Insight into cross-talk between intra-amoebal pathogens.

Abstract: Background: Amoebae are phagocytic protists where genetic exchanges might take place between amoeba-resistant bacteria. These amoebal pathogens are able to escape the phagocytic behaviour of their host. They belong to different bacterial phyla and often show a larger genome size than human-infecting pathogens. This characteristic is proposed to be the result of frequent gene exchanges with other bacteria that share a sympatric lifestyle and contrasts with the genome reduction observed among strict human pathogens.Results: We sequenced the genome of a new amoebal pathogen, Legionella drancourtii, and compared its gene content to that of a Chlamydia-related bacterium, Parachlamydia acanthamoebae. Phylogenetic reconstructions identified seven potential horizontal gene transfers (HGTs) between the two amoeba-resistant bacteria, including a complete operon of four genes that encodes an ABC-type transporter. These comparisons pinpointed potential cases of gene exchange between P. acanthamoebae and Legionella pneumophila, as well as gene exchanges between other members of the Legionellales and Chlamydiales orders. Moreover, nine cases represent possible HGTs between representatives from the Legionellales or Chlamydiales and members of the Rickettsiales order.Conclusions: This study identifies numerous gene exchanges between intracellular Legionellales and Chlamydiales bacteria, which could preferentially occur within common inclusions in their amoebal hosts. Therefore it contributes to improve our knowledge on the intra-amoebal gene properties associated to their specific lifestyle.

Intra-articular osteoid osteoma of the knee: clinical and therapeutical particularities

The intra-articular osteoid osteoma (10-13% of the cases) is often difficult to identify. They present frequent atypical clinical signs and radiological images that eventually lead to inadequate treatment. For example, it has been observed that this pathology leads to inappropriate arthroscopies (up to 40%). Meniscal tear and then osteochondritis were initially suspected on a patient with an intra-articular osteoid osteoma at the tibia level. For the treatment, any damage of the cartilage has to be avoided. Thermoablation with radiofrequency is the treatment of choice

Hypertension and intra-operative incidents: a multicentre study of 125,000 surgical procedures in Swiss hospitals.

It is debated whether chronic hypertension increases the risk of cardiovascular incidents during anaesthesia. We studied all elective surgical operations performed in adults under general or regional anaesthesia between 2000 and 2004, in 24 hospitals collecting computerised clinical data on all anaesthetics since 1996. The focus was on cardiovascular incidents, though other anaesthesia-related incidents were also evaluated. Among 124,939 interventions, 27,881 (22%) were performed in hypertensive patients. At least one cardiovascular incident occurred in 7549 interventions (6% (95% CI 5.9-6.2%)). The average adjusted odds ratio of cardiovascular risk for chronic hypertension was 1.38 (95% CI 1.27-1.49). However, across hospitals, adjusted odd ratios varied from 0.41 up to 2.25. Hypertension did not increase the risk of other incidents. Hypertensive patients are still at risk of intra-operative cardiovascular incidents, while risk heterogeneity across hospitals, despite taking account of casemix and hospital characteristics, suggests variations in anaesthetic practices.

Variability of gait patterns during unconstrained walking assessed by satellite positioning (GPS).

It is established that the ratio between step length (SL) and step frequency (SF) is constant over a large range of walking speed. However, few data are available about the spontaneous variability of this ratio during unconstrained outdoor walking, in particular over a sufficient number of steps. The purpose of the present study was to assess the inter- and intra-subject variability of spatio-temporal gait characteristics [SL, SF and walk ratio (WR=SL/SF)] while walking at different freely selected speeds. Twelve healthy subjects walked three times along a 100-m athletic track at: (1). a slower than preferred speed, (2). preferred speed and (3). a faster than preferred speed. Two professional GPS receivers providing 3D positions assessed the walking speed and SF with high precision (less than 0.5% error). Intra-subject variability was calculated as the variation among eight consecutive 5-s samples. WR was found to be constant at preferred and fast speeds [0.41 (0.04) m.s and 0.41 (0.05) m.s respectively] but was higher at slow speeds [0.44 (0.05) m.s]. In other words, between slow and preferred speed, the speed increase was mediated more by a change in SF than SL. The intra-subject variability of WR was low under preferred [CV, coefficient of variation = 1.9 (0.6)%] and fast [CV=1.8 (0.5)%] speed conditions, but higher under low speed condition [CV=4.1 (1.5)%]. On the other hand, the inter-subject variability of WR was 11%, 10% and 12% at slow, preferred and fast walking speeds respectively. It is concluded that the GPS method is able to capture basic gait parameters over a short period of time (5 s). A specific gait pattern for slow walking was observed. Furthermore, it seems that the walking patterns in free-living conditions exhibit low intra-individual variability, but that there is substantial variability between subjects.

Continuous monitoring of liver oxygenation with near infrared spectroscopy during naso-gastric tube feeding in neonates.

Near infrared spectroscopy (NIRS) is a non-invasive method of estimating the haemoglobin concentration changes in certain tissues. It is frequently used to monitor oxygenation of the brain in neonates. At present it is not clear whether near infrared spectroscopy of other organs (e.g. the liver as a corresponding site in the splanchnic region, which reacts very sensitively to haemodynamic instability) provides reliable values on their tissue oxygenation. The aim of the study was to test near infrared spectroscopy by measuring known physiologic changes in tissue oxygenation of the liver in newborn infants during and after feeding via a naso-gastric tube. The test-retest variability of such measurements was also determined. On 28 occasions in 25 infants we measured the tissue oxygenation index (TOI) of the liver and the brain continuously before, during and 30 minutes after feeding via a gastric tube. Simultaneously we measured arterial oxygen saturation (SaO2), heart rate (HR) and mean arterial blood pressure (MAP). In 10 other newborn infants we performed a test-retest analysis of the liver tissue oxygenation index to estimate the variability in repeated intra-individual measurements. The tissue oxygenation index of the liver increased significantly from 56.7 +/- 7.5% before to 60.3 +/- 5.6% after feeding (p < 0.005), and remained unchanged for the next 30 minutes. The tissue oxygenation index of the brain (62.1 +/- 9.7%), SaO2 (94.4 +/- 7.1%), heart rate (145 +/- 17.3 min-1) and mean arterial blood pressure (52.8 +/- 10.2 mm Hg) did not change significantly. The test-retest variability for intra-individual measurements was 2.7 +/- 2.1%. After bolus feeding the tissue oxygenation index of the liver increased as expected. This indicates that near infrared spectroscopy is suitable for monitoring changes in tissue oxygenation of the liver in newborn infants.

Morphometric Vertebral Assessments via the Use of Dual X-ray Absorptiometry for the Evaluation of Radiographic Damage in Ankylosing Spondylitis: A Pilot Study.

We performed a pilot study to compare vertebral fracture assessments (VFA) and lateral X-rays in terms of inter- and intraobserver reliability and degree of correlation for the detection of syndesmophytes in ankylosing spondylitis (AS). We recruited 19 patients with AS and recent lumbar or cervical lateral X-rays with at least one syndesmophyte. Each patient underwent dual-energy X-ray absorptiometry with measurement of bone mineral density and dorso-lumbar VFA. Intra- and interreader reliability for VFA and X-rays were measured using 2 independent, blinded observers and Cohen's kappa values. An adapted modified Stoke Ankylosing Spondylitis Spinal Score (amSASSS) was generated with each method, and these 2 values correlated. For X-rays, intraobserver and interobserver agreement were 94.3% (κ = 0.83) and 98.6% (κ = 0.96), respectively; for VFA, corresponding values were 92.8% (κ = 0.79) and 93.8% (κ = 0.82). Overall agreement between the 2 techniques was 88.6% (κ = 0.72). The Pearson correlation coefficient for the 2 methods was 0.95 for the modified Stoke Ankylosing Spondylitis Spinal Score . Per dual-energy X-ray absorptiometry-generated bone mineral density, >50% of patients were osteopenic and 10% osteoporotic. In terms of reproducibility and correlation with X-rays, performing a VFA appears to be a candidate for assessing radiographic damage in AS, thought further research is necessary to justify this indication.

The inter-rater reliability of the Pulmonary Embolism Severity Index.

The Pulmonary Embolism Severity Index (PESI) is a validated clinical prognostic model for patients with acute pulmonary embolism (PE). Our goal was to assess the PESI's inter-rater reliability in patients diagnosed with PE. We prospectively identified consecutive patients diagnosed with PE in the emergency department of a Swiss teaching hospital. For all patients, resident and attending physician raters independently collected the 11 PESI variables. The raters then calculated the PESI total point score and classified patients into one of five PESI risk classes (I-V) and as low (risk classes I/II) versus higher-risk (risk classes III-V). We examined the inter-rater reliability for each of the 11 PESI variables, the PESI total point score, assignment to each of the five PESI risk classes, and classification of patients as low versus higher-risk using kappa (κ) and intra-class correlation coefficients (ICC). Among 48 consecutive patients with an objective diagnosis of PE, reliability coefficients between resident and attending physician raters were > 0.60 for 10 of the 11 variables comprising the PESI. The inter-rater reliability for the PESI total point score (ICC: 0.89, 95% CI: 0.81-0.94), PESI risk class assignment (κ: 0.81, 95% CI: 0.66-0.94), and the classification of patients as low versus higher-risk (κ: 0.92, 95% CI: 0.72-0.98) was near perfect. Our results demonstrate the high reproducibility of the PESI, supporting the use of the PESI for risk stratification of patients with PE.

Hepatic intra-arterial versus intravenous fotemustine in patients with liver metastases from uveal melanoma (EORTC 18021): a multicentric randomized trial.

BACKGROUND: In uveal melanoma (UM) with metastatic disease limited to the liver, the effect of an intrahepatic treatment on survival is unknown. We investigated prospectively the efficacy and toxicity of hepatic intra-arterial (HIA) versus systemic (IV) fotemustine in patients with liver metastases from UM. PATIENTS AND METHODS: Patients were randomly assigned to receive either IV or HIA fotemustine at 100 mg/m(2) on days 1, 8, 15 (and 22 in HIA arm only) as induction, and after a 5-week rest period every 3 weeks as maintenance. Primary end point was overall survival (OS). Response rate (RR), progression-free survival (PFS) and safety were secondary end points. RESULTS: Accrual was stopped after randomization of 171 patients based on the results of a futility OS analysis. A total of 155 patients died and 16 were still alive [median follow-up 1.6 years (range 0.25-6 years)]. HIA did not improve OS (median 14.6 months) when compared with the IV arm (median 13.8 months), hazard ratio (HR) 1.09; 95% confidence interval (CI) 0.79-1.50, log-rank P = 0.59. However, there was a significant benefit on PFS for HIA compared with IV with a median of 4.5 versus 3.5 months, respectively (HR 0.62; 95% CI 0.45-0.84, log-rank P = 0.002). The 1-year PFS rate was 24% in the HIA arm versus 8% in the IV arm. An improved RR was seen in the HIA (10.5%) compared with IV treatment (2.4%). In the IV arm, the most frequent grade ≥3 toxicity was thrombocytopenia (42.1%) and neutropenia (62.6%), compared with 21.2% and 28.7% in the HIA arm. The main grade ≥3 toxicity related to HIA was catheter complications (12%) and liver toxicity (4.5%) apart from two toxic deaths. CONCLUSION: HIA treatment with fotemustine did not translate into an improved OS compared with IV treatment, despite better RR and PFS. Intrahepatic treatment should still be considered as experimental. EUDRACT NUMBER AND CLINICALTRIALSGOV IDENTIFIER: 2004-002245-12 and NCT00110123.

Reproducibility and within-day variability of body fat measurements using segmental bipolar bioelectrical impedance in women

BACKGROUND AND AIMS: little is known regarding the reproducibility of body fat measuring devices; hence, we assessed the between and within-device reproducibility, and the within-day variability of body fat measurements. METHODS: body fat percentage was measured twice on seventeen female students aged between 18 and 20 with a body mass index of 21.9 ± 2.5 kg/m2 (mean ± SD) using seven bipolar bioelectrical impedance devices. Each participant was also measured each hour between 7:00 and 22:00. RESULTS: the correlation between first and second measurements was very high (Spearman r between 0.985 and 1.000, p<0.001), as well as between devices (Spearman r between 0.916 and 0.991, p<0.001). Repeated measurements analysis showed no differences were between devices (p=0.59) or readings (first vs. second: p=0.74). Conversely, significant differences were found between assessment periods throughout the day, measurements made in the morning being lower than those made in the afternoon (F test for repeated values= 6.58, p<0.001). CONCLUSIONS: the between and within-device reproducibility for measuring body fat is high, enabling the use of multiple devices in a single study. Conversely, small but significant changes in body fat measurements occur during the day, urging body fat measurements to be performed at fixed times.

The occurrence of intra-operative hypotension varies between hospitals: observational analysis of over 147000 anaesthesia

Background: Hypotension, a common intra-operative incident, bears an important potential for morbidity. It is most often manageable and sometimes preventable, which renders its study important. Therefore, we aimed at examining hospital variations in the occurrence of intraoperative hypotension and its predictors. As secondary endpoints, we determined to what extent hypotension relates to the risk of postoperative incidents and death. Methods: We used the Anaesthesia Databank Switzerland, built on routinely and prospectively collected data on all anaesthesias in 21 hospitals. The three outcomes were assessed using multi-level logistic regression models. Results: Among 147573 anaesthesia, hypotension ranged from 0.6 to 5.2% in participating hospitals, and from 0.3 up to 12% in different surgical specialties. Most (73.4%) were minor single events. Age, ASA status, combined general and regional anaesthesia techniques, duration of surgery, and hospitalization were significantly associated to hypotension. Although significantly associated, the emergency status of the surgery had a weaker effect. Hospitals' Odds Ratios for hypotension varied between 0.12 to 2.50 (p ≤0.001) with respect to the mean prevalence of 3.1%, even after adjusting for patient and anaesthesia factors, and for type of surgery. At least one postoperative incident occurred in 9.7% of the interventions, including 0.03% deaths. Intra-operative hypotension was associated with higher risk of post-operative incidents and death. Conclusions: Wide variations in the occurrence of hypotension amongst hospitals remain after adjustment for risk factors. Although differential reporting from hospitals may exist, variations in anesthesia techniques and blood pressure maintenance could have also contributed. Intra-operative hypotension is associated with morbidities and sometimes death, and constant vigilance must thus be advocated.