Uptake of Fluorescent Iron Oxide Nanoparticles by Oligodendroglial OLN-93 Cells

To investigate the cellular accumulation and intracellular localization of dimercaptosuccinate-coated iron oxide nanoparticles (D-IONPs) in oligodendroglial cells, we have synthesized IONPs that contain the fluorescent dye BODIPY (BP) in their coat (BP-D-IONPs) and have investigated the potential effects of the absence or presence of this dye on the particle uptake by oligodendroglial OLN-93 cells. Fluorescent BP-D-IONPs and non-fluorescent D-IONPs had similar hydrodynamic diameters and ζ-potentials of around 60 nm and ?58 mV, respectively, and showed identical colloidal stability in physiological media with increasing particle size and positivation of the ζ-potential in presence of serum. After exposure of oligodendroglial OLN-93 cells to BP-D-IONPs or D-IONPs in the absence of serum, the specific cellular iron content increased strongly to around 1,800 nmol/mg. This strong iron accumulation was lowered for both types of IONPs by around 50 % on exposure of the cells at 4 °C and by around 90 % on incubation in presence of 10 % serum. The accumulation of both D-IONPs and BP-D-IONPs in the absence of serum was not affected by endocytosis inhibitors, whereas in the presence of serum inhibitors of clathrin-dependent endocytosis lowered the particle accumulation by around 50 %. These data demonstrate that oligodendroglial cells efficiently accumulate IONPs by an endocytotic process which is strongly affected by the temperature and the presence of serum and that BP-D-IONPs are a reliable tool to monitor by fluorescence microscopy the uptake and cellular fate of D-IONPs.     

N‐Acylated Alanine Methyl Esters (NAMEs) from Roseovarius tolerans,Structural Analogs of Quorum‐Sensing Autoinducers,N‐Acylhomoserine Lactones

The Roseobacter clade is one of the most important bacteria group living in the ocean. Liquid cultures of Roseovarius tolerans EL 164 were investigated for the production of autoinducers such as N‐acylhomoserine lactones (AHLs) and other secondary metabolites. The XAD extracts were analyzed by GC/MS. Two AHLs, Z7‐C14 : 1‐homoserine lactone (HSL) and C15 : 1‐HSL, were identified. Additionally, the extract contained five compounds with molecular‐ion peaks at m/z 104, 145, and 158, thus exhibiting mass spectra similar to those of AHLs with corresponding peaks at m/z 102, 143, and 156. Isolation of the main compound by column chromatography, NMR analysis, dimethyl disulfide derivatization for the determination of the location of the C?C bond and finally synthesis of the compound with the proposed structure confirmed the compound to be (Z)‐N‐(hexadec‐9‐enoyl)alanine methyl ester. Four additional minor compounds were identified as C14 : 0‐, C15 : 0‐, C16 : 0‐, and C17 : 1‐N‐acylated alanine methyl esters (NAMEs). All NAMEs have not been described from natural sources before. A BLASTp search showed the presence of AHL‐producing luxI genes, but no homologous genes potentially responsible for the structurally closely related NAMEs were found. The involvement of the NAMEs in chemical communication processes of the bacteria is discussed.     

Kurze Mitteilungen

Summary To the creamy-yellow colored bases of the rump feathers ofDucula bicolor adheres lipoid and noncolored powder. It is supposed, that the lipoid contains the creamy colour, which apparently is no carotenoid.     

Blast crisis of Philadelphia chromosome-positive chronic myelocytic leukemia (CML). Treatment results of 69 patients

We have studied the clinical courses of 69 patients with blastic crises of Philadelphia chromosome positive CML to identify parameters that were associated with an increased response rate or survival. Cytogenetic analysis at the time of blastic transformation revealed additional chromosome changes in 70% of the patients tested. Bone marrow fibrosis was detected in 58% of evaluable patients. Lymphoblastic transformation was seen in 28% of the patients tested with cell surface marker analysis. The value of 5'-nucleotidase as a marker for distinguishing lymphoid from non-lymphoid blast crisis was confirmed. Of 57 evaluable patients, 23 (40%) responded to therapy (CR/PR longer than 14 days). Median survival was 75 days. Longer survival was related to the following factors: Ph1-chromosome as the only detectable cytogenetic abnormality; lymphoblastic transformation; no bone marrow fibrosis; high percentage of blasts and promyelocytes in the bone marrow, and response to therapy. No prognostic significance was associated with age, sex, Tdt, LDH, spleen size, duration of the chronic phase of the disease, white blood cell count, Hb, platelet count and percentages of basophils, eosinophils, erythroblasts and blasts and promyelocytes in the peripheral blood. These data confirm the poor prognosis of patients with blastic crisis of CML treated by conventional chemotherapy.     

In-vitro induction of some features of hairy cell leukemia in chronic lymphocytic leukemia and immunocytoma cells

In an attempt to induce in vitro differentiation we exposed cells from patients with chronic lymphocytic leukemia (CLL) and with immunocytoma (IC) to 12-0-tetra-decanoylphorbol-13-acetate (TPA) at 160 nM. After 3 to 5 days of culture cells became enlarged and the CLL cells developed a basophilic cytoplasm with an excentric nucleus. In some instances cells with many fine projections were seen. We then employed the monoclonal antibody (MAB) HD 6, which was generated against hairy cell leukemia (HCL) cells and reacts most strongly with such cells but is unreactive with plasmocytoma cells and with most CLL cells. TPA treatment induced a greatly enhanced HD 6 binding in CLL and IC cells compared to controls as demonstrated by indirect immunofluorescence. Cytochemical studies revealed that at the same time an acid phosphatase was induced, which was found to be tartrate-resistant in every instance tested. Thus, several features of HCL can be induced in CLL and IC demonstrating the close relatedness of these entities.     

Determination of fumonisins in corn: Evaluation of two purification procedures

The performance of two solid phase extraction (SPE) purification procedures, used in the determination of fumonlsin B₁ (FB₁), B₂ (FB₂) and B₃ (FB₂) In corn, was evaluated using both thin-layer chromatography (TLC) and high performance liquid chromatography (HPLC). Fewer interferences were observed In extracts prepared using the strong anion exchange (SAX) media, in contrast to those purified on C₁₈ media, where on occasions, visual discernment of the TLC bands was hampered by the presence of interfering compounds. Precipitate formation, resulting In the blocking of SPE cartridges was also encountered when using the C₁₈ procedure. HPLC analyses of extracts prepared by both media indicated that they gave comparable fumonlsin recoveries from naturally contaminated corn samples. The results suggest that the C₁₈ procedure, originally developed for the TLC analyses of FB₁ in mixed feeds, may also be applied to the determination of FB₂ and FB₂. However, where TLC is used quantitatively for fumonlsin levels <1 μg/g, purification of sample extracts on SAX media is recommended.     

Conversion of an IGM secreting immunocytoma in a high grade malignant lymphoma of immunoblastic type

A case involving a 67 year old man with an immunocytoma initially presenting as Waldenstr?m's macroglobulinemia which transformed into a high grade malignant lymphoma of immunoblastic type after treatment with cyclophosphamide and corticosteroids over 5 months is presented. IgM (kappa) present in the serum in the phase of immunocytoma was demonstrated also on the less differentiated cells of the high grade lymphoma. The permanent production of the same immunoglobulin molecule suggests that both morphologically different malignancies derived from one B cell clone.