Lectin histochemistry for detecting cadmium-induced changes in the glycosylation pattern of rat placenta

Cadmium (Cd) is an industrial and environmental pollutant that produces toxic effects on gametogenesis, pre- and post-implantation embryos, and the placenta. Because the effects of acute Cd intoxication on the placenta are not well understood, we investigated changes in its glycosylated components in Cd treated dams at days 4, 7, 10 and 15 of gestation using lectin histochemistry. CdCl₂ was administered to pregnant rats; control animals received sterile normal saline. Placentas were processed for DBA, Con A, SBA, PNA, UEA-I, RCA-I and WGA lectin histochemistry to evaluate changes in the carbohydrate pattern of the placenta that might modify cell interactions and contribute to embryonic alterations. Lectin binding was analyzed in the yolk sac; trophoblast giant cells; trophoblast I, II and III; spongiotrophoblast cells and endovascular trophoblast cells in the chorioallantoic placenta. Our lectin binding patterns showed that Cd caused alteration of SBA and DBA labeling of trophoblast-derived cells, which suggested increased expressions of α and β GalNAc. Cd also caused decreased UEA-1 binding affinity, which indicated fewer α-L-Fuc residues in placentas of Cd treated dams. The nonreactivity in trophoblast I of the control placentas incubated with Con-A contrasted with the labeling in placentas of experimental dams, which indicated increased expression of terminal α-D-Man, and α-D-Glc residues. We found that Cd altered the reactivity of placenta to several lectins, which indicated modification of the glycotype presented by the fetal component of the placenta. We report that Cd exerts a deleterious effect on the glycosylation pattern of the placenta.     

Challenges and Solutions in the Development of Genomic Biomarker Panels: A Systematic Phased Approach

In the post-genome era, high throughput gene expression profiling has been successfully used to develop genomic biomarker panels (GBP) that can be integrated into clinical decision making. The development of GBPs in the context of personalized medicine is a scientifically challenging and resource-intense process. It needs to be accomplished in a systematic phased approach to address biological variation related to a clinical phenotype (e.g. disease etiology, gender, etc.) and minimize technical variation (noise). Here we present the methodological aspects of GBP development based on the experience of the Cardiac Allograft Rejection Gene Expression Observation (CARGO) study, a study that lead to the development of a molecular classifier for rejection screening in heart transplant patients.     

Cheating is not always punished: killer female plants and pollination by deceit in the dwarf palm Chamaerops humilis

Because the interests of mutualists are not perfectly aligned, conflicts between partners often arise, rendering mutualism unstable by allowing the evolution of cheating. The dwarf palm Chamaerops humilis is engaged in a nursery pollination mutualism with a specific weevil Derelomus chamaeropsis. In exchange for pollen dispersal, dwarf palms provide pollinators with food, shelter and egg-laying sites, but pollinators can develop only within male inflorescences. Here we show that weevils lay eggs in female inflorescences but processes associated with fruit development prevent larval development. The cost imposed by developing larvae probably differs between male and female plants, explaining why only females defend their inflorescences. Female palms thus cheat their pollinating weevil, and pollinators are expected to 'punish' (avoid) them. We found no evidence for such punishment: weevils visit female plants and the duration of visits to male and female inflorescences does not differ. Thus mutualists do not always co-operate and cheating may not be necessarily punished.     

Mutant huntingtin activates Nrf2-responsive genes and impairs dopamine synthesis in a PC12 model of Huntington's disease

Background  

Huntington's disease is a progressive autosomal dominant neurodegenerative disorder that is caused by a CAG repeat expansion in the HD or Huntington's disease gene. Although micro array studies on patient and animal tissue provide valuable information, the primary effect of mutant huntingtin will inevitably be masked by secondary processes in advanced stages of the disease. Thus, cell models are instrumental to study early, direct effects of mutant huntingtin. mRNA changes were studied in an inducible PC12 model of Huntington's disease, before and after aggregates became visible, to identify groups of genes that could play a role in the early pathology of Huntington's disease.     

γδ T Cells Are Required for Pulmonary IL-17A Expression after Ozone Exposure in Mice: Role of TNFα

Ozone is an air pollutant that causes pulmonary symptoms. In mice, ozone exposure causes pulmonary injury and increases bronchoalveolar lavage macrophages and neutrophils. We have shown that IL-17A is important in the recruitment of neutrophils after subacute ozone exposure (0.3 ppm for 24–72 h). We hypothesized that γδ T cells are the main producers of IL-17A after subacute ozone. To explore this hypothesis we exposed wildtype mice and mice deficient in γδ T cells (TCRδ^−/−) to ozone or room air. Ozone-induced increases in BAL macrophages and neutrophils were attenuated in TCRδ^−/− mice. Ozone increased the number of γδ T cells in the lungs and increased pulmonary Il17a mRNA expression and the number of IL-17A⁺ CD45⁺ cells in the lungs and these effects were abolished in TCRδ^−/− mice. Ozone-induced increases in factors downstream of IL-17A signaling, including G-CSF, IL-6, IP-10 and KC were also decreased in TCRδ^−/− versus wildtype mice. Neutralization of IL-17A during ozone exposure in wildtype mice mimicked the effects of γδ T cell deficiency. TNFR2 deficiency and etanercept, a TNFα antagonist, also reduced ozone-induced increases in Il17a mRNA, IL-17A⁺ CD45⁺ cells and BAL G-CSF as well as BAL neutrophils. TNFR2 deficient mice also had decreased ozone-induced increases in Ccl20, a chemoattractant for IL-17A⁺ γδ T cells. Il17a mRNA and IL-17A⁺ γδ T cells were also lower in obese Cpe^fat versus lean WT mice exposed to subacute ozone, consistent with the reduced neutrophil recruitment observed in the obese mice. Taken together, our data indicate that pulmonary inflammation induced by subacute ozone requires γδ T cells and TNFα-dependent recruitment of IL-17A⁺ γδ T cells to the lung.     

Thyroid hormone plasmatic levels in rats treated with serotonin in acute and chronic way

Many experiments show that serotonin (5-HT) controls thyroidal function at hypothalamic level, inhibiting the TRH secretion. The majority of experiments are done in an acute way, consisting of a single serotonin dose injected intraperitoneally (ip) or intracerebroventricularly (ic) with the effect registered after a short time (usually 1 h) as in normal environmental conditions similar to the TSH stimulation test, that consists of transfer of the experimental animals from 30°C to 4°C for 30 min, thus inducing stimulation of the hypothalamus-hypophysis-thyroid axis. The aim of the present research was to study the correlation between 5-HT and the thyroidal function, measuring plasmatic thyroid hormone levels in rats ip treated in chronic (injected daily for 10 days with different doses of 5-HT), and in acute way (after 1 h from a single 2.0 mg/kg bw 5-HT dose) in normal environmental conditions to evidence the serotonin site action activity outside the blood-brain barrier. The results of the chronic experiment show an inhibitory effect of 5-HT, on T3 and T4 plasmatic level, only when it is injected at medium doses (0.2 and 0.4 mg/kg bw for T3, and 0.2 for T4), while the results of the acute experiment do not evidence any modification. These results show that in normal environmental conditions the outside 5-HT site action is active only when the 5-HT is injected chronically at defined doses, probably for a down-regulation phenomenon.     

Stent implantation in acute myocardial infarction using a heparin-coated stent: a pilot study as a preamble to a randomized trial comparing balloon angioplasty and stenting

Preliminary experience with primary stenting in myocardial infarction has suggested a greater benefit in clinical outcome than has been obtained with direct balloon angioplasty. However, subacute thrombosis (SAT) remains a limitation for this new mode of therapy. In the BENESTENT II Pilot and main trials, the incidence of SAT with the heparin-coated Palmaz-Schatz stent was only 0.15%. Therefore, as a preamble to a large randomized trial, the feasibility and safety of the use of the Heparin-Coated Palmaz-Schatz trade mark Stent in Acute Myocardial Infarction (AMI) was tested in 101 patients enrolled between April and September 1996 in 18 clinical centres. In 101 stent-eligible AMI patients, as dictated by protocol, a heparin-coated stent was implanted. The primary objectives were to determine the in-hospital incidence of major adverse cardiac events (MACE: death, MI, target lesion revascularization) and bleeding complications, while the secondary objectives were the procedural success rate and the MACE, the restenosis and reocclusion rates at 6.5 months. Stent implantation (n 3 129 stents) was successful in 97 patients of the 101 who were included in this trial. During their hospital stay, two patients died and no patient experienced re-infarction, ischaemia prompting re-PTCA or CABG. Four patients suffered a bleeding complication, three major and one minor, of whom three required surgical repair. At 210 days follow-up, 81% of the patients were event free. At 6.5 months restenosis was documented in 18% of the 88 patients who underwent follow-up angiography, including three total occlusions. The results, both with respect to QCA and the occurrence of MACE, compare favourably with studies using elective stenting in both stable and unstable angina patients. As a result of this pilot study, a large randomized trial comparing direct balloon angioplasty with direct stenting in 900 patients with AMI was initiated in December 1996.