Pulmonary nodules detected by thoracic computed tomography scan after exposure to asbestos: diagnostic significance

OBJECTIVE

To analyse the relationship between pulmonary nodules detected by radiologists using computed tomography and cumulative exposure to asbestos or asbestos-related pleuro-pulmonary diseases in 5662 asbestos-exposed subjects, and the relationship between pulmonary nodules and thoracic cancer, to determine whether a specific surveillance strategy based on cumulative asbestos exposure should be adopted.

DESIGN

Standardised incidence and mortality ratios (SIR) for lung cancer and pleural mesothelioma were calculated in patients with and without mention of pulmonary nodules and compared using comparative morbidity figures.

RESULTS

A significant excess incidence of primary lung cancer and pleural mesothelioma was observed among subjects presenting with pulmonary nodule(s) (SIR respectively 1.95, 95%CI 1.22-2.95, and 11.88, 95%CI 3.20-30.41). However, there was no significant relationship between pulmonary nodules mentioned by radiologists and cumulative asbestos exposure or between pulmonary nodules and the presence of asbestos-related benign diseases.

CONCLUSIONS

This study confirms the expected excess prevalence of lung cancer in subjects presenting with pulmonary nodules according to the radiologist's report, and shows the absence of relationship between the presence of nodules and level of cumulative asbestos exposure. Our study therefore offers no argument in favour of specific surveillance modalities based on estimated cumulative asbestos exposure.

Antibacterial resistance, genes encoding toxins and genetic background among Staphylococcus aureus isolated from community-acquired skin and soft tissue infections in France: a national prospective survey

The epidemiology of staphylococcal community-acquired skin and soft tissues infections (CA-SSTIs) has changed dramatically. We described prospectively the characteristics of the Staphylococcus aureus isolated from 71 non-teaching French hospitals and implicated in CA-SSTIs: antimicrobial susceptibility (mecA polymerase chain reaction [PCR], disk diffusion method), virulence factor gene (sea, tst, pvl) prevalence and genetic background (agr allele). During November 2006, 235 strains were collected (wound infection: 51%, abscess: 21%, whitlow: 8%, diabetic foot: 7%, furunculosis: 3%). sea, tst and pvl were identified in 22.1, 13.2 and 8.9% strains, respectively. agr allele 1 was the most frequently encountered genetic background, whatever the methicillin susceptibility. Among the 34 methicillin-resistant S. aureus (MRSA, 14.5% of all S. aureus), only one strain (2.9%) harboured pvl (belonging to the European ST80 clone), four (11.8%) tst (belonging to two endemic French clones) and 18 (52.9%) sea gene (mainly the Lyon clone). According to their in vitro activity, pristinamycin or trimethoprim/sulfamethoxazole could be considered as first-choice antibiotics. To date, the international pvl-positive MRSA clones have not spread in France. MRSA strains isolated from putative CA-SSTIs exhibited a genetic and phenotypic background of hospital-acquired (HA) clones. National survey should be continued, in order to monitor the emergence of virulent clones.

A new concept of gentamicin loaded HAP/TCP bone substitute for prophylactic action: in vivo pharmacokinetic study

Despite systemic prophylaxis, infection rates after orthopedic surgery can reach more than 1%. A new HAP/TCP bone substitute loaded with 125 mg of gentamicin was designed for prophylactic use. Its aim was to enhance the efficacy of systemic prophylactic treatments by increasing the local antibiotic concentration. The release rate of gentamicin from the bone substitute was investigated after implantation in the femoral condyle of five sheep. In order to investigate the local and systemic gentamicin concentrations, synovial fluids and blood samples were assessed over a 5-day period. The mean gentamicin concentration peak in blood was 4.2 μg/ml and the mean local concentration in synovial fluids during the first 8 h was 305 μg/ml. After 48 h, the concentrations in blood and synovial fluids were less than 0.5 μg/ml. No remaining gentamicin was detected in bone substitutes explanted after 8 days of implantation. The gentamicin release rate from the bone substitutes assessed corresponds to the recommendations for the prophylactic use of antibiotics: high local concentration but limited in time (less than 48 h) not to select antibiotic-resistant bacterial strains. Our results indicated that this implant should be an effective prophylactic tool in orthopedic surgery in combination with systemic prophylaxis.

Update on the roles of distal airways in asthma

The present review is the summary of an expert workshop that took place in Vence (France) in 2007 on the role of distal airways in asthma. The evidence showing inflammation and remodelling in distal airways, and their possible involvement in asthma control and natural history, was reviewed. The usefulness and limitations of various techniques used for assessing distal airways were also evaluated, including pulmonary function tests and imaging. Finally, the available data studying the benefit of treatment better targeting distal airways in asthma was examined. It was concluded that both proximal and distal airways were involved in asthma and that distal airways were the major determinant of airflow obstruction. Inflammation in distal airways appeared more intense in severe and uncontrolled asthma. Distal airways were poorly attained by conventional aerosol of asthma medications owing to their granulometry, being composed of 3-5 μm particles. Both proximal and distal airways might be targeted either by delivering medications systemically or by aerosol of extra-fine particles. Extra-fine aerosols of long-acting β-agonists, inhaled corticosteroids or inhaled corticosteroid/long-acting β-agonist combinations have been shown in short-term studies to be not inferior to non-extra-fine aerosols of comparators. However, available studies have not yet demonstrated that extra-fine inhaled medications offer increased benefit compared with usual aerosols in asthmatic patients.

Spatio-temporal analysis of infra-specific genetic variations among a Pseudomonas aeruginosa water network hospital population: invasion and selection of clonal complexes

AIMS

To investigate infra-specific spatio-temporal dynamics of a hospital water network Pseudomonas aeruginosa population. To infer the origin of water network isolates and assess their potential health hazard.

METHODS AND RESULTS

168 P. aeruginosa strains were isolated from tap waters and swabs of tap nozzle aerators of a hospital unit, over 2 years, and from rectal swabs and nosocomial infections. Genetic diversity among this collection was assessed by pulsed field gel electrophoresis of SpeI restricted genomic DNA. Virulence gene sets, biofilm properties, and hypochlorite resistance were analysed. Exactly 68% of the water samples and 74% of the tap nozzle aerators harboured P. aeruginosa. The strains were divided into 22 clonal lineages, with one dominant clone shown to have been involved in a nosocomial infection.

CONCLUSIONS

An important turnover among the P. aeruginosa hospital population was observed. Some clonal lineages were found to persist, spread in the unit, and diversify into clonal complexes. Rectal carriage appeared an important source of contamination of the water network.

SIGNIFICANCE AND IMPACT OF THE STUDY

High P. aeruginosa infra-specific population diversity suggested a broad ability in colonizing water networks but persistence analysis indicated a strong selection leading to the emergence of dominant clones.

Clinicopathological study of 13 cases of squamous cell carcinoma complicating hidradenitis suppurativa

BACKGROUND

To the best of our knowledge, only 52 cases of squamous cell carcinoma (SCC) complicating hidradenitis suppurativa (HS) have been reported since 1958. We describe 13 new cases.

METHODS

We propose a clinical and histological analysis of our cases. We include these results in a review of previously reported cases to analyze a total of 65 patients. In our series of 13 cases, we also investigate the presence of human papillomavirus (HPV) in tumor samples, by polymerase chain reaction (PCR) on paraffin-embedded material.

RESULTS

Malignant transformation affects mainly men with a long-term history of genitoanal HS. Although our cases were 7 well-differentiated carcinomas and 6 verrucous carcinomas, lymphatic and visceral metastasis occurred in 2 and 3 cases, respectively. With PCR, we demonstrated presence of HPV in genitoanal tumoral lesions, principally HPV-16.

CONCLUSION

SCC complicating HS evolves poorly, despite a good histological prognosis. Our results sustain the implication of HPV in the malignant transformation of HS.

[Nocardia aroensis and lung infection: first case report in Africa ]

Nocardiosis is a rare disease that is difficult to diagnose. Pulmonary forms are most common in association with a variety of nonspecific symptoms. Up to now isolation of the offending species, i.e., Nocardia aroensis, has been reported only once during the first description in Japan. The purpose of this article is to report the second world case of isolation of the Nocardia aroensis in a 50-year-old immunocompetent African woman.