Socio-Economic Status in Risk of Acute Adverse Events Following Radiotherapy

PURPOSE/OBJECTIVE(S)

Socio-economic status (SES) are known to influence cancer patient outcomes. The purpose of this study is to evaluate whether SES affected the short-term clinical experience of patients treated with radiotherapy (RT) during the pandemic.

MATERIALS/METHODS

This was a single institution, retrospective cohort quality improvement study. The primary endpoint consisted of adverse events (AEs) defined as an unplanned admission to a drop-in radiation-nursing clinic (RNC) or the institution's emergency department (ED) within 90 days of a radiation course. Adult cancer patients who received external beam RT from April 1, 2019, to March 31, 2022 were included. Patients were classified into two periods: treated prior to the pandemic (pre-COVID), and during the pandemic (COVID era), with a cutoff date of March 31, 2020. SES, age, RT intent (curative, palliative, SBRT), regimen (conventional fractionation and hypofractionation), disease site, and sex were included as co-variables. SES was obtained by matching a patient's postal code with a provincial data tool with four distinct dimensions: 1) residential instability, 2) material deprivation, 3) ethnic concentration, and 4) dependency. For each SES dimension, a score of 1-5 (best-worst) is assigned to individuals. A backward stepwise multivariable logistic regression analysis was performed to analyze the variables and identify the factors that were significantly associated (p<0.05) with increased risk of AEs. Institutional ethics review board exemption was obtained.

RESULTS

Across the 3-year period, 15715 patients (5499 pre-COVID and 10216 COVID era patients) were identified and included in the analyses, and 5756 AEs were observed. The analyses revealed that patient age (p<0.001), disease site (p<0.001), treatment intent (p<0.001) and treatment regimen (p = 0.005) were associated with the risk of developing AEs. AEs risk was correlated with the treatment period (pre-COVID vs. COVID era) (p<0.001) and material deprivation (p = 0.027). Adjusting for the other variables, patients who were least materially deprived were at lower risk (Odds Ratio (OR) = 0.88, 95% CI [0.78-0.98]) of developing AEs than patients who were most materially deprived. Patient sex (p>0.1), residential instability (p = 0.069), ethnic concentration (p>0.5) and dependency (p>0.5) were not associated with AEs risk. Patients with more (SES score 1-4 vs 5) residential instability (p<0.001; OR = 0.82, 95% CI [0.74-0.90]) and less (SES score 1 vs 2-5) material deprivations (p = 0.006; OR = 0.76, 95% CI [0.66-0.88]) were at reduced the risk of ED visits. SES was not associated with RNC visits.

CONCLUSION

In a universal health care system, SES (residential instability and material deprivation) were associated with the increased risk of ED within 90 days of RT. Proactive care and virtual monitoring during the 90-day period after RT in high-risk patients may reduce ED visits. ED visits beyond our tertiary institution are being gathered to address this study limitation.

Analysing the contributions of lower limb muscles to eccentric cycling using musculoskeletal modeling and simulation

Eccentric (ECC) cycling, compared to traditional concentric cycling, has been shown to improve muscle strength and neuromuscular control at a lower metabolic cost. Despite the popularity of this exercise in the sports and rehabilitation contexts, there is a gap in our knowledge of which muscles are behaving eccentrically during ECC cycling. To this end, we used a musculoskeletal model and computer simulations to calculate joint kinematics and muscle lengths during ECC cycling. Movements were recorded using 3D motion capture technology while cycling eccentrically on a custom-built semi-recumbent ergometer. The software Opensim was used to calculate joint kinematics and muscle lengths from recorded movements. We found that among the primary knee extensors, it was predominantly the Vastii muscles that acted eccentrically in the ECC cycling phase, with other lower limb muscles showing mixed eccentric/concentric activation. Additionally, the muscle force-length and force-velocity factors in the ECC phase suggest that changes to the participant's pose and pedaling speed may elicit larger active muscle forces. Our work provides an interesting application of musculoskeletal modeling to ECC cycling, and an alternative way to help understand in-vivo muscle mechanics during this activity.

Evaluating the Short-Term Environmental and Clinical Effects of a Radiation Oncology Department's Response to the COVID-19 Pandemic (STEER COVID-19)

Purpose/Objective(s)

During the COVID-19 pandemic, hypofractionated regimens and virtual care was adopted by our institution to preserve hospital capacity and reduce foot traffic. This study's primary objective was to assess the collective environmental impact of these strategic changes by identifying sources of carbon dioxide equivalents (CO₂e). As sustainable healthcare is only justifiable if the quality of the care is maintained, we also evaluated the rate of radiation-related acute adverse event.

Materials/Methods

All patients treated with external beam radiation therapy from April 1, 2019 to March 31, 2021 at our single institution were identified (n=10,175) along with their radiotherapy visits (176,423 fractions), and visits to the radiation nursing clinic (RNC) or emergency (ER) department. A treatment regimen was considered hypofractionated if the dose per fraction was ≥ 240 cGy. If the dose per fraction was ≥ 600 cGy and the total dose of the treatment regimen was > 2000 cGy, then the treatment regimen was classified as SBRT. Out-patient hospital and virtual visits (n=75,853) during this same period were also analyzed. Environmental impact measures, including linear accelerator power usage, patient travel distances, and personal protection equipment (PPE) consumption were all converted into CO₂e. A waiver of individual patient consent was granted for this study by our institution's Research Ethics Board (REB).

Results

The use of curative hypofractionated regimens increased from 17% to 27% during the pandemic year. Twelve out of 15 cancer sites increased their use of hypofractionated regimens. Carbon footprint was reduced by 39% during the pandemic year (1,332,388 kg CO₂e) as compared to the pre-pandemic year (2,024,823 kg CO₂e). For comparison, the 744 tonnes of CO₂e saved during the pandemic year equates to the CO₂e produced by the annual energy consumption of 182 Canadian households or the CO₂e sequestered by 12,000 seedling trees planted and grown for 10 years. On average 121 kg CO₂e and 100 kg CO₂e were emitted per radiation regimen delivered during the pre-pandemic and pandemic year, respectively. Comparing patients in the pre-pandemic vs. pandemic year, there was a significant reduction in the proportion of hypofractionated patients who needed a visit to either the RNC (39% vs. 25%; p<0.001) or ER (6% vs. 2%; p<0.001) during and within 90 days of radiotherapy.

Conclusion

This study demonstrated the environmental benefits of increased use of hypofractionated regimens and virtual care, while assuring that there was no added acute radiation-related adverse event. Our findings support their continued use as one of many long-term strategies to reduce the environmental footprint of healthcare delivery. Treatment efficacy and side-effects will need to be assessed in subsequent years to further support the sustainability of these strategies.

Comparison of foot strike sound between rearfoot, midfoot and forefoot strike runners

CONTEXT

There are three common foot strike techniques in runners. Whether these techniques generate different sounds at the point of impact with the ground may influence lower limb kinetics. No previous studies have determined whether such relationships exist.

OBJECTIVES

To determine foot-ground impact sound characteristics and to compare the impact sound characteristics across foot strike techniques and the relationships between impact sound characteristics and vertical loading rates.

DESIGN

Cross-sectional study Setting: Gait analysis laboratory Patients or Other Participants: Thirty runners (50% female, age=23.5±4.0 yrs, mass=58.1±8.2kg, height=1.67±0.1m) completed overground running trials with rearfoot strike (RFS), midfoot strike (MFS) and forefoot strike (FFS) techniques in a gait analysis laboratory.

MAIN OUTCOME MEASURE(S)

Impact sound was measured by a shotgun microphone and the peak sound amplitude, median frequency and sound duration were analysed. Separate linear regression, clustering participants repeated measures were used to compare the sound parameters across foot strike techniques. Kinetic data was collected from a force plate and the vertical loading rates were calculated. Pearson's correlation was used to determine relationship between sound characteristic and kinetics.

RESULTS

Landing with a MFS or FFS resulted in greater peak sound amplitude (ps<0.001) and shorter sound duration (ps<0.001) than RFS. MFS exhibited the highest median frequency among the three foot strike patterns, followed by FFS (ps<0.001). We did not find a significant relationship between vertical loading rates and any impact sound parameters (ps>0.115).

CONCLUSIONS

The results suggest that impact sound characteristics may be used to differentiate foot strike patterns in runners. However, this did not relate to lower limb kinetics. Therefore, clinicians should not solely rely on impact sound to infer impact loading.

Training and technique choices predict self-reported running injuries: An international study

OBJECTIVES

The aim of this study was to describe the self-reported injury, training, and running technique choices of regular runners in four international regions.

DESIGN AND SETTING

756 participants began an expert derived self-report online survey in Ireland, USA, Hong Kong and Australia.

PARTICIPANTS

325 participants completed the survey (age = 38 ± 10 years; weight = 68.0 ± 13.1 kg; height = 1.70 ± 0.10 m).

MAIN OUTCOME MEASURES

Descriptive statistics are reported examining injury incidence and location; shoe and orthosis choices; and training and technique practices. A backwards logistic regression was implemented to examine associations between injury and training choices.

RESULTS

68.3% reported having an injury in the last year. 81.45% of these injuries were believed to be running related. A large variation in training and footwear choices were observed for respondents. The regression (P ≤ 0.001) explained 20% of the variance in injury selection (Nagelkerke R²) and was able to identify 73% of cases accurately. Associated injury factors included competitive running, running on more than one surface, younger age, having a lower running age, and a higher proportion of running at an easy intensity.

CONCLUSIONS

The high amount of variability in runner's choices highlights the lack of consistent information being presented to them and may be the reason for the high injury incidence.

Prevalence, characteristics and mortality outcomes of obese, nonobese and lean NAFLD in the United States, 1999-2016

BACKGROUND

Updated prevalence and outcome data for nonobese NAFLD for the multi-ethnic US population is limited.

OBJECTIVES

We aimed to investigate the prevalence, clinical characteristics and mortality of obese and nonobese individuals with NAFLD in the United Sates.

METHODS

A retrospective study was conducted using the 1999-2016 NHANES databases. We determined hazard ratio stratified by obesity status in NAFLD individuals using Cox regression and log-rank test.

RESULTS

Overall NAFLD prevalence was 32.3%: 22.7% were obese and 9.6% were nonobese, with increasing trend over time for obese NAFLD, but not nonobese NAFLD. Amongst those with NAFLD, 29.7% (95% CI: 27.8%-31.7%) were nonobese, of which 13.6% had lean NAFLD. Nonobese NAFLD was more common in older (40.9% if ≥ 65 vs. 24.2% if < 65 years), male (34.0% vs. 24.2%) and foreign-born Asian people (39.8% vs. 11.4%) and uncommon in black (11.5% vs 30-35% in other ethnicities, P < 0.001). Metabolic comorbidities were common in nonobese NAFLD individuals who also had more advanced fibrosis. Nonobese NAFLD individuals had higher 15-year cumulative all-cause mortality (51.7%) than obese NAFLD (27.2%) and non-NAFLD (20.7%) (P < 0.001). However, DM and fibrosis, but neither obese nor nonobese NAFLD compared to non-NAFLD was independently associated with higher mortality.

CONCLUSION

Nonobese NAFLD makes up about one-third of the NAFLD in the United States (even higher in older, male and foreign-born individuals) and carries higher mortality than obese NAFLD. Screening for NAFLD should be considered in high-risk groups even in the absence of obesity.

Ethnic influence on nonalcoholic fatty liver disease prevalence and lack of disease awareness in the United States, 2011-2016

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) is a rising global disease associated with clinical and economic burdens.

OBJECTIVES

We aimed to quantify NAFLD prevalence and awareness to provide stakeholders necessary information to combat NAFLD burden.

METHODS

This study utilizes data from the National Health and Nutrition Examination Survey 2011-2016 and included 4538 adult participants who did not have heavy drinking or viral hepatitis history. The US fatty liver index defined NAFLD and NAFLD fibrosis score defined fibrosis. NAFLD awareness was captured by questionnaire.

RESULTS

Amongst the study population of 4538 persons, NAFLD prevalence was 32.5%, lowest in non-Hispanic Blacks (18.0%) and Asians (18.1%), highest amongst Mexican Americans (48.4%). Within the NAFLD group, advanced fibrosis was highest in non-Hispanic Blacks (28.5%) and lowest amongst non-Hispanic Asians (2.7%). Of the 1473 (97.5%) NAFLD participants who answered NAFLD awareness question, 90% visited a healthcare centre at least once in the past year, but only 5.1% were aware of having NAFLD. On weighted population estimates, 77.33 million persons had NAFLD, 17.63 million had advanced fibrosis, and 73.39 million NAFLD participants were not aware of having NAFLD.

CONCLUSIONS

Of 77.33 million people in the United States have NAFLD with 17.63 million having advanced fibrosis, with lowest prevalence in non-Hispanic Asians and highest in Mexican Americans. A conundrum exists amongst non-Hispanic Blacks who have low NAFLD prevalence but highest prevalence of advanced fibrosis. Awareness of NAFLD was low across all ethnicities. Effort is needed to improve disease awareness whilst addressing NAFLD clinical burden across ethnicities.

The 2014 Survey on Living with Chronic Diseases in Canada on Mood and Anxiety Disorders: a methodological overview

INTRODUCTION

There is a paucity of information about the impact of mood and anxiety disorders on Canadians and the approaches used to manage them. To address this gap, the 2014 Survey on Living with Chronic Diseases in Canada-Mood and Anxiety Disorders Component (SLCDC-MA) was developed. The purpose of this paper is to describe the methodology of the 2014 SLCDC-MA and examine the sociodemographic characteristics of the final sample.

METHODS

The 2014 SLCDC-MA is a cross-sectional follow-up survey that includes Canadians from the 10 provinces aged 18 years and older with mood and/or anxiety disorders diagnosed by a health professional that are expected to last, or have already lasted, six months or more. The survey was developed by the Public Health Agency of Canada (PHAC) through an iterative, consultative process with Statistics Canada and external experts. Statistics Canada performed content testing, designed the sampling frame and strategies and collected and processed the data. PHAC used descriptive analyses to describe the respondents' sociodemographic characteristics, produced nationally representative estimates using survey weights provided by Statistics Canada, and generated variance estimates using bootstrap methodology.

RESULTS

The final 2014 SLCDC-MA sample consists of a total of 3361 respondents (68.9% response rate). Among Canadian adults with mood and/or anxiety disorders, close to twothirds (64%) were female, over half (56%) were married/in a common-law relationship and 60% obtained a post-secondary education. Most were young or middle-aged (85%), Canadian born (88%), of non-Aboriginal status (95%), and resided in an urban setting (82%). Household income was fairly evenly distributed between the adequacy quintiles; however, individuals were more likely to report a household income adequacy within the lowest (23%) versus highest (17%) quintile. Forty-five percent reported having a mood disorder only, 24% an anxiety disorder only and 31% both kinds of disorder.

CONCLUSION

The 2014 SLCDC-MA is the only national household survey to collect information on the experiences of Canadians living with a professionally diagnosed mood and/or anxiety disorder. The information collected offers insights into areas where additional support or interventions may be needed and provides baseline information for future public health research in the area of mental illness.

2-Chloroacetamidine, a novel immunomodulator, suppresses antigen-induced mouse airway inflammation

BACKGROUND

Citrullination is a presently under-recognized posttranslational protein modification catalyzed by PAD enzymes. Immune responses to citrullinated neo-epitopes are identified in a growing number of inflammatory and autoimmune diseases. However, the involvement of hypercitrullination in the pathogenesis of bronchial asthma is still unknown.

METHODS

As main experimental tool, we examined the effect of 2-chloroacetamidine (2CA), a PAD enzyme inhibitor, on OVA-immunized and airway-challenged BALB/c mice; a commonly used model of allergic airway inflammation. We also measured the effect of 2CA on ex vivo lymphocytes and cell lines.

RESULTS

In vivo, 2CA dramatically suppressed lung tissue hypercitrullination, inflammatory cell recruitment, and airway-Th2 cytokine secretion. 2CA also suppressed systemic OVA-specific and total IgE production dramatically, effectively preventing de novo and diminishing established disease without measurably impacting general immunocompetence. In vitro, 2CA markedly inhibited the proliferation of mouse and human T cells with cell cycle block and apoptosis during a limited, postactivation phase.

CONCLUSIONS

2CA acts as narrow-spectrum immunosuppressant that selectively targets lymphocyte populations involved in active inflammatory tissue lesions. If hypercitrullination is generated in patients with asthma, 2CA may represent a novel disease modulator for human asthmatics/allergic diseases.

Comparative effectiveness of the hepatitis C virus protease inhibitors boceprevir and telaprevir in a large U.S. cohort

BACKGROUND

Limited data exist on the effectiveness of boceprevir and telaprevir in routine practice.

AIM

To assess the comparative effectiveness of boceprevir and telaprevir regimens.

METHODS

In this observational, intent-to-treat cohort analysis of hepatitis C genotype 1-infected veterans initiated on peginterferon/ribavirin and boceprevir (n = 661) or telaprevir (n = 198), we determined sustained virological response (SVR), treatment discontinuation rates and adverse haematological events. Inverse probability-of-treatment weighting (IPTW) was used to estimate the effect of one drug over the other, with matched pairs and unweighted logistic regression on the entire cohort for comparison.

RESULTS

Of 835 veterans, SVR occurred in 50% and 52% receiving boceprevir- and telaprevir-based treatment, respectively (P = 0.72). No significant differences occurred among subgroups: cirrhotics (37% vs. 39%, P = 0.94), null responders (23% vs. 18%, P = 0.81), partial responders (39% vs. 58%, P = 0.15) and relapsers (60% vs. 77%, P = 0.11). Early discontinuation rates for boceprevir and telaprevir, respectively, were 31% and 28% by week 24 (P = 0.46) and 54% and 45% by 48 weeks (in those completing at least 28 weeks) (P = 0.14). Choice of telaprevir over boceprevir was significantly associated with SVR in multivariate models (IPTW OR: 1.57, 95% CI: 1.10-2.25, P = 0.01; matched-pairs OR: 1.91, 95% CI: 1.23-3.00, P = 0.004; unweighted OR: 1.50 95% CI: 1.05-2.14, P = 0.02). Rates of haematological adverse events in boceprevir- and telaprevir-treated patients were as follows: anaemia 59% vs. 51%, P = 0.30, thrombocytopenia 41% vs. 48%, P = 0.26, neutropenia 41% vs. 27%, P = 0.04.

CONCLUSIONS

Sustained virological response was more likely with telaprevir-based regimens compared with boceprevir-based regimens in routine medical practice, after accounting for patient differences. Early discontinuation and haematological events, however, were similar.

The water exchange method for colonoscopy-effect of coaching

The growing popularity of water immersion is supported by its long history as an adjunct to air insufflation; after facilitating colonoscope passage, the infused water is conveniently removed during withdrawal. Water exchange, a modification of water immersion to minimize discomfort in scheduled unsedated patients in the U.S. is new. Even though it may be superior in reducing pain and increasing adenoma detection, the paradigm shift to complete exclusion of air during insertion necessitates removal of infused water containing residual feces, a step often perceived as laborious and time-consuming. The nuances are the efficient steps to remove infused water predominantly during insertion to maintain minimal distension and deliver salvage cleansing. Mastery of the novel maneuvers with practice returns insertion time towards baseline. In this observational study the impact of direct verbal coaching on the primary outcome of intention-to-treat cecal intubation was assessed. The results showed that 14 of 19 (74%) experienced colonoscopists achieved 100% intention-to-treat cecal intubation. Initiation of the examination with water exchange did not preclude completion when conversion to the more familiar air insufflation method was deemed necessary to achieve cecal intubation (total 98%). The overall intention-to-treat cecal intubation rate was 88%, 90% in male and 87% in female. Only 2.7% of bowel preparation was rated as poor during withdrawal. The mean volume of water infused and cecal intubation time was 1558 ml and 18 min, respectively. Direct coaching appears to facilitate understanding of the nuances of the water exchange method. Studies of individual learning curves are necessary.

Implications of rapid virological response in hepatitis C therapy in the US veteran population

BACKGROUND

Early predictors of response to hepatitis C virus (HCV) therapy, such as rapid virological response, are valuable for the identification of patients with a higher likelihood of treatment success.

AIM

To identify predictors of rapid virological response in a real world setting.

METHODS

Using the VA Clinical Case Registry, we identified patients with HCV mono-infection, without liver transplantation, who initiated peginterferon (PEG-IFN) and ribavirin (RBV) in 2007 or 2008 and had HCV RNA testing for RVR. Significant baseline characteristics from genotype specific univariate analyses were used in backwards stepwise models to identify significant independent predictors of RVR.

RESULTS

The final cohort consisted of 2424 patients with genotype 1 (G1), 666 patients with genotype 2 (G2), and 419 patients with genotype 3 (G3). Rapid virological response rates were 15% for G1, 71% for G2 and 57% for G3. Sustained virological response rates were significantly higher in patients with rapid virological response than without, increasing from 18% to 52% in G1, 39% to 71% in G2, and 40% to 60% in G3 (P < 0.0001). A baseline HCV RNA < 500,000 IU/mL positively predicted RVR across all genotypes studied. In addition, for G1, Black race, Hispanic ethnicity, aspartate aminotransferase/alanine aminotransferase (AST/ALT) ≥ 0.6, ferritin ≥ 350 ng/mL, LDL< 100 mg/dL and diabetes; for G2, BMI ≥ 30 kg/m(2), platelets < 150 K/μL, LDL< 100 mg/dL and the use of PEG-IFN alfa-2b; and for G3, AST/ALT ≥ 1.0, all negatively predicted rapid virological response.

CONCLUSION

We found several novel independent predictors of rapid virological response, including BMI, AST/ALT ratio, ferritin, platelets, LDL, diabetes and type of PEG-IFN prescribed, which may be useful in guiding treatment decisions in routine medical practice.

Cholecalciferol plus calcium suppresses abnormal PBMC reactivity in patients with multiple sclerosis

CONTEXT

The active metabolite of vitamin D, 1,25-dihydroxyvitamin D [1,25(OH)(2)D], is a potent modulator of immune cells in vitro.

OBJECTIVE

Our objective was to determine whether the sun-dependent nutrient, cholecalciferol, can alter disease-associated cellular immune abnormalities in patients with multiple sclerosis (MS).

DESIGN

This was an open-label, 12-month, randomized controlled trial.

SETTING

Patients with MS were recruited from the MS Clinic at St. Michael's Hospital, Toronto.

PATIENTS

Forty-nine patients were matched (for age, sex, disease duration, disease-modifying drug, and disability) and enrolled (treated n = 25; control n = 24). Four patients were lost to follow-up (n = 2 from each group).

INTERVENTION

Treated patients received increasing doses of cholecalciferol (4,000-40,000 IU/d) plus calcium (1200 mg/d), followed by equilibration to a moderate, physiological intake (10,000 IU/d). Control patients did not receive supplements.

MAIN OUTCOME MEASURES

At enrollment and at 12 months, peripheral blood mononuclear cell (PBMC) proliferative responses to disease-associated, MS-relevant, and control antigens were measured, along with selected serum biochemical markers.

RESULTS

At 12 months, mean serum 25-hydroxyvitamin D [25(OH)D] concentrations were 83 ± 35 nmol/liter and 179 ± 76 nmol/liter in control and treated participants, respectively (paired t, P < 0.001). Serum 1,25(OH)(2)D did not differ between baseline and 1 yr. In treated patients, 12-month PBMC proliferative responses to neuron antigens myelin basic protein and exon-2 were suppressed (P = 0.002). In controls, there were no significant changes in disease-associated PBMC responsiveness. There were no significant differences between groups in levels of selected biomarkers.

INTERPRETATION

MS-associated, abnormal T cell reactivities were suppressed in vivo by cholecalciferol at serum 25(OH)D concentrations higher than 100 nmol/liter.

Effects of Confinement on Plastic Deformation in Passivated Al Films

Wafer curvature measurements of a trilayer (SiO2 / AlSiCu / Si) structure are compared to that predicted by a weighted sum of individual measurements of SiO2 and AISiCu films on Si, and significant differences are found to exist for temperatures above 200°C. A straightforward analysis of the stresses in each layer has been modeled using an extension of a model by Feng et al. which assumes uniform plastic deformation throughout the Al. The modeling results suggest a straightforeward method for determining stresses in deformable thin films that are confined by elastic overlayers. A comparison of the stress-temperature behavior for unpassivated and passivated AISiCu films reveals that the confined films exhibit less plastic deformation and both higher tension and compression during thermal cycling.

Study of the dispersion and electrical properties of carbon nanotubes treated by surfactants in dimethylacetamide

In this study, the effects of sodium dodecyl benzene sulfonate, polyvinylpyrrolidone, sodium dodecyl benzene sulfonate/polyvinylpyrrolidone, and Triton X-100 on the dispersion of 0.1 wt% carbon nanotubes in dimethylacetamide are reported. Sedimentation results show that except for sodium dodecyl benzene sulfonate, all the surfactant-assisted carbon nanotube solutions have visually-stable dispersions for at least two months, and even the samples without a surfactant gave no obvious deposition. UV-Vis spectra of the dispersions with and without acid-treatment proved that the carboxyl group attached to the carbon nanotubes positively improves the dispersion effect. The states of aggregation of carbon nanotubes treated by different surfactants are distinctive, and the electrical properties of carbon nanotubes are strongly related to these states of aggregation. The best dispersing and stabilizing effect was found in the sodium dodecyl benzene sulfonate/polyvinylpyrrolidone sample, which also gave the lowest resistance (2.15 x 10(4) omega at 20 V) among all the surfactant-treated stable suspensions.

A phase I/II dose-escalation trial of vitamin D3 and calcium in multiple sclerosis

OBJECTIVE

Low vitamin D status has been associated with multiple sclerosis (MS) prevalence and risk, but the therapeutic potential of vitamin D in established MS has not been explored. Our aim was to assess the tolerability of high-dose oral vitamin D and its impact on biochemical, immunologic, and clinical outcomes in patients with MS prospectively.

METHODS

An open-label randomized prospective controlled 52-week trial matched patients with MS for demographic and disease characteristics, with randomization to treatment or control groups. Treatment patients received escalating vitamin D doses up to 40,000 IU/day over 28 weeks to raise serum 25-hydroxyvitamin D [25(OH)D] rapidly and assess tolerability, followed by 10,000 IU/day (12 weeks), and further downtitrated to 0 IU/day. Calcium (1,200 mg/day) was given throughout the trial. Primary endpoints were mean change in serum calcium at each vitamin D dose and a comparison of serum calcium between groups. Secondary endpoints included 25(OH)D and other biochemical measures, immunologic biomarkers, relapse events, and Expanded Disability Status Scale (EDSS) score.

RESULTS

Forty-nine patients (25 treatment, 24 control) were enrolled [mean age 40.5 years, EDSS 1.34, and 25(OH)D 78 nmol/L]. All calcium-related measures within and between groups were normal. Despite a mean peak 25(OH)D of 413 nmol/L, no significant adverse events occurred. Although there may have been confounding variables in clinical outcomes, treatment group patients appeared to have fewer relapse events and a persistent reduction in T-cell proliferation compared to controls.

CONCLUSIONS

High-dose vitamin D (approximately 10,000 IU/day) in multiple sclerosis is safe, with evidence of immunomodulatory effects.

CLASSIFICATION OF EVIDENCE

This trial provides Class II evidence that high-dose vitamin D use for 52 weeks in patients with multiple sclerosis does not significantly increase serum calcium levels when compared to patients not on high-dose supplementation. The trial, however, lacked statistical precision and the design requirements to adequately assess changes in clinical disease measures (relapses and Expanded Disability Status Scale scores), providing only Class level IV evidence for these outcomes.

VITATOPS, the VITAmins TO prevent stroke trial: rationale and design of a randomised trial of B-vitamin therapy in patients with recent transient ischaemic attack or stroke (NCT00097669) (ISRCTN74743444)

BACKGROUND

Epidemiological studies suggest that raised plasma concentrations of total homocysteine (tHcy) may be a common, causal and treatable risk factor for atherothromboembolic ischaemic stroke, dementia and depression. Although tHcy can be lowered effectively with small doses of folic acid, vitamin B(12) and vitamin B(6), it is not known whether lowering tHcy, by means of B vitamin therapy, can prevent stroke and other major atherothromboembolic vascular events.

AIM

To determine whether the addition of B-vitamin supplements (folic acid 2 mg, B(6) 25 mg, B(12) 500 microg) to best medical and surgical management will reduce the combined incidence of stroke, myocardial infarction (MI) and vascular death in patients with recent stroke or transient ischaemic attack (TIA) of the brain or eye.

DESIGN

A prospective, international, multicentre, randomised, double blind, placebo-controlled clinical trial.

SETTING

One hundred and four medical centres in 20 countries on five continents.

SUBJECTS

Eight thousand (6600 recruited as of 5 January, 2006) patients with recent (<7 months) stroke (ischaemic or haemorrhagic) or TIA (brain or eye).

RANDOMISATION

Randomisation and data collection are performed by means of a central telephone service or secure internet site.

INTERVENTION

One tablet daily of either placebo or B vitamins (folic acid 2 mg, B(6) 25 mg, B(12) 500 mug).

PRIMARY OUTCOME

The composite of stroke, MI or death from any vascular cause, whichever occurs first. Outcome and serious adverse events are adjudicated blinded to treatment allocation.

SECONDARY OUTCOMES

TIA, unstable angina, revascularisation procedures, dementia, depression. STATISTICAL POWER: With 8000 patients followed up for a median of 2 years and an annual incidence of the primary outcome of 8% among patients assigned placebo, the study will have at least 80% power to detect a relative reduction of 15% in the incidence of the primary outcome among patients assigned B vitamins (to 6.8%/year), applying a two-tailed level of significance of 5%.

CONCLUSION

VITATOPS aims to recruit and follow-up 8000 patients between 1998 and 2008, and provide a reliable estimate of the safety and effectiveness of folic acid, vitamin B(12), and vitamin B(6) supplementation in reducing recurrent serious vascular events among a wide range of patients with TIA and stroke throughout the world.

Persistence with hepatitis C therapy in the Department of Veterans Affairs

BACKGROUND

Persistence with Hepatitis C therapy has been identified as a key variable for predicting treatment success. The primary purpose of this study was to assess the persistence with therapy for patients undergoing hepatitis C treatment in the VA healthcare system with two forms of combination therapies: peginterferon alfa-2a with Ribavirin (peg-IFN alpha-2a/Rib) and peginterferon alpha-2b with Ribavirin (peg-IFN alpha-2b/Rib).

METHODS

A retrospective cohort study design was used to analyse persistence in VA patients undergoing hepatitis C therapy during FY 2003-2004 using a large national VA data set. Stringent inclusion and exclusion criteria along with various defining variables were used to identify the inception cohort. Persistence rates were calculated for each of the two treatment groups at 3, 6, 9 and 11 months using the Kaplan-Meier method. Likelihood ratio test of equality between the two treatment groups was performed to detect any differences in persistence rates.

RESULTS

A total of 5816 hepatitis C patients formed the inception cohort. Persistence rates for the overall duration showed significantly higher rates for patients on peg-IFN alpha-2a/Rib than peg-IFN alpha-2b/Rib. Cox regression analysis also showed favourable hazard ratio of persistence (0.88) for peg-IFN alpha-2a/Rib over peg-IFN alpha-2b/Rib.

CONCLUSION

Peg alfa-2A/Rib showed slightly higher persistence rates for the overall duration of treatment as compared to Peg alfa-2B/Rib. However the differences, even though statistically significant, are small and not likely to translate into any substantial clinical advantage. Further research involving other approaches is required to confirm these findings.

Intravenous Parecoxib Rapidly Leads to COX-2 Inhibitory Concentration of Valdecoxib in the Central Nervous System

Evidence in animal studies supports widespread induction of cyclooxygenase-2 (COX-2) in the central nervous system (CNS) following tissue injury, probably mediated by cytokines, transducing the signal across the blood-brain barrier. CNS COX-2 blockade is a possible therapeutic target for drugs that are able to reach adequate CNS levels and abolish the prostaglandin E2-induced central sensitization. This human pharmacokinetic study investigated valdecoxib cerebrospinal fluid (CSF) and plasma concentrations over time in 37 patients following 40 mg of single-dose intravenous parecoxib. High-performance liquid chromatography/tandem mass spectrometry analysis was performed. Valdecoxib was first detectable in the CSF at 15 min postdosing, increased rapidly until 50 min, and thereafter remained between 6 and 14 ng/ml. This is the first human study demonstrating CNS COX-2 inhibitor penetration as early as 15 min. CSF valdecoxib concentration rapidly reached in vitro IC50 (inhibitory concentration 50) (1.57 ng/ml) by 17 min and remained consistently higher thereafter.

Effect of zoledronate on bone quality in the treatment of aseptic loosening of hip arthroplasty in the dog

Periprosthetic bone loss, which is a direct cause of aseptic loosening in total hip arthroplasty (THA), can be suppressed by bisphosphonates. It is unknown how the quality of this bone is affected in the presence of both wear debris (from implant) and bisphosphonates. The objective of this study was to evaluate the effect of zoledronate (ZLN) on bone quality in the presence of wear debris [polyethylene (PE) particles] in a canine model of uncemented THA. Thirty dogs underwent THA, and aseptic loosening was induced via implantation of PE particles packed into the femoral component. For 26 weeks until sacrifice, two groups (each n = 10) received weekly injections of ZLN (low dose 2 mug/kg, high dose 10 mug/kg) and the third group (control) received saline. Histological and radiographic examinations were performed to evaluate the degree of implant reaction. Histomorphometry (static/dynamic) was performed to evaluate bone turnover. Back-scattered electron imaging was used to quantify the newly formed bone and to evaluate the mineralization distribution. Density fractionation and X-ray diffraction were used to evaluate mineral properties, while four-point bending was used to determine mechanical properties. A dose-dependent presence of newly formed subperiosteal bone was found, which appeared to be less mineralized than the adjacent cortical bone. The high-dose ZLN group showed decreased cortical porosity and turnover and increased mineralization profile, failure strength, and modulus. We conclude that ZLN affects some of the material properties of cortical bone and allows the newly formed subperiosteal bone to remain and therefore affect the overall quality of the bone.