2D Image Quantification of Microbial Iron Chelators (Siderophores) Using Diffusive Equilibrium in Thin Films Method.

Siderophores are natural metal chelating agents that strongly control the biogeochemical metal cycles such as Fe in the environment. This article describes a new methodology to detect and quantify at the micromolar concentration the spatial distribution at millimeter scale of siderophores within the root's system. The "universal" CAS assay originally designed for bacterial siderophores detection and later designed for fungus was adapted here for diffusive equilibrium in thin film gel techniques (DET). The method was calibrated against the marketed desferrioxamine mesylate (DFOM) siderophore and applied with experiments performed with sunflower ( Helianthus annuus) and wheat ( Triticum aestivum) cultivated on free iron agar medium plates. We present here the first results with 2D images of the siderophores distribution in the vicinity of the root system of plants. With this technique we detected (i) the production of siderophores on bacteria inoculated ( Pseudomonas fluorescens) environments and (ii) hotspots of natural iron binding ligands production up to 50 µM in the wheat rhizosphere. The lower detection limit in our experiment was 2.5 µmol/L. This new technique offers a unique opportunity to investigate the siderophore production in two dimensions in a wide range of applications from laboratory experiments to natural systems very likely using an in situ and nondestructive tool.

Does surgical delay for radical prostatectomy affect patient pathological outcome? A retrospective analysis from a Canadian cohort.

INTRODUCTION: We sought to assess the impact of surgical wait time (SWT) to robot-assisted radical prostatectomy (RARP) on final pathological outcome. METHODS: A retrospective review of RARP patient records operated between 2006 and 2015 was conducted. SWT was defined as period from prostate biopsy to surgery. Primary outcome was the impact on postoperative Cancer of the Prostate Risk Assessment (CAPRA-S) score. Patients were stratified according to D'Amico risk categories. Univariate analysis (UVA) and multivariable (MVA) analysis with a generalized linear model was used to evaluate the effect of SWT and other predictive factors on pathological outcome in individual risk group and on the overall sample. RESULTS: A total of 835 patients were eligible for analysis. Mean SWT was significantly different between the three D'Amico groups, with mean SWT of 180.22 days (95% confidence interval [CI] 169.03; 191.41), 159.14 days (95% CI 152.38; 165.90), and 138.96 days (95% CI 124.60; 153.33) for low-, intermediate-, and high-risk groups, respectively (p<0.001). After stratification by D'Amico risk group, no significant association was observed between SWT and CAPRA-S score in the three risk categories on UVA and MVA. Predictors of higher CAPRA-S score in the multivariable model in the overall cohort were: older age (p=0.014), biopsy Gleason score (p<0.001), percentage of positive cores (p<0.001), and clinical stage (p<0.001). CONCLUSIONS: In the present study evaluating SWT for RARP in a Canadian socialized system, increased delay for surgery does not appear to impact the pathological outcome. Further studies are required to evaluate the impact of wait time on biochemical recurrence-free survival, cancer-specific survival, and overall survival.

Erectile function recovery after robotic-assisted radical prostatectomy (RARP): long term exhaustive analysis across all preoperative potency categories.

INTRODUCTION: To evaluate erectile function recovery following robotic-assisted radical prostatectomy (RARP) according to preoperative sexual health inventory for men (SHIM) score stratification. MATERIALS AND METHODS: We prospectively collected data on 250 consecutive patients who underwent RARP by a single surgeon between October 2006 and October 2012. Thirty-six patients were excluded because of lack of preoperative SHIM score. All patients had a minimum follow up of 2 years. Patients were divided into four groups according to their preoperative SHIM score: group 1 with normal potency (SHIM 22-25), group 2 with mild ED (SHIM 17-21), group 3 with mild-moderate ED (SHIM 12-16) and group 4 with moderate-severe ED (SHIM 1-11). Patients were followed at 3, 6, 9, 12, 18, 24 months intervals and twice yearly thereafter. SHIM questionnaire and erection hardness scale (EHS) score were collected at each visit. Potency was defined as successful penetration during intercourse (EHS score 3-4) with or without phosphodiesterase type 5-inhibitor (PDE5-I). RESULTS: After exclusion, 214 patients were evaluated. The number of patients in group 1, 2, 3 and 4 were 95, 59, 26 and 34, respectively. At 3, 6, 9, 12, 18, 24 months, SHIM scores and potency rates were statistically different between groups 1 versus 2 versus 3 versus 4 (p < 0.01, at each time point). Patients in each group 1, 2 and 3 showed a statistically significant improvement in potency rates and SHIM scores at consecutive follow up visits up to 24 months (p < 0.01, for each potency group). Potency rates at 24 months for groups 1 to 4 were 83.3%, 54.5%, 50.0%, and 20.7%, respectively (p < 0.001). CONCLUSION: For proper patient counseling and better prediction of erectile function recovery after RARP, it is important to stratify patients according to preoperative SHIM scores. Setting realistic expectations may increase patient satisfaction.

Uroflow Stop Test and Potency Recovery: A Surrogate for Pelvic Floor Integrity Post Robotic-Assisted Radical Prostatectomy?

OBJECTIVE: To study the relation between uroflow Stop Test and early recovery of potency following robot-assisted radical prostatectomy (RARP). We recently showed that the ability to completely stop urine flow during voiding, measured objectively by uroflowmetry at the time of catheter removal (uroflow Stop Test) can predict early urinary continence recovery following RARP. MATERIALS AND METHODS: In this prospective observational cohort, data were collected on 108 patients operated by a single surgeon (AEH). Eighty patients had a positive uroflow Stop Test (group one) and 28 had a negative Stop Test (group two). Patients were followed for a minimum of 2 years. Covariates included age, body mass index, international prostate symptom score and sexual health inventory for men scores, prostate-specific antigen, tumor stage, prostate volume, nerve sparing status, and estimated blood loss. RESULTS: Preoperative characteristics were comparable between both groups except nerve sparing and prostate-specific antigen which were statistically higher in group one (P <.05). Early 3- and 6-months recovery of erectile function was significantly higher in group one. Potency rates in group one and two at 1, 3, 6, 9, 12, 18, and 24 months were 25% vs 14.3% (P = .241), 54.5% vs 18.5% (P = .001), 55.4% vs 18.5% (P = .001), 56.4% vs 36% (P = .084), 66.6% vs 50% (P = .141), 65.5% vs 56% (P = .404) and 73.2% vs 57.7% (P = .160) respectively. Uroflow Stop Test was independent predictor of early potency recovery on multivariate regression analysis at 6 months [odds ratio 6.042 (confidence interval 95% 1.496-24.413) P = .012]. CONCLUSION: Uroflow Stop Test is simple and can help predict early potency recovery following RARP.

Oncological and functional outcomes of 722 robot-assisted radical prostatectomy (RARP) cases: The largest Canadian 5-year experience.

INTRODUCTION: While RARP (robotic-assisted radical prostatectomy) has become the predominant surgical approach to treat localized prostate cancer, there is little Canadian data on its oncological and functional outcomes. We describe the largest RARP experience in Canada. METHODS: Data from 722 patients who underwent RARP performed by 7 surgeons (AEH performed 288, TH 69, JBL 23, SB 17, HW 15, QT 7, and KCZ 303 patients) were collected prospectively from October 2006 to December 2013. Preoperative characteristics, as well as postoperative surgical and pathological outcomes, were collected. Functional and oncological outcomes were also assessed up to 72 months postoperative. RESULTS: The median follow-up (Q1-Q3) was 18 months (9-36). The D'Amico risk stratification distribution was 31% low, 58% intermediate and 11% high-risk. The median operative time was 178 minutes (142-205), blood loss was 200 mL (150-300) and the postoperative hospital stay was 1 day (1-23). The transfusion rate was only 1.0%. There were 0.7% major (Clavien III-IV) and 10.1% minor (Clavien I-II) postoperative complications, with no mortality. Pathologically, 445 men (70%) were stage pT2, of which 81 (18%) had a positive surgical margin (PSM). In addition, 189 patients (30%) were stage pT3 and 87 (46%) with PSM. Urinary continence (0-pads/day) returned at 3, 6, and 12 months for 68%, 80%, and 90% of patients, respectively. Overall, the potency rates (successful penetration) for all men at 6, 12, and 24 months were 37%, 52%, and 59%, respectively. Biochemical recurrence was observed in 28 patients (4.9%), and 14 patients (2.4%) were referred for early salvage radiotherapy. In total, 49 patients (8.4%) underwent radio-therapy and/or hormonal therapy. CONCLUSIONS: This study shows similar results compared to other high-volume RARP programs. Being the largest RARP experience in Canada, we report that RARP is safe with acceptable oncologic outcomes in a Canadian setting.

The role of a well-trained team on the early learning curve of robot-assisted laparoscopic procedures: the example of radical prostatectomy.

BACKGROUND: The robot-assisted laparoscopic approach for radical prostatectomy (RARP) is being performed increasingly worldwide to treat localized prostate cancer (PCa). The aim of this study was to compare the learning curves of two surgeons with different surgical experiences. METHODS: A prospective collection of peri-operative data was made: age, body mass index, PSA, clinical stage, biopsy Gleason score, operative time (OT), blood loss (BL), pathological stages, final Gleason scores, and complications. Patients were included, in two groups. The first group comprised the first 100 patients undergoing RARP by an expert laparoscopic surgeon. The second group of 100 patients was operated on by a junior surgeon without robotic console experience. Post-operative complications were defined according to the Clavien grading system for surgical morbidity RESULTS: For groups 1 and 2 median age was 63 and 62 years, respectively; median pre-operative PSA level was 10 and 8, respectively; the median BMI was 24 and 25, respectively. The median operative time (OT) was 179 and 160 min, respectively (p > 0.05); and median blood loss was 217 and 346 ml, respectively (p = 0.04). The overall transfusion rate was 1.5% and two major complications were recorded in group 1 and four in group 2. CONCLUSIONS: RARP is safe and reproducible even during the initial learning curve. Overcoming the learning curve is multifactorial and is necessarily dependent on the surgeon. However, joining a well-trained team probably affects positively the performance of the surgeon. The value of expert centers to train new surgeons to RARP needs to be evaluated.

Assessing the complications of laparoscopic robot-assisted surgery: the case of radical prostatectomy.

BACKGROUND: A robot-assisted laparoscopic approach for radical prostatectomy (RALRP) is being adopted increasingly worldwide for the treatment of localized prostate cancer (CaP). Complications assessment is essential to the objective evaluation of any new procedure. This study aimed to assess the perioperative complications encountered during the implementation of a robot-assisted urologic surgery program. METHODS: A prospective data collection for all men with a diagnosis of CaP who underwent RALRP between 2005 and 2009 in our department was achieved. Together with perioperative data, all the perioperative complications encountered were specifically recorded, including robot dysfunctions. The RALRP was performed with the three-arm Da Vinci system using a transperitoneal approach with six ports. To assess the perioperative complications, the validated Clavien-Dindo classification of surgical procedures was used. Two surgeons were involved in these procedures. A modified Clavien-Dindo classification also was used to account for intraoperative complications. RESULTS: According to the Clavien-Dindo classification, 16 complications (6.7% complication rate) were recorded during the first 240 procedures. Besides postoperative complications, five procedures (2.1%) were directly affected by robot malfunctions without notable consequences for the patients. Considering these five additional complications, an 8.8% complication rate was recorded using a modified Clavien-Dindo classification. The main limitation of the study was its design restricted to RALRP procedures alone. The second limitation was that the authors' modified classification needs to be validated with a larger series and for different surgical procedures. CONCLUSIONS: The findings show that RALRP is a safe alternative to classical surgery and that the robotic approach is reliable. The authors believe that the reliability of technological devices should be systematically discussed when outcome analysis of a new procedure is performed.

New insights into the metal specificity of the Pseudomonas aeruginosa pyoverdine-iron uptake pathway.

Pyoverdine (PvdI) is the major siderophore secreted by Pseudomonas aeruginosa PAOI in order to get access to iron. After being loaded with iron in the extracellular medium, PvdI is transported across the bacterial outer membrane by the transporter, FpvAI. We used the spectral properties of PvdI to show that in addition to Fe(3+), this siderophore also chelates, but with lower efficiencies, all the 16 metals used in our screening. Afterwards, FpvAI at the cell surface binds Ag(+), Al(3+), Cd(2+), Co(2+), Cu(2+), Fe(3+), Ga(3+), Hg(2+), Mn(2+), Ni(2+) or Zn(2+) in complex with PvdI. We used Inductively Coupled Plasma-Atomic Emission Spectrometry to monitor metal uptake in P. aeruginosa: TonB-dependent uptake, in the presence of PvdI, was only efficient for Fe(3+). Cu(2+), Ga(3+), Mn(2+) and Ni(2+) were also transported into the cell but with lower uptake rates. The presence of Al(3+), Cu(2+), Ga(3+), Mn(2+), Ni(2+) and Zn(2+) in the extracellular medium induced PvdI production in P. aeruginosa. All these data allow a better understanding of the behaviour of the PvdI uptake pathway in the presence of metals other than iron: FpvAI at the cell surface has broad metal specificity at the binding stage and it is highly selective for Fe(3+) only during the uptake process.

Soil bioaugmentation by free and immobilized bacteria to reduce potentially phytoavailable cadmium.

Soil bioaugmentation was performed in soil pots to reduce the cadmium potentially available for plants. A Bacillus sp. (isolate ZAN-044) and a Streptomyces sp. (isolate R25) were compared, just as the inoculation technique, i.e., inoculum size, free or immobilized cells. After 3 weeks of a batch incubation, the potentially phytoavailable Cd was reduced, at the maximum, to a factor 14.1 and 4.3 with Bacillus sp. ZAN-044 and Streptomyces sp. R25, respectively. The two bacteria survived and colonized the soil. The immobilization technique did not improve the cell survival in the bioaugmented soil. The potentially phytoavailable Cd was positively (r(2)=+0.73) or negatively correlated (r(2)=-0.78) to the cell concentration in the sterilized soil bioaugmented with Bacillus sp. ZAN-044 or Streptomyces sp. R25, respectively. The major effect upon the phytoavailable Cd was the microorganism used and, to a lesser extent, the inoculum size and the culture technique.

Screening men for prostate cancer and colorectal cancer: is practice evidence-based?

INTRODUCTION: Controversy persists about whether men should be screened for prostate cancer. On the other hand, the benefit of colorectal cancer screening has been proven for men starting at age 50. We aimed to examine the rate of exposure to previous screening tests for prostate cancer and colorectal cancer in a cohort of men living in Quebec. MATERIALS AND METHODS: As part of an event promoting early prostate cancer detection, 347 men aged 50 to 69 without an established diagnosis of prostate cancer agreed to reply to questions in a previously validated questionnaire. The self-administered questionnaire, which asked about previous screening tests for prostate cancer and colorectal cancer, was completed on-site. RESULTS: Among men aged 50 to 69, previous exposure to a digital rectal examination (DRE), a prostate-specific antigen (PSA) test, a fecal occult blood test (FOBT), and sigmoidoscopy were reported by 132 men (62.9%), 73 men (34.8%), 37 men (17.6%), and 39 men (18.6%) , respectively. Across all age strata (< 50, 50-69, > or = 70 years), PSA and DRE testing were highest in men aged 50 to 69 and were 2- to 3-fold higher than screening tests for colorectal cancer. CONCLUSIONS: In this cohort of asymptomatic Canadian men, overall and age-stratified exposure to tests to detect colon cancer early is far from ideal. Conversely, far more men have been subjected to PSA testing and DRE. Patients should be informed of the benefits and risks of colorectal cancer screening and PSA testing.

Prostate specific-antigen distribution in asymptomatic Canadian men with no clinical evidence of prostate cancer.

OBJECTIVE: To examine prostate specific-antigen (PSA) levels and percentage free/total PSA (f/tPSA) distributions as well as digital rectal examination (DRE) profiles in asymptomatic Canadian men with no established prostate cancer diagnosis, as recent data indicate that a man's risk of developing prostate cancer is higher if his baseline PSA level is above the median for his age group. SUBJECTS AND METHODS: We used data obtained during an early prostate cancer-detection event. An invitation to an onsite DRE, PSA level and f/tPSA assessment was accepted by 313 men. Serum PSA level and f/tPSA were measured before the DRE. A suspicious DRE and/or PSA level of > or = 2.5 ng/mL or f/tPSA of < or = 15% represented indications for a systematic 12-core ultrasonography-guided prostate biopsy. RESULTS: Of all the 313 men, most (235, 75%) had PSA levels of 0.01-1.53 ng/mL and an f/tPSA of >15% (285, 91.1%). The median (range) PSA level was 0.8 (0-34.2) ng/mL and f/tPSA was 27.4 (6.7-100)%. Age-specific median PSA levels and f/tPSA were, respectively, 0.7, 0.9, 1.0, 1.5 ng/mL and 31%, 27%, 26%, 25% for men aged 40-49, 50-59, 60-69 and 70-79 years. A suspicious DRE was recorded in 55 (17.6%) men, with eight (8.8%), 26 (20.0%), 14 (20.6%), and seven (28.9%) having suspicious DRE findings according to above age categories. Overall, seven (2.2%) prostate cancers were detected. CONCLUSION: The median age-specific baseline PSA levels and f/tPSA represent valuable indicators of prostate cancer risk. The population-specific baseline median PSA level should not be >1.0 ng/mL and the baseline f/tPSA should be >30%. Men with values outside of these ranges should be considered at greater risk of prostate cancer.

Normal urinary and sexual function in men without evidence of prostate cancer from Montreal, Canada.

OBJECTIVE: To examine the rates of stress urinary incontinence (SUI) and erectile dysfunction (ED), and of associated bother, in men with no evidence of prostate cancer who participated in a prostate cancer-screening event. SUBJECTS AND METHODS: A cohort of 366 men with no established diagnosis of prostate cancer completed a questionnaire addressing SUI, ED and associated bother. Socio-economic status and presence of comorbidities were also examined. RESULTS: The mean (range) age of the men was 54.8 (33-80) years; 90% of the men (271) had no SUI, and 76% (231) reported no urinary bother. Conversely, 62% (189) reported some degree of ED and 27% (82) some degree of sexual bother. Urinary bother (P < 0.001), erectile function (P < 0.001), and sexual bother (P < 0.02) were associated with age. Of all the men, 36% had one or more comorbidities. Men with one or more comorbidities had worse erectile function than those men with no comorbidity (P < 0.05). CONCLUSION: Few studies address normative values of SUI and ED rates in men with no established diagnosis of prostate cancer. We quantified the rate of SUI and it was practically negligible. Conversely, some degree of ED affected most of the present screened population. These data may be used as baseline references to evaluate the magnitude of functional and bother detriments after various prostate treatments.

The 2002 AJCC pT2 substages confer no prognostic information on the rate of biochemical recurrence after radical prostatectomy.

INTRODUCTION: We examined the prognostic value of AJCC pT2 substages in prediction of biochemical recurrence (BCR) after radical prostatectomy (RP), in European patients. METHODS: A cohort of 1726 RP patients with pT2N0 prostate cancer (PCa) was studied. Multivariate Cox regression models addressed the association between either the 1997 or 1992/2002 pT2 substages after controlling for total PSA, primary and secondary pathologic Gleason scores and surgical margin status and time to PSA recurrence (PSA >0.1 and rising) after RP. Regression coefficients were then used to test the predictive accuracy of multivariate models in a nomogram setting. RESULTS: PSA recurrence occurred in 80 (4.6%) patients. Mean and median times to recurrence were respectively 28.9 and 24.4 months. In univariate analyses, neither the 1997 (p = 0.48) nor the 1992/2002 pT2 substages (p = 0.054) were predictive of recurrence. In multivariate analyses the lack of significance persisted (1997 p = 0.709; 1992/2002 p = 0.124). When either the 1997 or 1992/2002 pT2 substages were added to a multivariate nomogram without pT2 substage information, its accuracy respectively decreased by 0.8% and 1.1%. CONCLUSION: Our data indicate that pT2 substages offer no incremental value relative to pre-treatment total PSA, surgical margin status and pathologic Gleason scores. Therefore, it might be postulated that it is sufficient to confirm organ confinement according to Partin's pathologic staging.

Validation of 1997 Partin Tables' lymph node invasion predictions in men treated with radical prostatectomy in Montreal Quebec.

OBJECTIVE: The accuracy of 1997 Partin Tables' lymph node invasion (LNI) predictions exhibits important variability in different testing populations. We explored the LNI predictive accuracy in radical prostatectomy (RP) patients from Montreal, Canada. Moreover, we assessed the extent of change in predictive accuracy related to a modification of PSA coding from categorical to continuous. METHODS: We used pretreatment serum PSA, clinical stage, and biopsy Gleason sum from 537 men treated with RP to compare predicted and observed rates of LNI. Accuracy was quantified with receiver-operating characteristics curves. RESULTS: Accuracy was 0.760 in 369 evaluable patients, when categorically coded pretreatment PSA (0-4, 4.1-10, 10.1-20, 20.1+) was combined with clinical stage and biopsy Gleason sum. A 2.7% accuracy increase was noted when categorically coded PSA was replaced with continuously coded values. CONCLUSION: Partin Tables' LNI predictions showed comparable accuracy to a community-based sample from the United States (0.766), and to a recent, multi-institutional sample (0.740). However, accuracy was lower than reported in internal (0.818), and external (0.837) academic, validation cohorts. Accuracy of LNI predictions was appreciably higher, when continuously coded PSA was used.

Validation of prostate cancer index and SF-12 short forms.

BACKGROUND: Assessment of prostate cancer (PCa) specific and generic health-related quality-of-life (HRQOL) is frequently omitted due to several obstacles, such as respondent burden and infrastructure-related limitations. We attempted to reduce the number of items of two commonly used HRQOL assessment tools, namely the UCLA PCa Index (PCI) and the RAND SF-12, with the intent of generating the most parsimonious, yet psychometrically valid and reliable HRQOL assessment tool. METHODS: The PCI and SF-12 were administered to 2415 radical prostatectomy patients, and re-tested in a convenience sample of 35 men with PCa. Multivariate linear regression models defined the most predictive and item-reduced SF-12 and PCI item combinations. These were subjected to standard psychometric reliability and validity tests. RESULTS: The 8-item PCI sexual function (SF) scale was reduced to three items. The 5-item PCI urinary function (UF) scale was reduced to three items. The 6-item SF-12 mental health scale was reduced to three items, and the 6-item SF-12 physical scale was also reduced to three items. The total number of items was reduced from 27 to 12 (44%). The item-reduced scales accounted for over 85% of full-scale variance. All reliability and validity tests yielded highly satisfactory results. CONCLUSION: We developed SF-12 and PCI short-forms, which consist of 12 of 27 (44%) original items and can be completed by most men within 2 minutes. The short-forms represent a valid substitute for the full scales, as they provide over 85% of full-scale information and demonstrate excellent reliability statistics. The short forms have the potential for decreasing respondent burden and infrastructure-related requirements, which may in turn promote HRQOL assessment after radical prostatectomy.