The road to ruin: the formation of disease‐associated oral biofilms

Oral Diseases (2010) 16 , 729–739 The colonization of oral surfaces by micro‐organisms occurs in a characteristic sequence of stages, each of which is potentially amenable to external intervention. The process begins with the adhesion of bacteria to host receptors on epithelial cells or in the salivary pellicle covering tooth surfaces. Interbacterial cell–cell binding interactions facilitate the attachment of new species and increase the diversity of the adherent microbial population. Microbial growth in oral biofilms is influenced by the exchange of chemical signals, metabolites and toxic products between neighbouring cells. Bacterial cells on tooth surfaces (dental plaque) produce extracellular polymers such as complex carbohydrates and nucleic acids. These large molecules form a protective matrix that contributes to the development of dental caries and, possibly, to periodontitis. The identification of key microbial factors underlying each step in the formation of oral biofilms will provide new opportunities for preventative or therapeutic measures aimed at controlling oral infectious diseases.     

CNS activational responses to staphylococcal enterotoxin B: T-lymphocyte-dependent immune challenge effects on stress-related circuitry

Staphylococcal enterotoxin B (SEB) is a bacterial superantigen that engages the immune system in a T-lymphocyte-dependent manner and induces a cytokine profile distinct from that elicited by the better-studied bacterial pathogen analog, lipopolysaccharide (LPS). Because of reports of SEB recruiting central nervous system (CNS) host defense mechanisms via pathways in common with LPS, we sought to further characterize central systems impacted by this agent. Rats were treated with SEB at doses of 50-5,000 mug/kg, and killed 0.5-6 hours thereafter. SEB injection produced a discrete pattern of Fos induction in brain that peaked at 2-3 hours postinjection and whose strength was dose-related. Induced Fos expression was predominantly subcortical and focused in a set of interconnected central autonomic structures, including aspects of the bed n. of the stria terminalis, central amygdala and lateral parabrachial nuclei; functionally related (and LPS-responsive) cell groups in the n. solitary tract, ventrolateral medulla, and paraventricular hypothalamic n. (PVH) were, by contrast, weakly responsive. SEB also activated cell groups in the limbic forebrain (lateral septal n, medial prefrontal cortex) and hypothalamic GABAergic neurons, which could account for its failure to elicit reliable increases in Fos-ir or corticotropin-releasing factor (CRF) mRNA in the PVH. SEB nevertheless did provoke reliable pituitary-adrenal secretory responses. The identification of subsets of central autonomic and limbic forebrain structures that are sensitive to SEB provides a basis for a systems-level understanding of the physiological and behavioral effects attributed to the superantigen. Core SEB-responsive cell groups exclude a medullary-PVH circuit implicated in pituitary-adrenal responses to LPS.     

Varices of the round ligament mimicking an inguinal hernia – an important differential diagnosis during pregnancy

Pregnancy is a recognised risk factor for the development of inguinal hernias due to an increase in intra-abdominal pressure. Whilst often managed conservatively until after the pregnancy, if the hernia presents acutely as a painful or tender groin lump, urgent or emergency repair may be required. Many clinicians rely heavily on clinical examination alone in order to diagnose the presence of such a hernia. In pregnancy, however, in order to prevent unnecessary surgery, the use of ultrasound has a more important role to play in reaching this diagnosis. We report a cautionary case that highlights the need for ultrasound evaluation of all painful groin lumps in pregnant women prior to considering surgery.     

Undetected chronic obstructive pulmonary disease and asthma in people over 50 years with persistent cough

Background

Chronic obstructive pulmonary disease (COPD) and asthma are underdiagnosed in primary care.

Aim

To determine how often COPD or asthma are present in middle-aged and older patients who consult their GP for persistent cough.

Design of study

A cross-sectional study in 353 patients older than 50 years, visiting their GP for persistent cough and not known to have COPD or asthma.

Setting

General practice in the Netherlands.

Method

All participants underwent extensive diagnostic work-up, including symptoms, signs, spirometry, and body plethysmography. All results were studied by an expert panel to diagnose or exclude COPD and/or asthma. The reproducibility of the panel diagnosis was assessed by calculation of Cohen''s κ statistic in a sample of 41 participants.

Results

Of the 353 participants, 102 (29%, 95% confidence interval [CI] = 24 to 34%) were diagnosed with COPD. In 14 of these 102 participants, both COPD and asthma were diagnosed (4%, 95% CI = 2 to 7%). Asthma (without COPD) was diagnosed in 23 (7%, 95% CI = 4 to 10%) participants. Mean duration of cough was 93 days (median 40 days). The reproducibility of the expert panel was good (Cohen''s κ = 0.90).

Conclusion

In patients aged over 50 years who consult their GP for persistent cough, undetected COPD or asthma is frequently present.     

心梗后患者12周康复锻炼后一次递增负荷运动中VO2、HR、%HRmax、RPP、ST、RPE变化及其相互关系

目的:探讨12周运动心脏康复锻炼对心梗后患者(PMI患者)心脏机能的影响。方法:112名男性PMI患者(均进行了12周运动心脏康复锻炼)进行一次递增负荷运动实验(Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ级负荷跑速分别为1.7、1.7、1.7、2.5、3.5mph;坡度分别为0.5 %、10 %、12 %、14 %,每一级负荷运动3分钟) ,其间记录每级负荷时的VO2、HR、血压和自我用力感觉(RPE) ,计算心率血压乘积(RPP) ,并持续监测12导联心电图(ECG) ,然后对上述指标进行相关分析并建立了用HR和RPE推测VO2和RPP的回归方程。结果:(1)相邻两级负荷间的VO2、HR、RPP、RPE具有显著差异(P<0.01) ;(2)VO2、HR、最大心率百分数( %HRmax)、RPP、ST段水平(ST)和RPE的峰值分别为26.4±7.1ml·kg-1·min-1、126.8±20.3beats·min-1、80.4±12.9 %、209.0±46.3beats·mmHg·100-1、-1.0±0.7mm和14.9±2.1;(3)运动中VO2、HR、%HRmax、RPP、RPE呈高度正相关,它们与ST呈高度负相关(P<0.01或P<0.05) ,建立了用HR和RPE推测VO2和RPP的回归方程。结论:(1)康复锻炼后利用改良Bruce跑台方案进行机能测试有效;(2)12周康复锻炼后,PMI患者进行运动时其强度不宜超过80 %HRmax或RPE不超过15 ;(3)利用本研究建立的预测方程,可在PMI患者康复活动中,根据其心率或RPE变化间接得知其呼吸循环机能的反应和心肌的耗氧状况。