bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comprehensive Biomarker and Genomic Analysis Identifies p53 Status as the Major Determinant of Response to MDM2 Inhibitors in Chronic Lymphocytic Leukemia.
Authors: Malek Sami N. , Ouillette Peter , Kujawski Lisa , Shangary Sanjeev , Talpaz Moshe , Kaminski Mark , Erba Harry , Shedden Kerby , Wang Shaomeng , Saddler Chris 
Published: April 2020

Abstract
To understand determinants of sensitivity or resistance to MDM2 inhibitor therapy in chronic lymphocytic leukemia (CLL), we comprehensively analyzed highly pure CD19+ cells derived from 106 CLL patients for response to the MDM2 inhibitors MI-63 and Nutlin3 ex vivo and correlated these responses with clinically important biomarkers, including hierarchical FISH, IgVH-mutations and ZAP70 expression. P53 exons 5–9 were sequenced for all cases, and p53 induction pre- and post-inhibitor treatment was determined by immunoblotting for all 106 samples. Furthermore, we employed high-density 50kSNP-arrays to analyze changes of copy number and allele status, including that of p53 on chromosome 17p, in 171 CLL patients and correlated this finding with p53 mutations and p53 expression. Patient-derived samples were incubated for 36 hours with both inhibitors in parallel and apoptotic (annexin-V) and necrotic cell death (PI) was assayed for all incubations using flow cytometry. IC50 values were calculated using XL-fit. Nineteen CLL cases demonstrated either p53 mutations or aberrant expression and all were relatively resistant to MDM2 inhibitor treatment; eighty-seven cases had functional p53 and all but 3 cases demonstrated sensitivity to MDM2 inhibitor treatment. Very few cases with functional p53 demonstrated IC50 values for both inhibitors that were within the range of p53 mutant cases. Del17p patient samples were resistant to MDM2 inhibitor-mediated cell kill, while all other CLL biomarker-based subgroups appeared equally sensitive. Univariate time to first therapy (TTFT) estimates demonstrated a statistically significant (p=0.02 using the log-rank test) shorter TTFT for the group of 19 CLL cases with aberrant p53 function as opposed to the group of 87 cases with functional p53. Importantly, TTFT analysis for the 87 patients with functional p53 found that patients with low IC50 values (high sensitivity to MDM2 inhibitors) had more aggressive CLL (shorter TTFT), identifying for the first time a susceptible target group for these inhibitors that demonstrates aggressive disease and wt p53. In conclusion, the results of these studies conclusively demonstrate that p53 status is the major determinant of response to MDM2 inhibitors in CLL. Additional defects in the p53 regulatory cascade do not appear operational in this leukemia. This comprehensive dataset provides supportive rationale for the design of early phase human trials using these compounds and supports ex vivo measurements of p53 induction pre- and post-MDM2 inhibitor treatment as part of future trial schemas.
Measurement of Disease Severity in Patients with Sickle Cell Disease: A Systematic Review.
Authors: van den Tweel Xandra W. , van der Lee Johanna H. , Howard Jo , Fijnvandraat Karin ,   (Intr. by Marinus H.J. Van Oers )
Published: April 2020

Abstract
Background: The clinical picture in sickle cell disease (SCD) is highly heterogeneous. Knowledge of the determinants of a severe disease course will help us to unravel the pathophysiological mechanisms underlying the disease process and provide novel targets for therapeutic interventions. To generate this knowledge well designed etiological studies are needed, using a valid outcome measure for disease severity.
Objective: The aim of this systematic review is to identify all indices used to discriminate SCD patients by their current disease severity and to evaluate the methodological foundations of the indices and utility for clinical research.
Method: We performed a systematic search in MEDLINE (Pubmed) (1966- February 2006) using the search terms: anaemia, sickle cell/ [MeSH]; health status indicators/ [MeSH]; severity; severe and clinical spectrum. Reference lists of relevant studies and reviews were screened to identify additional articles. Information was extracted in duplicate by two independent reviewers (XT, KF).
Results: The Medline search yielded 1346 abstracts from which we selected 91 articles. Reference tracking resulted in 20 additional articles. After evaluation of the full text of these 111 articles, 28 articles (27 in English) were included in the review. These 28 indices contained 50 different items, including age at diagnosis, symptoms, findings at physical examination, laboratory values, organ damage, treatments and socio-economic consequences. The five most frequently used items were painful vaso-occlusive crises (86% of the indices), central nervous system abnormalities (59%), aseptic/avascular necrosis of the bone (52% of the indices), acute chest syndrome (48% of the indices) and leg ulcers (48% of the indices). Many indices (37%) were calculated by adding up scores on individual items without making a difference in the weight of the constituent items. In indices that did differentiate between items by allocating scores differentially, the rationale for weighing of the items was not explained. There were no scores that clearly distinguished devastating complications from complications that leave no sequelae. Most severity indices (89%) were not validated.
Conclusion: In order to increase our understanding of the pathofysiology of SCD and identify potential targets for new therapeutic interventions, we need to identify the determinants of a severe phenotype. For this purpose, consensus on the concept of severity in SCD and an instrument or index to measure it are necessary. This review reveals that there is no consensus on a definition of SCD severity and an index to measure it. Given the current state, efforts should be made to reach international consensus on a definition of SCD severity and a core set of items to measure this concept should be developed.
Low Socioeconomic Status, Not Silent Cerebral Infarcts, Is Associated with Grade Failure in Children with Sickle Cell Anemia.
Authors: King Allison A. ,   the Silent Infarct Transfusion Trial Investigators
Published: April 2020

Abstract
Background: Among students with sickle cell anemia (SCA), cerebral infarcts are an established risk factor for poor cognition and academic achievement. We tested the hypothesis that in children with SCA, lower socioeconomic status (SES) is associated with grade failure.
Methods: We evaluated the association between the SES as measured by annual income per person in household per year, age of student, gender, medical history and grade failure in children with SCA in 24 sites participating in the Silent Cerebral Infarct Multi-Center Clinical Trial.
Results: A total of 404 students were evaluable. The mean age was 9.2 years (range 6–13), 37% had a silent infarct, 15% failed a grade, and 18% had an Individualized Education Plan. SES was divided in tertiles based on annual income/person in the household/year &lt; $5000, $5000–$9999, &gt; $10,000. After adjustment for covariates, the risk of grade failure was 1.4 (95% CI 1.2, 1.6) for each increasing year of age, and 1.9 (95% CI 1.03, 3.5) for male gender. Children from households of the lowest tertile were 4 times more likely to fail a grade than children from the top tertile. A silent cerebral infarct was not associated with grade failure 1.4 (95% CI 0.8, 2.6). No student with a history of grade failure was hospitalized &gt; 3 times per year over the past three years.
Conclusion: Among students with SCA, poverty is the greatest risk factor for grade failure; whereas the presence of silent cerebral infarct is not. Targeted strategies to improve educational attainment in students with SCA are needed.
Heat Shock Protein Inhibition in Sickle Cell Disease: A Novel Approach to Attenuating the Inflammatory Response?.
Authors: Natarajan Kavita , Catravas John , Cannon Joseph , Li Tao , Kutlar Ferdane , Sloan Gloria , Fields Sabine , Clair Betsy , Kutlar Abdullah 
Published: April 2020

Abstract
Sickle cell disease (SCD) is a genetic disorder resulting from a single amino acid substitution on the β globin chain. It is well established that inflammation is a key component of the protean manifestations and complications of SCD. The heat shock proteins are a group of evolutionarily conserved proteins that are up-regulated in response to cellular stress. However, it has been recognized that an exaggerated response may be detrimental rather than beneficial. In our exploratory study, we look at effects of Hsp90 inhibition in mononuclear cells from controls and patients with SCD after stimulation with lipopolysaccharide (LPS). Whole blood was drawn from 2 African-American controls and 6 patients with SCD in steady state (3 on hydroxyurea (HU) and 3 off HU). Mononuclear cells were separated using Ficoll Hypaque density gradient centrifugation and were washed and suspended in RPMI containing penicillin, streptomycin, and heat inactivated autologous serum. Dilution of the final cell suspension was adjusted to achieve a mononuclear cell count of 400,000/0.5 ml. Each subject’s cell suspension was divided into 4 aliquots: control (V), cells stimulated with LPS (L), and cells treated with heat shock protein inhibitors 17-AAG (A) and Radiciol (R) followed by stimulation with LPS. Subsequently cell suspensions were incubated for 24 hours in a CO2 incubator at 37°C. Supernatants were then extracted and frozen at −70°C. Multiplex cytokine bead assay was performed. No significant change in response to LPS challenge or Hsp90 inhibition was observed for IFNγ, IL-2, IL-4, and IL-5. TNFα and IL-10 showed significant increases with LPS challenge, which could be almost completely inhibited by preincubation with 17-AAG and Radiciol. The magnitude of the TNFα and IL-10 responses to LPS challenge in SCD patients was significantly greater than controls. This held true for patients on and off HU. While there seemed to be a trend towards a more blunted response of TNFα to LPS challenge in HU treated patients, the numbers in this exploratory study are too small to allow statistical comparisons. These data confirm the previous observations that mononuclear cells in SCD are in an activated state and respond to LPS challenge in a more pronounced manner. The increase in IL-10 is more likely the result of a counteractive response to TNFα elevations. Significant observation of this preliminary study is that the inhibition of Hsp90 blunts the TNFα response to LPS challenge and may potentially offer a mechanism of modulation of inflammation in SCD. Determinations of other inflammatory cytokines are currently underway.
Figure Figure
Novel Findings Support a Patophysiological Role of the Arachidonic Cascade in Hodgkin Lymphoma.
Authors: Sjoberg Jan , Schain Frida , Tryselius Ylva , Backman Linda , Porwit Anna , Liu Cheng , Xu Dawei , Wei Wenbin , Baumforth Karl , Murray Paul , Bjorkholm Magnus , Claesson Hans-Erik 
Published: April 2020

Abstract
Lipoxygenases (LO) are a family of structurally related enzymes which catalyze the conversion of the fatty acid arachidonic acid to biologically active metabolites. The key enzyme in leukotriene synthesis, 5- LO, catalyzes the first step in the metabolism of arachidonic acid to leukotriene (LT) C4. This compound and its metabolites LTD4 and LTE4, collectively called cysteinyl leukotrienes (cysLT), can bind to two high-affinity receptors, named cysLT1 and cysLT2. A sister enzyme to 5-LO is 15-LO-1 which also can catalyze the formation of bioactive metabolites. Arachidonic acid metabolites have traditionally been linked to inflammation and asthma but several studies also indicate a role of these metabolites in carcinogenesis In our studies of arachidonic acid metabolism in human lymphomas, we have identified the expression of 15-LO-1 and receptors for cysLT in primary as well as cultured Hodgkin-Reed Sternberg (H-RS) cells. In tumor tissue, H-RS cells positive for 15-LO-1 and the cysLT1 receptor were detected immunohistochemically in 13/15 and 12/16 cases, respectively. The presence of mRNA for 15-LO-1 and the cysLT1 and 2 receptors was confirmed by microarray analysis of laser dissected H-RS cells. Studies of 15-LO-1 gene transcription revealed that STAT6 activation and chromatin remodeling by DNA demethylation and histone acetylation are crucial for transcriptional activation of this gene in cultured H-RS cells. Incubation of the Hodgkin lymphoma-derived cell lines KMH2 and L1236 with LTD4 led to a robust calcium response that was completely abolished in presence of the cysLT1 receptor inhibitor zafirlukast. In L1236 cells, LTD4 induced increased DNA synthesis, interleukin-13 transcription and release of TNF-alpha, interleukin-6 and interleukin-8 in a dose-dependent manner, all of which were inhibited by zafirlukast. Thus, as the H-RS cells lack the expression of 5-LO, we hypothesize that that tumor-associated cysLT-producing inflammatory cells, such as eosinophils and mast cells, contribute to the pathogenesis of Hodgkin lymphoma through induction of tumor cell proliferation and cytokine release. Furthermore, immunohistochemical studies of 20 non-Hodgkin lymphomas revealed the expression of cysLT1 receptors also in primary mediastinal B cell lymphomas (PMBCL), and the functionality of these receptors was confirmed in the PMBCL-derived cell line MedB1. Taken together, these novel findings support a role for arachidonic acid metabolites in the pathogenesis of lymphoma.
Photopheresis in HIV-1 Infected Patients Utilizing (Benzoporphyrin Derivative Verteporfin/BPD-MA) and Light.
Authors: Bernstein Zale P. , Dougherty Thomas , Gollnick Sandra , Schwartz Stanley , Mahajan Supriya , Kepner James , Sumlin Adam , Stewart Carleton , Wallace Paul , Walder Harold , Poiesz Bernard 
Published: April 2020

Abstract
An ex vivo trial utilizing photopheresis with Benzoporphyrin Derivative as the photoactive compound, identified the minimum energy levels of light and concentrations of BPD that eradicated both cell-free and cell-associated HIV-1 infectivity without destroying the virus particles or infected leukocytes. Leukocytes remained viable with altered chemokine/cytokine expression. Apoptosis was induced in a minority of CD4 but not CD8 positive cells with a statistically significant increase in cytolytic T-cell activity. In the 24 week clinical trial in seven HIV-1 infected patients. Three who had rapidly rising viral loads prior to initiating therapy stabilized. Two had a (sustained) greater than .5 log decrement and 5 had stable plasma viral loads (less than a .5 log increment or decrement) with varied effects on absolute CD4 and CD8 positive lymphocytes counts. One achieved a greater than 1 log decrement in HIV-1 plasma viral load and undetectable in vivo cell-free and cell-associated HIV-1 infectivity with an increased in vitro lymphocyte mitogen stimulation index. Under amended protocol 5 additional 12 month courses were administered to three additional patients and two of the previous enrollees. Area under the curve for viral load showed a significant decrease from pre to post therapy (p 0.007). No associated toxicities observed.
Long-Distance Tunneling Nanotubules Shuttle Viral Immunoglobulin Class Switch-Suppressing Factors from HIV-Infected Macrophages to B Cells.
Authors: Xu Weifeng , Santini Paul A. , Shan Meimei , Chen Kang , Ball Susan C. , Chiu April , Kingsley Lawrence A. , Rinaldo Charles R. , Chadburn Amy , Knowles Daniel M. , He Bing , Cerutti Andrea 
Published: April 2020

Abstract
Class switching from immunoglobulin M (IgM) to IgG, IgA or IgE is central to immunity against viruses and requires activation of B cells by CD4+ T cells through CD40 ligand (CD40L). Human immunodeficiency virus (HIV) evades protective T cell-dependent IgG and IgA responses against viral proteins and vaccines through mechanisms that remain unknown. Recent findings from our lab suggested the involvement of negative factor (Nef), an HIV accessory protein that suppresses CD40 signaling in B cells. The present work addressed the mechanism by which Nef invades B cells. Fluorescence microscopy-based studies showed that accumulation of Nef in infected lymphoid follicles was associated with severe loss of activation-induced cytidine deaminase (AID), a Nef-targeted DNA-editing enzyme essential for class switching. Loss of follicular AID correlated with in vivo inactivation of CD40 signaling and formation of long-distance membrane tethers connecting Nef-positive B cells with HIV-infected macrophages. By combining confocal microscopy, videomicroscopy and electron microscopy with standard molecular biology techniques, we demonstrated that macrophages harboring HIV or expressing a chimeric Nef-green-fluorescent protein were capable of transferring Nef-containing cargos to B cells via long-distance, actin-propelled and energy-dependent membrane channels, including tunneling nanotubules. Transfer of Nef to B cells involved a clathrin-dependent pathway that required the guanine nucleotide exchange factor Vav as well as downstream Rho, Rac and Ccd42 small GTPases. This pathway led to Nef-mediated inhibition of CD40-induced AID expression and IgG and IgA class switching. In summary, our findings indicate that HIV evades T cell-dependent IgG and IgA responses by shuttling virus-encoded Ig class switch-suppressing factors from infected macrophages to non-infected B cells via long-range membrane tethers, including tunneling nanotubules.
The Histone Acetyltransferase CBP Is Essential for Conventional T Cell Development.
Authors: Fukuyama Tomofusa , Boussouar Fayçal , Kasper Lawryn H. , van Deursen Jan M. , Brindle Paul K. 
Published: April 2020

Abstract
Defining the epigenetic mechanisms (e.g. chromatin modifications) that underlie T cell fate decisions is a major challenge. The transcriptional coactivators CREB binding protein (CBP) and the closely related p300 comprise a two-member family of histone/protein acetyltransferases that interact with over 50 T lymphocyte-essential transcriptional regulators. Rather than having distinct regulatory roles, CBP and p300 are often thought to confer utilitarian transactivation and histone modifying functions to transcription factors that mediate T cell fate. In contrast to this view, we show here that CBP acts uniquely in conventional T cell development. Inactivation of CBP, but not p300, starting at the double negative stage of T cell development yielded thymocytes with partial activation of an effector/memory- or innate-T cell program. CD8SP thymocytes from CBP mutant mice expressed genes that define professional CD8 cells such as Il-2/Il-15 receptor β chain, granzyme A, interferon γ (Ifnγ), Fas ligand, perforin, and the chemokine receptors Ccr5, and Cxcr3. CD4SP thymocytes from CBP mutant mice also expressed effector genes such as Ifnγ, Il-4, and Ccr5. In addition, CD8SP and CD4SP thymocytes from CBP mutant mice produced Ifnγ protein when the cells were stimulated with phorbol ester and ionomycin. Mechanistically, loss of CBP acted cell non-autonomously to induce the expression of the CD8 T cell master regulatory transcription factor eomesodermin (Eomes). This suggests that CBP in thymocytes or T cells controls an extracellular factor that helps demarcate conventional naïve T cell development in the thymus from effector/memory T cell differentiation in the periphery.
Novel Human CD4+ T Lymphocyte Subpopulations Defined by CD300a/c Molecule Expression.
Authors: Hart Derek N.J. , Rao Min , Ju Xinsheng , Clark Georgina J. 
Published: April 2020

Abstract
CD300a and CD300c are leukocyte membrane glycoproteins encoded by genes in the CD300 complex on human chromosome 17. These molecules function as immunoregulatory molecules that initiate triggering and inhibitory responses following ligation with ligands. The CMRF-35 monoclonal antibody binds to an epitope common to both molecules, expressed on most human leukocyte populations, apart from B lymphocytes and a subpopulation of CD4+ and CD8+ T lymphocytes. We used it to study the distribution of the CD300a and CD300c molecules on peripheral blood CD4+ T lymphocytes and defined novel CD300a/c++ , CD300a/c+ and CD300a/c− CD4+ T lymphocyte subpopulations. Resting peripheral CD4+ T lymphocytes express CD300a mRNA and very low amounts of CD300c. Activation results in an initial decrease in CD300a gene expression before an increase in both CD300a and CD300c gene expression. The upregulated expression of these genes was associated with increased CMRF-35 binding to activated T lymphocytes. The CD300a/c− fraction of CD4+ T lymphocytes proliferated to a greater extent than the CD300a/c++ fraction, in response to mitogens or allogeneic antigen. The poor proliferation of the CD300a/c++CD4+ in response to mitogens was explained by increased apoptosis within this subpopulation. The recall antigen, tetanus toxoid, stimulated the CD300a/c++CD4+CD45RO+ but not the CD300a/c−CD4+CD45RO+ subpopulation. Resting CD300a/c++CD4+ lymphocytes express low levels of IFNγ mRNA. Within 18 hours following in vitro activation, CD300a/c++CD4+ lymphocytes express more IFNγ mRNA and protein compared to the CD300a/c−CD4+ lymphocytes, however, after 24 hours both the CD300a/c+ and CD300a/c− CD4+ T lymphocytes were able to produce IFNγ. Th1 and Th17 effector populations are found within the CD300a/c++CD4+ T lymphocyte population, whilst the Treg population are restricted to the CD300a/c−CD4+ T lymphocyte population. Thus, CD300a/c subdivides CD4+ subpopulations into functional populations with the potential to immunoregulate immune and allogeneic responses. We are currently monitoring these populations in allogeneic haemopoietic stem cell recipients.