Topical Modes in the Preparation of Human Spleen Specimens for Routine Scanning Electron Microscopy Studies

Various preparatory techniques were used to improve scanning electron microscopy images of the fine structure of vascular, cellular, and cordal-reticular components of normal human spleens. The progressive method of fixation (GTGO) applied in the present study, allowed air drying of the tissues and rendered the specimens conductive even in newly fractured surfaces. Vascular perfusion proved necessary only in studies of the splenic blood vessels, while a simple immersion of tissue blocks in the washing solution resulted in better images of the white pulps. Interstitial (trans-splenic) perfusion was found to be superior to vascular perfusion for routine preparation of spleen tissues, and freeze-cracking did not necessarily lead to improved images of the specimen\u27s surfaces. Combined with proper washing and shaping protocols, the GTGO procedure is shown to be a superior mode of specimen preparation, abolishing most traditional artifacts and obtaining clear images of the complex splenic tissue

Adhesion, Spreading and Fragmentation of Human Megakaryocytes Exposed to Subendothelial Extracellular Matrix: A Scanning Electron Microscopy Study

Platelet agonists and subendothelial extra-cellular matrix (ECM) induce morphological and biochemical changes in animal megakaryocytes, reminiscent of the response of platelets to the same substances. We have examined the behavior of human megakaryocytes exposed for up to 36 hours to the ECM produced by cultured bovine corneal endothelial cells. By phase contrast and scanning electron microscopy these megakaryocytes demonstrated non-reversible adherence and flattening with formation of long filopodia, thus confirming that human megakaryocytes acquire platelet functional capacities. In addition, megakaryocyte fragmentation into prospective platelets was apparently induced by the ECM. Up to 50% of the adherent megakaryocytes underwent spontaneous fragmentation into small particles which individually reacted like platelets on the ECM. The interaction of the megakaryocytes with the ECM was specific since no adherence, flattening or fragmentation occured upon incubation of the megakaryocytes on regular tissue culture plastic or glutaraldehyde fixed ECM. Thus we have demonstrated platelet like behaviour of human megakaryocytes in response to this physiological basement membrane and a possible role of the subendothelium in platelet production which may occur in vivo as megakaryocytes cross the sinusoid walls and enter the blood stream

T-cell project: an international, longitudinal, observational study of patients with aggressive peripheral T-cell lymphoma

Peripheral T-cell lymphomas (PTCLs) comprise a heterogeneous group of neoplasms that are derived from post-thymic lymphoid cells at different stages of differentiation and with different morphological patterns, phenotypes, and clinical presentations. PTCLs are highly diverse, reflecting the diverse cells from which they can originate and are currently sub-classified using World Health Organization (WHO) 2008 criteria. Peripheral T-Cell Lymphomas account for 5%-10% of all lymphoproliferative disorders in the Western hemisphere, with an overall incidence of 0.5-2 per 100,000 individuals per year, and have a striking epidemiological distribution, with higher incidence in Asia. The clinical features of PTCL are extremely heterogeneous. PTCLs express even more clinical diversity than B-cell non-Hodgkin's lymphomas, and there is a close, though not absolute, relationship between some unusual clinical features and certain histological subtypes

Predictive value of the CLL-IPI in CLL patients receiving chemo-immunotherapy as first-line treatment

An international collaboration has led to the development of a comprehensive tool [CLL-IPI international prognostic index for CLL] for the predicting of overall survival (OS) in chronic lymphocytic leukemia (CLL).1 CLL-IPI was based on data collected from 3500 CLL patients and was based on the following parameters: TP53 deletion and/or mutation, IGHV mutational status, \u3b22-microglobulin plasma levels, clinical stage, and age. CLL-IPI provides the means to stratify CLL patients in the daily clinical practice (Supplementary Table 1).1 Although validated for OS2-4 and time to first treatment (TTFT),5 the predictive value of CLL-IPI on progression-free survival (PFS) has until now only been demonstrated in a single study on patients treated with chlorambucil (CLB), as monotherapy, or in combination with obinutuzumab or rituximab, as a first-line approach (CLL11 study),6 and presented as a poster at the annual meeting of the American Society of Hematology (ASH) in 2016

Ibrutinib as initial therapy for patients with chronic lymphocytic leukemia

Background: chronic lymphocytic leukemia (CLL) primarily affects older persons who often have coexisting conditions in addition to disease-related immunosuppression and myelosuppression. We conducted an international, open-label, randomized phase 3 trial to compare two oral agents, ibrutinib and chlorambucil, in previously untreated older patients with CLL or small lymphocytic lymphoma. Methods: we randomly assigned 269 previously untreated patients who were 65 years of age or older and had CLL or small lymphocytic lymphoma to receive ibrutinib or chlorambucil. The primary end point was progression-free survival as assessed by an independent review committee. Results: the median age of the patients was 73 years. During a median follow-up period of 18.4 months, ibrutinib resulted in significantly longer progression-free survival than did chlorambucil (median, not reached vs. 18.9 months), with a risk of progression or death that was 84% lower with ibrutinib than that with chlorambucil (hazard ratio, 0.16; P<0.001). Ibrutinib significantly prolonged overall survival; the estimated survival rate at 24 months was 98% with ibrutinib versus 85% with chlorambucil, with a relative risk of death that was 84% lower in the ibrutinib group than in the chlorambucil group (hazard ratio, 0.16; P=0.001). The overall response rate was higher with ibrutinib than with chlorambucil (86% vs. 35%, P<0.001). The rates of sustained increases from baseline values in the hemoglobin and platelet levels were higher with ibrutinib. Adverse events of any grade that occurred in at least 20% of the patients receiving ibrutinib included diarrhea, fatigue, cough, and nausea; adverse events occurring in at least 20% of those receiving chlorambucil included nausea, fatigue, neutropenia, anemia, and vomiting. In the ibrutinib group, four patients had a grade 3 hemorrhage and one had a grade 4 hemorrhage. A total of 87% of the patients in the ibrutinib group are continuing to take ibrutinib. Conclusions: ibrutinib was superior to chlorambucil in previously untreated patients with CLL or small lymphocytic lymphoma, as assessed by progression-free survival, overall survival, response rate, and improvement in hematologic variables. (Funded by Pharmacyclics and others; RESONATE-2 ClinicalTrials.gov number, NCT01722487.)