Peptidyl-Prolyl-cis/trans-Isomerases Mip and PpiB of Legionella pneumophila Contribute to Surface Translocation, Growth at Suboptimal Temperature, and Infection.

The gammaproteobacterium Legionella pneumophila is the causative agent of Legionnaires' disease, an atypical pneumonia that manifests itself with severe lung damage. L. pneumophila, a common inhabitant of freshwater environments, replicates in free-living amoebae and persists in biofilms in natural and man-made water systems. Its environmental versatility is reflected in its ability to survive and grow within a broad temperature range as well as its capability to colonize and infect a wide range of hosts, including protozoa and humans. Peptidyl-prolyl-cis/trans-isomerases (PPIases) are multifunctional proteins that are mainly involved in protein folding and secretion in bacteria. In L. pneumophila the surface-associated PPIase Mip was shown to facilitate the establishment of the intracellular infection cycle in its early stages. The cytoplasmic PpiB was shown to promote cold tolerance. Here, we set out to analyze the interrelationship of these two relevant PPIases in the context of environmental fitness and infection. We demonstrate that the PPIases Mip and PpiB are important for surfactant-dependent sliding motility and adaptation to suboptimal temperatures, features that contribute to the environmental fitness of L. pneumophila Furthermore, they contribute to infection of the natural host Acanthamoeba castellanii as well as human macrophages and human explanted lung tissue. These effects were additive in the case of sliding motility or synergistic in the case of temperature tolerance and infection, as assessed by the behavior of the double mutant. Accordingly, we propose that Mip and PpiB are virulence modulators of L. pneumophila with compensatory action and pleiotropic effects.

The EuroSCORE as predictor for prolonged hospital and intensive care stay after cardiac surgery?

OBJECTIVE: Validation of the EuroSCORE as predictor for a prolonged hospital and intensive care stay after CABG vs. institution-specific scoring systems. METHODS: For the evaluation of a prolonged hospital stay, 3359 patients were included in the analysis of EuroSCORE vs. the CORRAD morbidity score. For a prolonged intensive care stay, 1638 patients were included in the analysis of the EuroSCORE vs. the PICUS score. RESULTS: There was no significant difference in hospital stay between the three different EuroSCORE risk groups. The difference in hospital stay between the high-risk and low-risk groups, identified by the CORRAD morbidity score, was significant (6.9 vs.11.2 days). For a prolonged intensive care stay, the patients identified as high risk by the EuroSCORE and by the PICUS score also had a significantly longer intensive care stay; however, the discriminatory power was low. CONCLUSION: The EuroSCORE is not of value as a predictive system for a prolonged hospital stay. There is a relation between the high-risk patients identified by the EuroSCORE and a prolonged intensive care stay.

Identification of patients at risk for early out-of-hospital mortality after redocoronary artery surgery.

OBJECTIVE: Analyse risk factors and construct a predictive model for identification of patients at risk of early out-of-hospital mortality after coronary reoperations (RECABG). METHODS: 505 patients, discharged from hospital after a RECABG (1987-1998), were studied by univariate and multivariate analysis. A stepwise selective procedure (p<0.05) was used to identify a subset of variables with prognostic value for early out-of-hospital mortality. This subset was used to calculate a prognostic score 'S' and a predicted probability 'p' for early out-of-hospital mortality, p=1/1+ e-s. Sensitivity analysis was used for evaluation. RESULTS: The best predictive variables for early out-of-hospital mortality were diabetes (p=0.002), lung disease (p=0.05), emergency operation (p=0.0001) and a perioperative myocardial infarction (p=0.0001). Emergency operation (p=0.001) and antegrade/retrograde cardioplegia (p<0.0000) were independent predictors of a perioperative myocardial infarction. The prognostic accuracy (ROC area) was 86%. Patients were classified into low risk (5%), intermediate risk (15%), high risk (30%) and very high risk (≥40%). A predicted probability of ≥0.40 was used as cut-off point. The specificity of this test was 99%, sensitivity 33%, predictive value of a positive test 79%, and 95% for a negative test. CONCLUSION: The results show that patients discharged from hospital after RECABG can be stratified according to their early out-of-hospital risk. A perioperative myocardial infarction is the major independent risk factor and can be affected by use of retrograde cardioplegia.

Evaluation of long-term quality of life after reoperative coronary artery surgery: preliminary results.

OBJECTIVE: The risks of reoperative coronary artery bypass surgery (RECABG) still exceed those of a primary revascularisation and late results are not very favourable either. The subject of the present study is an evaluation of the long-term quality of life after RECABG. METHODS: We studied the outcome of 541 patients who underwent a RECABG from January 1987 to December 1998. The endpoint of the study was December 2002, or the patient's death. Quality of life, using the EuroQol registration, was evaluated. RESULTS: Hospital mortality was 6.7%. Follow-up was 95.6% complete, mean 7.7 years. There were 177 late deaths. The cumulative survival rates were 83.8, 76.9, and 60.6%, and cardiac survival rates were 84.8, 78.5, and 66.5%, at the one-year, five-year and ten-year follow-up, respectively. For 255 patients (89%), NYHA and EuroQol information was complete. In total 23% of the patients were in NYHA class I, 51% in class II, 21% in class III and 5% were in class IV. In the EuroQol registration, 54% of the patients declared they had no mobility problems, 85% no problems with self-care, and 65% no problems with usual activities. However, 60% suffered from moderate pain or discomfort, and 33% from anxiety or depression. On the visual analogue scale (mean 63.5), 13% of the patients scored >90, 68% between 50 and 90, and 19% of the patients <50. CONCLUSION: The long-term results of cumulative survival and cardiac survival, and NYHA class in our patient population who underwent RECABG are comparable with other studies. Quality of life is acceptable regarding the high risk of a RECABG.

Papillary fibroelastoma of the mitral valve.

We present a case of a 69-year-old woman with a history of stroke five years previously and an abnormal ECG prior to eye surgery. There were no signs of cardiac disease. Echocardiography disclosed a tumour of the papillary muscle. Surgical excision was performed and histological examination confirmed the diagnosis of a papillary fibroelastoma.

Smoking behaviour of patients undergoing cardiac surgery.

OBJECTIVES: Investigate smoking behaviour and opinions on tobacco use in patients undergoing cardiac surgery. METHODS: In this descriptive study, 200 patients were preoperatively asked to complete a questionnaire on their 'smoking habits'. Smoking behaviour, smoking cessation, tobacco and health, smoking in hospital and smoking after the operation were the main subjects. Eighty percent of the questionnaires (161 patients) could be used in the study. The total group was divided into three groups: group A: patients smoking at the moment of hospitalisation, group B: patients who had stopped smoking and group C: patients who had never smoked. RESULTS: There is a difference in the answers between the three groups. For most patients the relation between tobacco use and cardiovascular disease is not clear; there is obviously an information gap. More than 50% of the patients do not agree with smoking in hospital, not even in 'smokers rooms'. Most patients have the intention of stopping smoking after their heart operation. This is an individual decision and support seems minimal. CONCLUSION: This study confirms that the relation between smoking and cardiovascular diseases is not clear for many cardiac patients. Hospitalisation can be a good moment for smoking cessation, but support is necessary.

A nineteen-millimetre aortic valve prosthesis: is this really a risk?

BACKGROUND: Aortic valve replacement in patients with a small aortic root is a subject of ongoing controversy. We summarised our clinical experience with aortic valve replacement with 19 mm valves and combined this with a review of literature. METHODS: Between January 1994 and December 1999, 603 patients underwent aortic valve replacement; 51 of these patients (8.3%) received a 19 mm heart valve prosthesis. The mean age was 72±9.7 years. Twenty-eight patients had concomitant coronary artery disease, six patients a combined mitral or tricupid valve disease. In four patients, the intervention was a reoperation. The mean EuroSCORE of the total group was 6.4±2.8, and 34 patients had a high operative risk. RESULTS: Hospital mortality was 7.8% (4/51 patients). Follow-up of 47 hospital survivors was complete. At 12 months the survival was 90%, at 24 months 85% and at 48 months 60%. NYHA class improved at least one class in 35 patients (85%), and 34 patients declared that their quality of life had improved since the operation. CONCLUSION: Aortic valve replacement with a small (19 mm) prosthesis can be performed with an acceptable operative mortality and results in excellent symptomatic improvement and quality of life.