and Objectives: To assess the pathological outcomes following radical prostatectomy (RP) in men w... more and Objectives: To assess the pathological outcomes following radical prostatectomy (RP) in men with favorable-risk PCa diagnosed on their first/initial (IBPx) compared to men who were diagnosed on a subsequent/repeat (RPBx) prostate biopsy. We identified 422 patients who met National Cancer Comprehensive Network (NCCN) very-low (N = 199) and low-risk (N = 223) PCa who instead underwent RP. In each risk category we compared adverse pathologic outcomes defined as Gleason score (GS) upgrading, extraprostatic extension (EPE), seminal vesicle invasion (SVI), and positive surgical margins between men diagnosed IPBx versus RPBx after a negative biopsy(-ies). There were no significant differences in the baseline clinical and demographic characteristics between groups. However, men who were diagnosed on IPBx demonstrated a higher median maximum cancer % per single core (p < 0.001) and higher median % of positive cores (p < 0.001). Compared to RPBx, men diagnosed on IPBx had a higher G...
A Numerical Solution for Quasistatic Viscoelastic Frictional Contact Problems. [Journal of Tribol... more A Numerical Solution for Quasistatic Viscoelastic Frictional Contact Problems. [Journal of Tribology 130, 011012 (2008)]. Fatin F. Mahmoud, Mem. ASME, Ahmed G. El-Shafei, Amal E. Al-Shorbagy, Alaa A. Abdel Rahman. Abstract. ...
Journal of endourology / Endourological Society, Jan 20, 2015
To evaluate the oncological and functional outcomes of primary cryotherapy in men with clinically... more To evaluate the oncological and functional outcomes of primary cryotherapy in men with clinically localized, high-grade prostate cancer. We included all men with biopsy Gleason score ≥8, localized (cT1-2) disease with a serum prostate-specific antigen (PSA) ≤50 ng/mL from the Cryo On-Line Data (COLD) registry. The primary outcome was biochemical progression free survival (BPFS) as defined by the Phoenix criteria (nadir PSA +2 ng/mL). Secondary outcomes of continence (defined as strictly no leak) and potency (able to have intercourse) were patient reported. Factors influencing BPFS were evaluated individually using Kaplan Meier and in a multivariate model using Cox regression. Altogether, 300 men were included for analysis. The median follow-up was 18.2 months (mean 28.4) and median BPFS was 69.8 months. Based on Kaplan-Meier analysis, the estimated 2- and 5-year BPFS rate was 77.2% and 59.1%, respectively. Neoadjuvant hormonal therapy was administered to 41% of men and this tended t...
To create a predictive nomogram for biochemical failure following primary whole-gland cryoablatio... more To create a predictive nomogram for biochemical failure following primary whole-gland cryoablation of the prostate for localized prostate cancer (LPCa). We retrospectively analyzed 2,242 patients from the Cryo On-Line Database (COLD) who were treatment naive and had undergone primary whole gland cryoablation of the prostate for biopsy-confirmed LPCa. Kaplan-Meier (KM) curves estimating 5 year biochemical progression-free survival (bPFS) were generated. Multivariable Cox proportional hazards analysis (CoxPH) was performed in order to construct the nomogram. The nomogram was internally validated using the bootstrap technique. Overall, the KM estimated 5 year bPFS was 72.8%. Stratified by D'Amico risk, The KM estimated 5 year bPFS was 82.6%, 71.1%, and 57.8% for low-, intermediate-, and high-risk groups, respectively. Statistically significant predictors of biochemical outcomes from CoxPH analysis were pre-treatment prostate specific antigen (PTPSA) (P < 0.001), total prostate v...
To investigate whether there is benefit with a longer acting oral fluoroquinolone, we compared th... more To investigate whether there is benefit with a longer acting oral fluoroquinolone, we compared the rate of infection after transrectal ultrasound-guided prostate biopsy between 2 prophylactic antibiotic regimens: ciprofloxacin vs levofloxacin, each combined with an aminoglycoside (AG). A retrospective review was performed of all transrectal ultrasound-guided prostate biopsies from September 2011 to January 2013. Initially our regimen entailed 1 dose of 500-mg ciprofloxacin and an AG. In June 2012, we switched to 1 dose of 750-mg levofloxacin and an AG. Infections were categorized as severe if requiring hospital admission, overnight observation, or emergency room treatment for fever or chills. Those treated as an outpatient were defined as mild. Of 1189 total biopsies, the total infection rate was 3.18% (17 of 535) in the ciprofloxacin group and 2.14% (14 of 654) in the levofloxacin group (P = .26). The rate of mild infection was 0.75% (4 of 535) in the ciprofloxacin group and 1.22% ...
ABSTRACT A finite element computational procedure for the accurate analysis of quasistatic thermo... more ABSTRACT A finite element computational procedure for the accurate analysis of quasistatic thermorheological complex structures response is developed. The geometrical nonlinearity, arising from large displacements and rotations (but small strains), is accounted for by the total Lagrangian description of motion. The Schapery&#39;s nonlinear single-integral viscoelastic constitutive model is modified for a time-stress-temperature-dependent behavior. The nonlinear thermo-viscoelastic constitutive equations are incrementalized leading to a recursive relationship and thereby the resulting finite element equations necessitate data storage from the previous time step only, and not the entire deformation history. The Newton-Raphson iterative scheme is employed to obtain a converged solution for the non-linear finite element equations. The developed numerical model is verified with the previously published works and a good agreement with them is found. The applicability of the developed model is demonstrated by analyzing two examples with different thermal/mechanical loading histories.
ABSTRACT This paper presents a comprehensive computational model for predicting the nonlinear res... more ABSTRACT This paper presents a comprehensive computational model for predicting the nonlinear response of frictional viscoelastic contact systems under thermo-mechanical loading and experience geometrical nonlinearity. The nonlinear viscoelastic constitutive model is expressed by an integral form of a creep function, whose elastic and time-dependent properties change with stresses and temperatures. The thermo-viscoelastic behavior of the contacting bodies is assumed to follow a class of thermo-rheologically complex materials. An incremental-recursive formula for solving the nonlinear viscoelastic integral equation is derived. Such formula necessitates data storage only from the previous time step. The contact problem as a variational inequality constrained model is handled using the Lagrange multiplier method for exact satisfaction of the inequality contact constraints. A local nonlinear friction law is adopted to model friction at the contact interface. The material and geometrical nonlinearities are modeled in the framework of the total Lagrangian formulation. The developed model is verified using available benchmarks. The effectiveness and accuracy of the developed computational model is validated by solving two thermo-mechanical contact problems with different natures. Moreover, obtained results show that the mechanical properties and the class of thermo-rheological behavior of the contacting bodies as well as the coefficient of friction have significant effects on the contact response of nonlinear thermo-viscoelastic materials.
STLE/ASME 2008 International Joint Tribology Conference, 2008
Effect of Material Characteristics on Viscoelastic Frictionless Contact Configuration. [ASME Conf... more Effect of Material Characteristics on Viscoelastic Frictionless Contact Configuration. [ASME Conference Proceedings 2008, 565 (2008)]. Fatin F. Mahmoud, Ahmed G. El-Shafei, Mohamed A. Attia. Abstract. The tribological status ...
To identify the ability of transrectal saturation prostate biopsy (SPBx) as the initial diagnosti... more To identify the ability of transrectal saturation prostate biopsy (SPBx) as the initial diagnostic approach to reduce the likelihood of finding previously unrecognized prostate cancer (PCa) during repeat prostate biopsy. We reviewed PCa detection in 561 men who underwent first repeat SPBx after initial negative biopsy between March 2002 and April 2012. We divided the patients on the basis of the number of cores retrieved on initial biopsy (group 1, initial negative SPBx [n = 81] and group 2, initial negative extended prostate biopsy [n = 480]). The yield of repeat SPBx was compared between the 2 groups. Insignificant PCa and low-risk PCa were defined according to Epstein criteria and D&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;Amico risk criteria, respectively. PCa detection on first repeat SPBx was 43.1% lower in group 1 (19.8% vs 34.8%; P = .008). Moreover, lower rate of significant PCa (31.3% vs 74.3%; P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;.001) and intermediate- and/or high-risk PCa (25.0% vs 50.9%; P = .048) in group 1. Multivariate analysis confirmed that initial negative SPBx decreased PCa detection on first repeat SPBx (odds ratio = 0.41, 95% confidence interval 0.22-0.78). Men whose initial biopsy was per transrectal saturation technique were less likely to have cancer identified during repeat biopsy. Furthermore, PCa diagnosed after negative initial SPBx was much more likely to be clinically insignificant. These findings suggest that SPBx may be less likely to miss clinically significant cancer during initial prostate biopsy. If confirmed in other studies, this suggests that initial biopsy by saturation technique may eliminate the need for most men to undergo repeat biopsy.
and Objectives: To assess the pathological outcomes following radical prostatectomy (RP) in men w... more and Objectives: To assess the pathological outcomes following radical prostatectomy (RP) in men with favorable-risk PCa diagnosed on their first/initial (IBPx) compared to men who were diagnosed on a subsequent/repeat (RPBx) prostate biopsy. We identified 422 patients who met National Cancer Comprehensive Network (NCCN) very-low (N = 199) and low-risk (N = 223) PCa who instead underwent RP. In each risk category we compared adverse pathologic outcomes defined as Gleason score (GS) upgrading, extraprostatic extension (EPE), seminal vesicle invasion (SVI), and positive surgical margins between men diagnosed IPBx versus RPBx after a negative biopsy(-ies). There were no significant differences in the baseline clinical and demographic characteristics between groups. However, men who were diagnosed on IPBx demonstrated a higher median maximum cancer % per single core (p < 0.001) and higher median % of positive cores (p < 0.001). Compared to RPBx, men diagnosed on IPBx had a higher G...
A Numerical Solution for Quasistatic Viscoelastic Frictional Contact Problems. [Journal of Tribol... more A Numerical Solution for Quasistatic Viscoelastic Frictional Contact Problems. [Journal of Tribology 130, 011012 (2008)]. Fatin F. Mahmoud, Mem. ASME, Ahmed G. El-Shafei, Amal E. Al-Shorbagy, Alaa A. Abdel Rahman. Abstract. ...
Journal of endourology / Endourological Society, Jan 20, 2015
To evaluate the oncological and functional outcomes of primary cryotherapy in men with clinically... more To evaluate the oncological and functional outcomes of primary cryotherapy in men with clinically localized, high-grade prostate cancer. We included all men with biopsy Gleason score ≥8, localized (cT1-2) disease with a serum prostate-specific antigen (PSA) ≤50 ng/mL from the Cryo On-Line Data (COLD) registry. The primary outcome was biochemical progression free survival (BPFS) as defined by the Phoenix criteria (nadir PSA +2 ng/mL). Secondary outcomes of continence (defined as strictly no leak) and potency (able to have intercourse) were patient reported. Factors influencing BPFS were evaluated individually using Kaplan Meier and in a multivariate model using Cox regression. Altogether, 300 men were included for analysis. The median follow-up was 18.2 months (mean 28.4) and median BPFS was 69.8 months. Based on Kaplan-Meier analysis, the estimated 2- and 5-year BPFS rate was 77.2% and 59.1%, respectively. Neoadjuvant hormonal therapy was administered to 41% of men and this tended t...
To create a predictive nomogram for biochemical failure following primary whole-gland cryoablatio... more To create a predictive nomogram for biochemical failure following primary whole-gland cryoablation of the prostate for localized prostate cancer (LPCa). We retrospectively analyzed 2,242 patients from the Cryo On-Line Database (COLD) who were treatment naive and had undergone primary whole gland cryoablation of the prostate for biopsy-confirmed LPCa. Kaplan-Meier (KM) curves estimating 5 year biochemical progression-free survival (bPFS) were generated. Multivariable Cox proportional hazards analysis (CoxPH) was performed in order to construct the nomogram. The nomogram was internally validated using the bootstrap technique. Overall, the KM estimated 5 year bPFS was 72.8%. Stratified by D'Amico risk, The KM estimated 5 year bPFS was 82.6%, 71.1%, and 57.8% for low-, intermediate-, and high-risk groups, respectively. Statistically significant predictors of biochemical outcomes from CoxPH analysis were pre-treatment prostate specific antigen (PTPSA) (P < 0.001), total prostate v...
To investigate whether there is benefit with a longer acting oral fluoroquinolone, we compared th... more To investigate whether there is benefit with a longer acting oral fluoroquinolone, we compared the rate of infection after transrectal ultrasound-guided prostate biopsy between 2 prophylactic antibiotic regimens: ciprofloxacin vs levofloxacin, each combined with an aminoglycoside (AG). A retrospective review was performed of all transrectal ultrasound-guided prostate biopsies from September 2011 to January 2013. Initially our regimen entailed 1 dose of 500-mg ciprofloxacin and an AG. In June 2012, we switched to 1 dose of 750-mg levofloxacin and an AG. Infections were categorized as severe if requiring hospital admission, overnight observation, or emergency room treatment for fever or chills. Those treated as an outpatient were defined as mild. Of 1189 total biopsies, the total infection rate was 3.18% (17 of 535) in the ciprofloxacin group and 2.14% (14 of 654) in the levofloxacin group (P = .26). The rate of mild infection was 0.75% (4 of 535) in the ciprofloxacin group and 1.22% ...
ABSTRACT A finite element computational procedure for the accurate analysis of quasistatic thermo... more ABSTRACT A finite element computational procedure for the accurate analysis of quasistatic thermorheological complex structures response is developed. The geometrical nonlinearity, arising from large displacements and rotations (but small strains), is accounted for by the total Lagrangian description of motion. The Schapery&#39;s nonlinear single-integral viscoelastic constitutive model is modified for a time-stress-temperature-dependent behavior. The nonlinear thermo-viscoelastic constitutive equations are incrementalized leading to a recursive relationship and thereby the resulting finite element equations necessitate data storage from the previous time step only, and not the entire deformation history. The Newton-Raphson iterative scheme is employed to obtain a converged solution for the non-linear finite element equations. The developed numerical model is verified with the previously published works and a good agreement with them is found. The applicability of the developed model is demonstrated by analyzing two examples with different thermal/mechanical loading histories.
ABSTRACT This paper presents a comprehensive computational model for predicting the nonlinear res... more ABSTRACT This paper presents a comprehensive computational model for predicting the nonlinear response of frictional viscoelastic contact systems under thermo-mechanical loading and experience geometrical nonlinearity. The nonlinear viscoelastic constitutive model is expressed by an integral form of a creep function, whose elastic and time-dependent properties change with stresses and temperatures. The thermo-viscoelastic behavior of the contacting bodies is assumed to follow a class of thermo-rheologically complex materials. An incremental-recursive formula for solving the nonlinear viscoelastic integral equation is derived. Such formula necessitates data storage only from the previous time step. The contact problem as a variational inequality constrained model is handled using the Lagrange multiplier method for exact satisfaction of the inequality contact constraints. A local nonlinear friction law is adopted to model friction at the contact interface. The material and geometrical nonlinearities are modeled in the framework of the total Lagrangian formulation. The developed model is verified using available benchmarks. The effectiveness and accuracy of the developed computational model is validated by solving two thermo-mechanical contact problems with different natures. Moreover, obtained results show that the mechanical properties and the class of thermo-rheological behavior of the contacting bodies as well as the coefficient of friction have significant effects on the contact response of nonlinear thermo-viscoelastic materials.
STLE/ASME 2008 International Joint Tribology Conference, 2008
Effect of Material Characteristics on Viscoelastic Frictionless Contact Configuration. [ASME Conf... more Effect of Material Characteristics on Viscoelastic Frictionless Contact Configuration. [ASME Conference Proceedings 2008, 565 (2008)]. Fatin F. Mahmoud, Ahmed G. El-Shafei, Mohamed A. Attia. Abstract. The tribological status ...
To identify the ability of transrectal saturation prostate biopsy (SPBx) as the initial diagnosti... more To identify the ability of transrectal saturation prostate biopsy (SPBx) as the initial diagnostic approach to reduce the likelihood of finding previously unrecognized prostate cancer (PCa) during repeat prostate biopsy. We reviewed PCa detection in 561 men who underwent first repeat SPBx after initial negative biopsy between March 2002 and April 2012. We divided the patients on the basis of the number of cores retrieved on initial biopsy (group 1, initial negative SPBx [n = 81] and group 2, initial negative extended prostate biopsy [n = 480]). The yield of repeat SPBx was compared between the 2 groups. Insignificant PCa and low-risk PCa were defined according to Epstein criteria and D&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;Amico risk criteria, respectively. PCa detection on first repeat SPBx was 43.1% lower in group 1 (19.8% vs 34.8%; P = .008). Moreover, lower rate of significant PCa (31.3% vs 74.3%; P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;.001) and intermediate- and/or high-risk PCa (25.0% vs 50.9%; P = .048) in group 1. Multivariate analysis confirmed that initial negative SPBx decreased PCa detection on first repeat SPBx (odds ratio = 0.41, 95% confidence interval 0.22-0.78). Men whose initial biopsy was per transrectal saturation technique were less likely to have cancer identified during repeat biopsy. Furthermore, PCa diagnosed after negative initial SPBx was much more likely to be clinically insignificant. These findings suggest that SPBx may be less likely to miss clinically significant cancer during initial prostate biopsy. If confirmed in other studies, this suggests that initial biopsy by saturation technique may eliminate the need for most men to undergo repeat biopsy.
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