Changes in the lymphatic system in the crush syndrome]

In vivo indirect electrolymphoroentgenography was conducted to study the reaction of lymphatics during prolonged compression syndrome (PCS). The studies were made on white rats, Wistar-line, males. It was found out that the early period of clinical course of PCS was characterized by lymphostasis. The intermediate period of PCS corresponds to the stage of the collateral lymphokinesis. At the edge of intermediate and late period of PCS the electrolymphoroentgenogram shows the removal of lymphostasis and recovery of main lymphokinesis.     

Two new large deletions resulting in epsilon gamma delta beta-thalassemia

Detailed gene mapping data are provided for members of a Yugoslavian and Canadian family with a thalassemia heterozygosity characterized by mild anemia with severe microcytosis and hypochromia, normal levels of Hb A2 and slightly raised Hb F levels. The condition in both families results from large deletions (minimally approximately 148 kb in the Yugoslavian family and minimally approximately 185 kb in the Canadian family), which include all functional and psi genes of the beta globin gene cluster. The Canadian propositus was a newborn baby who has been followed for nearly 2 years; severe anemia developed some 30-40 days after birth when the Hb F level was still 70%; recovery was evident at the age of 90 days when the Hb F level had decreased to 40%.     

Sustained signaling through the B-cell receptor induces Mcl-1 and promotes survival of chronic lymphocytic leukemia B cells

The clinical course of chronic lymphocytic leukemia (CLL) differs significantly between patients with mutated (M-CLL) and unmutated (U-CLL) immunoglobulin (Ig) variable heavy-chain (V(H)) genes, implying a role for B-cell receptor (BCR) signaling in the pathogenesis of this disease. We have now investigated activation of downstream BCR signaling pathways in U-CLL and M-CLL B cells using soluble anti-IgM (sol-IgM) and immobilized anti-IgM (imm-IgM) antibodies as models for antigenic stimulation. Ligation of the BCR with sol-IgM induced incomplete responses in both CLL subsets, resembling the pattern described for tolerant B cells. This response was characterized by transient phosphorylation of extracellular signal-related kinase (ERK) and Akt (protein kinase B [PKB]), lack of activation of c-JUN NH2-terminal kinase (JNK) and p38 mitogen-activated protein kinase (MAPK), and variable activation of phospholipase Cgamma2 (PLCgamma2) and nuclear factor-kappaB (NF-kappaB). Stimulation with imm-IgM elicited a more complete BCR signal and significantly prolonged phosphorylation of ERK and Akt, indicating persistent or repetitive BCR signaling. Moreover, this type of stimulation increased the levels of the antiapoptotic protein myeloid cell leukemia-1 (Mcl-1) and protected from chemotherapy-induced apoptosis, whereas induction of apoptosis and down-regulation of Mcl-1 was observed following stimulation with sol-IgM. These data demonstrate that only sustained BCR signaling can promote survival of CLL B cells and indicate that the main difference between CLL with mutated and unmutated V(H) genes may reside in the availability of such stimulation.