Evaluation of a novel internally controlled real-time PCR assay targeting the 16S rRNA gene for confirmation of Neisseria gonorrhoeae infections.

A novel HybProbe real-time LightCycler PCR assay was developed for confirmation of Neisseria gonorrhoeae in samples positive according to the COBAS AMPLICOR Chlamydia trachomatis/Neisseria gonorrhoeae PCR assay. The new assay amplifies 375 bp of the N. gonorrhoeae 16S rRNA gene and includes an internal amplification control introduced during DNA purification. The assay had 100% specificity because of the high specificity of the HybProbes and primers. Other Neisseria spp. failed to generate positive crossing-point values and melting peaks. The analytical sensitivity for N. gonorrhoeae DNA was 0.5 fg/PCR, corresponding to 0.3 CFU/PCR. Sensitivity was not impaired in the presence of higher DNA concentrations (>or=1000-fold) from Neisseria spp. other than N. gonorrhoeae. The sensitivity was similar to that reported for the COBAS AMPLICOR assay with cervical swab samples. To assess its clinical applicability as a confirmatory test, 38 (2.9%) of 1313 swabs that were positive according to the COBAS AMPLICOR assay were tested using the new in-house assay and the commercially available GenFlow Neisseria test. Twenty-one samples negative according to COBAS AMPLICOR also underwent confirmatory testing. Both confirmatory tests yielded identical results; the 21 negative samples remained negative, and only 11 (28.9%) of the samples positive according to COBAS AMPLICOR were positive after retesting, suggesting a low prevalence (0.84%) of N. gonorrhoeae infection in the study population. These data suggest that the novel real-time PCR assay is an excellent and easy to interpret confirmatory test for the existing COBAS AMPLICOR assay for N. gonorrhoeae.     

CD14lowCD16high: A cytokine-producing monocyte subset which expands during human immunodeficiency virus infection

Infection with the human immunodeficiency virus HIV-1 is associated with the expansion of a CD14^lowCD16^high monocyte subset in peripheral blood. This subset, which represents a minor subpopulation of monocytes in healthy individuals, increases during HIV infection and, in patients with AIDS, may represent up to 40% of the total circulating monocyte cell population. The CD14^lowCD16^high circulating monocytes co-express MAX.1, p150,95 and HLADR which are typical of tissue macrophage markers. These cells also express higher levels of intracellular interleukin (IL)-1α and tumor necrosis factor (TNF)-α than the CD14^highCD16^low monocyte population from the same patients. The CD14^lowCD16^high cells also express low levels of CD35, CD11a and CD4 in common with normal monocytes. When cultured in vitro, monocytes from HIV-seropositive individuals differentiated within a few hours into an elongated fibroblastoid shape characteristic of migratory cells. Our results suggest that the expansion of the CD14^lowCD16^high monocyte subset, which produce high amounts of TNF-α and IL-1α, may participate in the immune dysfunction observed during HIV infection.     

Inhibition of anti-GD3-ganglioside antibody-induced proliferation of human CD8+ T cells by CD16+ natural killer cells

The ganglioside GD3 has been described as a membrane component of human T cells which is involved in T cell growth. In the present study the activating function of GD3 for human CD4⁺ and CD8⁺ T cells was analyzed by five different monoclonal antibodies (mAb) directed against the GD3 molecule. Three mAb U5, Z21 and R24 induced strong proliferation of peripheral blood mononuclear cells and purified CD8⁺ and CD4⁺ T cells of normal donors containing less than 5% CD16⁺ natural killer (NK) cells. In contrast to CD4⁺ T cells, CD8⁺ T cells proliferated only weakly in the presence of 15% CD16⁺ NK cells. The proliferative response of purified CD4⁺ and CD8⁺ T cells (<5% NK cells) correlated with the antibody-dependent induction of integral and soluble interleukin-2 (IL-2) receptors and was reduced to 20% by an anti-IL-2 receptor antibody. Our results show, that the GD3 molecule represents an activation molecule for both CD4⁺ and CD8⁺ T cells and that CD16⁺ NK cells selectively inhibit anti-GD3 antibody-induced proliferation of CD8⁺ T cells.     

Inactivation of the p16 gene by hypermethylation and loss of heterozygosity in adenocarcinoma of the lung

We investigated the aberrant promoter hypermethylation of p16, p15 and p14 genes and loss of heterozygosity (LOH) at 9p21-22 in 48 cases of adenocarcinoma of the lung. The frequencies of hypermethylation of genes were as follows: p16, 25.0%; p15, 22.9%; and p14, 18.8%. The frequency of LOH at chromosome 9p21-22 was 60.9%. The frequency of two-hit inactivation of the p16 gene by hypermethylation and LOH was 21.7%. Two-hit inactivation of the p16 gene showed loss of protein expression and was significantly correlated with tumor size, tumor grade and the Ki-67 labeling index. Hypermethylation of the p16 gene was not significantly correlated with hypermethylation of the p15 and p14 genes, both of which are close to the p16 gene locus, suggesting that hypermethylation of these genes occurs selectivity. In conclusion, biallelic inactivation of the p16 gene by hypermethylation and LOH might cause loss of p16 expression and play an important role in the development of adenocarcinoma of the lung. Therefore, controlling and monitoring for hypermethylation of the p16 gene may be partially useful for treatment and early diagnosis of adenocarcinoma of the lung.     

参杞合剂对小鼠腹水型肝癌细胞株H22细胞周期及凋亡的影响

目的：观察参杞合剂(SQ)在体内、外对小鼠腹水型肝癌细胞株(HcaF16A3)细胞周期及凋亡的影响。方法：用SQ对荷瘤小鼠连续胃饲治疗10d，观察其NK细胞／Mφ的杀伤活性及细胞周期的改变。用流式细胞仪检测SQ对HcaF16A3细胞增殖的抑制作用与诱导凋亡的作用。结果：SQ的抑瘤率为65．68％。流式细胞仪检测发现，SQ可使肿瘤细胞的细胞周期阻滞到S期，并在体外诱导其凋亡。结论：SQ在体内、外均有抑瘤作用，其机制与细胞周期阻滞继而诱发凋亡有关。     

Molecular diagnosis of a vascular prosthesis infection, due to Propionibacterium acnes, by amplification and sequencing of 16S rDNA

We describe a case of indolent vascular prosthesis infection due to Propionibacterium acnes. The microorganism was identified only by amplification and sequencing of 16S rDNA, while standard cultures remained negative. This observation underscores the usefulness of molecular techniques for the diagnosis of infection caused by fastidious microorganisms.     

毒死蜱对小鼠焦虑样行为以及肠道菌群的影响

目的 观察毒死蜱暴露致小鼠焦虑样行为及肠道菌群的影响,并探讨两者之间的关系。方法 30只8周龄雄性C57BL/6J小鼠,随机分为3组:对照组(CTL)、毒死蜱低剂量组(CPF2.5)和毒死蜱高剂量组(CPF5),分别灌胃植物油、毒死蜱2.5 mg/kg bw和毒死蜱5 mg/kg bw,1次/d,连续14 d。采用旷场实验(OFT)和高架十字迷宫实验(EPM)对小鼠焦虑样行为进行检测; 采用16S rDNA测序检测粪便肠道菌群变化; 用LEfSe筛选各组间差异菌群; 采用Spearman分析研究肠道差异菌和焦虑样行为指标之间的相关性。结果 与CTL相比,CPF2.5和CPF5小鼠进入旷场中心次数减少(F=6.404,P=0.042,P=0.002),在开臂的活动路程百分比、开臂停留时间百分比以及进入开臂次数百分比均降低(F=8.525,P=0.002,P=0.002; F=17.486,P<0.001, P<0.001; F=4.751,P=0.023,P=0.010),以上差异均有统计学意义。LEfSe 多级物种差异判别分析结果显示,Dubosiella、Muribaculum、Akkermansia等菌在对照组富集; Odoribacter、PrevotellaceaeUCG_001菌在CPF2.5组富集; Proteobacteria、Rhizobiaceae、Ochrobactrum、Rhizobiales菌在CPF5组富集。Spearman相关分析结果表明,Muribaculum与EPM开臂活动路程百分比和开臂停留时间百分比呈正相关(r=0.506, P=0.012; r=0.455, P=0.025),Odoribacter和EPM开臂停留时间百分比呈负相关(r=-0.486, P=0.016)。结论 毒死蜱暴露后引起的小鼠焦虑样行为改变可能与特定的肠道菌群丰度(Muribaculum和Odoribacter)改变相关。     

Colonic In Vitro Model Assessment of the Prebiotic Potential of Bread Fortified with Polyphenols Rich Olive Fiber

The use of olive pomace could represent an innovative and low-cost strategy to formulate healthier and value-added foods, and bakery products are good candidates for enrichment. In this work, we explored the prebiotic potential of bread enriched with Polyphenol Rich Fiber (PRF), a defatted olive pomace byproduct previously studied in the European Project H2020 EcoProlive. To this aim, after in vitro digestion, the PRF-enriched bread, its standard control, and fructo-oligosaccharides (FOS) underwent distal colonic fermentation using the in vitro colon model MICODE (multi-unit colon gut model). Sampling was done prior, over and after 24 h of fermentation, then metabolomic analysis by Solid Phase Micro Extraction Gas Chromatography Mass Spectrometry (SPME GCMS), 16S-rDNA genomic sequencing of colonic microbiota by MiSeq, and absolute quantification of main bacterial species by qPCR were performed. The results indicated that PRF-enriched bread generated positive effects on the host gut model: (i) surge in eubiosis; (ii) increased abundance of beneficial bacterial groups, such as Bifidobacteriaceae and Lactobacillales; (iii) production of certain bioactive metabolites, such as low organic fatty acids; (iv) reduction in detrimental compounds, such as skatole. Our study not only evidenced the prebiotic role of PRF-enriched bread, thereby paving the road for further use of olive by-products, but also highlighted the potential of the in vitro gut model MICODE in the critical evaluation of functionality of food prototypes as modulators of the gut microbiota.