New classes of radiometric and combined radiometric-geometric invariant descriptors.

Real images can contain geometric distortions as well as photometric degradations. Analysis and characterization of those images without recourse to either restoration or geometric standardization is of great importance for the computer vision community as those two processes are often ill-posed problems. To this end, it is necessary to implement image descriptors that make it possible to identify the original image in a simple way independently of the imaging system and imaging conditions. Ideally, descriptors that capture image characteristics must be invariant to the whole range of geometric distortions and photometric degradations, such as blur, that may affect the image. In this paper, we introduce two new classes of radiometric and/or geometric invariant descriptors. The first class contains two types of radiometric invariant descriptors. The first of these type is based on the Mellin transform and the second one is based on central moments. Both descriptors are invariant to contrast changes and to convolution with any kernel having a symmetric form with respect to the diagonals. The second class contains two subclasses of combined invariant descriptors. The first subclass includes central-moment-based descriptors invariant simultaneously to horizontal and vertical translations, to uniform and anisotropic scaling, to stretching, to convolution, and to contrast changes. The second subclass contains central-complex-moment-based descriptors that are simultaneously invariant to similarity transformation and to contrast changes. We apply these invariant descriptors to the matching of geometric transformed and/or blurred images. Experimental results confirm both the robustness and the effectiveness of the proposed invariants.

Preparation and characterization of new anti-PSMA monoclonal antibodies with potential clinical use.

Monoclonal antibodies with high specificity for prostate cancer tissue are of interest for diagnostic and therapeutic applications employing targeted therapy. The prostate-specific membrane antigen (PSMA) is a protein predominantly found in epithelial cells of prostate tissue origin and its expression correlates with tumor aggressiveness. Here, we report the development and characterization of new antibodies against PSMA. Murine monoclonal antibodies (MAb) were obtained by immunizing mice with a peptide corresponding to PSMA extracellular residues 490-500 -- GKSLYESWTKK (PSMA(490-500)). The MAbs react specifically to PSMA and to the prostate cancer cell line LNCaP with an affinity for PSMA in the low nanomolar range. This study also demonstrates the potential use of these antibodies for targeted drug delivery to prostate cancer cells. Nanomolar concentrations of PSMA-specific MAb in association with a molecule with cytotoxic potential were sufficient to allow for binding and uptake by LNCaP cells within minutes, leading to complete cell death within 3 days. These MAbs have potential clinical value in the development of diagnostic and therapeutic applications for prostate cancer.

Increased insulin, triglycerides, reactive oxygen species, and cardiac fibrosis in mice with a mutation in the helicase domain of the Werner syndrome gene homologue.

Werner Syndrome (WS) is a rare disorder characterized by the premature onset of a number of age-related diseases. The gene responsible for WS encodes a DNA helicase/exonuclease protein. Previously, we generated a mouse model lacking part of the helicase domain of the murine Wrn homologue. Mutant WrnDeltahel/Deltahel mice developed severe cardiac interstitial fibrosis in addition to tumors. Further analyses of these mice on the pure C57Bl/6 genetic background revealed abnormal increases in visceral fat deposition, fasting blood triglyceride and cholesterol levels followed by insulin resistance and high blood glucose levels. These phenotypes were more severe in mutant females than mutant males. In addition, adult mice had clear hemodynamic signs of aortic stenosis. All these symptoms appeared before the onset of cardiomyopathy and are known to cause heart failure. Interestingly, WrnDeltahel/Deltahel adult mice (but not juveniles) showed higher levels of serum and cardiac tissue reactive oxygen species followed in time by an increase in cardiac oxidative DNA damage, all this prior to cardiac fibrosis.

In vivo misregulation of genes involved in apoptosis, development and oxidative stress in mice lacking both functional Werner syndrome protein and poly(ADP-ribose) polymerase-1.

Werner syndrome (WS) is a rare disorder characterized by the premature onset of a number of age-related diseases. The gene responsible for WS is believed to be involved in different aspects of transcription, replication and/or DNA repair. The poly(ADP-ribose) polymerase-1 (PARP-1) enzyme is also involved in DNA repair and is known to affect transcription of several genes. In this study, we examined the expression profile of cells lacking the normal function of either or both enzymes. All mutant cells exhibited altered expression of genes normally responding to oxidative stress. Interestingly, more than 58% of misregulated genes identified in double mutant cells were not altered in cells with either the Wrn or PARP-1 mutation alone. So, the impact on gene expression profile when both Wrn and PARP-1 are mutated was greater than a simple addition of individual mutant genotype. In addition, double mutant cultured cells showed major misregulation of genes involved in apoptosis, cell cycle control, embryonic development, metabolism and signal transduction. More importantly, in vivo analyses of double mutant mice have confirmed the increased apoptosis and the developmental defects in embryos as well as the major increase in intracellular phosphorylation and oxidative DNA damage in adult tissues. They also exhibited a progressive increase in oxidative stress with age. Thus, a major result of this study is that changes in expression of several genes and physiological functions identified in vitro were confirmed in mouse embryonic and adult tissues.