George Georgiou

CD138 Expression Helps Distinguishing Waldenström's Macroglobulinemia (WM) From Splenic Marginal Zone Lymphoma (SMZL)

The distinction between WM and SMZL may be difficult since both entities share overlapping clinical, immunophenotypic, and histopathologic characteristics. In this context we evaluated whether CD138 expression could be added in the armamentarium of tools used to differentiate these entities. Sixty-nine patients were studied, 47 WM and 22 SMZL. Paraffin-embedded sections of bone marrow biopsies were quantitatively and qualitatively evaluated for CD138 expression. Sixty percent of WM cases expressed CD138 in contrast to 18% of SMZL patients. Intermediate/high intensity of CD138 expression was observed in 47% of WM while it was low in all SMZL patients. Differences between WM and SMZL regarding the intensity and the percentage of CD138 positive cells were both significant (P=.0008 and, .00021 respectively). Moreover, CD138 expression was related to serum IgM levels in WM patients (P=.0006). In conclusion, CD138 expression may constitute an additional aid in the distinction between WM and SMZL.

All-loop anomalous dimensions in integrable λ-deformed σ-models

We calculate the all-loop anomalous dimensions of current operators in λ-deformed σ -models. For the isotropic integrable deformation and for a semi-simple group G we compute the anomalous dimensions using two different methods. In the first we use the all-loop effective action and in the second we employ perturbation theory along with the Callan–Symanzik equation and in conjunction with a duality-type symmetry shared by these models. Furthermore, using CFT techniques we compute the all-loop anomalous dimension of bilinear currents for the isotropic deformation case and a general G. Finally we work out the anomalous dimension matrix for the cases of anisotropic SU(2) and the two couplings, corresponding to the symmetric coset G/H and a subgroup H , splitting of a group G.

Isolated central nervous system relapses in primary mediastinal large B‐cell lymphoma after CHOP‐like chemotherapy with or without Rituximab

Central nervous system (CNS) involvement in patients with primary mediastinal large B‐cell (PMLBCL) lymphoma is a rare event, occurring in approximately 6% of patients, on the basis of the review of the literature prior to induction of Rituximab. The aim of this retrospective study was to describe the incidence of CNS relapse among 100 consecutive patients with PMLBCL who were treated with R‐CHOP ± RT in comparison to patients treated with CHOP ± RT (n = 45) in 11 hospitals in Greece. Two patients experienced a CNS relapse, representing an overall frequency of 2.0% in R‐CHOP treated patients and a 2‐year actuarial incidence of 2.3%. Both patients had isolated CNS relapses. The incidence of CNS relapse after CHOP without Rituximab was 2/45 (4.4%) for a 2‐year actuarial incidence of 7.5% (p = 0.29). Again, both patients had isolated CNS relapses. Parenchymal‐only localizations accounted for 3/4 cases. Risk factors for CNS involvement could include leukocytosis, poor performance status and higher age‐adjusted International Prognostic Index, although their impact was weakened by competing risk survival analysis. Both patients relapsing after R‐CHOP required CNS radiotherapy to achieve a complete remission and be forwarded to high‐dose therapy and autologous stem cell transplantation: They are both alive and disease‐free 18 and 23 months after CNS relapse. Both cases relapsing after CHOP without Rituximab were salvaged by CNS radiotherapy (one also received intrathecal chemotherapy) entering long‐term remissions. In conclusion, CNS relapses are rare in PMLBCL tending to be isolated in the CNS, probably reflecting the persistence of latent CNS disease than dissemination of resistant disease. The impact of Rituximab in reducing CNS relapses remains unknown. Established risk factors for CNS involvement in aggressive lymphomas may not be helpful in assessing the risk of CNS recurrence in this disease. Routine CNS prophylaxis is not probably required in PMLBCL. Copyright

All-loop correlators of integrable λ -deformed σ -models

We compute the 2- and 3-point functions of currents and primary fields of λ-deformed integrable σ -models characterized also by an integer k. Our results apply for any semisimple group G, for all values of the deformation parameter λ and up to order 1/k. We deduce the OPEs and equal-time commutators of all currents and primaries. We derive the currents’ Poisson brackets which assume Rajeev’s deformation of the canonical structure of the isotropic PCM, the underlying structure of the integrable λ-deformed σ -models. We also present analogous results in two limiting cases of special interest, namely for the non-Abelian T-dual of the PCM and for the pseudodual model.

Quantum aspects of doubly deformed CFTs

We study quantum aspects of the recently constructed doubly λ-deformed σ-models representing the effective action of two WZW models interacting via current bilinears. We show that although the exact beta-functions and current anomalous dimensions are identical to those of the λ-deformed models, this is not true for the anomalous dimensions of generic primary field operators in accordance with the fact that the two models differ drastically. Our proofs involve CFT arguments, as well as effective σ-model action and gravity calculations.

Double and cyclic λ-deformations and their canonical equivalents

We prove that the doubly λ-deformed σ-models, which include integrable cases, are canonically equivalent to the sum of two single λ-deformed models. This explains the equality of the exact β-functions and current anomalous dimensions of the doubly λ-deformed σ-models to those of two single λ-deformed models. Our proof is based upon agreement of their Hamiltonian densities and of their canonical structure. Subsequently, we show that it is possible to take a well defined non-Abelian type limit of the doubly-deformed action. Last, but not least, by extending the above, we construct multi-matrix integrable deformations of an arbitrary number of WZW models.

Overview of Myelodysplastic Syndromes

Myelodysplastic syndromes (MDS) were first presented as a separate entity in hematology in 1982 by the French-American-British (FAB) group. Although widely accepted, this classification was revised in 2001 and again in 2008 by the World Health Organization (WHO). During that time, a great effort was made by diagnostic entities of world renown as well as by other research groups and individuals to establish a reliable prognostic system. Today, two systems are accepted by the hematologic community: the International World Prognostic Scoring System (IPSS) and the WHO Prognostic Scoring System (WPSS). Almost from the beginning, it was assumed that MDS are clonal disorders. Cytogenetics not only proved the clonality in the majority of cases but also greatly contributed to the stratification of patients into risk categories. With the progress made in treatment for MDS, comorbidities became an important part of the integral pretreatment consideration, as patients with a high index of comorbidity evaluation very often do not benefit from treatment. Recent advances in the diagnostic and prognostic evaluation of MDS patients were achieved by studying the effect of age in different MDS subgroups and the role of molecular markers in predicting clinical evolution.

Traumatic Ulcerative Granuloma With Stromal Eosinophilia: Report of a Case and Literature Review

Traumatic eosinophilic granuloma with stromal eosinophilia is a rare entity that affects the oral mucosa and has a controversial etiologic pathogenesis. Histologically, these lesions are characterized by a dense and deeply infiltrative lymphoproliferation showing epitheliotropic characteristics and massive eosinophilia. Frequently, a population of mitotically active, atypical mononuclear cells can be noted. This report describes a case of traumatic eosinophilic granuloma with stromal eosinophilia in the floor of the mouth of an 88-year-old man. The phenotypic and genotypic profiles of the inflammatory infiltrate and large atypical mononuclear cells, using immunohistochemical and polymerase chain reaction-based molecular analysis, were analyzed.

The exact C-function in integrable λ-deformed theories

By employing CFT techniques, we show how to compute in the context of \lambda-deformations of current algebras and coset CFTs the exact in the deformation parameters C-function for a wide class of integrable theories that interpolate between a UV and an IR point. We explicitly consider RG flows for integrable deformations of left-right asymmetric current algebras and coset CFTs. In all cases, the derived exact C-functions obey all the properties asserted by Zamolodchikovs c-theorem in two-dimensions.

Genetic and molecular mechanisms in multiple myeloma: a route to better understand disease pathogenesis and heterogeneity

Multiple myeloma (MM) is a heterogeneous plasma cell neoplasm presenting with a wide range of clinical manifestations. In spite of the availability of very performing treatment modalities, survival is highly varying, ranging from a few months to several years. Underlying genetic and microenvironmental mechanisms are thought to be responsible for clinical heterogeneity. Disease etiology is unknown but progresses in the understanding of its pathogenesis have shown that MM precursor cell transformation into a malignant one occurs in a multistep process. Possibly during class switch recombination a primary genetic event takes place. With the occurrence of additional events and the support of bone marrow microenvironmental cells, neoplastic plasma cells actively proliferate and disease behavior may change. Recurrent translocations involving the IgH locus (11q13, 4p16, 16q23, 21q12, and 6p21), deletions of chromosome 13, trisomies of chromosomes 3, 5, 9, 11, 15, 19, and 21, and dysregulated expression of cyclin D genes, are considered initiating or primary events. Alterations related to further disease transformation and adverse prognosis are deletion of 17p13, c-myc translocations, and gains of chromosome 1q21. In relation to the underlying genetic defects, disease subgroups are recognized. Accordingly treatment effectiveness may differ among groups. Intense research is ongoing in this field.