[Surgical anatomy of the peri-insular association tracts. Part I.The superior longitudinal fascicle system]. / Khirurgicheskaya anatomiya periinsulyarnykh assotsiativnykh provodyashchikh putei. Chast' I. Sistema verkhnego prodol'nogo puchka.

AIM: To study the peri-insular association tract anatomy and define the permissible anatomical boundaries for resection of glial insular tumors with allowance for the surgical anatomy of the peri-insular association tracts. MATERIAL AND METHODS: In an anatomic study of the superior longitudinal fascicle system (SLF I, SLF II, SLF III, arcuate fascicle), we used 12 anatomical specimens (6 left and 6 right hemispheres) prepared according to the Klingler's fiber dissection technique. To confirm the dissection data, we used MR tractography (HARDI-CSD-tractography) of the conduction tracts, which was performed in two healthy volunteers. RESULTS: Except the SLF I (identified in 7 hemispheres by fiber dissection), all fascicles of the SLF system were found in all investigated hemispheres by both fiber dissection and MR tractography. The transcortical approach to the insula through the frontal and (or) parietal operculum is associated with a significant risk of transverse transection of the SLF III fibers passing in the frontal and parietal opercula. The most optimal area for the transcortical approach to the insula is the anterior third of the superior temporal gyrus that lacks important association tracts and, consequently, a risk of their injury. The superior peri-insular sulcus is an intraoperative landmark for the transsylvian approach, which enables identification of the SLF II and arcuate fascicle in the surgical wound. CONCLUSION: Detailed knowledge of the peri-insular association tract anatomy is the prerequisite for neurosurgery in the insular region. Our findings facilitate correct identification of both the site for cerebral operculum dissection upon the transcortical approach and the intraoperative landmarks for locating the association tracts in the surgical wound upon the transsylvian approach to the insula.

[Malignant B-сell lymphoma of the anterior visual pathway].

This work was aimed at studying the optimal diagnosis methods and features of clinical signs of malignant B-cell lymphoma of the anterior visual pathways and choosing the most reasonable treatment method. Six immunocompetent patients with lymphomas in the chiasm-sellar region were examined. The outcomes of high-dose methothrexate chemotherapy and radiotherapy in these patients are analyzed.

[Intraparenchymal brainstem schwannomas: report of three cases and literature review]. / Intraparenkhimatoznye shvannomy stvola mozga: opisanie trekh sluchaev i obzor literatury.

We report three patients with intraparenchymal brainstem schwannomas that were confirmed by surgery and pathological examination: tumors originated from the midbrain parenchyma, the dorsal aspect of the pontomedullary junction and the medulla oblongata respectively. Two of the presented patients differed in age of disease presentation which may reflect different mechanisms of tumor development according to the current views on origin of intraparenchymal schwannomas. One of the cases illustrates treatment of non-communicating hydrocephalus associated with ventricular tumors by preventive stenting of the cerebrospinal fluid pathways.

[Methods of intraoperative control in resection of intraparenchymal brain tumors].

Primary CNS tumors represent 1.4% of all malignant neoplasias and 2.4% of total oncological mortality. The principal goal of tumor resection is maximally possible radical removal with minimal injury of normal brain tissue. This is due to correlation between intraoperative trauma of the brain and postoperative neurological deficit and quality of life. Recently intraoperative ultrasonic and fluorescent methods of guidance have been widely introduced in neurosurgical practice. In conditions of altered anatomy ultrasonographic guidance is intended to optimize approach to intracerebral tumors considering eloquent areas and main vessels. This allows decrease of neurological deficit in the postoperative period. Fluorescent guidance provides possibility of visual differentiation of tumor and normal tissue thus defining the borderline. Combination of these two techniques may lead to more radical resection of tumors and minimize injury of normal brain. We operated 70 patients with primary and metastatic intraparenchymal brain tumors. Intraoperative ultrasonographic guidance was applied in 58 cases, fluorescent guidance--in 21, both methods--in 9.

Micro-Raman spectra of ugrandite garnet.

The natural garnets from chromite ores associated with pegmatoid pyroxenites of Sangalyk area (Uchaly ore district, southern Urals, Russia) were studied by means of micro-Raman spectroscopy. The compositions of these garnets were close to ugrandite, an isomorphous intermediate group of uvarovite-grossularite-andradite, X(3)Y(2)(SiO(4))(3), X = Ca(2+), Y = Al(3+), Fe(3+), Cr(3+), according to Raman spectra and X-ray microprobe analyses. An assignment of most of the observed bands in visible and near infrared Raman spectra is reported.

Characteristics of cellular proliferation in the developing human retina.

The expression of proliferation-associated proteins Ki67 and PCNA was studied in the retinal rudiments of human embryos at 5-8 weeks of development; studies also addressed the numbers of nucleoli in the nuclei of neuroepithelial cells (with consideration of their distances to the apical surface) and DNA-synthesizing cells after transient (20 min) in vitro incubation in serum-free medium containing BrdU. The retinal rudiment of embryos at five weeks of development had neuroepithelium of the typical structure. BrdU-positive nuclei and nuclei with small numbers of nucleoli were located in the basal part of the ventricular zone. However, this organization was disrupted during the initial period of formation of the inner nuclear layer (six weeks). At this time, DNA-synthesizing cells were found even at the apical surface. Retinal rudiments of embryos at 6-7 weeks of development contained an additional area of cell proliferation in the Chievitz layer and the inner nuclear layer. In eight-week embryos, dividing cells were located in the outer nuclear layer, which again acquired the organization typical of neuroepithelium.

[Characteristics of the cell proliferation in the developing human retina]. / Osobennosti kletochnoi proliferatsii v razvivaiushcheisia kletchatke cheloveka.

The retinal primordia were studied in human embryos at developmental weeks 5-8 to examine the expression of proliferation-associated proteins (Ki67 and PCNA), the number of nucleoli in the nuclei of neuroepithelial cells (in respect to their distance to the apical surface) and the distribution of DNA-synthesizing cells after a short-term (20 min) incubation in vitro in serum-free medium containing BrdU. In 5-week embryos, retinal primordium contains the neuroepithelium with a typical structure. BrdU-positive nuclei and nuclei with small number of nucleoli were found in the basal portion of the ventricular zone. However, this organization was disturbed in the initial period of the formation of inner nuclear layer (week 6). At this stage DNA-synthesizing cells were seen even at the apical surface. In retinal primordia of embryos at weeks 6-7 there appeared an additional area of cell proliferation in the Chievitz layer and in the inner nuclear layer. In embryos at week 8 the dividing cells were concentrated in the outer nuclear layer, which has regained the organization, typical for a neuroepithelium.

[Reactive invagination of the neuroepithelium in anlages of the human neocortex, tectum of the midbrain, and the retina at various stages of development]. / Invaginatsionnaia reaktsiia neiroepiteliia v zakladkakh neokorteksa, kryshi srednego mozga i setchatki glaza cheloveka na raznykh stadiiakh razvitiia.

Intensity of invagination of neuroepithelium of neocortex of human embryonal anlages of neocortex, tectum of the midbrain and retina was studied as a response to mechanic damage of ventricular zone induced in the course of preparation of the anlages to explanation. It was shown that no invagination formed in 24 hrs of the explantation. In neocortical anlage intensity of invagination was meximal in 6.5 wks embryo. In tectum invagination intensity of th explants lowered gradually from wk 5 to wk 7.

[The reaction of the rat thymus to xenotransplantation and immunosuppression]. / Reaktsiia timusa krysy na ksenotransplantatsiiu i immunosupressiiu.

To the complex action of human embryonal neocortex transplanted into the eye anterior chamber and cyclosporin A injected daily to prevent graft rejection rat thymus reacts by accidental involution, layer inversion and vascular disturbances (without hematoma formation). After 3 wks reparative period sets in and by the end of 5th wk thymus approximates to the control in all parameters.

[The reactions of different sections of human embryonic neuroepithelium to damage to the ventricular surface during explantation]. / Reaktsii razlichnykh uchastkov neiroépiteliia émbrionov cheloveka na povrezhdenie ventrikuliarnoi poverkhnosti pri éksplantatsii.

Fragments of different regions of brain, spinal cord and retina obtained from 6 up to 7 wk human embryos were placed into media 199. On 24th hr of cultivation multiple invaginations developed in the explant ventricular surface as a response to its damage while preparing to explantation. Maturity extent of neural and glial elements was not essential to invagination intensity. Fragments of tectum and retina that are characterised by permanent shape of ventricular surface displayed minimal activity. These data suggest that the reaction considered reflects a property of neuroepithelial cells that constitutes an important factor in normal brain morphogenesis.

[Mitotic activity and rosette formation in the neuroepithelium of the embryonic human neocortex in vitro]. / Mitoticheskaia aktivnost' i obrazovanie rozetok v neiroépitelii émbrional'nogo neokorteksa cheloveka in vitro.

Fragments of anterior cerebral vesicle wall were exposed in 6-8 weeks human embryos and cultured for up to 48 hrs in media 199. Two types of neuroepithelial cells dynamics were demonstrated: the first one is associated with invaginative movements of the layer (apical contractions and elongation of neuroepithelial cell processes are seen, the other one-with cell mitotic division (apical processes become shorter and wider and nuclei reach germinal zone). Prevalent cell dynamics type is determined by media composition. Type I predominates in serum-free media, while type II-in media containing embryonal serum. The lack of correlation between the extent of neuroepithelial layer bending and number of mitotically dividing cells in it indicates invagination process independence from cell divisions. Thus, neuroepithelial layer invagination is not stimulated by mitotic activity and does not stimulate it.

[Rosette formation in explants of human embryonic neocortex (an electron-microscopic study)]. / Obrazovanie rozetok v éksplantatakh neokorteksa émbrionov cheloveka (élektronno-mikroskopicheskoe issledovanie).

Multiple invaginations and closed cavities (rosettes) were developed in 199 fragments of wall of human anterior cerebral vesicle. Contraction of neuroepithelial cells apexes after the principle of the gathered tobacco pouch was involved into the process. This confirms the previous suggestion of the authors on the similarity between the mechanisms of rosettes forming and neurulation. The participation of radial glia cells and neuroblasts in the reorganization of the neocortex germ was also studied.

[Vascularization of the human embryonic neocortex in the rat anterior chamber under cyclosporine A immunosuppression]. / Vaskuliarizatsiia neokorteksa émbrionov cheloveka v perednei kamere glaza krysy v usloviiakh immunosupressii tsiklosporinom A.

Fragments of 9 weeks hyman embryo neocortex were grafted into the rat eye anterior chamber. To prevent rejection cyclosporin A was introduced to the animals. Vascular network forming in transplants was studied for 5 weeks 3 days endothelial buds from the iris vessels appeared in transplants. After 10 days capillaries with erythrocytes appeared in the graft on the border with iris. 3 weeks later vascular network achieved its maximal development, occupying almost the entire graft thickness. The vessels developed diverged from the norm: they had variceal widenings, and focal distribution with significant non-vascular gaps.

[The effect of a serotonin deficiency on mammalian embryonic development]. / Vliianie defitsita serotonina na émbrional'noe razvitie mlekopitaiushchikh.

Administration of p-chlorophenylalanine to mouse females leading to a decreased level of endogenous serotonin during the early periods of pregnancy leads either to the absence of cytokinesis at the stage of zygote or to a sharp reduction of the cleavage rate in embryos up to its complete arrest. Formation of the blastocyst is impaired, although cavitation may take place at the same time as in the control. In the latter case, the blastocysts consist of a small number of large blastomeres, and the separation into trophoblast and inner cell mass is characteristically indistinct. Decreased level of endogenous serotonin at early postimplantation stages, i.e., during active organogenesis, leads to abnormalities in the development of brain, eyes, jaws, abnormalities of the brain vessels and vascular system of other body regions, which appear as numerous hematomas and hemostasis in vessels.

[The toxic effect of serotonin in direct and mediated actions on rat embryos]. / Toksicheskii éffekt serotonin pri priamom i oposredovannom deistvii na émbriony krysy.

Embryotoxic effect of serotonin in direct (intra-amniotic administration) and indirect (subcutaneous administration) treatment was studied. In both cases serotonin causes embryo death and different abnormalities in development in small number of embryos. Mechanism of serotonin embryotoxic effect is under discussion.

[The role of the maternal genotype in the realization of the embryotoxic activity of teratogens]. / Rol' genotipa materi v realizatsii émbriotoksicheskoi aktivnosti nekotorykh teratogenov.

Against the background of the induced iron deficit ethanol (6.4 g/kg) causes aggravation of the embryolethal effect and anomalies in 15% of embryos in 14-day pregnant rats. Changes in the genome of rat males and females after the injection of the plasmid with a foreign gene at the stage of two pronuclei and the subsequent crossing with intact animals account for the increase in sensitivity of embryos to subteratogenic doses of sodium salicilate. The maternal organism disturbances have a more pronounced effect than the paternal ones.

[The effect of sodium diethyldithiocarbamate on the development of organ anlagen in the mouse]. / Vliianie diétilditiokarbamata natriia na razvitie zachatkov organov myshi.

The effect of noradrenaline-depressing natrium diethyldithiocarbamate (DDK) on embryonic tissue was studied in histological preparations. Degenerative changes in cells were found in tissues, exposed to the effect on 10th day of the development. Masses of detrite appear to remove into the cavities of the organs and into the amniotic cavity of the saccus vitellinus which is the characteristic peculiarity of the degenerative changes. After effect on 9-day-year-old embryos degenerative changes were expressed in a different extent-from light in some embryos up to the massive ones in the others. Degenerative changes in giant trophoblast cells, nervous tube, eye rudiment etc were observed in the survived embryos, Prevailing location of the processes was not demonstrated. DDK manifests strong cytotoxic effect. This phenomenon is probably connected with the copper-containing enzymes depression, including those participating in noradrenaline synthesis.