Genotoxicity of carbon nanofibers: are they potentially more or less dangerous than carbon nanotubes or asbestos?

The production of carbon nanofibers and nanotubes (CNF/CNT) and their composite products is increasing globally. CNF are generating great interest in industrial sectors such as energy production and electronics, where alternative materials may have limited performance or are produced at a much higher cost. However, despite the increasing industrial use of carbon nanofibers, information on their potential adverse health effects is limited. In the current study, we examine the cytotoxic and genotoxic potential of carbon-based nanofibers (Pyrograf®-III) and compare this material with the effects of asbestos fibers (crocidolite) or single-walled carbon nanotubes (SWCNT). The genotoxic effects in the lung fibroblast (V79) cell line were examined using two complementary assays: the comet assay and micronucleus (MN) test. In addition, we utilized fluorescence in situ hybridization to detect the chromatin pan-centromeric signals within the MN indicating their origin by aneugenic (chromosomal malsegregation) or clastogenic (chromosome breakage) mechanisms. Cytotoxicity tests revealed a concentration- and time-dependent loss of V79 cell viability after exposure to all tested materials in the following sequence: asbestos>CNF>SWCNT. Additionally, cellular uptake and generation of oxygen radicals was seen in the murine RAW264.7 macrophages following exposure to CNF or asbestos but not after administration of SWCNT. DNA damage and MN induction were found after exposure to all tested materials with the strongest effect seen for CNF. Finally, we demonstrated that CNF induced predominantly centromere-positive MN in primary human small airway epithelial cells (SAEC) indicating aneugenic events. Further investigations are warranted to elucidate the possible mechanisms involved in CNF-induced genotoxicity.

Antiquity of the biological sulphur cycle: evidence from sulphur and carbon isotopes in 2700 million-year-old rocks of the Belingwe Belt, Zimbabwe

Sulphur and carbon isotopic analyses on small samples of kerogens and sulphide minerals from biogenic and non-biogenic sediments of the 2.7 x 10(9) years(Ga)-old Belingwe Greenstone Belt (Zimbabwe) imply that a complex biological sulphur cycle was in operation. Sulphur isotopic compositions display a wider range of biological fractionation than hitherto reported from the Archaean. Carbon isotopic values in kerogen record fractionations characteristic of rubisco activity methanogenesis and methylotrophy and possibly anoxygenic photosynthesis. Carbon and sulphur isotopic fractionations have been interpreted in terms of metabolic processes in 2.7 Ga prokaryote mat communities, and indicate the operation of a diverse array of metabolic processes. The results are consistent with models of early molecular evolution derived from ribosomal RNA.

Effects of anti-viral therapy and HCV clearance on cerebral metabolism and cognition

BACKGROUND & AIMS

Chronic hepatitis C virus (HCV) infection is associated with altered cerebral metabolism and cognitive dysfunction. We aimed to evaluate the effect of pegylated interferon/ribavirin (PIFN/R) and HCV clearance on cerebral metabolism, and neuropsychological performance.

METHODS

Fifteen non-cirrhotic HCV positive subjects underwent (1)H MR spectroscopy (MRS) before, during, and after treatment with PIFN/R. The metabolites of interest namely, N-acetylaspartate (NAA), choline (Cho), myo-inositol (MI), and the control metabolite creatine (Cr), were acquired from 3 different brain regions; left basal ganglia, left frontal cortex, and left dorso-lateral pre-frontal cortex. Coinciding with this, subjects also underwent a battery of neuropsychological tests to evaluate the domains of verbal learning, memory, attention, language, executive functioning, and motor skills. Seven HCV positive controls (not receiving anti-viral therapy) underwent MRS and neuropsychological testing at two time points, 12 weeks apart, to examine for variation in cerebral metabolites over time and the practice effect of repeat neuropsychological testing.

RESULTS

Significant reductions in basal ganglia Cho/Cr (p=0.03) and basal ganglia MI/Cr (p=0.03) were observed in sustained virological responders (SVRs, n=8), but not non-responders/relapsers (NR/R, n=6), indicative of reduced cerebral infection and/or immune activation in those who cleared virus. SVRs demonstrated significant improvements in verbal learning, memory, and visuo-spatial memory. A small but significant improvement in neurocognitive function secondary to the practice effect was seen in both HCV controls and HCV subjects during treatment.

CONCLUSIONS

HCV eradication has a beneficial effect on cerebral metabolism and selective aspects of neurocognitive function and is an important factor when contemplating anti-viral therapy in HCV, especially in those with mild disease.

Genetic counseling for women with an intermediate family history of breast cancer

Women with a family history of breast cancer often over-estimate their personal risk for cancer and may view themselves as candidates for genetic testing even when the likelihood of an informative test result is low. We report here on genetic counseling of women with an intermediate family history of breast cancer, defined as women who have one or more biological relatives with breast cancer but whose pedigree suggests a low likelihood of autosomal dominant transmission. A genetic counseling protocol based on traditional genetic counseling strategies was developed with additional components added to address the needs of women with moderately increased breast cancer risk. These additional components included information about non-genetic risk factors, comparisons of high and moderate risk pedigrees, and evaluation of personal risk based on both genetic and nongenetic risk factors. Most participants liked the genetic counseling and found it useful. At baseline, participants over-estimated both their personal risk of breast cancer and that of the average woman. After counseling, estimates of personal and average risk of breast cancer were lower, although both remained higher than actual risk. Most participants reported that they felt less worried about breast cancer after receiving their personal-risk estimate. At baseline, most women judged themselves to be candidates for genetic testing and expressed interest in testing. The number who considered themselves candidates for testing was reduced after counseling (60% versus 82%) but still constituted a majority. Similarly, interest in testing was partially reduced by counseling (60% versus 91%). We conclude that genetic counseling can help women with an intermediate family history of breast cancer to develop more accurate views of their risk, reduce their breast cancer worry, and aid some of them in developing a more realistic view of genetic testing.

Emission of methane from plants

It has been proposed that plants are capable of producing methane by a novel and unidentified biochemical pathway. Emission of methane with an apparently biological origin was recorded from both whole plants and detached leaves. This was the first report of methanogenesis in an aerobic setting, and was estimated to account for 10-45 per cent of the global methane source. Here, we show that plants do not contain a known biochemical pathway to synthesize methane. However, under high UV stress conditions, there may be spontaneous breakdown of plant material, which releases methane. In addition, plants take up and transpire water containing dissolved methane, leading to the observation that methane is released. Together with a new analysis of global methane levels from satellite retrievals, we conclude that plants are not a major source of the global methane production.

Randomized, double-blind comparison of growth in infants receiving goat milk formula versus cow milk infant formula

OBJECTIVE

To compare growth of infants fed goat milk infant formula (GMF) or cow milk infant formula (CMF) and to compare tolerability and safety of the two formulas.

METHODS

The study was conducted in Auckland, New Zealand. This was a double-blind randomized controlled trial. Newborn term infants were randomized within 72 h of birth to GMF or CMF. Milk formula powder in single serve sachets were reconstituted and fed to infants from trial commencement until age 168 days. No other formula given from randomization until age 168 days. Infant weight, length and head circumference were measured at birth and age 14, 28, 56, 84, 112, 140 and 168 days. Bowel motion frequency and consistency, sleeping and crying patterns and adverse events were also measured.

RESULTS

Seventy-two infants were randomized, 36 each to GMF or CMF, with 62 infants completing the intervention. At enrollment the average weight of infants in the GMF group (mean +/- SD) was 3.33 +/- 0.43 kg and in the CMF group 3.43 +/- 0.47 kg; and at study completion 8.07 +/- 0.90 kg (GMF) and 7.87 +/- 0.99 kg (CMF). The difference in average weight gain over the study period for the GMF group versus the CMF group was not significant (+309 g; 95% CI = -49 to +668, P = 0.09). Median daily bowel motion frequency was greater in the GMF group than the CMF group (2.4 vs 1.7, P = 0.01). There were no group differences in bowel motion consistency, duration of crying, ease of settling, or frequency of adverse events.

CONCLUSION

Growth of infants fed GMF is not different to that of infants-fed CMF.

Investigating health-related quality of life, mood and neuropsychological test performance in a homogeneous cohort of Irish female hepatitis C patients

Neurocognitive dysfunction has been reported in individuals with chronic hepatitis C (CHC) infection, but HCV populations investigated have often included participants with numerous potential confounding comorbidities. This pilot study sought to investigate functional capacity and neurocognitive function in a homogeneous state-infected HCV population with histologically defined mild liver disease, free from the comorbid factors typically associated with HCV populations. A further aim was to examine cognitive function in a treatment naive population with a similar history of iatrogenic HCV exposure and spontaneous viral clearance. A convenience sample of 29 women, all of whom were carefully screened to exclude relevant comorbidities, was recruited to the study. Twenty women with a history of iatrogenic HCV exposure were recruited from prospective specialist tertiary care liver clinics. A comparison group of healthy controls (n = 9) was also assessed. Study participants underwent mood, health-related quality of life and neuropsychological assessment. CHC patients reported significantly higher levels of cognitive fatigue than healthy controls (F = 3.4, P = 0.04). On cognitive testing, CHC patients showed impairments compared with healthy controls on estimates of general memory [F(2,25) = 4.1, P = 0.03, partial eta squared = 0.25], delayed auditory recognition [F(2,25) = 4.2, P = 0.03, partial eta squared= 0.22] and sustained attention [F(2,25) = 3.6, P = 0.04, partial eta squared = 0.22]. Increased cognitive fatigue only correlated with delayed auditory memory recall ability (r = 0.724, P = 0.006). In conclusion, these findings appear to support the presence of neurocognitive abnormalities in an iatrogenically infected, homogeneous female HCV population who were carefully screened to eliminate other factors affecting neurocognitive test performance and may indicate underlying neurophysiological causative mechanisms.

Intracellular uptake of EGCG-loaded deformable controlled release liposomes for skin cancer

Caucasian population groups have a higher propensity to develop skin cancer, and associated clinical interventions often present substantial financial burden on healthcare services. Conventional treatments are often not suitable for all patient groups as a result of poor efficacy and toxicity profiles. The primary objective of this study was to develop a deformable liposomal formulation, the properties of which being dictated by the surfactant Tween 20, for the dermal cellular delivery of epigallocatechin gallatein (EGCG), a compound possessing antineoplastic properties. The results demonstrated a significant (p ≤ 0.05) decrease in liposome deformability index (74 ± 8 to 37 ± 7) as Tween 20 loading increased from 0 to 10% w/w, indicating an increase in elasticity. EGCG release over 24-h demonstrated Tween 20 incorporation directly increased release from 13.7% ± 1.1% to 94.4% ± 4.9% (for 0 and 10% w/w Tween 20 respectively). Finally, we demonstrated DilC-loaded deformable liposomes were localized intracellularly within human dermal fibroblast and keratinocyte cells within 2 h. Thus, it was evident that deformable liposomes may aid drug penetration into dermal cells and would be useful in developing a controlled-release formulation.

Improved postoperative analgesia with preoperative piroxicam

PURPOSE

Piroxicam like other Non-Steroidal Anti-Inflammatory drugs can be used to provide postoperative analgesia. With a half-life of 50 hr given preoperatively its' analgesic effect should continue postoperatively. This study compared the effects of 20 mg piroxicam given at different times in the perioperative period on postoperative analgesic requirement.

METHOD

Following ethical committee approval and written informed consent, 60 ASA I and II patients presenting for inpatient gynaecological laparoscopic surgery were given either 20 mg piroxicam or a placebo po two hours preoperatively, immediately before induction of anaesthesia or one hour postoperatively in a randomised double bind manner.

RESULTS

Postoperative Visual Analogue Pain Scores were lower on admission to the recovery ward in patients given piroxicam preoperatively (Group 1), than in the other two treatment groups (groups 2 and 3). Pain scores were 2.72 vs 4.25 vs 6.67 respectively (P < 0.001). Pain scores did not differ at any other times. Time to first analgesic request was greater in the group 1 than in the other two treatment groups; 141 (61) min vs 115 (147) in Group 2 and 30 (36) min in Group 3. Nine patients in Group 1 requested further analgesia compared with 15 in Group 2 and 16 in Group 3. There were no piroxicam-induced side-effects.

CONCLUSION

Piroxicam given two hours preoperatively reduced pain scores, time to first analgesia and postoperative analgesic requirements compared with administration prior to induction or one hour postoperatively.

Sulfur isotope analysis of sulfide and sulfate minerals by continuous flow-isotope ratio mass spectrometry

A continuous flow method (CF-IRMS) for the rapid determination of the sulfur isotope composition of sulfide and sulfate minerals has significant advantages over the classic extraction method in terms of the reduced sample quantity and a rapid analytical cycle of less than 8 min/ analysis. For optimum performance, the technique is sensitive to a number of operating parameters, including sample weight and the O2 saturation of the Cu-reduction reactor. Raw data are corrected using a calibration based on five international and internal standards ranging from -17.3 to +20.3 per thousand, which requires monitoring in order to correct the effect of changing delta18O of the sample gas on the measured mass 66 values. Measured sulfur contents are within 1-1.5% of expected values and the reproducibility of delta34S values is +/-0.1 per thousand (1sigma). The technique has been used successfully for more than 1000 analyses of geological samples with a wide range of delta34S from -20 to +20 per thousand.

A note on some reinforcing properties of university lectures

Contingency management systems in university courses have sometimes assigned the role of reinforcing stimulus to lectures and demonstrations. Attending a lecture was made contingent upon having previously finished certain course assignments. The present paper investigated some variables that control student attendance at lectures. Attendance remained high throughout each course at those class meetings where quizzes contributing to course grades were given or where impending quizzes were discussed. Attendance at lectures over the reading assignments or over material unrelated to course quizzes rapidly declined. When students were given course credit for attending these lectures, or when the lectures included information for future quizzes, attendance increased. When attending these lectures was made contingent upon having completed certain assignments the prior week, no increase in assignment completion was noted and the attendance at the lectures decreased even further. All lectures were given during one class meeting each week. Attendance at the other class meetings during the week remained stable.

Comparison of targeted and whole genome analysis of postnatal specimens using a commercially available array based comparative genomic hybridisation (aCGH) microarray platform

PURPOSE

The University of Utah Comparative Genomic Hybridization Microarray Laboratory was one of the first US laboratories to offer comparative genomic hybridisation (CGH) microarray testing using a commercial platform in a clinical setting. Results for 1076 patients (1598 chips) are presented.

METHODS

The Spectral Genomics/PerkinElmer Constitutional Chip (targeted array), SpectralChip 2600 (whole genome array) and a "Combo" chip (both arrays run simultaneously) were the tests offered. Abnormal results were confirmed by an alternative method, most often fluorescence in situ hybridisation.

RESULTS

In 669 cases with known normal cytogenetics, an abnormal detection rate of 10.8% was observed, (5.3%, 12.2% and 14.1% for the Constitutional Chip, SpectralChip 2600 and Combo assay, respectively). Known copy number variants and single clone abnormalities are not included in these rates. Single clone abnormalities are reported separately. For 1076 total cases, we report an average abnormal rate of 16.9% (8.7%, 23.7% and 18.6% for the three assays). This rate includes characterisation of some abnormalities previously identified by cytogenetics.

CONCLUSIONS

CGH microarray provides a likely aetiology for the clinical phenotype in many cytogenetically normal cases, and a whole genome array generally identifies copy number changes more effectively than a targeted chip alone.

True Ileal Amino Acid Digestibility of Goat and Cow Milk Infant Formulas

Goat milk is used as an alternative to cow milk for the production of infant formulas. However, little is known about the protein quality and, specifically, about the digestible AA pattern of goat milk formulas compared with their cow milk counterparts. In this study, the true ileal AA digestibility of a goat milk infant formula was compared with a premium cow milk infant formula. The 3-wk-old piglet was used as a model for the 3-mo-old infant. Both milk formulas were prepared as described by the manufacturer, with titanium dioxide added as an indigestible marker. The formulas were fed to the piglets over a 2-wk trial period. Digesta from the terminal ileum were collected post euthanasia and analyzed for AA content, along with samples of the formulas. True AA digestibility was determined after correcting for endogenous AA loss at the terminal ileum of pigs fed an enzyme-hydrolyzed casein-based diet, followed by ultrafiltration (5,000 Da) of the digesta. Total urine and feces collection was also undertaken to determine the nitrogen retention from the diets. The true ileal AA digestibility was similar between the goat and cow milk infant formulas for all AA except Gly and Trp. There was no significant difference in the nitrogen retention of piglets fed the two different formulas. The goat milk infant formula and the premium cow milk infant formula were similar in terms of protein quality.

Cooperation of p53 loss of function and v-Ha-ras in transformation of mouse keratinocyte cell lines

We previously demonstrated that after transduction with the v-Ha-ras oncogene and grafting onto nude mouse hosts, primary epidermal keratinocytes with a null mutation in the p53 gene form tumors with increased growth rates and predisposition to malignant conversion relative to p53 wild-type keratinocytes (Weinberg WC, et al., Cancer Res 54:5584-5592, 1994). To further explore the cooperation between p53 loss of function and activation of the ras oncogene, cell lines were established from the normal epidermises of newborn and adult p53-null mice, and parallel subclones were reconstituted with the p53val135 temperature-sensitive mutant. Reconstituted lines C, G, N, and V demonstrated functional p53 transcriptional activator activity at the wild-type-permissive temperature of 32 degrees C, compared with the hygromycin-selected control line X and parental p53-null lines NHK4 and AK1b. Hygromycin-selected subclones, but not the parental lines, made normal skin in vivo; all cell lines made carcinomas after introduction of v-Ha-ras, independent of p53 status. These cell lines were compared in vitro at 32 degrees C to maximize the amount of p53val135 in the wild-type conformation. Expression of v-Ha-ras did not consistently alter p53-mediated transcriptional activity, suggesting tat ras acts downstream or independently of p53. No correlation was observed between p53-mediated transcriptional activity and in vitro growth rates, colony formation after exposure to ultraviolet light, or suppression by normal neighboring keratinocytes. However, keratinocyte cell lines devoid of p53 and expressing v-Ha-ras formed colonies in soft agar; this was blocked at 32 degrees C in all cell lines reconstituted with p53val135. These keratinocyte lines provide a model for exploring the role of p53 and the interaction of p53 and ras in keratinocyte transformation.

Exercise combined with Acceptance and Commitment Therapy (ExACT) compared to a supervised exercise programme for adults with chronic pain: study protocol for a randomised controlled trial

Background

Acceptance and Commitment Therapy (ACT) is a form of cognitive behavioural therapy, which may be beneficial for people with chronic pain. The approach aims to enhance daily functioning through increased psychological flexibility. Whilst the therapeutic model behind ACT appears well suited to chronic pain, there is a need for further research to test its effectiveness in clinical practice, particularly with regards to combining ACT with physical exercise.

Methods/design

This prospective, two-armed, parallel-group, single-centre randomised controlled trial (RCT) will assess the effectiveness of a combined Exercise and ACT programme, in comparison to supervised exercise for chronic pain. One hundred and sixty patients, aged 18 years and over, who have been diagnosed with a chronic pain condition by a physician will be recruited to the trial. Participants will be individually randomised to one of two 8-week, group interventions. The combined group will take part in weekly psychology sessions based on the ACT approach, in addition to supervised exercise classes led by a physiotherapist. The control group will attend weekly supervised exercise classes but will not take part in an ACT programme. The primary outcome will be pain interference at 12-week follow-up, measured using the Brief Pain Inventory-Interference Scale. Secondary outcomes will include self-reported pain severity, self-perception of change, patient satisfaction, quality of life, depression, anxiety and healthcare utilisation. Treatment process measures will include self-efficacy, pain catastrophising, fear avoidance, pain acceptance and committed action. Physical activity will be measured using Fitbit Zip^TM activity trackers. Both groups will be followed up post intervention and again after 12 weeks. Estimates of treatment effects at follow-up will be based on an intention-to-treat framework, implemented using a linear mixed-effects model. Individual and focus group qualitative interviews will be undertaken with a purposeful sample of participants to explore patient experiences of both treatments.

Discussion

To our knowledge, this will be the first RCT to examine whether combining exercise with ACT produces greater benefit for patients with chronic pain, compared to a standalone supervised exercise programme.

Trial registration

www.ClinicalTrials.gov, ID: NCT03050528. Registered on 13 February 2017.

Electronic supplementary material

The online version of this article (10.1186/s13063-018-2543-5) contains supplementary material, which is available to authorized users.

Mineral Retention in Three-Week-Old Piglets Fed Goat and Cow Milk Infant Formulas

Goat milk and cow milk are commonly used in infant formula preparations and, as such, understanding the nutritional characteristics of infant formulas made from these milks is important. In this study, a goat milk infant formula was compared with an adapted (whey-enhanced) cow milk infant formula with respect to mineral absorption and deposition using the 3-wk-old piglet as a model for the 3-mo-old infant. Equal numbers of piglets (n = 8) were fed either the goat milk formula or the cow milk formula. The mineral composition of the prepared goat milk formula was higher than that of the prepared cow milk formula for most minerals, including calcium (75.1 vs. 56.7 mg/100 mL) but excluding iron, which was higher in the prepared cow milk formula (0.92 vs. 0.74 mg/100 mL). The amounts of calcium, phosphorus, and manganese absorbed by the piglets were significantly higher for the goat milk formula, whereas the amounts of zinc, iron, and magnesium absorbed were significantly higher for the cow milk formula. Apparent mineral absorption, relative to intake, was statistically higher in the cow milk formula for calcium and phosphorus, although the actual differences were very small (less than 1.3%). For copper, zinc, iron, and magnesium there was no significant difference between treatments in apparent mineral absorption, whereas for manganese, absorption was higher for the goat milk infant formula. The absolute mineral deposition was higher in piglets fed the goat milk formula for calcium, phosphorus, and manganese, whereas iron deposition was higher in the piglets fed cow milk formula. For all other minerals tested, there were no significant differences between treatments. The goat milk infant formula provided a pattern of mineral retention in the 3-wk-old piglet very similar to that of the adapted cow milk infant formula. The minor differences observed between the 2 appeared to be due to the different mineral contents of the 2 formulas.

A comparison of the neuromuscular blocking effects and reversibility of cisatracurium and atracurium

The neuromuscular blocking effects and the reversibility of cisatracurium 0.1 or 0.15 mg.kg-1 were compared with those of atracurium 0.5 mg.kg-1 during anaesthesia with propofol, nitrous oxide and isoflurane. Neuromuscular block was monitored using train-of-four stimulation while recording the mechanomyographic response of the adductor pollicis muscle. The block was either allowed to recover spontaneously or was antagonised with neostigmine 50 micrograms.kg-1 at 10% or 25% recovery of the first twitch of the train-of-four. The median times to maximum block were 2.7, 2.2 and 1.5 min following cisatracurium 0.1 and 0.15 mg.kg-1 and atracurium 0.5 mg.kg-1, respectively. After cisatracurium 0.1 mg.kg-1 had been given, the median time to recovery of the train-of-four ratio to 0.8 ('adequate recovery') was 74 min during spontaneous recovery, 48 min after reversal with neostigmine when the first twitch of the train-of-four had returned to 10% of control and 50 min after reversal when the first twitch of the train-of-four had returned to 25% of control. These times for cisatracurium 0.15 mg.kg-1 and atracurium 0.5 mg.kg-1 were 90, 66 and 57 min and 75, 56 and 54 min, respectively. Administration of neostigmine significantly shortened the time to adequate recovery for both drugs but there were no significant differences in the case of either neuromuscular blocking drug between the groups of patients given neostigmine at 10 or 25% recovery of the first twitch of the train-of-four.

Marked long-term decline in ambient CO mixing ratio in SE England, 1997-2014: evidence of policy success in improving air quality

Atmospheric CO at Egham in SE England has shown a marked and progressive decline since 1997, following adoption of strict controls on emissions. The Egham site is uniquely positioned to allow both assessment and comparison of 'clean Atlantic background' air and CO-enriched air downwind from the London conurbation. The decline is strongest (approximately 50 ppb per year) in the 1997-2003 period but continues post 2003. A 'local CO increment' can be identified as the residual after subtraction of contemporary background Atlantic CO mixing ratios from measured values at Egham. This increment, which is primarily from regional sources (during anticyclonic or northerly winds) or from the European continent (with easterly air mass origins), has significant seasonality, but overall has declined steadily since 1997. On many days of the year CO measured at Egham is now not far above Atlantic background levels measured at Mace Head (Ireland). The results are consistent with MOPITT satellite observations and 'bottom-up' inventory results. Comparison with urban and regional background CO mixing ratios in Hong Kong demonstrates the importance of regional, as opposed to local reduction of CO emission. The Egham record implies that controls on emissions subsequent to legislation have been extremely successful in the UK.

Is psychosocial and cognitive dysfunction misattributed to the virus in hepatitis C infection? Select psychosocial contributors identified

Chronic hepatitis C is associated with health-related quality of life and cognitive impairments, even in mild disease. Recent evidence demonstrating hepatitis C virus (HCV) neurotropism has strengthened a neuropathophysiological hypothesis. However, sample heterogeneity confounds study outcomes. A uniquely homogeneous cohort of Irish women, following an iatrogenic HCV outbreak, offers a rare opportunity to control for HCV chronicity and the virus' purported impact on quality of life and cognition. A multi site, three-group, cross-sectional design was employed. Noncirrhotic, iatrogenically infected women, developing either acute or chronic infection, were recruited from prospective tertiary-care liver clinics and the community. Well-matched healthy controls were also recruited. All participants completed a psychosocial survey and were invited to undergo a comprehensive neuropsychological test battery. Significantly distressed psychosocial symptom profiles were observed in those with an iatrogenic HCV exposure history, which was independent of viral chronicity. Chronic and cleared HCV cohorts were not differentiated from each other. Two distinct subgroups, demarcated along 'impaired' vs 'nonimpaired' quality-of-life reports, were clearly identified and logistic regression analysis identified depressed mood and cognitive fatigue, rather than viral status, as statistically significant predictors of group membership. Compared with matched controls, significant cognitive impairments were not observed in either HCV cohort. Our findings provide strong evidence of nonviral factors accounting for quality of life impairment in chronic HCV and they also appear to question existing reports of cognitive dysfunction in mild disease. Depressed mood and cognitive fatigue appear to be critical psychosocial mediators of reduced quality-of-life and we hypothesize that metabolite abnormalities reported in HCV samples may also be confounded by these factors, given the associated literature.

Exercise combined with Acceptance and Commitment Therapy compared with a standalone supervised exercise programme for adults with chronic pain: a randomised controlled trial

ABSTRACT

A prospective, 2-armed, parallel group randomised controlled trial (RCT) was conducted to compare the effectiveness of Acceptance and Commitment Therapy (ACT) combined with a supervised exercise programme with a supervised exercise programme alone for adults with chronic pain. One hundred seventy-five participants were individually randomised to receive either the combined Exercise and ACT (ExACT) intervention or supervised exercise alone. Those allocated to the ExACT group attended 8 weekly sessions with a psychologist based on the ACT approach, in addition to supervised exercise classes led by a physiotherapist. The control group attended weekly supervised exercise classes but did not take part in an ACT programme. Both groups were followed up postintervention and again after 12 weeks. The primary outcome was pain interference at 12-week follow-up. Estimates of treatment effects at follow-up were based on intention-to-treat analyses, implemented using a linear mixed-effects model. The findings of this RCT showed no difference in the effectiveness of ExACT, compared with a supervised exercise programme alone for the primary outcome pain interference at 12-week follow-up (mean difference -0.18, 95% confidence interval -0.84 to 0.48, P = 0.59, d = 0.11). ExACT group participants reported superior outcomes for pain self-efficacy, pain catastrophising, and committed action, compared with the control group, but there were no differences between the groups for other secondary outcomes or treatment process measures. Higher levels of treatment satisfaction and global impression of change were reported by ExACT group participants. Exercise combined with Acceptance and Commitment Therapy was not superior to a standalone supervised exercise programme for reducing pain interference in adults with chronic pain.

Exercise and Acceptance and Commitment Therapy for Chronic Pain: A Case Series with One-Year Follow-Up

INTRODUCTION

There is growing evidence to support Acceptance and Commitment Therapy (ACT) in the management of chronic pain. However, there is a need for further research evaluating ACT combined with physical exercise, and few studies have assessed the long-term impact of this type of intervention. This case series reports on the acceptability and impact of an ACT-based multidisciplinary pain management programme on a range of health outcomes in both the short and long-term.

METHODS

Seventy-three participants completed an 8-week group-based, pain management programme. The programme combined weekly sessions of ACT with education and exercise classes. Self-report outcome measures were completed at baseline, post-intervention and at one-year follow-up. The measures assessed pain intensity and interference, psychological distress, self-efficacy, pain acceptance, values-based action, pain catastrophizing, fear avoidance and healthcare utilization. Pedometers were worn to objectively measure physical activity. Data were analyzed using linear mixed modelling. Ethical approval for this study was granted by the Mater Misericordiae University Hospital (MMUH) Institutional Review Board (Reference 1/378/1541).

RESULTS

Eighty-six percent of respondents reported being satisfied with the intervention. Improvements were observed in most of the self-report outcomes post-intervention and many changes were maintained at one-year. There was also a significant increase in average daily step-count.

CONCLUSION

A pain management programme combining ACT with exercise appears to be an acceptable treatment option for people with chronic pain. While improvements were observed in both the short and long-term, further fully powered RCTs with long-term follow-up are required to test the effectiveness of this type of intervention.

Wellbeing and mental health outcomes amongst hospital healthcare workers during COVID-19

BACKGROUND

Global healthcare systems have been particularly impacted by the COVID-19 pandemic. Healthcare workers (HCWs) are widely reported to have experienced increased levels of baseline psychological distress relative to the general population, and the COVID-19 pandemic may have had an additive effect. However, previous studies are typically restricted to physicians and nurses with limited data available on hospital HCWs. We aimed to conduct a cross-sectional, psychological evaluation of Irish HCWs during COVID-19.

METHODS

HCWs across five adult acute level-4 Dublin-based hospitals completed an online survey of wellbeing and COVID-19 experience.

RESULTS

There were 1898 HCWs who commenced the survey representing 10% of the total employee base. The sample comprised nurses (33%), doctors (21%), Health and Social Care Professionals (HSCPs) (24%) and 'Other' disciplines (22%), and 81% identified as female. Clinical levels of depression, anxiety and PTSD symptoms were endorsed by 31%, 34% and 28% of respondents, respectively. Professional grouping effects included: nurses reporting significantly greater levels of COVID-19 exposure, infection, COVID-fear, moral injury, and post-traumatic distress; HSCPs were significantly less likely to report mood dysfunction. In terms of gender, males were significantly less likely to report negative pandemic experiences, low resilience, and significantly more likely to endorse 'minimal' depression, anxiety, and traumatic distress. Logistic regression modelling revealed mental health outcomes (depression, anxiety and PTSD symptoms) were associated with increased frontline exposure, fewer career years' experience, elevated pre-pandemic stress, and female gender.

DISCUSSION

To our knowledge, this is the largest evaluation of psychological wellbeing amongst HCWs in acute hospitals in the Dublin region. Our findings have implications for healthcare workforce wellbeing and future service delivery.

Measurements of δ13C in CH4 and using particle dispersion modeling to characterize sources of Arctic methane within an air mass

A stratified air mass enriched in methane (CH4) was sampled at ~600 m to ~2000 m altitude, between the north coast of Norway and Svalbard as part of the Methane in the Arctic: Measurements and Modelling campaign on board the UK's BAe-146-301 Atmospheric Research Aircraft. The approach used here, which combines interpretation of multiple tracers with transport modeling, enables better understanding of the emission sources that contribute to the background mixing ratios of CH4 in the Arctic. Importantly, it allows constraints to be placed on the location and isotopic bulk signature of the emission source(s). Measurements of δ13C in CH4 in whole air samples taken while traversing the air mass identified that the source(s) had a strongly depleted bulk δ13C CH4 isotopic signature of -70 (±2.1)‰. Combined Numerical Atmospheric-dispersion Modeling Environment and inventory analysis indicates that the air mass was recently in the planetary boundary layer over northwest Russia and the Barents Sea, with the likely dominant source of methane being from wetlands in that region.