Regional cerebral blood flow and oxygen metabolism during migraine with and without aura

Eleven cases of migraine with and without aura were investigated with positron emission tomography (PET). Regional cerebral blood flow (rCBF), oxygen metabolism (rCMRO₂) and oxygen extraction (rOER) were measured during baseline ( n =11), aura ( n = 6), headache ( n = 10) and after treatment with sumatriptan ( n = 4). Data were analysed using and ROI-based approach from 26 different anatomically defined regions, and also an exploratory approach whereby all subjects were normalized to a stereotactic brain atlas; t -maps were constructed by depicting significant changes between states. The exploratory approach revealed a region corresponding to the primary visual cortex with significant reductions in rCBF (23.1%) and rCMRO₂ (22.5%), but no change in rOER during the headache phase compared to baseline. These data suggest that cerebral ischemia was not the primary cause of the attacks in these cases.     

人类染色体17p13.3位点新克隆基因HC56,HC71 和HC90在白血病细胞的表达

为研究人类染色体17p13．3位点新克隆的基因HC56，HC71和HC90在白血病细胞中的表达，应用同位素标记的、以βM2基因作为内参的半定量RT—PcR法，检测35例急性白血病和4株白血病细胞系的Hc56，Hc70和HC90基因的表达。结果显示，急性淋巴系白血病病人的HC90基因和T淋巴系白血病细胞系Jurkat细胞HC90基因表达水平降低。急性髓系白血病病人HC71基因表达水平降低。HC56基因表达在急性白血病和正常对照间未见显差异。结论：在人类白血病有HC70和HC90的基因表达异常。     

Protection against mouse and avian influenza A strains via vaccination with a combination of conserved proteins NP, M1 and NS1

Background Experimental data accumulated over more than a decade indicate that cross‐strain protection against influenza may be achieved by immunization with conserved influenza proteins. At the same time, the efficacy of immunization schemes designed along these lines and involving internal influenza proteins, mostly NP and M1, has not been sufficient. Objective To test the immunogenicity and protective efficacy of DNA vaccination with a combination of NP, M1 and NS1 genes of influenza virus. Methods The immunogenicity and protective efficacy of DNA vaccination with NP, M1 and NS1 was tested in mice and chickens. Mice were challenged with mouse‐adapted viral strains H3N2 and H5N2 and chicken challenged with avian H5N3 virus. Results In these settings, wild‐type NS1 did not impede the cellular and humoral response to NP/M1 immunization in vivo. Moreover, addition of NS1‐encoding plasmid to the NP/M1 immunization protocol resulted in a significantly increased protective efficacy in vivo. Conclusions The addition of NS1 to an influenza immunization regimen based on conserved proteins bears promise. It is feasible that upon further genetic modification of these and additional conserved influenza proteins, providing for their higher safety, expression and immunogenicity, a recombinant vaccine based on several structural and non‐structural proteins or their epitopes will offer broad anti‐influenza protection in a wide range of species.     

Upregulation of antithrombotic ectonucleotidases by aspirin in human endothelial cells in-vitro

Abstract— Ecto ATP-diphosphohydrolase (apyrase) activity of human endothelial cells following aspirin treatment has been studied in-vitro. It was shown by HPLC analysis of supernatant samples that pre-incubation of the cultures with aspirin resulted in a significantly increased turnover of supplemented ATP into its degradation products (ADP and AMP). Enhanced expression of ectoenzyme after aspirin treatment could be observed as demonstrated by immunofluorescence-staining with monoclonal anti-apyrase antibodies. This suggests enhancement of endothelial ATP-diphosphohydrolase activity induced by aspirin. The present data obtained in human vascular cells in-vitro are in line with results from previous animal studies in-vivo, suggesting a novel cyclo-oxygenase-independent antithrombotic activity of aspirin.     

Analysis of retroviral proteins by two-step DNA, zinc binding, and modified Southern-western blotting.

Using Southern-Western and zinc-blotting techniques, the interactions of single-stranded DNA and zinc with structural proteins of type B, C, and D retroviruses were examined. Besides nucleic capsid proteins of retroviruses known to form complexes with nucleic acids, some other core proteins of type C retroviruses were shown to bind nucleic acids. All nucleic capsid proteins of the examined retroviruses appeared to be also zinc binding. In the present report, we propose two protein-blotting techniques that could be performed on a single nitrocellulose membrane. A first technique allows to detect zinc- and DNA-binding proteins immobilized on the membrane; a second (a modification of Southern-Western blotting) makes it possible to detect DNA-binding proteins followed by immunological reprobing.     

In vitro proliferation of hematopoietic stem cells in the absence of an adherent monolayer

Experiments on long-term murine bone marrow cultures indicate that the production and maintenance of the hematopoietic stem cell is dependent on the establishment of an adherent monolayer and a secondary repopulation of the culture with fresh marrow. In contrast, we have found that bone marrow cultures derived from the Syrian hamster do not require a repopulation step and produce stem cells that proliferate and differentiate for more than 12 wk in the absence of an adherent layer. Stem cells were grown in Fisher's medium (pH 7.0-7.2) containing 20% horse serum in a fully humidified atmosphere of 5% CO2 in air at 37 degrees C. Cultures were fed twice weekly by removal of half of the medium and supernatant cells and replacement with an equal volume of fresh medium. No hormones or exogenous growth factors were required for the maintenance of myeloid cells, monocytes, and megakaryocytes in either the adherent or suspension cells cultures.     

Presence of mixed colony-forming cells in long-term hamster bone marrow suspension cultures: response to pokeweed spleen conditioned medium

In contrast to the murine system, long-term hamster bone marrow suspension cultures maintain proliferation of both pluripotent and committed stem cells in the absence of an adherent layer and without addition of exogenous factors, such as hydrocortisone. Addition of pokeweed-mitogen-stimulated hamster spleen conditioned medium (SCM) to these long-term suspension cultures produces an increase in the number of mixed colonies assayed in soft-agar, These mixed colonies, which contained four cell lineages--granulocytic, erythroid, megakaryocytic, and macrophage--could be generated from cells grown in suspension for over 6 mo. Addition of SCM also induces an initial rapid expansion of the myeloid compartment, and this expansion results in 70% of the cells being terminally differentiated granulocytes. In contrast, addition of SCM to hamster bone marrow cultures containing both adherent cells and hematopoietic stem cells produced no change in the number of mixed colonies generated in the culture. This system allows the in vitro study of the process of stem cell proliferation and differentiation and also provides a means to examine the relationship of adherent and supernatant bone marrow populations.