1219 INFORMAL CAREGIVERS OF PEOPLE WITH PARKINSONISM IN THE PRIME-UK CROSS-SECTIONAL STUDY

Introduction

Many people with parkinsonism require care as the disease progresses with much provided unpaid by family and friends. Caring for someone can have a negative impact on physical and psychosocial wellbeing. Caregiver burden can impact ability to continue this role, which can precipitate hospitalisation or institutionalisation of the recipient.

Methods

In this single-site study, primary, informal caregivers, defined as those providing any care or support, were enrolled alongside the person with parkinsonism or individually. Self-reported questionnaires included the 22-item Zarit Burden Interview (ZBI), which can range from 0-88, with higher scores representing greater burden. Linear regression was used to explore the association between recipient characteristics/need and caregiver burden.

Results

Of 1,032 eligible patients approached, 813 participants indicated whether they had an informal caregiver (708) or not (105). 376 caregivers consented (53.1%), of whom 321 have returned questionnaires, with patient data available for 296. The median age of caregivers was 73.0 (range 27.0- 91.1 years), 237 (73.8%) female. 274 (85.4%) were the spouse/partner of the patient. 215 (67.0%) were the sole caregiver. The median time per week spent caring was 21 hours (interquartile range 7, 41 hours). 18 (5.6%) of caregivers provided 24-hour care daily and 113 (35.2%) had provided support for over 5 years. Median ZBI score was 17, (interquartile range 7-29). The care recipient’s duration of parkinsonism was associated with higher burden score (0.38 increase per year of parkinsonism; 95% CI 0.07, 0.69; p value 0.015), as was the time per week spent caring (0.16 increase for each additional hour; 95% CI 0.11, 0.20; p value <0.0001).

Conclusions

Many informal caregivers in this study were the sole caregiver and many were themselves older adults. Burden increased with increasing duration of parkinsonism and as time spent caring increased. This highlights the ongoing need to improve support for this group.

Dust, Sand, and Winds Within an Active Martian Storm in Jezero Crater

Rovers and landers on Mars have experienced local, regional, and planetary-scale dust storms. However, in situ documentation of active lifting within storms has remained elusive. Over 5-11 January 2022 (L_S 153°-156°), a dust storm passed over the Perseverance rover site. Peak visible optical depth was ∼2, and visibility across the crater was briefly reduced. Pressure amplitudes and temperatures responded to the storm. Winds up to 20 m s^-1 rotated around the site before the wind sensor was damaged. The rover imaged 21 dust-lifting events-gusts and dust devils-in one 25-min period, and at least three events mobilized sediment near the rover. Rover tracks and drill cuttings were extensively modified, and debris was moved onto the rover deck. Migration of small ripples was seen, but there was no large-scale change in undisturbed areas. This work presents an overview of observations and initial results from the study of the storm.

Global Vertical Distribution of Water Vapor on Mars: Results From 3.5 Years of ExoMars-TGO/NOMAD Science Operations

We present water vapor vertical distributions on Mars retrieved from 3.5 years of solar occultation measurements by Nadir and Occultation for Mars Discovery onboard the ExoMars Trace Gas Orbiter, which reveal a strong contrast between aphelion and perihelion water climates. In equinox periods, most of water vapor is confined into the low-middle latitudes. In aphelion periods, water vapor sublimated from the northern polar cap is confined into very low altitudes-water vapor mixing ratios observed at the 0-5 km lower boundary of measurement decrease by an order of magnitude at the approximate altitudes of 15 and 30 km for the latitudes higher than 50°N and 30-50°N, respectively. The vertical confinement of water vapor at northern middle latitudes around aphelion is more pronounced in the morning terminators than evening, perhaps controlled by the diurnal cycle of cloud formation. Water vapor is also observed over the low latitude regions in the aphelion southern hemisphere (0-30°S) mostly below 10-20 km, which suggests north-south transport of water still occurs. In perihelion periods, water vapor sublimated from the southern polar cap directly reaches high altitudes (>80 km) over high southern latitudes, suggesting more effective transport by the meridional circulation without condensation. We show that heating during perihelion, sporadic global dust storms, and regional dust storms occurring annually around 330° of solar longitude (L _S) are the main events to supply water vapor to the upper atmosphere above 70 km.

A meta-epidemiological study of bias in randomized clinical trials of open and laparoscopic surgery

BACKGROUND

Blinding, random sequence generation, and allocation concealment are established strategies to minimize bias in RCTs. Meta-epidemiological studies of drug trials have demonstrated exaggerated treatment effects in RCTs where such methods were not employed. As blinding is more difficult in surgical trials it is important to determine whether this applies to them. The study aimed to investigate this using systematic meta-epidemiological methods.

METHOD

The Cochrane Database of Systematic Reviews was searched for systematic reviews of RCTs that compared laparoscopic and open abdominal surgical procedures. Each review was then scrutinized to determine whether at least one of the included trials was blinded. Eligible reviews were updated and individual RCTs retrieved. Extracted data included the primary outcomes of interest (length of stay and complications), secondary outcomes and a risk of bias assessment. A multistep meta-regression analysis was then performed to obtain an overall difference in the reported outcome differences between trials that employed each bias-minimization strategy, and those that did not.

RESULTS

Some 316 RCTs were included, reporting on eight different procedures. Patient-blinded RCTs reported a smaller difference in length of stay between laparoscopic and open groups (difference of standardized mean differences -0·36 (95 per cent c.i. -0·73 to 0·00)) and complications (ratio of odds ratios 0·76 (95 per cent c.i. 0·61 to 0·93)). Blinding of postoperative carers and outcome assessors had similar effects.

CONCLUSION

Lack of blinding significantly altered the treatment effect estimates of RCTs comparing laparoscopic and open surgery. Blinding should be implemented in surgical RCTs where possible to avoid systematic bias.

The Mars Environmental Dynamics Analyzer, MEDA. A Suite of Environmental Sensors for the Mars 2020 Mission

NASA's Mars 2020 (M2020) rover mission includes a suite of sensors to monitor current environmental conditions near the surface of Mars and to constrain bulk aerosol properties from changes in atmospheric radiation at the surface. The Mars Environmental Dynamics Analyzer (MEDA) consists of a set of meteorological sensors including wind sensor, a barometer, a relative humidity sensor, a set of 5 thermocouples to measure atmospheric temperature at ∼1.5 m and ∼0.5 m above the surface, a set of thermopiles to characterize the thermal IR brightness temperatures of the surface and the lower atmosphere. MEDA adds a radiation and dust sensor to monitor the optical atmospheric properties that can be used to infer bulk aerosol physical properties such as particle size distribution, non-sphericity, and concentration. The MEDA package and its scientific purpose are described in this document as well as how it responded to the calibration tests and how it helps prepare for the human exploration of Mars. A comparison is also presented to previous environmental monitoring payloads landed on Mars on the Viking, Pathfinder, Phoenix, MSL, and InSight spacecraft.

Quality of life, function and disability in individuals with chronic ankle symptoms: a cross-sectional online survey

BACKGROUND

Chronic ankle conditions affect approximately 20% of Australian adults. Although there is a plethora of research on chronic hip and knee conditions, there is limited understanding of the impact of ankle problems. Thus, the significance of chronic ankle conditions is not clear. The aim of this study was to compare self-reported function, disability, instability, physical activity and quality of life (QoL) between adults with and without ankle symptoms. A secondary aim was to explore factors associated with QoL.

METHOD

Individuals with symptoms of ankle pain and stiffness (symptomatic individuals) and controls with no ankle pain or stiffness (asymptomatic individuals) completed a cross-sectional online survey. The survey included the Ankle Osteoarthritis Scale (AOS), Foot and Ankle Ability Measure (FAAM), Cumberland Ankle Instability Tool (CAIT), International Physical Activity Questionnaire (IPAQ), Assessment of QoL (AQoL-6D), and questions about ankle injury history.

RESULTS

A total of 394 individuals (270 symptomatic and 124 asymptomatic) with mean age of 48.8 (standard deviation (SD): 12.1) years and body mass index of 28.7 (7.7) kgm- 2 completed the survey. Standardized mean differences (SMD) were large to very large (1.45 to 3.20) for greater disability (AOS) and instability (CAIT), and poorer function (FAAM) in symptomatic compared to asymptomatic individuals. Individuals with ankle symptoms had higher body mass index and lower QoL (medium effect: SMD > 1). There were no differences in self-report physical activity between groups. Lower activities of daily living (ADL) function (FAAM-ADL) best explained QoL in a multiple regression model (R2 = 0.66, p = 0.001).

CONCLUSION

Individuals with ankle symptoms reported ankle instability, greater disability, compromised function and worse QoL compared to asymptomatic individuals. There was a strong relationship between ankle function and QoL. Ankle-specific ability during ADL best explained the reduced QoL in individuals with ankle symptoms. Clinicians and researchers should consider ankle function as an antecedent to poorer QoL in patients who have ankle symptoms.

Supercomputer-Based Ensemble Docking Drug Discovery Pipeline with Application to Covid-19

We present a supercomputer-driven pipeline for in-silico drug discovery using enhanced sampling molecular dynamics (MD) and ensemble docking. We also describe preliminary results obtained for 23 systems involving eight protein targets of the proteome of SARS CoV-2. THe MD performed is temperature replica-exchange enhanced sampling, making use of the massively parallel supercomputing on the SUMMIT supercomputer at Oak Ridge National Laboratory, with which more than 1ms of enhanced sampling MD can be generated per day. We have ensemble docked repurposing databases to ten configurations of each of the 23 SARS CoV-2 systems using AutoDock Vina. We also demonstrate that using Autodock-GPU on SUMMIT, it is possible to perform exhaustive docking of one billion compounds in under 24 hours. Finally, we discuss preliminary results and planned improvements to the pipeline, including the use of quantum mechanical (QM), machine learning, and AI methods to cluster MD trajectories and rescore docking poses.

Effects of the MY34/2018 Global Dust Storm as Measured by MSL REMS in Gale Crater

The Rover Environmental Monitoring Station (REMS) instrument that is onboard NASA's Mars Science Laboratory (MSL) Curiosity rover. REMS has been measuring surface pressure, air and ground brightness temperature, relative humidity, and UV irradiance since MSL's landing in 2012. In Mars Year (MY) 34 (2018) a global dust storm reached Gale Crater at L_s ~190°. REMS offers a unique opportunity to better understand the impact of a global dust storm on local environmental conditions, which complements previous observations by the Viking landers and Mars Exploration Rovers. All atmospheric variables measured by REMS are strongly affected albeit at different times. During the onset phase, the daily maximum UV radiation decreased by 90% between sols 2075 (opacity ~1) and 2085 (opacity ~8.5). The diurnal range in ground and air temperatures decreased by 35K and 56K, respectively, with also a diurnal-average decrease of ~2K and 4K respectively. The maximum relative humidity, which occurs right before sunrise, decreased to below 5%, compared with pre-storm values of up to 29%, due to the warmer air temperatures at night while the inferred water vapor abundance suggests an increase during the storm. Between sols 2085 and 2130, the typical nighttime stable inversion layer was absent near the surface as ground temperatures remained warmer than near-surface air temperatures. Finally, the frequency-domain behavior of the diurnal pressure cycle shows a strong increase in the strength of the semidiurnal and terdiurnal modes peaking after the local opacity maximum, also suggesting differences in the dust abundance inside and outside Gale.

Network meta-analysis of surgical management of gastro-oesophageal reflux disease in adults

BACKGROUND

Proton pump inhibitors are the mainstay of treatment for gastro-oesophageal reflux disease, but are associated with ongoing costs and side-effects. Antireflux surgery is cost-effective and is preferred by many patients. A total (360^o or Nissen) fundoplication is the traditional procedure, but other variations including partial fundoplications are also commonly performed, with the aim of achieving durable reflux control with minimal dysphagia. Many RCTs and some pairwise meta-analyses have compared some of these procedures but there is still uncertainty about which, if any, is superior. Network meta-analysis allows multiple simultaneous comparisons and robust synthesis of the available evidence in these situations. A network meta-analysis comparing all antireflux procedures was performed to identify which has the most favourable outcomes at short-term (3-12 months), medium-term (1-5 years) and long-term (10 years and more than 10 years) follow-up.

METHODS

Article databases were searched systematically for all eligible RCTs. Primary outcomes were quality-of-life measures and dysphagia. Secondary outcomes included reflux symptoms, pH studies and complications.

RESULTS

Fifty-one RCTs were included, involving 5357 patients and 14 different treatments. Posterior partial fundoplication ranked best in terms of reflux symptoms, and caused less dysphagia than most other interventions including Nissen fundoplication. This was consistent across all time points and outcome measures.

CONCLUSION

Posterior partial fundoplication provides the best balance of long-term, durable reflux control with less dysphagia, compared with other treatments.

Techniques for Measurement of Oxygen Consumption Rates of Hepatocytes during Attachment and Post-Attachment

Three techniques for measuring oxygen consumption rate (OCR) of cultured cells relevant to the development of bioartificial liver devices are reported. In an oxystat apparatus, HepG2 cells immobilised on Cytodex 3 microcarriers at a concentration of 106 cells ml-1 had a mean OCR of 0.7 nmol s-1/106 cells. The OCR decreased with increasing cell density, a characteristic previously reported for other cell lines. Rat hepatocytes immobilised on single collagen layers in a flow cell and challenged with ammonia had a mean OCR of 0.59 nmol s-1/106 cells. A novel two-compartment oxystat system was used to determine the OCR of rat hepatocytes during the attachment phase. OCR declined from 1.0 nmol s-1/106 immediately after seeding to 0.7 nmol s-1/106 cells at nine hours. The low OCR for HepG2 reflects loss of certain oxygen dependent metabolic pathways. The OCR measured for rat hepatocytes during and post-attachment are significantly higher than those reported elsewhere and have major implications for the development of bioartificial liver devices.

The Vertical Dust Profile over Gale Crater, Mars

We create a vertically coarse, but complete, vertical profile of dust mixing ratio from the surface to the upper atmosphere over Gale Crater, Mars, using the frequent joint atmospheric observations of the orbiting Mars Climate Sounder (MCS) and the Mars Science Laboratory (MSL) Curiosity rover. Using these data and an estimate of planetary boundary layer (PBL) depth from the MarsWRF general circulation model, we divide the vertical column into three regions. The first region is the Gale Crater PBL, the second is the MCS-sampled region, and the third is between these first two. We solve for a well-mixed dust mixing ratio within this third (middle) layer of atmosphere to complete the profile. We identify a unique seasonal cycle of dust within each atmospheric layer. Within the Gale PBL, dust mixing ratio maximizes near southern hemisphere summer solstice (L_s = 270°) and minimizes near winter solstice (L_s = 90-100°) with a smooth sinusoidal transition between them. However, the layer above Gale Crater and below the MCS-sampled region more closely follows the global opacity cycle and has a maximum in opacity near L_s = 240° and exhibits a local minimum (associated with the "solsticial pause" in dust storm activity) near L_s = 270°. With knowledge of the complete vertical dust profile, we can also assess the frequency of high-altitude dust layers over Gale. We determine that 36% of MCS profiles near Gale Crater contain an "absolute" high-altitude dust layer wherein the dust mixing ratio is the maximum in the entire vertical column.

Composite infrared spectrometer (CIRS) on Cassini: publisher's note

This publisher's note renumbers the reference list in Appl. Opt.56, 5274 (2017)APOPAI0003-693510.1364/AO.56.005274.

Composite infrared spectrometer (CIRS) on Cassini

The Cassini spacecraft orbiting Saturn carries the composite infrared spectrometer (CIRS) designed to study thermal emission from Saturn and its rings and moons. CIRS, a Fourier transform spectrometer, is an indispensable part of the payload providing unique measurements and important synergies with the other instruments. It takes full advantage of Cassini's 13-year-long mission and surpasses the capabilities of previous spectrometers on Voyager 1 and 2. The instrument, consisting of two interferometers sharing a telescope and a scan mechanism, covers over a factor of 100 in wavelength in the mid and far infrared. It is used to study temperature, composition, structure, and dynamics of the atmospheres of Jupiter, Saturn, and Titan, the rings of Saturn, and surfaces of the icy moons. CIRS has returned a large volume of scientific results, the culmination of over 30 years of instrument development, operation, data calibration, and analysis. As Cassini and CIRS reach the end of their mission in 2017, we expect that archived spectra will be used by scientists for many years to come.

Network meta-analysis of the effect of preoperative carbohydrate loading on recovery after elective surgery

BACKGROUND

Three meta-analyses have summarized the effects of preoperative carbohydrate administration on postoperative outcomes in adult patients undergoing elective surgery. However, these studies could not account for the different doses of carbohydrate administered and the different controls used. Multiple-treatments meta-analysis allows robust synthesis of all available evidence in these situations.

METHODS

Article databases were searched systematically for RCTs comparing preoperative carbohydrate administration with water, a placebo drink, or fasting. A four-treatment multiple-treatments meta-analysis was performed comparing two carbohydrate dose groups (low, 10-44 g; high, 45 g or more) with two control groups (fasting; water or placebo). Primary outcomes were length of hospital stay and postoperative complication rate. Secondary outcomes included postoperative insulin resistance, vomiting and fatigue.

RESULTS

Some 43 trials involving 3110 participants were included. Compared with fasting, preoperative low-dose and high-dose carbohydrate administration decreased postoperative length of stay by 0·4 (95 per cent c.i. 0·03 to 0·7) and 0·2 (0·04 to 0·4) days respectively. There was no significant decrease in length of stay compared with water or placebo. There was no statistically significant difference in the postoperative complication rate, or in most of the secondary outcomes, between carbohydrate and control groups.

CONCLUSION

Carbohydrate loading before elective surgery conferred a small reduction in length of postoperative hospital stay compared with fasting, and no benefit in comparison with water or placebo.

Photosynthetic responses of a dominant C4 grass to an experimental heat wave are mediated by soil moisture

Extreme heat waves and drought are predicted to increase in frequency and magnitude with climate change. These extreme events often co-occur, making it difficult to separate their direct and indirect effects on important ecophysiological and carbon cycling processes such as photosynthesis. Here, we assessed the independent and interactive effects of experimental heat waves and drought on photosynthesis in Andropogon gerardii, a dominant C₄ grass in a native mesic grassland. We experimentally imposed a two-week heat wave at four intensity levels under two contrasting soil moisture regimes: a well-watered control and an extreme drought. There were three main findings from this study. First, the soil moisture regimes had large effects on canopy temperature, leading to extremely high temperatures under drought and low temperatures under well-watered conditions. Second, soil moisture mediated the photosynthetic response to heat; heat reduced photosynthesis under the well-watered control, but not under the extreme drought treatment. Third, the effects of heat on photosynthesis appeared to be driven by a direct thermal effect, not indirectly through other environmental or ecophysiological variables. These results suggest that while photosynthesis in this dominant C₄ grass is sensitive to heat stress, this sensitivity can be overwhelmed by extreme drought stress.

Photophysics of GFP-related chromophores imposed by a scaffold design

In this paper, a rigid scaffold imposes the photophysics of chromophores with a benzylidene imidazolidinone core by mimicking the β-barrel structure of the green fluorescent protein (GFP) and its analogs.

The effect of flexor digitorum profundus tendon shortening on jersey finger surgical repair: a cadaveric biomechanical study

Delayed diagnosis of jersey finger injuries often results in retraction of the flexor digitorum profundus tendon. Current practice recommends limiting tendon advancement to 1 cm in delayed repairs. The purpose of this study was to investigate the biomechanical consequences of tendon shortening on the force required to form a fist. The flexor digitorum profundus muscle was isolated in ten cadaveric forearms and the force required to form a fist was recorded. Simulated jersey finger injuries to the ring finger were then created and repaired. The forces required to pull the fingertips to the palm after serial tendon advancements were measured. There was a near linear increase in the force required for making a fist with shortening up to 2.5 cm. The force required to make a fist should be taken into account when considering the limit of 'safe' tendon shortening in delayed repair of jersey finger injuries.

Quantifying not only bone loss, but also soft tissue swelling, in a murine inflammatory arthritis model using micro-computed tomography

In rodent models of inflammatory arthritis, bone erosion has been non-invasively assessed by micro-computed tomography (micro-CT). However, non-invasive assessments of paw swelling (oedema) are still based on clinical grading by visual evaluation, or measurements by callipers, not always reliable for the tiny mouse paws. The aim of this work was to demonstrate a novel straightforward 3D micro-CT analysis protocol capable of quantifying not only joint bone erosion, but also soft tissue swelling, from the same scans, in a rodent inflammatory arthritis model. Balb/c mice were divided into two groups: collagen antibody-induced arthritis (CAIA) and CAIA treated with prednisolone, the latter reflecting an established treatment in human rheumatoid arthritis. Clinical paw scores were recorded. On day 10, front paws were assessed by micro-CT and histology. Micro-CT measurements included paw volume (bone and soft tissue together) and bone volume at the radiocarpal joint, and bone volume from the radiocarpal to the metacarpophalangeal joint. Micro-CT analysis revealed significantly lower paw volume (−36%, P < 0.01) and higher bone volume (+17%, P < 0.05) in prednisolone-treated CAIA mice compared with untreated CAIA mice. Paw volume and bone volume assessed by micro-CT correlated significantly with clinical and histological scores (|r| > 0.5, P < 0.01). Untreated CAIA mice showed significantly higher clinical scores, higher inflammation levels histologically, cartilage and bone degradation, and pannus formation, compared with treated mice (P < 0.01). The presented novel micro-CT analysis protocol enables 3D-quantification of paw swelling at the micrometre level, along with the typically assessed bone erosion, using the same images/scans, without altering the scanning procedure or using contrast agents.

A new era of global surgery

Global health care must have strong surgical input

Strong water isotopic anomalies in the martian atmosphere: probing current and ancient reservoirs

We measured maps of atmospheric water (H2O) and its deuterated form (HDO) across the martian globe, showing strong isotopic anomalies and a significant high deuterium/hydrogen (D/H) enrichment indicative of great water loss. The maps sample the evolution of sublimation from the north polar cap, revealing that the released water has a representative D/H value enriched by a factor of about 7 relative to Earth's ocean [Vienna standard mean ocean water (VSMOW)]. Certain basins and orographic depressions show even higher enrichment, whereas high-altitude regions show much lower values (1 to 3 VSMOW). Our atmospheric maps indicate that water ice in the polar reservoirs is enriched in deuterium to at least 8 VSMOW, which would mean that early Mars (4.5 billion years ago) had a global equivalent water layer at least 137 meters deep.

Medication errors reported to U.S. Poison Control Centers, 2000-2012

CONTEXT

Previous studies of medication errors have largely focused on healthcare facilities and have not reported generalizable national trends among out-of-hospital medication errors.

OBJECTIVE

We sought to understand U.S. trends in medication errors, including the age-related risks, the involved medications, and the medical outcomes.

MATERIALS AND METHODS

We performed a retrospective analysis of National Poison Data System (NPDS) data from the American Association of Poison Control Centers for years 2000-2012. Medication error cases were analyzed by age, gender, pharmaceutical involved, substance rank, dosing error type, management site, level of healthcare received, and medical outcome. Trends in medication error rates were analyzed using Poisson regression.

RESULTS

From 2000 to 2012, the NPDS recorded 2,913,924 calls reporting unintentional pharmaceutical-related errors that met inclusion criteria. Non-healthcare facility calls comprised 99.2% calls related to unintentional therapeutic errors. Eighty-seven percent of medication errors were managed on site. The annual medication error rate for all callers per 10,000 U.S. population increased significantly (p < 0.0001) by 69.8% from 2000 (4.98 calls per 10,000 population) to 2012 (8.46 calls per 10,000 population). Among adults aged 20 years and older, age was positively correlating (r = 0.96) with the rate of medication error. Analgesics were the most frequent pharmaceutical class involved in medication errors for ages 6-49 (N = 221,061). Among ages 20-49 years, opioid-related medication errors decreased by 7.9% from 2010 to 2012. Cardiovascular drugs were the leading source of injury among all ages (N = 14,440) and also the leading pharmaceutical class involved in medication errors among adults 50 years and older (N = 187,760).

CONCLUSION

Medication errors continue to be a source of preventable injury with increasing incidence across the out-of-hospital population.

Analysis of parameters influencing the release of antibiotics mixed with bone grafting material using a reliable mixing procedure

Local infections arising from fracture fixation, defect reconstruction or joint replacement can cause extreme pain and impaired healing, lead to revision operations, prolong hospital stay and increase costs. Treatment options including prophylaxis are afforded by the use of grafts and biomaterials loaded with antibiotics. These can produce local therapeutic concentrations with a reduced systemic concentration and reduced systemic side-effects. Patient-specific loading of osteogenic graft materials with antibiotic could be an important option for orthopaedic surgeons. A local therapeutic concentration must be available for the desired duration and cytotoxic effects must be kept within an acceptable range. The present study investigates a simple and reliable mixing procedure that could be used for the perioperative combination of antibiotic powders and solutions with bone grafting materials. The potential influence of concentration and sampling regime on the release kinetics of gentamicin, tobramycin and vancomycin was studied over a period of 56days and potency and cytotoxicity were evaluated. In all treatment groups, gentamicin and tobramycin were completely released within 3days whilst vancomycin was released over a period of 14days. The results clearly show that the main parameter influencing release is the molecular weight of the drug. Growth of Staphylococcus aureus was inhibited in all 3 treatment groups for at least 3days. Cell viability and alkaline phosphatase activity of primary osteoblast-like cells were not significantly affected by the antibiotic concentrations obtained from the elution experiments. Bone grafting is an established component of surgery for bone defect filling and for biological stimulation of healing. Patient-specific enhancement of such procedures by incorporation of antibiotics for infection prevention or by addition of cytokines for promotion of impaired healing or for treatment of critical size defects will be a relevant issue in the future.

Characteristics of foot structure and footwear associated with hallux valgus: a systematic review

OBJECTIVE

Factors associated with the development of hallux valgus (HV) are multifactorial and remain unclear. The objective of this systematic review and meta-analysis was to investigate characteristics of foot structure and footwear associated with HV.

DESIGN

Electronic databases (Medline, Embase, and CINAHL) were searched to December 2010. Cross-sectional studies with a valid definition of HV and a non-HV comparison group were included. Two independent investigators quality rated all included papers. Effect sizes and 95% confidence intervals (CIs) were calculated (standardized mean differences (SMDs) for continuous data and risk ratios (RRs) for dichotomous data). Where studies were homogeneous, pooling of SMDs was conducted using random effects models.

RESULTS

A total of 37 papers (34 unique studies) were quality rated. After exclusion of studies without reported measurement reliability for associated factors, data were extracted and analysed from 16 studies reporting results for 45 different factors. Significant factors included: greater first intermetatarsal angle (pooled SMD = 1.5, CI: 0.88-2.1), longer first metatarsal (pooled SMD = 1.0, CI: 0.48-1.6), round first metatarsal head (RR: 3.1-5.4), and lateral sesamoid displacement (RR: 5.1-5.5). Results for clinical factors (e.g., first ray mobility, pes planus, footwear) were less conclusive regarding their association with HV.

CONCLUSIONS

Although conclusions regarding causality cannot be made from cross-sectional studies, this systematic review highlights important factors to monitor in HV assessment and management. Further studies with rigorous methodology are warranted to investigate clinical factors associated with HV.

Germline mutation of Brca1 alters the fate of mammary luminal cells and causes luminal-to-basal mammary tumor transformation

Breast cancer developed in familial BRCA1 mutation carriers bears striking similarities to sporadic basal-like breast tumors. The mechanism underlying the function of BRCA1 in suppressing basal-like breast cancer remains unclear. We previously reported that the deletion of p18(Ink4c) (p18), an inhibitor of G1 cyclin Ds-dependent CDK4 and CDK6, stimulates mammary luminal progenitor cell proliferation and leads to spontaneous luminal tumor development. We report here that germline mutation of Brca1 in p18-deficient mice blocks the increase of luminal progenitor cells, impairs luminal gene expression and promotes malignant transformation of mammary tumors. Instead of the luminal mammary tumors developed in p18 single-mutant mice, mammary tumors developed in the p18;Brca1 mice, similar to breast cancer developed in familial BRCA1 carriers, exhibited extensive basal-like features and lost the remaining wild-type allele of Brca1. These results reveal distinct functions of the RB and BRCA1 pathways in suppressing luminal and basal-like mammary tumors, respectively. These results also suggest a novel mechanism--causing luminal-to-basal transformation--for the development of basal-like breast cancer in familial BRCA1 carriers and establish a unique mouse model for developing therapeutic strategies to target both luminal and basal-like breast cancers.

Assessment of axial bone rigidity in rats with metabolic diseases using CT-based structural rigidity analysis

Objectives

This study aims to assess the correlation of CT-based structural rigidity analysis with mechanically determined axial rigidity in normal and metabolically diseased rat bone.

Methods

A total of 30 rats were divided equally into normal, ovariectomized, and partially nephrectomized groups. Cortical and trabecular bone segments from each animal underwent micro-CT to assess their average and minimum axial rigidities using structural rigidity analysis. Following imaging, all specimens were subjected to uniaxial compression and assessment of mechanically-derived axial rigidity.

Results

The average structural rigidity-based axial rigidity was well correlated with the average mechanically-derived axial rigidity results (R2 = 0.74). This correlation improved significantly (p < 0.0001) when the CT-based Structural Rigidity Analysis (CTRA) minimum axial rigidity was correlated to the mechanically-derived minimum axial rigidity results (R2 = 0.84). Tests of slopes in the mixed model regression analysis indicated a significantly steeper slope for the average axial rigidity compared with the minimum axial rigidity (p = 0.028) and a significant difference in the intercepts (p = 0.022). The CTRA average and minimum axial rigidities were correlated with the mechanically-derived average and minimum axial rigidities using paired t-test analysis (p = 0.37 and p = 0.18, respectively).

Conclusions

In summary, the results of this study suggest that structural rigidity analysis of micro-CT data can be used to accurately and quantitatively measure the axial rigidity of bones with metabolic pathologies in an experimental rat model. It appears that minimum axial rigidity is a better model for measuring bone rigidity than average axial rigidity.

Assessment of axial bone rigidity in rats with metabolic diseases using CT-based structural rigidity analysis

Objectives

This study aims to assess the correlation of CT-based structural rigidity analysis with mechanically determined axial rigidity in normal and metabolically diseased rat bone.

Methods

A total of 30 rats were divided equally into normal, ovariectomized, and partially nephrectomized groups. Cortical and trabecular bone segments from each animal underwent micro-CT to assess their average and minimum axial rigidities using structural rigidity analysis. Following imaging, all specimens were subjected to uniaxial compression and assessment of mechanically-derived axial rigidity.

Results

The average structural rigidity-based axial rigidity was well correlated with the average mechanically-derived axial rigidity results (R² = 0.74). This correlation improved significantly (p < 0.0001) when the CT-based Structural Rigidity Analysis (CTRA) minimum axial rigidity was correlated to the mechanically-derived minimum axial rigidity results (R² = 0.84). Tests of slopes in the mixed model regression analysis indicated a significantly steeper slope for the average axial rigidity compared with the minimum axial rigidity (p = 0.028) and a significant difference in the intercepts (p = 0.022). The CTRA average and minimum axial rigidities were correlated with the mechanically-derived average and minimum axial rigidities using paired t-test analysis (p = 0.37 and p = 0.18, respectively).

Conclusions

In summary, the results of this study suggest that structural rigidity analysis of micro-CT data can be used to accurately and quantitatively measure the axial rigidity of bones with metabolic pathologies in an experimental rat model. It appears that minimum axial rigidity is a better model for measuring bone rigidity than average axial rigidity.

Long-term open-label study of tanezumab for moderate to severe osteoarthritic knee pain

OBJECTIVE

This study was designed to evaluate the long-term safety and effectiveness of repeated doses of the humanized anti-nerve growth factor antibody, tanezumab, during open-label treatment of patients with OA knee pain.

DESIGN

The current study (clinicaltrials.gov identifier: NCT00399490) was a multicenter, phase II, open-label, multiple-dose extension of an earlier randomized clinical trial. All patients (N=281) received infusions of tanezumab 50μg/kg on Days 1 and 56 with subsequent doses administered at 8-week intervals (up to a total of eight infusions). The primary endpoint of this study was safety. Effectiveness evaluations included overall knee pain, Western Ontario and McMaster Universities Osteoarthritis (WOMAC) index subscales, and subject global assessment (SGA) of response to therapy on 0-100 point visual analog scales.

RESULTS

Repeated administration of tanezumab resulted in a low incidence of treatment-related adverse events (AEs; 7.5%). The rate of serious AEs was also low (2.8%) with none considered treatment-related. Few AEs of abnormal peripheral sensation were reported; hypoesthesia was reported by nine patients (3.2%), paresthesia by seven patients (2.5%), and hyperesthesia, peripheral neuropathy, and sensory disturbance were each reported by one patient (0.4% for each). Most AEs of abnormal peripheral sensation were rated as mild (95%) and the majority (65%) resolved before study completion. At Week 8, overall knee pain and SGA improved from baseline by a mean (± standard error) of -12.8 (±1.78) and 8.0 (±1.66), respectively. Similar improvements occurred for WOMAC subscales.

CONCLUSIONS

Repeated injections of tanezumab in patients with moderate to severe knee OA provide continued pain relief and improved function with a low incidence of side effects. Additional studies to define the efficacy and duration of pain reduction and to provide a more complete assessment of long-term safety are warranted.

Measurement of Mechanical Properties of Single and Multilayered Nitride thin Films Prepared by Cathodic Arc Deposition

Mechanical properties of thin films differ significantly from those of bulk materials due to the effects of interfaces, microstructure and thick underlying substrates. In this study we will present the results of nanoindentation tests to evaluate mechanical properties of nitride (TiN, ZrN, CrN, TiCN and TiAlN) thin films. Films were coated on steel substrates using cathodic arc deposition technique. Surface morphology and roughness of the samples are investigated using atomic force microscopy (AFM). Films were also characterized by x-ray diffraction (XRD) technique. Nanoindentation technique along with AFM and XRD methods are very useful for characterizing hard thin coatings.

Different stages of rheumatoid arthritis: features of the synovium in the preclinical phase

BACKGROUND

The aetiology of rheumatoid arthritis (RA), a prototype immune-mediated inflammatory disorder, is poorly understood. It is currently unknown whether the disease process starts in the synovium, the primary target of RA, or at other sites in the body.

OBJECTIVE

To examine, in a prospective study, the presence of synovitis in people with an increased risk of developing RA.

METHODS

Thirteen people without evidence of arthritis, who were positive for IgM rheumatoid factor and/or anticitrullinated protein antibodies, were included in the study. To evaluate synovial inflammatory changes, all participants underwent dynamic contrast-enhanced MRI and arthroscopic synovial biopsy sampling of a knee joint at inclusion. Results were compared with knee MRI data and synovial biopsy data of 6 and 10 healthy controls, respectively.

RESULTS

MRI findings evaluated by measurement of maximal enhancement, rate of enhancement, synovial volume and enhancement shape curve distribution were similar between the autoantibody-positive subjects and the healthy controls. Consistent with these findings, all but one autoantibody-positive subject showed very low scores for phenotypic markers, adhesion molecules and vascularity, all in the same range as those in normal controls. The one person with higher scores had patellofemoral joint space narrowing.

CONCLUSION

Subclinical inflammation of the synovium does not coincide with the appearance of serum autoantibodies during the pre-RA stage. Thus, systemic autoimmunity precedes the development of synovitis, suggesting that a 'second hit' is involved. This study supports the rationale for exploring preventive strategies aimed at interfering with the humoral immune response before synovial inflammation develops.

Epiflex(®) a new decellularised human skin tissue transplant: manufacture and properties

The manufacture and initial testing of a new human tissue transplant is described. Epiflex(®) is a human acellular dermis transplant that is manufactured from skin recovered from screened consenting donors according to validated and approved methods. The transplant is approved as a drug in Germany. The safety, stability and usability of the transplant are discussed with respect to the results of sterility, residual moisture content and rehydration tests. Histological and confocal laser scanning microscopy experiments and analysis of oxygen and water vapour permeability demonstrate that the native extracellular matrix structure and transport properties of human connective tissue are retained in the transplant. Results from initial clinical investigations suggest that Epiflex(®) can be used successfully in the treatment of burns, hypertrophic scars and as a transplant seeded with autologous dermal fibroblasts for soft-tissue regeneration in settings with wound healing problems following multi-modal treatments for sarcomas of the extremities.

Systematic review of tumour number and outcome after radical treatment of colorectal liver metastases

Background

Resection of colorectal liver metastases (CLMs) is potentially curative but the effect of tumour number on prognosis is uncertain. This study compared the prognosis after resection and/or ablation of between one and three, or four or more CLMs.

Methods

A systematic literature review from January 2000 to June 2008 was performed. Study selection and data extraction were standardized, and analysis included assessment of methodological quality, heterogeneity and bias. Main outcomes were 3- and 5-year survival. A meta-analysis comparing radical treatment in the two groups was performed using the hazard ratio for overall survival.

Results

Of 1307 studies screened, 46 (9934 patients) were included in the analysis. Methodological quality was variable, and there was significant heterogeneity and reporting bias. The overall 5-year survival rate after radical treatment ranged from 7 to 58 per cent. Pooled hazard ratio for overall survival was 1·67 (95 per cent confidence interval 1·43 to 1·95; P &lt; 0·001). Median reported 5-year survival for patients with four or more CLMs was 17·1 per cent.

Conclusion

Radical treatment of more than three CLMs results in poorer overall survival. Nevertheless, 5-year survival is achievable and the number of lesions should not, of itself, be used to exclude patients from surgery.

Effect of intra-articular infliximab on synovial membrane pathology in a patient with a seronegative spondyloarthropathy

OBJECTIVE

To demonstrate the efficacy of intra-articular infliximab in a patient with a persistent monarthritis who had previously had two arthroscopic synovectomies with limited success, and to determine the effect of intra-articular infliximab on synovial membrane pathology

METHOD

Arthroscopic synovial biopsy specimens were collected before and after treatment with intra-articular infliximab. The synovial tissue was stained for a range of inflammatory cell subsets, cell adhesion molecules and cytokines using immunohistochemical techniques and quantified using digital image analysis and a semiquantitative scoring method.

RESULTS

Clinical improvement in the knee synovitis was seen after the first two intra-articular infliximab treatments, with a sustained clinical remission lasting for more than 12 months after the third treatment. Significant changes in cellular infiltration and expression of cytokines and cell adhesion molecules occurred as a result of treatment with intra-articular infliximab, with a reduction in some but not all cells in the inflammatory infiltrate, as well as a reduction in the expression of cell adhesion molecules (intercellular adhesion molecule-1 and vascular adhesion molecule-1) and production of cytokines (interleukin 1beta and tumour necrosis factor alpha).

CONCLUSION

Intra-articular infliximab administration is a viable treatment for a persistent monarthritis resistant to other treatment options and can successfully modulate the inflammatory milieu within the synovial membrane.