Staying active during Covid-19 crisis: why it would have been important to keep public parks opened

Background

In 2020, the Covid 19 pandemic and associated restrictions, including limited access to public urban green space (UGS), have led to a decrease in the ability of city dwellers to engage in physical activity. In France, more than 52% people reported being physically active in urban parks. Based on the GREENH-City research carried out in cities of the French network of WHO healthy cities, this presentation aims to show that UGS, depending on different drivers, can support a wide variety of physical activities, but also offer multiple other functions that contribute more or less directly to the health of the population.

Methods

A qualitative survey was conducted among users of 3 different parks in each of the 6 selected cities with both observations and semi-directive interviews and a thematic analyzes were performed. Observed activities were classified into 8 groups including physical activity (non-sport, sports). Interview's analysis aimed to describe the reasons for coming and the type of activity made.

Results

186 observations and 591 recorded and unrecorded interviews with individuals or groups were conducted in the 18 parks. 24 types of physical activity have been described as possible uses of UGS. The most important, regardless of UGS location, is children activities in playgrounds. The most common activities are walking (with a social function) and jogging (individual function). Proximity and the accessibility are two reasons for use.

Conclusions

UGS are an open access amenity for physical activities. From a social justice perspective, policy makers should ensure that every neighborhood is sufficiently close to an UGS. In addition to promoting physical activity, UGS also serve an important social function and impact the collective physical and mental health of the population in many other ways (e.g., as environmental risk regulators). Their coping role during crisis for population would worth to be studied further.

Key messages

Proximity and accessibility should shape local policies related to UGS renewal towards more equity. Different typologies of urban parks at the city level can offer multiple functions, including facilitation of physical activity that contribute to the health of the population.

Colonization resistance against multi-drug-resistant bacteria: a narrative review

Colonization resistance by gut microbiota is a fundamental phenomenon in infection prevention and control. Hospitalized patients may be exposed to multi-drug-resistant bacteria when hand hygiene compliance among healthcare workers is not adequate. An additional layer of defence is provided by the healthy gut microbiota, which helps clear the exogenous bacteria and acts as a safety net when hand hygiene procedures are not followed. This narrative review focuses on the role of the gut microbiota in colonization resistance against multi-drug-resistant bacteria, and its implications for infection control. The review discusses the underlying mechanisms of colonization resistance (direct or indirect), the concept of resilience of the gut microbiota, the link between the antimicrobial spectrum and gut dysbiosis, and possible therapeutic strategies. Antimicrobial stewardship is crucial to maximize the effects of colonization resistance. Avoiding unnecessary antimicrobial therapy, shortening the antimicrobial duration as much as possible, and favouring antibiotics with low anti-anaerobe activity may decrease the acquisition and expansion of multi-drug-resistant bacteria. Even after antimicrobial therapy, the resilience of the gut microbiota often occurs spontaneously. Spontaneous resilience explains the existence of a window of opportunity for colonization of multi-drug-resistant bacteria during or just after antimicrobial therapy. Strategies favouring resilience of the gut microbiota, such as high-fibre diets or precision probiotics, should be evaluated.

Who, why, when and how do people use urban green spaces? A study of users from 18 parks in France

Introduction

Urban green spaces impact the individual and collective health of populations. At the city level, they act as regulators of environmental hazards and constitute collective protective factors. At the individual level, they constitute social spaces for encounters and rejuvenation. But, these functions depend on the use made of these green spaces which can be inequitable. This paper presents the results of the analysis of the use of green spaces in the 6 French cities selected in the WHO French Healthy City Network conducted as part of the GREENH-City research project.

Methods

Based on park profiles, a qualitative survey was conducted among users of 3 different parks in each of the 6 selected cities with both observations and semi-directive interviews. Thematic analyzes were performed. Observed activities were classified into 8 groups (supervised educational, food, activities i.e. calm, commercial, artistic and cultural, physical non-sport, sports) and related to a specific use (professional/ personal, individual/ collective, authorized/ not and conflictual/ not). The uses described by the individuals interviewed were classified into 4 categories: attendance, utility, opinions and activities.

Results

186 observations and 591 recorded and unrecorded interviews with individuals or groups were conducted in the 18 parks. Overall, calm activities are dominant. However, activities and uses differ between cities and within the city depending on the nature of the parks (ancient, new..), their management, their location (more or less central, located in a deprived area or not) and people expectations.

Conclusions

Park uses are only partially dependent on amenities within the park. The nature of the park itself, its geographical location and its landscape characteristics seem to be decisive for the uses observed. These data are essential to inform public decision-makers and guide the creation and development of green spaces in cities in a vision of social justice.

Key messages

Urban green spaces can improve population health but their uses may be inequitable. Study of population use of urban green spaces may help to shape local policies towards more equity.

Intervention research partnerships: enablers for activating health in all policies approach?

Introduction

Action on the determinants of health and equity involves the participation of all sectors, including non-health sectors. Understanding the opportunities and constraints to engage in the complex issue of health inequalities requires opening the black box of policy making. It also requires close interaction between field actors and researchers. This paper will aim to analyze the modalities of collaboration between researchers and field actors in the service of knowledge sharing, within the GREENH-City project.

Methods

The GREENH-City project was built in an interdisciplinary and intersectoral manner and involves close collaboration with the WHO French Healthy Cities Network (FHCN). Its objective is to characterize the most promising health interventions in all policies at the city level to promote equity through green space policies. Based on the knowledge sharing model and the theory of diffusion of innovations, we will analyze how this research allows initiating collaborations between the different municipal sectors on health issues.

Results

The intervention nature of the project seems to help the dissemination of collaborations, particularly between health services and green space services within the cities of the FHCN. The analysis, using theoretical models, of the body of empirical data collected from cities will make it possible to identify the levers and collateral effects activated by the research project.

Discussion

The GREENH-City project was built on the basis of an interventional research framework. This choice was made precisely because of the interaction it induces between researchers and practice environments. Initial empirical results suggest that it promotes the dissemination of knowledge, a necessary first step in the evolution of practices. Indeed, the effective appropriation of research results can only be assessed in the long term and must take into account the contextual elements specific to each FHCN involved in the research.

Key messages

Implementation of interventional research helps to engage fields collaborations. Health in all policies may be supported by a research project at the local level.

Assessment of long-term exposure to airborne dioxin and cadmium concentrations in the Lyon metropolitan area (France)

Identifying the long-term effects of airborne pollutants requires the computation of the spatial and temporal variability of their concentration in air to estimate the exposure of the population. To estimate exposure levels of individuals in a breast cancer case control study nested in a national prospective cohort, we determine here the differential impact of a variety of cadmium and dioxin sources on urban air over a large urban area and over a period of almost 20years. To that end, we couple an emission model, to estimate dioxin and cadmium atmospheric annual releases, with an urban dispersion model in order to compute pollutant concentration fields at a fine temporal (1h) and spatial (25m) resolution. The reliability of the modelling chain is compared to two types of measurement: i) localized industrial emissions and ii) dioxin and cadmium air monitoring data (from 2007 to 2008), collected at a fixed station, placed in the city centre, as well as at three mobile short-term dioxin monitoring stations, located in the suburbs (the latter providing dioxin data, only). Comparisons between measured and estimated emissions show non-negligible difference, with a correlations for dioxin (r_s=0.42) and cadmium (r_s=0.41). Despite this, mean values between estimated emissions and emission measurements are close to each other, in particular for cadmium. Weekly average modelled concentrations show an overall good agreement with weekly average measured concentrations in spring and summer but are generally lower than monitored data in winter due to peak concentrations from diffuse sources representing an important proportion of emissions in 2007/2008. The model provides better results for cadmium than for dioxin. Despite the relevant errors in the model predictions, the model meets the validation criteria, defined by Chang and Hanna for an urban dispersion model. Simulation scenarios of air pollutant concentrations, reconstructed over the last 20years, show the effects of the variability of the pollutant sources over time with decreasing levels of dioxin and cadmium concentrations in air. This is primarily due to the reduction in localized industrial releases, which results in a general trend of homogenization of the exposure of the population. The model further allows us to dissociate the contribution of different types of pollutant sources on the population exposure. The impact on local concentrations due to industrial emissions, which were originally responsible for the major impact on air quality, is shown to drop over the years by 99% and 92% for dioxin and cadmium, respectively. Today, the major contributions are due to diffuse miscellaneous sources in the case of dioxin and to traffic-related emissions for cadmium. Average modelled concentrations at the study subjects' residential locations range from 10.2 to 82.1fg-TEQ/m³ for dioxin and 0.10 to 1.6ng/m³ for cadmium and are comparable with data from the literature. The study results will be essential to increase the accuracy of the assessment of long-term airborne dioxin and cadmium exposure and improve the results of epidemiological studies.

Prognostic role of histological regression in primary cutaneous melanoma: a systematic review and meta-analysis

The prognostic significance of histological regression in primary melanoma has been debated for many years. We aim to review the evidence to see how histological regression may affect prognosis. A systematic review was performed by searching in MEDLINE, Scopus and the Cochrane Library from 1 January 1966 to 1 August 2015. All studies reporting hazard ratios or data on survival and histological regression were included. Primary random-effects meta-analyses were used to summarize outcome measures. Heterogeneity was assessed using the χ² -test and I² -statistic. To assess the potential bias of small studies we used funnel plots and the Begg and Mazumdar adjusted rank correlation method. Summaries of survival outcomes were measured as hazard ratios or relative risk of death at 5 years according to the presence of histological regression of primary melanoma. In total, 183 articles were reviewed out of 1876 retrieved. Ten studies comprising 8557 patients were included. Patients with histological regression had a lower relative risk of death (0·77, 95% confidence interval 0·61-0·97) than those without. Examination of the funnel plot did not provide evidence of publication bias. The results showed that histological regression is a protective factor for survival.

Vaccinal status of healthcare students in Lille

INTRODUCTION

Vaccine recommendations are the same for healthcare students than for other health care workers. The aim of this study was to describe mandatory and recommended vaccinal coverage and evaluate the benefit of systematic monitoring by a medical team in the Lille Medical School.

POPULATION AND METHODS

A survey was performed from June 2011 to August 2011 on all students in the first year of Health Care Studies. The personal immunization record was considered as evidence of vaccination. The reference vaccinal schedule was the one recommended by the French High Council for Public Health in 2011.

RESULTS

We analyzed the personal immunization records of 553 students. The vaccination coverage was 96.7% (535) for DTP, 74.7% (413) for hepatitis B, and 92.2% (510) of the students had a tuberculin test result. Concerning the recommended vaccinations, 78% (431) were covered for measles, and 78.9% (436) had a history of either chickenpox or its immunization. About 72.7% (402) of students were vaccinated for Haemophilus influenzae and Bordetella pertussis. Respectively, 24.2% (134) and 81% (448) had previously been vaccinated for Neisseria meningitis and tuberculosis. The monitoring of students allowed improving hepatitis B vaccination coverage by 22.28% (123). The student's vaccinal coverage was still inadequate for hepatitis B and measles. The systematic monitoring allowed significantly improving vaccinal coverage for hepatitis B.

Unraveling the mystery of the disorder of keratinization: the path of syndromic ichthyoses

In the last few years the progresses in molecular analysis allow better definitions of ichthyoses and lead to the necessity of a new classification and a review of nomenclature of inherited ichthyoses. So, in 2007 the First Consensus Conference on Ichthyoses was performed. We present here a short review of the new classification of syndromic ichthyoses together with clinical and molecular features.

A green and bio-inspired process to afford durable anti-biofilm properties to stainless steel

A bio-inspired durable anti-biofilm coating was developed for industrial stainless steel (SS) surfaces. Two polymers inspired from the adhesive and cross-linking properties of mussels were designed and assembled from aqueous solutions onto SS surfaces to afford durable coatings. Trypsin, a commercially available broad spectrum serine protease, was grafted as the final active layer of the coating. Its proteolytic activity after long immersion periods was demonstrated against several substrata, viz. a synthetic molecule, N-α-benzoyl-DL-arginine-p-nitroanilide hydrochloride (BAPNA), a protein, FTC-casein, and Gram-positive biofilm forming bacterium Staphylococcus epidermidis.

Biomolecule-based antibacterial coating on a stainless steel surface: multilayer film build-up optimization and stability study

The goal of this paper was to establish the durability profile of antibacterial multilayer thin films under storage and usage conditions. Thin films were built on stainless steel (SS) by means of a layer-by-layer process alternating a negatively charged polyelectrolyte, polyacrylic acid, with a cationic antibacterial peptide, nisin. SS coupons coated with the antibacterial film were challenged under environmental and usage conditions likely to be encountered in real-world applications. The change in antibacterial activity elicited by the challenge was used as an indicator of multilayer film resistance. Antibacterial SS samples could be stored for several weeks at 4°C in ambient air and antibacterial films were resistant to dipping and mild wiping in water and neutral detergent. The multilayer coating showed some weaknesses, however, that need to be addressed.

Selective expression of two types of 28S rRNA paralogous genes in the chaetognath Spadella cephaloptera

Significant intra-individual variation in the sequences of the ribosomal RNA (rRNA) genes is highly unusual in animal genomes; however, two classes of both 18S and 28S rRNA gene sequences have been detected in chaetognaths, a small phylum of marine invertebrates. One species, Spadella cephaloptera Busch, 1851, is well-suited to the methods of in situ analysis of gene expression, since it is totally transparent. To test our hypothesis of a possible functional division of the two classes of genes, we carried out in situ hybridization. Our results indicated that 28S class II genes are expressed intensively in the oocytes of chaetognaths. In contrast, hybridization using an heterologous probe of 28S class I genes revealed only a single and relatively weak signal in a distinct area of intestinal cells. Our results suggest that the S. cephaloptera genome contains at least three different types of rRNA 28S genes; however, those which are expressed during housekeeping conditions could not be detected in our experiments.

Comparison of chaetognath mitochondrial genomes and phylogenetical implications

Two complete mitochondrial genomes (mtDNAs) of chaetognaths, Spadella cephaloptera and Paraspadella gotoi, have been recently published. These genomes are highly unusual. They are the smallest metazoan mtDNAs so far known; atp6 and atp8 genes are missing; lastly, our reanalysis has evidenced that, contrarily to what has been previously published for one sequence, both contain a unique transfer RNA (tRNA(Met)) evidencing that both have the same gene content. Indeed, even if the gene order seems very different, two gene blocks are conserved. In addition, comparison of gene arrangement suggests phylogenetical relationships between chaetognaths and some lophotrochozoa like annelids and molluscs.

Alternative peptide-fusion proteins generated by out-of-frame mutations, just upstream ORFs or elongations in mutants of human hepatitis B viruses

By various means including out-of-frame mutations, just upstream ORFs and elongations, additional peptide fusions could be generated by mutants of Human Hepatitis B Virus (HBV). Numerous frameshift mutations inducing long alternative open reading frames have been evidenced in all HBV genes. Interestingly, these mutants are frequently detected in severe liver diseases, but seldom in asymptomatic carriers. The high level of conservation of some of these sequences in spite of the fact that they could be generated by different types of mutations, as their presence in mutants found on various continents, suggest that these mutations could play a role. These mutants could combine two advantages, that related to the loss of a part of a wild-type protein and that related to the putative advantage conferred by the additional sequences. In addition, in numerous Asian genomes (more than 300 to date) pre-X or pre-pre-S regions were found just upstream to, respectively, the X and the pre-S1 genes. These two regions are translated with their respective genes in frame and recent studies have evidenced the transactivating role of the corresponding proteins. With some exceptions, these regions are genotype- and serotype-specific (C/adr). In addition, these mutants have been found principally in patients with severe hepatitis diseases, for example, hepatocarcinoma in more than one third of the cases. As additional sequences generated by HBV variants may be relevant for viral life cycle, persistence and pathogenesis, further investigations are necessary to give a clearer picture of the subject.

Multiple sclerosis and hepatitis B vaccination: Could minute contamination of the vaccine by partial Hepatitis B virus polymerase play a role through molecular mimicry?

Reports of multiple sclerosis developing after hepatitis B vaccination have led to the concern that this vaccine might be a cause of multiple sclerosis in previously healthy subjects. Some articles evidenced that minor Hepatitis B virus (HBV) polymerase proteins could be produced by alternative transcriptional or translational strategies. Their detection is very difficult because they are in minute concentration and probably enzymatically inactive, however, it was shown that they could be exposed on the outside of the virus particles and also be immunogenic. In addition, HBV polymerase shares significant amino acid similarities with the human myelin basic protein. We hypothesise that some of the apparent adverse reactions to the vaccine could be due to a process called of molecular mimicry, the HBV polymerase, which could be a contaminant in the recombinant or plasma-derived vaccines, could act as autoantigens and induce autoimmune demyelinating diseases such as multiple sclerosis.

Factors associated with early atrial fibrillation after ablation of common atrial flutter. A single centre prospective study

BACKGROUND

The occurrence of early atrial fibrillation (< or = 6 months) after ablation of common atrial flutter is of clinical significance. Variables predicting this evolution in ablated patients without a previous atrial fibrillation history have not been fully investigated.

OBJECTIVES

The aim of the present study was: (1) to identify predictive factors of early atrial fibrillation (< or = 6 months) in the overall population following atrial flutter catheter ablation; (2) to identify predictive variables of early atrial fibrillation following (< or = 6 months) atrial flutter catheter ablation within a subgroup of patients without documented prior atrial fibrillation.

METHODS

This study prospectively included 96 consecutive patients (age 65 +/- 13 years; 18 women) over a 12-month period. Their counterclockwise flutter was ablated by radiofrequency, by the same operator, with an 8-mm-tip catheter. Clinical, electrophysiological and echocardiographic data were collected and 27 variables were retained for analysis: age; gender; type of atrial flutter (permanent vs paroxysmal); symptom duration (months +/- SD); pre-ablation history of atrial fibrillation; structural heart disease; left ventricular ejection fraction (%); left atrial size (mm); cava--tricuspid isthmus dimension; septal isthmus dimension; systolic pulmonary pressure > or < or = 30 mmHg; right atrial area; left atrial area; isthmus block; number of radiofrequency applications (+/- SD); antiarrhythmic drugs at discharge; left ventricular diastolic diameter; left ventricular systolic diameter; left ventricular telediastolic volume; left ventricular telesystolic volume; A-wave velocity (cm . s(-1)); E-wave velocity (cm . s(-1)); E/A; isovolumetric relaxation time; E-wave deceleration time; significant mitral regurgitation and flutter cycle length (ms).

RESULTS

Of the 96 consecutive ablated patients, early atrial fibrillation was documented in 16 patients (17%). Atrial fibrillation occurred 30 +/- 46 days (range 1 to 171 days) after ablation. Univariate analysis associated an early occurrence of atrial fibrillation with: atrial fibrillation history, left ventricular ejection fraction, left atrial size, left ventricular telesystolic volume, A-wave velocity, significant mitral regurgitation and flutter cycle length. Multivariate analysis using a Cox model found that the only independent predictors of early atrial fibrillation were left ventricular ejection fraction and pre-ablation history of atrial fibrillation. In the subgroup without prior atrial fibrillation history (n=63; 66%), the only independent predictor of early atrial fibrillation was the presence of a significant mitral regurgitation.

CONCLUSIONS

In a subgroup of patients without atrial fibrillation history, 8% of patients revealed an early atrial fibrillation. Mitral regurgitation is a strong predictive factor of early atrial fibrillation occurrence with 80% sensitivity, 78% specificity and 98% negative predictive value. These data should be considered in post-ablation management.

[Skeletal muscle metastases from non small cell lung]

We report a case of metastatic spread to skeletal muscle in a patient with an inoperable NSCLC complaining of a painful swelling of the right thigh. The treatment included muscle resection, radiotherapy to the thigh and chemotherapy, and resulted in complete pain relief There was no local recurrence, but the patient developed multiple systemic metastases and died 11 months after the muscle resection. Skeletal muscles metastases from lung cancer are rare and although indicative of a poor prognosis, local aggressive treatment may be worthwhile.

Toll-like receptor-4 is expressed by macrophages in murine and human lipid-rich atherosclerotic plaques and upregulated by oxidized LDL

BACKGROUND

Inflammation is implicated in atherogenesis and plaque disruption. Toll-like receptor 2 (TLR-2) and TLR-4, a human homologue of drosophila Toll, play an important role in the innate and inflammatory signaling responses to microbial agents. To investigate a potential role of these receptors in atherosclerosis, we assessed the expression of TLR-2 and TLR-4 in murine and human atherosclerotic plaques.

METHODS AND RESULTS

Aortic root lesions of high-fat diet-fed apoE-deficient mice (n=5) and human coronary atherosclerotic plaques (n=9) obtained at autopsy were examined for TLR-4 and TLR-2 expression by immunohistochemistry. Aortic atherosclerotic lesions in all apoE-deficient mice expressed TLR-4, whereas aortic tissue obtained from control C57BL/6J mice showed no TLR-4 expression. All 5 lipid-rich human plaques expressed TRL-4, whereas the 4 fibrous plaques and 4 normal human arteries showed no or minimal expression. Serial sections and double immunostaining showed TLR-4 colocalizing with macrophages both in murine atherosclerotic lesions and at the shoulder region of human coronary artery plaques. In contrast to TLR-4, none of the plaques expressed TLR-2. Furthermore, basal TLR-4 mRNA expression by human monocyte-derived macrophages was upregulated by ox-LDL in vitro.

CONCLUSIONS

Our study demonstrates that TLR-4 is preferentially expressed by macrophages in murine and human lipid-rich atherosclerotic lesions, where it may play a role to enhance and sustain the innate immune and inflammatory responses. Moreover, upregulation of TLR-4 in macrophages by oxidized LDL suggests that TLR-4 may provide a potential pathophysiological link between lipids and infection/inflammation and atherosclerosis.

Abnormal function of astroglia lacking Abr and Bcr RacGAPs

Experiments in cultured cells have implicated the molecular switch Rac in a wide variety of cellular functions. Here we demonstrate that the simultaneous disruption of two negative regulators of Rac, Abr and Bcr, in mice leads to specific abnormalities in postnatal cerebellar development. Mutants exhibit granule cell ectopia concomitant with foliation defects. We provide evidence that this phenotype is causally related to functional and structural abnormalities of glial cells. Bergmann glial processes are abnormal and GFAP-positive astroglia were aberrantly present on the pial surface. Older Abr;Bcr-deficient mice show spontaneous mid-brain glial hypertrophy, which can further be markedly enhanced by kainic acid. Double null mutant astroglia are hyper-responsive to stimulation with epidermal growth factor and lipopolysaccharide and exhibit constitutively increased phosphorylation of p38 mitogen-activated protein kinase, which is regulated by Rac. These combined data demonstrate a prominent role for Abr and Bcr in the regulation of glial cell morphology and reactivity, and consequently in granule cell migration during postnatal cerebellar development in mammals.

Long-term follow-up of contralateral lobe in patients hemithyroidectomized for solitary follicular adenoma

OBJECTIVES

Since there are no available conclusive studies on the long-term evolution of remnant thyroid tissue after hemithyroidectomy in patients who undergo surgery for solitary follicular adenomas, we searched for such cases in our records to elucidate this issue.

DESIGN

Search criteria were as follows: (i) presence of a single palpable thyroid nodule with the remainder of the gland normal on palpation; (ii) clinically euthyroid status at the time of surgery; (iii) histological diagnosis of nodule as follicular adenoma; (iv) a hemithyroidectomy operation, sparing the contralateral lobe; (v) normal macroscopic aspect of the contralateral lobe at the time of surgery; and (vi) at least 4 years of postoperative follow-up.

PATIENTS

Only 47 female cases were found to meet above criteria, with a mean age of 45.9 years (range: 23-79) at the time of surgery and a mean follow-up of 7.2 years (range: 4-32). Besides evaluating the presence or absence of antithyroid antibodies and the extranodular histology of tissue removed during surgery, a preoperative TRH test also allowed patients to be classified into two groups: normal extranodular thyroid (NET) (n = 32) and abnormal extranodular thyroid (AET) (n = 15).

RESULTS

Eleven of the 15 patients with AET had thyroid autoimmunity, with or without overt histological thyroiditis, and the remaining four had subclinical hypothyroidism with negative antithyroid antibody titres. In the entire study population, only 28 patients received treatment with L-T4 immediately after surgery, none of whom had any alterations in the contralateral lobe. However, six of the nineteen patients not treated with T4 (31.6%) developed overt abnormalities in the contralateral lobe, including the only three with AET who had not received L-T4 treatment. The remaining three were two patients with NET, who showed postoperative TSH hyper-responsiveness to TRH (peak TSH > 25 mU/l), and one who developed a new follicular adenoma 32 years later. To date, none of the patients with NET, who had a normal TRH test after surgery, have developed any kind of alterations in the contralateral lobe, even those who received no L-T4 prophylactic treatment.

CONCLUSIONS

The findings of this study suggest that: (i) there is a higher risk of follicular adenomas developing in a gland affected by thyroid autoimmunity than in a previously normal gland; (ii) L-T4 therapy may prevent the formation of new nodules or the development of goitre in the contralateral lobe; and (iii) in the absence of prophylactic treatment after surgery, the contralateral lobe of subjects with thyroid autoimmunity and/or previous subclinical hypothyroidism develops morphological abnormalities.

Decreased expression of Toll-like receptor-4 and MD-2 correlates with intestinal epithelial cell protection against dysregulated proinflammatory gene expression in response to bacterial lipopolysaccharide

The lumenal surface of the colonic epithelium is continually exposed to Gram-negative commensal bacteria and LPS. Recognition of LPS by Toll-like receptor (TLR)-4 results in proinflammatory gene expression in diverse cell types. Normally, however, commensal bacteria and their components do not elicit an inflammatory response from intestinal epithelial cells (IEC). The aim of this study is to understand the molecular mechanisms by which IEC limit chronic activation in the presence of LPS. Three IEC lines (Caco-2, T84, HT-29) were tested for their ability to activate an NF-kappaB reporter gene in response to purified, protein-free LPS. No IEC line responded to LPS, whereas human dermal microvessel endothelial cells (HMEC) did respond to LPS. IEC responded vigorously to IL-1beta in this assay, demonstrating that the IL-1 receptor signaling pathway shared by TLRs was intact. To determine the reason for LPS hyporesponsiveness in IEC, we examined the expression of TLR4 and MD-2, a critical coreceptor for TLR4 signaling. IEC expressed low levels of TLR4 compared with HMEC and none expressed MD-2. To determine whether the low level of TLR4 expression or absent MD-2 was responsible for the LPS signaling defect in IEC, the TLR4 or MD-2 gene was transiently expressed in IEC lines. Transient transfection of either gene individually was not sufficient to restore LPS signaling, but cotransfection of TLR4 and MD-2 in IEC led to synergistic activation of NF-kappaB and IL-8 reporter genes in response to LPS. We conclude that IEC limit dysregulated LPS signaling by down-regulating expression of MD-2 and TLR4. The remainder of the intracellular LPS signaling pathway is functionally intact.

Clinical characteristics, aetiological factors and long-term prognosis of myocardial infarction with an absolutely normal coronary angiogram; a 3-year follow-up study of 91 patients

OBJECTIVES

The purpose of this study was to evaluate the clinical outcome of a large cohort of patients who suffered an acute myocardial infarction with absolutely normal epicardial coronary arteries at the post-myocardial infarction coronary angiogram. The aetiological and prognostic factors in this population were also analysed.

BACKGROUND

Few data exist concerning the outcome, and aetiological and prognostic factors, of patients with myocardial infarction and angiographically absolutely normal coronary arteries.

METHODS

Ninety-one patients (34 females/57 males; mean age 50+/-13 years, range 24--78 years) admitted with an acute myocardial infarction had absolutely normal coronary arteries at the angiogram performed 6.2+/-4 days (range 1--15 days) after the myocardial infarction, defined by smooth contours and no focal reduction (NC). Of the 91 NC patients, 71 were evaluated prospectively, alongside a systematic search of all aetiological factors reported in the literature. The NC patients were matched for age, sex, and the same period of myocardial infarction onset with a group of 91 patients with coronary artery stenosis (>50% diameter stenosis) at the angiogram performed 7.3+/-4 days (range 1--15 days) after the myocardial infarction (SC).

RESULTS

The percent of smokers was similar between the two groups; higher prevalence rates of coronary heart disease family history, obesity, hypertension, hypercholesterolaemia and diabetes mellitus were found in SC (P=0.043 to 0.0001). In NC, coronary spasm was found in 15.5%, congenital coagulation disorders in 12.8%, collagen tissue disorders in 2.2%, embolization in 2.2%, and oral contraceptive use in 1.1%. Left ventricular ejection fraction at hospital discharge was higher in NC (60%+/-13%) than in SC (55%+/-13%, P=0.04). The mean follow-up was 35 months (range 1--100 months). Kaplan-Meier event-free survival, with the combined end-point defined as death, reinfarction, heart failure and stroke was 75% in NC vs 50% in SC (P<0.0001). Survival rate was 94.5% in NC compared to 92% in SC (ns). Univariate predictors of events in NC were left ventricular ejection fraction (P=0.03), age (P=0.02), diabetes (P=0.01), and smoking (P=0.03). Using Cox multivariate analysis, independent predictors of long-term outcome in NC patients were left ventricular ejection fraction (P=0.003) and diabetes (P=0.004).

CONCLUSION

Aetiological factors, predominantly coronary spasm and inherited coagulation disorder, can be detected in only one third of the patients with myocardial infarction and absolutely normal coronary angiograms despite a systematic search in a prospective population. Mortality rates are similar but morbidity is lower in myocardial infarction patients with absolutely normal coronary angiography compared with those with coronary artery stenosis. The only two independent factors predictive of poor outcome in myocardial infarction patients with normal coronary arteries are left ventricular function and diabetes.

Cooperation of Toll-like receptor 2 and 6 for cellular activation by soluble tuberculosis factor and Borrelia burgdorferi outer surface protein A lipoprotein: role of Toll-interacting protein and IL-1 receptor signaling molecules in Toll-like receptor 2 signaling

Toll-like receptor 2 (TLR2) and TLR4 play important roles in innate immune responses to various microbial agents. We have previously shown that human dermal endothelial cells (HMEC) express TLR4, but very little TLR2, and respond to LPS, but not to Mycobacterium tuberculosis 19-kDa lipoprotein, unless transfected with TLR2. Here we report that HMEC are unresponsive to several additional biologically relevant TLR2 ligands, including, phenol-soluble modulin (PSM), a complex of three small secreted polypeptides from the skin commensal Staphylococcus epidermidis, soluble tuberculosis factor (STF), and Borrelia burgdorferi outer surface protein A lipoprotein (OspA-L). Expression of TLR2 renders HMEC responsive to all these ligands. We further characterized the signaling pathway in response to STF, OspA-L, and PSM in TLR2-transfected HMEC. The TLR2 signaling pathway for NF-kappaB trans-activation shares the IL-1R signaling molecules. Dominant negative constructs of TLR2 or TLR6 inhibit the responses of STF and OspA-L as well as PSM in TLR2-transfected HMEC, supporting the concept of functional cooperation between TLR2 and TLR6 for all these TLR2 ligands. Moreover, we show that Toll-interacting protein (Tollip) coimmunoprecipitates with TLR2 and TLR4 using HEK 293 cells, and overexpression of Tollip inhibits NF-kappaB activation in response to TLR2 and TLR4 signaling. Collectively, these findings suggest that there is functional interaction between TLR2 and TLR6 in the cellular response to STF and OspA-L in addition to S. epidermidis (PSM) Ags, and that engagement of TLR2 triggers a signaling cascade, which shares the IL-1R signaling molecules, similar to the TLR4-LPS signaling cascade. Our data also suggest that Tollip may be an important constituent of both the TLR2 and TLR4 signaling pathways.

Bacterial lipopolysaccharide activates HIV long terminal repeat through Toll-like receptor 4

In HIV-infected patients, concurrent infections with bacteria and viruses are known to induce HIV replication as assessed by increases in plasma HIV RNA levels. In the present study, we determined the cell surface receptor and molecular mechanisms of enterobacterial LPS-induced HIV transcription. Human dermal microvessel endothelial cells (HMEC) were transfected with an HIV-long terminal repeat (LTR)-luciferase construct and subsequently stimulated with purified bacterial LPS. Our studies demonstrate that human Toll-like receptor 4 (TLR4) mediates LPS-induced NF-kappaB and HIV-LTR activation in HMEC through IL-1 signaling molecules, namely myeloid differentiation protein, IL-1R-associated kinase, TNFR-associated factor, and NF-kappaB-inducing kinase. Cotransfection of HMEC with HIV-LTR-luciferase and TLR4 cDNA from LPS-hyporesponsive C3H/HeJ mice abrogates LPS-induced HIV transcription as does the use of dominant-negative mutants of the IL-1 signaling molecules. Transfection of HMEC with an HIV-LTR-mutant that lacks the NF-kappaB binding site or pretreatment of cells with chemical inhibitors of the NF-kappaB pathway also blocked LPS-induced HIV-LTR transactivation. These data support the conclusion that TLR4 mediates enterobacterial LPS-induced HIV transcription via IL-1 signaling molecules and NF-kappaB activation plays an important role in HIV-LTR transactivation.

Bacterial lipopolysaccharide and IFN-gamma induce Toll-like receptor 2 and Toll-like receptor 4 expression in human endothelial cells: role of NF-kappa B activation

Toll-like receptor (TLR) 4 has been identified as the primary receptor for enteric LPS, whereas TLR2 has been implicated as the receptor for Gram-positive and fungal cell wall components and for bacterial, mycobacterial, and spirochetal lipoproteins. Vascular endothelial cell (EC) activation or injury by microbial cell wall components such as LPS is of critical importance in the development of sepsis and septic shock. We have previously shown that EC express predominantly TLR4, and have very little TLR2. These cells respond vigorously to LPS via TLR4, but are unresponsive to lipoproteins and other TLR2 ligands. Here we show that LPS, TNF-alpha, or IFN-gamma induce TLR2 expression in both human dermal microvessel EC and HUVEC. Furthermore, LPS and IFN-gamma act synergistically to induce TLR2 expression in EC, and LPS-induced TLR2 expression is NF-kappaB dependent. LPS and IFN-gamma also up-regulate TLR4 mRNA expression in EC. These data indicate that TLR2 and TLR4 expression in ECs is regulated by inflammatory molecules such as LPS, TNF-alpha, or IFN-gamma. TLR2 and TLR4 molecules may render EC responsive to TLR2 ligands and may help to explain the synergy between LPS and lipoproteins, and between LPS and IFN-gamma, in inducing shock associated with Gram-negative sepsis.

Surgical treatment of active and sequelar forms of pulmonary tuberculosis

BACKGROUND

The incidence of tuberculosis has risen since 1990, and in some countries, the resistant forms are becoming more and more frequent. Surgical treatment is once again needed to manage these problems. The purpose of this study was to analyze the indications and results of resection, which we performed for pulmonary tuberculosis.

METHODS

From 1980 to 1997, 477 patients were operated on for thoracic or intrathoracic tuberculosis in Laennec Hospital, Paris (259 suffered lung diseases). There were 165 women and 94 men, aged 25 to 86 years (mean 46 years), from Europe (n = 148), North Africa (n = 65), Subsaharian Africa (n = 34), Asia (n = 7), and the West Indies (n = 5). This population was reviewed concerning the lung tuberculosis (sequelae or active lesions), the indications of lung resection, the type of resections performed, and the results at 1, 6, and 12 months.

RESULTS

Active lesions were present in 97 cases and sequelae in 162. Surgery was performed for a therapeutic purpose in 104 patients with sequelae, and in 10 patients with active tuberculosis (pneumonectomy, n = 19; pleuropneumonectomy, n = 19; lobectomy, n = 54; and segmentectomy, n = 22). Surgery was performed for a diagnostic purpose in 54 patients with sequelae, and in 87 patients with active lesions (lobectomy, n = 32; segmentectomy, n = 19; wedge resection, n = 94, of which 11 performed by video-assisted thoracoscopy since 1991). One patient died after pleuropneumonectomy. We observed 25 complications: empyema, n = 7; hemothorax, n = 2; prolonged air leaks, n = 14; and pneumopathy, n = 2. All patients with active lesions subsequently were given antitubercular drugs. Follow-up was 100% at 1 month, 57% (n = 92) and 77% (n = 75) at 6 months for patients with sequelae and for patients with active lesions, respectively. All were asymptomatic with a normal chest roentgenogram. The number of operations for active lesions is increasing over the years, while it is decreasing for sequelar lesions.

CONCLUSIONS

In our department, surgery is being performed more frequently to make a diagnosis in cases of active tuberculosis, and to treat complicated lesions in case of sequelae. Lung resection for active tuberculosis evolving under treatment or for drug resistance was rare. However, our study confirms the good results commonly obtained by surgery and supports the idea that surgery may help eradicate tuberculosis when social and economic circumstances render its medical management difficult or hazardous.

[Malignant mediastinal lymph node tumors with unknown primary cancers]

PURPOSE

Malignant mediastinal lymph nodes with unknown primary tumor is a rare occurrence. The purpose of this study is to specify some characteristics of the patients presenting with this disease and to define an adequate therapeutic approach.

MATERIAL AND METHODS

Between 1985 and 1997, we have operated on 54 patients with isolated non-small cell malignancy to mediastinal lymph nodes. Forty-nine patients underwent surgical biopsy of the mediastinal mass, generally followed by radiation therapy and/or chemotherapy. A mediastinal lymph node resection was performed in 5 patients.

RESULTS

Five patients were lost to follow-up (9.3%). The 5-year survival rate and the median survival were 12.4 +/- 5% and 7 months respectively. Four of the 7 patients who were still alive after follow-ups ranging from 10 to 68 months had undergone a lymph node resection. During the follow-up, a primary tumor was discovered in only 5 patients (11.4%).

CONCLUSIONS

Patients with isolated malignant lymph nodes of the mediastinum have a poor prognosis. In order to improve their survival, we recommend a more aggressive therapeutic approach comprising a chemotherapy and a mediastinal lymph node resection, associated in some cases with a lung resection. Radiation therapy of the mediastinum can be administered, principally in case of incomplete resection.

Safe and effective placement of two bipolar silicone leads in the cephalic vein using a hydrophilic guidewire and a split introducer

The cephalic vein (CV) is preferable to the subclavian vein for implanting permanent pacing leads because of fewer complications. Unfortunately, this access is unusable in a substantial number of patients. This prospective study evaluates a technique to increase CV access for the placement of two silicone bipolar leads used in DDD pulse generator implants. A standard cephalic cutdown was performed under local anesthesia and a hydrophilic guidewire (HGW) threaded in the CV. The first (ventricular) bipolar lead was then introduced and positioned. When possible, introduction of the second (atrial) lead followed the same direct access. A failed introduction led to a modified procedure (MP) relying on a "split" introducer (8-9 Fr Plastimed) advanced with a circular motion over the HGW, then removal of the dilator, removal of the HGW, insertion of the pacing lead into the sheath with placement in the right atrium, followed by sheath withdrawal. Over an 18-month period, 90 consecutive patients had DDD pacemakers implanted. The CV was accessible in 76 (84.5%) of 90 patients and the direct introduction of the ventricular lead was obtained in 74 (97.4%) of these. Atrialization proceeded as follows: direct access CV in 14 (18%) of 76 patients, MP access in 54 (71%) of 76 patients, and MP failure in 8 (11%) of 76 patients. Overall, this approach allowed cephalic dual insertion in 68 (89%) of 76 patients. In conclusion, the modified procedure presented in this study allows a dual catheterization with bipolar leads in 89% of patients when a CV is available. This significantly improves the success rate for dual bipolar lead implants in this configuration.

Bacterial lipopolysaccharide activates NF-kappaB through toll-like receptor 4 (TLR-4) in cultured human dermal endothelial cells. Differential expression of TLR-4 and TLR-2 in endothelial cells

A missense mutation in the cytoplasmic domain of the Toll-like receptor-4 (TLR-4) has been identified as the defect responsible for lipopolysaccharide (LPS) hyporesponsiveness in C3H/HeJ mice. TLR-4 and TLR-2 have recently been implicated in LPS signaling in studies where these receptors were overexpressed in LPS non-responsive 293 human embryonic kidney cells. However, the signaling role of TLR-4 or TLR-2 in human cells with natural LPS response remains largely undefined. Here we show that human dermal microvessel endothelial cells (HMEC) and human umbilical vein endothelial cells express predominantly TLR-4 but very weak TLR-2 and respond vigorously to LPS but not to Mycobacterium tuberculosis 19-kDa lipoprotein. Transient transfection of non-signaling mutant forms of TLR-4 and anti-TLR-4 monoclonal antibody inhibited LPS-induced NF-kappaB activation in HMEC, while a monoclonal antibody against TLR-2 was ineffective. In contrast to LPS responsiveness, the ability of HMEC to respond to 19-kDa lipoprotein correlated with the expression of TLR-2. Transfection of TLR-2 into HMEC conferred responsiveness to 19-kDa lipoprotein. These data indicate that TLR-4 is the LPS signaling receptor in HMEC and that human endothelial cells (EC) express predominantly TLR-4 and weak TLR-2, which may explain why they do not respond to 19-kDa lipoprotein. The differential expression of TLRs on human EC may have important implications in the participation of vascular EC in innate immune defense mechanisms against various infectious pathogens, which may use different TLRs to signal.