[Stereotactic radiosurgery in treatment of trigeminal neuralgia]. / Stereotaksicheskaia radiokhirurgiia v lechenii trigeminal'noi nevralgii.

It was not until relatively recently that the method of stereotactic radiosurgery has started to be used for treating trigeminal neuralgia. Being minimally invasive, this method can be considered an attractive alternative to invasive surgical methods. OBJECTIVE: The objective of this study was to analyze the results of treatment in patients with trigeminal neuralgia using the Leksell Gamma Knife system. MATERIAL AND METHODS: The results of stereotactic radiosurgery were analyzed in 52 patients (31 females and 21 males aged 31 to 79 years) who had undergone treatment at the Radiosurgical Center of MIBS (St. Petersburg) in 2009-2016. Forty-four patients were diagnosed with typical trigeminal neuralgia; four patients, with atypical neuralgia; and four patients, with symptomatic neuralgia (accompanying multiple sclerosis). Pain severity was assessed using the Visual Analogue Scale (VAS) and the Barrow Neurological Institute Scale (BNIPS) before and after the surgery, as well as during the follow-up period (mean duration, 3 years). RESULTS: Pain was reduced in 38 (86.4%) patients with type 1 neuralgia. The effect usually was not observed immediately after the surgery but was delayed from several weeks to 12 months (median, 2 months; interquartile range) [1, 4]. The surgery was ineffective in 6 (14%) patients. Eight (18%) patients had a relapse on average after 2 years and 5 months. By the end of the follow-up period, score I according to the BNIPS was achieved in 22 (50%) patients; score II or III was achieved in 7 (16%) patients. Primary reduction of pain was achieved in two patients with type 2 neuralgia; one of them had a relapse after 19 months. Among patients with symptomatic neuralgia, the primary effect was achieved in three patients, but two of them later had a relapse. CONCLUSION: Stereotactic radiosurgery can be used to alleviate pain in most patients with type 1 trigeminal neuralgia, but its results are inferior to those of invasive interventions. According to our findings, 18% of patients had a relapse. For patients with multiple sclerosis accompanied by type 2 and symptomatic trigeminal neuralgia, this method is not sufficiently effective. When both microvascular decompression and stereotactic radiosurgery can be used to treat for type 1 and 2 trigeminal neuralgia, patient's choice is crucial. It is important to inform the patient both about the potential complications of the interventions and about the delayed effect of the surgery and relapse frequency.

Evaluation of the separation and purification of 227Th from its decay progeny by anion exchange and extraction chromatography.

Thorium-227 is currently undergoing evaluation as a potential radionuclide for targeted cancer therapy, and as such a high chemical purity of the material is required. To establish a reliable procedure for radiochemical isolation of 227Th from the parent 227Ac and decay progeny, which includes the radiotherapeutic 223Ra, the performance of three different separation schemes based on ion-exchange and extraction chromatography have been evaluated. The results suggest that both ion exchange and extraction chromatographic techniques can be successfully used for the separation of 227Th from its decay progeny, however extraction chromatographic resins demonstrate favourable performance in terms of Th recovery and purification from radionuclide impurities.

[Analysis of results of Gamma Knife radiosurgery for patients with melanoma brain metastases].

The outcomes of Gamma Knife radiosurgery for 95 patients with melanoma brain metastases were studied. The majority of the patients (82%) presented multiple metastatic brain lesions. Local control was achieved in 94% of cases. The Kaplan-Maier analyses of life expectancy revealed that median survival after radiosurgical treatment was 6.9 months. The median survival by RTOG RPA class was 18,3 months for class I; 6.9 months for class II and 3.9 months for class III. These results demonstrate that Gamma Knife radiosurgery provides a high level of local control for melanoma brain metastases and may increase the life expectancy.

Cyclotron production and radiochemical purification of (88,89)Zr via α-particle induced reactions on natural strontium.

The radionuclides (88)Zr and (89)Zr have been produced by cyclotron irradiation of (nat)SrO with 35 MeV α-particles at a beam current of 15 µA. The thick source production yield of (89)Zr is ~3.1 MBq µA(-1) h(-1). A two-step radiochemical purification utilising anion-exchange chromatography in hydrochloric and hydrofluoric acids has been developed to separate (88,89)Zr from the target material, natural strontium, the target substrate, aluminium, and long-lived (88)Y.

[Results of gamma-knife radiosurgery treatment for intracranial metastases of renal-cell cancer and prognostic factors influencing on the survival (joint study of three Eastern European Centers)].

Gamma-Knife radiosurgery treatment for intracranial metastases of renal-cell cancer results are presented. Treatments were made in 3 Eastern European Centers: in Prague, Moscow and St. Petersburg from 2000 to 2011. 312 patients were treated. Median survival was 8 months (1-91 months). Follow up data were collected for 210 patients. Neurologic state worsening had place at 12% patients, but only 4% of deterioration cases are connected to GKRS. Causes of the rest cases are related to new metastases. Neurologic improvement was found at 29% of patients. Post-RS MRI data were available for 188 patients. Volume enlargement was observed at 10% of cases, but only 5% caused by continued growth. New metastases appeared at 53% of patients. Actuarial analysis didn't detect statistically significant differences in survival for such parameters as patient age, volume and number of metastases. Favorable prognostic factors (p < 0.05) were found to be Karnofsky state equal or more than 70, controlled primary tumor and absence of extracranial metastases, as well as marginal dose for largest metastasis more than 20 Gy. Now RS is one of the basic method of the discussed pathology treatment, that demonstrates high efficacy in relation to the tumor growth and the patient Quality of Life. It is noteworthy that the length of survival is determined by the depth of the complex treatment of primary disease and success of such treatment.

Study of the 111In-DTPA complex by the electromigration method.

The electrophoretic behavior of the 111In-DTPA radiopharmaceutical has been investigated. The stability constant, diffusion coefficient and effective charge of the complex as well as the temperature dependence of the electrophoretic mobility were determined. No-carrier-added 111In with high specific activity was used in the electrophoretic experiments in ultramicroconcentrations (10(-9)M).

Tubular structures of Mycoplasma gallisepticum and their possible participation in cell motility.

In five strains of Mycoplasma gallisepticum, a protein with a molecular mass of about 40 kDa was detected by immunoblotting with anti-pig brain tubulin polyclonal and monoclonal antibodies. In eight other mycoplasma species similarly tested no reaction was observed. Thin serial sections of M. gallisepticum and Acholeplasma laidlawii cells examined by transmission electron microscopy revealed a submembrane system of tubules in M. gallisepticum but not in A. laidlawii. The intracellular spatial distribution of the tubular structures was reconstructed. Thin sections of M. gallisepticum treated with anti-tubulin antibodies and colloidal gold particles (immunogold labelling) revealed distinct labelling of the tubular system. Analysis of the tubular structures by high resolution electron microscopy and optical diffraction showed their helical organization to be: diameter 40 nm, helix pitch approximately 20 nm and electron-transparent core 10 nm in diameter. A possible involvement of the tubular system in mycoplasma motility is suggested.

[Tubular structures in Mycoplasma gallisepticum and the localization of a tubulin-like protein]. / Tubuliarnye struktury Mycoplasma gallisepticum i lokalizatsiia tubulinopodobnogo belka.

In all the strains of M. gallisepticum investigated, a protein with apparent molecular weight 40 kDa was revealed by immunoblotting with polyclonal anti-calf brain tubulin antibodies and monoclonal anti-chicken alpha-tubulin antibodies. In other 8 investigated Mycoplasma species no positive reactions with the same antibodies were found. The M. Gallisepticum cells were examined under electron microscope on fine serial sections and on some sections going at different angles to the long cell axis. Undermembrane system of tubules was revealed and the intracellular pattern of the tubular structures were reconstructed. The immunoelectron microscopic data suggest that tubulin-like protein may be included into the structures.

[Neurophysiologic analysis of the critical period of delay of a reinforcing stimulus in the dog]. / Neirofiziologicheskii analiz kriticheskogo perioda otstavleniia podkrepliaiushchego razdrazhitelia u sobak.

At interval of less than 100 ms between indifferent sound and unconditioned electrocutaneous stimulation, classical defensive conditioned reflex is not elaborated in dogs, in full correspondence with literature data. But intracortical temporary connection is established; this fact is shown by electrographic phenomena, the most specific and demonstrative among them is "conditioned evoked potential". The absence of behavioural (peripheral) and presence of electrographic (central) manifestations allow to assume that for the formation of the conditioned reflex of full value the involvement is necessary of additional activational (motivational) mechanisms, connected with reticular and (or) limbic subcortical structures which do not react to the conditioned stimulus at time deficit in conditions of microdelay.