Removal Of Encrustation Research Articles

Проблема клинической диагностики и лечения инкрустирующего цистита

Encrusted cystitis (IC) is a rare chronic inflammatory disorder of the bladder characterized by mucosal inflammation with encrustations. This pathological process is directly related to the activity of urea-splitting bacteria in the urine. Bladder encrustations are deposits of ammonium and magnesium phosphate, as well as struvite, on the surface of the urothelium. However, the pathogenesis of this disease has not been thoroughly studied. Treatment of encrusted cystitis is aimed to complete eradication of the uropathogen, surgical removal of encrustations, and lowering urine pH. Early diagnosis is a key prerequisite for effective treatment.

Balgray Reservoir: outlet pipework condition assessment and rehabilitation

This paper describes the investigations undertaken at Balgray Reservoir after concerns were raised regarding the condition of the heavily encrusted original cast-iron pipework, which dates from 1853. Testing of the thickness and hardness of a section of the pipe as well as testing of the encrustation was used to determine the materials present. The results of these investigations were used to determine the implications for the condition of the pipe and the resulting risks posed to the dam. This informed the potential options for the required remediation works. Details are provided for the case study, the investigations and findings, and potential options for encrustation removal.

Encrusted Uropathy: A Comprehensive Overview-To the Bottom of the Crust.

Encrusted uropathy is a rare subacute to chronic inflammatory disorder caused by infection with urease-producing bacteria, mainly Corynebacterium urealyticum. The disorder is characterized by urothelial deposition of struvite and carbonated apatite, resulting in encrustations and ulceronecrotic inflammation of the urothelium and surrounding tissues. Most commonly, encrusted uropathy is encountered in patients with predisposing conditions. The disease remains underdiagnosed. High urinary pH and negative conventional urine cultures should raise suspicion of the diagnosis. Prognosis is dependent on timely diagnosis and treatment installment, which consists of urological removal of encrustations in combination with urinary acidification and long-term antibiotic therapy.

Preliminary in Vitro Studies on Corynebacterium urealyticum Pathogenetic Mechanisms, a Possible Candidate for Chronic Idiopathic Prostatitis?

Corynebacterium urealyticum is a well-known opportunistic uropathogen that can occur with cystitis, pyelonephritis, and urinary sepsis. Although a wide variety of coryneform bacteria have been found from the male genital tract of prostatitis patients, only one clinical case of prostatitis caused by C. urealyticum has been reported. The aim of this study was to evaluate the in vitro tropism of C. urealyticum towards LNCaP (lymph node carcinoma of the prostate) human cells line and the influence of acetohydroxamic acid as an irreversible urease inhibitor on different aspects of its pathogenicity by means of several in vitro tests, such as the determination and analysis of growth curves, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, the production of biofilms, and adhesion to LNCaP and HeLa cell lines. Results have brought new pieces of evidence on the in vitro tropism of C. urealyticum for the human prostate cell line LNCaP and the therapeutic use of the irreversible urease inhibitors such as acetohydroxamic acid (AHA), not only as enzyme blockers to facilitate the removal of encrustations but also as modulators of some pathogenic mechanisms. These interesting preliminary data allow us to assert that there is a real possibility that C. urealyticum is a new candidate for chronic idiopathic prostatitis.

Development of a hybrid photoacoustic and optical monitoring system for the study of laser ablation processes upon the removal of encrustation from stonework

In the context of this work, a prototype hybrid photoacoustic (PA) and optical system for the on-line monitoring of laser cleaning procedures is presented. The developed apparatus has enabled the detection of MHz frequency range acoustic waves generated during the laser ablation process. The intrinsically generated PA signals combined with high resolution optical images provide the opportunity to follow the cleaning process accurately and in real time. Technical mock-ups have been used to demonstrate the potential of this novel technique with emphasis given to applications that refer to the restoration of Cultural Heritage (CH) surfaces. Towards this purpose, the real time monitoring of the laser assisted removal of unwanted encrustation from stonework has been achieved using IR and UV wavelengths. This novel approach has allowed for the precise determination of the critical number of laser pulses required for the elimination of the encrustation layer, while highlighting the dominant ablation mechanisms according to the irradiation wavelength. The promising results obtained using the prototype hybrid PA and optical system can open up new perspectives in the monitoring of laser cleaning interventions, promoting an improved restoration outcome.

The laser as a tool for the cleaning of Cultural Heritage

Laser ablation is one of the most important irradiation effect which can be induced on optically absorbing materials. Laser cleaning is a particular case of laser ablation where a specific substrate is uncovered through the removal of undesired layers. The idea of using laser ablation for the selective removal of encrustations from the surface of artifacts dates back to the 70s. However, only in the last years, thanks to studies on the ablative process and on the development of dedicated laser systems, laser cleaning has become a daily routine in the world of conservation. The development of brand new devices optimized for the cleaning of artworks is here reported: the innovative machines exploit the versatility provided by the presence of different pulse durations, which turned out to be a key parameter in the laser-target interaction. In addition to the well-known laser cleaning of stones, novel applications are discussed such as the cleaning of metals, wall paintings, and the novel use of the Er:YAG laser for the removal of aged varnishes from easel paintings. The growing flexibility and versatility of the new laser systems dedicated to the cleaning of artworks enlarge the panorama of successful application of this cleaning method.

Prospective Analysis of a Complete Retrograde Ureteroscopic Technique with Holmium Laser Stent Cutting for Management of Encrusted Ureteral Stents.

Purpose: To propose and evaluate a new endoscopic technique using only a retrograde ureteroscopic approach for the removal of heavily encrusted ureteral stents. Methods: Data from 51 consecutive patients with encrusted and retained ureteral stents were prospectively collected. Description of the successive steps of surgery is detailed. The holmium yttrium aluminum garnet (Ho:YAG) laser properties offer the opportunity for fragmentation of stent-attached encrustation and the ability to cut the stent itself. Reducing the length of the stent is critical to creating space in the ureter and to allow free access for ureteroscopes or ureteral access sheath placement. The primary outcome of this study was the feasibility and the safety of this retrograde intrarenal approach. Some factors of encrustation and outcomes are also discussed in comparison with lithotripsy, percutaneous, laparoscopic, open surgery, or a combination of these techniques. Results: The removal of the encrusted stent was possible with only this retrograde technique in 98% of patients. The transection of the encrusted stent with the Ho:YAG laser was useful in 71% of the patients. Mean operative time was 110 minutes and mean hospital stay was 2.33 days. Postoperative complications were mainly nonobstructive pyelonephritis (10%). The most significant predictor of this life-threatening complication was the presence of struvite stones with the encrusted stent (p = 0.018). Contrariwise, operative time, body mass index, gender, and encrustation rate were not associated with postoperative pyelonephritis. Both cystine stone disease and pregnancy led to faster stent encrustation. Conclusions: Retrograde ureteroscopic surgery is efficient and safe for removing retained stents and associated stone burdens. The Ho:YAG laser is essential to perform the encrustation removal and sectioning of the stent.

Encrusted Cystitis

We report a case of a patient who developed encrusted cystitis after transurethral resection of the prostate. This rare urological condition is characterized by intramucosal calcifications and is commonly preceded by urological instrumentation. Urea-splitting bacteria, most commonly Corynebacterium urealyticum, are the causative pathogen. Treatment is a combination of antibiotics, urine acidification, and endoscopic removal of encrustations.

Mechanism and Prediction of Laser Wet Cleaning of Marble Encrustation

During the removal of encrustation from marble with 355nm laser pulses, the effects of the thin liquid layer covering the encrustation are experimentally and numerically investigated. The working mechanism of the liquid layer is analyzed. A two-dimensional axial symmetric model is proposed to simulate the changes in the temperature, liquid volumetric fraction, and vapor pressure in the irradiated encrustation. To model the conservation of mass, momentum, and energy, three coupled nonlinear partial differential equations are numerically solved. The measured porosity of the encrustation is incorporated into the model. Marble cleaning with three different liquids having different thermodynamic properties, distilled water, ethanol, and acetone, are compared in terms of the cleaning efficiency at different fluence levels. With the liquid layer, the surface color of cleaned marble is also studied. In addition, surface-enhanced raman spectroscopy and a chromameter are used to identify the chemical constituents and measure the color of the cleaned marble, respectively.

Quantitative laser induced breakdown spectroscopy analysis of ancient marbles and corrections for the variability of plasma parameters and of ablation rate

White marble samples from ancient quarries have been analyzed by Laser Induced Breakdown Spectroscopy (LIBS) both on the bulk material and surface encrustations. With the aim to achieve quantitative results by LIBS, until now not reported on marble materials, calibration standards with CaCO3 matrices doped with certified soils were realized. Very different emission intensities and plasma parameters were observed on the standards and natural marbles. In order to compare so different spectra, a method for data analysis was developed, which takes into account variability of the ablation rate, plasma temperature and electron density. It was experimentally demonstrated that ablated volume is well correlated to the emission intensity of plasma continuum for a wide range of laser energies. LIBS signal normalization on the adjacent continuum level, together with introduction of correction factors dependent on plasma parameters, allowed the measuring of concentrations both for major and trace elements in marbles. The analytical procedure was validated by comparative SEM-EDX and ICP-OES measurements. Quantitative LIBS analyses were also performed during encrustation removal and could be applied to control laser-cleaning processes. The quantification of metal contents in the encrustations supported the occurrence of sulfates in the outer layers exposed to environmental agents via a catalytic process.

Excimer laser cleaning of encrustation on Pentelic marble: procedure and evaluation of the effects

This work focuses on the use and control of excimer lasers (KrF, λ=248 nm and XeCl, λ=308 nm) for the removal of encrustation (black crusts, soil-dust and biological deposits) from Pentelic marble. A number of surface analytical techniques, such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) interfaced with microprobe analysis (energy dispersive X-ray analysis: EDX), X-ray diffraction (XRD), laser-induced breakdown spectroscopy (LIBS) and optical microscopy (OM) were used to detect chemical composition and crust morphology, as well as to monitor the effects induced by the laser treatment. SEM and OM providing structural information about the layers of encrustation, LIBS and SEM–EDX providing information on the elemental composition of the ablated material, XRD and FTIR detecting the changes of minerals appear to be particularly effective in assessing the quality of cleaning process. FTIR and XRD showed removal of pollutants from encrustation and partial transformation of calcium sulfate dihydrate (gypsum) to hemihydrate and anhydrite, which have lower specific surface than gypsum. Irradiation conditions creating minimal damaging effects were defined before treatment through surface analysis, ablation rate studies and optimization of laser parameters. On the basis of structural and analytical examinations, both lasers are shown to be appropriate for achieving sufficient removal of unwanted selected layers without modifying the surface morphology and surpassing by far the effectiveness afforded by traditional cleaning techniques.

Lasers for the Cleaning of Statuary: Initial Results and Potentialities

Cleaning is one of the most difficult operations encountered in the restoration of statuary. The fact that known cleaning methods are not entirely satisfactory has stimulated continuing research into new methods and processes. A novel method is proposed for cleaning superficial black scabs or patinas from works of art in marble or other stone by means of laser radiation. Surface cleaning results with a ruby laser are reported and compared with conventional techniques. Preliminary analyses of the laser process are quite favorable and indicate improved selectivity and graduation, self-limiting encrustation removal, and remarkably rapid surface coverage. Finally, the results of cleaning tests with various laser types are presented and discussed, and possible future developments and pratical applications of this new method of cleaning statuary are presented.