Neutrophilic thrombophagocytosis.

Platelets phagocytosed by neutrophils is a rare morphological finding on peripheral blood films. It is rarely an EDTA-dependent artifact but mainly caused by an active vascular inflammation process. Here is reported an unexpected observation of neutrophilic thrombophagocytosis, in the context of a disseminated Streptococcus pneumoniae infection.

Non-Hodgkin's lymphomas with Burkitt-like cells are associated with c-Myc amplification and poor prognosis.

Out of 344 patients with newly diagnosed non-Hodgkin's lymphoma (NHL), this study identified 16 patients presenting Burkitt-like cells (BLCs) after cytological and/or histological review. Conventional cytogenetic analysis showed at diagnosis complex chromosomal abnormalities in 13 cases and a normal karyotype in three cases. However, neither t(8;14)(q24;q32) nor the variants t(2;8)(p12;q24) or t(8;22)(q24;q11) was detected. FISH studies showed c-MYC amplification in all cases with four to more than seven copies in 10 - 77% metaphase or inter-phase cells. This study did not observe any gene fusion signal for c-MYC/IgH excluding a t(8;14) translocation and partial tri or polysomy of chromosome 8. It also excluded in that cases a break apart for the c-MYC locus. This study also never detected IgL/c-MYC, IgK/c-MYC or X-c-MYC. The BLCs were present whatever the lymphoma sub-type: follicular lymphoma (FL) was diagnosed in six out of 16 patients, mantle cell lymphoma (MCL) in four out of 16 patients, marginal zone lymphoma (MZL) in two out of 16 patients and diffuse large B-cell lymphomas (DLBCL) in three out of 16 patients. One additional patient presented a T-cell lymphoma. The clinical course was aggressive with a poor prognosis, as death occurred in nine patients, within 6 months after diagnosis for eight of them. These data could suggest a sub-group of NHL patients (15 B-NHL, 1 T-NHL) have been identified with a poor prognosis characterized by the association of Burkitt-like cells and c-MYC amplification without t(8;14)(q24;q32) or its variants. The possibility that this profile may represent a distinct morphologic NHL sub-set remains to be determined on a large cohort of patients.

[Evaluation of the blood analyzer Beckman Coulter LH 750: analytic performance, decision rules]. / Evaluation de l'analyseur d'hématologie Beckman Coulter LH 750: performances analytiques, règles de décision.

We evaluated the new analyzer Beckman Coulter, an instrument dedicated to the cell blood count (CBC) and to the white blood cell (WBC) differential (including nucleated red blood cells (NRBCs)) over a global one month period, with three purposes: 1) evaluation of the analytical performance (precision, reproducibility, contamination, linearity); 2) accuracy of numerical results, by comparison to the laboratory instrument (CBC and WBC diff) or to the blood smear (NRBCs, low platelets); 3) evaluation, in terms of sensitivity and specificity, a set of abnormality messages built from the suspect flags and a few quantitative abnormalities. The analytical performances were found satisfactory. The WBC and platelet ranges of linearity were wider than in the GEN.S, as stated in the system specifications. However, the lack of adequate biological material made impossible the study of the whole mentioned linearity range. The accuracy of the CBC and differential parameters, as well as of reticulocytes, was studied with the Coulter GEN.S as reference instrument. The coefficients of correlation and the regression lines showed that the LH 750 results were similar to the GEN.S results. Furthermore, samples with thrombocytopenia and circulating NRBCs were evaluated and compared to the result obtained with microscopic lecture. The results showed a good relationship between platelets results given by the GEN.S and manual count leading to appropriate decision of transfusion. The correlation between GEN.S and manual count of NRBC was estimated as satisfactory. We used the LH 750 software to create conditional rules on the basis of qualitative and quantitative criteria, in order to define and enter a message system for detection of abnormalities. Our study showed that such a system flagged 95.7% of morphological abnormalities with a rate of unnecessary slide review (absence of any morphological abnormality on the blood smear) estimated at 8.3%. Furthermore, in 86% of the abnormalities studied, the relevant message was triggered. The Beckman Coulter LH 750 thus appeared as suitable in terms of validation efficiency.

Two new Ggamma chain variants: Hb F-clamart [gamma17(A14)Lys-->Asn] and Hb F-Ouled Rabah [gamma19(B1)Asn-->Lys].

Two new fetal hemoglobin variants affecting the Ggamma chain are reported. Hb F-Clamart was found during investigation of a French newborn who presented with a mild microcytemia. The second variant was found during neonatal screening for hemoglobinopathies of 30,000 babies from a population-at-risk living in the Paris region. It was named Hb F-Ouled Rabah because its structural modification and ethnic distribution is similar to that of Hb D-Ouled Rabah [beta19(B1)Asn-->Lys]. Hb F-Ouled Rabah is clinically silent and occurs at a frequency of ca. 0.1% in newborns originating from Maghreb. Structural characterization of both variants was done by protein chemistry methods, including amino acids analysis and mass spectrometry.

Mechanisms of cytotoxicity by cosmetic ingredients in sea urchin eggs.

The acute cytotoxicities of four cosmetic ingredients: a preservative, imidazolidinylurea (IU) and three mild surfactants, cocamido propyl hydroxy sultaine (CAS), magnesium laureth sulfate (Mg LES), and decyl glucoside (APG) were studied using sea urchin eggs. The cellular targets of these compounds were identified by studying the effects on calcium homeostasis, intracellular pH, sodium and potassium contents, protein and DNA synthesis, and protein phosphorylation. These compounds inhibited the first cleavage of sea urchin eggs in a dose-dependent fashion with half maximal doses (IC50) from 30 microg/ml for Mg LES, 60 microg/ml for IU, 83 microg/ml for CAS, to above 400 microg/ml for APG. The time at which a compound showed the greatest toxicity to the cell cycle was definable for APG (between 20 and 50 min postfertilization) and IU (from fertilization to 50 min later); the other compounds being toxic throughout division. Compounds exhibited toxicity to a wide range of cellular targets. IU, the least toxic, mainly operates through inhibition of protein and DNA syntheses. CAS and Mg LES produced nonspecific cytotoxicity related to alterations of membrane and endomembrane permeabilities resulting in ionic disequilibrium (Na+, K+, Ca2+) and inhibition of intracellular storage of Ca2+. The APG effect mainly involved intracellular pH and DNA synthesis, a hypothesis suggested by the narrow postfertilization period of maximal toxicity.

Chronic lymphocytic leukaemia with binucleated lymphocytes.

Chronic lymphocytic leukaemia (CLL) is a monoclonal proliferation usually involving B cells and composed of mature lymphoid cells. Distinct morphologic subtypes have been recognized according to lymphocyte size, nuclear:cytoplastic ratio and nucleolus. However the presence of characteristically binucleated lymphocytes in patients fulfilling criteria for CLL diagnosis has never been described. We here report immunological and cytogenetic studies of four patients with CLL but with binucleated lymphocytes. Moreover, trisomy 12, known to be associated with atypical morphology in CLL, was detected in two of these four patients. We suggest that this be considered as a possible new entity.