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A method for characterizing the topological fluctuations in liquids is proposed. This approach exploits the concept of the weighted gyration tensor of a collection of particles and permits the definition of a local configurational unit (LCU). The first principal axis of the gyration tensor serves as the director of the LCU, which can be tracked and analyzed by molecular dynamics simulations. Analysis of moderately supercooled Kob-Andersen mixtures suggests that orientational relaxation of the LCU closely follows viscoelastic relaxation and exhibits a two-stage behavior. The slow relaxing component of the LCU corresponds to the structural, Maxwellian mechanical relaxation. Additionally, it is found that the mean curvature of the LCUs is approximately zero at the Maxwell relaxation time with the Gaussian curvature being negative. This observation implies that structural relaxation occurs when the configurationally stable and destabilized regions interpenetrate each other in a bicontinuous manner. Finally, the mean and Gaussian curvatures of the LCUs can serve as reduced variables for the shear stress correlation, providing a compelling proof of the close connection between viscoelastic relaxation and topological fluctuations in glass-forming liquids.
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While glasses are ubiquitous in natural and manufactured materials, the atomic-level mechanisms governing their deformation and how these mechanisms relate to rheological behavior are still open questions for fundamental understanding. Using atomistic simulations spanning nearly 10 orders of magnitude in the applied strain rate we probe the atomic rearrangements associated with 3 characteristic regimes of homogeneous and heterogeneous shear flow. In the low and high strain-rate limits, simulation results together with theoretical models reveal distinct scaling behavior in flow stress variation with strain rate, signifying a nonlinear coupling between thermally activated diffusion and stress-driven motion. Moreover, we find the emergence of flow heterogeneity is closely correlated with extreme values of local strain bursts that are not readily accommodated by immediate surroundings, acting as origins of shear localization. The atomistic mechanisms underlying the flow regimes are interpreted by analyzing a distance matrix of nonaffine particle displacements, yielding evidence of various barrier-hopping processes on a fractal potential energy landscape (PEL) in which shear transformations and liquid-like regions are triggered by the interplay of thermal and stress activations.
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Molecular processes of creep in metallic glass thin films are simulated at experimental timescales using a metadynamics-based atomistic method. Space-time evolutions of the atomic strains and nonaffine atom displacements are analyzed to reveal details of the atomic-level deformation and flow processes of amorphous creep in response to stress and thermal activations. From the simulation results, resolved spatially on the nanoscale and temporally over time increments of fractions of a second, we derive a mechanistic explanation of the well-known variation of creep rate with stress. We also construct a deformation map delineating the predominant regimes of diffusional creep at low stress and high temperature and deformational creep at high stress. Our findings validate the relevance of two original models of the mechanisms of amorphous plasticity: one focusing on atomic diffusion via free volume and the other focusing on stress-induced shear deformation. These processes are found to be nonlinearly coupled through dynamically heterogeneous fluctuations that characterize the slow dynamics of systems out of equilibrium.
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PURPOSE: To test the psychometric properties of the International Prostate Symptom Score (Hong Kong Chinese version 2) (IPSS) in Chinese male patients with benign prostatic hyperplasia (BPH) under secondary care. METHODS: A prospective longitudinal study was done by interviewing subjects at baseline, at 2 week after baseline for assessing test-retest reliability and at 26 week after baseline for assessing responsiveness. All subjects were interviewed to complete a structured questionnaire including IPSS, Short Form-12 Health Survey version 2 (SF-12v2) and Depression Anxiety Stress Scale (DASS). RESULTS: The IPSS HRQOL score had weak correlations with SF-12v2 summary and DASS domain scores. For reliability analysis, Cronbach's alpha coefficient was 0.90 for the seven symptom-related items. The intraclass correlation coefficients of the IPSS total symptom score and HRQOL score were 0.90 and 0.86, respectively. For sensitivity, statistically significant differences were detected between the subjects with BPH and those without for IPSS total symptom score (effect size = 0.68) but not the IPSS HRQOL score. The areas under ROC curves for the IPSS total symptom and HRQOL scores were 0.67 and 0.60, respectively. CONCLUSIONS: The IPSS was valid, reliable instrument in Chinese patients with BPH. The IPSS total symptom score, but not the HRQOL score, is sensitive in differentiating subgroups.
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Encuestas Epidemiológicas , Hiperplasia Prostática/psicología , Calidad de Vida , Anciano , Ansiedad/complicaciones , Estudios de Casos y Controles , Depresión/complicaciones , Hong Kong , Humanos , Estudios Longitudinales , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Hiperplasia Prostática/complicaciones , Hiperplasia Prostática/fisiopatología , Psicometría , Reproducibilidad de los Resultados , Estrés Psicológico/complicacionesRESUMEN
Strength and other mechanical properties of cement and concrete rely upon the formation of calcium-silicate-hydrates (C-S-H) during cement hydration. Controlling structure and properties of the C-S-H phase is a challenge, due to the complexity of this hydration product and of the mechanisms that drive its precipitation from the ionic solution upon dissolution of cement grains in water. Departing from traditional models mostly focused on length scales above the micrometer, recent research addressed the molecular structure of C-S-H. However, small-angle neutron scattering, electron-microscopy imaging, and nanoindentation experiments suggest that its mesoscale organization, extending over hundreds of nanometers, may be more important. Here we unveil the C-S-H mesoscale texture, a crucial step to connect the fundamental scales to the macroscale of engineering properties. We use simulations that combine information of the nanoscale building units of C-S-H and their effective interactions, obtained from atomistic simulations and experiments, into a statistical physics framework for aggregating nanoparticles. We compute small-angle scattering intensities, pore size distributions, specific surface area, local densities, indentation modulus, and hardness of the material, providing quantitative understanding of different experimental investigations. Our results provide insight into how the heterogeneities developed during the early stages of hydration persist in the structure of C-S-H and impact the mechanical performance of the hardened cement paste. Unraveling such links in cement hydrates can be groundbreaking and controlling them can be the key to smarter mix designs of cementitious materials.
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PURPOSE: We assessed whether weight reduction is an effective intervention for the management of lower urinary tract symptoms (LUTS) and investigated the relationship between obesity and LUTS. MATERIALS AND METHODS: This was a prospective randomized controlled trial that enrolled obese men older than 50 years with LUTS. The study period was 52 weeks. All patients received standardized alpha-adrenergic blocker therapy for the treatment of benign prostatic hyperplasia (BPH) during the run-in period. Patients were randomized to receive either a standardized prerecorded video program on the general principle of weight reduction or a comprehensive weight reduction program. Patients were assessed at different time points with symptom assessment, uroflowmetry, transrectal ultrasound, and metabolic assessment. RESULTS: Sixty-five patients were allocated to each study arm. After the study period, no significant difference in weight reduction was found between the two arms. When the pre- and postintervention parameters were compared, none were statistically different between the 2 arms, namely nocturia, International Prostate Symptom Score, quality of life assessment, and uroflowmetry parameters. When the whole study population was taken as a single cohort, these parameters were also not significantly different between the group with a body mass index of 25 to <30 kg/m(2) and the group with a BMI of 30 to 35 kg/m(2). CONCLUSIONS: We found no association between obesity and LUTS. This could have been due to the less marked weight difference in our cohort. Whereas weight reduction may be an effective measure to improve LUTS, the implementation of a successful program remains a challenge.
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Antagonistas Adrenérgicos alfa/uso terapéutico , Síntomas del Sistema Urinario Inferior/tratamiento farmacológico , Obesidad , Hiperplasia Prostática/tratamiento farmacológico , Pérdida de Peso , Anciano , Índice de Masa Corporal , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Hiperplasia Prostática/diagnóstico , Calidad de Vida , Índice de Severidad de la Enfermedad , Resultado del TratamientoRESUMEN
This paper presents an extension of the autonomous basin climbing (ABC) method, an atomistic activation-relaxation technique for sampling transition-state pathways. The extended algorithm (ABC-E) allows the sampling of multiple transition pathways from a given minimum, with the additional feature of identifying the pathways in the order of increasing activation barriers, thereby prioritizing them according to their importance in the kinetics. Combined with on-the-fly kinetic Monte Carlo calculations, the method is applied to simulate the anisotropic diffusion of point defects in hcp Zr. Multiple migration mechanisms are identified for both the interstitials and vacancies, and benchmarked against results from other methods in the literature. The self-interstitial atom (SIA) diffusion kinetics shows a maximum anisotropy at intermediate temperatures (400~700 K), a non-monotonic behavior that we explain to originate from the stabilities and migration mechanisms associated with different SIA sites. The accuracy of the ABC-E calculations is validated, in part, by the existing results in the literature for point defect diffusion in hcp Zr, and by benchmarking against analytical results on a hypothetical rough-energy landscape. Lastly, sampling prioritization and computational efficiency are demonstrated through a direct comparison between the ABC-E and the activation relaxation technique.
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Gels of calcium-silicate-hydrates (C-S-H) are the glue that is largely responsible for the mechanical properties of cement. Despite their practical relevance, their nano-scale structure and mechanics are still mainly unexplored, because of the difficulties in characterizing them in a complex material like cement. We propose a colloidal model to investigate the gel mechanics emerging in the critical range of length-scales from several tens to hundreds of nanometers. We show that the size polydispersity of the hydrates and size-dependent effective interactions can explain the mechanical heterogeneities detected in nano-indentation experiments. We also show how these features control the arising of irreversible structural rearrangements under deformation, which are good candidates as nano-scale mechanisms underlying mechanical aging and slow structural relaxation in the gels.
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Probing the mechanisms of defect-defect interactions at strain rates lower than 10(6) s(-1) is an unresolved challenge to date to molecular dynamics (MD) techniques. Here we propose an original atomistic approach based on transition state theory and the concept of a strain-dependent effective activation barrier that is capable of simulating the kinetics of dislocation-defect interactions at virtually any strain rate, exemplified within 10(-7) to 10(7) s(-1). We apply this approach to the problem of an edge dislocation colliding with a cluster of self-interstitial atoms (SIAs) under shear deformation. Using an activation-relaxation algorithm [Kushima A, et al. (2009) J Chem Phys 130:224504], we uncover a unique strain-rate-dependent trigger mechanism that allows the SIA cluster to be absorbed during the process, leading to dislocation climb. Guided by this finding, we determine the activation barrier of the trigger mechanism as a function of shear strain, and use that in a coarse-graining rate equation formulation for constructing a mechanism map in the phase space of strain rate and temperature. Our predictions of a crossover from a defect recovery at the low strain-rate regime to defect absorption behavior in the high strain-rate regime are validated against our own independent, direct MD simulations at 10(5) to 10(7) s(-1). Implications of the present approach for probing molecular-level mechanisms in strain-rate regimes previously considered inaccessible to atomistic simulations are discussed.
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Ensayo de Materiales/métodos , Modelos Teóricos , Simulación de Dinámica Molecular , Estrés Mecánico , Circonio/química , AlgoritmosAsunto(s)
Modelos Químicos , Frío , Simulación por Computador , Vidrio/química , Dióxido de Silicio , Temperatura , ViscosidadRESUMEN
An abrupt increase of the yield stress at sufficiently high strain rate, seen in glassy as well as crystalline structures, signifies a transition from classical thermal fluctuation to stress activated processes. For crystals this behavior has been recently explained using transition-state-theory with a stress-dependent activation barrier for dislocation glide. An equivalent approach, developed independently for amorphous solids, suggests the physical basis of the upturn behavior of the yield stress is more general. Insights into the interplay between thermal and stress activation processes can contribute to the current efforts toward identifying materials science frontiers at the mesoscale.
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Understanding the stability and reactivity of iron sulfide phases is key to developing predictive capabilities for assessing their corrosion and catalytic activity. The differences between the free surface and the bulk interior of such phases are of particular importance in this context. Here, we employ density functional theory to investigate the formation energetics and electronic structure of intrinsic Fe and S vacancies in bulk pyrite (FeS(2)) and on the pyrite (100) surface. The formation energies of intrinsic bulk vacancies of all charge states are found to be high, ranging from 1.7 to 3.7 eV. While the formation energies of surface vacancies are lower, varying from 1.4 to 2.1 eV for S vacancies and from 0.3 to 1.7 eV for Fe vacancies, they are too large to result in significant sub-stoichiometry in bulk pyrite at moderate temperatures. On the basis of charged defect formation energies and defect equilibria calculations, intrinsic charge carriers are expected to outnumber point defects by several orders of magnitude, and therefore, pure pyrite is not expected to demonstrate p-type or n-type conductivity. The presence of surface states is observed to cause a reduction in the band gap at the (100) surface, which was captured computationally and experimentally using tunneling spectroscopy measurements in this work. The vacancy-induced defect states behave as acceptor-like or donor-like defect states within the bulk band gap. The findings on the stoichiometry and the electronic structure of active sites on the (100) surface have important implications for the reactivity of pyrite.
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Compuestos Férricos/química , Física/métodos , Sulfuros/química , Cristalización , Conductividad Eléctrica , Electrónica , Hierro/química , Modelos Químicos , Modelos Estadísticos , Conformación Molecular , Programas Informáticos , Análisis Espectral/métodos , Propiedades de Superficie , TemperaturaRESUMEN
OBJECTIVES: To report the results of a modified vaporisation incision technique using a GreenLight High Performance System in the treatment of benign prostatic disease in men receiving anticoagulants. DESIGN: Case series. SETTING: Regional hospital, Hong Kong. PATIENTS: From January 2007 to April 2010, 48 patients with a bleeding tendency or on oral anticoagulants who underwent photoselective vaporisation prostatectomy with a GreenLight High Performance System in the North District Hospital were studied. Data collected prospectively were analysed to determine perioperative and postoperative outcomes, including uroflowmetry parameters, serum prostate-specific antigen level, prostate volume, and complications at 1, 3, 6, and 12 months post-surgery. RESULTS: The patients' mean age was 76 (standard deviation, 7; range 62-94) years. The mean follow-up period was 13 (standard deviation, 9) months. Thirty-six (75%) patients had urinary retention prior to surgery. Bleeding tendencies were due to receipt of aspirin (n=36), two antiplatelet agents (n=6), warfarin (n=4) and clopidogrel (n=1), and to thrombocytopaenia (n=1). Preoperative transrectal ultrasonography showed a mean prostate size of 58 (standard deviation, 30; range, 18-154) mL. Of the patients, 81% were discharged without a catheter and their mean hospital stay was 3 days. Five patients were readmitted for secondary haemorrhage, two had a drop of more than 10 g/L in their haemoglobin level, but only one received a blood transfusion. Mean uroflowmetry parameters, namely, peak flow rate and residual volume, were 8.7 mL/s and 199 mL preoperatively and 14.7 mL/s and 50 mL 1 year after the operation. CONCLUSION: With an ageing population in which patients with various co-morbidities receive anticoagulant/antiplatelet therapy, photoselective vaporisation prostatectomy using a GreenLight High Performance System is a safe treatment option.
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Anticoagulantes/uso terapéutico , Terapia por Láser/métodos , Prostatectomía/métodos , Hiperplasia Prostática/cirugía , Administración Oral , Anciano , Anciano de 80 o más Años , Anticoagulantes/administración & dosificación , Anticoagulantes/efectos adversos , Estudios de Seguimiento , Hemorragia/etiología , Hemorragia/prevención & control , Humanos , Terapia por Láser/efectos adversos , Tiempo de Internación , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Antígeno Prostático Específico/sangre , Prostatectomía/efectos adversos , Hiperplasia Prostática/diagnóstico por imagen , Hiperplasia Prostática/patología , Factores de Tiempo , Resultado del Tratamiento , UltrasonografíaRESUMEN
The strain-rate response of flow stress in a plastically deforming crystal is formulated through a stress-sensitive dislocation mobility model that can be evaluated by atomistic simulation. For the flow stress of a model crystal of bcc Fe containing a 1/2[111] screw dislocation, this approach describes naturally a non-Arrhenius upturn at high strain rate, an experimentally established transitional behavior for which the underlying mechanism has not been clarified. Implications of our findings regarding the previous explanations of strain-rate effects on flow stress are discussed.
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BACKGROUND: A prior study showed significant antibiotic resistance to quinolone in our population. In this study we aimed to evaluate and compare the efficacy of a single versus a combined prophylactic antibiotic regimen before transrectal ultrasound-guided prostate biopsy (TRUGPB). METHODS: A prospective randomized study was conducted at a university hospital. Patients undergoing TRUGPB were randomized into an amoxicillin-clavulanate alone (1 mg; one dose before and two doses after biopsy) or an amoxicillin-clavulanate + ciprofloxacin group (250 mg; one dose before and two doses after biopsy). Patients were surveyed for infection symptoms by phone on days 3 and 30 after TRUGPB. We defined an infective complication as the occurrence of symptoms including fever, chills or rigor within 30 days after prostate biopsy, requiring medical treatment or hospitalization, aided by a territory-wide electronic medical record system. RESULTS: Between November 2007 and July 2009, 367 patients were randomized to either amoxicillin-clavulanate alone or amoxicillin-clavulanate + ciprofloxacin group. The infection rates after TRUGPB were 3.91% in the former group (7 out of 179 patients) versus 0.53% (1 out of 188 patients) in the latter. Sixty-three percent (5/8) of patients with infective complications needed hospitalization. There was no intensive care unit admission or mortality during the study period. CONCLUSIONS: Combining prophylactic antibiotics with amoxicillin-clavulanate + ciprofloxacin significantly reduced the incidence of infective complications after TRUGPB. We recommended a combination regimen, especially in centre with high incidence of post-TRUGPB infection.
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Antibacterianos/uso terapéutico , Profilaxis Antibiótica/métodos , Biopsia con Aguja/efectos adversos , Próstata/diagnóstico por imagen , Próstata/patología , Recto , Amoxicilina/uso terapéutico , Biopsia con Aguja/métodos , Ciprofloxacina/uso terapéutico , Ácido Clavulánico/uso terapéutico , Humanos , Masculino , Próstata/cirugía , UltrasonografíaRESUMEN
UNLABELLED: We quantified the urine sediment and supernatant levels of microRNA (miRNA) targets related to epithelial-mesenchymal transition in 51 patients with bladder cancer and in 24 controls. We found that patients with bladder cancer had depressed levels of the miR-200 family, miR-192, and miR-155 in urinary sediment. The urinary level of these miRNAs may be developed as noninvasive markers for bladder cancer. BACKGROUND: MicroRNAs (miRNA) have been implicated to play an important role in the pathogenesis of a variety of cancers. We studied the levels of miRNAs related to epithelial-mesenchymal transition (EMT) in the urine of patients with bladder cancer. METHOD: The expression of the miR-200 family, miR-205, miR-192, miR-155, and miR-146a in the urine sediment and supernatant of 51 patients with bladder cancer and in 24 controls was determined by real-time quantitative polymerase chain reaction. RESULTS: Compared with controls, the patients with bladder cancer had a lower expression of the miR-200 family, miR-192, and miR-155 in the urinary sediment; lower expression of miR-192; and higher expression of miR-155 in the urinary supernatant. The expression of the miR-200 family, miR-205, and miR-192 in the urine sediment significantly correlated with urinary expression of EMT markers, including zinc finger E-box-binding homeobox 1, vimentin, transforming growth factor ß1, and Ras homolog gene family, member A. Furthermore, the levels of miR-200c and miR-141 in the urine sediment became normalized after surgery. CONCLUSION: We found that the urinary miR-200 family, miR-155, miR-192, and miR-205 levels are depressed in patients with bladder cancer. The level of these miRNA targets in urine has the potential to be developed as noninvasive markers for bladder cancer.
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Biomarcadores de Tumor/orina , Carcinoma de Células Transicionales/orina , MicroARNs/orina , Neoplasias de la Vejiga Urinaria/orina , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/genética , Carcinoma de Células Transicionales/cirugía , Estudios de Casos y Controles , Transición Epitelial-Mesenquimal , Femenino , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/orina , Humanos , Masculino , MicroARNs/genética , Persona de Mediana Edad , ARN Mensajero/genética , ARN Mensajero/orina , Reacción en Cadena en Tiempo Real de la Polimerasa , Factores de Transcripción/genética , Factores de Transcripción/orina , Transcripción Genética , Factor de Crecimiento Transformador beta1/genética , Factor de Crecimiento Transformador beta1/orina , Neoplasias de la Vejiga Urinaria/cirugía , Vimentina/genética , Vimentina/orina , Homeobox 1 de Unión a la E-Box con Dedos de Zinc , Proteína de Unión al GTP rhoA/genética , Proteína de Unión al GTP rhoA/orinaRESUMEN
UNLABELLED: Study Type - Diagnostic (exploratory cohort) Level of Evidence 3b What's known on the subject? and What does the study add? Electronic uroflowmetry reasonably predicts the likelihood of bladder outlet obstruction (BOO) and risk of AUR. This low-cost device, Uflowmeter(™) , allows men to perform uroflowmetry at home with ease and the results are compatible with that of electronic uroflowmentry. It can also estimates risk of AUR and the need for TURP to relieve LUTS. OBJECTIVE: To show the clinical value of a simple flowmeter, which has been devised to measure uroflow on an ordinal scale (<10, 10-15, 15-19 and >19 mL/s) at home, for the management of male lower urinary tract symptoms (LUTS). PATIENTS AND METHODS: A total of 186 men with LUTS were enrolled in the study. The mean (range) follow-up was 220 (68-431) days. The men's mean (range) age was 65.5 (46-83) years, mean (range) maximum urinary flow rate (Qmax) 12.8 (4.3-39.5) mL/s, mean (range) voided volume 294.8 (151-686) mL; mean (range) postvoid residual urine volume (PVR) 50 (0-303) mL and mean (range) International Prostate Symptom Score (IPSS) 13.5 (1-31). The men underwent electronic uroflowmetry ('clinic uroflowmetry') and completed an IPSS questionnaire in the clinic. They then conducted 10 measurements with the device at home ('home uroflowetry'). The uroflowmetry and IPSS questionnaire were repeated 2 weeks later. Quadratically weighted Kappa analysis (κ) of the home uroflowmetry vs. clinic uroflowmetry, and of the sensitivity and specificity of the home uroflowmetry values to correspond to the mean Qmax of clinic uroflowmetry (<10, 10-15, 15-19 and >19 mL/s) was performed. Similar analyses were performed for the IPSS. Kaplan-Meier analysis was performed to evaluate whether home uroflowmetry was able to prognosticate acute urinary retention (AUR) or the need for transurethral resection of the prostate (TURP). RESULTS: The home uroflowmetry values (κ= 0.84, 95% confidence interval [CI]: 0.78-0.90) were superior to the IPSS (κ= 0.083; 95% CI: 0-0.173) in correlating with the mean Qmax of clinic uroflowmetry. Home uroflowmetry was most sensitive in identifying a mean Qmax of >19 mL/s (sensitivity: 0.99; 95% CI:0.97-1.00) and most specific in identifying a mean Qmax of <10 mL/s (specificity: 0.90; 95% CI:0.83-0.94). The home uroflowmetry works best in ruling out a mean Qmax of <19 mL/s (diagnostic odds ratio [DOR]= 349.3; 95% CI:40.24-3037.7), followed by a mean Qmax of <15 mL/s (DOR = 91.02; 95% CI:31.23-265.23) and a mean Qmax of <10 mL/s (DOR = 32.04; 95% CI:14.0-73.19). Men with a home uroflowmetry value ≤10 mL/s were more likely (n= 6; 8.8%) than those with a home uroflowmetry value >10 mL/s (n= 2; 1.7%) to develop AUR or require TURP (log-rank test: P= 0.017; hazard ratio:5.61(95% CI:1.10-28.64)). The IPSS failed to display the same discriminative capability. CONCLUSION: Home uroflowmetry using this simple device is a satisfactory estimation of clinic uroflowmetry using an electronic flowmeter and can predict the significant progression of male LUTS.
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Flujómetros , Síntomas del Sistema Urinario Inferior/diagnóstico , Hiperplasia Prostática/complicaciones , Reología/instrumentación , Autocuidado/instrumentación , Obstrucción del Cuello de la Vejiga Urinaria/diagnóstico , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Diseño de Equipo , Humanos , Síntomas del Sistema Urinario Inferior/etiología , Síntomas del Sistema Urinario Inferior/terapia , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Hiperplasia Prostática/fisiopatología , Hiperplasia Prostática/terapia , Obstrucción del Cuello de la Vejiga Urinaria/etiología , Obstrucción del Cuello de la Vejiga Urinaria/terapia , Micción/fisiología , Urodinámica/fisiologíaRESUMEN
We report an unusual complication of intravesical Bacillus Calmette-Guérin therapy for superficial bladder cancer, namely, retention of urine secondary to prostatic Bacillus Calmette-Guérin infection and abscess. A summary of the literature together with a review of its management is discussed.
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Adyuvantes Inmunológicos/efectos adversos , Vacuna BCG/efectos adversos , Neoplasias de la Vejiga Urinaria/tratamiento farmacológico , Retención Urinaria/etiología , Absceso/complicaciones , Absceso/microbiología , Adyuvantes Inmunológicos/uso terapéutico , Anciano , Vacuna BCG/uso terapéutico , Humanos , Masculino , Mycobacterium , Infecciones por Mycobacterium/complicaciones , Infecciones por Mycobacterium/tratamiento farmacológico , Enfermedades de la Próstata/complicaciones , Enfermedades de la Próstata/microbiología , Retención Urinaria/terapiaAsunto(s)
Neoplasias de Células Epitelioides Perivasculares/patología , Neoplasias de la Vejiga Urinaria/patología , Adulto , Biomarcadores de Tumor/análisis , Humanos , Inmunohistoquímica , Masculino , Neoplasias de Células Epitelioides Perivasculares/metabolismo , Neoplasias de la Vejiga Urinaria/metabolismoRESUMEN
BACKGROUND AND PURPOSE: In comparison with monopolar transurethral resection of the prostate (TURP), bipolar TURP has been shown to have similar efficacy and complication profiles. Whether the hybrid technique of bipolar resection and vaporization of the prostate further improves catheterization time, dysuria, and complication profiles has not been defined, however. The objective of this study was to compare the efficacy and safety profile of bipolar hybrid prostate surgery using both resection and vaporization modes, with bipolar resection undertaken using the transurethral resection in saline bipolar system. PATIENTS AND METHODS: This was a randomized controlled trial that compared bipolar hybrid surgery and bipolar resection of the prostate among men aged ≥ 50 years with benign prostatic hyperplasia (BPH) whose course of medical therapy had failed or who had recurrent urinary retention (CUHK_CCT00623). Patients were randomly assigned to receive either bipolar hybrid surgery or bipolar resection of the prostate. Both patients and assessors were blinded to the type of surgery performed. The primary study end point was catheter time. The secondary end points included postoperative hospital stay and dysuria score. We report the interim results for 86 patients. RESULTS: Forty-six patients were in the hybrid group and 40 were in the resection group. There were no differences between the two groups in prostate volumes (61.5 cc, standard deviation [SD]=34.5 vs 61.0 cc, SD=23.8), preoperative prostate-specific antigen levels (8.7 ng/mL, SD=8.5 vs 9.5 ng/mL, SD=8.4), or preoperative retention status (56.5% vs 70%). The mean operative time was 46.2 minutes for the hybrid group (SD=20.2) and 39.2 minutes for the resection group (SD=17.5). The hybrid group had a significantly shorter postoperative catheter time (34.5 h, SD=15.8 vs 44.7 h, SD=24.5, P=0.027). There was a significant difference between the two groups in the postoperative pain score on day 1 postsurgery (3.5 in the hybrid group vs 1.0 in the resection group, P=0.028). There was no difference between the groups in terms of changes in serum hemoglobin and serum sodium levels or the reintervention rate. All patients voided well after operation, with maximal flow improvements of 9.9 mL/s (SD 8.1) and 8.2 mL/s (SD 10.0) for the hybrid and resection groups, respectively, 1 month postsurgery. CONCLUSION: Transurethral bipolar resection and vaporization of the prostate reduces catheterization time and facilitates postoperative care.