Primary effusion lymphoma associated with Human Herpes Virus-8 and Epstein Barr virus in an HIV-infected woman from Kampala, Uganda: a case report

<p>Abstract</p> <p>Introduction</p> <p>Primary effusion lymphoma is a recently recognized entity of AIDS related non-Hodgkin lymphomas. Despite Africa being greatly affected by the HIV/AIDS pandemic, an extensive MEDLINE/PubMed search failed to find any report of primary effusion lymphoma in sub-Saharan Africa. To our knowledge this is the first report of primary effusion lymphoma in sub-Saharan Africa. We report the clinical, cytomorphologic and immunohistochemical findings of a patient with primary effusion lymphoma.</p> <p>Case presentation</p> <p>A 70-year-old newly diagnosed HIV-positive Ugandan African woman presented with a three-month history of cough, fever, weight loss and drenching night sweats. Three weeks prior to admission she developed right sided chest pain and difficulty in breathing. On examination she had bilateral pleural effusions.</p> <p>Haematoxylin and eosin stained cytologic sections of the formalin-fixed paraffin-embedded cell block made from the pleural fluid were processed in the Department of Pathology, Makerere University, College of Health Sciences, Kampala, Uganda. Immunohistochemistry was done at the Institute of Haematology and Oncology "L and A Seragnoli", Bologna University School of Medicine, Bologna, Italy, using alkaline phosphatase anti-alkaline phosphatase method. <it>In situ </it>hybridization was used for detection of Epstein-Barr virus.</p> <p>The tumor cells were CD45+, CD30+, CD38+, HHV-8 LANA-1+; but were negative for CD3-, CD20-, CD19-, and CD79a- and EBV RNA+ on <it>in situ </it>hybridization. CD138 and Ki-67 were not evaluable. Our patient tested HIV positive and her CD4 cell count was 127/μL.</p> <p>Conclusions</p> <p>A definitive diagnosis of primary effusion lymphoma rests on finding a proliferation of large immunoblastic, plasmacytoid and anaplastic cells; HHV-8 in the tumor cells, an immunophenotype that is CD45+, pan B-cell marker negative and lymphocyte activated marker positive. It is essential for clinicians and pathologists to have a high index of suspicion of primary effusion lymphoma when handling HIV positive patients who have effusions without palpable tumor masses. Basic immunohistochemistry is essential for definitive diagnosis.</p

Localization and density of phoretic deutonymphs of the mite Uropoda orbicularis (Parasitiformes : Mesostigmata) on Aphodius beetles (Aphodiidae) affect pedicel length

The phoretic stage of Uropodina mites is a deutonymph with developed morphological adaptations for dispersal by insects. Phoretic deutonymphs are able to produce a pedicel, a stalk-like temporary attachment structure that connects the mite with the carrier. The aim of our study was to determine whether localization and density of phoretic deutonymphs on the carrier affect pedicel length. The study was conducted on a common phoretic mite-Uropoda orbicularis (Uropodina) and two aphodiid beetles-Aphodius prodromus and Aphodius distinctus. Our results show that pedicel length is influenced by the localization of deutonymphs on the body of the carrier. The longest pedicels are produced by deutonymphs attached to the upper part of elytra, whereas deutonymphs attached to femora and trochanters of the third pair of legs and the apex of elytra construct the shortest pedicels. In general, deutonymphs attached to more exposed parts of the carrier produce longer pedicels, whereas shorter pedicels are produced when deutonymphs are fixed to non-exposed parts of the carrier. A second factor influencing pedicel length is the density of attached deutonymphs. Mean pedicel length and deutonymph densities were highly correlated: higher deutonymph density leads to the formation of longer pedicels. The cause for this correlation is discussed, and we conclude that pedicel length variability can increase successful dispersal

Reaction rates and transport in neutron stars

Understanding signals from neutron stars requires knowledge about the transport inside the star. We review the transport properties and the underlying reaction rates of dense hadronic and quark matter in the crust and the core of neutron stars and point out open problems and future directions.Comment: 74 pages; commissioned for the book "Physics and Astrophysics of Neutron Stars", NewCompStar COST Action MP1304; version 3: minor changes, references updated, overview graphic added in the introduction, improvements in Sec IV.A.

Search for CP violation in D+→ϕπ+ and D+s→K0Sπ+ decays

A search for CP violation in D + → ϕπ + decays is performed using data collected in 2011 by the LHCb experiment corresponding to an integrated luminosity of 1.0 fb−1 at a centre of mass energy of 7 TeV. The CP -violating asymmetry is measured to be (−0.04 ± 0.14 ± 0.14)% for candidates with K − K + mass within 20 MeV/c 2 of the ϕ meson mass. A search for a CP -violating asymmetry that varies across the ϕ mass region of the D + → K − K + π + Dalitz plot is also performed, and no evidence for CP violation is found. In addition, the CP asymmetry in the D+s→K0Sπ+ decay is measured to be (0.61 ± 0.83 ± 0.14)%

Improved blood tests for cancer screening: general or specific?

Diagnosis of cancer at an early stage leads to improved survival. However, most current blood tests detect single biomarkers that are of limited suitability for screening, and existing screening programmes look only for cancers of one particular type. A new approach is needed. Recent developments suggest the possibility of blood-based screening for multiple tumour types. It may be feasible to develop a high-sensitivity general screen for cancer using multiple proteins and nucleic acids present in the blood of cancer patients, based on the biological characteristics of cancer. Positive samples in the general screen would be submitted automatically for secondary screening using tests to help define the likelihood of cancer and provide some indication of its type. Only those at high risk would be referred for further clinical assessment to permit early treatment and mitigate potential overdiagnosis. While the assays required for each step exist, they have not been used in this way. Recent experience of screening for breast, cervical and ovarian cancers suggest that there is likely to be widespread acceptance of such a strategy

Characterization of 4-HNE Modified L-FABP Reveals Alterations in Structural and Functional Dynamics

4-Hydroxynonenal (4-HNE) is a reactive α,β-unsaturated aldehyde produced during oxidative stress and subsequent lipid peroxidation of polyunsaturated fatty acids. The reactivity of 4-HNE towards DNA and nucleophilic amino acids has been well established. In this report, using proteomic approaches, liver fatty acid-binding protein (L-FABP) is identified as a target for modification by 4-HNE. This lipid binding protein mediates the uptake and trafficking of hydrophobic ligands throughout cellular compartments. Ethanol caused a significant decrease in L-FABP protein (P<0.001) and mRNA (P<0.05), as well as increased poly-ubiquitinated L-FABP (P<0.001). Sites of 4-HNE adduction on mouse recombinant L-FABP were mapped using MALDI-TOF/TOF mass spectrometry on apo (Lys57 and Cys69) and holo (Lys6, Lys31, His43, Lys46, Lys57 and Cys69) L-FABP. The impact of 4-HNE adduction was found to occur in a concentration-dependent manner; affinity for the fluorescent ligand, anilinonaphthalene-8-sulfonic acid, was reduced from 0.347 µM to Kd1 = 0.395 µM and Kd2 = 34.20 µM. Saturation analyses revealed that capacity for ligand is reduced by approximately 50% when adducted by 4-HNE. Thermal stability curves of apo L-FABP was also found to be significantly affected by 4-HNE adduction (ΔTm = 5.44°C, P<0.01). Computational-based molecular modeling simulations of adducted protein revealed minor conformational changes in global protein structure of apo and holo L-FABP while more apparent differences were observed within the internal binding pocket, revealing reduced area and structural integrity. New solvent accessible portals on the periphery of the protein were observed following 4-HNE modification in both the apo and holo state, suggesting an adaptive response to carbonylation. The results from this study detail the dynamic process associated with L-FABP modification by 4-HNE and provide insight as to how alterations in structural integrity and ligand binding may a contributing factor in the pathogenesis of ALD

Murine Gamma-herpesvirus Immortalization of Fetal Liver-Derived B Cells Requires both the Viral Cyclin D Homolog and Latency-Associated Nuclear Antigen

Human gammaherpesviruses are associated with the development of lymphoproliferative diseases and B cell lymphomas, particularly in immunosuppressed hosts. Understanding the molecular mechanisms by which human gammaherpesviruses cause disease is hampered by the lack of convenient small animal models to study them. However, infection of laboratory strains of mice with the rodent virus murine gammaherpesvirus 68 (MHV68) has been useful in gaining insights into how gammaherpesviruses contribute to the genesis and progression of lymphoproliferative lesions. In this report we make the novel observation that MHV68 infection of murine day 15 fetal liver cells results in their immortalization and differentiation into B plasmablasts that can be propagated indefinitely in vitro, and can establish metastasizing lymphomas in mice lacking normal immune competence. The phenotype of the MHV68 immortalized B cell lines is similar to that observed in lymphomas caused by KSHV and resembles the favored phenotype observed during MHV68 infection in vivo. All established cell lines maintained the MHV68 genome, with limited viral gene expression and little or no detectable virus production - although virus reactivation could be induced upon crosslinking surface Ig. Notably, transcription of the genes encoding the MHV68 viral cyclin D homolog (v-cyclin) and the homolog of the KSHV latency-associated nuclear antigen (LANA), both of which are conserved among characterized γ2-herpesviruses, could consistently be detected in the established B cell lines. Furthermore, we show that the v-cyclin and LANA homologs are required for MHV68 immortalization of murine B cells. In contrast the M2 gene, which is unique to MHV68 and plays a role in latency and virus reactivation in vivo, was dispensable for B cell immortalization. This new model of gammaherpesvirus-driven B cell immortalization and differentiation in a small animal model establishes an experimental system for detailed investigation of the role of gammaherpesvirus gene products and host responses in the genesis and progression of gammaherpesvirus-associated lymphomas, and presents a convenient system to evaluate therapeutic modalities

A Computational Profiling of Changes in Gene Expression and Transcription Factors Induced by vFLIP K13 in Primary Effusion Lymphoma

Infection with Kaposi's sarcoma associated herpesvirus (KSHV) has been linked to the development of primary effusion lymphoma (PEL), a rare lymphoproliferative disorder that is characterized by loss of expression of most B cell markers and effusions in the body cavities. This unique clinical presentation of PEL has been attributed to their distinctive plasmablastic gene expression profile that shows overexpression of genes involved in inflammation, adhesion and invasion. KSHV-encoded latent protein vFLIP K13 has been previously shown to promote the survival and proliferation of PEL cells. In this study, we employed gene array analysis to characterize the effect of K13 on global gene expression in PEL-derived BCBL1 cells, which express negligible K13 endogenously. We demonstrate that K13 upregulates the expression of a number of NF-κB responsive genes involved in cytokine signaling, cell death, adhesion, inflammation and immune response, including two NF-κB subunits involved in the alternate NF-κB pathway, RELB and NFKB2. In contrast, CD19, a B cell marker, was one of the genes downregulated by K13. A comparison with K13-induced genes in human vascular endothelial cells revealed that although there was a considerable overlap among the genes induced by K13 in the two cell types, chemokines genes were preferentially induced in HUVEC with few exceptions, such as RANTES/CCL5, which was induced in both cell types. Functional studies confirmed that K13 activated the RANTES/CCL5 promoter through the NF-κB pathway. Taken collectively, our results suggest that K13 may contribute to the unique gene expression profile, immunophenotype and clinical presentation that are characteristics of KSHV-associated PEL

Epstein-Barr Virus LMP2A Reduces Hyperactivation Induced by LMP1 to Restore Normal B Cell Phenotype in Transgenic Mice

Epstein-Barr virus (EBV) latently infects most of the human population and is strongly associated with lymphoproliferative disorders. EBV encodes several latency proteins affecting B cell proliferation and survival, including latent membrane protein 2A (LMP2A) and the EBV oncoprotein LMP1. LMP1 and LMP2A signaling mimics CD40 and BCR signaling, respectively, and has been proposed to alter B cell functions including the ability of latently-infected B cells to access and transit the germinal center. In addition, several studies suggested a role for LMP2A modulation of LMP1 signaling in cell lines by alteration of TRAFs, signaling molecules used by LMP1. In this study, we investigated whether LMP1 and LMP2A co-expression in a transgenic mouse model alters B cell maturation and the response to antigen, and whether LMP2A modulates LMP1 function. Naïve LMP1/2A mice had similar lymphocyte populations and antibody production by flow cytometry and ELISA compared to controls. In the response to antigen, LMP2A expression in LMP1/2A animals rescued the impairment in germinal center generation promoted by LMP1. LMP1/2A animals produced high-affinity, class-switched antibody and plasma cells at levels similar to controls. In vitro, LMP1 upregulated activation markers and promoted B cell hyperproliferation, and co-expression of LMP2A restored a wild-type phenotype. By RT-PCR and immunoblot, LMP1 B cells demonstrated TRAF2 levels four-fold higher than non-transgenic controls, and co-expression of LMP2A restored TRAF2 levels to wild-type levels. No difference in TRAF3 levels was detected. While modulation of other TRAF family members remains to be assessed, normalization of the LMP1-induced B cell phenotype through LMP2A modulation of TRAF2 may be a pathway by which LMP2A controls B cell function. These findings identify an advance in the understanding of how Epstein-Barr virus can access the germinal center in vivo, a site critical for both the genesis of immunological memory and of virus-associated tumors

Characterizing low affinity epibatidine binding to α4β2 nicotinic acetylcholine receptors with ligand depletion and nonspecific binding

<p>Abstract</p> <p>Background</p> <p>Along with high affinity binding of epibatidine (<it>K</it>_d1≈10 pM) to α4β2 nicotinic acetylcholine receptor (nAChR), low affinity binding of epibatidine (<it>K</it>_d2≈1-10 nM) to an independent binding site has been reported. Studying this low affinity binding is important because it might contribute understanding about the structure and synthesis of α4β2 nAChR. The binding behavior of epibatidine and α4β2 AChR raises a question about interpreting binding data from two independent sites with ligand depletion and nonspecific binding, both of which can affect equilibrium binding of [³H]epibatidine and α4β2 nAChR. If modeled incorrectly, ligand depletion and nonspecific binding lead to inaccurate estimates of binding constants. Fitting total equilibrium binding as a function of total ligand accurately characterizes a single site with ligand depletion and nonspecific binding. The goal of this study was to determine whether this approach is sufficient with two independent high and low affinity sites.</p> <p>Results</p> <p>Computer simulations of binding revealed complexities beyond fitting total binding for characterizing the second, low affinity site of α4β2 nAChR. First, distinguishing low-affinity specific binding from nonspecific binding was a potential problem with saturation data. Varying the maximum concentration of [³H]epibatidine, simultaneously fitting independently measured nonspecific binding, and varying α4β2 nAChR concentration were effective remedies. Second, ligand depletion helped identify the low affinity site when nonspecific binding was significant in saturation or competition data, contrary to a common belief that ligand depletion always is detrimental. Third, measuring nonspecific binding without α4β2 nAChR distinguished better between nonspecific binding and low-affinity specific binding under some circumstances of competitive binding than did presuming nonspecific binding to be residual [³H]epibatidine binding after adding a large concentration of cold competitor. Fourth, nonspecific binding of a heterologous competitor changed estimates of high and low inhibition constants but did not change the ratio of those estimates.</p> <p>Conclusions</p> <p>Investigating the low affinity site of α4β2 nAChR with equilibrium binding when ligand depletion and nonspecific binding are present likely needs special attention to experimental design and data interpretation beyond fitting total binding data. Manipulation of maximum ligand and receptor concentrations and intentionally increasing ligand depletion are potentially helpful approaches.</p