Hepatitis C virus-Epstein-Barr virus interaction in patients with AIDS

Immortalization of B cells by Epstein-Barr virus (EBV) and their subsequent proliferation leads to B-cell non-Hodgkin's lymphoma in immunocompromised patients. The role of hepatitis C virus (HCV) in B-cell non-Hodgkin's lymphoma has recently been raised, and an interaction between HCV and EBV is supported by recent in vitro experiments. The aim of this study was to investigate in vivo interactions between HCV and EBV in patients with AIDS, i.e., patients exposed to the risk of EBV-related B-cell non-Hodgkin's lymphoma. A total of 135 patients were prospectively studied. Serological and molecular markers of HCV, EBV, and human immunodeficiency virus (HIV) infection were sought. All the patients harbored latent EBV infection, and 20% had detectable HCV RNA in serum. No significant relationship was found between HIV, HCV, and EBV viral load in peripheral blood mononuclear cells or plasma. There was no difference between anti-HCV-positive and -negative patients or between HCV RNA-positive and -negative patients with regard to the prevalence of EBV markers, especially EBV replication markers. The presence of EBV replication markers was not related to HCV RNA seropositivity or to HCV viral load. Five patients subsequently developed B-cell non-Hodgkin's lymphoma, none of whom had markers of EBV or HCV replication. These results argue against an in vivo interaction between HCV and EBV in patients with AIDS, and against a role of HCV infection in the occurrence of B-cell non-Hodgkin's lymphoma in these patients.     

Nucleus labeling or membrane labeling for studying the proliferation of drug treated cells?

Proliferation and multidrug resistance status are key predictors of therapeutic outcome in acute myeloid leukemia (AML). This study compared cell cycle analysis (nuclear labeling) with cell division analysis (membrane labeling, PKH67) for studying the proliferation of cells cultured with daunorubicin (DNR) and/or Cytarabine (Ara-C), drugs commonly used in AML treatment. PKHs are a family of lipophilic, fluorescent membrane intercalating dyes. When labeled cells divide, the resulting daughter cells receive half the label, reducing fluorescence intensity to one-half that of the parent cells. DNR has the disadvantage of overlapping the spectrum of propidium iodide (PI), which is the most commonly used marker of membrane integrity. In this study, necrosis was evaluated using TOTO-3, a marker of nucleic acids emitting fluorescence above 645 nm and which incorporates cells with disrupted membranes. Comparison of cell cycle analysis with cell division for studying proliferation revealed that PKH67 was a marker of choice for analyzing the mitotic process in cells cultured with drugs.     

Interference of hyperleukocytosis on Coulter Counter Model S blood counts: methods for correction

Hyperleukocytosis leads to an overestimation of the determination by Coulter Counter Model S of erythrocyte count, hemoglobin, MCV and packed cell volume. These overestimations are proportional to the number of leukocytes above a certain limit, and, for the MCV and PCV, depend on the type of leukocytes present. Regression lines have been calculated which allow for correction of the values obtained.     

The detection of rare cellular events using scanning cytometry

Preliminary studies are presented on the detection of the rare event cell using the Samba 200 cell image analyzer. The simple models used permitted us to define the technical parameters of this detection. It appeared possible to detect as low as one cell per 3.10(6).     

Herpes simplex virus antigen detection in human acute encephalitis:

Summary The distribution of type I, III, IV and V collagen in 35 gliomas and 20 meningiomas was studied by indirect immmunofluorescence staining. In addition, the presence of fibronectin (FN) and laminin (LN) is also reported. In gliomas expression of type IV collagen and LN was found in the vessel walls and associated with the endothelial glomerulus-like proliferations. FN and type V collagens were located in proliferating vessel walls in a pattern corresponding both to the basement membrane and the perivascular matrix around the vessels. In the extracellular matrix of grade III and IV gliomas occasional faint intercellular fluorescence was also observed with both FN and type V collagen. Type I and III collagens were localised in the vessel walls and in the perivascular connective sheet. Glioma cells did not express any of the antigens investigated. In meningiomas, type IV and V collagens, LN and FN were found in vessel walls, whorls formations and psammoma bodies. These stainings support the hypothesis of a vascular origin of these psammoma bodies which were only found in syncytial and transitional meningiomas. Both type I and III collagens were detected in the perivascular connective tissue. In general, meningioma cells and extracellular matrix did not express any of these molecules, except in transitional meningiomas where occasional fluorescence was observed in extracellular matrix with type V collagen and FN.     

Correlation between milk and dairy product consumption and multiple sclerosis prevalence: a worldwide study.

Multiple sclerosis (MS) epidemiology suggests that different factors are involved in the clinical expression of the disease. Alimentary cofactors have already been considered, but mainly theoretically. We have studied the relationship between MS prevalence and dairy product consumption in 27 countries and 29 populations all over the world, with Spearman's correlation test. A good correlation between liquid cow milk and MS prevalence (rho = 0.836) was found; this correlation was highly significant (p < 0.001). A low but still significant correlation was obtained with cream or butter consumption (rho = 0.619 and rho = 0.504, respectively). No correlation was found for cheese. These results suggest that liquid cow milk could contain factor(s) - no longer present in the processed milk - influencing the clinical appearance of MS. The possible role of some dairy by-products is discussed in the light of a multifactorial etiology of MS.