Microscopic examination of bone marrow aspirates in malignant disorders of haematopoiesis—a comparison of two slide preparation techniques

It is mandatory to perform microscopic examinations of bone marrow aspirates during the diagnosis of many neoplastic haematopoiesis disorders. In 2008, The International Committee for Standardization in Hematology recommended the use of two types of slides for the microscopic evaluation of bone marrow: wedge-spread film and crush film slides. Because these techniques have not yet been compared, we performed such a comparison. Routine bone marrow samples from 250 patients diagnosed due to different neoplastic haematological disorders were evaluated. The major differences between the two compared techniques were identified in 13 patients with non-Hodgkin’s lymphoma, seven patients with systemic mastocytosis and 11 patients with acute leukaemias or myelodysplastic syndromes or chronic myelomonocytic leukaemia. Differences were noted also in many patients with multiple myeloma, but the clinical significance of these discrepancies was rather modest. The major causes of the differences observed seemed to be the dilution of marrow with blood cells and the focal growth of many neoplastic cells. We believe that the crush technique is more advantageous compared to the wedge-spread films. Therefore, we recommend the use of crush films as the primary method for establishing a diagnosis or for making therapeutic decisions based on the microscopic examination of bone marrow

A Comparative Approach Linking Molecular Dynamics of Altered Peptide Ligands and MHC with In Vivo Immune Responses

The recognition of peptide in the context of MHC by T lymphocytes is a critical step in the initiation of an adaptive immune response. However, the molecular nature of the interaction between peptide and MHC and how it influences T cell responsiveness is not fully understood.We analyzed the immunological consequences of the interaction of MHC class II (I-Au) restricted 11-mer peptides of myelin basic protein with amino acid substitutions at position 4. These mutant peptides differ in MHC binding affinity, CD4+ T cell priming, and alter the severity of peptide-induced experimental allergic encephalomyelitis. Using molecular dynamics, a computational method of quantifying intrinsic movements of proteins at high resolution, we investigated conformational changes in MHC upon peptide binding. We found that irrespective of peptide binding affinity, MHC deformation appears to influence costimulation, which then leads to effective T cell priming and disease induction. Although this study compares in vivo and molecular dynamics results for three altered peptide ligands, further investigation with similar complexes is essential to determine whether spatial rearrangement of peptide-MHC and costimulatory complexes is an additional level of T cell regulation

Conformational Control of the Binding of the Transactivation Domain of the MLL Protein and c-Myb to the KIX Domain of CREB

The KIX domain of CBP is a transcriptional coactivator. Concomitant binding to the activation domain of proto-oncogene protein c-Myb and the transactivation domain of the trithorax group protein mixed lineage leukemia (MLL) transcription factor lead to the biologically active ternary MLL∶KIX∶c-Myb complex which plays a role in Pol II-mediated transcription. The binding of the activation domain of MLL to KIX enhances c-Myb binding. Here we carried out molecular dynamics (MD) simulations for the MLL∶KIX∶c-Myb ternary complex, its binary components and KIX with the goal of providing a mechanistic explanation for the experimental observations. The dynamic behavior revealed that the MLL binding site is allosterically coupled to the c-Myb binding site. MLL binding redistributes the conformational ensemble of KIX, leading to higher populations of states which favor c-Myb binding. The key element in the allosteric communication pathways is the KIX loop, which acts as a control mechanism to enhance subsequent binding events. We tested this conclusion by in silico mutations of loop residues in the KIX∶MLL complex and by comparing wild type and mutant dynamics through MD simulations. The loop assumed MLL binding conformation similar to that observed in the KIX∶c-Myb state which disfavors the allosteric network. The coupling with c-Myb binding site faded, abolishing the positive cooperativity observed in the presence of MLL. Our major conclusion is that by eliciting a loop-mediated allosteric switch between the different states following the binding events, transcriptional activation can be regulated. The KIX system presents an example how nature makes use of conformational control in higher level regulation of transcriptional activity and thus cellular events

Venous Thrombotic Risk in Transgender Women Undergoing Estrogen Therapy: A Systematic Review and Metaanalysis

BACKGROUND: Transgender women are female individuals who were recorded men at birth based on natal sex. Supporting a person's gender identity improves their psychological health, and gender-affirming hormones reduce gender dysphoria and benefit mental health. For transgender women, estrogen administration has clinically significant benefits. Previous reviews have reported conflicting literature on the thrombotic risk of estrogen therapy in transgender women and have highlighted the need for more high-quality research. CONTENT: To help address the gap in understanding thrombotic risk in transgender women receiving estrogen therapy, we performed a systematic literature review and metaanalysis. Two evaluators independently assessed quality using the Ottawa Scale for Cohort Studies. The Poisson normal model was used to estimate the study-specific incidence rates and the pooled incidence rate. Heterogeneity was measured using Higgins I 2 statistic. The overall estimate of the incidence rate was 2.3 per 1000 person-years (95% CI, 0.8-6.9). The heterogeneity was significant (I 2 = 74%; P = 0.0039). SUMMARY: Our study estimated the incidence rate of venous thromboembolism in transgender women prescribed estrogen to be 2.3 per 1000 person-years, but because of heterogeneity this estimate cannot be reliably applied to transgender women as a group. There are insufficient data in the literature to partition by subgroup for subgroup prohibiting the analysis to control for tobacco use, age, and obesity, which is a major limitation. Additional studies of current estrogen formulations, modes of administration, and combination therapies, as well as studies in the aging transgender population, are needed to confirm thrombotic risk and clarify optimal therapy regimens