高通量测序在鸟类肠道微生物中的研究进展

鸟类作为分布广泛、种群数量庞大和高度多样化的物种之一,在病原体传播中发挥了重要作用。本文综述了基于高通量测序技术的3种测序策略(16S rDNA测序、宏基因组测序和宏转录组测序)的特点及其在鸟类肠道菌群多样性、抗生素抗性基因和病原微生物发现中的应用,并对未来发展趋势进行了展望。     

Failure of productive infection of Mallards (Anas platyrhynchos) with H16 subtype of avian influenza viruses

Background

Mallard ducks and other waterfowl represent the most important reservoirs of low pathogenic avian influenza viruses (LPAIV). In addition, mallards are the most abundant duck species in Eurasia that migrate over long distances. Despite extended wild bird monitoring studies over the past decade in many Eurasian countries and investigating hundreds of thousands of wild bird samples, no mallard duck was found to be positive for avian influenza virus of subtype H16 in faecal, cloacal or oropharyngeal samples. Just three cases of H16 infections in Anseriformes species were described worldwide. In contrast, H16 viruses have been repeatedly isolated from birds of the Laridae family.

Objective

Here, we tested the hypothesis that mallards are less permissive to infection with H16 viruses.

Methods

Groups of mallard ducks of different age were inoculated via the oculo-nasal-oral route with different infectious doses of an H16N3 AIV.

Results

The ducks did not show any clinical symptoms, and no virus shedding was evident from cloacal and respiratory routes after experimental infection as shown by negative RT-qPCR results. In addition, all serum samples taken on days 8, 21 and 24 post-inoculation were negative by competitive NP-ELISA.

Conclusions

This study provided evidence that mallards are resistant to infection with H16N3 LPAIV.     

Exploring the relationship between cognitive illness representations and poor emotional health and their combined association with diabetes self-care. A systematic review with meta-analysis

Objective

Depression and anxiety are common in diabetes and are associated with lower diabetes self-care adherence. How this occurs is unclear. Our systematic review explored the relationship between cognitive illness representations and poor emotional health and their combined association with diabetes self-care.

Methods

Medline, Psycinfo, EMBASE, and CINAHL were searched from inception to June 2013. Data on associations between cognitive illness representations, poor emotional health, and diabetes self-care were extracted. Random effects meta-analysis was used to test the relationship between cognitive illness representations and poor emotional health. Their combined effect on diabetes self-care was narratively evaluated.

Results

Nine cross-sectional studies were included. Increased timeline cyclical, consequences, and seriousness beliefs were associated with poorer emotional health symptoms. Lower perceived personal control was associated with increased depression and anxiety, but not mixed anxiety and depressive symptoms. Remaining cognitive illness representation domains had mixed statistically significant and non-significant relationships across emotional states or were measured only once. Effect sizes ranged from small to large (r = ± 0.20 to 0.51). Two studies explored the combined effects of cognitions and emotions on diabetes self-care. Both showed that cognitive illness representations have an independent effect on diabetes self-care, but only one study found that depression has an independent effect also.

Conclusions

Associations between cognitive illness representations and poor emotional health were in the expected direction — negative diabetes perceptions were associated with poorer emotional health. Few studies examined the relative effects of cognitions and emotions on diabetes self-care. Longitudinal studies are needed to clarify directional pathways.     

Tamoxifen induces resistance to activated protein C

Introduction

The estrogen antagonist tamoxifen (TAM) increases the thrombotic risk similar to estrogen containing oral contraceptives (OC). In OC users this risk is attributed to alterations of hemostasis resulting in acquired resistance to activated protein C (APC). TAM-induced APC resistance has not been reported yet.

Materials and Methods

Blood samples were collected prospectively from women with breast cancer before (n = 25) and monthly after start of adjuvant TAM treatment (n = 75). APC resistance was evaluated on basis of the effect of APC on the endogenous thrombin generation potential. To detect increased in vivo APC generation APC plasma levels were measured using a highly sensitive oligonucleotide-based enzyme capture assay. Routine hemostasis parameters were measured additionally.

Results

APC sensitivity decreased by 41% (p = 0.001) compared to baseline after one month of TAM application and remained significantly decreased during the study period. Free protein S increased (p = 0.008) while other analyzed procoagulant factors, inhibitors, and activation markers of coagulation decreased or did not change significantly. In five patients the APC concentration increased to non-physiological levels but an overall significant increase of APC was not observed.

Conclusions

This is the first study showing acquired APC resistance under TAM therapy. Acquired APC resistance might explain the increased thrombotic risk during TAM treatment. Observed changes of hemostasis parameters suggest different determinants of TAM-induced APC resistance than in OC-induced APC resistance. The presence of acquired APC resistance in TAM patients warrants further evaluation if these patients may benefit from antithrombotic prophylaxis in the presence of additional thrombotic risk factors.     

Risk factors and clinical profile of thrombotic thrombocytopenic purpura in systemic lupus erythematosus patients. Is this a distinctive clinical entity in the thrombotic microangiopathy spectrum?: A case control study

Introduction

The association of thrombotic thrombocytopenic purpura (TTP) with systemic lupus erythematosus (SLE) is rare. It is associated with high morbidity and mortality. Information about risk factors and clinical outcomes is scant.

Material and Methods

A retrospective case-control study was performed in a referral center in Mexico City between 1994 and 2013. Patients were diagnosed with TTP if they fulfilled the following criteria: microangiopathic haemolytic anaemia, thrombocytopenia, high LDH levels, normal fibrinogen and negative Coombs’ test. Patients with SLE were diagnosed with ≥ 4 ACR criteria. We included three study groups: group A included patients with SLE-associated TTP (TTP/SLE; cases n = 22, TTP events n = 24); patients with non-autoimmune TTP (NA-TTP; cases n = 19, TTP events n = 22) were included in group B and patients with SLE without TTP (n = 48) in group C.

Results

After multivariate analysis, lymphopenia < 1000/mm3 [OR 19.84, p = 0.037], high SLEDAI score three months prior to hospitalisation [OR 1.54, p = 0.028], Hg < 7 g/dL [OR 6.81, p = 0.026], low levels of indirect bilirubin [OR 0.51, p = 0.007], and less severe thrombocytopenia [OR 0.98, p = 0.009] were associated with TTP in SLE patients. Patients with TTP/SLE received increased cumulative steroid dose vs. NA-TTP (p = 0.006) and a higher number of immunosuppressive drugs (p = 0.015). Patients with TTP/SLE had higher survival than NA-TTP (p = 0.033); however, patients hospitalised for TTP/SLE had a higher risk of death than lupus patients hospitalised for other causes

Conclusions

Lymphopenia is an independent risk factor for TTP/SLE. It is likely that patients with TTP/SLE present with less evident clinical features, so the level of suspicion must be higher to avoid delay in treatment.     

Impacts of HIV infection and long-term use of antiretroviral therapy on the prevalence of oral human papilloma virus type 16

J Oral Pathol Med (2012) 41 : 309–314 Background: The objectives of this study were to determine (i) the prevalence and the copy numbers of oral human papilloma virus type 16 (HPV‐16) in HIV‐infected patients compared with non‐HIV controls, and (ii) the effects of antiretroviral therapy (ART) and its duration on the virus. Methods: A cross‐sectional study was carried out in HIV‐infected patients with and without ART and in non‐HIV controls. Saliva samples were collected, and the DNA extracted from those samples was used as a template to detect HPV‐16 E6 and E7 by quantitative polymerase chain reaction. Student’s t‐test and ANOVA test were performed to determine the prevalence rates among groups. Results: Forty‐nine HIV‐infected patients: 37 on ART (age range, 23–54 years; mean, 37 years), 12 not on ART (age range, 20–40 years; mean, 31 years), and 20 non‐HIV controls (age range, 19–53 years; mean, 31 years) were enrolled. The prevalence of oral HPV‐16 infection and the copy numbers of the virus were significantly higher in HIV‐infected patients than in non‐HIV controls when using E6 assay (geometric mean = 10696 vs. 563 copies/10⁵ cells, P < 0.001), but not E7 assay. No significant difference was observed between those who were and were not on ART. Long‐term use of ART did not significantly change the prevalence of oral HPV‐16 infection and the copy numbers of the virus (P = 0.567). Conclusion: We conclude that the prevalence of oral HPV‐16 infection and the copy numbers of the virus are increased by HIV infection. Neither the use of ART nor its duration significantly affected the virus.     

Combined cytoplasmic and membranous EGFR and p53 overexpression is a poor prognostic marker in early stage oral squamous cell carcinoma

J Oral Pathol Med (2012) 41 : 559–567 Objective: Our aim was to evaluate the expression of several molecules that regulate growth, the cell cycle and signalling pathways including EGFR, p53, p16 and p27 in oral squamous cell carcinomas (OSCC). We examined their utility as prognostic markers by relating to clinicopathological characteristics and the clinical outcome. Patients and methods: Using tissue microarray technology, we analysed 67 primary OSCC and examined immunohistochemical expression of EGFR, p53, p16 and p27. Multivariate analysis was conducted to examine their role in survival. Results: Many of the markers were highly expressed in these cancers. Membranous EGFR expression in 95.2%, both membrane and cytoplasm expression in 35%, p53 expression in 61.6%, p27 expression in 89.5% and p16 expression in 27.9% of cases. In the multivariate analysis, independent prognostic influence of a lower overall survival was determined only for advanced tumour stage (P < 0.001), p53 overexpression (P = 0.004), EGFR cytoplasm and membrane co‐expression location (P = 0.002) and p16 reduced expression (P = 0.002). When considering a subgroup of early stage tumours, p53 overexpression (P = 0.028) and combined membranous and cytoplasm EGFR co‐expression (P = 0.039) were indicators of a lower overall survival. For disease‐free survival, in addition to these three factors, the histological grade (P = 0.011) showed independent prognostic values. Conclusion: The independent value of EGFR subcellular location (cytoplasm and membrane) and p53 overexpression in overall survival even in early stages of OSCC suggests that these markers may serve as reliable biological markers to identify high‐risk subgroups and to guide therapy.     

小“S”形深部拉钩在下颌骨髁突矢状骨折复位固定中的应用

25例(30侧)下颌骨髁突囊内矢状骨折患者,均采用小"S"形深部拉钩辅助下复位,用侧壁拉力螺钉行坚固内固定,全部治愈。应用小"S"形深部拉钩可缩短手术时间,复位效果好,可有效避免深部组织损伤,值得推广。     

应用变性梯度凝胶电泳分析牙周基础治疗前后龈下菌群的变化

目的:应用变性梯度凝胶电泳(denaturing gradient gel electrophoresis,DGGE)方法观察比较牙周基础治疗前后龈下菌群微生态的总体变化,为临床诊疗方案的确定提供实验依据。方法:选取6例慢性牙周炎患者,观察牙周基础治疗前和治疗后6周时的临床指标变化,并采集治疗前后同一位点的龈下菌斑,提取总DNA,扩增不同的16S rDNA片段,DGGE分离,硝酸银染色,对图像进行聚类分析,并绘出聚类树形图。结果:所有患者经过治疗后,与基线相比,牙周状况均明显改善。基线和治疗后6周时,2个区间的DNA片段的条带数目无显著差异。通过聚类分析,证实同一患者基线时和基础治疗后6周时的龈下菌群具有较高的相似性,且不同的DNA片段所得到的条带图谱聚类树形图存在类似结果。结论:同一患者在基础治疗后形成的龈下菌群有类似于治疗前水平的趋势。DGGE能够观察龈下菌群的组成变化,适用于分析大量微生物标本的结构改变。