This investigation examined the effects of environmental alteration on the virulence of the oral treponemes Treponema denticola and Treponema pectinovorum. The environmental effects were assessed by using a model of localized inflammatory abscesses in mice. In vitro growth of T. denticola and T. pectinovorum as a function of modification of the cysteine concentration significantly enhanced absc...

Naturally quiescent human lymphocytes, consisting predominantly of T cells, contain mRNA(s) that can inhibit DNA synthesis when injected into either human diploid fibroblasts (IMR-90) or transformed recipient cells (HeLa). By using an automated capillary microinjection system and a fluorescent coinjection marker (fluorescein isothiocyanate-dextran), individually injected cells can be retrieved ...

The neurons within the segmented hindbrain of the early chick embryo have been mapped with the neuronal tracers HRP and fluorescent lysinated dextran. We have categorised neurons according to their axonal pathways and have then compared rhombomeres with respect to the number and class of neurons present. The results indicate that most rhombomeres are similar in that they contain the same set of...

By WILLIAM A. SKOOG AND WILLIAM S. BECK T HE INCREASING INTEREST in leukocyte biochemistry and physiology is largely attributable to the invention of satisfactory simple procedures for the isolation of leukocytes from whole blood. Although some of these methods involve selective destruction of the red cells, the most useful procedures seem to be those based upon the differences in sedimentation...

Justificativa e Objetivos A cefaléia pós-punção de duramáter é uma complicação bem conhecida das anestesias subaracnóideas e peridurais, sendo o tampão sangüíneo considerado o tratamento mais eficaz, até o momento. Este é um procedimento invasivo e sujeito a complicações graves. Seu uso em certos pacientes, como portadores de HIV ou leucemias, é motivo de debate. Várias alternativas têm sido re...

We used atomic force microscopy (AFM) and surface plasmon resonance (SPR) to study the surface conformations of an anti-ricin aptamer and its specific binding affinity for ricin molecules. The effect of surface modification of the Au(111) substrate on the aptamer affinity was also estimated. The AFM topography images had a resolution high enough to distinguish different aptamer conformations. T...

The mechanism of adherence of Streptococcus mutans to smooth glass surfaces has been studied. The results with both viable and heat-killed cells showed that the process required (i) the synthesis of a water-insoluble dextran-levan polymer by cell-bound enzymes and (ii) the participation of a binding site on the surface of the S. mutans cell. Synthesis of the polymer from sucrose in the presence...

Methotrexate (MTX) is widely used in the treatment of a number of oncological and hematological diseases. Due to its known limitations, MTX is often conjugated with different carriers to obtain amended forms of the drug. In this study, the potential influence of the substitution level (loading ratio) of the dextran T10- and T40-based MTX conjugates (D-MTX) on their properties were investigated ...

After phagocytosis by mammalian macrophages, promastigote forms of Leishmania parasites settle inside intracellular parasitophorous vacuoles (PVs) in which they transform into amastigote forms and replicate. Here, using a variant of the 'inverted emulsion' method, we succeeded in encapsulating living L. amazonensis parasites in giant artificial liposomes that serve as model PVs. We were able to...

BACKGROUND Intravenous iron therapy is a treatment option for iron deficient patients who are intolerant to oral iron or where oral iron is ineffective, but with possible adverse effects. Currently, prospective studies comparing different intravenous iron formulations are needed to determine safety and efficacy of these agents. METHODS We conducted a prospective, double-blind, randomized cont...