P311Cardiac damage induced by long term and intensive endurance exercise training in senior athletes: a cardiac magnetic resonance and exercise echocardiography analysis

Background

Moderate intensity regular physical activity is a mainstay of cardiovascular prevention. However, it is under debate whether the cumulative effects of intensive endurance exercise induce chronic cardiac damage. It has been proposed that long-term endurance exercise may be associated with myocardial fibrosis detected by late gadolinium-enhancement (LGE) cardiac magnetic resonance (CMR), and/or with right ventricle contractile dysfunction, creating a potential substrate for ventricular arrythmia, but these aspects are not constantly found across studies. Extracellular volume (ECV) determined by CMR, circulating cardiac biomarkers, and longitudinal global 2D strain (LGS) assessed by cardiac echography are relevant tools to explore these potential adverse effects of exercise in senior athletes.

Purpose

To assess the presence of myocardial fibrosis detected by CMR (LGE and ECV) and biomarkers, and to evaluate ventricles function with LGS, in endurance senior competitive athletes.

Methods

Thirty-three asymptomatic endurance senior athletes (47±6 years old, 9,6±1,7 h of training per week for 26±6 years), were compared to 18 sedentary controls (49±7 years old). They underwent a CMR protocol including morphological and late gadolinium-enhancement (LGE) analysis, T1 mapping and calculation of ECV using a 1.5 T MRI scanner. A maximal exercise transthoracic echography with LGS analysis was performed. Cardiac biomarkers (N terminal pro brain natriuretic peptide, high-sensitivity troponin T and plasma markers of collagen biosynthesis and degradation procollagen type I N terminal propeptide and procollagen type III NT propeptide) were also analysed.

Results

Athletes had higher left (84,0±20,8 vs 67,62±12,4 ml/m2; p=0,00593) and right (41,3±9,5 vs 32,9±6,0 ml/m2; p=0,00228) ventricular volumes, higher total biventricular mass (109,61±14,18 vs 98,66±16,25 g/m2; p=0,02038), and higher stroke volume (50,7±12,6 vs 40,1±9,2 ml/m2; p=0,00441) assessed by CMR versus controls. Native T1 (left ventricle: 938±21 vs 940±34 ms; p=0,8098 - right ventricle: 1027±53 vs 1026±114 ms; p=0,92983) and ECV (21,5±1,6 vs 22,0±2,2%; p=0,40868) were not significantly different in athletes compared with controls. LGE was not found in athletes. Peak exercise LGS values were higher in athletes for left (23,19±2,86 vs 20,82±2,05%; p=0,00335) and right (29,25±3,47 vs 26,48±3,22%; p=0,00777) ventricles, compared with control. The levels of cardiac biomarkers were normal in all subjects.

Conclusion

Athletes showed signs of physiological cardiac remodelling, consistent with previous descriptions of athlete's heart. Despite this important remodelling, there was no evidence of myocardial fibrosis or exercise left or right ventricular dysfunction in athletes. Our results are not supporting the hypothesis of deleterious cardiac effects induced by long term and intensive endurance exercise training.

[Role of surgery in the management of pulmonary parasitosis]

Pulmonary parasitosis is scarcely encountered in France, and its diagnosis is quite difficult. If numerous parasites can be responsible for respiratory symptoms, only few of them can develop in the lung parenchyma and lead to complications necessitating a surgical treatment. The most common example is the hydatic disease of the lung. The authors review the biological cycles, clinical forms, diagnostic and treatment principles of those main lung parasites, which deserve surgical consideration.

Clinical characteristics of the smooth tubercle bacilli 'Mycobacterium canettii' infection suggest the existence of an environmental reservoir

Over a 3-year follow-up, 30 out of the 318 unique Mycobacterium tuberculosis complex isolates recovered in the Republic of Djibouti had a smooth-type morphology and were Niacine-negative, the characteristics of 'Mycobacterium canettii' strains. Unlike M. tuberculosis, 'M. canettii' grew on nutrient-poor media at 30°C, and possessed characteristic lipids. They were isolated from respiratory and extra-respiratory sites from patients with typical forms of tuberculosis. Most cases resolved with antibiotic therapy but in two human immunodeficiency virus-positive patients 'M. canettii' infection led to septicaemia and death. No cases of human-to-human transmission were observed. The proportion of tuberculosis cases caused by 'M. canettii' was higher among French patients than among Djiboutian patients. Patients with 'M. canettii' were significantly younger than those with tuberculosis caused by other M. tuberculosis complex strains. Smooth tubercle bacilli could be misidentified as non-tuberculous mycobacteria and appear to be limited to the Horn of Africa. Their characteristics are consistent with the existence of non-human sources of infection.

Highly structured genetic diversity of the Mycobacterium tuberculosis population in Djibouti

Djibouti is an East African country with a high tuberculosis incidence. This study was conducted over a 2-month period in Djibouti, during which 62 consecutive patients with pulmonary tuberculosis (TB) were included. Genetic characterization of Mycobacterium tuberculosis, using mycobacterial interspersed repetitive-unit variable-number tandem-repeat typing and spoligotyping, was performed. The genetic and phylogenetic analysis revealed only three major families (Central Asian, East African Indian and T). The high diversity and linkage disequilibrium within each family suggest a long period of clonal evolution. A Bayesian approach shows that the phylogenetic structure observed in our sample of 62 isolates is very likely to be representative of the phylogenetic structure of the M. tuberculosis population in the total number of TB cases.

Étude des populations staphylococciques hospitalières: apport des techniques récentes de biologie moléculaire

OBJECTIVES

To determinate the origin of acquired S. aureus among hospitalised patients and to evaluate the transmission of strains between health care workers and hopistalised patients.

METHODS

The method chosen is a prospective study in risky clinical yards. Nasal swabing of patients and health care workers has been done to isolate bacterial samples. Caracterisation and comparaison of bacterial strains have been made using their antibiotic resistance profil and a recent molecular genotyping technic named MLVA (Multi Locus Variable Number of Tandem Repeat). It has never been used in such context.

RESULTS

One hundred and fifty-seven strains have been isolated. They have been compared while realizing 1900 PCR and agar gel electrophoresis in 10 days. 15 clones were identified. One of them is mainly represented among patient's nasal carriage and acquired strains. As far as antibiotype and agr type are concerned, it is similar to hospital-acquired clone described in Europe with other technics (MRSA, Gentamicine-S agr 1). This clone appears to be also transmitted between health care workers and patients.

CONCLUSION

Although it exists, we can't appreciate the intensity of this transmission. These results don't allow us to proceed to a systematic screening for nasal carriage among our health care workers. This study shows that MLVA could be a reliable molecular typing method, which could be used in every day practice. In our experience, it is as performing as PFGE, more didactic, faster and easier.

[Cutaneous tuberculosis overview]

Cutaneous tuberculosis is now uncommon in industrial countries despite the rising incidence of extrapulmonary tuberculosis in areas with high prevalence of HIV infection. Nevertheless it is still important to know the multiple clinical manifestations of cutaneous tuberculosis and to be aware of new laboratory diagnostic methods such as polymerization chain reaction gene amplification.

[Chiroptera and zoonosis: an emerging problem on all five continents]

Zoonosis is the cause of the vast majority of emerging diseases. Bats that occupy the second place in the mammal class play an important role. Whether they belong to the microchiroptera suborder or to the megachiroptera suborder, bats on all five continents have been implicated in transmission of numerous pathogens including not only viruses such as Lyssavirus (e.g. rabies), Hepanivirus (e.g. Hendra and Nipah virus) and recently coronavirus (e.g. SARS-like coronavirus and Ebola virus) but also fungus such as histoplasmosis. By modifying environmental conditions and encroaching on their biotope, human intervention has probably contributed to the introduction of chiropteras into an epidemiologic chain in which they previously had no place, thus promoting the emergence of new pathogens.

[Overview of endemic treponematoses]

Endemic treponematoses including yaws, bejel, pinta are distinguished from venereal syphilis on the basis of epidemiological characteristics and clinical manifestations. They cannot be differentiated by morphological and serological methods. A few minor genetic differences have been identified among the subspecies (Treponema pallidum sp. pallidum, pertenue, endemicum, carateum). Although penicillin therapy is effective, these infectious diseases have yet to be eliminated.

[Rapid immunochromatographic tests for detection of malaria: principles and strategies for use]

Malaria is a parasitological emergency requiring safe quick accurate diagnosis so that appropriate therapy can be implemented. A number of rapid diagnostic tests based on detection of HRP2 Ag, enzymes, LDH or aldolase are now available. However the use of these tests is restricted to trained, experienced staff in special situations. The purpose of this report is to describe the different tests on the market and clarify the limitations for their use.

First identification of the causative agent of visceral leishmaniasis in Djibouti: Leishmania donovani

The first identification of the Leishmania species responsible for visceral leishmaniasis in Djibouti is described. Four strains, obtained from three autochthonous cases, were identified by starch-gel electrophoresis and iso-enzyme analysis of 15 enzymatic systems. The strains were found to belong to two newly recognized zymodemes of L. donovani: MON-268 and MON-287.

Évaluation de la qualité de réalisation des tests de concordance ultime au lit du patient

As far as transfusions accidents are concerned, immunological causes are frequent. Pretransfusion Bedside Compatibility Tests (PBCT) are the last chance to avoid them. However low data are disponible on the quality their realisation is achieved. The aim of the study is to evaluate the quality level of achievement of these tests, in HIA Laveran Hospital (Marseille Armees, France). During 13 months, from november 2001 to december 2002, we systematically analysed PBCT after use (analysis rate 91%). Three kinds of errors have been noticed: Technical errors, understanding errors and both. Overall mistake rate was 10.4% (1632 tests analysed). In the same time, a complementary formation was dispensed to users responsible of misfits. This formation was successful, decreasing the overall mistake rate from 22.8% (november 2001) to 10.7% (december 2002). This study is an evidence of the importance to evaluate achievement quality of PBCT and shows how efficient can be simple correction methods.

[Clinical overview of New World tegumentary leishmaniasis]

This richly illustrated article (80 color photographs) based on the authors' experience in French Guyana documents the clinical diversity of American tegumentary leishmaniasis. Main highlights include the often outstanding aspect of lesions, the high frequency of forms not associated with ulceration or scab formation that must be recognized to achieve diagnosis in travellers returning from endemic zones, and the special prognosis of clinical forms associated with intradermic, lymphatic or hematogenous spread. The article also reviews an original diagnostic method based on culture of cutaneous biopsy specimens on specific nutrient mediums that provides isolates in a high percentage of cases (80%) and thus allows identification of offending parasite.

[Management of American cutaneous leishmaniasis. Outcome apropos of 326 cases treated with high-dose pentamidine isethionate]

The purpose of this retrospective analysis was to evaluate the outcome of pentamidine isethionate treatment (4 mg/kg of Pentamidine by the intramuscular route on Days 1 and 3) of cutaneous leishmaniasis in 326 cases that occurred during an outbreak among French military personnel in French Guyana from 1998 to 1999. A great difference was found between the 205 patients treated in French Guyana (series G) and 32 patients treated at the Laveran Military Hospital in Marseille, France (series L). Failure rate, i.e. 25% in series L versus 5% in series G, was significantly correlated with the delay to treatment which was much longer in series L. Extensive rhabdomyolysis was observed in all cases tested: this side-effect has not been reported. Based on these findings and a review of the literature on pentamidine isethionate, the authors recommend prompt treatment using lower doses. Other treatment alternatives for American cutaneous leishmaniasis are also presented including two of the latest developments in the field, i.e., oral treatment using miltefosine and topical treatment using agents such as paromomycine.

[A cholera epidemic in Dijibouti (May 2000-January 2001)]

The purpose of this report is to describe a cholera outbreak that occurred in the Republic of Djibouti from May 2000 to January 2001. Because the Somalian index cases involved were identified, this outbreak can be used as a model for imported epidemics. Development of the disease in the Djibouti City is promoted by a combination of poor living conditions and inadequate water supply. Unlike in previous epidemics in Djibouti, bacteriological study demonstrated the emergence of Vibrio cholerae strains presenting antibiotic resistance similar to that observed in Somalia. At the only facility available for cholera treatment in the country, 1920 patients were admitted and 36(1.9%) died. An epidemiological study of these patients demonstrated that females accounted for most cases in the 15-to-44-year age group (p < 0.0001) whereas males accounted for most cases in the age groups ranging from 0 to 1 year (p = 0.003) and 5 to 14 years (p = 0.002). These findings suggest that the mode of contamination and access to care vary according to sex and age.

[Epidemiologic surveillance of cutaneous leishmaniasis in Guiana. Summary of military data collected over 10 years]

This report describes the results of epidemiological surveillance of cutaneous leishmaniasis in French military personnel in French Guiana. Data was collected regarding microscopic diagnosis, clinical manifestations, and lesion location as well as compliance with vector control measures. Year-to-year variations in the incidence in the general population have been attributed to changes in climatic conditions. Monitoring incidence and density curves, correlation of findings with local epidemiological data, and analysis of the most recent epidemic in 1998/99 (326 cases, attack rate 3.2% men years) highlight the importance of behavioral factors. The proportion of total cases involving military personnel varied widely from 20 to 85%. Investigation consistently showed that failure to apply elementary protective measures against sandfly bites was the most determinant factor in this proportion. Strict compliance with these measures appears to reduce the risk of infection considerably.

MOMP, a divergent porin from Campylobacter: cloning and primary structural characterization

We report a structural analysis at the molecular level of MOMP from Campylobacter, a gram-negative bacteria responsible for diarrhea. The corresponding gene was cloned and sequenced. Sequence comparison of seven MOMP sequences (three extracted from protein databases and four determined in this study) from distinct strains indicated alternation of preserved and divergent regions. No other significant sequence similarities could be detected. Comparison of MOMP with the crystal structures of other porins strongly suggested that it might adopt a similar fold and revealed the conservation of the monomer-monomer interface. The conservation clustered in the regions comprising or interacting with the loop L2. On the contrary, strands not involved in the interface are more divergent. Proteolysis assays and biochemical treatment supported the proposed model. Our study suggested that MOMP belong to the maltoporin super-family sharing common structural motifs. In view of this model we discuss its specificity and its global stability.

Molecular identification of a Nocardiopsis dassonvillei blood isolate

Nocardiopsis dassonvillei is an environmental aerobic actinomycete seldom isolated in cutaneous and pulmonary infections. We herein report the first N. dassonvillei blood isolate in a patient hospitalized for cholangitis. Although morphological characteristics and biochemical tests allowed a presumptive identification of this isolate, cell wall fatty acid chromatographic analysis confirmed identification at the genus level, and 16S rRNA gene sequencing achieved definite identification. This study illustrates the usefulness of 16S rRNA gene sequencing as a routine method for the identification of actinomycetes.

[Acute pericarditis of unusual etiology]

Extrapulmonary manifestations of Legionella pneumophilia infection are infrequent. Cardiac involvement can occur. We observed an unusual case which led to acute pericarditis and reviewed the literature on cardiac involvement, particularly pericarditis, in patients which legionellosis.