Effect of Silicon Dioxide Nanoparticles on Syrian Hamsters Infected by Opisthorchis felineus: 1H MRS Study of the Brain

In recent years, silicon dioxide nanoparticles have been widely used in medicine and the pharmaceutical industry, however, their effect on the brain has hardly been studied. We assessed the effects of long-term consumption of 5-nm amorphous silicon dioxide nanoparticles (SiO₂-NPs) by Syrian hamsters infected with the trematodes Opisthorchis felineus on the hippocampus and frontal cortex. Spectroscopic determination of brain neurometabolites, performed using a horizontal Magnetic Resonance Imaging system at 11.7 Tesla magnetic field, has shown that the ratio of the excitatory neurotransmitters (glutamate + glutamine + aspartate) to the inhibitory ones (GABA + glycine) was higher in the animals infected with O. felineus. However, pre-consumption of the SiO₂-NPs solution prevented this imbalance. In addition, the protective effect of SiO₂-NPs on the level of myo-inositol and glycine was found. It is concluded that the use of SiO₂-NPs can neutralize the negative effects of infectious factors on the brain.

Treatment of Intervertebral Disc Degeneration in Wistar Rats with Mesenchymal Stem Cells

We studied the effect of erythropoietin on functional properties of mesenchymal stem cells under conditions of oxidative stress and their therapeutic potential in the treatment of intervertebral disc degeneration in Wistar rats. It was shown that erythropoietin stimulates proliferation under conditions of oxidative stress. Injection of bone marrow mesenchymal stem cells into the damaged intervertebral disc was followed by an increase in the height of the intervertebral disc and activation of repair processes in the nucleus pulposus. The combination of mesenchymal stem cells with erythropoietin provides the best effect of cell therapy in case of intervertebral disc damage.

[Repetitive resection and intrasurgery radiation therapy of brain malignant gliomas: history of question and modern state of problem]

Numerous studies have shown that the degree of primary resection of malignant gliomas of the brain (MG) directly correlates with rates of relapse-free and overall patient survival. Currently, there is no unequivocal opinion regarding the indications and effectiveness of repeated resection in relapse of MG after combined treatment. Surgical intervention, taking into account the pathomorphological features of these tumors, is not healing and should be supplemented with certain methods of adjuvant treatment. The article reviews and analyzes publications devoted to repeated resection and various methods of intraoperative radiation therapy in the treatment of MG. Based on the analysis, the authors of the article came to the conclusion that it is advisable to start their own research on the use of intraoperative balloon brachytherapy in the treatment of recurrent MG based on modern technological solutions.

Efficiency of endovascular embolization and predictors of postoperative complications in patients with different types of brain arteriovenous malformations

<p><strong>Aim.</strong> (1) To evaluate the efficiency of endovascular embolization of brain arteriovenous malformations (AVMs) with seizure or hemorrhage in relation to radicalness and postoperative complication development and (2) to determine the predictors of postoperative complications after endovascular embolization of AVMs.</p><p><strong>Methods.</strong> In this retrospective study, we examined the treatment of 192 patients with brain AVMs with seizure (seizure group; n = 85) or hemorrhage (hemorrhage group; n = 107). All the patients underwent total endovascular embolization of the malformations, and the follow-up period was 12 months. The two different patient groups were identified, and the predictors of the development of adverse events (hemorrhagic and ischemic complications) in the early postoperative period (hospital stay) were determined.</p><p><strong>Results.</strong> Twelve months after control cerebral angiography was performed, recanalization was observed in 7 (8.2%) and 14 (13.1%) patients in the seizure and hemorrhage groups, respectively (p = 0.432). The frequency of complications was 20% and 29.9% in the seizure and hemorrhage groups, respectively (p = 0.162). The mortality rate during hospitalization was 0% and 9.3% in the seizure and hemorrhage groups, respectively (p = 0.026). Multivariate regression analysis revealed that a history of hemorrhage, the location of AVMs in functionally significant zones, and a large maximum size of AVMs are predictors of the development of postoperative complications.</p><p><strong>Conclusion.</strong> Endovascular embolization is an effective, minimally invasive approach for the treatment of different types of brain AVMs. Considering the natural risks of brain AVMs according to the literature, endovascular embolization is associated with a low frequency of early postoperative complications.</p><p>Received 14 February 2019. Revised 24 May 2019. Accepted 28 May 2019.</p><p><strong>Funding:</strong> The study did not have sponsorship.</p><p><strong>Conflict of interest:</strong> Authors declare no conflict of interest.</p>

Spinal cord stimulation in treatment of patients with critical lower limb ischemia

<p>Critical limb ischemia (CLI) is a state of substantial reduction of blood flow in the extremities, mostly due to severe obstruction of the arteries. In lower limbs, it produces severe pain after even a short distance walk (intermittent claudication) and/or skin ulcers or sores. Surgical revascularization is a “golden standard” in CLI therapy, but it is contraindicated or not accessible for a large proportion of patients, while the medical prognosis is poor for conservative therapy. This situation stimulated the development of alternative approaches, including spinal cord stimulation (SCS) and various methods of “indirect” revascularization. In this paper, the authors give a short description of the latest approaches and a detailed review of the SCS method, while paying special attention to the studies that demonstrate not only a palliative effect of SCS (pain reduction), but also clinically significant changes in the indicators of lower limb muscles blood supply. CLI is characterized with a "vicious circle": pain causes reduced mobility and changes in the preferred limb position, which in turn lead to edema triggering an increase of ischemia and further elevation of pain. The clinical effects of SCS in CLI patients are related both with pain relief leading to a break of this vicious circle, and with the direct vasodilatory effects of the stimulation itself. There are several possible biological mechanisms of these actions, but most probably the therapeutic actions of SCS arise from their combination. Examination of different opinions about the appropriateness of spinal cord stimulation in patients with CLI, including those related to the economic efficiency of the method, leads to the conclusion that the evidence on these issues is currently insufficient. The reviewed data demonstrate the need for further development of the CLI treatment methods and high urgency of this problem.</p><p>Received 6 April 2017. Accepted 23 April 2017.</p><p><strong>Funding:</strong> The study did not have sponsorship.<br /><strong>Conflict of interest:</strong> The authors declare no conflict of interest.</p>

[Clinical guidelines for the use of intraoperative fluorescence diagnosis in brain tumor surgery]

In this paper, we present a review of current literature on the application of intraoperative fluorescence diagnosis and fluorescence spectroscopy using 5-aminolevulinic acid in surgery for various types of brain tumors, both alone and in combination with other neuroimaging methods. Authors' extensive experience with these methods allowed them to develop a set of clinical guidelines for the use of intraoperative fluorescence diagnosis and fluorescence spectroscopy in surgery of brain tumors.

[Transarterial and transvenous embolization of deep binodal arteriovenous malformation of the brain]

INTRODUCTION

The multimodal approach to treatment of arteriovenous malformations yields good results. However, small and deep malformations still pose a big problem for surgeons. Transvenous embolization was designed as an alternative for the cases when endovascular treatment is required and conventional transarterial embolization is not available.

CASE STUDY

A 41-year-old patient with binodal malformation in the subcortical nuclei of the left hemisphere of the brain, which had previously become a source of massive parenchymal ventricular hemorrhage, was operated on using the transarterial and, for the first time in our clinic, transvenous approaches. Transarterial embolization of the thalamic node of malformation was performed as the first step. After 6 months, transvenous embolization of the hypothalamic node of malformations was performed as the second step. Successful operation was ensured by using a stable coaxial guiding catheter system with the maximum distal approach and intranidal positioning of a microcatheter with detachable distal portion upon temporary occlusion of afferent vessels of the malformations using a balloon catheter. The operation resulted in total thrombosis of the malformation. No perioperative complications were observed. Control examination in 6 months did not reveal recanalization of the malformation.

CONCLUSION

The transvenous approach can be successfully used in endovascular treatment of small and deep arteriovenous malformations with a single drainage vein, which are inaccessible to direct surgery. It can also be used when radiosurgery is associated with a high risk in cases where transarterial embolization is infeasible.

Results of surgical treatment of patients with glioblastomas using a combined 5-ala fluorescent-guided resection

Glioblastoma (GBM) is the most common primary malignant brain tumor in adults. It was previously shown that 5-ala fluorescence-guided resection (FGR) of malignant gliomas, as compared to white-light microscopy resection, demonstrates a significantly higher frequency of complete removal of the contrast-enhancing tumor and significantly prolongs overall survival. A combination of 5-ala microscopy and endoscopy may provide some benefits for GBM surgery. The purpose of this study was to evaluate the immediate results of combined 5-ala FGR in patients with GBMs. All in all, 80 patients with GBMs were operated at two independent neurosurgical centers. Patients of the first group (n = 40) were operated by using the combination of 5-ala microscopy and endoscopy. The second (control) group patients (n = 40) underwent conventional white light microsurgery. MRI with contrast agent was done preoperatively and within 72 hours after surgery accompanied by volumetric analysis of the tumor. The patients' functional class was determined a day before surgery and 10 days after it. A comparative analysis of GBM resection by using MRI neuronavigation and combined fluorescence-guided navigation shows that the latter considerably increases the total percentage of GBM resection (27.5% and 65% respectively) and improves the functional class in the immediate postoperative period.

New software for objective evaluation of brain glioblastoma resection degree

The visual evaluation of the degree of GBM resection based upon postoperative enhanced MRI is still difficult. It is explained by intricate complex of tumor residual fragments, blood cells, hemostatic tissues and perifocal edema that located in the postoperative area. We introduce the new software-based method for postoperative MRI data's objective estimation. Five independent specialists had examined 16 patients' MRI data (including 12 GBM and 4 patients with noninfiltrative intracerebral tumors) and tested the method's specificity and sensitivity against the enhanced residual tumor (ERT). Our software determines the 100% sensitivity and specificity against hemostatic agent Surgicel, the high recurrence rate of results while estimating the volume of ERT (0,14 ± 0,02 cm³) and low considerable time (5,21 ± 0,14 min). The software was can be used both daily practice and research of malignant glioma management.

Trepanations in the population of the Altai Mountains in the Vth - IIIrd centuries B.C

The history of trepanations beginning with the Mesolithic (1 0-12 thousand years ago) is known by means of findings in various parts of the world. The article describes three cases of intravital trepanation of skulls from the Pazyryk Culture graves in the Altai Mountains that had existed from the end of the Vl'h to the beginning of the ll"d century B.C. In two cases, trepanations were performed so skillfully that the operated patients had survived for a long time after the surgery, which was confirmed not only by microscopy but also by MSCT of the skulls. The article establishes causes of surgeries performed, reconstructs the technique of surgical manipulations, and evaluates them in terms of modern medicine. A comparative analysis of ancient trepanations performed by healers of different archeological cultures is provided. It is concluded that prehistoric cranial surgeries in the Altai Mountains had been performed for curative purposes.

[Oncolytic viruses in the therapy of gliomas]

Despite the advances of modern medicine, malignant glioblastoma cure remains an elusive goal. Both the invasive nature and location in vital areas of the brain make this type of tumors difficult for surgical treatment, while the current adjuvant therapy is not as successful as expected. Frequent recurrence and invasiveness of malignant gliomas is due to resistance of glioma stem cells to conventional radiation and chemotherapy. Technological advances in constructing recombinant viruses have allowed creating strains with high oncolytic activity toward glial tumors. Many of these strains have passed Phase I of clinical trials and demonstrated high safety. Despite the obvious potential of the approach, efficiency of the existing strains is still far from being sufficient for effectively curing the disease and require further improvement. The review summarizes results obtained with the most successful variants of oncolytic viruses that come down to the clinical trials and discusses the prospects for new approaches in virotherapy of malignant gliomas.

[Results of radical removal of malignant cerebral gliomas, by using computer-assisted navigation, followed by adjuvant therapy]

A retrospective cohort analysis of the results of treatment of patients with malignant gliomas was made in 2 groups, each comprising 43 patients. In Group 1, the tumors were radically removed under neuronavigation guidance ("Voyager SX"). In Group 2 where the patients were operated on by the same team of surgeons who did not employ computer-assisted navigation technologies. The results of different adjuvant therapy regimens were analyzed in patients after radical tumor removal under navigation guidance (Group 1). In its first subgroup, 24 patients with anaplastic astrocytes were postoperatively irradiated (60 Gy), followed by treatment with temodal (200 mg/m2 (mean 6 courses). In the second subgroup, 12 patients received chemoradiotherapy (temodal, 75 mg/m2 daily + irradiation), followed by courses (n=6) of temodal, 200 mg/m2). In the third subgroup, 7 patients were treated with fotemustin (200 mg/m2 (induction) + 5 cycles). The computer-assisted technologies substantially improve a postoperative outcome in patients with malignant glionas. Current chemoradiotherapy is relatively safe and prolongs a relapse-free interval with a high quality of life. Further studies call for the efficiency of different adjuvant therapy regimens after radical surgery.

[Electroencephalography monitoring at total and managed hyperthermia to 44 degrees C]

In 34 patients the abstinence syndrome was treated by hypothermia (HT) with the EEG monitoring. HT was carried out under the general propofol-fentanil anesthesia. HT was achieved in the "Hirana" bath. The temperature was increased gradually by 1 degree C per 5 minutes up to 44 degrees C. EEG was recorded before anesthesia, as well as during and after the procedure. On the initial EEG alpha- and beta-rhythms were predominant. Under the anesthesia both alpha-rhythm frequency and amplitude were enhanced, spikes and wave discharges appeared. Under HT (t = 40-42 degrees C) low voltage and wave slowing were recorded. In the range t degree--42.5-43.4 degrees C EEG registered the appearance of clinically significant "biological break point", which was followed by neuropeptide destruction. At t degree--43-44 degrees C acute suppression and, then, electrocerebral silence were observed in a majority of patients. At the end of the procedure (t = 39 degrees C) EEG returned to the initial recording.

[Magnetic resonance tomography in the diagnosis of tumor processes in the area of the cerebellopontile angle]

The paper provides the results of magnetic resonance tomographic examination of patients with acoustic neurinoma, and shows that the method can be used in the defining the site of a focus, its size, and relations of the tumor with adjacent tissues. The paper also outlines the image structure of the tumor in relation to scanning techniques and gives magnetic resonance criteria for differential diagnosis of tumor processes in the region of the cerebellopontine angle. It is concluded that magnetic resonance tomography is of high informative value in the diagnosis of extra-axial tumors of the posterior cranial fossa.

[The reactions of the capillary bed of the skeletal muscles to normobaric hyperoxia and a perfluoro-organic blood substitute]

The capillary density of the m. cremaster decreased while the RBC velocity and tube hematocrit remained constant during oxygen respiration in rats. The blood substitute induced opposite changes. The data suggest that the RBC velocity decrease depended on the blood rheological properties due to addition of submicron particles of the blood substitute and not to its oxygen capacity.

[The corrective effect of perfluorocarbon emulsions on the cerebral hemodynamics in craniocerebral trauma]

The article discusses the results of study of the effect of perfluorocarbons on the cerebral blood flow and metabolism of an intact brain and in severe graded craniocerebral injury in experiments on 25 dogs. The results make it possible to prognosticate the efficacy of using preparations based on emulsions of organoperfluorine compounds in neuroreanimatology to correct disorders of cerebral blood flow and metabolism in the foci of brain contusion.

Correlation of MRI and CT data with outcome of cerebral revascularization after stroke

Sixteen patients with the occlusion of the internal carotid artery (ICA) underwent extra-intracranial bypass surgery. All patients had stroke in evolution or completed stroke with mild or moderate (n = 9) or severe (n = 7) neurological deficits. In each case, the clinical course, magnetic resonance imaging (MRI), computed tomography (CT) and angiographic (AG) findings were evaluated. Patients were followed up from 9 months to 2.5 years postoperatively. MRI was much more sensitive than CT for appreciating the ischaemic tissue. The infarct volume determined by MRI had greater extent than previously detected by CT. If the difference of the infarct volume, detected by MRI and CT was more than 30% the patients appeared to have benefited from bypass surgery as demonstrated clinically as well as with postoperative MRI and AG studies. Patients with lesser difference showed insignificant or no postoperative improvement.

[The dynamic NMR tomographic picture after cerebral revascularization in patients with ischemic stroke]

The authors discuss the results of a MR tomographic examination in 12 patients with ischemic apoplexy who underwent operation for the formation of an extra-intracranial microanastomosis. It is shown that MR tomography is a valuable diagnostic method which allows visualization of the ischemic foci. It is proved that in combination with CT it yields valuable information for determining the indications for revascularization of foci of ischemia in the brain.