[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.

[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.

[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).

[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).

[Baker's cysts in patients with gonarthrosis in early stages according to arthrosonography and magnetic resonance tomography]. / Kisty Beikera u bol'nykh gonartrozom na rannikh stadiiakh po dannym artrosonografii i magnitno-rezonansnoi tomografii.

We studied potentialities of MR-tomography (MRT) and arthrosonography (ASG) for diagnosis of Baker's cysts in patients with early gonarthrosis (GA) regarding X-ray stage and presence of reactive synovitis. A total of 50 GA patients were examined. 100 knee joints were examined by x-ray and ASG, 79 ones by MRT (ALOKA-2200 ultrasound unit, 7.5 MHz sensor; 1.5 T Eclipse tomography, 1.5 T, Marconi, Picker). The ultrasound sensor was applied to the anterior and posterior surface of the knee joints in maximally extended joint in a dorsal position. MRT was made in a partially flexed fixed joint. It was found that the percentage of Baker's cyst (BC) diagnosis by MRT and ASG varies insignificantly (35.4 and 30.4%, respectively). Combined use of MRT and ASG detected the cysts more frequently in GA stage II by Kellgren (60.7% by MRT and 62.5% by ASG, p > 0.05). Combination of subclinical synovitis and the cysts was detected by MRT and sonography in 66.6 and 60% of the joints. Both MRT and ASG revealed no correlations between the frequency of BC and clinical synovitis. Both methods more frequently detected popliteal cysts and BC in subclinical synovitis.

[Determination and analysis of the primary structure of a genomic sequence adjacent to the 3'-end of the human tissue plasminogen activator gene]. / Opredelenie i analiz pervichnoi struktury genomnoi posledovatel'nosti, prilegaiushchei k 3'-kontsu gena tkanevogo aktivatora plazminogena cheloveka.

Primary structure was determined for the recently cloned f1/BglII-fragment [19] containing 2102 b.p. of the human tissue plasminogen activator (tPA) gene 3' end and adjacent DNA region. Computer analysis has revealed an Alu-repeat 820 b.p. downstream the tPA gene; the sequence proved to have a considerable homology (86-88%) with the Alus from the 3'-untranslated regions (3'UTRs) of cytochrome P-450, lysozyme and p53 protein human mRNAs. The same homology was estimated for this Alu in reversed orientation and Alus from the 3'UTRs of some other human mRNAs. In contrast, the homology between this 3' end tPA gene flanking Alu-repeat and other Alus dispersed throughout the gene introns either direct or reversed, was less than 70%. The polyadenylation signal AATAAA downstream the Alu and two nearby signals CACAG and GTGTT resembling consensus sequences CACAG and YGTGTTYY, respectively, were also detected. The two latter motifs located close to the 3' ends in most mammalian genes are likely to regulate mature mRNA formation. The comparison of the sequenced spaser flank adjacent to the tPA gene with short homologous sequence from the same genomic region primary structure reported previously has revealed discrepancies (substitutions, deletions or insertions) in 21 nucleotide positions. The nucleotide sequence of E. coli uvrB gene fragment (980 b.p.) is also reported. This E. coli gene fragment was cloned accidentally within the f1/BglII-fragment being an artifact of the host-vector system used.

[A beta-casein gene fragment is located in region 1p3 of human chromosome 1]. / Fragment beta-kazeinovogo gena lokalizovan v oblasti 1p3 pervoi khromosomy cheloveka.

Analysis of the nucleotide sequence of a cloned fragment of the human beta-casein gene was performed. A conserved DNA locus, present with a varying degree of degeneracy in introns of [beta]-casein genes of several species and in the intron of an oncogene of the sarc family, was revealed. It was located in region 1p31-32 by means of in situ hybridization. A clearly visible additional hybridization site was observed in region 1p36. The data obtained are discussed in the light of available information on several oncogenes that are located in region 1p3. A relation was found between this region and the occurrence of some cancers, including breast cancer.

[Isolation and characteristics of DNA fragments for the region of the tissue plasminogen activator genes and areas adjacent to it in the human genome]. / Vydelenie i kharakteristika fragmentov DNK oblasti gena tkanevogo aktivatora plazminogena i prilegaiushchikh k nemy uchastkov genoma cheloveka.

Fragments overlapping the tPA gene and its 5'- and 3'-flanking regions were isolated from human liver DNA library cloned in lambda Charon4A vector. A BglII fragment comprising the 3' end and the adjacent genomic region (total length 3.7 kb) was subcloned in plasmid pUC19 and its restriction map was determined. The nucleotide sequence of the 5' region of this fragment was compared with the 3' end region of the tPA gene and the corresponding regions of five published variants of tPA mRNA cDNA from different tissues; discrepancies in seven positions were revealed, which might be caused by intragenomic polymorphism.

[Recombinant murine cell lines, transformed by various vectors based on bovine type 1 papillomavirus and expressing human tissue plasminogen activator. II. Analysis of cell lines, producing recombinant tissue plasminogen activator]. / Rekombinantnye linii kletok myshi, transformirovannye raslichnymi vektorami na osnove bych'ego papillomavirusa tipa 1 i ékspressiruiushchie tkanevoi aktivator plazminogena cheloveka. II. Analiz kletochnykh linii, produtsiruiushchikh rekombinantnyi tkanevoi aktivator plazminogena.

We have characterized a number of recombinant cell lines established with BPV1 and Lx1 (containing duplication of LCR-E6-E7 sequence) vectors on the basis of C127 cells. It had been shown that Lx1 based vectors possess the higher number of intracellular copies than analogous vectors on the basis of wtBPV, and most part of them is integrated into the host genome. Using various concentrations of heavy metal salts we have developed the optimized procedure for induction of recombinant tPA synthesis which is controlled by the mouse MT1 promoter. A 8-fold increase of rtPA concentration was reached in the course of induction. It had been shown that native and non-glucosylated forms of recombinant and human tPA are identical in their properties.

[Computerized tomography in the diagnosis of organic brain lesions in patients with schizophrenia]. / Komp'iuternaia tomografiia v diagnostike organicheskoi patologii golovnogo mozga u bol'nykh shizofreniei.

The authors retrospectively analyse CT data obtained in examinations of 1745 patients divided into three groups. Of these, 832 were male and 913 female patients. Group 1 consisted of 721 patients with schizophrenia, group 2 (reference) consisted of 855 mentally normal subjects directed to computer tomographic examination with suspected organic involvement of the brain, and group 3 (control) consisted of 169 mentally and neurologically normal subjects. On the whole the incidence of various organic brain lesions was 8% in group 1, 41.5% in group 2, and 6.5% in control group, whatever the of the examinees or any other factors. Vascular diseases of the nervous system predominated in group 2 as against group 1, being 3.5 times more incident. No intracranial tumors were detected in controls; in schizophrenics computer tomographic signs of volumic brain lesions were detected in 1.5% of cases, being diagnosed more than 10 times more frequently than in group 2 patients.

[The existence of the ribonucleoprotein branching enzyme in rabbit skeletal muscle and ribozyme corresponding to it]. / K voprosu o sushchestvovanii v skeletnykh myshtsakh krolika vetviashchego fermenta ribonukleoproteidnoi prirody i sootvetstvuiushchego ribozima.

Amylose isomerase (AI) preparations were isolated from rabbit muscles after Petrova et al., as well as by the additional fractionation steps. Their homogeneity, enzymatic activity and RNA, isolated from those preparations, were characterized. AI preparations, as described by Petrova et al., proved to be heterogeneous in respect to the protein and RNA; by using additional fractionation methods RNA and protein have been separated from each other, which proves that a homogeneous stable ribonucleoprotein complex, exerting AI activity, does not exist. It was shown by three independent methods that AI preparations isolated after Petrova do not display branching, but have amylolytic activity. RNA, isolated along with the AI preparations, proved to be mainly total tRNA degraded to different degrees. No RNA corresponding to the previously sequenced 2.5S RNA could be detected in these preparations. RNA preparations do not manifest neither branching, nor amylolytic activity. Our data prove that there is no ribozyme, whose existence has been suggested previously.

[Recombinant murine cell lines transformed by various vectors based on bovine papillomavirus type 1 and expressing human tissue plasminogen activator]. / Rekombinantnye linii kletok myshi, transformirovannye razlichnymi vektorami na osnove bych'ego papillomavirusa tipa 1 i ékspressiruiushchie tkanevoi aktivator plazminogena cheloveka.

We have constructed a number of vectors which include transcriptional unit of human tPA cDNA and 100% BPV-1 DNA or 100% Lx DNA (mutant BPV variant with tandem duplication of LCR-E6-E7 region). Additional HSV-1 Tk-promoter was inserted in the flanks of viral DNAa in a set of constructions. A number of recombinant cell lines have been established by means of transformation using the constructed vectors. The increased focus formation activity and the improved vector properties were demonstrated for vector construction which included Lx DNA with additional Tk promoter for activation of early viral transcription. The possibilities of BPV-based vectors design are discussed.