Distinct magnetic phase transition at the surface of an antiferromagnet.

In the majority of magnetic systems the surface is required to order at the same temperature as the bulk. In the present Letter, we report a distinct and unexpected surface magnetic phase transition at a lower temperature than the Néel temperature. Employing grazing incidence x-ray resonant magnetic scattering, we have observed the near-surface behavior of uranium dioxide. UO2 is a noncollinear, triple-q, antiferromagnet with the U ions on a face-centered cubic lattice. Theoretical investigations establish that at the surface the energy increase-due to the lost bonds-is reduced when the spins near the surface rotate, gradually losing their component normal to the surface. At the surface the lowest-energy spin configuration has a double-q (planar) structure. With increasing temperature, thermal fluctuations saturate the in-plane crystal field anisotropy at the surface, leading to soft excitations that have ferromagnetic XY character and are decoupled from the bulk. The structure factor of a finite two-dimensional XY model fits the experimental data well for several orders of magnitude of the scattered intensity. Our results support a distinct magnetic transition at the surface in the Kosterlitz-Thouless universality class.

Bell clapper testis, torsion, and detorsion: a case report.

We are presenting a common but interesting case of testicular torsion. Torsion is a common important urological emergency. History and examination is important for diagnosis. Urgent testicular exploration is an important message if in doubt.

Thulium: YAG 2 mum cw laser prostatectomy: where do we stand?

INTRODUCTION: Tm:YAG 2 mum cw laser prostatectomy was introduced in the treatment of benign ptostatic obstruction (BPO). Since then numerous studies have been published proving efficacy during follow-up. However, different surgical techniques were introduced with different names for similar techniques that complicate comparison. This reviews aim was to compare published data and break down surgical techniques to core points. The authors define validate appellations for different surgical techniques and propose further use of these names to ensure homogenous nomenclature. MATERIALS AND METHODS: All publications on Thulium:YAG prostatectomy have been included in this review. Articles were reviewed and associated due to the nature of the surgical approach. A systematic review of published data was performed. RESULTS: Sixteen peer-reviewed publications dealing with Tm:YAG laser prostatectomy were printed since 2005. Four different surgical principles are described, including vaporization, resection and enucleation. Follow-up, up to 24 months, showed durable functional results. CONCLUSION: Efficacy of Tm:YAG prostatectomy was shown. Surgical techniques include "Tm:YAG Vaporization of the prostate (ThuVAP)", "Tm:YAG VapoResection of the prostate (ThuVaRP)" and "Tm:YAG VapoEnucleation of the prostate (ThuVEP)". The almost blunt enucleation is introduced as "Tm:YAG laser enucleation of the prostate (ThuLEP)". The authors recommend the use of this neologism in the future. Further, large-scale prospective studies are needed to prove long-term durability. To initiate and canalize these upcoming studies, the Urothulium Study Group was founded, combining international experts on Thulium:YAG laser prostatectomy under its roof.

Detecting a field gradient of PAH exposure in decapod crustacea using a novel urinary biomarker.

Norwegian coastal waters are subject to PAH contamination from electrochemical industries such as aluminium smelters. Evidence of PAH exposure has been established in fish and bivalves. The present study tests the applicability of a novel crustacean PAH exposure biomarker to a PAH contamination gradient in the field (Karmsund Strait, SW Norway). Fluorescence analysis of urine samples collected from crabs at each site revealed 1-OH pyrene "equivalent" levels (indicative of pyrogenic PAH contamination) decreased with increasing distance from a point source of pyrogenic PAH (a large aluminium works). The assay was shown to be suitable for the detection of PAH exposure in wild crustacean populations, for discriminating between contaminated and clean sites and is also sufficiently sensitive to detect gradients of PAH contamination. The method provides a rapid, inexpensive and non-destructive measure of biologically available PAH in crustaceans.

A non-destructive assessment of the exposure of crabs to PAH using ELISA analyses of their urine and haemolymph.

Urine and haemolymph can be repeatedly sampled from crabs with no (or limited) damage to the organism. Their analysis offers a measure of the animals' exposure to biologically available contaminants. Shore crabs (Carcinus maenas) were exposed to the PAHs phenanthrene and pyrene at concentrations ranging from 20 to 200 microg l(-1). After 48 h, urine and haemolymph samples were taken and analysed using ELISA and UV-fluorescence spectrophotometry. High correlations were recorded between the two sets of results from the urine analyses (r2 = 0.83 for phenanthrene and r2 = 0.88 for pyrene). Contaminant concentrations were much lower in haemolymph than in the urine. Analyses of urine taken from crabs collected from clean and contaminated sites confirm the suitability of these analyses for environmentally exposed organisms. Again, a good correlation was recorded between the ELISA and spectrofluorimetric analysis (r2 = 0.83). In this instance, difficulties were experienced with haemolymph analyses owing to a lack of sensitivity.

Trimethoprim versus gentamicin for the prevention of bacteriuria following transrectal biopsy of the prostate--do patients need additional anaerobic cover?

OBJECTIVES: To study the incidence of aerobic and anaerobic bacteriuria in patients undergoing transrectal ultrasound-guided biopsies of the prostate. A comparative assessment of efficacy of trimethoprim with gentamicin for the prevention of bacteriuria following the transrectal biopsy of the prostate. To assess the need for additional prophylaxis against anaerobes for patients undergoing transrectal biopsies of the prostate gland. PATIENTS AND METHODS: In a pilot study during 1995-1997, all the patients undergoing transrectal ultrasound-guided biopsy of the prostate were randomised to receive either trimethoprim or gentamicin prophylaxis prior to the procedure. Midstream urine (MSU) samples were taken just prior to biopsy and 72 h later. A patient questionnaire to determine the symptoms of urinary tract infection (UTI) accompanied the 72-hour MSU request form. Urine samples were cultured aerobically, using a semiquantitative technique if dipstick analysis revealed the presence of blood, pus cell or nitrite. In addition to the routine aerobic culture, post-biopsy samples were also cultured for anaerobes by direct and enrichment methods. Bacteriuria was defined as a pure or mixed growth of 10(5) colony-forming units/ml. Fisher's test of exact probability was used for statistical analysis. RESULTS: 115 patients were available for final analysis. 53 had received gentamicin and 62 trimethoprim. Four patients had pre-existing bacteriuria (3.5%), 3 in the trimethoprim group and 1 in the gentamicin group. Post-operative bacteriuria developed in 5 patients given gentamicin (9.4%) and 1 given trimethoprim (1.6%). This difference was not statistically significant (p = 0.085). Post-procedure bacteriuria was asymptomatic in all but 1 case. Anaerobes were detected in only 5 MSUs (4.3%) post-biopsy. CONCLUSION: Though there was no statistical significant difference in the rates of bacteriuria following administration of trimethoprim and gentamicin, data appear to favour trimethoprim prophylaxis. Further studies are warranted. Transrectal biopsy of the prostate is associated with a low incidence of anaerobic UTI. In view of the very low incidence of anaerobic bacteriuria, routine antibacterial prophylaxis against anaerobes does not appear to be justified.

Uterine artery embolisation for the treatment of symptomatic fibroids in 114 women: reduction in size of the fibroids and women's views of the success of the treatment.

OBJECTIVE: To assess the reduction in size of fibroids following uterine artery embolisation and to analyse women's views of the success of treatment. DESIGN: An uncontrolled case series of 114 consecutive women who underwent uterine artery embolisation for the treatment of fibroids over two years. SETTING: The Diagnostic and Interventional Radiology Department at The Royal Surrey County Hospital, Guildford, UK. METHODS: Bilateral uterine artery embolisation was performed for the treatment of symptomatic fibroids. Magnetic resonance imaging was carried out before and six months following embolisation. Women completed outcome questionnaires following their treatment. MAIN OUTCOME MEASURES: The sites. imaging signal characteristics and percentage reduction in the volume of three dominant fibroids were determined from the magnetic resonance scans. Outcome was measured by questionnaire. Women were asked whether their symptoms resolved completely, improved, remained unchanged or deteriorated. RESULTS: One hundred and sixty-five fibroids of 114 women (mean age 42) were analysed. Forty-five percent of women had complex fibroid masses and 50% had fibroids > or =8.5cm in diameter. The median reduction in the fibroid volume was 58%. The median reduction of the volume of complex fibroid masses, submucous fibroids, fibroids > or =8.5cm and fibroids with high and low signal on T2 weighted sequences were 58%, 63%, 50%, 62% and 51%, respectively. Ninety-one percent of the women's symptoms had resolved or improved following embolisation. DISCUSSION: The majority of women were satisfied with their outcome. We have shown that uterine artery embolisation is a successful treatment for symptomatic fibroids of all types, sizes and signal characteristics.

Primary antegrade ureteric stenting: prospective experience and cost-effectiveness analysis in 50 ureters.

AIM: To evaluate the success rate and cost efficiency of primary antegrade ureteric stenting (antegrade ureteric stent insertion as a single procedure without preliminary drainage). MATERIALS AND METHODS: A policy of primary stenting was tested in 38 patients (50 ureters) with obstructive hydronephrosis, of acute or chronic onset and of benign or malignant origin. Patients with suspected pyonephrosis were excluded. Patients successfully primarily stented (group 1) were compared to a group stented as a traditional two-stage procedure (group 2). End point assessments were screening time, equipment used, procedure-related costs, bed occupancy and technical and clinical success rate. Using these cost and outcome measures, a cost-efficiency analysis was performed comparing the two strategies. RESULTS: 40/50 (80%) ureters were considered primary stent successes. The average procedure-related bed occupancy was 2 days (range 1-2 days). Simple equipment alone was successful in 16 cases. Van ( pound46/case). The mean screening time was similar for the two groups (13.5 min vs Andel dilatation catheters and peel-away sheaths were frequently used (23 ureters). Expensive equipment was rarely necessary (four cases) and average extra equipment cost was small 15.3 min; P > or = 0.05). There was a minimum saving of pound800 per successful primary stent. The cost-effectiveness of a primary antegrade stenting strategy was pound1229 vs pound2093 for secondary stenting. CONCLUSION: In carefully selected patients, the majority of obstructed ureters can be primarily stented using simple equipment. The reduced hospital stay and overall success rate significantly improves the cost competitiveness of antegrade ureteric stenting.

Anemone repair proteins as a potential therapeutic agent for vertebrate hair cells: facilitated recovery of the lateral line of blind cave fish.

Blind cave fish use the lateral line sensory system to detect nearby objects. The fish responds to sudden perturbations in the water column by initiating startle responses in which they swim more rapidly. Normal startle responses disappear after trauma caused by a single 15 s immersion in calcium free water, but return within 5 days if the traumatized fish are treated with 'repair proteins' isolated from sea anemones. Polyclonal antibodies raised to fraction beta, a specific chromatographic fraction of repair proteins, bind to hair cells within superficial neuromasts. Likewise, biotinylated fraction beta binds to hair cells in neuromasts. Neuromast hair cells exposed to calcium free water followed by repair proteins have more compact hair bundles than do hair cells exposed only to calcium free water. We propose that anemone repair proteins replace linkages between stereocilia destroyed by exposure to calcium free water.

Reorganization of actin during repair of hair bundle mechanoreceptors.

Hair bundle mechanoreceptors can be damaged by over-stimulation or by exposure to calcium-free buffers. Provided the trauma is slight, hair bundles recover, although the subcellular mechanisms for such recovery are poorly understood. Hair bundle mechanoreceptors on tentacles of sea anemones are especially resilient, recovering from severe trauma within several hours. During the recovery period, large protein complexes are secreted called "repair proteins" containing replacement linkages for those lost during trauma. In the present study, we find that recovery requires reorganization of the actin-based cytoskeleton in hair bundles. F-actin is first partially depolymerized and then repolymerized in hair bundles based on confocal microscopy. Furthermore, stereocilia show considerable motility during repair based on field emission scanning electron microscopy of hair bundles fixed at 1 min intervals after exposure to exogenously supplied repair protein complexes. Recovery of vibration sensitivity occurs at the organismal level within 8 min. Paradoxically, a full recovery of morphology of hair bundles requires approximately 45 min and a recovery of F-actin levels requires approximately 40 min. Similarly, a full recovery of mechanoelectric responses of hair cells requires approximately 45 min. Thus, it appears that the recovery of responsiveness at the organismal level precedes a full recovery of hair bundles.

Immunological evidence that anemone repair proteins include replacement linkages.

In response to damage to hair bundles caused by exposure to calcium free buffers, sea anemones secrete large protein complexes named 'repair proteins' that rapidly restore structural integrity and function to hair bundles. A specific chromatographic fraction of the repair protein mixture, named 'fraction beta', has biological activity comparable to the complete repair protein mixture (Watson et al., 1998, Hear. Res. 115, 119-128). In this study, we find that polyclonal antibodies raised against deglycosylated fraction beta specifically bind fraction beta on Western blots. Anti-fraction beta delays the normal recovery of vibration sensitivity in experimental animals (i.e., those with hair bundles damaged by calcium free buffers). Moreover, anti-fraction beta disrupts vibration sensitivity in control animals (i.e., those with healthy hair bundles). Experimentally damaged hair bundles subsequently exposed to repair protein and then processed for immunoelectron microscopy show labeled linkages interconnecting stereocilia of the hair bundle. Immunofluorescence microscopy confirms strong labeling of hair bundles treated with repair proteins and only weak labeling of tips of hair bundles from control animals. Immunofluorescence microscopy indicates stores of repair proteins in gland cells of the body column in control animals and in gland cells of the mouth in experimental animals. Repair biological activity is confirmed in column purified homogenates of these tissues. Apparently repair proteins are delivered to damaged hair bundles in mucus carried by beating cilia.

Rhythmic sensitization of nematocyst discharge in response to vibrational stimuli.

Sea anemones capture prey by discharging nematocysts and other cnidae. Discharge of microbasic p-mastigophore (mpm) nematocysts is regulated in part by hair bundle mechanoreceptors on tentacles arising from multicellular complexes consisting of supporting cells and a sensory neuron. Anemone hair bundles detect movements of prey and then sensitize cnidocytes (cnida-containing cells) to discharge mpm nematocysts in response to contact between the prey and tentacle. Data from a simple bioassay based on counting nematocysts discharged into test probes, indicate that approximately twice as many nematocysts discharge into test probes touched to tentacles after sensitization than before sensitization. We here report that sub-second bursts of vibrational stimuli at key frequencies (51, 55, 65, or 74 Hz; Watson GM, Mire P, Hudson RR. 1998. J Exp Zool 281:582-593) sensitize discharge for at least 90 sec. Very few complete cycles of vibration are sufficient to sensitize discharge. However, as the number of cycles of vibration is increased, discharge is sensitized in rhythmic patterns. Computer analysis of the data by fast Fourier transforms indicates discharge to vibrations at 65 Hz is sensitized every 6.75 cycles. At 51 Hz discharge is sensitized every 2.00 cycles. At 74 Hz, discharge is sensitized in a polyrhythm occurring every 4.26, 3.76, 2.46, and 2. 10 cycles, respectively. At 55 Hz, discharge is sensitized in a polyrhythm occurring every 6.09, 3.20, 2.91, and 2.0 cycles, respectively. Apparently, cells in the neuronal pathway interconnecting anemone hair bundles with cnidocytes count cycles of vibration and then sensitize discharge or not according to the tally. J. Exp. Zool. 286:262-269, 2000.

Does endoscopic laser ablation of the prostate stand the test of time? Five-year results from a multicentre randomized controlled trial of endoscopic laser ablation against transurethral resection of the prostate.

OBJECTIVE: To determine the long-term objective and subjective outcome of patients with benign prostatic enlargement (BPE) treated by endoscopic laser ablation of the prostate (ELAP), as part of a multicentre randomized controlled trial of ELAP against TURP. PATIENTS AND METHODS: Initially, 151 patients with BPE were randomized to undergo either ELAP or TURP, starting in March 1992. ELAP was performed using the Urolasetrade mark fibre (Bard, Covington, GA, USA) in conjunction with a Nd:YAG laser source. All patients who had originally participated in the study were approached 5 years later to obtain a urological history, American Urological Association (AUA) symptom score and two measurements of urinary flow rate, with an ultrasonographic assessment of the postvoid residual urine volume (PVR). RESULTS: The mean duration of follow-up was 61 months; 109 patients were traced, comprising 69 who were alive and well, and had undergone no further bladder outlet surgery, 26 who had required revision surgery, 12 who were dead or terminally ill and three who had dementia. Both ELAP and TURP produced sustained improvements in mean AUA score, maximum flow rate and PVR, with respective values at 5 years of 6.3, 17.8 mL/s and 76 mL, and 6.5, 20.0 mL/s and 55 mL. Eighteen of 47 ELAP patients (38%) and eight of 51 (16%) TURP patients underwent revision surgery within the follow-up. CONCLUSION: ELAP and TURP produced similar subjective and objective outcomes at 5 years. The re-operation rate after ELAP was more than double that after TURP and suggests that ELAP should not be used routinely in the management of men with BPE.

ATP enhances repair of hair bundles in sea anemones.

Hair bundle mechanoreceptors of sea anemones are similar to those of the acousticolateralis system of vertebrates (Watson, Mire and Hudson, 1997, Hear. Res. 107, 53-63). Anemone hair bundles are repaired by 'repair proteins' secreted following a complete loss of structural integrity and loss of function caused by 1 h exposure to calcium free seawater. Exogenously supplied repair proteins (RP) restore structural integrity to hair bundles and restore vibration sensitivity in 7-8 min (Watson, Mire and Hudson, 1998, Hear. Res. 115, 119-128). We here report that exogenously supplied ATP enhances the rate by which RP restore vibration sensitivity. A bimodal dose response to ATP indicates maximal enhancement at picomolar and micromolar concentrations of ATP. At these concentrations of ATP, vibration sensitivity is restored in 2 min. These data suggest that at least two ATPases exhibiting different binding affinities for ATP are involved in the repair process. Whereas the higher affinity site is specific for ATP, the lower affinity site does not discriminate between ATP and ADP. Nucleotidase cytochemistry localizes ATPase activity in isolated repair proteins. In the absence of exogenously added RP, sea anemones secrete and consume ATP during the 4 h recovery period after 1 h exposure to calcium free seawater. In the presence of exogenously added RP, ATP is secreted and then consumed within 10 min. Quinacrine cytochemistry localizes possible stores of ATP in the apical cytoplasm of sensory neurons located at the center of the hair bundle. According to our model, ATP is secreted by the sensory neuron after its hair bundle loses structural integrity. Hydrolysis of ATP by repair proteins is essential to the repair process.