants preconditioned with EB under pickling was practically the same as in plants without stress. This fact combined with data about the ability of EB to induce the increase in cytokinin content in wheat, obtained before, allowed us to assume that the protective action of EB on plants is connected, first of all, with the prevention of the increase in level of hormones of cytokinin nature under pickling.

Phase-sensitive time-modulated surface plasmon resonance polarimetry for wide dynamic range biosensing.

A novel polarimetry scheme is proposed to improve the performance of phase-sensitive Surface Plasmon Resonance (SPR) biosensors. The scheme uses s-polarized light, not affected by SPR, as a reference beam, while information on the phase of the p-polarized component is obtained from an analysis of phase-polarization state of light of mixed polarization. We utilize temporal modulation of the beam reflected under SPR by a photo-elastic modulator and show that, under certain birefringent geometry, the signals at the 2nd and 3rd harmonics of modulated frequency can provide ultra-sensitive phase-based response to changes of the refractive index (thickness) of thin films on gold. We also show that the proposed configuration significantly improves detection limit compared to conventional intensity-sensitive SPR, yet enables to maintain wide dynamic range of measurements, which is normally difficult with phase-sensitive SPR schemes. Biosensing applications of the proposed scheme are illustrated in a biological model reaction of avidin - biotin binding on gold.

[The role of neurovisualization methods in diagnosis and verification of vertigo etiology].

Roentgen computed tomography (RCT) and MR-imaging (MRI) were used in investigation of vertigo etiology and affection of the cochleovestibular analyzer in 130 patients aged 28 to 74 years with recurrent systemic rotatory vertigo or its other symptoms. All the patients have undergone comprehensive otoneurological examination, RCT and MRI which showed that peripheral cochleovestibular syndromes (PCVS) caused by arterial hypertension (AH), atherosclerosis (AS), vascular dystonia (VD) are rarely characterized by focal alterations in the brain. PCVS comparison with blood flow in the vertebral arteries (VA) detected most frequently anomalies and asymmetries of the diameters. MR-angiography plays an important role in verification of pathology of intracranial VA. In central cochleovestibular syndrome (CCVS) with AH, AS, VD, principal pathological changes were registered in the brain trunk and cerebellum by MRI. Vestibulometry and otoneurological method detect not only vascular cochleovestibular peripheral and central syndromes but also to make differential diagnosis. RCT and MRI verify cochleovestibular syndromes in patients with multiple encephalomyelitis, VIII nerve neurinoma and tumors of the posterior cranial fossa.

[Vertigo and a role of neurovisual methods in it etiology and diagnosis].

Investigation of vestibular system using a standard method of electro-nystagmography in complex otoneurologic examination does not provide enough information on the etiology of vestibular analyzer lesion, location and diffusion of the pathological process. Neurovisual methods, in particular MRI and CT, have demonstrated high diagnostic validity in such pathological states as tumors of pons cerebellum and posterior focca; infarctions in the stem and cerebellum regions. The study revealed a role of MRI and CT in etiology of vertigo and lesions of cochleovestibular analyzer. One hundred thirty patients aged 28-74 years with recurrent attacks of systemic rotary vertigo and other its appearances have been examined. In 14 (11%) patients such an attack was accompanied by loss of consciousness, falls, double-vision and other neurological symptoms. All the patients underwent otoneurological examination, computer electronystagmography, auditory evoked potentials registration, CT and MRI. It is shown that peripheral cochleovestibular syndromes caused by arterial hypertension, atherosclerosis and autonomic vascular dystonia are rarely characterized by focal cerebral changes (11 patients by CT data and 17 by MRI).

[Mechanisms of protective action of wheat germ agglutinin on cell growth in wheat seedling roots under salinity]. / Mekhanizmy zashchitnogo vliianiia aggliutinina zarodysha pshenitsy na rost kletok kornei prorostkov pshenitsy pri zasolenii.

Effects of 20 nM wheat germ agglutinin (WGA) on relative growth rate, mitotic index (MI) and the cell area in the root extension zone were investigated in seedling of Triticum aestivum L. under the influence of 2% NaCl. It was elucidated that pretreatment of wheat seedling with WGA prevented a salinity induced inhibition of root cell growth, and accelerated the restoration of cell growth after stress removal. The protective WGA effect on root cell growth may be due, presumably, to reorganization of phytohormone balance caused by WGA treatment, which could lead to accumulation of LAA and decrease in the ABA level.

[Wheat germ agglutinin participates in regulation of cell division in apical root meristem of wheat seedlings]. / Uchastie aggliutinina zarodysha pshenitsy v reguliatsii deleniia kletok apikal'noi meristemy kornei prorostkov.

A study was made of cell division activity and hormonal status in roots of 4 day old wheat seedling treated with wheat germ agglutinin (WGA). The revealed stimulating effect of WGA on mitotic index (MI) and cell area in root extension zone was specific for this lectin, because gliadin, taken as a control protein, caused no changes in growth parameters. Phytolectins (phytohemagglutinin and concanavalin A) possessing properties of mitogens rendered no such essential influence on cell growth of wheat. Immunoassay has shown that WGA-treatment leads to accumulation of auxins and cytokinins in roots. This suggest participation of WGA in regulation of MI of meristem cells in roots of seedlings during their interaction with phytohormones.

Doppler effect in resonant photoemission from SF6: correlation between Doppler profile and Auger emission anisotropy.

Fragmentation of the SF6 molecule upon F 1s excitation has been studied by resonant photoemission. The F atomiclike Auger line exhibits the characteristic Doppler profile that depends on the direction of the photoelectron momentum relative to the polarization vector of the radiation as well as on the photon energy. The measured Doppler profiles are analyzed by the model simulation that takes account of the anisotropy of the Auger emission in the molecular frame. The Auger anisotropy extracted from the data decreases with an increase in the F-SF5 internuclear distance.