The Cardiometabolic Health of African Immigrants in High-Income Countries: A Systematic Review.

In recent decades, the number of African immigrants in high-income countries (HICs) has increased significantly. However, the cardiometabolic health of this population remains poorly examined. Thus, we conducted a systematic review to examine the prevalence of cardiometabolic risk factors among sub-Saharan African immigrants residing in HICs.

Downregulation of HLA class I antigens in HIV-1-infected cells.

By means of indirect immunofluorescence analysis we investigated the effect of HIV-1 infection on HLA class I surface antigens. We report here that in CD4+ HeLa cells, in H9 cells, and in peripheral T lymphocytes HLA class I antigens are downregulated following infection with HIV-1. The downregulation is effected at a posttranscriptional level since the amounts of HLA class I specific mRNA are similar in infected and uninfected cells.

Tumor necrosis factor amplifies measles virus-mediated Ia induction on astrocytes.

We describe the induction of Ia on cultured astrocytes by measles virus and the amplification of this induction by tumor necrosis factor (TNF). Measles virus induces Ia on rat astrocytes by direct interaction with these cells. TNF does not induce significant levels of Ia at any dose from 1 to 10,000 units/ml.

Cellular oncogenes and lymphocyte activation.

In normal mouse splenic B and T cells at least two cellular proto-oncogenes are expressed, i.e. c-myc and c-fos.

Kinetics of cellular oncogene expression in mouse lymphocytes. II. Regulation of c-fos and c-myc gene expression.

Newly isolated lymphocytes from mouse spleens express the c-fos oncogene even in the absence of mitogen with maximal mRNA levels 60 min post preparation of single cell suspension, whereas c-myc mRNA levels increase only after mitogenic stimulation with maximal mRNA levels 6 h post stimulation. The half-lives of c-fos mRNA are generally very short; they increase from 14 min (after 30 min of culture) to 70 min (after 2 h of culture). The half-lives of c-myc mRNA decrease from 50 min (at 2 and 6 h post stimulation with concanavalin A) to 12 min (at 48 h post stimulation).

Regulation of IL 2 expression in mitogen-activated murine T lymphocytes.

In mitogen-stimulated mouse spleen cells, the IL 2 gene is only transiently expressed with maximal mRNA steady state levels between 6-14 h post stimulation with Concanavalin A (Con A). This is also reflected by the kinetics of IL 2 release into culture supernatants. Con A-stimulated L3T4+ and Lyt2+ T cell subpopulations express the IL 2 gene and produce IL 2 similarly.

Transcriptional control of mu- and kappa-gene expression in resting and bacterial lipopolysaccharide-activated normal B cells.

When murine resting B cells are polyclonally stimulated by bacterial lipopolysaccharide (LPS) in vitro for a short period of 4 days, they are activated to DNA synthesis and cell division, and they also differentiate to immunoglobulin (Ig)-secreting plasma cells. These two events are accompanied with several qualitative changes at the Ig mRNA level: the disappearance of delta mRNA after stimulation, the switch from membrane to secretory form of mu-mRNA, and the late appearance of IgM joining chain (J-chain) mRNA. There is also a quantitative increase of Ig-gene expression at the level of: Ig gene transcription, mu-, kappa- and J-chain mRNA accumulation, and Ig translation and secretion.

Kinetics of cellular oncogene expression in mouse lymphocytes. I. Expression of c-myc and c-ras-Ha in T lymphocytes induced by various mitogens.

Murine splenic T lymphocytes display maximal cellular myc gene (c-myc) expression already 3 h after concanavalin A stimulation and subsequent down-regulation before the onset of DNA synthesis. Stimulation by leucoagglutinin in the presence or absence of interleukin 2 leads to only low initial levels of c-myc-specific RNA which, however, increase later on. A similar pattern of c-myc expression is shown by the Lyt-2+ T cell subpopulation stimulated with either concanavalin A or leucoagglutinin in the presence of interleukin 2.

Behaviour-associated alopecia areata in mice.

In 5 different mouse strains, we observed alopecic lesions most commonly in male breeding animals kept with C57BL females. Alopecic areas were located most frequently on the head, but were also found over the shoulders, the back and the pelvic regions. Observations gained through time-lapse photography indicate the cause is a slight increase in self-grooming and a dramatic increase in allogrooming by their female partners.

IgM RNA switch from membrane to secretory form is prevented by adding antireceptor antibody to bacterial lipopolysaccharide-stimulated murine primary B-cell cultures.

Bacterial lipopolysaccharide (LPS) induces proliferation of resting primary murine B lymphocytes and their differentiation into Ig-secreting cells. This is accompanied by an increase in the rate of Ig gene transcription and the accumulation of mu heavy chain secretory mRNA. Specific antiantigen receptor antibody (anti-mu) induces resting B cells to proliferation but not differentiation.

High yields of DNA-transfer into mouse L-cells by electropermeabilization.

DNA transfection in mouse L-cells was performed by means of the electropermeabilization technique (U. Zimmermann, G. Pilwat, and F.

Expression of endogenous retroviral glycoprotein 70 by antigen-activated cytotoxic and suppressor T lymphocytes of nice.

Concanavalin A-stimulated murine spleen cells and antigen-stimulated B lymphocytes of normal mice express an antigen that reacts with goat antiserum against glycoprotein (gp) 70. Structural analysis of this antigen characterizes it as endogenous viral gp70 that is most likely of xenotropic origin. Activated nonspecific T suppressor cells and cytotoxic T lymphocytes express endogenous viral gp70, whereas nonactivated mouse T or B lymphocytes do not.

In vitro differentiation of F-9 teratocarcinoma cells does not induce expression of endogenous retroviral glycoprotein.

Undifferentiated F-9 teratocarcinoma cells derived from 129/J mice are induced in vitro to express several differentiation markers. Neither undifferentiated nor differentiated F-9 cells express endogenous retroviral glycoprotein (gp70), although the latter can be productively infected with exogenous retroviruses. This is discussed in context with previous findings that all antigen-activated lymphocytes of all mice express endogenous retroviral gp70.

A modified absorption-reduction method to detect virus-specific hemagglutination inhibiting and neutralizing IgM antibodies.

IgG antibodies are preferentially absorbed by protein A-coupled sepharose beads while most of the IgM and IgA antibodies remain in solution. Even relatively low amounts of virus-specific IgM antibodies can then be detected unequivocally by a decrease of the antibody titer following the treatment with reducing agents. Ethandithiol proved superior to 2-mercaptoethanol in combination with neutralization assays.

Chemical characterization of macrophage cytotoxicity factor, macrophage migration inhibitory factor, T-helper cell-replacing factor and colony-stimulating factor from culture supernatants of concanavalin A-stimulated murine spleen cells.

Supernatants from Concanavalin A-stimulated murine spleen cells were subjected to hydrophobic interaction chromatography on phenyl-Sepharose. Macrophage cytotoxicity factor (MCF), macrophage migration inhibitory factor (MIF), T-helper cell-replacing factor (TRF) and colony-stimulating factor (CSF) were bound at high ionic strength and were released stepwise at low ionic strength. CSF thus could be separated from MCF, MIF and TRF and the bulk of other proteins.

[Soluble mediators as a means of communication between lymphozytes in immune reactions (author's transl)].

Soluble mediators play an important role in the positive and negative regulation of immune reactions. This has been particularly well documented for T-B-cooperation in the humoral immune response to T-dependent antigens. T-helper cells produce a T-cell replacing Factor (TRF) upon mitogenic or antigenic stimulation.