Vitamin D3 inhibits proinflammatory cytokines and nitric oxide production by the EOC13 microglial cell line

In recent years, a neuroimmunomodulatory role for 1,25-dihydroxyvitamine D(3) [1,25(OH)(2)D(3)] has emerged. Microglial cells present a potential target for the effects of this hormone in the brain. This study focuses on the effect of 1,25(OH)(2)D(3) on the expression and production of inflammatory cytokines and nitric oxide (NO) by the EOC13 microglial cell line. The presence of the vitamin D3 receptor in microglia was demonstrated by RT-PCR. 1,25(OH)(2)D(3) inhibited the production of tumor necrosis factor-alpha, interleukin-6, and NO by stimulated microglia in a concentration-related fashion. The production of transforming growth factor-beta1 (TGF-beta1), an anti-inflammatory cytokine, was not modified in the presence of 1,25(OH)(2)D(3), indicating that the effects of 1,25(OH)(2)D(3) may not involve TGF-beta1 regulation. These results show that 1,25(OH)(2)D(3) has direct anti-inflammatory properties on microglia. It further supports the hypothesis that 1,25(OH)(2)D(3) could be involved in the maintenance of the brain homeostasis and may have a therapeutic potential in inflammatory pathologies of the central nervous system.     

抗凝血相关因子抗体检测方法的建立及临床应用

目的抗磷脂抗体综合征(APS)患者血清中是否存在识别纤溶酶、凝血酶和活性蛋白C(APC)的抗磷脂抗体(aPL)。方法分别用凝血酶、纤溶酶和APC包被酶标板,建立抗纤溶酶、抗凝血酶和抗APC抗体的检测方法。结果在40例APS患者和40名正常对照的血清中,前者抗纤溶酶抗体阳性率为42.5%(17/40),抗凝血酶抗体阳性率为35%(14/40),对照组则两者均为阴性,差异有显著性(P<0.01)。但两组样本抗APC抗体检测结果的A值经检验差异无显著性(P>0.05)。结论APS患者的血清中可检测出抗纤溶酶、抗凝血酶和抗APC抗体,其临床意义有待进一步研究。     

Pharmacokinetic interaction between ethinyl estradiol, norethindrone and darunavir with low-dose ritonavir in healthy women

BACKGROUND: An open-label, randomized, crossover study was performed to investigate the effect of multiple doses of darunavir co-administered with low-dose ritonavir (DRV/r) on the steady-state pharmacokinetics of the oral contraceptives ethinyl estradiol (EE) and norethindrone (NE) (commercial name of the combined drug Ortho-Novum 1/35) in 19 HIV-negative healthy women. METHODS: In session 1, participants received 35 microg EE and 1.0 mg NE from days 1 to 21. In session 2, participants received the same oral contraceptive treatment as in session 1 on days 1 to 21 plus DRV/r (600 mg/100 mg twice daily) on days 1 to 14. Pharmacokinetic assessments were performed on day 14 for each session. RESULTS: Steady-state systemic exposure to EE and NE decreased when DRV/r was co-administered, based on the ratio of least square means of the minimum plasma concentration (Cmin), the maximum plasma concentration (Cmax), and the area under the curve (AUC24h) of EE (which decreased by 62%, 32% and 44%, respectively) and NE (which decreased by 30%, 10% and 14%, respectively) compared with administration of EE and NE alone. Five participants discontinued the study due to grade 2 cutaneous events, as required per protocol, during treatment with EE and NE in combination with DRV/r. There were no clinically relevant findings for laboratory and cardiovascular parameters. CONCLUSIONS: The pharmacokinetic interaction observed here is considered to be clinically relevant as EE concentrations are considerably reduced when DRV/r is co-administered with EE and NE. Alternative or additional contraceptive measures should be used when oestrogen-based contraceptives are co-administered with DRV/r.     

Genome-wide patterns of identity-by-descent sharing in the French Canadian founder population

In genetics the ability to accurately describe the familial relationships among a group of individuals can be very useful. Recent statistical tools succeeded in assessing the degree of relatedness up to 6–7 generations with good power using dense genome-wide single-nucleotide polymorphism data to estimate the extent of identity-by-descent (IBD) sharing. It is therefore important to describe genome-wide patterns of IBD sharing for more remote and complex relatedness between individuals, such as that observed in a founder population like Quebec, Canada. Taking advantage of the extended genealogical records of the French Canadian founder population, we first compared different tools to identify regions of IBD in order to best describe genome-wide IBD sharing and its correlation with genealogical characteristics. Results showed that the extent of IBD sharing identified with FastIBD correlates best with relatedness measured using genealogical data. Total length of IBD sharing explained 85% of the genealogical kinship''s variance. In addition, we observed significantly higher sharing in pairs of individuals with at least one inbred ancestor compared with those without any. Furthermore, patterns of IBD sharing and average sharing were different across regional populations, consistent with the settlement history of Quebec. Our results suggest that, as expected, the complex relatedness present in founder populations is reflected in patterns of IBD sharing. Using these patterns, it is thus possible to gain insight on the types of distant relationships in a sample from a founder population like Quebec.     

Lack of intraindividual variation of unbalanced spermatozoa frequencies from a 46,XY,t(9;22)(q21;q11.2) carrier: case report

The meiotic segregation pattern of 83 men carrying a balanced reciprocal translocation between two autosomes has already been published. Nevertheless, the question of intraindividual variations has not been addressed yet. A 32-year-old patient was found to be a carrier of a t(9;22)(q21;q11.2) during the investigations for a couple with infertility for 3 years. Two sperm samples were obtained at more than 3 months interval. Both sperm samples were analyzed in triple FISH with the D9Z1 and LSI BCR/ABL ES translocation probes. The frequency of gametes exhibiting a chromosomal imbalance was 45.32% and 42.1% in samples 1 and 2, respectively, with the unbalanced spermatozoa resulting from adjacent 1, adjacent 2, and 3:1 segregation in decreasing frequencies. No statistically significant difference was found between both segregation profiles. Four studies have analyzed the meiotic segregation pattern of translocations within families; they found similar profiles of meiotic segregation in each family, but not between families. This suggests, along with our results, that meiotic segregation is not a random process. More studies on intraindividual variations are necessary to allow a better understanding of the meiotic behaviour of chromosomal rearrangements and the practical interest of studies of this kind.     

Functional assessment of vascular reactivity after chronic intermittent hypoxia in the rat

We recently developed a model of chronic intermittent hypoxia (CIH) (FiO2 5%, 8 h/day, 35 days) in the rat that was associated with an increased infarction in isolated heart. The aim of the present study was to characterize its functional consequences on vasoreactivity. Aorta and carotid artery were studied using organ bath technique while mesenteric vascular bed was perfused. In the three vascular beds, relaxation to acetylcholine was similar in CIH and control normoxic (NX) rats. Contractions to noradrenaline and angiotensin II were similar between CIH and NX rats. In contrast, contraction to endothelin-1 was increased by 17% (P < 0.05) in carotid artery from CIH rats. Indomethacin pre-treatment reduced by 24% (P < 0.001) contraction to endothelin-1 in carotid artery from CIH rats only. These data suggested that 35-day CIH-exposure induced no change in endothelial function of aorta, carotid artery and mesenteric bed. In contrast, CIH-exposure induced an increased contractile response to endothelin-1 in carotid artery, presumably owing to the release of constrictor cyclooxygenase-derived products.     

Recent insights into the signals that control αβ/γδ-lineage fate

Summary:  During thymopoiesis, two major types of mature T cells are generated that can be distinguished by the clonotypic subunits contained within their T-cell receptor (TCR) complexes: αβ T cells and γδ T cells. Although there is no consensus as to the exact developmental stage where αβ and γδ T-cell lineages diverge, γδ T cells and precursors to the αβ T-cell lineage (bearing the pre-TCR) are thought to be derived from a common CD4⁻CD8⁻ double-negative precursor. The role of the TCR in αβ/γδ lineage commitment has been controversial, in particular whether different TCR isotypes intrinsically favor adoption of the corresponding lineage. Recent evidence supports a signal strength model of lineage commitment, whereby stronger signals promote γδ development and weaker signals promote adoption of the αβ fate, irrespective of the TCR isotype from which the signals originate. Moreover, differences in the amplitude of activation of the extracellular signal-regulated kinase- mitogen-activated protein kinase-early growth response pathway appear to play a critical role. These findings will be placed in context of previous analyses in an effort to more precisely define the signals that control T-lineage fate during thymocyte development.     

Easy and fast detection and genotyping of high-risk human papillomavirus by dedicated DNA microarrays

Persistent cervical high-risk human papillomavirus (HPV) infection is correlated with an increased risk of developing a high-grade cervical intraepithelial lesion. A two-step method was developed for detection and genotyping of high-risk HPV. DNA was firstly amplified by asymmetrical PCR in the presence of Cy3-labelled primers and dUTP. Labelled DNA was then genotyped using DNA microarray hybridization. The current study evaluated the technical efficacy of laboratory-designed HPV DNA microarrays for high-risk HPV genotyping on 57 malignant and non-malignant cervical smears. The approach was evaluated for a broad range of cytological samples: high-grade squamous intraepithelial lesions (HSIL), low-grade squamous intraepithelial lesions (LSIL) and atypical squamous cells of high-grade (ASC-H). High-risk HPV was also detected in six atypical squamous cells of undetermined significance (ASC-US) samples; among them only one cervical specimen was found uninfected, associated with no histological lesion. The HPV oligonucleotide DNA microarray genotyping detected 36 infections with a single high-risk HPV type and 5 multiple infections with several high-risk types. Taken together, these results demonstrate the sensitivity and specificity of the HPV DNA microarray approach. This approach could improve clinical management of patients with cervical cytological abnormalities.     

Porcine reproductive and respiratory syndrome virus modulates apoptosis during replication in alveolar macrophages

Different viruses have evolved strategies that inhibit apoptosis of the host cell early in infection and/or induce apoptosis in the host cell late in infection. In this study, it was investigated if and when porcine reproductive and respiratory syndrome virus (PRRSV) modulates apoptosis in PRRSV-infected macrophages. The PRRSV replication cycle in macrophages was completed within 12 h post-inoculation (hpi). PRRSV-infected macrophages, treated with staurosporine at 4, 5, 6 and 8 hpi, were significantly protected against staurosporine-induced apoptosis, but PRRSV-infected macrophages, treated with staurosporine at 12 hpi, were not. In contrast, starting from 12 hpi, all PRRSV-infected macrophages died by caspase-dependent apoptosis, which culminated in secondary necrosis. Treatment of PRRSV-infected macrophages with Z-Val-DL-Asp-fluoromethylketone indicated that apoptosis late in infection was not essential for efficient virus release. Anti- and pro-apoptotic activities were also observed in PRRSV-infected Marc-145 cells. In conclusion, this study shows that PRRSV stimulates anti-apoptotic pathways in macrophages early in infection and that PRRSV-infected macrophages die by apoptosis late in infection.