Pic Of The Day
Posted by rob on July 21, 2005 under Uncategorized | 
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Protesters rallying against corruption raise their painted hands in the air in Lima.
Noonan Syndrome and Related Disorders: Genetics and Pathogenesis.
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Tartaglia M, Gelb BD
Annu Rev Genomics Hum Genet. 2005 Apr 13;
Noonan syndrome is a pleiomorphic autosomal dominant disorder with short stature, facial dysmorphia, webbed neck, and heart defects. In the past decade, progress has been made in elucidating the pathogenesis of this disorder using a positional cloning approach. Noonan syndrome is now known to be a genetically heterogeneous disorder with nearly one half of cases caused by gain-of-function mutations in PTPN11, the gene encoding the protein tyrosine phosphatase SHP-2. Similar germ line mutations cause two related genetic disorders, Noonan-like disorder with multiple giant cell lesion syndrome and LEOPARD syndrome, and somatic PTPN11 mutations can underlie certain pediatric hematopoietic malignancies, including juvenile myelomonocytic, acute lymphoblastic, and acute myelogenous leukemias. A mouse model of PTPN11-related Noonan syndrome was recently generated, providing a reagent for studying disease pathogenesis in greater depth as well as experimenting with novel therapeutic strategies. Expected online publication date for the Annual Review of Genomics and Human Genetics Volume 6 is August 30, 2005. Please see http://www.annualreviews.org/catalog/pub_dates.asp for revised estimates.
Noonan Syndrome and Related Disorders: Genetics and Pathogenesis.
Genomics in myeloid leukemias: an array of possibilities.
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Bullinger L, Dã Hner H, Pollack JR
Rev Clin Exp Hematol. 2005 Jun ; 9(1): E2
Myeloid leukemias are clonal hematopoietic stem cell disorders characterized either by proliferation of one or more of the myeloid lineages (chronic myelogenous leukemia) or by clonal expansion of myeloid blasts (acute myeloid leukemia). Over the past several years our knowledge of these hematologic malignancies has increased tremendously. The result is a classification that incorporates morphologic, immunophenotypic, genetic and clinical features in an attempt to define biologically and clinically relevant entities. Nevertheless, in many tumor subtypes the pathogenic event is still unknown. Furthermore, well-defined leukemia subgroups exhibit considerable heterogeneity, arousing the suspicion that several molecularly distinct subtypes might exist within the same cytogenetic category. Therefore, an ideal classification system would ultimately be based on the underlying molecular pathogenesis, but such knowledge is not yet available. However, by surveying the expression levels of thousands of genes in parallel, DNA microarrays have recently contributed to an increasingly refined molecular taxonomy of myeloid disorders. This powerful technology is becoming well established and has been used to diagnosis cancer and predict clinical outcome, to discover novel tumor subclasses, to gain insights into pathogenesis, and to identify new therapeutic targets. While many challenges remain ahead, genomic technologies have already demonstrated tremendous potential. We expect whole genome approaches will significantly contribute to a better understanding of the pathogenesis and result in a refined molecular classification of myeloid leukemias.
Histiocytoid Sweet syndrome: a dermal infiltration of immature neutrophilic granulocytes.
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Requena L, Kutzner H, Palmedo G, Pascual M, Fernández-Herrera J, Fraga J, García-Díez A, Yus ES
Arch Dermatol. 2005 Jul ; 141(7): 834-42
OBJECTIVE: To describe a series of 41 patients with fresh lesions of Sweet syndrome in which the histopathologic study demonstrated an inflammatory infiltrate mostly composed of histiocytoid mononuclear cells. DESIGN: Histopathologic, immunohistochemical, and cytogenetic studies of the inflammatory infiltrate in a case series of histiocytoid Sweet syndrome. SETTING: University departments of dermatology and a private laboratory of dermatopathology. METHODS: Conventional histopathologic study as well as immunohistochemical investigations were performed using the alkaline phosphatase antialkaline phosphatase technique with a large panel of antibodies. In some cases, fluorescent in situ hybridization studies were performed to investigate the presence of the bcr/abl gene fusion. RESULTS: Immunohistochemical studies demonstrated that most cells of the infiltrate showed immunoreactivity for CD15, CD43, CD45, CD68, MAC-386, HAM56, and lysozyme, which is consistent with a monocytic-histiocytic immunoprofile. However, intense myeloperoxidase reactivity was detected in most of the cells with histiocytic appearance, which raised the possibility of specific cutaneous involvement by myelogenous leukemia. Nevertheless, cytologic peripheral blood examinations, fluorescent in situ hybridization studies to investigate the bcr/abl gene fusion, and follow-up of the patients, taken all together, ruled out this possibility. CONCLUSIONS: This case series demonstrates that some fresh cutaneous lesions of Sweet syndrome are histopathologically characterized by an infiltrate mostly composed of cells that may be misinterpreted as histiocytes, when in fact they are immature myeloid cells. We named this histopathologic variant histiocytoid Sweet syndrome, which should not be mistaken with leukemia cutis or other inflammatory dermatoses that are histopathologically characterized by histiocytes interstitially arranged between collagen bundles of the dermis.
Histiocytoid Sweet syndrome: a dermal infiltration of immature neutrophilic granulocytes.
Berbamine: A novel inhibitor of bcr/abl fusion gene with potent anti-leukemia activity.
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Xu R, Dong Q, Yu Y, Zhao X, Gan X, Wu D, Lu Q, Xu X, Yu XF
Leuk Res. 2005 Jul 13;
Gleevec, which is an inhibitor of the bcr/abl tyrosine kinase, has been a remarkable success for the treatment of chronic myelogenous leukemia (CML). However, a significant proportion of patients chronically treated with Gleevec develop resistance. Here we describe the activity of a natural small molecular compound, berbamine from plant Berberis amurensis that can selectively induce cell death of both Gleevec-sensitive and -resistant Ph(+) CML cells. The IC(50) values of berbamine were 8.80mug/ml in Gleevec-sensitive Ph(+) CML cells, 11.34mug/ml in Gleevec-resistant Ph(+) CML cells, and 54.40mug/ml in Ph(-) KG-1 cells, respectively. Similarly, berbamine was also found to display a selective anti-proliferative activity of primary leukemia cells from CML patients, and its IC(50) values were 4.20-10.50mug/ml in primary CML cells, and 185.20mug/ml in normal bone marrow cells, respectively. More importantly, our studies demonstrate that berbamine down-regulates p210bcr/abl oncoprotein level, and induces apoptosis of bcr/abl+ cells through caspase-3-dependent pathway. These data suggest that berbamine might be a novel bcr/abl inhibitor with potent anti-leukemia activity.
Berbamine: A novel inhibitor of bcr/abl fusion gene with potent anti-leukemia activity.
BCR/ABL Promotes Dendritic Cell-Mediated Natural Killer Cell Activation.
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Terme M, Borg C, Guilhot F, Masurier C, Flament C, Wagner EF, Caillat-Zucman S, Bernheim A, Turhan AG, Caignard A, Zitvogel L
Cancer Res. 2005 Jul 15; 65(14): 6409-17
BCR/ABL fusion gene, encoding a paradigmatic tyrosine kinase involved in chronic myelogenous leukemia (CML), can modulate the expression of genes involved in natural killer (NK) cell target recognition. Recent reports outline the role of allogeneic antileukemic NK effectors in the graft-versus-leukemia effect but the regulation of NK cell activation in the setting of graft-versus-leukemia effect remains unknown. Here we show that dendritic cells derived from monocytes of CML patients are selectively endowed with NK cell stimulatory capacity in vitro. We further show, using a gene transfer approach in mouse bone marrow progenitors, that ABL/ABL is necessary to promote dendritic cell-mediated NK cell activation. The dendritic cell/NK cell cross-talk in ABL/ABL-induced CML seems unique because JunB or IFN consensus sequence binding protein loss of functions, associated with other myeloproliferative disorders, do not promote dendritic cell-mediated NK cell activation. NK cell activation by leukemic dendritic cells involves NKG2D activating receptors and is blocked by imatinib mesylate. Indeed, ABL/ABL translocation enhances the expression levels of the NKG2D ligands on dendritic cells, which is counteracted by imatinib mesylate. Altogether, the clonal ABL/ABL dendritic cells display the unique and selective ability to activate NK cells and may participate in the NK cell control of CML. This study also highlights the deleterious role of imatinib mesylate at the dendritic cell level for NK cell activation.
BCR/ABL Promotes Dendritic Cell-Mediated Natural Killer Cell Activation.
[An epidermal growth factor receptor-dependent e3B1/Abi1 protein as a tumor suppressing candidate in cancer]
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Jenei V, Jakus J
Orv Hetil. 2005 Jun 12; 146(24): 1293-9
Hungary is among the leading countries in Europe regarding the mortality and incidence of different types of tumours. Therefore, developing effective therapies is especially important in this country. Investigation of tumour formation and progression on the molecular level is required to develop possible therapeutical targets. Such targets can be proteins with tumour suppressor function, which inhibit intracellular signalling processes that under pathophysiological conditions can lead to uncontrolled cell proliferation and tumour formation. Protein e3B1/Abi-1, which belongs to the family of Abl-interactors, was isolated recently as a possible tumour suppressor. As a partner of Abl kinase, its role has been investigated in the development and progression of some types of leukemias, however, more and more experimental data suggest that it is a general suppressor protein. According to the latest results, e3B1/Abi-1 via the Ras small G-protein has an essential role in the regulation of cell proliferation, and via Rac activation it can affect actin remodelling, cell adhesion and migration. Cell proliferation is important in tumour development, while cell adhesion and migration has a role in metastasis formation. The latest results showed deletion of the gene encoding protein e3B1/Abi-1 in prostate cancer, loss of its expression during the progression of some types of leukemias, and there are data on the effect of imatinib mesylate (Gleevec or outside USA Glivec, Novartis), one of the newest drugs in leukemia treatment, on the phosphorylation of e3B1/Abi-1 as well. This report summarizes the data published on protein e3B1/Abi-1, with special interest in practical implications.