Availability of global health opportunities in North American Paediatric Orthopaedic Fellowship Programmes.

PURPOSE: Orthopaedic residents are increasingly seeking international health electives (IHEs) during training, many of which involve providing paediatric orthopaedic care. However, little is known about the availability of IHEs during orthopaedic fellowship training. Our study sought to assess the global health opportunities available to North American paediatric orthopaedic fellows. METHODS: We conducted an online, REDCap-based survey of paediatric orthopaedic fellowship programme directors (PDs) in the United States and Canada. The survey link was sent by the Pediatric Orthopaedic Society of North America (POSNA) Evidence-Based Medicine Committee to all POSNA-approved paediatric orthopaedic fellowship PDs. Follow-up reminder emails were delivered at set time intervals. RESULTS: The overall response rate was 55% (26/47). Only three of 26 responding programmes (11.5%) offered a structured global health programme but 42.3% of programmes (11/26) reported fellow IHE participation within the last ten years. In all, 91% of PDs reported that fellows were extremely satisfied with their IHE, and 91% agreed that IHEs are valuable for trainees. Perceived barriers to fellow participation in IHEs included lack of funding, lack of established partner sites, lack of interest among fellows and concerns related to time away compromising clinical/call coverage. In all, 65.4% of PDs agree that IHE participation during training plays a major role in shaping fellows' future volunteer activities. CONCLUSION: There are limited global health opportunities among North American paediatric orthopaedic fellowship programmes, with only 11.5% offering a structured global health programme. Greater efforts to establish sustainable funding and international partnerships may increase opportunities for IHEs during paediatric orthopaedic fellowship training. LEVEL OF EVIDENCE: Level II.

Shrinking a large dataset to identify variables associated with increased risk of Plasmodium falciparum infection in Western Kenya.

Large datasets are often not amenable to analysis using traditional single-step approaches. Here, our general objective was to apply imputation techniques, principal component analysis (PCA), elastic net and generalized linear models to a large dataset in a systematic approach to extract the most meaningful predictors for a health outcome. We extracted predictors for Plasmodium falciparum infection, from a large covariate dataset while facing limited numbers of observations, using data from the People, Animals, and their Zoonoses (PAZ) project to demonstrate these techniques: data collected from 415 homesteads in western Kenya, contained over 1500 variables that describe the health, environment, and social factors of the humans, livestock, and the homesteads in which they reside. The wide, sparse dataset was simplified to 42 predictors of P. falciparum malaria infection and wealth rankings were produced for all homesteads. The 42 predictors make biological sense and are supported by previous studies. This systematic data-mining approach we used would make many large datasets more manageable and informative for decision-making processes and health policy prioritization.

Tonsillotomy: facts and fiction.

In contrast to total or extracapsular tonsillectomy (TE), subtotal/intracapsular/partial tonsillectomy (SIPT) or tonsillotomy (TT) is associated with significant less postoperative morbidity. It has been stated that patients older than 8 years of age or with a history of tonsillitis should be excluded from SIPT/TT. Some health insurance companies mandate utilization of particular surgical instruments. Finally, it has been stated that the remaining tonsillar tissue may become a subject of recurrent tonsillitis or tonsillar regrowth, in both cases requiring revision surgery in terms of TE. This literature review was undertaken to clarify what has been validated in the literature concerning indications, surgical techniques, complications and outcome of SIPT/TT as reported since 1960. A Medline review was undertaken and all papers included that were published in English or German language until September 30, 2013. Exclusion criteria were: publication date 1960 and earlier, other languages, no relation to tonsil surgery, papers not available to the authors, uncommon surgical techniques, national surveys or studies without patients. The quality of the papers was classified according to "The Oxford 2011 Levels of Evidence". The surgical techniques were classified according to Windfuhr and Werner and extended to interstitial tonsil therapy. Other issues were: study period, hemorrhage, dehydration, intake of analgesics, return to normal diet, surgical instruments, operation time, number of surgeons involved, number of patients, age, indications, follow-up, rate of tonsillar regrowth, tonsillitis and secondary TE. A total of 379 different publications were retrieved, but only 86 studies found eligible for further analysis. There were 10,499 patients in the study groups and 10,448 patients in the control groups. Utilization of the microdebrider largely prevailed, followed by Coblation, CO2-LASER, surgical scissor, Radiofrequency, Interstitial ThermoTherapy with various instruments, Diode-LASER, and other instruments. Instruments were not specified for 1,815 patients. Data for operation time, intraoperative bleeding, return to normal diet, analgesic intake were in favor for SIPT/TT and ablation procedures. Regrowth and tonsillitis occurred in rates of <6 % on average. Secondary surgery became necessary in only every third patient of this subgroup. Studies of variable quality impede comparison of all aspects in the papers. At least every second study did not address issues like operation time, intraoperative bleeding, return to normal diet, analgesic intake, rates of tonsillar regrowth, postsurgical tonsillitis and secondary TE. There are insufficient data to show that a single surgical instrument is superior. A history of tonsillitis and an age >8 years are definitely not commonly accepted as contraindication for SIPT, TT or ablation procedures. There is a strong evidence that pain is less after SIPT, TT and tonsil ablation resulting in an earlier return to normal diet and activity. Large, well-designed randomized controlled trials with an adequate follow-up are necessary to determine whether the procedure is capable to replace TE to resolve upper airway obstruction resulting from tonsillar hypertrophy as well as recurrent episodes of tonsillitis in children and adults.

Transmission of Escherichia coli O157:H7 in cattle is influenced by the level of environmental contamination.

A pen infection-transmission experiment was conducted to elucidate the role of pathogen strain and environmental contamination in transmission of Escherichia coli O157:H7 (ECO157) in cattle. Five steers were inoculated with a three-strain mixture of ECO157 and joined with five susceptible steers in each of two experimental replicates. Faecal and environmental samples were monitored for ECO157 presence over 30 days. One ECO157 strain did not spread. Transmission rates for the other two strains were estimated using a generalized linear model developed based on a modified 'Susceptible-Infectious-Susceptible' mathematical model. Transmission rates estimated for the two strains (0·11 and 0·14) were similar. However, the rates significantly (P = 0·0006) increased 1·5 times for every 1-unit increase in the level of environmental contamination measured as log10 c.f.u. Depending on the level of environmental contamination, the estimated basic reproduction numbers varied from <1 to 8. The findings indicate the importance of on-farm measures to reduce environmental contamination for ECO157 control in cattle that should be validated under field conditions.

[Electrical myostimulation: improvement of quality of life, oxygen uptake and left ventricular function in chronic heart failure]. / Elektromyostimulation: Verbesserung von Lebensqualität, Sauerstoffaufnahme und linksventrikulärer Funktion bei chronischer Herzinsuffizienz.

AIM OF THE STUDY: Regular physical activity has found to be a strategy to increase exercise capacity in patients with chronic heart failure (CHF). Next to endurance training also electromyostimulation (EMS) of thigh and gluteal muscles results in an increased capacity in CHF patients. EMS therapy was either done by stimulating 8 major muscle groups involving also trunk and arm muscles (extended electromyostimulation (exEMS)) in comparison to EMS therapy limited to gluteal and leg muscles (limEMS). METHODS: 31 individuals completed the EMS training program. Stable CHF patients (NYHA class II-III) received either exEMS (18 patients, 11 males, mean age 59.8±13.8 years) or limEMS (13 patients, 10 males, 63.6±9.4 years). Training was performed for 10 weeks twice weekly for 20 min, the level of daily activity remained unchanged. Effects on exercise capacity, left ventricular function (EF - ejection fraction) and QoL (quality of life) were evaluated. RESULTS: QoL was found to be improved in all domains of the SF-36 questionnaire. In the exEMS group there was a significant improvement in the domain physical functioning (54.09±29.9 to 75.45±15.6, p=0.48) and emotional role (63.63±45.8 to 93.93±20.1 p=0.048). LimEMS group showed significant improvement in the domain vitality (37.5±6.9 to 52.8±12.5, p=0.02).There was a significant increase of oxygen uptake at aerobic threshold in all groups (exEMS: +29.6%, p<0.001; limEMS +17.5%, p<0.001). EF -increased from 36.94±8.6 to 42.36±9.1% (+14.7%, p=0.003) in the exEMS group (limEMS 37.7±3.6 to 40.3±5.9% [+6.9%, p=0.18]). CONCLUSION: EMS contributes to an improved quality of life and can improve oxygen uptake and EF in CHF. It may be an alternative therapy in CHF patients who are otherwise unable to undertake conventional forms of exercise training.

Left ventricular mass and oxygen uptake in top handball athletes.

The key challenge in athlete's screening is the distinction between abnormal and normal which is hindered by the fact that the adaptation to sports activity in endurance athletes is different to that in power athletes. Especially cardiomyopathies provoke changes in ECG and echocardiography (echo) at an early stage when clinical symptoms are absent. ECG and echo data and their relationship to fitness peculiar to top handball players have never been described. We studied 291 male first league handball players (32 Olympians/47 national players) (25.3±4.4 years). Check up consisted of ECG, spiroergometry and echocardiography. None had T-wave inversions, 3.1% showed early repolarisation abnormalities in the precordial leads. Sokolow-Lyon voltage criterion for left ventricular hypertrophy was positive in 19.3%. Spiroergometry showed a maximum oxygen uptake (peakVO2) of 50.3±7.7 ml/min/kg body weight. LVmass was increased in comparison to normal values. There was a correlation between peakVO2 and LVindex (p<0.001, r=0.341), (LVmass/peak VO2 p=0.053, r=0.125). A relationship between cardiac dimensions and peakVO2 could not be confirmed. In professional handball players early repolarisation abnormalities were less frequent and LVmass was increased when compared with soccer players. The need for normal values for different types of sports is crucial to guarantee a proper evaluation of athletes.

Stent restenosis and thrombosis: etiology, treatment, and outcomes.

The implementation of bare metal stents and later drug eluting stents (DES) proved to be an important step forward in reducing rates of restenosis after percutaneous coronary intervention. Despite all the benefits of DES, concerns have been raised over their long term safety as especially stent thrombosis sets patients at risk. In view of the overall low frequency of stent thrombosis, large sample sizes are needed to evaluate accurately treatment differences between stents. However, a consistent finding from randomized, controlled trials of DES versus bare metal stents is the significantly reduced reintervention rate associated with DES use. The clinical presentation of restenosis is recurrent angina or acute coronary syndrome. Optimal implantation of the stent in the vessel and adequate antiplatelet therapy are of utmost significance to provide best results. Intravascular imaging often helps to provide optimal delivery of the stent. Newer stents have now been developed. Especially DES with biogradable polymers, novel coatings of the stent, and polymer free DES have to be mentioned and early results seem to be promising. The perspective of bioresorbable DES platforms includes the additional benefits of improved recovery in vessel function and the potential for reducing the requirement for prolonged dual antiplatelet therapy. This article reviews the etiology, treatment options and outcome of in stent restenosis and gives an overview about the new developments in the field of stent technology.

[Renal sympathetic denervation--physical-antomical basics, procedure, and analysis of clinical and technical parameters on procedure success and efficacy]. / Renale sympathische Denervierung: physikalisch-anatomische Grundlagen, technisches Vorgehen und Analyse klinischer und technischer Einflussgrößen auf die Effizienz der Hochfrequenzablation.

BACKGROUND: Evidence from human and animal models indicate that excessive central sympathetic nerve activity (SNA) plays a pathogenic role in triggering and sustaining hypertension. Thus, treatments targeting this neurogenic (sympathetic) triggered hypertension were evaluated and renal sympathetic denervation (RND) showed promising results. However, little is known about the parameters influencing efficacy of high frequency energy in the arterial model. PATIENTS AND METHODS: Data from all 40 consecutive patients suffering from therapy-resistant hypertension who underwent RND and completed a 1-year follow-up were retrospectively analyzed. We focussed on procedural success, complications and efficacy (office-blood pressure, 24-h-blood pressure) and its correlations to quantity of ablations and intima media thickness. RESULTS: In all patients (65.9 ± 11.6 years (range 42-83); 72.5% male) the procedure was successful. Ablations with arterial access from the upper extremity were technically unsuccessful. With the use of 13.6 ± 1.7 (10-17) ablations, office-blood pressure (1-year) could be reduced from 162/89 mmHg to 142/82 mmHg and 24-h-blood pressure from 149/83 mmHg to 139/79 mmHg, respectively, including a medium to strong correlation to quantity of ablations (r = 0.57, r = 0.63) while documenting only a weak correlation to IMT (r = -0.29, r = -0.25). CONCLUSION: In comparison to the Simplicity studies, the hypertension lowering effects were less profound but consistently present over time in the 24-h-blood pressure assessments. The positive correlation of the quantity of ablations we found seems to be plausible regarding the unpredictable allocations of the sympathetic nerves i.e. in profoundly kinking vessels in hypertensives. The physics of high-frequency energy application in the arterial model needs further research.

Investigation of quaternary ammonium silane-coated sand filter for the removal of bacteria and viruses from drinking water.

AIMS: To develop an anti-microbial filter media using an attached quaternary ammonium compound (QAC) and evaluate its performance under conditions relevant to household drinking water treatment in developing countries. METHODS AND RESULTS: Silica sand was coated with dimethyloctadecyl [3-(trimethoxysilyl) propyl] ammonium chloride via covalent silane chemistry. Filter columns packed with coated media were challenged with micro-organisms under different water quality conditions. The anti-bacterial properties were investigated by visualizing Escherichia coli (E. coli) attachment to coated media under fluorescence microscopy combined with a live/dead stain. A 9-cm columns with a filtration velocity of 18 m h(-1) achieved log(10) removals of 1·7 for E. coli, 1·8 for MS2 coliphage, 1·9 for Poliovirus type 3 and 0·36 for Adenovirus type 2, compared to 0·1-0·3 log(10) removals of E. coli and MS2 by uncoated sand. Removal scaled linearly with column length and decreased with increasing ionic strength, flow velocity, filtration time and humic acid presence. Escherichia coli attached to QAC-coated sand were observed to be membrane-permeable, providing evidence of inactivation. CONCLUSIONS: Filtration with QAC-coated sand provided higher removal of bacteria and viruses than filtration with uncoated sand. However, major limitations included rapid fouling by micro-organisms and natural organic matter and low removal of viruses PRD1 and Adenovirus 2. SIGNIFICANCE AND IMPACT OF THE STUDY: QAC-coated media may be promising for household water treatment. However, more research is needed on long-term performance, options to reduce fouling and inactivation mechanisms.

The concept of an anatomy related individual arterial access: lowering technical and clinical complications with transradial access in bovine- and type-III aortic arch carotid artery stenting.

BACKGROUND: Carotid artery stenting (CAS) from the femoral approach can be anatomically very difficult and the incidence of complications is higher in patients with anatomical variations of the aortic arch, difficulties related to peripheral vascular disease and/or with access site complications. Because the typical morphology in patients with a bovine- or type-III aortic arch applies for an arterial access from the right upper extremity (e.g. radial, brachial) we evaluated success rates and safety of the right transradial access in a prospective study. PATIENTS AND METHODS: Between June 2009 and October 2010, seventeen patients (mean age 74,4 ± 9 years, 10 male) with a bovine- (n = 4) or type-III aortic arch (n = 12) underwent CAS with a planned transradial- (n = 3) or after problematic transfemoral access (n = 14). In patients with a type-III aortic arch (n = 13), the right target common carotid artery (CCA) was cannulated from the right radial artery with a 5F IMA diagnostic catheter-, in patients with a bovine aortic arch (n = 4), the left CCA was accessed from the right radial artery with a 5F Amplatz- or Judkins left catheter. In all patients a 6F- (n = 14) or 5F- (n = 3) shuttle sheath was inserted via the diagnostic catheter and a 0.035” extra-stiff guidewire. All interventions were carried out with the use of a peripheral embolization protection device (EPD). Primary study endpoints were procedural success and major adverse cardiac and cerebrovascular events (MACCE), secondary endpoints were access site complications and the mean intervention time. RESULTS: Procedural success could be achieved in all patients (100 %), MACCE and access site complications did not occur in any patient. Mean interventional time was 48 ± 18 min. CONCLUSIONS: CAS using the right transradial approach for left CAS in bovine-type aortic arch or the right transradial approach in type-III aortic arch for right CAS appears to be safe and technically feasible.

Transradial access in percutaneous coronary interventions: technique and procedure.

After showing significantly lower complication rates in diagnostic coronary angiography, the radial artery access was successfully introduced as a useful vascular access site for transradial percutaneous coronary intervention in order to enhance patients' comfort and reduce hospital workload and costs. Moreover, due to the reduced need for antiplatelet therapy cessation as a result of lower bleeding complications, patients treated with transradial access showed a significantly better cardiac outcome in randomized interventional acute coronary syndrome studies.Procedural success and postprocedural radial arteritis or radial occlusions are closely related to anatomical circumstances (e.g., anomalous radial branching patterns, tortuosity, e.g., radial loops and small radial artery diameters), or risk factors for radial spasms (e.g. smoking, anxiety, vessel diameter, age, gender) which can effectively be reduced by the use of smaller catheters (4-5 Fr) and the administration of an adjuvant pharmacological therapy before (3000 U heparin, verapamil, nitroglycerine) and after (ibuprofen) the intervention.For successful radial sheath access and transradial catheterization, it is important to use dedicated radial access needles ≤ 21-gauge and steel wires ≤ 0.018 in. In order to pass the brachiocephalic trunk without difficulties or complications and access the ascending aorta, the use of inspiration maneuvers is of central importance.

Isoprenoid depletion by statins antagonizes cytokine-induced down-regulation of endothelial nitric oxide expression and increases NO synthase activity in human umbilical vein endothelial cells.

Endothelial dysfunction and atherosclerosis are associated with an inflammation-induced decrease in endothelial nitric oxide synthase (eNOS) expression. Based on the differences between hydrophobic and hydrophilic statins in their reduction of cardiac events, we analyzed the effects of rosuvastatin and cerivastatin on eNOS and inducible NO synthase (iNOS) expression and NOS activity in TNF-alpha-stimulated human umbilical vein endothelial cells (HUVEC). Both statins reversed down-regulation of eNOS mRNA and protein expression by inhibiting HMG-CoA reductase and isoprenoid synthesis. Cerivastatin tended to a more pronounced effect on eNOS expression compared to rosuvastatin. NOS activity - measured by conversion of [(3)H]-L-arginine to [(3)H]-L-citrulline - was enhanced under treatment with both drugs due to inhibition of HMG-CoA reductase. Statin-treatment reduced iNOS mRNA expression under normal conditions, but had no relevant effects on iNOS mRNA expression in cytokine-treated cells. Rosuvastatin and cerivastatin reverse the detrimental effects of TNF-alpha-induced down-regulation in eNOS protein expression and increase NO synthase activity by inhibiting HMG-CoA reductase and subsequent blocking of isoprenoid synthesis. These results provide evidence that statins have beneficial effects by increasing eNOS expression and activity during the atherosclerotic process.

Directional atherectomy facilitates the interventional procedure and leads to a low rate of recurrent stenosis in left anterior descending and left circumflex artery ostium stenoses: subgroup analysis of the FLEXI-CUT study.

OBJECTIVES: To examine by retrospective analysis of data from the FLEXI-CUT monocentre registry whether atherectomy can effectively simplify complex stent implantation in ostial bifurcation lesions by reducing the procedure to stenting of the left anterior descending (LAD) or left circumflex (LCX) artery ostium alone. PATIENTS AND METHODS: All patients who had been enrolled in the prospective FLEXI-CUT study (directional atherectomy with adjunctive balloon angioplasty) were retrospectively analysed on the basis of significant LAD or LCX ostial stenosis (>or= 70% stenosis) deriving from an undiseased left main stem. The primary combined end point was the rate of target lesion revascularisation (TLR) and binary restenosis; secondary end points were procedural success and major adverse cardiac events (MACE) at the six-month follow up. RESULTS: Of 30 patients enrolled with significant LAD or LCX ostium stenosis, 29 were effectively treated with directional atherectomy (96.7% procedural success). All patients underwent single-vessel stenting procedures of solely the LAD or LCX ostium. At follow up, binary stenosis was 25% (6 of 24), TLR (angiographic plus clinical) 10.3% (3 of 29) and total MACE 6.9% (2 of 29). CONCLUSIONS: Directional atherectomy with single-vessel stenting procedures facilitates the interventional treatment of LAD and LCX ostium stenosis, and leads to remarkably low TLR and binary stenosis at follow up.

Radiation-reducing planning of cardiac catheterisation.

Any radiation exposition for medical purposes should be kept as low as is reasonably achievable. Mean patient radiation exposure of diagnostic cardiac catheterisation is high (16-106 Gy x cm2) and for this reason the International Commission on Radiological Protection (ICRP) recommends credentialing radiation protection training programmes. Twenty cardiologists each documented various dose parameters of 10 cardiac catheterisations, before and after a 90-minute mini-course of the ELICIT study group ("Encourage to Less Irradiating Cardiologic Interventional Techniques"), and could achieve a reduction of the mean dose-area product by 15.9+/-9.0 Gy x cm2, equivalent to 47%. The presented radiation-reducing planning of invasive cardiac catheterisation for this reason is the first one validated in clinical routine and consists of 6 standard runs--one for the left ventricle, 3 and 2 for the left (LCA) and right coronary artery (RCA), respectively--depending on anatomy and findings supplemented by 1...4 special projections. The caudal posteroanterior (PA) view documents the left coronary main stem, proximal and distal left anterior descending artery (LAD), and proximal and mid circumflex segments. The cranial PA view however is suitable for the left coronary orifice, circumflex periphery, LAD, all diagonal bifurcations, and collateral pathways towards the RCA. LCA standard angiography is completed by lateral 90 degrees/0 degrees left anterior oblique (LAO) angulation. The 60 degrees/0 degrees LAO angulation visualises the right posterolateral artery (RPL) and the RCA to its bifurcation. The more proximal one finds the bifurcation, the more the second standard cranial PA view for RCA should vary towards the cranial right anterior oblique (RAO) and finally 30 degrees/0 degrees RAO view. The efficiency of these less-irradiating angulations are improved by radiation-reducing techniques as follows: restriction to essential radiographic frames and runs, consistent collimation to the region of interest--particularly during coronary intubation--, adequate instead of best possible image quality, short skin-to-image-intensifier distance, inspiration during radiography, preference for projections that rotate out the spine, optimisation of fluoroscopy time, well-experienced and well-rested interventionists.

[Fluoroscopy time -- an overestimated factor for patient radiation exposure in invasive cardiology]. / Durchleuchtungszeit -- Ein überschätzter Parameter der Patientendosis in der invasiven Kardiologie.

PURPOSE: To analyze the effects of an optimized fluoroscopy time on patient radiation exposure in the course of coronary angiography (CA) and percutaneous coronary interventions (PTCA), in comparison to those with consistent collimation to the region of interest (ROI). Furthermore, to analyze efforts concerning reduction of radiographic frames as well as concerning adequate instead of best possible image quality. MATERIAL AND METHODS: For 3,115 elective CAs and 1,713 PTCA performed by one interventionist since 1997, we documented the radiographic dose-area products (DAP (R)) and fluoroscopic dose-area products (DAP (F)), the number of radiographic frames and the fluoroscopy times during selected 2-month intervals. Under conditions of constant image intensifier entrance dose, levels of DAP (R)/frame and DAP (F)/s represent valid parameters for consistent collimation. RESULTS: In 1997, the mean baseline values of DAP for elective CA and PTCA amounted to 37.1 and 31.6 Gy x cm (2), respectively. A reduction of mean fluoroscopy times from 264 to 126 seconds for CA and from 630 to 449 seconds for PCI, both resulted in an overall DAP-reduction of merely 20 %. Optimization of mean radiographic frames from 543 to 98 for CA and from 245 to 142 for PTCA enabled reductions of 53 and 13 %, respectively. By restriction to adequate instead of best-possible image quality for coronary angiography in clinical routine, we achieved an optimized radiographic DAP/frame of 30.3 to 13.3 mGy x cm (2), which enabled a 45 % reduction of overall DAP. Most efficient however was a consistent collimation to the ROI, which resulted in a remarkable radiation reduction by 46 % for CA and by 65 % for PTCA. CONCLUSIONS: Radiation-reducing educational efforts in the clinical routine of invasive cardiology should -- against widely held opinion -- focus less exclusively toward a reduction of fluoroscopy time but more efficiently toward consistent collimation to the region of interest, reduction of radiographic frames and restriction to an adequate instead of best-possible image quality.