Secondary bacterial infection in plasma endotoxin levels and the acute-phase response of mice infected with Trypanosoma brucei brucei.

Murine Trypanosoma brucei brucei infection leads to elevated plasma endotoxin-like activity levels not related to parasitaemia levels accompanied by the development of acute-phase response and increased plasma levels of serum amyloid P (SAP) and haptoglobin (Hp). To determine the source of the endotoxin-like activity and role of secondary bacterial infection in the pathogenesis of trypanosomosis, infected mice were treated with the antibiotic ciprofloxacin. Plasma endotoxin-like activity levels, irrespective of treatment, were elevated three- to fourfold, beginning 7 days after infection. Plasma protein concentrations increased markedly following infection from 7 days after infection (DAI). Peak Hp and SAP concentrations in ciprofloxacin-treated and -untreated infected mice were attained 7 and 14 DAI, respectively. Thereafter, both protein levels gradually declined until the end of the experiment, but Hp levels for non-treated mice declined up to 21 DAI and thereafter significantly increased on 28 and 35 DAI. Whole-trypanosome lysate and the membrane-enriched fraction demonstrated endotoxin-like activity, with the former having higher levels. The results suggest that the endotoxin-like activity in trypanosome fractions and plasma of infected mice is due to the trypanosome. Further elevation of haptoglobin during the late stages of infection in non-treated mice suggests the involvement of secondary bacterial infection.

Estrogen, heat shock proteins, and NFkappaB in human vascular endothelium.

BACKGROUND: We hypothesized that estrogen would increase HSP72 in human coronary artery endothelial cells (HCAEC), and that these would be more sensitive to estrogen than our previous observations in myocytes. METHODS AND RESULTS: HCAEC were treated with 17beta-estradiol or tamoxifen, ranging from physiological to pharmacological(1 nM to 10 micromol/L) for either 24 hours (early) or 7 days (chronic). HSP expression was assessed by Western blots. Both early and chronic 17beta-estradiol and tamoxifen increased HSP72. Electromobility shift assays (EMSA) showed activation of HSF-1 with early, but not chronic, 17beta-estradiol. 17beta-Estradiol activated NFkappaB within 10 minutes, and the ER-alpha selective inhibitor, ICI 182 780, abolished this effect. Transcription factor decoys containing the heat shock element blocked HSP72 induction. Estrogen pretreatment decreased lactate dehydrogenase release with hypoxia. This protective effect persisted despite blockade of HSF-1 by decoys. However, an NF-kappaB decoy prevented the increase in HSP72 and abolished the estrogen-associated protection during hypoxia. CONCLUSIONS: 17beta-Estradiol upregulates HSP72 early and chronically via different mechanisms in HCAEC, and provides cytoprotection during hypoxia, independent of HSP72 induction. NF-kappaB mediates the early increase in HSP72, suggesting that estrogen activates NF-kappaB via a nongenomic, receptor-dependent mechanism, and this leads to activation of HSF-1. Activation of NF-kappaB was critical for estrogen-associated protection. Further studies are needed to elucidate the involved signaling pathways. We hypothesized that estrogen would increase HSP72 in human coronary artery endothelial cells (HCAEC). Both early and chronic treatment increased HSP72. EMSA showed activation of HSF-1 with early, but not chronic, 17beta-estradiol. Transcription factor decoys blocked estrogen-related HSP72 induction. Estrogen decreased LDH release with hypoxia. An NF-kappaB decoy blocked the HSP72 increase and estrogen-associated protection.

Reproduction in the vervet monkey (Cercopithecus aethiops): endometrial oestrogen and progestin receptor dynamics during normal and prolonged menstrual cycles.

Sixteen individually caged adult female vervet monkeys (Cercopithecus aethiops), whose reproductive parameters had been studied for 5 years, were hysterectomized/ovariectomized during three reproductive states; i.e. the late follicular (15.4 +/- 4.7 (S.D.) days) and luteal (27.8 +/- 4.7 days) phases of the normal cycle (20-50 days), and during prolonged intermenstrual intervals (PII; 99.0 +/- 2.5 days since the previous menses). These latter animals showed characteristics of both follicular and luteal phases; i.e. their ovaries contained both corpora lutea and large antral follicles and systemic oestradiol and progesterone concentrations were raised. Analysis of cytoplasmic oestrogen and progestin receptors (CER and CPR) revealed that endometrium during PII had CER levels of 0.58 +/- 0.07 pmol/mg protein, similar to those of the follicular phase (0.60 +/- 0.12); CPR levels (1.20 +/- 0.87) were not different from those of the luteal phase (1.05 +/- 0.45). The ratio of CPR to CER during the luteal phase was about tenfold higher than that of the follicular phase. Levels during PII were intermediate between the two phases. Under receptor-activating conditions, the DNA-binding components of the PII cytoplasmic fraction underwent over 40% loss while those present during both phases of the normal cycle doubled. The hormone-binding sites at all times remained intact indicating that the DNA and hormone-binding sites are distinct on both CER and CPR. Less than 50% interaction of CER/CPR with DNA-cellulose was obtained, indicating the presence of only limited quantities of cytoplasmic activating factors which may be a prerequisite for receptor binding to the genome. During PII, factors which deactivate DNA-binding sites may also have been induced. Extensive accumulation of nuclear oestrogen receptor was evident in PII endometrium with 80% being salt-resistant. This level is higher than that in the follicular and luteal phases (37 and 52% respectively). These data, suggesting a possible aberration of receptor activation in vitro and receptor processing in vivo, may be indicative of endometrial dysfunction during PII. This could lead to a delay in menstruation.