Biostabilization and erodibility of cohesive sediment deposits in wildfire-affected streams

The erosion characteristics and bed stability of wildfire-affected stream sediment were measured in an annular flume. Biofilms were grown in the flume on cohesive streambed sediments collected from a wildfire affected stream and a reference undisturbed stream in southern Alberta, Canada. Examined factors that influence sediment erosion, settling and bed stability included applied shear stress, geochemical and physical properties of the sediment, floc structural characteristics and consolidation period (2, 7, 14 days). Erosion characteristics and sediment properties were strongly influenced by wildfire, consolidation period and bed biostabilization. The fire-modified sediment was more resistant to erosion than the reference unburned sediment. Settling velocities were lower in the burned sediment due to higher organic content and porosity. The critical shear stresses for erosion were 1.6 and 1.8 times higher for the burn-associated sediment after 7 and 14 days of consolidation. The differences are related to the greater degree and spatial extent (depth) of biofilm attachment in the burned sediment. Erosion depths were 4-8 times higher in burned sediment as a result of wildfire-associated biostabilization.

Impaired functional capacity is associated with all-cause mortality after major elective intra-abdominal surgery

BACKGROUND

Studies of preoperative cardiopulmonary exercise testing (CPET) have shown that a reduced oxygen uptake at anaerobic threshold (AT) and elevated ventilatory equivalent for carbon dioxide (VE/VCO(2)) were associated with reduced short- and medium-term survival after major surgery. The aim of this study was to determine the relative values of these, and also clinical risk factors, in identifying patients at risk of death after major intra-abdominal, non-vascular surgery.

METHODS

Patients aged >55 yr, undergoing elective colorectal resection, radical nephrectomy, or cystectomy between June 2004 and May 2009 had CPET during their routine pre-assessment clinic visit. We performed a retrospective analysis of known clinical risk factors and data from CPET to assess their relationship to all-cause mortality after surgery.

RESULTS

Eight hundred and forty-seven patients underwent surgery, of whom 18 (2.1%) died. A clinical history of ischaemic heart disease (RR 3.1, 95% CI 1.3-7.7), a VE/VCO(2) >34 (RR 4.6, 95% CI 1.4-14.8), and an AT < or =10.9 ml kg(-1) min(-1) (RR 6.8, 95% CI 1.6-29.5) were all significant predictors of all-cause hospital and 90 day mortality. The effect of reduced AT was most pronounced in patients with no history of cardiac risk factors (RR 10.0, 95% CI 1.7-61.0).

CONCLUSIONS

The routine measurement of AT and VE/VCO(2) using CPET for patients undergoing high-risk surgery can accurately identify the majority of high-risk patients, while the use of clinical risk factors alone will only identify a relatively small proportion of at-risk patients.

Gene expression in histologically normal epithelium from breast cancer patients and from cancer-free prophylactic mastectomy patients shares a similar profile

INTRODUCTION

We hypothesised that gene expression in histologically normal (HN) epithelium (NlEpi) would differ between breast cancer patients and usual-risk controls undergoing reduction mammoplasty (RM), and that gene expression in NlEpi from cancer-free prophylactic mastectomy (PM) samples from high-risk women would resemble HN gene expression.

METHODS

We analysed gene expression in 73 NlEpi samples microdissected from frozen tissue. In 42 samples, we used microarrays to compare gene expression between 18 RM patients and 18 age-matched HN (9 oestrogen receptor (ER)+, 9 ER-) and 6 PM patients. Data were analysed using a Bayesian approach (BADGE), and validated with quantitative real-time PCR (qPCR) in 31 independent NlEpi samples from 8 RM, 17 HN, and 6 PM patients.

RESULTS

A total of 98 probe sets (86 genes) were differentially expressed between RM and HN samples. Performing hierarchical analysis with these 98 probe sets, PM and HN samples clustered together, away from RM samples. qPCR validation of independent samples was high (84%) and uniform in RM compared with HN patients, and lower (58%), but more heterogeneous, in RM compared with PM patients. The 86 genes were implicated in many processes including transcription and the MAPK pathway.

CONCLUSION

Gene expression differs between the NlEpi of breast cancer cases and controls. The profile of cancer cases can be discerned in high-risk NlEpi from cancer-free breasts. This suggests that the profile is not an effect of the tumour, but may mark increased risk and reveal the earliest genomic changes of breast cancer.

Clinical, molecular and epidemiological description of a cluster of community-associated methicillin-resistant Staphylococcus aureus isolates from injecting drug users with bacteraemia

Community-associated methicillin-resistant Staphylococcus aureus (CA-MRSA) is an increasing problem, predominantly in previously healthy individuals including notable risk groups such as the homeless, those who play close-contact sports, military personnel, men who have sex with men (MSM) and injecting drug users (IDUs). Over a 5-month period, four IDUs were admitted to Addenbrooke's Hospital, Cambridge, UK, with MRSA bacteraemia. All four patients presented with complex clinical features, with more than one focus of infection, and were linked epidemiologically. The atypical antibiogram of the MRSA isolates (ciprofloxacin-susceptible) prompted further characterization, both phenotypically (antibiotic resistance typing; phage typing) and genotypically (detection of toxin genes by PCR; pulsed-field gel electrophoresis (PFGE); Staphylococcal chromosome cassette (SCC) mec typing; multi-locus sequence typing (MLST)). All four isolates had similar antibiograms, were Panton-Valentine Leucocidin (PVL) toxin gene-negative, harboured SCCmec type IV and were closely related as shown by phage typing and PFGE. These isolates were representatives of a community-associated clone, ST1-MRSA-IV, known to be circulating in IDUs in the UK since 2001. This paper presents a detailed description of the clinical, microbiological and epidemiological features of a series of CA-MRSA bacteraemias in IDUs in the UK.

Comparison of wear of ultra-high molecular weight polyethylene acetabular cups against surface-engineered femoral heads

Alumina ceramic heads have been previously shown to reduce polyethylene wear in comparison to cobalt chrome (CoCr) heads in artificial hip joints. However, there are concerns about the brittle nature of ceramics. It is therefore of interest to investigate ceramic-like coatings on metallic heads. The aim of this study was to compare the friction and wear of ultra-high molecular weight polyethylene (UHMWPE) against alumina ceramic, CoCr, and surface-engineered ceramic-like coatings in a friction simulator and a hip joint simulator. All femoral heads tested were 28 mm diameter and included: Biolox Forte alumina, CoCr, arc evaporative physical vapour deposition (AEPVD) chromium nitride (CrN) coated CoCr, plasma-assisted chemical vapour deposition (PACVD) amorphous diamond-like carbon (aDLC) coated CoCr, sputter CrN coated CoCr, reactive gas controlled arc (RGCA) AEPVD titanium nitride (TiN) coated CoCr, and Graphit-iC coated CoCr. These were articulated against UHMWPE acetabular cups in a friction simulator and a hip joint simulator. Alumina and CoCr gave the lowest wear volumes whereas the sputter coated CrN gave the highest. Alumina also had the lowest friction factor. There was an association between surface parameters and wear. This study indicates that surface topography of surface-engineered femoral heads is more important than friction and wettability in controlling UHMWPE wear.

Phase II study of calcitriol-enhanced docetaxel in patients with previously untreated metastatic or locally advanced pancreatic cancer

PURPOSE

To determine the safety and efficacy of weekly high-dose oral calcitriol and docetaxel, given to patients with non-resectable, incurable pancreatic cancer.

PATIENTS AND METHODS

Twenty-five patients were enrolled onto this phase II study. Patients were treated with oral calcitriol 0.5 microg/kg on day 1, followed by docetaxel 36 mg/m(2) IV on day 2, administered weekly for three consecutive weeks, followed by 1 week without treatment. Patients followed a low-calcium diet and increased their hydration. The primary end-point of the trial was time-to-progression.

RESULTS

Three of 25 patients attained a partial response (12%, 95% CI 3 to 31) and seven (28%) achieved stable disease. Median time-to-progression was 15 weeks, and median overall survival was 24 weeks. Toxicities observed (hyperglycemia, fatigue) were mostly attributable to the docetaxel or its pre-treatment.

CONCLUSIONS

This regimen of high-dose calcitriol with docetaxel may have activity in incurable pancreatic cancer, with a modest increase in TTP when compared to historical findings using single-agent docetaxel. However, results do not appear superior to those seen with gemcitabine, with or without erlotinib.

Dissemination and evaluation of the ASAS/EULAR recommendations for the management of ankylosing spondylitis: results of a study among 1507 rheumatologists

Background:

Ten ASAS/EULAR recommendations for the management of ankylosing spondylitis (AS) were published in 2006.

Objectives:

(a) To disseminate and (b) to evaluate conceptual agreement with, and (c) application of, these recommendations as well as (d) potential barriers to the application.

Methods:

A questionnaire was sent to rheumatologists in 10 countries. It included (a) the text of the recommendations; (b) rheumatologists’ demographic variables; (c) two numerical rating scales from 1 to 10 for each recommendation: conceptual agreement with, and application of, the recommendation (10 indicates maximal agreement and maximal application); and (d) a list of potential barriers to the application of the recommendation. Statistical analysis included descriptive and multivariate analyses.

Results:

7206 questionnaires were sent out; 1507 (21%) were returned. Of the 1507 answering rheumatologists, 62% were men, mean (SD) age 49 (9) years, and 34% had an academic position. Conceptual agreement with the recommendations was high (mean (SD) for all recommendations 8.9 (0.9)). Self-reported application was also high (8.2 (1.0)). The difference between agreement and application varied across recommendations and countries. The most pronounced discrepancies were reported for use of anti-tumour necrosis factor drugs in a few countries, with funding as the most commonly reported barrier for application of this recommendation.

Conclusion:

This large project has helped the dissemination of the ASAS/EULAR recommendations for the management of AS and shows that conceptual agreement with the recommendations is very high. The project also highlights inequalities in access to healthcare for European citizens with AS.

Comparison of speech production in upright and supine position

Speech is usually produced in an upright sitting or standing posture. Measurements and judgments of speech may be made in conditions requiring a supine position, however. These conditions include MRI recordings, and oral procedures, such as, adjustments to dental appliances, medical and surgical procedures. It is of interest, therefore, to see whether gravity has strong or systematic effects on tongue behavior. In the present study, 13 subjects repeated several words, which contained extreme consonant and vowel tongue positions, during upright and supine condition. Ultrasound imaging provided midsagittal tongue contours, in each condition, for comparison. A neck brace was used to stabilize transducer placement and the palate was used as a physiological reference to register the data sets. Results showed a significant subject effect. In supine position the tongue was more posterior than upright for seven subjects, more anterior for two subjects and varied by phoneme for four subjects. However, there was no significant phoneme effect. The direction of change and the amount of change were not directly related. Most subjects had small upright-supine differences. The largest differences, less than 3 mm on average, were in the posterior tongue.

Studies of associations between disability in multiple sclerosis, skin type, gender and ultraviolet radiation

Recent studies suggest ultraviolet radiation (UVR)/vitamin D is protective against the development of multiple sclerosis (MS). We determined if outcome in MS is associated with the surrogate for host pigmentation, skin type, and parameters of UVR exposure. We used a validated questionnaire to determine skin type and UVR exposure during childhood (0-16 years), and early adult life (17-40 years), in 448 Caucasians with MS. Outcome was assessed using the Kurtzke Expanded Disability Status Score (EDSS) and Multiple Sclerosis Severity Scale (MSSS). We studied the association of skin type and exposure with dichotomized values of EDSS (< and ≥6) and MSSS (continuous variable) using logistic and linear regression analyses, respectively. Sex, onset age and MS duration were significantly associated with outcome in all patients. In 169 females with established disease (≥10 years), sun sensitive skin types 1 and 2 were associated with reduced risk of EDSS ≥6 (odds ratio =0.50; 95% CI = 0.26-0.97), and higher MSSS values (coefficient = -0.86; 95% CI = -1.67 to -0.05). Parameters of UVR exposure were not significantly associated with outcome. These preliminary data show an association between skin type and disability in female MS patients. They are compatible with independent studies suggesting that exposure mediates MS pathogenesis via vitamin D. Further studies are required to properly assess these potentially important findings. Multiple Sclerosis 2007; 13: 369-375. http://msj.sagepub.com

An international study on starting tumour necrosis factor-blocking agents in ankylosing spondylitis

OBJECTIVES

To determine the type and proportion of patients with ankylosing spondylitis who rheumatologists consider to be candidates for treatment with tumour necrosis factor (TNF)-blocking agents, and to what extent this is in agreement with the ASsessment in Ankylosing Spondylitis (ASAS) international working group recommendations on initiation of treatment with anti-TNF agents.

METHODS

Participants were rheumatologists from 10 different countries, who were considered to be experts in treating patients with ankylosing spondylitis and in the use of anti-TNF treatment, but were unaware of the ASAS recommendations (unpublished at the time of study in 2003). The first 10 consecutive patients with ankylosing spondylitis seen by the rheumatologist were evaluated as to whether the patient was a candidate for anti-TNF treatment. Thereafter, a metrologist assessed the patient for disease activity and severity, and collected data on demographics and treatment.

RESULTS

Complete data were available for 1207 of the 1284 patients and were used for analysis. Overall, the rheumatologists indicated that they would initiate TNF-blocking agents in 49.3% of patients, ranging from 37.2% patients in Canada to 78.3% in Australia. These candidates had higher disease activity, higher levels of acute-phase reactants, worse spinal mobility, worse function, more often hip involvement and a higher prevalence of sick leave. Of all patients considered to be candidates, 40% did not fulfil ASAS recommendations with respect to previous use of non-steroidal anti-inflammatory drugs (NSAIDs; at least two NSAIDs) or Bath Ankylosing Spondylitis Disease Activity Index (>or=4). Conversely, 36% of patients who did not fulfil the NSAID or BASDAI recommendations were still considered to be candidates for TNF-blocking treatment.

OBJECTIVE

variables, such as C reactive protein, erythrocyte sedimentation rate or magnetic resonance activity, were considered less important than disease activity in the decision on starting TNF-blocking drugs. The only important objective criterion was rapid radiographic progression.

CONCLUSION

Rheumatologists wanted to initiate TNF-blocking drugs in roughly half of the patients with ankylosing spondylitis. However, there was a wide variation across countries and doctors. Rheumatologists considered both disease activity and severity to be determinants of starting TNF blockers, but their decision was often in disagreement with ASAS recommendations.