Human erythrocytes under stress. Spectroscopic fingerprints of known oxidative mechanisms and beyond.

In this work, we investigated the oxidative stress-related biochemical alterations in red blood cells (RBCs) and their membranes with the use of spectroscopic techniques. We aimed to show their great advantage for the in situ detection of lipid classes and secondary structures of proteins without the need for their extraction in the cellular environment. The exposition of the cells to peroxides, t-butyl hydroperoxide (tBOOH) or hydrogen peroxide (HO) led to different degradation processes encompassing the changes in the composition of membranes and structural modifications of hemoglobin (Hb).

Reversible posterior leukoencephalopathy syndrome in a child treated with bevacizumab.

Bevacizumab is a monoclonal antibody targeting vascular endothelial growth factor (VEGF). Hypertension is a well-recognized, common side effect of VEGF blocking agents. The reversible posterior leukoencephalopathy syndrome (RPLS) has been described as a rare but serious consequence of bevacizumab administration.

Defective suppressor cell function mediated by T8+ cell lines from patients with progressive multiple sclerosis.

Activated suppressor cell function, induced with either concanavalin A or OKT3 and mediated by either unfractionated mononuclear cells or "panning" enriched T8+ cells, freshly isolated from peripheral blood, is reduced in patients with progressive multiple sclerosis (MS) as compared with control donors. In this study, we generated T8+ cell lines from the peripheral blood of these same patients and controls. Suppressor activity, mediated by T8+ cells exposed to OKT3 on days 1, 7, and 14 of culture and then treated with mitomycin C on day 16, was significantly reduced in the MS group (mean percent suppression 13% +/- 5) as compared with the control group (68% +/- 6, n = 8, p less than 0.

Neuroleukin: a lymphokine product of lectin-stimulated T cells.

Neuroleukin is a lymphokine product of lectin-stimulated T cells that induces immunoglobulin secretion by cultured human peripheral blood mononuclear cells. Neuroleukin acts early in the in vitro response that leads to formation of antibody-secreting cells, but continued production of immunoglobulin by differentiated antibody-secreting cells is neuroleukin-independent. Although the factor is not directly mitogenic, cellular proliferation is a late component of the response to neuroleukin.

Comparison of T8+ cell-mediated suppressor and cytotoxic functions in multiple sclerosis.

Patients with progressive multiple sclerosis (MS) and controls were compared with regard to: (a) in vitro pokeweed mitogen (pwm)-induced IgG secretion, as an indirect measure of T8+ cell-mediated suppressor function; (b) alloantigen-directed cytotoxic activity, a predominantly T8+ cell-mediated function. The MS group had increased IgG secretion (4790 +/- 372 ng/ml vs. 1866 +/- 233 ng/ml, P less than 0.

Suppressor and cytolytic cell function in multiple sclerosis. Effects of cyclosporine A and interleukin 2.

Patients with progressive multiple sclerosis (MS) demonstrated persistent reductions in levels of concanavalin A (Con A)-induced suppressor activity and heightened levels of in vitro pokeweed mitogen (PWM)-induced IgG secretion. The reduced Con A suppressor activity could not be reversed by addition of interleukin 2 (IL-2). Cyclosporine A (CsA) treatment did not alter the defect in Con A-induced suppressor activity, but did markedly inhibit T8+ cell-mediated alloantigen directed cytolytic activity; this latter defect was reversible by in vitro addition of IL-2.

Activated suppressor cell dysfunction in progressive multiple sclerosis.

Concanavalin A (Con A)-induced suppressor activity has previously been shown to be reduced in multiple sclerosis (MS) patients with active clinical disease. In this study, we demonstrate that OKT3, as well as Con A induced suppressor activity mediated by unfractionated peripheral blood mononuclear cells is reduced in patients with the progressive form of MS. By performing reconstitution experiments involving E+, T4+, or T8+ cells derived from either MS patients or controls, and normal allogeneic macrophages or E- cells, we sought to define the cellular basis for this suppressor defect.

Dissociation of T8+ cell-mediated cytolytic and suppressor functions in young adults.

In the normal young adult population, in vitro levels of polyclonally-induced IgG secretion by mononuclear cells (MNCs) vary widely amongst individuals. Levels of IgG secretion correlate with functional suppressor activity of T8+ cells but not with their proportion within the MNCs either prior to culture, or as found in this study, at the end of the culture period. The current study also demonstrates a lack of correlation between T8+ cell-mediated suppressor (Ts) function and a second predominantly T8+ cell-mediated function, alloantigen-directed cytolytic (Tc) activity.

Senile dementia of Alzheimer's type (SDAT): reduced T8+-cell-mediated suppressor activity.

We compared patients with senile dementia of the Alzheimer's type (SDAT) and age-matched controls with respect to T8+-cell-mediated suppressor function using a pokeweed mitogen (pwm)-induced IgG secretion assay. The responding B cells were allogeneic to the T-regulator cells. T8+-cell-mediated suppression was lower in SDAT patients than the controls when we used either 2 X 10(4) or 5 X 10(4) T8+ cells.

Age-related changes in mechanisms accounting for low levels of polyclonally induced immunoglobulin secretion in humans.

The mechanisms accounting for low levels of T-cell-dependent polyclonal IgG secretion in old and young human adults were compared. In elderly donors, in contrast to young donors, low levels of IgG secretion by unfractionated mononuclear cells (MNCs) did not correlate with functional suppressor activity of "panning"-enriched T8+ cells. Levels of IgG secretion by MNCs did not correlate either with proportions of T8+ or T4+ cells in the MNC population or with the functional helper activity of panning-enriched T4+ cells, in either old or young age groups.