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。     

Molecular epidemiology of fluoroquinolone resistance in invasive clinical isolates of Streptococcus pneumoniae in Seville

Introduction

Due to the emergence of drug-resistant pneumococcal isolates, new fluoroquinolones have been recommended for the treatment of pneumococcal infections. The purpose of this study was to establish surveillance, and to conduct molecular characterization, of fluoroquinolone-resistant Streptococcus pneumoniae in Seville.

Method

Norfloxacin-resistant S. pneumoniae isolates were characterized by quinolone resistance-determining region (QRDR) substitutions, reserpine-sensitive efflux, serotype and by pulsed-field gel electrophoresis (PFGE) patterns.

Results

Fourteen isolates (5.1%) showed an MIC > 16 μg/ml to norfloxacin. Eight of 10 adult isolates were susceptible to levofloxacin. The 4 infant isolates with norfloxacin MIC > 16 μg/ml were susceptible to levofloxacin. Seven of these 12 low-level-resistant isolates had mutations in ParC, while mutations both in ParC and GyrA genes were only detected in one of the two high-level-resistant isolates. All the isolates without QRDR substitutions that remained norfloxacin-resistant were positive for reserpine-inhibited efflux. The serotyping and PFGE revealed significant heterogeneity. We obtained 9 different profiles, 3 of which had two isolates each. Two of the isolates with the same pulsotype were from the same patient. The first isolate showed a mutation in the QRDR of ParC, and the second one had an additional GyrA mutation.

Conclusion

In our study a levofloxacin resistance rate of 0.7% was found among invasive isolates. Although resistance level is low, surveillance is necessary, especially to prevent cases of in vivo resistance development as reported.     

mTOR inhibition with rapamycin causes impaired insulin signalling and glucose uptake in human subcutaneous and omental adipocytes

Rapamycin is an immunosuppressive agent used after organ transplantation, but its molecular effects on glucose metabolism needs further evaluation. We explored rapamycin effects on glucose uptake and insulin signalling proteins in adipocytes obtained via subcutaneous (n=62) and omental (n=10) fat biopsies in human donors. At therapeutic concentration (0.01 μM) rapamycin reduced basal and insulin-stimulated glucose uptake by 20-30%, after short-term (15 min) or long-term (20 h) culture of subcutaneous (n=23 and n=10) and omental adipocytes (n=6 and n=7). Rapamycin reduced PKB Ser473 and AS160 Thr642 phosphorylation, and IRS2 protein levels in subcutaneous adipocytes. Additionally, it reduced mTOR-raptor, mTOR-rictor and mTOR-Sin1 interactions, suggesting decreased mTORC1 and mTORC2 formation. Rapamycin also reduced IR Tyr1146 and IRS1 Ser307/Ser616/Ser636 phosphorylation, whereas no effects were observed on the insulin stimulated IRS1-Tyr and TSC2 Thr1462 phosphorylation. This is the first study to show that rapamycin reduces glucose uptake in human adipocytes through impaired insulin signalling and this may contribute to the development of insulin resistance associated with rapamycin therapy.     

S100B and schizophrenia

The research for peripheral biological markers of schizophrenia, although abundant, has been unfruitful. In the last 2 decades, the S100B protein has made its own room in this area of research. S100B is a calcium‐binding protein that has been proposed as a marker of astrocyte activation and brain dysfunction. Research results on S100B concentrations and schizophrenia clinical diagnosis are very consistent; patients with schizophrenia have higher S100B concentrations than healthy controls. The results regarding schizophrenia subtypes and clinical characteristics are not as conclusive. Age of patients, body mass index, illness duration and age at onset have been found to show no correlation, a positive correlation or a negative correlation with S100B levels. With respect to psychopathology, S100B data are inconclusive. Positive, negative and absence of correlation between S100B concentrations and positive and negative psychopathology have been reported. Methodological biases, such as day/night and seasonal variations, the use of anticoagulants to treat biological samples, the type of analytical technique to measure S100B and the different psychopathological scales to measure schizophrenia symptoms, are some of the factors that should be taken into account when researching into this area in order to reduce the variability of the reported results. The clinical implications of S100B changes in schizophrenia remain to be elucidated.     

What are the critical incidents that affect how people cope with being detained under Section 136 of the Mental Health Act (1983, 2007)?

Abstract

Purpose: Section 136 (S136) of the Mental Health Act (1983, 2007) provides legislative powers for police officers to detain those suspected of being ‘mentally disordered’ for a mental health assessment. Despite its increasing use, there is currently little qualitative research exploring detainee’s experiences.

Methodology: Participants recruited from NHS places of safety participated in a semi-structured interview. The novel application of Critical Incident Technique (CIT) within this study enabled the specific identification of critical incidents which mental health service users thought had either helped with, or worsened the S136 detention experience. A wish list of absent factors was also gathered.

Findings: Six categories of helpful critical incidents, seven categories of unhelpful critical incidents and five categories of wish-list items were identified. The importance of authentic relationships underpinned many categories, as well as challenging stigma, considering previous detentions; and receiving practical support.

Originality/value: The outlined study is the first of its kind to utilise CIT methodology to specifically identify critical incidents related to the process of S136 detention. These findings provide specific ways to improve the experience of detention informed directly by those who have been directly subjected to S136.

• Key points

• Take time to invest in meaningful relationships with those who are detained; asking about the individual’s life experience and their perception of its relationship to their current presenting difficulties.

• Identify the service user’s values -what’s important to them, and what gives meaning to their life – and discuss this in relation to what their worries, concerns or wishes may be for treatment.

• Discuss previous experiences of involuntary admission- this can support all parties involved to consider the impact of detention upon the individual, and services.

• Use problem-free discussions to normalise and help de-stigmatise mental health difficulties and support rapport building.

• Provide practical support, such as food, drink and routinely allow those who are detained to gather personal belongings such as a change of clothes or a book.

• Ensure advocacy services are always available and accessible for those who are detained under S136.

• Where possible, avoid the use of restrictive or stigmatising practices in front of the public where possible (e.g. use of handcuffs, police vehicles as transport) to minimise risk of increasing mental health stigma.

     

The Psychometric Properties and Correlates of the Reynolds' Suicide Ideation Questionnaire with Kuwaiti and American Students

In samples of Kuwaiti (n = 460) and American (n = 273) college students, the Reynolds Suicide Ideation Questionnaire (SIQ) proved to have good internal consistency and concurrent validity with measures of anxiety, optimism, pessimism, death obsession, obsession-compulsion, and ego-grasping. The SIQ was factorially complex in both samples, but the eight critical items showed a similar two-factor pattern in both samples. It is important to note that in spite of the great differences between Kuwait and US students and their cultures, the findings were quite similar. By and large, the psychological correlates of the SIQ may have cross-cultural generality.     

Ruthenium Red Colorimetric and Birefringent Staining of Amyloid-β Aggregates in Vitro and in Tg2576 Mice

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