An analytical approach to optimization of isotope production by bremsstrahlung radiation.

Based on analytical description of isotope production by bremsstrahlung (X-ray) radiation, an algorithm is proposed for calculating the optimal dimensions of a cylindrical target of given mass positioned at a given distance from a bremsstrahlung converter to ensure the maximum yield of the isotope product. The expressions are derived for the total activity and its distribution along the target axis. A technique of γ-spectrometric measuring the activity of a thick production target is proposed. The novel approach is validated by the 100Mo(γ,n)99Mo reaction induced in a natural molybdenum target by mass in the range 10-100g with the X-ray photons at an end-point energy of 40 MeV. The analytical predictions are in good agreement with the results of Monte-Carlo simulations and experiment.

A method of determining the bremsstrahlung flux-weighted average photonuclear cross section.

Based on a developed analytical model, a method is proposed for measuring the photonuclear cross section averaged over bremsstrahlung flux without application of additional target-monitor of photon flux. The method involves the use of a thin isotopic target, that completely overlaps the photon beam (a photonuclear converter), as well as an algorithm for processing the data on the yield of a reaction under study in such a target. The novel technique was validated on the reactions 100Mo(γ,n)99Mo and 58Ni(γ,n)57Ni in the range of photon end-point energy of 40.7-93.9 MeV. The photon flux-weighted average cross sections of the reactions measured experimentally are in good agreement with Monte Carlo simulations and TALYS predictions on their excitation functions.

Development and validation of an analytical model of isotope production by bremsstrahlung radiation.

An analytical method is used to describe isotope production at an electron accelerator. The key characteristics that determine the total target activity and its distribution have been established. The expressions for the reaction yield depend explicitly on the irradiation regime and parameters of the giant dipole resonance. The model predictions for the bremsstrahlung spectrum and yield of the reference reactions are in good agreement with the results of simulation and experiment.

Safety and efficacy of superior rectal artery embolization with particles and metallic coils for the treatment of hemorrhoids (Emborrhoid technique).

PURPOSE: The purpose of this study was to comprehensively evaluate the short-term outcomes after percutaneous embolization of the superior rectal artery (SRA) with metallic coils and particles for the management of hemorrhoids. MATERIALS AND METHODS: Forty patients (15 men, 25 women) with a mean age of 35±5 years (SD) (range: 25-65 years) were prospectively enrolled. All patients had symptomatic hemorrhoids. The distribution of internal hemorrhoids was as follows: grade I (n=6, 16%); grade II (n=28, 69%) and grade III (n=6; 15%). All patients had percutaneous embolization of the SRA with metallic coils and synthetic polyvinyl alcohol particles. Follow-up evaluation included clinical examination, rectoscopy, histopathological analysis of rectal mucosa, duplex Doppler blood flow quantification, electromyography, sphincterometry of the anal sphincter and analysis of patient satisfaction. RESULTS: No immediate complications were observed and no patients had anal pain syndrome after embolization. Hemorrhoids showed a 43% size reduction after embolization (P<0.05). Taking into account the symptom resolutions such as irritation, discomfort, bloody discharge and pain, satisfaction was observed in 5/6 (83%) patients with grade III hemorrhoids and 32/34 patients (94%) with grades I-II hemorrhoids. One month after embolization, anal sphincter contractility normalized and no changes in anal electromyography were observed. Blood flow in the hemorrhoidal plexus dropped from 109±1.2ml/min/100g (SD) before treatment to 60.2±4.4ml/min/100g (SD) (P<0.05) the day after embolization and remained unchanged one month after embolization. CONCLUSION: Our study demonstrates that embolization of SRA with particle and coils does not lead to ischemia in patients with symptomatic hemorrhoids. Short-term results with regard to symptom management for hemorrhoidal disease are very encouraging and should stimulate further prospective and multicenter studies.

[Effects of Light Near-Infrared Radiation on Rats Assessed by Succinate Dehydrogenase Activity in Lymphocytes on Blood Smears].

Biological effects of light near infrared radiation (850 nm), with modulation acoustic frequency of 101 Hz, was studied. The study was conducted on rats, the effect was recorded by succinate dehydrogenase activity in lymphocytes on the blood smear after administration of the activating dose of adrenaline, which simulates the state of the organism in the early stages of the pathogenic effects (stress). A pronounced regulating effect of infrared radiation on the activity of succinate dehydrogenase in animals activated by adrenaline was shown. Infrared radiation has a normalizing effect reducing the degree of inhibition or activation of the enzyme induced by adrenaline and had no effect on the control animals. Thus, by modulating the activity of succinate dehydrogenase infrared radiation regulates energy production in the mitochondria supported by the most powerful oxidation substrate--succinic acid, which is especially pronounced under stress.

[MIRABEGRON. WHETHER WILL BE A REVOLUTION IN THE PHARMACOTHERAPY OF OVERACTIVE BLADDER?].

This article provides an overview of the current state of the problem of effective pharmacotherapy for overactive bladder (OAB). The review presents standard pharmacotherapy and a new stage in the treatment of OAB--innovative drug Mirabegron. International and domestic studies confirmed high and predominant in many respects efficacy of mirabegron and a good safety profile. Conducted at the Research Institute of Urology own research demonstrated no influence on the quality of the bladder emptying, which proves the urodynamics safety. Taking into account the efficacy of mirabegron for all OAB symptoms, proven in a Randomized Clinical Tials (RCT), mirabegron has big potential and is able to make a revolution in the pharmacotherapy of OAB.

Burst of succinate dehydrogenase and α-ketoglutarate dehydrogenase activity in concert with the expression of genes coding for respiratory chain proteins underlies short-term beneficial physiological stress in mitochondria.

Conditions for the realization in rats of moderate physiological stress (PHS) (30-120 min) were selected, which preferentially increase adaptive restorative processes without adverse responses typical of harmful stress (HST). The succinate dehydrogenase (SDH) and α-ketoglutarate dehydrogenase (KDH) activity and the formation of reactive oxygen species (ROS) in mitochondria were measured in lymphocytes by the cytobiochemical method, which detects the regulation of mitochondria in the organism with high sensitivity. These mitochondrial markers undergo an initial 10-20-fold burst of activity followed by a decrease to a level exceeding the quiescent state 2-3-fold by 120 min of PHS. By 30-60 min, the rise in SDH activity was greater than in KDH activity, while the activity of KDH prevailed over that of SDH by 120 min. The attenuation of SDH hyperactivity during PHS occurs by a mechanism other than oxaloacetate inhibition developed under HST. The dynamics of SDH and KDH activity corresponds to the known physiological replacement of adrenergic regulation by cholinergic during PHS, which is confirmed here by mitochondrial markers because their activity reflects these two types of nerve regulation, respectively. The domination of cholinergic regulation provides the overrestoration of expenditures for activity. In essence, this phenomenon corresponds to the training of the organism. It was first revealed in mitochondria after a single short-time stress episode. The burst of ROS formation was congruous with changes in SDH and KDH activity, as well as in ucp2 and cox3 expression, while the activity of SDH was inversely dependent on the expression of the gene of its catalytic subunit in the spleen. As the SDH activity enhanced, the expression of the succinate receptor decreased with subsequent dramatic rise when the activity was becoming lower. This article is part of a Directed Issue entitled: Bioenergetic dysfunction, adaption and therapy.

Rhythms of cell division of different periodicity in small intestinal cryptic epithelium and their contribution to circadian rhythm formation.

We used an improved method of chronobiological information processing enabling not only to detect oscillations with different frequencies, but also to determine the significance of each harmonic. This has made it possible to identify significant high-power harmonics present in the majority of cell positions in the crypt. These harmonics make the major contribution to the formation of diurnal rhythm of cell division in the crypt and hence determine spatial and temporal organization of the proliferative system in the crypt.

Study of biological rhythms of small intestinal cryptic epithelial mitosis of different periodicity by fourier analysis.

Rhythms of cell division with different periods in the mouse small intestinal cryptic epithelium were studied using Fourier analysis. It was found that the proliferative system of the crypt is characterized by an intricate spatial and temporal organization. The amplitude of low-frequency rhythms increases, while the amplitude of high-frequency rhythms decreased in the direction from the crypt bottom to the neck.

[Results of bidirectional cavapulmonary shunt operation without cardiopulmonary bypass in children with complicated congenital heart defects during the first year of life].

The authors present results of bidirectional cavapulmonary shunt operation without cardiopulmonary bypass for the treatment of complicated congenital heart defects. Temporary blood shunting during surgical intervention enables cavapulmonary anastomosis to be created without making resort to artificial circulation (AC) and limitation on the time of superior vena cava occlusion. The proposed method is free from additional risks and excludes negative effects of AC. It allows for conversion to AC as appropriate at any time during surgery in the "bypass stand-by" regime.

Hyperactivation of succinate dehydrogenase in lymphocytes of newborn rats.

We measured the activity of mitochondrial succinate dehydrogenase (SDH) within cells, in media with near-physiological composition, in lymphocytes immobilized in a blood smear on glass. SDH activity was studied in newborn rats characterized by natural hyperadrenergic status and also in adult animals injected with epinephrine. In most newborns very high activities were recorded, which exceeded the activities in adults at rest 7-8-fold or 3-fold according to the conventional calculation, or more than 30- and 6-fold according to our more precise calculation. The findings support our concept about a selective interaction between adrenergic stimulation and oxidation of succinic acid. According to this concept, epinephrine and norepinephrine specifically activate oxidation of succinic acid, whereas blood micromolar concentrations of the latter stimulate the release of catecholamines (the receptor-mediated signaling effect). This interaction is half of a substrate-hormonal regulatory system responsible for connection of vegetative nervous system with oxidation in mitochondria of the innervated organs. The increase in succinate oxidation by catecholamines includes activation of the faster pathways of succinate generation than the complete Krebs cycle, in particular, the glyoxylate cycle that is shown in the newborn rats in the present study.

[An eight-year experience of cryotherapy of acrive retinal retinopathy in prematures: management of patients and results].

The paper represents an eight-year experience of active retinopathy of prematures (RP) by the method of transscleral cryopexy of the retinal zone in 91 patients (181 eyes) The time period and periodicity of ophthalmologic follow-up of prematures with RP risk are defined; indication and contraindications for cryotherapy are formulated; complications observed at the early postoperative period are pointed out. Cryotherapy was shown to be an effective method of treatment in RP: favorable treatment results were registered in 54.5% of cases. There are also results of a comparative analysis of the clinical refraction condition observed in RP patients in 4.8-5 years after cryotherapy. Myopia was by far more often diagnosed in the group of RP patients (38.2%). This parameter made 12% (p < 0.001) in the group of equal prematures.

[Spiral computed contrast tomography in diagnosis of juvenile angiofibroma of the base of the skull]. / Spiral'naia komp'iuternaia tomografiia s kontrastiroaniem v diagnostike iunosheskoi angiofibromy osnovaniia cherepa.

The authors present their experience in surgical and combined treatment of juvenile angiofibroma of the base of the skull (JABS). A total of 180 children were treated, 93.8% of them had advanced tumor and were operated through external approach by Moore. Computed and MR tomographies were made preoperatively and postoperatively in all the patients. Benefits and drawbacks of the above tomographies are analysed. A technique of spiral computed contrast tomography in JABS is described. This tomography has the following advantages: volume visualization of the studied area without artefacts induced by movements; sharper visualization of the vessels; possibility of retrospective reconstruction of the sections with varying interval after the end of the procedure; improved quality of multi-plane reconstructions; reduced radiation dose and time of exposure.

[Significance of tissue pH in the prognosis of postoperative complications in heart surgery patients]. / Znachenie tkanevogo pH dlia prognoza posleoperatsionnykh oslozhnenii u kardiokhirurgicheskikh bol'nykh.

Ischemia of the gastrointestinal mucosa is characterized by acidosis in the submucosal layer during the majority of interventions, which necessitates monitoring of tissue pH (pHi) of the abdominal organs during aortocoronary bypass surgery and the immediate postoperative period. The pHi was measured by gastrotonometry with a nasogastral tube (Trip catheter) and Tonocap-TC200 device (Datex Engstrom, Finland); pHi was measured in 17 patients in department of intensive care on days 1 or 2 after cardiosurgical interventions with at least 120-min artificial circulation and in 23 patients during the operation. Surgical treatment consisted in correction of acquired valvular diseases, myocardial revascularization (shunting operations), and combinations of these operations. The first stage of investigation revealed a relationship between decreased pHi level to the acid values and complicated course of the postoperative period. The second stage showed that postoperative complications occurred in 27.2% cases only in patients subjected to long artificial circulation bypass (more than 120 min). The frequency of complications were 2-fold more in the patients with tissue acidosis (pHi < 7.35) during surgery than in patients with normal and alkaline pHi values. The following complications occurred: acute pancreatitis, acute peptic ulcer, acute renal and polyorgan failure. Comparative analysis of pHi and other metabolic markers of arterial blood showed a correlation between these parameters, but pHi was more specific for the diagnosis of tissue ischemia. Hence, a low invasive highly specific method of gaseous gastrotonometry helps evaluate the blood supply to abdominal organs during and after cardiac surgery with artificial circulation and predict postoperative gastrointestinal and grave systemic complications (sepsis, acute renal failure, and polyorgan failure).

[Reconstructive and restorative surgeries of the large intestine]. / Rekonstruktivnye i vosstanovitel'nye operatsii na tolstoi kishke.

Reconstructive-restorative operations in 164 cases of colostomy are analysed. The colostomy was formed for injury to the large intestine in 45.7%, oncoproctological diseases in 35%, complications of diverticulum in 10%, and for other diseases (volvulus of the sigmoid colon, unspecific ulcerous colitis, etc.) in 9.3% of patients. The terms of the operations were chosen individually: from 2.5-4 months after injury to 10-14 months after an oncological operation. The extraperitoneal method was applied in 93 and the intraperitoneal method in 71 operations. Mortality was 2.9%.

[Change in the passive influx of Ca2+ into sarcoplasmic reticulum vesicles as a result of chemical modification of surface amino groups]. / Izmenenie passivnogo vkhoda Ca2+ v vezikuly sarkoplazmaticheskogo retikuluma v rezul'tate khimicheskoi modifikatsii poverkhnostnykh aminogrupp.

Treatment of sarcoplasmic reticulum (SR) vesicles with trinitrobenzene (TNBS) and 1-ethyl-3(3-dimethylaminopropyl)carbodiimide (EDC) stimulates the initial rate of passive influx of Ca2+ into SR vesicles, but does not affect either the binding or the maximal passive loading of SR vesicles with Ca2+. The changes in the kinetics of KCl-stimulated passive influx of Ca2+ depend on the reagent used. It is supposed that stimulation of passive influx of Ca2+ into SR vesicles and the changes in the reaction kinetics may be caused by modification of the Ca2+ channel gating behaviour as a result of binding of surface amino groups.

[The effect of pH on the passive transport of Ca2+ by membranes of fragmented sarcoplasmic reticulum of skeletal muscles]. / Vliianie pH na passivnyi transport Ca2+ membranami fragmentirovannogo sarkoplazmaticheskogo retikuluma skeletnykh myshts.

The initial rate of Ca2+ translocation in vesicular preparations of the sarcoplasmic reticulum membranes is shown to fall with a pH decrease to 6.0 or 5.0 and to rise with a pH change to 7.0 to 7.8 in respect to the initial 6.5. It is established that the Ca2+ sorption by the membranes or their fluidity make no essential contribution to the recorded changes of 45Ca2+ level in the membrane preparations. It is shown that the passive Ca2+ transport depends to a considerable extent on the concentration of a proton at the outer surface of the sarcoplasmic reticulum membrane: an excess of H+ inhibits the Ca2+ input and output, while a decrease of the proton concentration promotes an increase in the rate of these processes in the sarcoplasmic reticulum.

[Isolation of Ca 2+-activated photoprotein obelin from Obelia longissima and its use for the recording the outflow of Ca 2+ from fragmented sarcoplasmic reticulum of skeletal muscles]. / Poluchenie Ca 2+-aktiviruemogo fotoproteina obelina iz Obelia longissima i ego primenenie dlia registratsii vykhoda Ca 2+ iz fragmentirovannogo sarkoplazmaticheskogo retikuluma skeletnykh myshts.

A high-active stable preparation of obelin has been obtained from the luminescent hydroid Obelia longissima. The preparation is appropriate for determining free Ca2+ in the physiological range of its concentrations Obelin is shown possible to be used to record the processes of Ca2+ release from vesicles of the sarcoplasmic reticulum. In this case a rapid initial phase of Ca2+ outflux replaced by a slower one has been registered. A sharp increase of luminescence caused by the appearance of free Ca2+ in the medium has been registered under the effect of agents either increasing permeability of sarcoplasmic reticulum membranes for Ca2+ (A23187) or destroying the membrane (ethanol, triton X-100). The observed effects are confirmed, a radioactive label being used.

[Intravenous laser irradiation of the blood in occlusive vascular diseases of the extremities]. / Vnutrivennoe lazernoe obluchenie krovi pri obliteriruiushchikh zabolevaniiakh sosudov konechnostei.

The authors analyze the results of clinical application of intravenous He-Ne laser irradiation of the blood in patients with obliterating diseases of the limb vessels. Starting from 1984, this method was employed in the treatment of 133 patients, of these 102 ones with atherosclerosis obliterans of the lower limb vessels, 17 with endarteritis obliterans, and 14 with Raynaud's syndrome. Intravenous laser therapy proved to the most effective in atherosclerotic involvement of the vessels, when positive result was achieved in 77.5 percent of patients. The length of remission was up to 6 months. the method of treatment is described.