170 Social and Environmental Benefits of Virtual Fracture Clinics in Trauma and Orthopaedic Surgery: Reduced Patient Travel Time, Patient Cost and Air Pollutant Emissions

Aim

Several papers have analysed the clinical benefits and safety of Virtual Fracture Clinics (VFCs). A significant increase in the use of Trauma and Orthopaedic (T&O) VFCs was seen during the COVID-19 pandemic. This study aims to investigate the social impact of VFCs on the travel burden and travel costs of T&O patients, as well as the potential environmental benefits in relation to fuel consumption and travel-related pollutant emissions.

Method

All patients referred for T&O VFC review from March 2020 to June 2020 were retrospectively analysed. The travel burden and environmental impacts of hypothetical face-to-face consultations were compared with these VFC reviews. The primary outcomes measured were patient travel time saved, patient travel distance saved, patient cost savings and reduction in air-pollutant emissions.

Results

Over a four-month period, 1359 VFC consultations were conducted. The average travel distance saved by VFC review was 88.6 kilometres (range 3.3-615), with an average of 73 minutes (range 9-390) of travel-time saved. Patients consumed, on average, 8.2 litres (range 0.3-57.8) less fuel and saved an average of €11.02 (range 0.41-76.59). The average reduction in air-pollutant vehicle emissions, including carbon dioxide, carbon monoxide, nitric oxides and volatile organic compounds was 20.3 kilograms (range 0.8-140.8), 517.3 grams (g) (range 19.3-3592.3), 38.1g (range 1.4-264.8) and 56.9g (range 2.1-395.2), respectively.

Conclusions

VFCs reduce patient travel distance, travel time and travel costs. In addition, VFCs confer significant environmental benefits through reduced fuel consumption and reduction of harmful environmental emissions.

POS1190 EXPECTATIONS AND POTENTIAL CONCERNS OF PATIENTS WITH AUTOIMMUNE AND RHEUMATIC DISEASES REGARDING VACCINATION AGAINST SARS-CoV-2 (COVID-19): THE WORLDWIDE ONLINE VAXICOV STUDY

Background:

Vaccination is an important and effective tool to prevent infections in the general population as well as in patients with systemic autoimmune or inflammatory rheumatic diseases (AIIRDs) who may be at increased risk of serious infection. While the global race for vaccines against COVID-19 has already lead to first authorizations and vaccinations in some countries, multiple questions arise for access and provisions as well as for the acceptance of vaccine policies by immunocompromised patients.

Objectives:

We conducted an international survey about expectations and potential concerns regarding SARS-CoV-2 vaccine in patients with AIIRDs and healthcare professionals.

Methods:

The online study consisted of 57 questions which addressed determinants associated with SARS-2-CoV-2 vaccine willingness. Dissemination was ensured through social media and patient associations between December 12 and December 21, 2020.

Results:

The study included 1266 patients with AIIRDs and 265 healthcare professionals from 56 countries. SARS-CoV-2 vaccine willingness was reported by 54.2% of AIIRD patients (uncertainty in 32.2% and unwillingness in 13.6%) and 74.0% of healthcare professionals. In patients, the willingness to get vaccinated increased significantly with age (p<0.0001) and was strongly associated with the fear to be infected by SARS-CoV-2 (p<0.0001) or to develop severe COVID19 (p<0.0001) but not with presence of additional comorbidities (p=0.71) or immunocompromised status (p=0.94). The most trusted healthcare professional regarding the recommendation to get vaccinated against COVID-19 was their specialist (rheumatologist, internist, etc.) for 69.9%. Vaccine unwillingness was low (7.9%) among healthcare professionals and willingness was significantly increased in those who had been vaccinated against influenza in the last 3 years (p=0.01).

Subject groupsPatientsHealthcare professionalsN1266265Age (years), median [IQR25-75]50 [40-61]40 [32.5-53]Female, n (%)1141 (90.1%)150 (56.6%)Male, n (%)115 (9.9%)115 (43.4%)Country, n (%) France320 (25.3%)159 (60%) UK345(27.3%)4 (1.5%) Chile123 (9.7%)4 (1.5%) USA114 (9.0%)7 (2.6%) Venezuela43 (3.4%)26 (9.8%) Spain57 (4.5%)3 (1.1%) Mexico53 (4.2%)3 (1.1%) Argentina45 (3.6%)8 (3.0%) Other*166 (13.1%)51 (19.2%)Rheumatic diagnosis, n (%)1266- Systemic lupus erythematosus492 (38.9%)- Spondyloarthritis176 (13.9%)- Rheumatoid arthritis160 (12.6%)- Giant cell arteritis / Polymyalgia rheumatica144 (11.4%)- Primary anti-phospholipid syndrome64 (5.1%)- Inflammatory myositis62 (4.9%)- Relapsing polychondritis45 (3.6%)- Other**123 (9.7%)--Health professionals, n (%)-265 Doctor-203 (76.6%) Nurse (or equivalent)-23 (8.7%) Nursing assistant-11 (4.2%) Other***-28 (10.6%)Associated comorbidities, n (%) Diabetes69 (5.5%)6 (2.3%) Hypertension267 (21.1%)24 (9.1%) Myocardial infarction, stroke, transient stroke60 (4.7%)1 (0.4%) Respiratory disease (asthma, chronic bronchitis, emphysema, etc.)169 (13.3%)13 (4.9%)Renal failure47 (3.7%)1 (0.4%)Obesity (BMI > 30)228 (18.0%)18 (6.8%)At least one associated comorbidity, n (%)588 (46.4%)50 (18.9%)Smoker, n (%)128 (10.2%)22 (8.3%) Current411 (32.7%)51 (19.2%) Past719 (57.1%)192 (72.5%) NeverUse of oral glucocorticoids, n (%)551 (56.1%)3 (1.1%)Immunocompromised$, n (%)770 (60.8%)0On a 0 to 10 scale, median8 (6-10)5 (3-8)[IQR25-75]9 (7-10)5 (1-8)−Afraid to get infected by SARS-CoV-2−Afraid to get a severe COVID-19Willing to get vaccinated (Yes / uncertain / No), %54.2 / 32.2 / 13.674.0 / 18.1 / 7.9Vaccine hesitancy, n (%)357 (28.2%)59 (22.3%)

Conclusion:

Data from this study are crucial to understand the main expectations and concerns regarding SARS-CoV-2 vaccination in patients with AIIRDs and healthcare workers and allow the identification of valuable strategies to increase vaccine coverage in those populations.

Acknowledgements:

We wish to acknowledge the crucial role of the following patient associations: LupusEurope (tweeter: @LupusEurope), Agrupacion Lupus Chile (@Lupus_Chile), RarasNoInvisibles (@Noinvisibles), Lupus UK, Lupus France, SPONDYL’ASSO, Spondyl(O)action, AFL+, in the dissemination of the survey. We are indebted to Gonzalo Tobar Carrizo (@pinkycito) for the Spanish translation of the survey, all patients, families, and health professionals for their kind participation in our study. We wish to thank Ms. Sylvie Thuong for her invaluable assistance.

Disclosure of Interests:

Renaud FELTEN Speakers bureau: Pfizer, Maxime Dubois: None declared, Manuel F. Ugarte-Gil Speakers bureau: Janssen and Pfizer, Jérémy Fort: None declared, Luc PIJNENBURG: None declared, Aurore Chaudier: None declared, Lou Kawka: None declared, Charlotte Costecalde: None declared, Hugo Bergier: None declared, Emmanuel Chatelus: None declared, Rose-Marie Javier: None declared, Christelle Sordet: None declared, Jacques-Eric Gottenberg Speakers bureau: Pfizer and Astra-Zeneca, Jean Sibilia Speakers bureau: Pfizer, Yurilis Fuentes-Silva: None declared, Laurent Arnaud Speakers bureau: Pfizer and Astra-Zeneca.

Mortality risk in patients on hemodiafiltration versus hemodialysis: a 'real-world' comparison from the DOPPS

Background

With its convective component, hemodiafiltration (HDF) provides better middle molecule clearance compared with hemodialysis (HD) and is postulated to improve survival. A previous analysis of Dialysis Outcomes and Practice Patterns Study (DOPPS) data in 1998-2001 found lower mortality rates for high replacement fluid volume HDF versus HD. Randomized controlled trials have not shown uniform survival advantage for HDF; in secondary (non-randomized) analyses, better outcomes were observed in patients receiving the highest convection volumes.

Methods

In a 'real-world' setting, we analyzed patients on dialysis >90 days from seven European countries in DOPPS Phases 4 and 5 (2009-15). Adjusted Cox regression was used to study HDF (versus HD) and mortality, overall and by replacement fluid volume.

Results

Among 8567 eligible patients, 2012 (23%) were on HDF, ranging from 42% in Sweden to 12% in Germany. Median follow-up was 1.5 years during which 1988 patients died. The adjusted mortality hazard ratio (95% confidence interval) was 1.14 (1.00-1.29) for any HDF versus HD and 1.08 (0.92-1.28) for HDF >20 L replacement fluid volume versus HD. Similar results were found for cardiovascular and infection-related mortality. In an additional analysis aiming to avoid treatment-by-indication bias, we did not observe lower mortality rates in facilities using more HDF (versus HD).

Conclusions

Our results do not support the notion that HDF provides superior patient survival. Further trials designed to test the effect of high-volume HDF (versus lower volume HDF versus HD) on clinical outcomes are needed to adequately inform clinical practices.

Energyscapes and prey fields shape a North Atlantic seabird wintering hotspot under climate change

There is an urgent need for a better understanding of animal migratory ecology under the influence of climate change. Most current analyses require long-term monitoring of populations on the move, and shorter-term approaches are needed. Here, we analysed the ecological drivers of seabird migration within the framework of the energyscape concept, which we defined as the variations in the energy requirements of an organism across geographical space as a function of environmental conditions. We compared the winter location of seabirds with their modelled energy requirements and prey fields throughout the North Atlantic. Across six winters, we tracked the migration of 94 little auks (Alle alle), a key sentinel Arctic species, between their East Greenland breeding site and wintering areas off Newfoundland. Winter energyscapes were modelled with Niche Mapper™, a mechanistic tool which takes into account local climate and bird ecophysiology. Subsequently, we used a resource selection function to explain seabird distributions through modelled energyscapes and winter surface distribution of one of their main prey, Calanus finmarchicus. Finally, future energyscapes were calculated according to IPCC climate change scenarios. We found that little auks targeted areas with high prey densities and moderately elevated energyscapes. Predicted energyscapes for 2050 and 2095 showed a decrease in winter energy requirements under the high emission scenario, which may be beneficial if prey availability is maintained. Overall, our study demonstrates the great potential of the energyscape concept for the study of animal spatial ecology, in particular in the context of global change.

Microplastic pollution in the Greenland Sea: Background levels and selective contamination of planktivorous diving seabirds

Microplastics have been reported everywhere around the globe. With very limited human activities, the Arctic is distant from major sources of microplastics. However, microplastic ingestions have been found in several Arctic marine predators, confirming their presence in this region. Nonetheless, existing information for this area remains scarce, thus there is an urgent need to quantify the contamination of Arctic marine waters. In this context, we studied microplastic abundance and composition within the zooplankton community off East Greenland. For the same area, we concurrently evaluated microplastic contamination of little auks (Alle alle), an Arctic seabird feeding on zooplankton while diving between 0 and 50 m. The study took place off East Greenland in July 2005 and 2014, under strongly contrasted sea-ice conditions. Among all samples, 97.2% of the debris found were filaments. Despite the remoteness of our study area, microplastic abundances were comparable to those of other oceans, with 0.99 ± 0.62 m^-3 in the presence of sea-ice (2005), and 2.38 ± 1.11 m^-3 in the nearby absence of sea-ice (2014). Microplastic rise between 2005 and 2014 might be linked to an increase in plastic production worldwide or to lower sea-ice extents in 2014, as sea-ice can represent a sink for microplastic particles, which are subsequently released to the water column upon melting. Crucially, all birds had eaten plastic filaments, and they collected high levels of microplastics compared to background levels with 9.99 and 8.99 pieces per chick meal in 2005 and 2014, respectively. Importantly, we also demonstrated that little auks took more often light colored microplastics, rather than darker ones, strongly suggesting an active contamination with birds mistaking microplastics for their natural prey. Overall, our study stresses the great vulnerability of Arctic marine species to microplastic pollution in a warming Arctic, where sea-ice melting is expected to release vast volumes of trapped debris.

Front propagation speeds of T7 virus mutants

We propose a new reaction-diffusion model with an eclipse time to study the spread of viruses on bacterial populations. This new model is both biologically and physically sound, unlike previous ones. We determine important parameter values from experimental data, such as the one-step growth. We verify the proposed model by comparing theoretical and experimental data of the front propagation speed for several T7 virus strains.

Influence of ultrasound determination of fetal head position on mode of delivery: a pragmatic randomized trial

OBJECTIVE

To evaluate the influence of ultrasound determination of fetal head position on mode of delivery.

METHODS

This was a pragmatic open-label randomized controlled trial that included women with a singleton pregnancy in the vertex presentation at ≥ 37 weeks' gestation, cervical dilation ≥ 8 cm and who received epidural anesthesia. Women were assigned randomly to undergo either digital vaginal examination (VE group) or both digital vaginal and ultrasound examinations (VE+US group) to determine fetal head position. When the ultrasound and digital vaginal findings were inconsistent in the VE+US group, the ultrasound result was used for clinical management. The primary outcome assessed was operative delivery (Cesarean or instrumental vaginal delivery), and maternal and fetal morbidity were also assessed.

RESULTS

The VE and VE+US groups included 959 and 944 women, respectively. The overall rate of operative delivery was significantly higher in the VE+US group than in the VE group: 33.7% vs 27.1%, respectively (relative risk (RR), 1.24 (95% CI, 1.08-1.43)), as was the rate of Cesarean delivery: 7.8% vs 4.9%, respectively (RR, 1.60 (95% CI, 1.12-2.28)). The rate of instrumental vaginal delivery was also higher, albeit not significantly: 25.8% in the VE+US group vs 22.2% in the VE group (RR, 1.16 (95% CI, 0.99-1.37)). Neonatal outcomes did not differ between the two groups. When analysis was restricted to instrumental vaginal deliveries only, maternal and neonatal morbidity outcomes were similar in both groups.

CONCLUSION

Correction of fetal occiput position, determined initially by digital vaginal examination, using systematic ultrasound examination did not improve management of labor and increased the rate of operative delivery without decreasing maternal and neonatal morbidity.

Risk of hyperkalemia in patients with moderate chronic kidney disease initiating angiotensin converting enzyme inhibitors or angiotensin receptor blockers: a randomized study

Background

Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers are renoprotective but both may increase serum potassium concentrations in patients with chronic kidney disease (CKD). The proportion of affected patients, the optimum follow-up period and whether there are differences between drugs in the development of this complication remain to be ascertained.

Methods

In a randomized, double-blind, phase IV, controlled, crossover study we recruited 30 patients with stage 3 CKD under restrictive eligibility criteria and strict dietary control. With the exception of withdrawals, each patient was treated with olmesartan and enalapril separately for 3 months each, with a 1-week wash-out period between treatments. Patients were clinically assessed on 10 occasions via measurements of serum and urine samples. We used the Cochran–Mantel–Haenszel statistics for comparison of categorical data between groups. Comparisons were also made using independent two-sample t-tests and Welch’s t-test. Analysis of variance (ANOVA) was performed when necessary. We used either a Mann–Whitney or Kruskal-Wallis test if the distribution was not normal or the variance not homogeneous.

Results

Enalapril and olmesartan increased serum potassium levels similarly (0.3 mmol/L and 0.24 mmol/L respectively). The percentage of patients presenting hyperkalemia higher than 5 mmol/L did not differ between treatments: 37% for olmesartan and 40% for enalapril. The mean e-GFR ranged 46.3 to 48.59 ml/mint/1.73 m² in those treated with olmesartan and 46.8 to 48.3 ml/mint/1.73 m² in those with enalapril and remained unchanged at the end of the study. The decreases in microalbuminuria were also similar (23% in olmesartan and 29% in enalapril patients) in the 4 weeks time point. The percentage of patients presenting hyperkalemia, even after a two month period, did not differ between treatments. There were no appreciable changes in sodium and potassium urinary excretion.

Conclusions

Disturbances in potassium balance upon treatment with either olmesartan or enalapril are frequent and without differences between groups. The follow-up of these patients should include control of potassium levels, at least after the first week and the first and second month after initiating treatment.

Trial registration

The trial EudraCT “2008-002191-98”.

Worldwide, mortality risk is high soon after initiation of hemodialysis

Mortality rates for maintenance hemodialysis patients are much higher than the general population and are even greater soon after starting dialysis. Here we analyzed mortality patterns in 86,886 patients in 11 countries focusing on the early dialysis period using data from the Dialysis Outcomes and Practice Patterns Study, a prospective cohort study of in-center hemodialysis. The primary outcome was all-cause mortality, using time-dependent Cox regression, stratified by study phase adjusted for age, sex, race, and diabetes. The main predictor was time since dialysis start as divided into early (up to 120 days), intermediate (121-365 days), and late (over 365 days) periods. Mortality rates (deaths/100 patient-years) were 26.7 (95% confidence intervals 25.6-27.9), 16.9 (16.2-17.6), and 13.7 (13.5-14.0) in the early, intermediate, and late periods, respectively. In each country, mortality was higher in the early compared to the intermediate period, with a range of adjusted mortality ratios from 3.10 (2.22-4.32) in Japan to 1.15 (0.87-1.53) in the United Kingdom. Adjusted mortality rates were similar for intermediate and late periods. The ratio of elevated mortality rates in the early to the intermediate period increased with age. Within each period, mortality was higher in the United States than in most other countries. Thus, internationally, the early hemodialysis period is a high-risk time for all countries studied, with substantial differences in mortality between countries. Efforts to improve outcomes should focus on the transition period and the first few months of dialysis.

Reduced survival and quality of life following return to dialysis after transplant failure: the Dialysis Outcomes and Practice Patterns Study

BACKGROUND

Although dialysis after kidney transplant failure (TF) is common, the outcomes of these patients remain unclear. We compared outcomes of TF patients with transplant-naïve (TN) patients wait-listed for kidney transplantation.

METHODS

We used data from the Dialysis Outcomes and Practice Patterns Study (DOPPS), including laboratory markers and health-related quality of life (HR-QOL). Mortality and hospitalization of participants with one prior TF versus TN patients were compared using the Cox regression analysis. HR-QOL physical and mental component summary scores (PCS and MCS) were examined using linear mixed models, and clinical practices were compared using logistic regression.

RESULTS

Compared with TN patients (n = 2806), TF patients (n = 1856) were younger (48 versus 51 years, P = 0.003), less likely to be diabetic (18 versus 27%, P < 0.0001) and to use a permanent surgical vascular access {adjusted odds ratio (AOR): 0.85 [95% confidence interval (CI): 0.70-1.03], P = 0.10}, particularly within the first 3 months after TF [AOR 0.45 (0.32-0.62), P < 0.0001]. TF patients also had lower PCS [mean difference -2.56 (-3.36, -1.75), P < 0.0001] but not MCS [-0.42 (-1.34, 0.50), P = 0.37]. All-cause mortality [adjusted hazard ratio (AHR): 1.32 (95% CI: 1.05-1.66), P = 0.02], especially infection-related [AHR 2.45 (95% CI: 1.36-4.41), P = 0.01], was higher among TF patients.

CONCLUSIONS

TF patients have reduced QOL and higher mortality, particularly due to infections, than TN patients. Interventions to optimize care before and after starting dialysis remain to be identified and applied in clinical practice.

Effect of a plasma sodium biofeedback system applied to HFR on the intradialytic cardiovascular stability. Results from a randomized controlled study

Background

Intradialytic hypotension (IDH) is still a major clinical problem for haemodialysis (HD) patients. Haemodiafiltration (HDF) has been shown to be able to reduce the incidence of IDH.

Methods

Fifty patients were enrolled in a prospective, randomized, crossover international study focussed on a variant of traditional HDF, haemofiltration with endogenous reinfusion (HFR). After a 1-month run-in period on HFR, the patients were randomized to two treatments of 2 months duration: HFR (Period A) or HFR-Aequilibrium (Period B), followed by a 1-month HFR wash-out period and then switched to the other treatment. HFR-Aequilibrium (HFR-Aeq) is an evolution of the haemofiltration with endogenous reinfusion (HFR) dialysis therapy, with dialysate sodium concentration and ultrafiltration rate profiles elaborated by an automated procedure. The primary end point was the frequency of IDH.

Results

Symptomatic hypotension episodes were significantly lower on HFR-Aeq versus HFR (23 ± 3 versus 31 ± 4% of sessions, respectively, P l= l0.03), as was the per cent of clinical interventions (17 ± 3% of sessions with almost one intervention on HFR-Aeq versus 22 ± 2% on HFR, P <0.01). In a post-hoc analysis, the effect of HFR-Aeq was greater on more unstable patients (35 ± 3% of sessions with hypotension on HFR-Aeq versus 71 ± 3% on HFR, P <0.001). No clinical or biochemical signs of Na/water overload were registered during the treatment with HFR-Aeq.

Conclusions

HFR-Aeq, a profiled dialysis supported by the Natrium sensor for the pre-dialysis Na⁺ measure, can significantly reduce the burden of IDH. This could have an important impact in every day dialysis practice.

Baseline characteristics of an incident haemodialysis population in Spain: results from ANSWER--a multicentre, prospective, observational cohort study

BACKGROUND

The ANSWER study aims to identify risk factors leading to increased cardiovascular morbidity and mortality in a Spanish incident haemodialysis population. This paper summarizes the baseline characteristics of this population.

METHODS

A prospective, observational, one-cohort study, including all consecutive incident haemodialysis patients from 147 Spanish nephrology services, was conducted. Patients were enrolled between October 2003 and September 2004. Sociodemographic, clinical, laboratory and health care characteristics were collected.

RESULTS

Baseline characteristics are described for 2341 incident haemodialysis patients [mean (SD) age 65.2 (14.5) years, 63% males]. The main cause of renal failure was diabetic nephropathy (26%). The majority of patients (57%) had a Karnofsky score of 80-100 and 27% were followed up by a nephrologist for 500 ng/ml, 41% and saturated transferrin <20 or >40%, 50%) despite previous treatment with erythropoiesis-stimulating agents in 41% of cases.

CONCLUSIONS

There is excessive use of temporary catheters and a high prevalence of uraemia-related cardiovascular risk factors among incident haemodialysis patients in Spain. The poor control of hypertension, anaemia, malnutrition and mineral metabolism and late referral to a nephrologist indicate the need for improving the therapeutic management of patients before the onset of haemodialysis.

Rosai-Dorfman disease following bone marrow transplantation for pre-B cell acute lymphoblastic leukemia

A child with acute pre-B cell lymphoblastic leukemia underwent haploidentical bone marrow transplantation (BMT) after first relapse. Approximately 8 months after the BMT, he developed a soft tissue mass overlying a defect in the left frontal bone. He was found to have several additional osteolytic lesions but no evidence of lymphadenopathy or organomegaly. A biopsy of the presenting lesion demonstrated a polymorphous infiltrate composed predominantly of S-100 protein and CD68 immunoreactive histiocytic cells. Together with the presence of emperipolesis, the process was interpreted as Rosai-Dorfman (R-D) disease. He received chemotherapy with vinblastine, prednisone, 6-mercaptopurine and methotrexate and has been in remission for over 4 years. Only one previous example of acute lymphoblastic leukemia in childhood has been reported with R-D disease.

Chronic renal failure: a cardiovascular risk factor

The risk of developing cardiovascular disease is greatly increased in patients undergoing renal replacement therapy and, notably, morbidity and mortality due to therapy is much higher in these patients than in the general population. Minimal alterations in renal function, as evidenced by reduced glomerular filtration rate and the presence of albuminuria, have been described as potent cardiovascular risk factors. The classic risk factors only partly explain this difference; hence, we must admit the existence of known and emerging factors associated with increased cardiovascular risk in patients with renal disease. This article provides a review of these factors. It describes the role of hyperphosphoremia and elevated calcium-phosphorous product in the formation of cardiovascular calcifications, the contribution of anemia to left ventricular hypertrophy, and the consequences of accelerated atherogenesis with oxidative stress and a microinflammatory state resulting from endothelial dysfunction. Hyperhomocysteinemia, increased sympathetic nervous system activity, lipoprotein alterations with elevated lipoprotein A, and increases in the concentrations of asymmetrical dimethyl-arginine are other examples of the changes described in this population. Patients with renal disease should be considered to be at high risk for developing cardiovascular disease and candidates for implementation of secondary prevention strategies. It is for this reason that early identification of renal failure, which remains hidden in many cases, is of prime importance.

Fronts with continuous waiting-time distributions: theory and application to virus infections

We generalize to arbitrary waiting-time distributions some results which were previously derived for discrete distributions. We show that for any two waiting-time distributions with the same mean delay time, that with higher dispersion will lead to a faster front. Experimental data on the speed of virus infections in a plaque are correctly explained by the theoretical predictions using a Gaussian delay-time distribution, which is more realistic for this system than the Dirac delta distribution considered previously [J. Fort and V. Méndez, Phys. Rev. Lett. 89, 178101 (2002)].

[Compliance with the 2002 consensus document of the Spanish Society of Nephrology for the control of diabetic nephropathy in Catalonia (ECCODIAB)]

OBJECTIVE

To evaluate the level of compliance with the 2002 consensus document (Spanish Society of Nephrology) on guidelines for the detection, prevention and treatment of diabetic nephropathy in Catalonia.

SUBJECTS AND METHODS

Multicenter (23 hospitals), observational, cross-sectional, descriptive study conducted in 413 diabetic patients (61.7% men, 38.3% women) with a median age of 66.2 +/-11.5 years (26-93 years). The ANOVA test (post-hoc analysis; p value< 0.05) was used to study the relationships between the stages of diabetic nephropathyand different variables.

RESULTS

90.3% of the patients had type 2 DM. The following anthropometric parameters were observed: BMI 29.8 +/- 5 kg/m2 (BMI > 30 kg/m2: 48.7%) and waist circumference 104.1 +/- 14 cm (48.6% men > 102 cm and 78.9% women > 88 cm). Serum creatinine 1.9 +/- 1.3 mg/dl and simplified MDRD equation 45.3 +/- 25.0 ml/min/1.73 m2 [65.8%with CKD stages 3 and 4]. 80% of patients had ophthalmologic examination and 52.8% antiplatelet treatment. Hb A1c was 7.3 +/- 1.3%, but the percentage of patients with glycated hemoglobin > 7% and 8% was 54.9 and 28.6% [only 50.2% had been seen by an endocrinologist in the last 6 months]. 52.8% of patients were treated with insulin and 44.1% with anti-diabetic drugs, although only 19.6% used the new anti-diabetic drugs. 61% of patients had an LDLc > 100 mg/dl (61% treated) and 44% had triglycerides (TG) > 150 mg/dl (72% treated). 95% of patients presented with hypertension (BP > or = 130/80 mmHg),91% were undergoing antihypertensive treatment (79.7% with angiotensin-converting enzyme inhibitors and / or angiotensin receptor blockers). 81% with microalbuminuria and 78%with established proteinuria were receiving anti-proteinuric treatment. Of the patients considered to be refractory to BP (>3 drugs), only 28.9% underwent ambulatory BP monitoring. Significant differences were observed between stages of diabetic nephropathy and glycated hemoglobin (HBA1c; p = 0.048), systolic blood pressure (SBP; p = 0.024), lipidic control (HDLc; p = 0.015 and TG; p = 0.034), anemia (Hb; p = 0.010) and CKD (creatinine and sMDRD; p = 0.000). The levels of compliance with the therapeutic objectives regarding lipid control (LDL < or = 100 mg/dl and TG< or = 150 mg/dl), BP < or = 130/80 mmHg and HbA1c < or =7% were 1 objective: 68%, 2 objectives: 21.8% and 3 objectives: only 4% of patients.

CONCLUSIONS

According to the results of our study, only a reduced proportion of patients fulfilled the different therapeutic end-points indicated. Future measures will be directed at improving physician-patient relationships with the main aim of intensifying the therapeutic measures to attain better metabolic and blood pressure control, nephroprotection and prevention in the appearance of cardiovascular events.

Psychosocial Factors and Health-Related Quality of Life in Hemodialysis Patients

Several sociodemographic and clinical variables are known to influence the health-related quality of life (HRQOL) of patients with kidney disease, yet the relationship between psychological factors and the HRQOL measured by the Kidney Disease Quality of Life Short-Form (KDQOL-SF) is incompletely understood. The objective of this study was to examine the relationship between psychosocial status (depressive symptoms, trait anxiety, and social support) and KDQOL-SF scales in hemodialysis (HD) patients by controlling the effects of sociodemographic and clinical variables. The HRQOL of 194 patients from 43 dialysis centers in Spain was assessed by completing the KDQOL-SF, and evaluating depressive Symptoms (Cognitive Depression Index), trait anxiety (Trait Anxiety Inventory) and degree of social support (Scale of Perceived Social Support). We also recorded several sociodemographic and clinical variables. Two regression models were estimated for each of the 19 scales in the KDQOL-SF. In the first model, we only included sociodemographic and clinical-factors, while the second model also took into consideration psychosocial variables. These last factors (trait anxiety and depressive symptoms, not social support) were found to increase the proportion of explained variability, with highest standardized regression coefficients observed for most KDQOL-SF scales. Depressive symptoms were related to a poor HRQOL when there was a strong physical component, while trait anxiety was mainly related to emotional upset and social relationships. We were able to conclude that trait anxiety and depressive symptoms are strongly associated with the HRQOL assessed by the KDQOL-SF in HD patients. The effects of these factors should therefore be considered when evaluating the quality of life of this type of patient.

Psychosocial factors and quality of life in young hemodialysis patients with low comorbidity

BACKGROUND

The current predominance of older patients, diabetic patients and high-comorbidity patients among the hemodialysis (HD) population has probably influenced the definition of the effects of renal disease on health-related quality of life (HRQOL), and these effects can be different in the patient subgroup without these characteristics. This multicenter study aimed to assess HRQOL in non-diabetic HD patients, aged < 65 yrs and with low comorbidity, and to study the effects of the demographic, clinical and psychosocial characteristics on their HRQOL.

METHODS

117 patients from 43 Spanish HD centers participated in the study. Patients completed the Kidney Disease Quality of Life Short-Form questionnaire (KDQOL-SF) and screening for depressive symptoms, anxiety symptoms and social support. Various sociodemographic and clinical variables were also recorded.

RESULTS

HD patients' HRQOL showed a profile similar to that of the general HD population, with low physical health scores, but normal mental health scores. Multivariate analysis demonstrated that gender, older age, non-working status, low social support and low levels of hemoglobin (Hb), Kt/V or protein catabolic rate (PCR), had a negative effects, but these effects were of relatively small magnitude and appeared only in some scales. The most important independent predictors of HRQOL were anxiety state and depressive symptoms.

CONCLUSIONS

In non-diabetic HD patients, aged < or = 65 yrs and with low comorbidity, psychological factors (anxiety state and depressive symptoms) are crucial HRQOL determinants. These variables should be considered when assessing HRQOL in HD patients with these demographic and clinical characteristics.

Advantages of Sabatier for extended duration manned missions

As manned space missions become longer and go farther away (i.e., Mars missions), the cost of resupply missions becomes substantial and even impractical. In order to reduce the logistics penalty for air revitalization in manned spacecraft, breathing oxygen (O2) must be recovered from metabolic carbon dioxide (CO2). The Sabatier CO2 reduction system is a key component of an integrated air revitalization system. The heart of the Sabatier system is the chemical catalyst bed that reacts carbon dioxide with hydrogen to form methane and water. Product water from a Sabatier subsystem would positively affect the current International Space Station (ISS) water balance and Mars missions would also benefit from the use of product methane as a propellant. This article focuses on the potential benefits of using the Sabatier subsystem for ISS and potential Mars mission applications.

Circulating levels of plasminogen activator inhibitor type-1, tissue plasminogen activator, and thrombomodulin in hemodialysis patients: biochemical correlations and role as independent predictors of coronary artery stenosis

This study investigated the relationship between the circulating levels of the endothelial cell glycoproteins plasminogen activator inhibitor type 1 (PAI-1), tissue plasminogen activator (TPA), and thrombomodulin (TM) and the major vascular risk factors described in dialysis patients. In addition, the role of these endothelial cell products as independent predictors of coronary artery disease (CAD) was analyzed. Levels of TM, TPA antigen (Ag), TPA activity, PAI-1 Ag, PAI-1 activity, TPA/PAI complexes, thrombin-antithrombin complexes, fibrinopeptide A, C-reactive protein (CRP), interleukin-1beta and tumor necrosis factor-alpha, lipids, apoproteins A1 and B, and albumin were measured in a group of 200 nondiabetic dialysis patients and 100 healthy matched volunteers. When compared with healthy controls, dialysis patients showed increased levels of CRP, TM, TPA, and PAI-1 and evidence of increased thrombin-dependent fibrin formation. Increased levels of active PAI-1 were associated to a great extent with major classic vascular risk factors and to a lesser extent with CRP and serum triglycerides. Forty-six patients (23%) had evidence of CAD. Variables associated with CAD in the univariate analysis included age, time on dialysis, male gender, number of packs of cigarettes per year, high BP, fibrinogen, apolipoprotein B, albumin, PAI-1 activity, CRP, thrombin-antithrombin complexes, and fibrinopeptide A. Logistic regression analysis found age, high-density lipoprotein cholesterol, gender, high BP, CRP, time on dialysis, and PAI-1 activity to be independent predictors of CAD. This model classified correctly 85% of patients as having CAD and showed adequate goodness of fit for all risk categories. Our data support a pathogenic link among activated inflammatory response, endothelial injury, and CAD in hemodialysis patients and suggest that assessment of circulating PAI-1 levels could be an additional tool to identify dialysis patients who are at risk for developing atheromatous cardiovascular disease.

[Rapid-detection GBM-ANCA ELISA. An emergency tool for the early diagnosis of type I and II rapidly progressive glomerulonephritis]

Rapidly progressive glomerulonephritides (RPGN) are forms of necrotizing glomerulonephritis associated with anti-glomerular basement membrane (anti-GBM) and anti-neutrophil cytoplasmic antibodies (ANCA) against the antigens proteinase-3 (anti-PR3) and myeloperoxidase (anti-MPO). RPGN have a course of rapid progression to renal failure. We compared the results from the semiquantitative ELISAs for anti-GMB antibodies, PR3-ANCA and MPO-ANCA and the indirect immunofluorescence technique (IIF) against a new rapid assay (30 minutes) for the same antibodies in patients with clinically suspected RPGN. The semiquantitative ELISAs for anti-GBM antibodies and PR3-ANCA and MPO-ANCA have a proven diagnostic significance in patients with RPGN I and III. There were no significant differences between the ANCA-GBM screening test and the results from the semiquantitative ELISAs (p > 0.05). We did not find significant differences between the results for PR3-ANCA and MPO-ANCA from the ANCA-GBM screening test with C-ANCA and P-ANCA IIF values (p > 0.05). We also corroborated that the ANCA-GBM screening test is a diagnostic tool for RPGN I and III as useful as the semiquantitative ELISAs and the IFF technique. The ANCA-GBM ELISA screening test is a tool as useful as the semiquantitative ELISA against anti-GBM antibodies for diagnosis of RPGN I. The comparison of the screening ELISA with the IIF technique and the semiquantitative ELISAs against PR3-ANCA and MPO-ANCA showed similar utility for diagnosis of RPGN III. The advantages of the new screening assay are that three antibodies are tested at the same time, yielding results in only 30 minutes.

Speed of reaction-transport processes

We present an approach to determining the speed of wave-front solutions to reaction-transport processes. This method is more accurate than previous ones. This is explicitly shown for several cases of practical interest: (i) the anomalous diffusion reaction, (ii) reaction diffusion in an advective field, and (iii) time-delayed reaction diffusion. There is good agreement with the results of numerical simulations.

A randomized, double-blind, crossover clinical trial of diclofenac plus misoprostol versus acetaminophen in patients with osteoarthritis of the hip or knee

OBJECTIVE

To perform a randomized, double-blind, crossover clinical trial of diclofenac + misoprostol versus acetaminophen in ambulatory patients with osteoarthritis of the hip or knee.

METHODS

Patients in 12 ambulatory care settings were eligible if they were age >40 years and if they had Kellgren/Lawrence radiographic grade 2-4 osteoarthritis of the knee or hip and a score of > or =30 mm on a 100-mm visual analog pain scale. Patients were randomized to one of two groups, 75 mg diclofenac + 200 microg misoprostol twice daily or 1,000 mg acetaminophen 4 times daily (each for 6 weeks), and were then crossed over to the other treatment for 6 weeks. A placebo was included in each treatment regimen to enable double blinding. The primary outcome measures were the Western Ontario and McMaster Universities Osteoarthritis Index and the visual analog pain scale of the Multidimensional Health Assessment Questionnaire. Safety was assessed using a standard form to review adverse events.

RESULTS

We enrolled 227 patients, of whom 218 provided data for the first treatment period and 181 provided data for both treatment periods. Significantly higher levels of improvement in the primary outcomes were seen for diclofenac + misoprostol than for acetaminophen (P < 0.001). Adverse events were more common when patients took diclofenac + misoprostol (P = 0.046). Diclofenac + misoprostol was rated as "better" or "much better" by 57% of the 174 patients who provided such ratings for both treatment periods, while acetaminophen was rated as "better" or "much better" by 20% of these patients, and 22% reported no difference (P < 0.001). Differences favoring diclofenac + misoprostol over acetaminophen were greater in patients with more severe osteoarthritis according to baseline pain scores, radiographs, or number of involved joints.

CONCLUSION

Patients with osteoarthritis of the hip or knee had significantly greater improvements in pain scores over 6 weeks with diclofenac + misoprostol than with acetaminophen, although patients with mild osteoarthritis had similar improvements with both drugs. Acetaminophen was associated with fewer adverse events.

Equilibrium of drops on inclined hydrophilic surfaces

Why does not gravity make drops slip down the inclined surfaces, e.g., plant leaves? The current explanation is based on the existence of surface inhomogeneities, which cause a sustaining force that pins the contact line. Following this theory, the drop remains in equilibrium until a critical value of the sustaining force is reached. We propose an alternative analysis, from the point of view of energy balance, for the particular case in which the drop leaves a liquid film behind. The critical angle of the inclined surface at which the drop slips down is predicted. This result does not depend explicitly on surface inhomogeneities, but only on the drop size and surface tensions. There is good agreement with experiments for contact angles below 90 degrees where the formation of the film is expected, whereas for greater contact angles great discrepancies arise.

Spleno-renal shunt blood flow is an accurate index of collateral circulation in different models of portal hypertension and after pharmacological changes in rats

BACKGROUND/AIMS

Recently, we developed a new method to measure collateral blood flow in rats: splenorenal shunt (SRS) blood flow (BF). The aims were to evaluate the reproducibility of SRSBF measurement in different models of portal hypertension, and to investigate the ability of SRSBF to disclose pharmacological changes.

METHODS

Hemodynamics were determined in anesthetized rats with secondary biliary, CCl4 or DMNA cirrhosis and portal vein ligation (PVL) under baseline and pharmacological (octreotide, vapreotide) conditions. The main measurements performed were: SRSBF by the transit time ultrasound (TTU) method and % portosystemic shunts (PSS) by the microsphere method.

RESULTS

SRSBF was 6 to 10 times higher in portal hypertensive rats and was similar in the different models of cirrhosis but was higher in portal vein ligated rats than in cirrhotic rats (1.1+/-0.7 vs 0.6+/-0.7 ml x min(-1) x 100 g(-1), p=0.01). SRSBF was correlated with mesenteric %PSS (r=0.61, p<0.01), splenic %PSS (r=0.54, p<0.05), portal pressure (r= 0.32, p<0.05) and the area of liver fibrosis (r=0.33, p<0.05). Octreotide significantly decreased SRSBF (-23+/-20%, p<0.01 vs placebo: -6+/-8%, NS). Vapreotide significantly decreased SRSBF but not mesenteric or splenic %PSS compared to placebo. The variations in SRSBF (-26+/-32%) and in splenic %PSS (0+/-15%) with vapreotide were significantly different (p<0.05) and not correlated (r=-0.1, NS).

CONCLUSIONS

Determination of SRSBF by TTU is an accurate way to measure collateral blood flow in different models of intra- and extra-hepatic portal hypertension in rats. Its sensitivity provides accurate measurement of pharmacological changes, unlike the traditional estimation of %PSS by the microsphere method.

Speed of wave-front solutions to hyperbolic reaction-diffusion equations

The asymptotic speed problem of front solutions to hyperbolic reaction-diffusion (HRD) equations is studied in detail. We perform linear and variational analyses to obtain bounds for the speed. In contrast to what has been done in previous work, here we derive upper bounds in addition to lower ones in such a way that we can obtain improved bounds. For some functions it is possible to determine the speed without any uncertainty. This is also achieved for some systems of HRD (i.e., time-delayed Lotka-Volterra) equations that take into account the interaction among different species. An analytical analysis is performed for several systems of biological interest, and we find good agreement with the results of numerical simulations as well as with available observations for a system discussed recently.

Irreversible thermodynamics of Poisson processes with reaction

A kinetic model is derived to study the successive movements of particles, described by a Poisson process, as well as their generation. The irreversible thermodynamics of this system is also studied from the kinetic model. This makes it possible to evaluate the differences between thermodynamical quantities computed exactly and up to second-order. Such differences determine the range of validity of the second-order approximation to extended irreversible thermodynamics.

Reaction-diffusion waves of advance in the transition to agricultural economics

In a previous paper [J. Fort and V. Méndez, Phys. Rev. Lett. 82, 867 (1999)], the possible importance of higher-order terms in a human population wave of advance has been studied. However, only a few such terms were considered. Here we develop a theory including all higher-order terms. Results are in good agreement with the experimental evidence involving the expansion of agriculture in Europe.

Celecoxib, a COX-2--specific inhibitor: the clinical data

Celecoxib offers the unique therapeutic prospect of alleviating pain and inflammation without the untoward gastrointestinal, renal, and platelet effects associated with conventional nonsteroidal anti-inflammatory drugs. This is possible because celecoxib is a cyclooxygenase-2 (COX-2)-specific inhibiting agent that inhibits the conversion of arachidonic acid to the prostaglandins that mediate pain and inflammation while having no effect on the formation of the prostaglandins that mediate normal homeostasis in the gastrointestinal tract, kidneys, and platelets and that are formed under the control of cyclooxygenase-1 (COX-1). Double-blind clinical trials have demonstrated that celecoxib is as effective in ameliorating the signs and symptoms of osteoarthritis and rheumatoid arthritis as naproxen and as effective as aspirin in reducing pain following dental extraction. Controlled trials have also shown that the incidence of gastroduodenal ulcers and the combined incidence of gastroduodenal ulcers and erosions are significantly lower with celecoxib therapy than with naproxen therapy and are similar to those associated with placebo administration. In a study of platelet function, it was found that a single 650-mg dose of aspirin profoundly diminished platelet function, while therapeutic doses of celecoxib exhibited no such effect. Celecoxib has been shown to be well tolerated, with incidences of adverse events similar to placebo in most instances. In summary, evidence to date indicates that celecoxib is a safe and effective therapeutic modality for the management of arthritis and pain.

[Budd-Chiari syndrome due to membranous obstruction of the inferior vena cava of congenital origin. Ten-year follow-up after radiologic treatment]

We report a case of Budd-Chiari syndrome due to membranous obstruction of the inferior vena cava with a congenital malformation composed of a left inferior vena cava at the sub-renal level with an azygo-caval continuation without a retrohepatic segment of the inferior vena cava. To our knowledge, this is the first report of this association. The congenital venous malformation suggests a congenital etiology to the inferior vena cava membrane. The membranous obstruction was treated by percutaneous transluminal angioplasty. During the 10-year follow-up, there was no recurrence of the membranous obstruction as seen with Doppler ultrasound and magnetic resonance imaging.