Magdi Mohamed Mashly

Bilharzial bladder cancer is the most common malignant neoplasm in Egypt, also occurring with a high incidence in other regions of the Middle East and East Africa. In a previous study, using centromere probes specific for chromosomes 3, 4, 7-11, 16, and 17, we demonstrated that monosomy of chromosome 9 (48.4%), and numerical aberrations of chromosome 17 (19.4%) were the most common observed imbalances. The present study extends the establishment of the baseline cytogenetic profile of this type of malignancy. Interphase cytogenetics by fluorescence in situ hybridization with the use of a panel of centromere-associated DNA probes for chromosomes 1, 2, 5, 6, 12, 13/21, 14, 15, 18, 19, 20, X, and Y was performed on paraffin-embedded bladder specimens from 25 Egyptian patients affected with bilharzial bladder cancer. No numerical aberrations were detected in the 25 cases for chromosomes 1, 2, 5, 6, 12, 13/21, 14, 15, 18, 19, 20, and X. However, loss of chromosome Y was observed in 7 of the 17 male cases studied (41.2%). No significant correlation was observed between loss of the Y chromosome and any of the different clinicopathologic characteristics of these cases. These data suggest that loss of the Y chromosome is the second frequent event that can occur in bilharzial bladder cancer. A molecular genetic model of bilharzial bladder cancer is evolving. Copyright (C) 1999 Elsevier Science Inc.

Bilharzial bladder cancer is the most common malignant neoplasm in Egypt, also occurring with a high incidence in other regions of the Middle East and East Africa. In a previous study, using centromere probes specific for chromosomes 3, 4, 7-11, 16, and 17, we demonstrated that monosomy of chromosome 9 (48.4%), and numerical aberrations of chromosome 17 (19.4%) were the most common observed imbalances. The present study extends the establishment of the baseline cytogenetic profile of this type of malignancy. Interphase cytogenetics by fluorescence in situ hybridization with the use of a panel of centromere-associated DNA probes for chromosomes 1, 2, 5, 6, 12, 13/21, 14, 15, 18, 19, 20, X, and Y was performed on paraffin-embedded bladder specimens from 25 Egyptian patients affected with bilharzial bladder cancer. No numerical aberrations were detected in the 25 cases for chromosomes 1, 2, 5, 6, 12, 13/21, 14, 15, 18, 19, 20, and X. However, loss of chromosome Y was observed in 7 of the 17 male cases studied (41.2%). No significant correlation was observed between loss of the Y chromosome and any of the different clinicopathologic characteristics of these cases. These data suggest that loss of the Y chromosome is the second frequent event that can occur in bilharzial bladder cancer. A molecular genetic model of bilharzial bladder cancer is evolving. Copyright (C) 1999 Elsevier Science Inc.

A method has been developed to accurately determine the turbulent burning velocity in planar turbulent premixed flames stabilized by a low swirl. Six lean methane/air flames have been investigated covering the flamelet as well as the thin reaction zones regime. The probability of finding the instantaneous flame front is measured together with the velocity field by combining simultaneously OH-laser-induced predissociative fluorescence with either Rayleigh thermometry or particle image velocimetry (PIV). It is demonstrated that the turbulent flame brush thickness is independent of v'/sL and that the turbulent burning velocity agrees with predictions from a model equation for the flame surface area ratio using the level set approach. The measurements of the two-dimensional flowfield show a recirculation zone downstream of the flame stabilization area. This exhibits a comparable flow pattern to stagnation point flames. However, mean strain rates are much lower since the flames stabilize close to the burner exit, and the flame is not influenced by the recirculation zone. A comparison of the root-mean-square velocities obtained from Laser-Doppler Amemometry measurements to those determined by PIV show a good agreement. It can be shown that turbulence is attenuated in the flame zone and only moderately increased behind it.

A method has been developed to accurately determine the turbulent burning velocity in planar turbulent premixed flames stabilized by a low swirl. Six lean methane/air flames have been investigated covering the flamelet as well as the thin reaction zones regime. The probability of finding the instantaneous flame front is measured together with the velocity field by combining simultaneously OH-laser-induced predissociative fluorescence with either Rayleigh thermometry or particle image velocimetry (PIV). It is demonstrated that the turbulent flame brush thickness is independent of ν/sL and that the turbulent burning velocity agrees with predictions from a model equation for the flame surface area ratio using the level set approach. The measurements of the two-dimensional flowfield show a recirculation zone downstream of the flame stabilization area. This exhibits a comparable flow pattern to stagnation point flames. However, mean strain rates are much lower since the flames stabilize close to the burner exit, and the flame is not influenced by the recirculation zone. A comparison of the root-mean-square velocities obtained from Laser-Doppler Amemometry measurements to those determined by PIV show a good agreement. It can be shown that turbulence is attenuated in the flame zone and only moderately increased behind it.