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Selective Treatment (selective + treatment)
Selected AbstractsSelective Treatment of Cancer: Synthesis, Biological Evaluation and Structural Elucidation of Novel Analogues of the Antibiotic CC-1065 and the DuocarmycinsCHEMISTRY - A EUROPEAN JOURNAL, Issue 16 2007Abstract Novel diastereomerically pure ,- D -galactosidic prodrugs (+)- 12,a,e of the cytotoxic antibiotics CC-1065 and the duocarmycins were prepared for an antibody directed enzyme prodrug therapy (ADEPT) using 4 as a substrate via a radical cyclization to give rac - 5 and rac - 6 followed by a chromatographic resolution of the enantiomers of rac - 5, glycosidation and linkage to the DNA-binding units 10,a,e. These only slightly toxic compounds can be toxified enzymatically by an antibody,,- D -galactosidase conjugate at the surface of malignant cells to give the cytotoxic drugs, which then alkylate DNA. The new prodrugs were tested in in vitro cytotoxicity assays showing excellent QIC50 values of 4800 and 4300 for (+)- 12,a and (+)- 12,b, respectively. The absolute configuration of precursor (+)- 5 was determined by comparison of the experimental CD spectrum with the theoretically predicted CD spectra and by X-ray structure analysis. [source] Targeting of the retinal pigment epithelium (RPE) by means of a rapidly scanned continuous wave (CW) laser beamLASERS IN SURGERY AND MEDICINE, Issue 4 2003Ralf Brinkmann Abstract Background and Objectives Selective treatment of the retinal pigment epithelium (RPE) by repetitively applying green ,s-laser pulses is a new method for retinal diseases associated with a degradation of the RPE, which spares the neural retina. We investigated an alternative approach to realize repetitive ,s-laser exposure by rapidly scanning a continuous wave (CW)-laser beam across the RPE. Study Design/Materials and Methods An Ar+ laser beam (514 nm) with a diameter of 18.75 ,m was repetitively scanned across porcine RPE samples in vitro providing an irradiation time of 1.6 ,s per point on the central scan axis. RPE cell damage was investigated by means of the fluorescence viability assay Calcein-AM. Results The ED50 cell damage is 305 mJ/cm2 when applying 10 scans with a repetition rate of 500 Hz. The threshold decreases with the number of scans, a saturation was found at 135 mJ/cm2 with more than 500 exposures applied. The depth of focus in beam direction is 350 ,m, defined by an increase of the threshold radiant exposure by 20%. Conclusions Targeting of pigmented cells with high local resolution has been proved with a laser-scanning device. Looking ahead selective RPE-treatment, the adaptation of a laser-scanning device on a slit-lamp or into a modified retina angiograph seems to be an attractive alternative to the pulsed ,s laser device. Lasers Surg. Med. 32:252,264, 2003. © 2003 Wiley-Liss, Inc. [source] Advancing the diagnosis and treatment of hepatocellular carcinomaLIVER TRANSPLANTATION, Issue 4 2005J. Wallis Marsh MD We analyzed global gene expression patterns of 91 human hepatocellular carcinomas (HCCs) to define the molecular characteristics of the tumors and to test the prognostic value of the expression profiles. Unsupervised classification methods revealed two distinctive subclasses of HCC that are highly associated with patient survival. This association was validated via 5 independent supervised learning methods. We also identified the genes most strongly associated with survival by using the Cox proportional hazards survival analysis. This approach identified a limited number of genes that accurately predicted the length of survival and provides new molecular insight into the pathogenesis of HCC. Tumors from the low survival subclass have strong cell proliferation and antiapoptosis gene expression signatures. In addition, the low survival subclass displayed higher expression of genes involved in ubiquitination and histone modification, suggesting an etiological involvement of these processes in accelerating the progression of HCC. In conclusion, the biological differences identified in the HCC subclasses should provide an attractive source for the development of therapeutic targets (e.g., HIF1a) for selective treatment of HCC patients. Supplementary material for this article can be found on the HEPATOLOGY Web site (http://interscience.wiley.com/jpages/0270-9139/suppmat/index.html) Copyright 2004 American Association for the Study of Liver Diseases. Hepatology. 2004 Sep;40(3):667,76. [source] Neo-Adjuvant Hormonal TherapyTHE BREAST JOURNAL, Issue 3 2008Marcia Valenzuela MD Abstract:, Neo-adjuvant endocrine therapy has opened new alternatives for locally advanced breast cancer. Such therapy, which has permitted us to expand the treatment role of neo-adjuvant therapies, may be of great benefit to patient groups such as the elderly, those not suited for chemotherapy, and those whose response may not be optimal. This therapy also may be able to help us identify agents that could improve outcomes in the adjuvant setting as well as possible biologic predictors for outcome. The latest generation of endocrine therapy for breast cancer, aromatase inhibitors, has proved superior to tamoxifen in terms of toxicity and efficacy in the adjuvant setting and is currently being studied in other clinical trials. Current findings indicate that these agents are less toxic and better tolerated than neo-adjuvant chemotherapy and that third-generation anti-hormomal therapy offers improved tumor response compared with tamoxifen, which has resulted in increased breast conserving surgery. Biomarker findings of improved response in tumors that are both estrogen receptor positive and HER-2 positive as well as progesterone receptor positivity only will be important for planning future selective treatment and clinical trials. [source] CCL21 overexpressed on lymphatic vessels drives thymic hyperplasia in myasthenia,ANNALS OF NEUROLOGY, Issue 4 2009Sonia Berrih-Aknin PhD Objective Myasthenia gravis (MG), a neuromuscular disease mediated by anti-acetylcholine receptor (AChR) autoantibodies, is associated with thymic hyperplasia characterized by ectopic germinal centers that contain pathogenic antibody-producing B cells. Our thymic transcriptome study demonstrated increased expression of CCL21, a recruiter of immune cells. Accordingly, we are investigating its implication in MG pathogenesis. Methods The expression of CCL21 and its CCR7 receptor was analyzed by enzyme-linked immunosorbent assay and fluorescence-activated cell sorting, respectively. Chemotaxis of T and B cells to CCL21 was measured by transwell assay. The nature of the thymic cells overexpressing CCL21 was investigated by immunochemistry and laser-capture microdissection combined with real-time PCR. Results We demonstrate that CCL21 is overexpressed specifically in hyperplastic MG thymuses, whereas there is no variation in CCR7 levels on blood cells. We show that although CCL21 attracts both human T and B cells, it acts more strongly on naive B cells. CCL21 overexpression is normalized in corticoid-treated MG patients, suggesting that targeting this chemokine could represent a new selective treatment, decreasing the abnormal peripheral lymphocyte recruitment. Moreover, we locate protein and messenger RNA overexpression of CCL21 to specific endothelial vessels. Investigation of the nature of these vessels demonstrated different angiogenic processes in MG thymuses: high endothelial venule angiogenesis and lymphangiogenesis. Unexpectedly, CCL21 overexpression originates from afferent lymphatic endothelial vessels. Interpretation We postulate that thymic overexpression of CCL21 on specialized lymphatic vessels results in abnormal peripheral lymphocyte recruitment, bringing naive B cells in contact with the inflammatory environment characteristic of MG thymuses, where they can be sensitized against AChR. Ann Neurol 2009;66:521,531 [source] Selective Inhibition of Hepatoma Cells Using Diphtheria Toxin A under the Control of the Promoter/Enhancer Region of the Human ,-Fetoprotein GeneCANCER SCIENCE, Issue 3 2000Michito Kunitomi We constructed a plasmid containing human ,-fetoprotein (AFP) promoter/enhancer to direct the cell type-specific expression of diphtheria toxin fragment A (DTA), designated as pAF-DTA, to AFP-producing hepatocellular carcinoma cells. The transfection was carried out with cationic liposomes (DMRIE-C) and the expression of the DTA gene was confirmed by a northern blot analysis. When pAF-DTA was transfected, the growth of AFP-positive HuH-7 cells was inhibited, whereas growth inhibition was not observed in AFP-negative MKN45 cells. In this experiment, the secretion of AFP was similarly suppressed, but the secretion of carcinoembryonic antigen from MKN45 was not altered. pAF-DTA could also exert its growth inhibitory effect on PLC, a cell line with a low level of AFP. However, no inhibitory effect of pAF-DTA was observed on the proliferation of primary hepatocyte cells. Furthermore, transfection experiments in which HuH-7 and splenic stromal cells were co-cultured revealed the growth inhibition by pAF-DTA to be selective in HuH-7 cells. Finally, the growth of HuH-7 transplanted on BALB/c nu/nu mice was inhibited by the direct injection of pAF-DTA/liposome complex into a tumor mass. These results suggest that use of pAF-DTA may be potentially useful as a novel approach for the selective treatment of tumor cells producing AFP even at low levels, without affecting other types of cells. [source] | ||||||||||