In embryogenesis, coronary blood vessels are formed by vasculogenesis from epicardium-derived progenitors. Subsequently, growing or regenerating myocardium increases its vasculature by angiogenesis, ...forming new vessels from the pre-existing ones. Recently, cell therapies for myocardium ischemia that used different protocols have given promising results, using either extra-cardiac blood vessel cell progenitors or stimulating the cardiac angiogenesis. We have questioned whether cardiomyocytes could sustain both vasculogenesis and angiogenesis. We used a 3D culture model of tissue-like spheroids in co-cultures of cardiomyocytes supplemented either with endothelial cells or with bone marrow-derived mesenchymal stroma cells. Murine foetal cardiomyocytes introduced into non-adherent U-wells formed 3D contractile structures. They were coupled by gap junctions. Cardiomyocytes segregated inside the 3D structure into clumps separated by connective tissue septa, rich in fibronectin. Three vascular endothelial growth factor isoforms were produced (VEGF 120, 164 and 188). When co-cultured with human umbilical cord endothelial cells, vascular structures were produced in fibronectin-rich external layer and in radial septa, followed by angiogenic sprouting into the cardiomyocyte microtissue. Presence of vascular structures led to the maintenance of long-term survival and contractile capacity of cardiac microtissues. Conversely, bone marrow mesenchymal cells formed isolated cell aggregates, which progressively expressed the endothelial markers von Willebrand's antigen and CD31. They proceeded to typical vasculogenesis forming new blood vessels organised in radial pattern. Our results indicate that the in vitro 3D model of cardiomyocyte spheroids provides the two basic elements for formation of new blood vessels: fibronectin and VEGF. Within the myocardial environment, endothelial and mesenchymal cells can proceed to formation of new blood vessels either through angiogenesis or vasculogenesis, respectively.
Mixed phenotype acute leukemia (MPAL) is considered as a rare type of leukemia with an incidence of less than 4% of all acute leukemia based on the most recent 2008 WHO classification. Common ...subtypes are the B/myeloid and T/myeloid; B/T and trilineage MPAL being extremely rare. We present a case of a male in his 20s, whose peripheral blood smears showed 34% blast cells and bone marrow with 70% blasts. Immunophenotyping by multiparametric flow cytometry showed two populations of blasts, the major one with B-lineage and the minor one with T-lineage. Conventional karyotyping revealed complex karyotype with the presence of double Philadelphia chromosome (Ph+). BCR/ABL1 rearrangement was confirmed by fluorescent in situ hybridization (FISH) analysis. The BCR/ABL1 ES probe on interphase cells indicated pl90 minor m-BCR/ABL fusion in 46% and a second abnormal clone with double Ph+ in 16% of the cells analyzed confirmed by reverse transcription-PCR (RT-PCR). The case was diagnosed as MPAL with double Philadelphia chromosome Ph+. The patient was treated with dasatinib, four cycle hyper CVAD/methotrexate cytarabin protocol, and allogeneic transplant. He is still alive in complete hematological, cytogenetic, and molecular remission. Mixed phenotype B/T acute leukemia is an extremely rare disease, particularly those with double Philadelphia chromosomes and clinically presents challenges in diagnosis and treatment.
Aggressive natural killer cell leukemia is an extraordinary rare aggressive malignant neoplasm of natural killer cells. Although its first recognition as a specific entity was approximately 20 years ...ago, this leukemia has not yet been satisfactorily characterized as fewer than 200 cases have been reported in the literature and up to our knowledge, this is the first case report in Qatar. Reaching a diagnosis of aggressive natural killer leukemia was a challenging experience, because in addition to being a rare entity, the relative scarcity of circulating neoplastic cells, failure to obtain an adequate aspirate sample sufficient to perform flow cytometric analysis, together with the absence of applicable method to prove NK clonality (as it lack specific clonal marker); our case had atypical confusing presentation of striking increase in bone marrow fibrosis that was misleading and complicated the case further. The bone marrow fibrosis encountered may be related to the neoplastic natural killer cells’ chemokine profile and it may raise the awareness for considering aggressive natural killer leukemia within the differential diagnosis of leukemia with heightened marrow fibrosis.
Abstract Objectives To evaluate the expression of different matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in vulvar lichen sclerosus (LS), a chronic dermatosis ...in women, histologically characterized by a zone of collagen remodeling in the superior dermis. Study design Analysis of the expression of different MMPs (MMP-1, -2, -9 and -13) and TIMPs (TIMP-1 and -2) by reverse transcriptase-polymerase chain reaction (RT-PCR) in vulvar biopsies from patients with LS ( n = 11), classified according to Hewitt histological criteria and compared with clinically normal vulvar tissue ( n = 5), and the immunohistochemistry of MMP-2 and -9 and TIMP-1 and -2 distribution in the remodeling zone of LS ( n = 31) and in clinically normal vulvar tissue ( n = 28). Results Although no statistically significant difference between LS and normal skin groups at the mRNA level of MMP and TIMP transcripts was shown, an increase in the immunodistribution of MMP-2 and -9 and TIMP-1 and -2 in LS compared to normal vulvar skin was observed. Conclusions These results suggest that these molecules could be related to the process of cutaneous collagen remodeling in LS pathology.
Serial assays of qualitative (multiplex and nested) and quantitative PCR were carried out for detecting and estimating the level of BCR-ABL transcripts in 39 CML patients following bone marrow ...transplantation. Seven of these patients, who received donor lymphocyte infusions (DLIs) following to relapse, were also monitored. Quantitative estimates of BCR-ABL transcripts were obtained by co-amplification with a competitor sequence. Estimates of ABL transcripts were used, an internal control and the ratio BCR-ABL/ABL was thus estimated for evaluating the kinetics of residual clones. Twenty four patients were followed shortly after BMT; two of these patients were in cytogenetic relapse coexisting with very high BCR-ABL levels while other 22 were in clinical, haematologic and cytogenetic remission 2–42 months after BMT. In this latter group, seven patients showed a favourable clinical-haematological progression in association with molecular remission while in 14 patients quantitative PCR assays indicated molecular relapse that was not associated with an early cytogenetic–haematologic relapse. BCR-ABL/ABL levels could not be correlated with presence of GVHD in 24 patients after BMT. In all seven patients treated with DLI, high levels of transcripts were detected at least 4 months before the appearance of clinical haematological relapse. Following DLI, five of these patients showed decreasing transcript levels from 2 to 5 logs between 4 and 12 months. In eight other patients studied long after BMT, five showed molecular relapse up to 117 months post-BMT and only one showed cytogenetic relapse. Our findings indicated that quantitative estimates of BCR-ABL transcripts were valuable for monitoring minimal residual disease in each patient.
Philadelphia positive (Ph+) acute myeloid leukemia (AML) is a rare and heterogeneous condition, mainly reported in adults, associated to poor prognosis and unfavorable response to therapy. Here we ...report clinical and laboratory findings in an 8-year-old patient diagnosed with Ph+ acute leukemia with myeloid (FAB M4) morphology. The patient consistently expressed variable levels of m-bcr, e1a2 transcripts during a 42-month follow-up after two different stem cell transplantation protocols. An immunophenotypic switch was documented, from a mixed, myeloid-lymphoid lineage to a full lymphoid phenotype following stem cell transplants, in association with an immature B-cell gene rearrangement profile and clonal instability during clinical progression. This report indicates a stem cell origin as previously suggested for Ph+ AML.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
We have identified a rare BCR-ABL chimaeric gene with multiplex and nested RT-PCR in a patient with an unusually aggressive chronic myeloid leukaemia. cDNA sequencing showed an in-frame rearrangement ...with a breakpoint in BCR exon e13 (b2) and fusion with ABL exon 3 following skipping of the entire ABL exon a2. These data confirm the heterogeneity of breakpoints in BCR-ABL rearrangements.
Proechimys roberti has been considered an isolate representative of the guyannensis group of species of the genus Proechimys in the Cerrado of central Brazil, or regarded as a member of the ...longicaudatus group of species. We present new karyologic, morphometric, morphologic, and molecular data from populations spanning the gap between the previously known isolated distribution of P. roberti and the core distribution of the guyannensis group. All specimens had the same basic karyotype, 2n = 30, with fundamental number (FN) = 54-55. FN variation was due to a pericentric inversion affecting a small autosomal pair. Specimens from the eastern Amazon Basin and the Cerrado did not have any differentiation in external, cranial, and dental characters. In contrast, samples showed a significant multivariate morphometric variation, with a high heterogeneity among all populations, independent of Cerrado or Amazon location. Our results, coupled with phylogenetic analysis of cytochrome-b sequences, indicate that P. roberti is a valid species of the guyannensis group and that the species of this group occurring in eastern Amazon, P. oris, is probably a junior synonym of P. roberti.
Polymerase chain reaction (PCR) is a powerful and rapid method for specifically detecting
BCR–ABL rearrangement by amplification of the complementary DNA (cDNA) produced by reverse transcription of ...BCR–ABL mRNA. We studied 29 patients for detecting the presence of BCR-ABL transcripts before and after bone marrow transplantation (BMT). Our sample was composed of two different groups of patients: one group (
n=18) was studied by serial follow-ups before and after BMT; a second group (
n=11) was studied several years after BMT. Detection of
BCR–ABL was carried out with different primer sets at different periods of the clinical outcome of chronic myeloid leukaemia (CML). A comparison of PCR data and clinical–haematological conditions showed clear differences between patients. In the first group, eight patients showed a positive correlation between a favourable clinical outcome and molecular remission. Conversely, in the second group, six patients were
BCR–ABL positive between 20 and 117 months after BMT, while only two of these patients showed signs of clinical relapse. Among all patients whose isoforms were known at some time during the course of CML, the more frequent isoform was b3a2. These results were compared to previous findings in the literature on diagnosis, outcome and prognosis of CML.
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