Evaluation of Potential Low-stress Handling Methods in Crl:CDSD Rats (Rattus norvegicus).

Low-stress handling methods have been studied in detail in mice, but relatively little research exists concerning preferred handling methods in rats. Most recommendations for low-stress handling of rats have been extrapolated from the mouse literature, despite known differences in handler interaction between the 2 species. The goal of the current study was to evaluate common methods of handling in rats, including application of recognized, low-stress handling methods from other species to rats, in order to determine relative stress levels associated with the handling methods. Seventy male and 70 female, 8-wk-old, Crl:CDSD rats, were housed either individually or in pairs, and were handled weekly or daily using one of the following methods: encircling of the torso (standard thoracic hold), handled using a tunnel, handled using a protective bite glove, handled using a soft paper towel, or tickled prior to being handled by the torso ( n = 10 per sex per treatment group). Body weight and clinical observations were scored at each handling session, abbreviated functional observation batteries were performed every other week, and an interaction test and hematology were conducted prior to study and on the day of study termination. Rats that were socially housed and handled weekly using the standard thoracic hold showed the least evidence of stress, while those that were singly housed and handled weekly using a protective bite glove or tunnel showed the highest level of stress. These effects were predominantly seen in males. This study suggests that standard low-stress handling methods used for other species may not be optimal for rats, and that additional research is needed to identify alternative methods to the standard thoracic hold that would further reduce stress during handling in rats.

Is there a difference in the analgesic response to intra-articular bupivacaine injection in people with knee osteoarthritis pain with or without central sensitisation? Protocol of a feasibility randomised controlled trial.

INTRODUCTION: Pain is the main symptom of osteoarthritis (OA) with approximately 50% of patients reporting moderate-to-severe pain. Total knee replacement (TKR) is the ultimate treatment option to alleviate pain in knee OA. Nevertheless, TKR does not provide complete relief for all as approximately 20% of patients experience chronic postoperative pain. Painful peripheral stimuli may alter the central nociceptive pathways leading to central sensitisation that can influence treatment response in patients with OA. Currently, there is no objective protocol for detecting whether a patient will respond to a given treatment. Therefore, there is a need for a better mechanistic understanding of individual factors affecting pain relief, consequently informing personalised treatment guidelines. The purpose of this research is to examine the feasibility of conducting a full-scale mechanistic clinical trial in painful knee OA investigating the analgesic response to intra-articular bupivacaine between those with or without evidence of central sensitisation. METHODS AND ANALYSIS: The Understanding Pain mechanisms in KNEE osteoarthritis (UP-KNEE) study is a feasibility, double-blinded, placebo-controlled randomised parallel study in participants with radiographically defined knee OA and with self-reported chronic knee pain. The study involves the following assessments: (1) a suite of psychometric questionnaires; (2) quantitative sensory testing; (3) magnetic resonance imaging (MRI) scan of the knee and brain; (4) a 6-minute walk test; and (5) an intra-articular injection of bupivacaine or placebo (sodium chloride 0.9%) into the index knee. Assessments will be repeated post intra-articular injection apart from the MRI scan of the knee. Our aim is to provide proof of concept and descriptive statistics to power a future mechanistic trial. ETHICS AND DISSEMINATION: Ethical approval was obtained from the Health Research Authority (HRA) (REC: 20/EM/0287). Results will be disseminated via peer-reviewed journals and scientific conferences. The results will also be shared with lay audiences through relevant channels, such as Pain Centre Versus Arthritis website and patient advocacy groups. TRIAL REGISTRATION NUMBER: NCT05561010.

Prevalence of and factors associated with osteoarthritis and pain in retired Olympians compared with the general population: part 2 - the spine and upper limb.

OBJECTIVES: (1) To determine the prevalence of spine and upper limb osteoarthritis (OA) and pain in retired Olympians; (2) identify risk factors associated with their occurrence and (3) compare with a sample of the general population. METHODS: 3357 retired Olympians (44.7 years) and 1735 general population controls (40.5 years) completed a cross-sectional survey. The survey captured demographics, general health, self-reported physician-diagnosed OA, current joint/region pain and significant injury (lasting ≥1 month). Adjusted ORs (aORs) compared retired Olympians and the general population. RESULTS: Overall, 40% of retired Olympians reported experiencing current joint pain. The prevalence of lumbar spine pain was 19.3% and shoulder pain 7.4%, with lumbar spine and shoulder OA 5.7% and 2.4%, respectively. Injury was associated with increased odds (aOR, 95% CI) of OA and pain at the lumbar spine (OA=5.59, 4.01 to 7.78; pain=4.90, 3.97 to 6.05), cervical spine (OA=17.83, 1.02 to 31.14; pain=9.41, 6.32 to 14.01) and shoulder (OA=4.91, 3.03 to 7.96; pain=6.04, 4.55 to 8.03) in retired Olympians. While the odds of OA did not differ between Olympians and the general population, the odds of lumbar spine pain (1.44, 1.20 to 1.73), the odds of shoulder OA after prior shoulder injury (2.64, 1.01 to 6.90) and the odds of cervical spine OA in female Olympians (2.02, 1.06 to 3.87) were all higher for Olympians compared with controls. CONCLUSIONS: One in five retired Olympians reported experiencing current lumbar spine pain. Injury was associated with lumbar spine, cervical spine and shoulder OA and pain for Olympians. Although overall OA odds did not differ, after adjustment for recognised risk factors, Olympians were more likely to have lumbar spine pain and shoulder OA after shoulder injury, than the general population.

A Cross-Sectional Study of Retired Great British Olympians (Berlin 1936-Sochi 2014): Olympic Career Injuries, Joint Health in Later Life, and Reasons for Retirement from Olympic Sport.

BACKGROUND: The relationship between Olympic career sport injury and the long-term musculoskeletal health of the elite athlete remains unclear. This study describes the lifetime prevalence of medical attention injuries that occurred during training and/or competition as part of the athlete's Olympic career, reasons for retirement from Olympic sport, and the point prevalence of pain and osteoarthritis (OA) among retired Great Britain's (GB) Olympians. METHODS: This cross-sectional study involved distributing a questionnaire to retired GB Olympians who had competed at 36 Olympic Games between Berlin 1936 and Sochi 2014. The questionnaire captured Olympic career injury history (lasting ≥ 1 month), sport exposure, musculoskeletal pain (last 4 weeks), physician-diagnosed OA, and joint replacement. Injury prevalence was calculated for sports with a minimal of 15 respondents. Adjusted odds ratios (aOR) were estimated in logistic regression for pain, OA, and joint replacement. Models were adjusted for age, sex, BMI, and career duration. RESULTS: Six hundred fifty (57.8% male; 42.2% female) retired athletes representing 40 sports (29 summer; 11 winter), aged 60.5 years (range 23-97), completed the questionnaire. Overall, 721 injuries (368 athletes) were self-reported equating to a lifetime Olympic career injury prevalence of 56.6%. Injury prevalence was highest in field athletics (81.0%), gymnastics (75.0%), and track athletics (67.7%). Injuries most frequently occurred at the knee (19.0%), lower back (15.4%), and shoulder (11.5%). Of those injured, 19.5% retired from sport due to injury. Pain was most prevalent at the lumbar spine (32.8%), knee (25.3%), and hip (22.5%), and OA at the knee (13.4%), hip (10.4%), and lumbar spine (4.6%). Injury was associated with pain at the hip (aOR 4.88; 95% CI, 1.87-12.72, p = 0.001), knee (aOR 2.35; 95% CI, 1.45-3.81, p = 0.001), and lumbar spine (aOR 2.53; 95% CI, 1.63-3.92, p < 0.001); OA at the hip (aOR 5.97; 95% CI, 1.59-22.47, p = 0.008) and knee (aOR 3.91; 95% CI, 2.21-6.94, p < 0.001); and joint replacement at the hip (aOR 8.71; 95% CI, 2.13-35.63, p = 0.003) and knee (aOR 5.29; 95% CI, 2.39-11.74, p < 0.001). CONCLUSION: The lifetime prevalence of Olympic career injury was 56.6%, with those injured more likely to self-report current pain and/or OA at the hip, knee, and lumbar spine and joint replacement at the hip and knee.

Self-reported sports injuries and later-life health status in 3357 retired Olympians from 131 countries: a cross-sectional survey among those competing in the games between London 1948 and PyeongChang 2018.

OBJECTIVE: Describe the self-reported prevalence and nature of Olympic-career injury and general health and current residual symptoms in a self-selected sample of retired Olympians. METHODS: 3357 retired Olympians from 131 countries completed a cross-sectional online survey, distributed by direct email through World Olympians Association and National Olympian Associations databases. The survey captured Olympic sport exposure, significant training and competition injury history (lasting >1 month), general health (eg, depression) during the athlete's career, and current musculoskeletal pain and functional limitations. RESULTS: 55% were men (44% women, 1% unknown), representing 57 sports (42 Summer, 15 Winter), aged 44.7 years (range 16-97). A total of 3746 injuries were self-reported by 2116 Olympians. This equated, 63.0% (women 68.1%, men 59.2%) reporting at least one significant injury during their Olympic career. Injury prevalence was highest in handball (82.2%) and lowest in shooting (40.0%) for Summer Olympians; and highest in alpine skiing (82.4%) and lowest in biathlon (40.0%) for Winter Olympians. The knee was the most frequently injured anatomical region (20.6%, 120 median days severity), followed by the lumbar spine (13.1%, 100 days) and shoulder/clavicle (12.9%, 92 days). 6.6% of Olympians said they had experienced depression during their career. One-third of retired Olympians reported current pain (32.4%) and functional limitations (35.9%). CONCLUSIONS: Almost two-thirds of Olympians who completed the survey reported at least one Olympic-career significant injury. The knee, lumbar spine and shoulder/clavicle were the most commonly injured anatomical locations. One-third of this sample of Olympians attributed current pain and functional limitations to Olympic-career injury.

Factors associated with pain and osteoarthritis at the hip and knee in Great Britain's Olympians: a cross-sectional study.

BACKGROUND: Knowledge of the epidemiology and potentially modifiable factors associated with musculoskeletal disease is an important first step in injury prevention among elite athletes. AIM: This study investigated the prevalence and factors associated with pain and osteoarthritis (OA) at the hip and knee in Great Britain's (GB) Olympians aged 40 and older. METHODS: This is a cross-sectional study. A survey was distributed to 2742 GB Olympians living in 30 countries. Of the 714 (26.0%) who responded, 605 were eligible for analysis (ie, aged 40 and older). RESULTS: The prevalence of hip and knee pain was 22.4% and 26.1%, and of hip and knee OA was 11.1% and 14.2%, respectively. Using a multivariable model, injury was associated with OA at the hip (adjusted OR (aOR) 10.85; 95% CI 3.80 to 30.96) and knee (aOR 4.92; 95% CI 2.58 to 9.38), and pain at the hip (aOR 5.55; 95% CI 1.83 to 16.86) and knee (aOR 2.65; 95% CI 1.57 to 4.46). Widespread pain was associated with pain at the hip (aOR 7.63; 95% CI 1.84 to 31.72) and knee (aOR 4.77; 95% CI 1.58 to 14.41). Older age, obesity, knee malalignment, comorbidities, hypermobility and weight-bearing exercise were associated with hip and knee OA and/or pain. CONCLUSIONS: This study detected an association between several factors and hip and knee pain/OA in retired GB Olympic athletes. These associations require further substantiation in retired athletes from other National Olympic Committees, and through comparison with the general population. Longitudinal follow-up is needed to investigate the factors associated with the onset and progression of OA/pain, and to determine if modulation of such factors can reduce the prevalence of pain and OA in this population.

Development and validation of self-reported line drawings of the modified Beighton score for the assessment of generalised joint hypermobility.

BACKGROUND: The impracticalities and comparative expense of carrying out a clinical assessment is an obstacle in many large epidemiological studies. The purpose of this study was to develop and validate a series of electronic self-reported line drawing instruments based on the modified Beighton scoring system for the assessment of self-reported generalised joint hypermobility. METHODS: Five sets of line drawings were created to depict the 9-point Beighton score criteria. Each instrument consisted of an explanatory question whereby participants were asked to select the line drawing which best represented their joints. Fifty participants completed the self-report online instrument on two occasions, before attending a clinical assessment. A blinded expert clinical observer then assessed participants' on two occasions, using a standardised goniometry measurement protocol. Validity of the instrument was assessed by participant-observer agreement and reliability by participant repeatability and observer repeatability using unweighted Cohen's kappa (k). Validity and reliability were assessed for each item in the self-reported instrument separately, and for the sum of the total scores. An aggregate score for generalised joint hypermobility was determined based on a Beighton score of 4 or more out of 9. RESULTS: Observer-repeatability between the two clinical assessments demonstrated perfect agreement (k 1.00; 95% CI 1.00, 1.00). Self-reported participant-repeatability was lower but it was still excellent (k 0.91; 95% CI 0.74, 1.00). The participant-observer agreement was excellent (k 0.96; 95% CI 0.87, 1.00). Validity was excellent for the self-report instrument, with a good sensitivity of 0.87 (95% CI 0.81, 0.91) and excellent specificity of 0.99 (95% CI 0.98, 1.00). CONCLUSIONS: The self-reported instrument provides a valid and reliable assessment of the presence of generalised joint hypermobility and may have practical use in epidemiological studies.

The potential for nutritional components of food items used for enrichment of research animals to act as confounding variables in toxicology studies.

Produce and other non-certified foods may be provided to laboratory animals for enrichment, but this practice can generate scientific concerns, particularly if these food items contain nutrients that are pharmacologically active or affect animals' consumption of the basal diet. The author reviews information on potential for a number of nutritional components of food items to affect study data. On the basis of published effect levels, he proposes an upper limit for the consumption of each component in enrichment items relative to the amount present in a standard basal diet. He then assesses the amounts of these nutritional components in a broad range of food enrichment items and proposes a maximum serving size for each item for several common laboratory animals. Total caloric content and sugar content are the limiting components for many enrichment food items, but most items may be used as enrichment for laboratory animals without affecting study results, as long as the amounts of the items provided are managed.

The presence and management of contaminants in non-certified, agriculturally sourced food items used as enrichment for laboratory animals.

One enrichment strategy for laboratory animals is the provision of food variety and foraging opportunities. Fresh agricultural items, including produce or packaged human food items, provide variation in palatability, texture and complexity and can therefore be used as enrichment for lab animals. But concerns are often raised that these food items might sometimes carry contaminants that could affect research subjects and confound experimental results. The author discusses the potential for agriculturally sourced foods used as enrichment for lab animals to be contaminated with mycotoxins, microorganisms and pesticide residues and the effects these contaminants might have on lab animals. He also suggests strategies for reducing the risk of contamination.

Auditing laboratory rodent biosecurity programs.

A rodent biosecurity program that includes periodic evaluation of procedures used in an institution's vivarium can be used to ensure that best practices are in place to prevent a microbial pathogen outbreak. As a result of an ongoing comprehensive biosecurity review within their North American and European production facilities, the authors developed a novel biosecurity auditing process and worksheet that could be useful in other animal care and use operations. The authors encourage other institutions to consider initiating similar audits of their biosecurity programs to protect the health of their laboratory animals.

A novel rat model of hereditary hemochromatosis due to a mutation in transferrin receptor 2.

Sporadic iron overload in rats has been reported, but whether it is due to genetic or environmental causes is unknown. In the current study, phenotypic analysis of Hsd:HHCL Wistar rats revealed a low incidence of histologically detected liver iron overload. Here we characterized the pathophysiology of the iron overload and showed that the phenotype is heritable and due to a mutation in a single gene. We identified a single male rat among the 132 screened animals that exhibited predominantly periportal, hepatocellular iron accumulation. This rat expressed low RNA levels of the iron regulatory hormone hepcidin and low protein levels of transferrin receptor 2 (Tfr2), a membrane protein essential for hepcidin expression in humans and mice and mutated in forms of hereditary hemochromatosis. Sequencing of Tfr2 in the iron-overloaded rat revealed a novel Ala679Gly polymorphism in a highly conserved residue. Quantitative trait locus mapping indicated that this polymorphism correlated strongly with serum iron and transferrin saturations in male rats. Expression of the Gly679 variant in tissue culture cell lines revealed decreased steady-state levels of Tfr2. Characterization of iron metabolism in the progeny of polymorphic rats suggested that homozygosity for the Ala679Gly allele leads to a hemochromatosis phenotype. However, we currently cannot exclude the possibility that a polymorphism or mutation in the noncoding region of Tfr2 contributes to the iron-overload phenotype. Hsd:HHCL rats are the first genetic rat model of hereditary hemochromatosis and may prove useful for understanding the molecular mechanisms underlying the regulation of iron metabolism.

Effects of cage density, sanitation frequency, and bedding type on animal wellbeing and health and cage environment in mice and rats.

The objective of the current study was to evaluate the effects of cage density, sanitation frequency, and bedding type on animal growth and welfare. At weaning, Sprague-Dawley rats and C57BL/6 mice were allocated to treatment groups according to sex, bedding type (shredded aspen, cellulose, or a 50:50 mixture), and cage density and sanitation frequency (inhouse cage density standards and sanitation procedures measured against Guide recommendations) for an 8-wk period. Body weight, feed disappearance, cage ammonia, ATP concentrations, behavior, morbidity, and mortality were assessed weekly; fecal corticosterone, microbiology, and lung histopathology (rats only) were evaluated at the culmination of the trial. In both rats and mice, parameters indicative of animal health and welfare were not significantly affected by cage density and sanitation frequency or bedding type. Occasional effects of feed disappearance and cage ammonia concentrations due to density and sanitation guidelines were noted in rat cages, and bedding type affected cage ammonia and ATP concentrations. Periodic spikes of cage ammonia and ATP concentrations were recorded in mouse cages maintained according to inhouse compared with Guide standards and in cages containing aspen compared with cellulose or aspen-cellulose mixed bedding. Ongoing studies and historical data support the finding that deviations or exceptions from the cage density and sanitation frequency standards set forth in the Guide do not negatively affect animal health, welfare, or production parameters at our institution. These parameters appear to be credible measures of animal health and wellbeing and may be useful for evaluating performance standards for animal husbandry.

Influence of observational study design on the interpretation of cancer risk reduction by carotenoids.

Recently published literature has been reviewed to determine whether lycopene, beta-carotene, alpha-carotene, and beta-cryptoxanthin are associated with reductions in cancer risk and whether study findings differ by study design. A total of 57 publications meeting pre-defined inclusion and exclusion criteria were identified, with the majority (55) being observational studies. None of the intervention studies supported a significant reduction in cancer risk with carotenoid (beta-carotene) supplementation. The majority of observational studies did not support significant reductions in cancer risk with increased carotenoid dietary intakes/circulating levels. A larger percentage of case-control studies supported significant associations between increased dietary intakes/circulating levels of carotenoids relative to prospective (cohort and nested case-control) studies. Compared to prospective studies, case-control studies cannot be used to establish temporality and may be more susceptible to selection and recall biases. Thus, diet-disease relationships suggested by case-control studies should ideally be confirmed by additional evidence from prospective studies.

A simple method for assessing analgesic requirements and efficacy in rodents.

Evaluation of pain in the clinical setting is an ongoing challenge for veterinarians, researchers and IACUCs. Behavioral assessment, a common technique for evaluating pain, is subjective and difficult to translate into quantifiable data. The authors propose measuring changes in body weight, food consumption and water consumption as a simple and objective method for evaluating postsurgical pain and analgesic efficacy in rodents.

Refinement of the dosage and dosing schedule of ketoprofen for postoperative analgesia in Sprague-Dawley rats.

Though ketoprofen is commonly used in rodent surgical procedures, an optimal dosing regimen has not yet been established. The authors sought to refine ketoprofen dosage requirements in rats and to determine whether one or two doses were needed. In one experiment they compared the effects of one preoperative dose of ketoprofen with those of two perioperative doses (3 mg per kg body weight). In a second experiment they compared the effects of two different dosages of ketoprofen (3 or 5 mg per kg body weight). Results show that all regimens tested were similarly effective in curbing post-surgical weight loss and reduction in food and water consumption; therefore, a single dose of 3 mg per kg body weight was the most efficient.

Development of a percutaneous cerebrospinal fluid collection technique in F-344 rats and evaluation of cell counts and total protein concentrations.

A simple technique for cerebrospinal fluid (CSF) collection was developed in F-344 rats. Cell counts and total protein concentrations were evaluated to assess sample quality. While the 50 to 70 mu L samples of CSF collected on three different days showed a progressive decrease in the total erythrocyte and nucleated cell counts, no significant changes were observed in the total protein concentrations. Progressive decreases in the total erythrocyte count correlated positively with the decreases in volume of CSF collected. Our data suggest that collection of less than 50 mu L of CSF will give a better quality of CSF in F-344 rats. This is the first report of cellular and protein parameters in the CSF of F-344 rats.

Duration of clinical effects and absence of referred hyperalgesia after femoral vein cannulation in rats.

The goal of this study was to assess the duration of pain-related clinical effects and referred hyperalgesia after surgery in rats. Isoflurane anesthesia with or without femoral vein cannulation was performed (n = 6 per group). Body weight and food and water consumption were monitored daily for 48 h, and tail-flick latency was measured twice daily for 24 h after surgery. Water consumption at 24 h after surgery was significantly decreased in the surgical group compared with baseline values and those of the anesthesia group. Body weight change and food consumption showed nonsignificant decreases compared with baseline in both groups 24 h after the procedure. There was a trend toward decreased food consumption after surgery compared with that for the anesthesia-alone group. Tail-flick latency was nonsignificantly decreased the afternoon after surgery compared with baseline values or that after anesthesia alone. Tail-flick latency was similar to baseline and between groups 24 h after surgery. All parameters were similar between groups and compared with baseline by 48 h after surgery. Our results show some changes in postsurgical pain-related parameters only during the initial 24-h period after femoral cannulation surgery, but only the change in water consumption was significant. Although this study involved only a small number of animals, our findings suggest that femoral vein cannulation produces a less painful stimulus than that seen in studies assessing these parameters after abdominal surgery. Hyperalgesia from a distant painful stimulus could not be measured in this model by using the tail-flick assay.

Duration of effects on clinical parameters and referred hyperalgesia in rats after abdominal surgery and multiple doses of analgesic.

This study evaluated the duration of clinical effects and referred hyperalgesia in rats (n = 10 per group) undergo ing abdominal surgery with analgesics (ketoprofen at 3 mg/kg and buprenorphine at 0.01 or 0.1 mg/kg) administered intramuscularly twice daily for 72 h beginning prior to surgery; no-surgery and no-analgesia control groups were included. Food and water consumption and body weight were monitored daily. As a measure of referred hyperalgesia, tail-flick latency was measured daily, before and 4 h after analgesia administration. Compared with those of the no-surgery controls, significant decreases in food consumption and body weight occurred 24 h after surgery without analgesics. There were nonsignificant reductions in these effects by analgesics, but the benefits were not significantly different than those of saline. These parameters continued to be decreased with variable significance in the buprenorphine groups at 48 and 72 h after surgery. In both buprenorphine-treated groups, water consumption was significantly increased at 24 h after surgery but not at 48 or 72 h. Tail-flick latency was not significantly different between the no-surgery and no-analgesia groups but was significantly increased 4 h after high-dose buprenorphine administration and declined nonsignificantly over time in the other groups. We conclude that painful effects from surgery are present primarily during the first 24 h after surgery. The analgesic regimens tested did not completely reduce these effects. Buprenorphine was associated with adverse effects for as long as 72 h after surgery. Referred hyperalgesia from this abdominal surgery could not be measured using the tail-flick assay.