Use of a Shear Reduction Surface for Prehospital Transport: A Randomized Crossover Study.

OBJECTIVE: To compare the effectiveness of an antishear mattress overlay (ASMO) with a standard ambulance stretcher surface in reducing pressure and shear and increasing patient comfort. METHODS: In this randomized, crossover design, adults in three body mass index categories served as their own controls. Pressure/shear sensors were applied to the sacrum, ischial tuberosity, and heel. The stretcher was placed in sequential 0°, 15°, and 30° head-of-bed elevations with and without an ASMO. The ambulance traveled a closed course, achieving 30 mph, with five stops at each head-of-bed elevation. Participants rated discomfort after each series of five runs. RESULTS: Thirty individuals participated. Each participant had 30 runs (15 with an ASMO, 15 without), for a total of 900 trial runs. The peak-to-peak shear difference between support surfaces was -0.03 N, indicating that after adjustment for elevation, sensor location, and body mass index, peak shear levels at baseline (starting pause) were 0.03 N lower for the ASMO than for the standard surface ( P = .02). The peak-to-peak pressure difference between surfaces was -0.16 mm Hg, indicating that prerun peak-to-peak pressure was 0.16 mm Hg lower with the ASMO versus standard surface ( P = .002). The heel received the most pressure and shear. Discomfort score distributions differed between surfaces at 0° ( P = .004) and 30° ( P = .01); the overall score across all elevations was significantly higher with the standard surface than with the ASMO ( P = .046). CONCLUSIONS: The ASMO reduced shear, pressure, and discomfort. During transport, the ambulance team should provide additional heel offloading.

Exploring Whether the Electronic Optimization of Routine Health Assessments Can Increase Testing for Sexually Transmitted Infections and Provider Acceptability at an Aboriginal Community Controlled Health Service: Mixed Methods Evaluation.

BACKGROUND: In the context of a syphilis outbreak in neighboring states, a multifaceted systems change to increase testing for sexually transmitted infections (STIs) among young Aboriginal people aged 15 to 29 years was implemented at an Aboriginal Community Controlled Health Service (ACCHS) in New South Wales, Australia. The components included electronic medical record prompts and automated pathology test sets to increase STI testing in annual routine health assessments, the credentialing of nurses and Aboriginal health practitioners to conduct STI tests independently, pathology request forms presigned by a physician, and improved data reporting. OBJECTIVE: We aimed to determine whether the systems change increased the integration of STI testing into routine health assessments by clinicians between April 2019 and March 2020, the inclusion of syphilis tests in STI testing, and STI testing uptake overall. We also explored the understandings of factors contributing to the acceptability and normalization of the systems change among staff. METHODS: We used a mixed methods design to evaluate the effectiveness and acceptability of the systems change implemented in 2019. We calculated the annual proportion of health assessments that included tests for chlamydia, gonorrhea, and syphilis, as well as an internal control (blood glucose level). We conducted an interrupted time series analysis of quarterly proportions 24 months before and 12 months after the systems change and in-depth semistructured interviews with ACCHS staff using normalization process theory. RESULTS: Among 2461 patients, the annual proportion of health assessments that included any STI test increased from 16% (38/237) in the first year of the study period to 42.9% (94/219) after the implementation of the systems change. There was an immediate and large increase when the systems change occurred (coefficient=0.22; P=.003) with no decline for 12 months thereafter. The increase was greater for male individuals, with no change for the internal control. Qualitative data indicated that nurse- and Aboriginal health practitioner-led testing and presigned pathology forms proved more difficult to normalize than electronic prompts and shortcuts. The interviews identified that staff understood the modifications to have encouraged cultural change around the role of sexual health care in routine practice. CONCLUSIONS: This study provides evidence for the first time that optimizing health assessments electronically is an effective and acceptable strategy to increase and sustain clinician integration and the completeness of STI testing among young Aboriginal people attending an ACCHS. Future strategies should focus on increasing the uptake of health assessments and promote whole-of-service engagement and accountability.

Integrating testing for sexually transmissible infections into annual health assessments for Aboriginal and Torres Strait Islander young people: a cross-sectional analysis.

BACKGROUND: In the context of an expanding syphilis epidemic, we assessed the integration of sexually transmissible infection (STI) testing within annual health assessments for Aboriginal and Torres Strait Islander young people aged 16-29years in Aboriginal Community Controlled Health Services between 2018 and 2020. METHODS: Using routinely collected electronic medical record data from a national sentinel surveillance system (ATLAS), we performed a cross-sectional analysis to calculate the proportion of assessments that integrated any or all of the tests for chlamydia, gonorrhoea, syphilis, and HIV. We used logistic regression to identify correlates of integration of any STI test. RESULTS: Of the 13 892 assessments, 23.8% (95% CI 23.1, 24.6) integrated a test for any STI and 11.5% (95% CI 10.9, 12.0) included all four STIs. Of assessments that included a chlamydia/gonorrhoea test, 66.9% concurrently included a syphilis test. Integration of any STI test was associated with patients aged 20-24years (OR 1.2, 95% CI 1.1-1.4) and 25-29years (OR 1.1, 95% CI 1.0-1.2) compared to 16-19years and patients residing in very remote (OR 4.2, 95% CI 3.7-4.8), remote (OR 2.4, 95% CI 2.1-2.8), and regional areas (OR 2.5, 95% CI 2.2-2.8) compared to metropolitan areas. There was no association with patient sex. CONCLUSIONS: Integration of STI testing into annual health assessments for Aboriginal and Torres Strait Islander young people was higher in remote areas where disease burden is greatest. Integration is similar in men and women, which contrasts with most studies that have found higher testing in women.

Infectious syphilis in women and heterosexual men in major Australian cities: sentinel surveillance data, 2011-2019.

OBJECTIVES: To examine changes in the positive infectious syphilis test rate among women and heterosexual men in major Australian cities, and rate differences by social, biomedical, and behavioural determinants of health. DESIGN, SETTING: Analysis of data extracted from de-identified patient records from 34 sexual health clinics participating in the Australian Collaboration for Coordinated Enhanced Sentinel Surveillance of Sexually Transmissible Infections and Blood Borne Viruses (ACCESS). PARTICIPANTS: First tests during calendar year for women and heterosexual men aged 15 years or more in major cities who attended ACCESS sexual health clinics during 2011-2019. MAIN OUTCOME MEASURES: Positive infectious syphilis test rate; change in annual positive test rate. RESULTS: 180 of 52 221 tested women (0.34%) and 239 of 36 341 heterosexual men (0.66%) were diagnosed with infectious syphilis. The positive test rate for women was 1.8 (95% confidence interval [CI], 0.9-3.2) per 1000 tests in 2011, 3.0 (95% CI, 2.0-4.2) per 1000 tests in 2019 (change per year: rate ratio [RR], 1.12; 95% CI, 1.01-1.25); for heterosexual men it was 6.1 (95% CI, 3.8-9.2) per 1000 tests in 2011 and 7.6 (95% CI, 5.6-10) per 1000 tests in 2019 (RR, 1.10; 95% CI, 1.03-1.17). In multivariable analyses, the positive test rate was higher for women (adjusted RR [aRR], 1.85; 95% CI, 1.34-2.55) and heterosexual men (aRR, 2.39; 95% CI, 1.53-3.74) in areas of greatest socio-economic disadvantage than for those in areas of least socio-economic disadvantage. It was also higher for Indigenous women (aRR, 2.39; 95% CI, 1.22-4.70) and for women who reported recent injection drug use (aRR, 4.87; 95% CI, 2.18-10.9) than for other women; it was lower for bisexual than heterosexual women (aRR, 0.48; 95% CI, 0.29-0.81) and for women who reported recent sex work (aRR, 0.35; 95% CI, 0.29-0.44). The positive test rate was higher for heterosexual men aged 40-49 years (aRR, 2.11; 95% CI, 1.42-3.12) or more than 50 years (aRR, 2.36; 95% CI, 1.53-3.65) than for those aged 15-29 years. CONCLUSION: The positive test rate among both urban women and heterosexual men tested was higher in 2019 than in 2011. People who attend reproductive health or alcohol and drug services should be routinely screened for syphilis.

Genetics of tibia bone properties of crossbred commercial laying hens in different housing systems.

Osteoporosis and bone fractures are a severe problem for the welfare of laying hens, with genetics and environment, such as housing system, each making substantial contributions to bone strength. In this work, we performed genetic analyses of bone strength, bone mineral density, and bone composition, as well as body weight, in 860 commercial crossbred laying hens from 2 different companies, kept in either furnished cages or floor pens. We compared bone traits between housing systems and crossbreds and performed a genome-wide association study of bone properties and body weight. As expected, the 2 housing systems produced a large difference in bone strength, with layers housed in floor pens having stronger bones. These differences were accompanied by differences in bone geometry, mineralization, and chemical composition. Genome scans either combining or independently analyzing the 2 housing systems revealed no genome-wide significant loci for bone breaking strength. We detected 3 loci for body weight that were shared between the housing systems on chromosomes 4, 6, and 27 (either genome-wide significant or suggestive) and these coincide with associations for bone length. In summary, we found substantial differences in bone strength, content, and composition between hens kept in floor pens and furnished cages that could be attributed to greater physical activity in pen housing. We found little evidence for large-effect loci for bone strength in commercial crossbred hens, consistent with a highly polygenic architecture for bone strength in the production environment. The lack of consistent genetic associations between housing systems in combination with the differences in bone phenotypes could be due to gene-by-environment interactions with housing system or a lack of power to detect shared associations for bone strength.

Integrating testing for sexually transmissible infections into routine primary care for Aboriginal young people: a strengths-based qualitative analysis.

OBJECTIVES: This paper examines factors that enabled successful integration of testing for sexually transmissible infections into routine care in Aboriginal Community Controlled Health Services. METHODS: This paper reports analysis of qualitative interview data recorded with 19 purposively sampled key informants in New South Wales, Australia, representing six Aboriginal Community Controlled Health Services and five government health bodies supporting those services. The analysis explicitly adopted a strengths-based approach. RESULTS: Participants reported a strong belief that routine screening overcomes shame and increases engagement with sexual health screening. Incorporating sexual health screening into general medical consultations increases the capture of asymptomatic cases. The Medicare Benefits Schedule 715 Adult Health Check was highlighted as an ideal lever for effective integration into routine care. CONCLUSION: Integration of testing for sexually transmissible infections into routine care is widely perceived as best practice by senior stakeholders in Aboriginal healthcare in NSW. Findings support continued work to optimise the MBS 715 as a lever to increase testing. IMPLICATIONS FOR PUBLIC HEALTH: Identifying accessible strategies to increase testing for sexually transmissible infections in Aboriginal Community Controlled Health Services can reduce disparities in notifications affecting Aboriginal young people.

No evidence that selection for egg production persistency causes loss of bone quality in laying hens.

BACKGROUND: The physiological adaptations that have evolved for egg laying make hens susceptible to bone fractures and keel bone damage. In modern laying hen breeds, longer periods of egg laying could result in a greater risk of poor bone quality, and selection for increased egg production has frequently been stated to be a cause. However, the existing literature does not support this hypothesis. To test the hypothesis that egg production is associated with quality, breaking strength and density of bone, genetic correlations between these traits were estimated in White Leghorn and Rhode Island Red breeds. Genetic correlations of cortical and medullary bone material chemical properties with bone quality were also estimated, in order to identify methods to improve bone quality with appropriately targeted measurement of key traits. RESULTS: Estimates of heritability for bone quality traits were moderate (0.19-0.59) for both White Leghorn and Rhode Island Red breeds, except for the keel bone trait, which had a heritability estimate equal to zero. There was no evidence for genetic or phenotypic relationships between post-peak egg production and bone quality. In the White Leghorn breed, the estimate of the genetic correlation between pre-peak production/age at first egg and bone quality was significant and negative (- 0.7 to - 0.4). Estimates of heritability of thermogravimetric measurements of tibial medullary bone mineralisation were significant (0.18-0.41), as were estimates of their genetic correlations with tibia breaking strength and density (0.6-0.9). CONCLUSIONS: The low genetic correlation of post-peak egg production with bone quality suggests that selection for increased persistency of egg production may not adversely affect bone quality. Onset of puberty and mineralisation of the medullary bone, which is a specialised adaptation for egg laying, were identified as important factors associated with the quality of the skeleton later during egg production. These are traits for which genetic, as well as environmental and management factors can positively impact the overall quality of the skeleton of laying hens.

Dissonances in communication with sexual health consumers in an inner-Sydney sexual health clinic in relation to health literacy: A mixed-methods study.

ISSUES ADDRESSED: This study examined the navigation of health care interactions by health consumers attending Sydney Sexual Health Centre (SSHC), an inner-city sexual health clinic in Sydney, Australia. We aimed to assess the accessibility and appropriateness of communications between SSHC and patients in the context of health literacy. METHODS: We conducted 20 semi-structured interviews with health consumers, assessed health literacy using the Short Health Literacy Assessment for English-Speaking Adults (SAHL-E) and conducted a focus group with clinical staff. RESULTS: We identified dissonances around assumed knowledge in communications between health professionals and health consumers, which were most apparent when lack of knowledge about sexual health, HIV and pre-exposure prophylaxis (PrEP) intersected with poor English fluency. SO WHAT?: This study suggests that existing models of access for HIV treatment and PrEP in Australia have been developed for high health literacy and may not support consumers who experience communication barriers due to low health literacy. The Australian Commission on Safety and Quality in Health Care recommends addressing health literacy systemically, including embedding assessment of health literacy into organisational systems and policies. We recommend developing tools to assess knowledge levels of consumers accessing sexual health services and incorporating health literacy into clinician training on working with patients from non-English-speaking backgrounds.

An eQTL in the cystathionine beta synthase gene is linked to osteoporosis in laying hens.

BACKGROUND: Skeletal damage is a challenge for laying hens because the physiological adaptations required for egg laying make them susceptible to osteoporosis. Previously, we showed that genetic factors explain 40% of the variation in end of lay bone quality and we detected a quantitative trait locus (QTL) of large effect on chicken chromosome 1. The aim of this study was to combine data from the commercial founder White Leghorn population and the F2 mapping population to fine-map this QTL and understand its function in terms of gene expression and physiology. RESULTS: Several single nucleotide polymorphisms on chromosome 1 between 104 and 110 Mb (galGal6) had highly significant associations with tibial breaking strength. The alternative genotypes of markers of large effect that flanked the region had tibial breaking strengths of 200.4 vs. 218.1 Newton (P < 0.002) and, in a subsequent founder generation, the higher breaking strength genotype was again associated with higher breaking strength. In a subsequent generation, cortical bone density and volume were increased in individuals with the better bone genotype but with significantly reduced medullary bone quality. The effects on cortical bone density were confirmed in a further generation and was accompanied by increased mineral maturity of the cortical bone as measured by infrared spectrometry and there was evidence of better collagen cross-linking in the cortical bone. Comparing the transcriptome of the tibia from individuals with good or poor bone quality genotypes indicated four differentially-expressed genes at the locus, one gene, cystathionine beta synthase (CBS), having a nine-fold higher expression in the genotype for low bone quality. The mechanism was cis-acting and although there was an amino-acid difference in the CBS protein between the genotypes, there was no difference in the activity of the enzyme. Plasma homocysteine concentration, the substrate of CBS, was higher in the poor bone quality genotype. CONCLUSIONS: Validated markers that predict bone strength have been defined for selective breeding and a gene was identified that may suggest alternative ways to improve bone health in addition to genetic selection. The identification of how genetic variants affect different aspects of bone turnover shows potential for translational medicine.

Short tandem repeats and methylation in the promoter region affect expression of cystathionine beta-synthase gene in the laying hen.

Homocysteine can be converted to cysteine via the transsulfuration pathway where cystathionine beta-synthase (CBS) is a rate-limiting enzyme. Homocysteine is thought to play a role in bone remodelling and strength. Previous results indicated that some of the difference in bone strength of end-of-lay hens may be associated with CBS expression level. To investigate if differences in the promoter region of the CBS gene might be responsible for observed differences in gene expression between CBS alleles post mortem- and in-vitro expression studies have been undertaken. Transfection of the DF-1 avian cell line with a series of deletion fragments of the 5' promoter, or constructs containing three CBS allele sequences, with a luciferase reporter revealed that a core region of -155 to +131 bp in the CBS promoter was essential for mRNA expression. We found that a variable number of short tandem repeats (7 nucleotide motif and 6 nucleotide repeats) in the core region of the promoter affecting the transcriptional activity and a strong effect for gene expression. However, methylation of the 6 nucleotide repeats varied between allelic variants and these maybe responsible for differences in promoter activity. Our findings indicated variable short tandem repeats and the differentially methylated sites in the promoter region may be responsible for CBS expression differences in the bone of laying hens.

A Retrospective, Descriptive Analysis of Hospital-acquired Deep Tissue Injuries.

Preventing, identifying, and treating deep tissue injury (DTI) remains a challenge. PURPOSE: The purpose of the current research was to describe the characteristics of DTIs and patient/care variables that may affect their development and outcomes at the time of hospital discharge. METHODS: A retrospective, descriptive, single-site cohort study of electronic medical records was conducted between October 1, 2010, and September 30, 2012, to identify common demographic, intrinsic (eg, mobility status, medical comorbidities, and incontinence), extrinsic (ie, surgical and procedural events, medical devices, head-of-bed elevation), and care and treatment factors related to outcomes of hospital-acquired DTIs; additional data points related to DTI development or descriptive of the sample (Braden Scale scores and subscale scores, hospital length of stay [LOS], intensive care unit [ICU] LOS, days from admission to DTI, time in the operating room, serum albumin levels, support surfaces/specialty beds, and DTI locations) also were retrieved. DTI healing outcomes, grouped by resolved, partial-thickness/stable, and full-thickness/unstageable, and 30 main patient/treatment variables were analyzed using Kruskal-Wallis, chi-squared, and Fischer exact tests. RESULTS: One hundred, seventy-nine (179) DTIs occurred in 141 adult patients (132 in men, 47 in women; mean patient age 64 [range 19-94]). Of those patients, 110 had a history of peripheral vascular disease and 122 had hypertension. Sixty-nine (69) DTIs were documented in patients who died within 1 year of occurrence. Most common DTI sites were the coccyx (47 [26%]) and heel (42 [23%]); 41 (22%) were device-related. Median hospital LOS was 23 (range 4-258) days and median ICU LOS was 12 (range 1-173) days; 40 DTIs were identified before surgery and 120 after a diagnostic or therapeutic procedure. Data for DTI outcome groups at hospital discharge included 28 resolved, 131 partial-thickness/stable, and 20 full-thickness/unstageable; factors significantly different between outcome groups included mechanical ventilation (15/42/12; P = .01), use of a feeding tube (15/46/12; P = .02), anemia (14/30/9; P = .005), history of cerebrovascular accident (12/27/7; P = .03), hospital LOS (67/18/37.5; P <.001), ICU LOS (23/10/12; P = .03), time-to-event (13.5/8/9; P = .001), vasopressor use after DTI (13/31/11; P = .003), low-air-loss surface (10/9/3; P = .005), and device-related (14/24/4; P = .002). CONCLUSION: DTI risk factors mirrored those of other PUs, but progression to full-thickness injury was not inevitable. Early and frequent assessment and timely intervention may help prevent DTI progression.

Genome-wide association study for bone strength in laying hens.

Bone fracture in egg laying hens is a growing welfare and economic concern in the industry. Although environmental conditions and management (especially nutrition) can exacerbate it, the primary cause of bone weakness and the resulting fractures is believed to have a genetic basis. To test this hypothesis, we performed a genome-wide association study to identify the loci associated with bone strength in laying hens. Genotype and phenotype data were obtained from 752 laying hens belonging to the same pure line population. These hens were genotyped for 580,961 SNPs, with 232,021 SNPs remaining after quality control. Each of the SNPs were tested for association with tibial breaking strength using the family-based score test for association. A total of 52 SNPs across chromosomes 1, 3, 8, and 16 were significantly associated with tibial breaking strength with the genome-wide significance threshold set as a corrected P value of 10e-5. Based on the local linkage disequilibrium around the significant SNPs, 5 distinct and novel QTLs were identified on chromosomes 1 (2 QTLs), 3 (1 QTL), 8 (1 QTL) and 16 (1 QTL). The strongest association was detected within the QTL region on chromosome 8, with the most significant SNP having a corrected P value of 4e-7. A number of candidate genes were identified within the QTL regions, including the BRD2 gene that is required for normal bone physiology. Bone-related pathways involving some of the genes were also identified including chloride channel activity, which regulates bone reabsorption, and intermediate filament organization, which plays a role in the regulation of bone mass. Our result supports previous studies that suggest that bone strength is highly regulated by genetics. It is therefore possible to reduce bone fractures in laying hens through genetic selection and ultimately improve hen welfare.

Combined negative pressure wound therapy and ultrasonic MIST therapy for open surgical wounds: a case series.

BACKGROUND: Surgical wounds are at increased risk of infection when left open to heal through secondary intention; they increase length of hospital stay, hospital costs, readmission rates, and patient morbidity. New technologies and methods of treating acute and chronic wounds are emerging. Two recent developments for the treatment of open wounds are noncontact low-frequency ultrasound (NCLFU) treatment and negative pressure wound therapy (NPWT). METHODS: This case series reports findings from 4 hospitalized patients with complex conditions who underwent colorectal surgery resulting in open abdominal wounds. The wounds were treated with NCLFU in combination with NPWT. Data were collected via retrospective review of medical records. RESULTS: After concurrent treatment with NPWT (range, 13-18 days) and NCLFU (range, 5-9 treatments), wound areas in these 4 cases were reduced by 4.5% to 37% and wound volume decreased by 17% to 62%. Granulation tissue increased in the open tissue areas in all patients. In addition, 3 of the cases received a mesh graft. CONCLUSIONS: Combination treatment with NPWT and NCLFU therapy with or without sharp debridement enhanced wound healing in the open abdominal wounds of these 4 patients.

The subunit structure and dynamics of the 20S proteasome in chicken skeletal muscle.

We have succeeded in purifying the 20S core proteasome particle from less than 1 g of skeletal muscle in a rapid process involving two chromatographic steps. The individual subunits were readily resolved by two-dimensional PAGE, and the identities of each of the 14 subunits were assigned by a combination of peptide mass fingerprinting and MS/MS/de novo sequencing. To assess the dynamics of proteasome biogenesis, chicks were fed a diet containing stable isotope-labeled valine, and the rate of incorporation of label into valine-containing peptides derived from each subunit was assessed by mass spectrometric analysis after two-dimensional separation. Peptides containing multiple valine residues from the 20S proteasome and other soluble muscle proteins were analyzed to yield the relative isotope abundance of the precursor pool, a piece of information that is essential for calculation of turnover parameters. The rates of synthesis of each subunit are rather similar, although there is evidence for high turnover subunits in both the alpha (nonproteolytic) and beta (proteolytic) rings. The variability in synthesis rate for the different subunits is consistent with a model in which some subunits are produced in excess, whereas others may be the rate-limiting factor in the concentration of 20S subunits in the cell. The ability to measure turnover rates of proteins on a proteome-wide scale in protein assemblies and in a complex organism provides a new dimension to the understanding of the dynamic proteome.

Proteome dynamics in complex organisms: using stable isotopes to monitor individual protein turnover rates.

The complete definition of changes in a proteome requires information about dynamics and specifically the rate at which the individual proteins are turned over intracellularly. Whilst this can be achieved in single-cell culture using stable isotope precursors, it is more challenging to develop methods for intact animals. In this study, we show how dietary administration of stable isotope-labelled amino acids can obtain information on the relative rates of synthesis and degradation of individual proteins in a proteome. The pattern of stable isotope-labelling in tryptic peptides can be deconstructed to yield a highly reliable measure of the isotope abundance of the precursor pool, a parameter that is often difficult to acquire. We demonstrate this approach using chickens fed a semisynthetic diet containing [(2)H(8)]valine at a calculated relative isotope abundance (RIA) of 0.5. When the labelling pattern of gel-resolved muscle proteins was analyzed, the intracellular precursor isotope abundance was 0.35, consistent with dilution of the amino acid precursor pool with unlabelled amino acids derived from degradation of pre-existing proteins. However, the RIA was stable over an extended labelling window, and permitted calculation of the rates of synthesis and degradation of individual proteins isolated by gel electrophoresis. For the first time, it is feasible to contemplate the analysis of turnover of individual proteins in intact animals.

Differences in metabolic parameters and gene expression related to osteochondrosis/osteoarthrosis in pigs fed 25-hydroxyvitamin D3.

Osteochondrosis/osteoarthrosis (OC/OA) are common terms for various joint pathologies that occur in pigs. Pathologies that may contribute to these disorders have been described, but the primary cause(s) remain unknown. We hypothesised that as OC has some similarities to dyschondroplasia, which involves a failure of growth plate chondrocytes to fully differentiate and hypertrophy, treatment with 25-hydroxyvitamin D3 (25-D) might reduce the incidence and/or severity of lesions in pigs, as it does in chickens with dyschondroplasia. Control pigs were fed a commercial diet ad libitum. In the treated group this diet was supplemented with 25-D at 0.1 mg/kg. Ten pigs from each of the control and treated groups were sampled at 7, 12, 16 and 21 weeks. Treatment with 25-D had no effect on the incidence or severity of OC/OA lesions. Cartilage dry weight, total collagen content and proteoglycan content, and plasma levels oftotal calcium, inorganic phosphorous, vitamin C, insuline-like growth factor-I, parathyroid hormone and tumour necrosis factor alpha were unaffected by treatment. In addition, none of these parameters were correlated with the incidence or severity of OC/OA lesions. The mRNA expression levels of 21 out of 23 genes assayed by RT-PCR were unaltered in articular cartilage from OA lesion samples as compared to normal articular cartilage. However, collagen type II was reduced and collagen type X increased in OA lesion and near lesion samples. These results suggest that OA in pigs may share some features of osteoarthritis in other mammalian species.