Gernot Bonkat

Comparison of potassium-titanyl-phosphate laser vaporization of the prostate and transurethral resection of the prostate: update of a prospective non-randomized two-centre study.

To evaluate the intermediate‐term clinical efficacy and the rate of complications in 80 W photoselective vaporization of the prostate (PVP) with the potassium‐titanyl‐phosphate laser (GreenlightTM, (AMS, Minnetonka, MN, USA) compared with transurethral resection of the prostate (TURP) in a prospective non‐randomised two‐centre study.

Microcalorimetric assays for measuring cell growth and metabolic activity: Methodology and applications

Isothermal microcalorimetry measures the heat released or consumed by physical or chemical processes. Metabolic activity releases heat that can be measured. However the calorimetric signal can be difficult for new users to interpret. This paper compares microcalorimetry to other techniques and reviews its application to different fields where microbiological activity is important. We also describe different ways to analyze the data and translate it into meaningful (micro)biological equivalents. This paper aims at providing non-specialist reader the tools to understand how isothermal microcalorimetry can be used for microbiological applications.

Rapid detection of urinary tract pathogens using microcalorimetry: principle, technique and first results

Study Type – Diagnostic (exploratory cohort)

The effect of increased maximum power output on perioperative and early postoperative outcome in photoselective vaporization of the prostate

Preclinical studies suggest an increased vaporization rate and speed of the 532 nm 180‐W XPS GreenLight laser (180‐W) compared with the 120‐W HPS GreenLight laser (120‐W) and the 80‐W PV GreenLight laser (80‐W). To test the clinical relevance of this observation we analyzed intraoperative data and early postoperative results after photoselective vaporization of the prostate (PVP) with the 180‐W, 120‐W, and 80‐W laser.

Seven Hours to Adequate Antimicrobial Therapy in Urosepsis Using Isothermal Microcalorimetry

ABSTRACT Urosepsis can progress toward severe sepsis, septic shock, and, ultimately, death. Rapid antimicrobial susceptibility testing is crucial to decrease mortality and morbidity. This report shows that isothermal microcalorimetry can provide an antibiogram within 7 h with a sensitivity of 95% and specificity of 91% using Vitek-2 system as a reference.

Isothermal microcalorimetry accurately detects bacteria, tumorous microtissues, and parasitic worms in a label-free well-plate assay

Isothermal microcalorimetry is a label-free assay that allows monitoring of enzymatic and metabolic activities. The technique has strengths, but most instruments have a low throughput, which has limited their use for bioassays. Here, an isothermal microcalorimeter, equipped with a vessel holder similar to a 48-well plate, was used. The increased throughput of this microcalorimeter makes it valuable for biomedical and pharmaceutical applications. Our results show that the sensitivity of the instrument allows the detection of 3 × 104 bacteria per vial. Growth of P. mirabilis in Luria Broth medium was detected between 2 and 9 h with decreasing inoculum. The culture released 2.1J with a maximum thermal power of 76 μW. The growth rate calculated using calorimetric and spectrophotometric data were 0.60 and 0.57 h–1, respectively. Additional insight on protease activities of P. mirabilis matching the last peak in heat production could be gathered as well. Growth of tumor microtissues releasing a maximum thermal power of 2.1 μW was also monitored and corresponds to a diameter increase of the microtissues from ca. 100 to 428 μm. This opens new research avenues in cancer research, diagnostics, and development of new antitumor drugs. For parasitic worms, the technique allows assessment of parasite survival using motor and metabolic activities even with a single worm.

Growth of Mycobacteria in Urine Determined by Isothermal Microcalorimetry: Implications for Urogenital Tuberculosis and Other Mycobacterial Infections

OBJECTIVE To overcome the limitations of current urine-based diagnostic assays of urogenital tuberculosis, we used isothermal microcalorimetry to detect the metabolic activity of Mycobacterium tuberculosis and other commonly neglected pathogenic mycobacteria in urine and accurately determine their growth parameters. METHODS A microcalorimeter equipped with 48 channels was used. Detection was accomplished, and growth was monitored for 4 different Mycobacterium species in sterilized and modified urine at 37 °C by measuring metabolic heat flow (μW = μJ/s) as a function of time. These strains were M. smegmatis, M. phlei, M. kansasii, and M. tuberculosis. The data were integrated to perform curve fitting and extract the growth parameter from the raw data. RESULTS In sterilized urine, M. smegmatis showed the fastest growth rate (0.089 ± 0.017 [h(-1)]), followed by M. phlei (0.072 ± 0.016 [h(-1)]) and M. kansasii (0.007 ± 0.001 [h(-1)]). No growth of M. tuberculosis was detected in sterilized urine. However, in serum-supplemented urine, growth of M. tuberculosis was observed within 3 weeks at a growth rate of 0.008 ± 0.001 [h(-1)]. Biofilm formation was enhanced in the serum supplemented urine. CONCLUSION Isothermal microcalorimetry allows rapid and accurate detection of mycobacterial growth in urine. Given the absence of data on the mycobacterial growth in urine, isothermal microcalorimetry could be used to unravel key aspects of Mycobacterium physiology in the urinary tract and potentially contribute to improvement in the diagnosis and treatment of urogenital tuberculosis.

Novel microcalorimetric assay for antibacterial activity of implant coatings: The cases of silver-doped hydroxyapatite and calcium hydroxide.

Biomaterials with antimicrobial properties are now commonly used in different clinical specialties including orthopedics, endodontic, and traumatology. As a result, assessing the antimicrobial effect of coatings applied on implants is of critical importance. In this study, we demonstrate that isothermal microcalorimetry (IMC) can be used for monitoring bacterial growth and biofilm formation at the surface of such coatings and for determining their antimicrobial effects. The antibacterial effects of silver doped hydroxyapatite (HA) and calcium hydroxide coatings on Staphylococcus epidermidis were determined with a minimal workload. Using the Gompertz growth model we determined biofilm growth rates close to those values reported in the literature. Furthermore, we were able to estimate the reduction in the bacterial inocula originally applied at the surface of the coatings. Therefore, in addition to monitoring the antimicrobial effect of silver doped HA and calcium hydroxide coatings, we also demonstrate that IMC might be a valuable tool for assessing such antimicrobial properties of implant coatings at a minimal workload.

Urothelial Cancer in Renal Transplant Recipients: Incidence, Risk Factors, and Oncological Outcome

OBJECTIVE To evaluate the incidence and risk factors for urothelial cancer (UC) as well as the oncological outcome and allograft function in renal transplant recipients. SUBJECTS/PATIENTS We conducted a retrospective analysis of 1855 consecutive patients undergoing renal transplantation (TX) between February 1982 and May 2014 at a single center. UC incidence, overall and cancer-specific survival, recurrence and progression rates, risk factors for UC, and renal function were determined. Fishers exact test and log-rank Mantel-Cox test were used as appropriate. RESULTS In renal transplant recipients, incidence of de novo UC was 1.35% (25/1855). Deceased donor transplantation (P = .002), increased age at transplantation (P = .011), and analgesic abuse (P = .005) were significant risk factors for the development of UC post-TX. Progression rate and recurrence rate were doubled for post-TX-UC but stable for patients with pre-TX-UC compared with the general population. Analgesic abuse was associated with worse cancer specific and overall survival in post-TX patients. The overall survival status was significantly lower for post-TX patients at a median of 34 months vs 222 months in control patients. Adjuvant treatment was scarcely used. UC had no significant influence on graft function. CONCLUSION A higher incidence of UC was identified in renal transplant recipients compared with that for the general population. These observations justify screening for UC in renal transplant patients, especially considering that in a large proportion, a tentative diagnosis was possible with noninvasive urine analysis. Prudent adjuvant treatment for UC should be used. Limitations of this study were the retrospective design and the single-center experience.

Benefits and Harms of Treatment of Asymptomatic Bacteriuria: A Systematic Review and Meta-analysis by the European Association of Urology Urological Infection Guidelines Panel

People with asymptomatic bacteriuria (ABU) are often unnecessarily treated with antibiotics risking adverse effects and antimicrobial resistance. We performed a systematic review to determine any benefits and harms of treating ABU in particular patient groups. Relevant databases were searched and eligible trials were assessed for risk-of-bias and Grading of Recommendations, Assessment, Development and Education quality. Where possible, a meta-analysis of extracted data was performed or a narrative synthesis of the evidence was presented. After screening 3626 articles, 50 studies involving 7088 patients were included. Overall, quality of evidence ranged from very low to low. There was no evidence of benefit for patients with no risk factors, patients with diabetes mellitus, postmenopausal women, elderly institutionalised patients, patients with renal transplants, or patients prior to joint replacement, and treatment was harmful for patients with recurrent urinary tract infection (UTI). Treatment of ABU resulted in a lower risk of postoperative UTI after transurethral resection surgery. In pregnant women, we found evidence that treatment of ABU decreased risk of symptomatic UTI, low birthweight, and preterm delivery. ABU should be treated prior to transurethral resection surgery. In addition, current evidence also suggests that ABU treatment is required in pregnant women, although the results of a recent trial have challenged this view. PATIENT SUMMARY We reviewed available scientific studies to see if people with bacteria in their urine but without symptoms of urinary tract infection should be treated with antibiotics to eliminate bacteria. For most people, treatment was not beneficial and may be harmful. Antibiotic treatment did appear to benefit women in pregnancy and those about to undergo urological surgery.