Association of serum IgA and C4 with severe atherosclerosis

To assess the possible involvement of humoral immunity in diffuse atherosclerosis, IgG, IgA, IgM, C3 and C4 were measured in the sera of 23 atherosclerotic subjects (at least 3 stenoses greater than 75% in the arteries of the limbs and neck, as assessed by panangiography) and of 20 controls (possible stenoses less than 40% documented by arteriography of the aortic arch and epi-aortic branches and "normal" response to exercise stress testing and Doppler ultrasonography of the arteries of the lower limbs). Age (59-69) and sex distribution did not differ significantly in the 2 groups. The following serum concentrations were higher in the atherosclerotic subjects than in the controls: C4 (28.7 +/- 6.5 (1 SD) vs. 23.4 +/- 3.8 mg/dl; P = 0.0013); IgA (323.3 +/- 155.0 vs. 210.3 +/- 87.9 mg/dl; P = 0.0020); and C3 (126.3 +/- 16.9 vs. 111.0 +/- 18.9 mg/dl; P = 0.0109). To assess whether these parameters were independently associated with atherosclerosis, a multiple logistic regression was performed, also including other variables which differed between the atherosclerotic group and the control group with P values less than 0.20 (cigarette smoking, arterial hypertension, body mass index, serum HDL-cholesterol, HDL-cholesterol/total cholesterol ratio, serum triglycerides, IgG and IgM). In multivariate analysis only IgA (P = 0.0012), C4 (P = 0.0072), cigarette smoking (P = 0.0141) and serum triglycerides (P = 0.0177) were independently associated with atherosclerosis.(ABSTRACT TRUNCATED AT 250 WORDS)     

Extracellular HIV-1 Tat protein activates phosphatidylinositol 3- and Akt/PKB kinases in CD4+ T lymphoblastoid Jurkat cells

The biological basis for the pleiotropic activity of extracellular human immunodeficiency virus (HIV)-1 Tat protein on lymphoid T cell survival is not well understood. We have here demonstrated that the addition in culture of 0.1–10 nM Tat protein to 36-h serum-starved lymphoblastoid Jurkat T cells rapidly stimulates the catalytic activity of phosphatidylinositol 3-kinase (PI 3-K). The peak of activation was observed 30 min after Tat addition. Extracellular Tat also stimulated the catalytic activity of the Akt/PKB kinase, a major target of PI 3-K lipid products. Pretreatment of serum-starved Jurkat cells with 100 nM wortmannin (WT) or 10 μM LY294002, two unrelated pharmacological inhibitors of PI 3-K, markedly suppressed the catalytic activity of both PI 3-K and Akt/PKB in Jurkat cells. Moreover, at low concentrations (0.1–1 nM), extracellular Tat showed a small but reproducible protection of Jurkat cells from apoptosis induced by serum deprivation (p < 0.05), while the combination of Tat plus 100 nM WT significantly (p < 0.05) increased the percentage of apoptosis with respect to cells left untreated or treated with Tat alone. Taken together, these data suggest that the anti-apoptotic activity of low concentrations of Tat protein on Jurkat cells is mediated by a PI 3-kinase/Akt pathway.     

Immunofluorescent detection of anti-cytoskeleton antibodies using vinblastine-treated mononuclear cells

A reliable and reproducible immunofluorescence method is described for the detection of anti-cytoskeleton antibodies in human sera, based on the use of vinblastine-treated peripheral blood mononuclear cells as substrate. Three immunofluorescence patterns associated with antibodies to microfilaments, intermediate filaments and microtubules are readily identified.     

Auditory brainstem response in premenopausal women taking oral contraceptives

BACKGROUND: The aim of this prospective study was to evaluate the effects of the new monophasic oral contraceptives on the audiological system in premenopausal women. METHODS: The auditory brainstem response (ABR) was measured in 94 women during the follicular, periovular and luteal phases of one menstrual cycle in which ovulation was confirmed using sonography and serum progesterone concentration. The latencies for waves I, III and V were determined, and the inter-peak intervals were calculated for waves I-III, I-V and III-V. All 94 women began taking oral contraceptives: 23 women used 20 microg ethinyl estradiol (EE) plus 150 microg desogestrel, 24 women used 30 microg EE plus 75 microg gestodene, and 47 women used 15 microg EE plus 60 microg gestodene. During the third month of contraceptive intake, each subject was again tested for ABR, as above. RESULTS: The wave latencies and inter-peak intervals showed shorter values during the periovular phase with respect to the luteal phase (P < 0.05), the follicular phase for wave I and for inter-peak interval I-V (P < 0.05) of the menstrual cycle. All of the ABR results in pill users were statistically different from those of the periovular phase (P < 0.05), though similar to those of both the luteal and follicular phases (P = NS). CONCLUSIONS: ABR seems to depend on the variations of ovarian steroids during the menstrual cycle and during oral contraceptive intake.     

Expression of cytoskeleton components in various Epstein-Barr virus infected cell lines

It has been shown that viruses can induce alterations in the content and distribution of cytoskeleton structures, particularly actin microfilaments and microtubules. An immunomorphologic study of the cytoskeleton components of various EBV-infected cell lines with expression of different functions of EBV genome has been performed using antibodies to each of its three major components. Intermediate filaments and microtubules were similarly represented in all examined lymphoblastoid cell lines. The distribution of actin microfilaments, on the contrary, differed significantly from cell line to cell line. It is concluded that the morphologic expression of actin might depend on the expression of EBV genome. Furthermore, some of these cell lines might represent a useful substrate for the identification of anticytoskeleton antibodies, mainly anti-actin antibodies, in human sera.