Hypolimnion behavior of technetium in freshwater at various stages of eutrophication.

The article presents a study of various mechanisms of hypolimnion technetium behavior which occur at different stages of waterbodies eutrophication. Eutrophication stage was found to be positively correlated with the rate of 99Tc removal from water phase. The study identified a complex biogeochemical mechanism of technetium behavior. Planktonic phototrophic community plays a pivotal role in such a mechanism by ensuring fast oxygen consumption in hypolimnion. This creates favorable conditions for the active development of anaerobic bottom bacteria of sulfur and iron cycles given nutrients inflow. Sulfates and nitrates were discovered to have inhibitory effect on 99Tc biosorption by bottom sediments due to oxidizing conditions. Apart from the shift of redox potential of the medium to reducing values, the 99Tc removal and partial immobilization are also promoted by the presence of inorganic mineral phases of reduced sulfur and iron. These phases form a reducing barrier in the silt, thus preventing the oxidation and migration of technetium. We suggest the ways of stimulating in situ waterbody remediation by means of various additives, which will allow irreversible immobilization of technetium in silt once several growth periods have passed.

Activated carbon additives for technetium immobilization in bentonite-based engineered barriers for radioactive waste repositories.

Safe disposal of nuclear waste in a geologic repository will rely on natural geologic features and engineered barriers to greatly retard the movement of radionuclides from the repository. Clay minerals including bentonite are effective in retarding the migration of many radionuclides, but are ineffective for anionic radionuclides, of which pertechnetate is of particular concern owing to its relatively long half-life and the lack of natural isotopes that dilute it. Activated carbon is proposed as an additive material for reducing pertechnetate mobility in the nearfield. Activated carbon materials of different origins quantitatively sorb pertechnetate from aqueous solution under oxidizing conditions during the first day of contact, and sequential extraction showed that 73 % of this technetium is in the strongly bound fraction. X-ray photoelectron spectra (XPS) and extended X-ray absorption fine structure (EXAFS) spectra both demonstrated that no reduction of technetium occurred in the studied systems. The interaction of technetium with a composite material consisting of bentonite and activated carbon was studied at the first time. Effective technetium sorption was shown, with distribution coefficients (Kd) up to 740 cm3. g-1.

Ballistic trans-urethral resection of the prostate - A case report of gunshot injury to the posterior urethra.

We report a case of penetrating gunshot injury to the posterior urethra sustained by a low-velocity projectile during a civilian drive-by shooting. The bullet passed through the prostatic urethra, missing other vital organs and both the internal and external urethral sphincters. Following a period of urethral catheterisation, the patient made a complete recovery with good continence and sexual function.

[New Radiopharmaceuticals Based on Prostate-Specific Inhibitors of Membrane Antigen for Diagnostics and Therapy of Metastatic Prostate Cancer].

About 10.7% cases of prostate cancer were registered in Russia in 2011 (40,000 patients). More than half of cancer cases were revealed in advanced (III-IV) stages when metastases inevitably developed quickly. Clinical problem of early diagnostics and treatment of metastatic prostate cancer is still not solved. Anatomical imaging techniques have low sensitivity and specificity for the detection of this disease. Metabolic visualization methods which use prostate specific antigen (PSA) as a marker are also ineffective. This article describes prostate-specific membrane antigens (PSMA) that are proposed as a marker for diagnostics and therapy of prostate cancer. The most promising PSMA-based radiopharmaceutical agent for diagnostics has been developed and clinically tested in the European countries. These pharmaceuticals are based on small peptide molecules modified with urea, and have the highest affinity to PSMA. Favorable phannacokinetics, rapid accumulation in the tumor and rapid excretion from the body are beneficial features of these pharmaceuticals.

[Microbiological Aspects of Radioactive Waste Storage].

The article gives information about the microorganisms inhabiting in surface storages of solid radioactive waste and deep disposal sites of liquid radioactive waste. It was shown that intensification of microbial processes can lead to significant changes in the chemical composition and physical state of the radioactive waste. It was concluded that the biogeochemical processes can have both a positive effect on the safety of radioactive waste storages (immobilization of RW macrocomponents, a decreased migration ability of radionuclides) and a negative one (biogenic gas production in subterranean formations and destruction of cement matrix).

Molecular distinctions between pediatric and adult mature B-cell non-Hodgkin lymphomas identified through genomic profiling.

Burkitt lymphoma (BL) predominates in pediatric patients, whereas diffuse large B-cell lymphoma (DLBCL) is uncommon. In contrast to adults, BL and DLBCL are treated similarly in children and both entities have superior outcomes in children compared with adults. Gene expression profiling (GEP) and miRNA expression profiling clearly differentiated pediatric DLBCL from BL, forming distinct clusters regardless of patient age. However, pathway analysis of GEP data identified minor differences between corresponding pediatric and adult tumors. Predominance (6:1) of the germinal center B-cell subtype to activated B-cell subtype was found among pediatric DLBCL. Two cases were molecularly classified as primary mediastinal B-cell lymphoma. We observed frequent abnormalities in 8q24 in pediatric DLBCL, including MYC rearrangement in 31% (5 of 16) and gain or amplification in 50% (6 of 12) nonrearranged cases. MYC rearrangement was present in 96% (23 of 24) BL cases. Array-based CGH analysis identified abnormalities that are shared between adult and pediatric DLBCL (+12q15, +19q13, -6q), and abnormalities unique to the pediatric cases (-4p14, -19q13.32, +16p11.2), suggesting distinct pathogenetic mechanisms relative to age. Elucidation of the underlying target genes may provide insight into factors that modulate outcome and could provide potential novel therapeutic targets with less toxicity for pediatric patients with B-cell non-Hodgkin lymphoma.

Tepidimicrobium ferriphilum gen. nov., sp. nov., a novel moderately thermophilic, Fe(III)-reducing bacterium of the order Clostridiales.

A moderately thermophilic, anaerobic bacterium (strain SB91T) was isolated from a freshwater hot spring at Barguzin Valley, Buryatiya, Russia. Cells of strain SB91T were straight to slightly curved rods, 0.5-0.6 microm in diameter and 3.0-7.0 mum in length. Formation of endospores was not observed. The temperature range for growth was 26-62 degrees C, with an optimum at 50 degrees C. The pH range for growth was 5.5-9.5, with an optimum at pH 7.5-8.0. The substrates utilized by strain SB91T in the presence of 9,10-anthraquinone 2,6-disulfonate included peptone, tryptone, Casamino acids, yeast extract, beef extract, casein hydrolysate, alanine plus glycine, alanine plus proline, L-valine and n-propanol. Carbohydrates were not utilized. Strain SB91T reduced amorphous Fe(III) oxide, Fe(III) citrate, Fe(III) EDTA or Fe(III) nitrilotriacetate with peptone, L-valine or n-propanol as an electron donor. Strain SB91T reduced 9,10-anthraquinone 2,6-disulfonate, thiosulfate, elemental sulfur, fumarate and selenite. Strain SB91T survived after exposure to gamma-radiation at a dose of 5.4 kGy. The G+C content of the DNA of strain SB91T was 33 mol%. Analysis of the 16S rRNA gene sequence revealed that the isolated organism belonged to cluster XII of the clostridia. On the basis of its physiological properties and the results of phylogenetic analyses, it is proposed that strain SB91T represents the sole species of a novel genus, Tepidimicrobium; the name Tepidimicrobium ferriphilum gen. nov., sp. nov. is proposed, with strain SB91T (=DSM 16624T=VKM B-2348T) as the type strain.

Functional coupling between the limbs during bimanual reach-to-grasp movements.

While it is frequently advantageous to be able to use our hands independently, many actions demand that we use our hands co-operatively. In this paper we present two experiments that examine functional binding between the limbs during the execution of bimanual reach-to-grasp movements. The first experiment examines the effect of gaze direction on unimanual and bimanual reaches. Even when subjects' eye movements are restricted during bimanual reaches so that they may only foveate one target object, the limbs remain tightly synchronized to a common movement duration. In contrast, grip aperture is independently scaled to the size of the target for each hand. The second experiment demonstrates however, that the independent scaling of grip aperture is task dependent. If the two target objects are unified so that they appear to be part of a single object, grip apertures become more similar across the hands (i.e., grip aperture to the large target object is reduced in size while peak aperture to the small target item is increased in size). These results suggest that the coupling of the limbs can operate at a functional level.

The role of ureter in the creation of Mitrofanoff channels in children.

PURPOSE: Since 1980 numerous variations of the Mitrofanoff principle have been described. We report on 22 children in whom a ureteral Mitrofanoff channel was created. MATERIALS AND METHODS: Between 1986 and 1995 a ureteral Mitrofanoff channel was constructed as a catheterizable conduit in 22 children 2 to 15 years old (average age 6.5) with various abnormalities of the lower urinary tract, mainly exstrophy and neurogenic bladder. Indications included unavailability or unsuitability of the appendix, preference for appendix as a catheterizable colonic stoma for antegrade washouts or concomitant removal of a nonfunctioning kidney, leaving the ureter available for use. Surgical technique was based on the principles of appendicovesicostomy and in 9 cases the ureteral Mitrofanoff channel was reimplanted. RESULTS: Followup ranged from 1 to 72 months (average 30.5). Complications included stenosis of the conduit that caused difficult catheterization in 3 patients, necessitating dilation or minor revision in 2 and complete replacement by appendix in 1. Urinary leakage from the Mitrofanoff channel in 5 patients was treated with polydimethylsiloxane injection or oxybutinin. In 1 patient the channel was reimplanted, since the catheter struck the bladder neck during catheterization and caused severe pain. CONCLUSIONS: Results of the ureteral Mitrofanoff channel seem somewhat less satisfactory than those of appendicovesicostomy but they remain acceptable and even comparable, strongly supporting its use in certain circumstances.

A randomized cross-over study comparing the use of a catheter valve and a leg-bag in urethrally catheterized male patients.

OBJECTIVES: To evaluate the use of a catheter valve (CV) and a leg-bag (LB) in men with urethral catheters and to determine the preferred modality. PATIENTS AND METHODS: Eighteen men (mean age 71.4 years, SD 3.4, range 63-76) presenting in acute retention and catheterized urethrally were enrolled in a 6-week randomized cross-over study comparing the CV with the LB (3 weeks with each modality). The outcome was assessed using a questionnaire which quantified the incidence of bladder spasms, nocturnal frequency, the extent of any by-passing episodes and the degree of discomfort. At the end of the study, the patients were asked to express a preference (using a subjective scoring scale) for either the CV or the LB and to give the reasons why. RESULTS: There was no difference in the reported incidence of bladder spasms or discomfort and no difference in positive urine cultures with each modality. However, with the CV, there was a slightly higher incidence in nocturnal frequency and by-passing episodes. Thirteen patients preferred the CV whilst five preferred the LB. With the subjective scoring scale (range 0-10), the CV scored significantly higher than the LB (7.2, SD 3.1 and 5.2, SD 2.8, P < 0.05: paired t-test). CONCLUSIONS: Most patients preferred to use the CV, reporting that it felt more comfortable and discreet, and many patients did not like the sensation of urine 'sloshing about' when using the leg-bag. Some patients using the CV were troubled by nocturnal frequency. In these patients we suggest that a combination of a valve during the day and an overnight bag may be the ideal solution.

Comparison of relaxation responses of detrusor strips from neuropathic and control patients.

OBJECTIVES: To confirm the existence of relaxation responses to electrical-field stimulation in strips of human detrusor, and to compare these responses in strips from control subjects with those in strips from a group of neuropathic patients exhibiting hyperreflexia. PATIENTS AND METHODS: Detrusor specimens were obtained at operation from a group of control patients, and from a group of patients with neuropathy (mainly spina bifida) and a history of hyper-reflexia. Muscle strips were prepared from these, mounted in organ baths, and contracted by exposure to a modified Krebs' solution containing 26 mM KCl and atropine. Relaxation responses were induced by an electrical-field stimulation (50 V, 90 microsecond pulses at 2-16 Hz for 10 s). RESULTS: Of 29 strips, 20 (69%) from control patients showed relaxations, compared with 17 of 28 strips (61%) from neuropathic patients (P > 0.1). The maximum relaxation response in the control strips was 49 +/- 5.6% (mean +/- SEM) of the maximum relaxation induced by isobutyl methylxanthine, compared with 43 +/- 4.8% in the strips from neuropathic patients (P > 0.1). The maximum response occurred at similar frequencies (4 or 8 Hz) in the two groups. The relaxations were reduced by the inhibitor of nitric oxide synthase, N-nitro L-arginine methyl ester (0.1 mM, P < 0.05), but were not affected by guanethidine (50 microM) or tetrodotoxin (0.5 microM). CONCLUSION: These results confirm the existence of field stimulation-induced relaxation in human detrusor, but suggest that hyper-reflexia in the neuropathic bladder cannot be accounted for by any deficiency in this response.

Physiological and morphometric studies into the pathophysiology of detrusor hyperreflexia in neuropathic patients.

The in vitro responses of isolated detrusor strips obtained from neuropathic patients with neuropathic bladder dysfunction were found to be supersensitive to both carbachol [ED50 1.2 x 10(-6) M. versus 2.5 x 10(-6) M. in control strips; p < 0.005] and potassium chloride [ED50 41.8 mM. versus 49.3 mM. in control strips, p < 0.05]. There were no significant differences in the frequency-response curves obtained with intramural nerve stimulation. However, expressed as a percentage of the maximal response with carbachol, the maximal responses to intramural nerve stimulation in neuropathic strips were reduced [58.3 +/- 21% versus 74.4 +/- 18% for control strips; p < 0.005, Student t test]. Morphometric studies revealed a lower density of 'presumptive' cholinergic nerves in neuropathic detrusor (1.0 +/- 1.4 x 10(-4) microns -2 compared with 3.2 +/- 1.3 x 10(-4) microns -2 in controls, p < 0.05, Mann Whitney U test). The combined physiological and morphometric results were in keeping with a state of postjunctional supersensitivity of neuropathic detrusor secondary to a partial parasympathetic denervation of the smooth muscle. This may be an important factor in the etiology of detrusor hyperreflexia. The contractility of neuropathic tissue in response to field stimulation was found to be much lower than normal (2.4 +/- 1.5 g./10 mg. versus 5.9 +/- 3.0 g./10 mg., p < 0.001; Mann Whitney U test). This reduced contractility to neuronal stimulation might be responsible for some of the characteristics of bladder dysfunction that are seen in patients with similar neurological conditions.