Examining age differences in duration of wage replacement by injury characteristics.

BACKGROUND: One explanation for why older age is associated with greater duration of wage replacement following a work-related injury may be that older workers sustain more severe injuries and different types of injury compared with their younger counterparts. AIMS: To examine the role of injury-related characteristics in explaining the impact of age on wage replacement duration, and whether the relationship between age and wage replacement duration is consistent across injury types and levels of severity. METHODS: A secondary analysis of workers' compensation claims in the Australian state of Victoria. In Victoria, only injuries which have accumulated >10 days of wage replacement, or have health care expenditures above a financial threshold, are eligible for compensation. Nested regression models were used to examine the relative contribution of injury-related characteristics to age differences in wage replacement duration. RESULTS: Older age was associated with greater days of wage replacement among men and women, even after adjusting for injury characteristics. Adjustment for differences in injury types and compensation reporting practices resulted in moderate attenuation of the age-duration relationship among men and small attenuation among women. The age-duration relationship was consistent across injury types/severity. CONCLUSIONS: The relationship between older age and greater duration of wage replacement is ubiquitous across injuries of different types and severity. Future research is required to understand better why older age is consistently associated with worse compensation outcomes following work-related injury.

Age, occupational demands and the risk of serious work injury.

BACKGROUND: Interest in the relationship between age and serious work injury is increasing, given the ageing of the workforce in many industrialized economies. AIMS: To examine if the relationship between age and risk of serious musculoskeletal injury differs when the physical demands of work are higher from those when they are lower. METHODS: A secondary analysis of workers' compensation claims in the State of Victoria, Australia, combined with estimates of the insured labour force. We focused on musculoskeletal claims, which required 10 days of absence or health care expenditures beyond a pecuniary threshold. Regression models examined the relationship between age and claim-risk across workers with different occupational demands, as well as the relationship between occupational demands and musculoskeletal claim-risk across different age groups. RESULTS: Older age and greater physical demands at work were associated with an increased risk of musculoskeletal claims. In models stratified by occupational demands, we observed the relationship between age and claim-risk was steeper when occupational demands were higher. We also observed that the relationship between occupational demands and risk of work injury claim peaked among workers aged 25-44, attenuating among those aged 45 and older. CONCLUSIONS: This study's results suggest that although older workers and occupations with higher demands should be the targets of primary preventive efforts related to serious musculoskeletal injuries, there may also be gains in targeting middle-aged workers in the most physically demanding occupations.

The effect of age and sex on peak oxygen uptake during upper and lower body exercise: A systematic review.

BACKGROUND: Large scale population norms for peak oxygen uptake (VO2peak) during cycle ergometry (CE) have been published for men and women across a wide range of ages. Although upper body functional capacity has an important role in activities of daily living far less is known regarding the effect of age and sex on upper body functional capacity (i.e. arm crank ergometry; ACE). The aim of this review was to determine the effect of age and sex on VO2peak obtained during ACE and CE in the same participants. METHOD: The review was pre-registered with PROSEPERO (Ref: CRD42022349566). A database search using Academic Search Complete including CINAHL complete, CINHAL Ultimate, Medline, PubMed, SPORTDiscus was undertaken. RESULTS: The initial search yielded 460 articles which was reduced to 243 articles following removal of duplicates. Twenty-five articles were subsequently excluded based on title resulting in 218 articles considered for retrieval. Following review of the abstracts, 78 further articles were excluded leaving 140 to be assessed for eligibility. Eighty-five articles were subsequently excluded, resulting in 55 articles being included. The decrease in VO2peak with age during CE was consistent with previous studies. Decreases in VO2peak during ACE with age, although paralleling those of CE, appeared to be of greater functional importance. When changes in VO2peak were considered below the age of 50 years little change was observed for absolute VO2peak during ACE and CE. In contrast, relative VO2peak demonstrated decreases in VO2peak for both ACE and CE likely reflecting increases in body mass and body fat percentage with age. After 50 years of age absolute and relative VO2peak demonstrated more similar and subtle responses. Heterogeneity across studies for both absolute and relative VO2peak between ACE and CE was large. Although strict inclusion criteria were applied, the inter-individual variation in sample populations was likely the main source of heterogeneity. There was a considerable lack data sets available for ages above 40 years of age. CONCLUSIONS: These responses suggest that upper body VO2peak decreases in line with that of the lower body but, due to the lower peak values achieved during ACE, decreases in VO2peak may have more profound functional impact compared to that for the lower body. Using absolute and relative measures of VO2peak results in different age-related profiles when considered below 50 years of age. To further our understanding of whole body ageing more data is required for participants in mid and later life. The association between VO2peak and underlying physiological factors with age needs to be studied further, particularly in conjunction with activities of daily living and independent living.

No effect of intravenous Actovegin® on peak aerobic capacity.

There is much speculation that Actovegin® is ergogenic, but no scientific work has been published in this field. 8 participants [mean(± SD) age, height and mass of 24 (7) years, 1.76 (0.07) m and 80.1 (9.1) kg, respectively] completed 3 exhaustive arm crank ergometry tests. Following Baseline testing 2 further tests were performed 2 h following the injection of either 40 ml of Actovegin® or a saline Placebo. Peak power (Wpeak), peak physiological responses, concentrations of blood glucose and lactate, exercise efficiency (%), VO2 gain (ml·W-1), and the respiratory compensation point (RCP) were determined. Repeated measures ANOVA tests were used to analyse data with significance accepted at p≤0.05. Values of mean (±90% CI) bias were calculated to further explore quantitative differences between trials. Strong trends for variations in Wpeak (p=0.054) and RCP (p=0.054) were evident; likely meaningful effects existed between the Baseline and both injection trials, but only a trivial effect was noted between Placebo and Actovegin® (bias: Wpeak 0.8±3.2 and RCP; 2.5±4.7 W). Concentrations of blood lactate and glucose changed across time, but did not differ between the 3 trials. Our data suggests the Actovegin® is not ergogenic and did not influence functional capacity in the context of the exhaustive, upper-body test employed.

The psychosocial work environment and incident diabetes in Ontario, Canada.

BACKGROUND: Relatively few longitudinal studies have explored the relationship between psychosocial work conditions and diabetes incidence. Given the increasing global burden of diabetes this is an important area for public health research. AIMS: To examine the relationships between dimensions of the psychosocial work environment on the subsequent incidence of diabetes among men and women in Ontario, Canada over a 9 year period. METHODS: We used data from Ontario respondents (35 to 60 years of age) to the 2000-01 Canadian Community Health Survey linked to the Ontario Health Insurance Plan database for physician services and the Canadian Institute for Health Information Discharge Abstract Database for hospital admissions. Our sample of actively employed labour market participants with no previous diagnoses for diabetes was followed for a 9 year period to ascertain incident diabetes. RESULTS: There were 7443 participants. Low levels of job control were associated with an increased risk of diabetes among women, but not among men. Counter to our hypotheses high levels of social support were also associated with increased diabetes risk among women, but not among men. No relationship was found between any psychosocial work measure and risk of diabetes among men. CONCLUSIONS: Given the increasing prevalence of diabetes worldwide, job control could potentially be an import ant modifiable risk factor to reduce the incidence of diabetes among female, but not among male, workers. More research is needed to understand the pathways through which low social support may protect against the development of diabetes.

Exploring the genetics underpinning dynamic laryngeal collapse associated with poll flexion in Norwegian-Swedish Coldblooded Trotter racehorses.

BACKGROUND: Dynamic laryngeal collapse (DLC) associated with poll flexion is the most common disorder of the upper respiratory tract (URT) in the Norwegian-Swedish Coldblooded Trotter (NSCT). The disorder, which has also been diagnosed in other breeds of trotters and gaited horses, appears to be related to anatomic phenotypes and only occurs during poll flexion when the horse is exercised 'on the bit'. OBJECTIVES: Identify genomic regions associated with DLC in the NSCT by combining a rigorous phenotyping protocol with genomic data from a high-density equine genotyping array. STUDY DESIGN: Prospective case/control study. METHODS: High-speed treadmill endoscopy was used to phenotype horses (n = 61) for DLC, distinguishing between cases and controls. Genome-wide association (GWA) analysis of DLC status was then performed using a principal component approach (PCA) with haplotype analyses subsequently performed for regions containing single-nucleotide polymorphisms (SNPs) above the suggestive genome-wide significance (GWS) threshold (P<1.0 × 10-5 ). RESULTS: One region containing 10 SNPs (Equus caballus chromosome [ECA] 7: 89,601,935-94,647,192) was above the suggestive GWS threshold. Two inferred haplotypes in this region demonstrated significant differences (P<0.001) between cases and controls, with the most frequent haplotype resulting in a significantly increased risk of DLC. MAIN LIMITATIONS: Small sample size as a result of stringent phenotyping protocols. CONCLUSIONS: The current study highlights a candidate genomic region on ECA7 as potentially important with regard to the manifestation of DLC. Further exploration of this region and the genes included within it will bring veterinarians and researchers closer to fully understanding the biological mechanisms underlying DLC in horses.

Gastrointestinal hormone actions in the central regulation of energy metabolism: potential sensory roles for the circumventricular organs.

A variety of circulating signals provide essential information to the central nervous system (CNS) regarding nutritional status. The gastrointestinal system produces many such molecules that are now known to have profound effects on feeding behavior and the control of metabolism as a consequence of their ability to regulate the neural circuitry involved in metabolic homeostasis. Although many of these substances have been suggested to directly access such brain centers, their lipophobic characteristics suggest that alternative mechanisms should be considered. In this paper, we consider one such alternative, namely, that a specialized group of CNS structures collectively known as the sensory circumventricular organs (CVOs), which are not protected by the normal blood-brain barrier, may play important roles in such blood to brain communications. Specifically, we review a developing literature that shows receptors for, and functional actions of, gastrointestinal hormones such as amylin, cholecystokinin, ghrelin and peptide YY in the area postrema and subfornical organ. Collectively, these observations suggest potentially significant roles for the sensory CVOs in the regulation of energy balance.

Comparing the risk of work-related injuries between immigrants to Canada and Canadian-born labour market participants.

OBJECTIVES: To examine the burden of work-related injuries among immigrants to Canada compared to Canadian-born labour force participants. METHODS: Using data from the 2003 and 2005 Canadian Community Health Surveys (n = 99,115), two nationally representative population samples, we examined the risk of self-reported, activity limiting work-related injuries among immigrants with varying time periods since arrival in Canada. Models were adjusted for hours of work in the last 12 months as well as various demographic and work-related variables. RESULTS: Immigrant men in their first 5 years in Canada reported lower rates of activity limiting injuries compared to Canadian-born respondents. Surprisingly, the percentage of injuries that required medical attention was much higher among recent immigrants compared to Canadian-born respondents, resulting in an increased risk of activity limiting injuries requiring medical attention among immigrant men compared to Canadian-born labour force participants. No excess risk was found among female immigrants compared to Canadian-born female labour market participants. CONCLUSIONS: Immigrant men in their first 5 years in Canada are at increased risk of work-related injuries that require medical attention. A similar risk is not present among immigrant women. Further, given differences in the number of activity limiting injuries requiring medical attention across immigrant groups, we believe this excess risk among immigrant men may be underestimated in the current data source. Future research should attempt to fully capture the barriers faced by immigrants in obtaining safe employment, the number of injuries that are sustained by immigrants while working, and the consequences of these injuries.

Differential risk of employment in more physically demanding jobs among a recent cohort of immigrants to Canada.

OBJECTIVE: To examine the proportion of a recent cohort of immigrants to Canada who were working in jobs that were more physically demanding than those in which they worked before migration to Canada. DESIGN: Longitudinal cohort of immigrants to Canada with occupational position measured before and 2 and 4 years after arrival in Canada. SUBJECTS: Respondents to Statistics Canada's Longitudinal Survey of Immigrants to Canada (LSIC). The LSIC surveyed a representative sample of immigrants, aged 15 and older, who arrived in Canada between November 2000 and December 2001. For the purpose of this study, the sample was restricted to respondents who had worked before immigrating and were working when re-interviewed 2 (n = 4331) or 4 (n = 4238) years after arrival in Canada. MAIN OUTCOME: Employment in an occupation with higher physical demands than that employed in before arrival in Canada. RESULTS: Respondents with less proficiency at speaking English and family class or refugee applicants were the most likely to be employed in occupations with higher physical demands both 2 and 4 years after arrival in Canada. CONCLUSIONS: Employment in a more physically demanding occupation may pose particular risks of workplace injury. In this sample of immigrants to Canada, respondents with poorer English skills and refugees (factors that may increase this risk) were more likely to be employed in more physically demanding occupations. Greater attention to the prevention of workplace injuries among particular groups of new immigrants to Canada is required.

Comparison of two regimens for the treatment of meningoencephalomyelitis of unknown etiology.

BACKGROUND: The optimal treatment for meningoencephalomyelitis of unknown etiology (MUE) remains unknown, despite the widespread use of a variety of immunosuppressive drugs. OBJECTIVE/HYPOTHESIS: To compare the efficacy of prednisolone combined with either vincristine and cyclophosphamide (COP group; n= 10) or with cytosine arabinoside (AraC group; n= 9). ANIMALS: Nineteen dogs with neurological deficits, neuroimaging, and cerebrospinal fluid abnormalities consistent with a diagnosis of MUE. METHODS: Prospective, blinded, and randomized clinical trial. Dogs fulfilling the inclusion criteria were randomly allocated to receive 1 drug regimen. RESULTS: Four of 10 dogs in the COP group and 5/9 in the AraC group survived > 12 months but neither the survival time nor the time-to-treatment failure differed between the 2 groups. Treatment with COP resulted in an unacceptable incidence of adverse effects. CONCLUSIONS: The adverse effects of COP make it an unsuitable treatment for MUE. Although survival of animals treated with AraC was broadly similar to that reported in recently published studies describing this treatment, it remains unclear whether it confers any benefit over using prednisolone alone.

Use of a lateral surgical approach to the femoral nerve in the management of two primary femoral nerve sheath tumours.

This case report describes the diagnosis and management of primary femoral nerve sheath tumours in two dogs. Both of the tumours were localised by electromyography (EMG) and magnetic resonance imaging (MRI), and were then surgically resected using a novel approach to the iliopsoas muscle via osteotomy of the ventral ilial wing. This approach should be considered when attempting surgical treatment of conditions affecting the iliopsoas muscle or the femoral nerve because it provides excellent exposure of these structures.

Thoracic stenosis causing lateral compression of the spinal cord in two immature Dogues de Bordeaux.

This case report describes a novel developmental vertebral malformation in two young Dogues de Bordeaux, which was diagnosed by magnetic resonance imaging. Both dogs were treated surgically with reasonable success.

Reflection across plant cell boundaries in confocal laser scanning microscopy.

The fluorescence patterns of proteins tagged with the green fluorescent protein (GFP) and its derivatives are routinely used in conjunction with confocal laser scanning microscopy to identify their sub-cellular localization in plant cells. GFP-tagged proteins localized to plasmodesmata, the intercellular junctions of plants, are often identified by single or paired punctate labelling across the cell wall. The observation of paired puncta, or 'doublets', across cell boundaries in tissues that have been transformed through biolistic bombardment is unexpected if there is no intercellular movement of the GFP-tagged protein, since bombardment usually leads to the transformation of single, isolated cells. We expressed a putative plasmodesmal protein tagged with GFP by bombarding Allium porrum epidermal cells and assessed the nature of the doublets observed at the cell boundaries. Doublets were formed when fluorescent spots were abutting a cell boundary and were only observable at certain focal planes. Fluorescence emitted from the half of a doublet lying outside the transformed cells was polarized. Optical simulations performed using finite-difference time-domain computations showed a dramatic distortion of the confocal microscope's point spread function when imaging voxels close to the plant cell wall due to refractive index differences between the wall and the cytosol. Consequently, axially and radially out-of-focus light could be detected. A model of this phenomenon suggests how a doublet may form when imaging only a single real fluorescent body in the vicinity of a plant cell wall using confocal microscopy. We suggest, therefore, that the appearance of doublets across cell boundaries is insufficient evidence for plasmodesmal localization due to the effects of the cell wall on the reflection and scattering of light.

Examining the relationships between job control and health status: a path analysis approach.

OBJECTIVE: To examine the pathways through which job control affects health status; to examine if the effects of job control on health status are attenuated by including other measures associated with lower socioeconomic status, and to examine if the relationship between job control and health status is consistent across socioeconomic status groups. DESIGN: A prospective observational cohort study over eight years (1994-2002). PARTICIPANTS: 4886 Respondents aged 25-60 years, who were non-self-employed labour force participants, working more than 20 hours per week, without physical or mental limitations restricting the type or amount of work they could do at baseline. After longitudinal attrition, the remaining study sample was 3411 (87% of the original study sample who did not die or become pregnant during the survey period). MAIN RESULTS: Low job control in 1994 was associated with worse than expected self-rated health in 2002, both directly and indirectly via a lower physical activity level in 1996. Adjustment for other factors associated with low socioeconomic status did not attenuate these relationships to a large extent. No differences were found in the effects of job control on physical activity or health status between socioeconomic groups (high and low education and high and low household income). CONCLUSIONS: The inclusion of other factors associated with lower socioeconomic status did not attenuate the direct and indirect effects of job control on health status. The finding that low job control is associated with lower physical activity levels deserves further investigation, given the increasing concern about rising levels of obesity in the developed world.

Findings on low-field cranial MR images in epileptic dogs that lack interictal neurological deficits.

Recurrent seizuring is a common neurological problem in dogs and can present diagnostic difficulties for the attending clinician. Associated interictal neurological deficits strongly suggest brain disease but the frequency of structural abnormalities in patients without such deficits is unknown. In this study the prevalence of clinically significant magnetic resonance imaging (MRI) abnormalities was determined in two groups of interictally normal dogs, those younger than 6 years and those older than 6 years of age. In the former group, only 1/46 dogs (2.2%) had significant MRI abnormalities, whereas in the latter group, 8/30 (26.7%) were abnormal. None of the dogs had an identifiable metabolic cause for the seizures. These findings suggest that the diagnostic yield of advanced neuroimaging techniques in young seizuring dogs without interictal neurological deficits is low, but reaffirms their value in similar older individuals.

Platelet C1- inhibitor. A secreted alpha-granule protein.

In order to characterize which proteins of the contact phase of coagulation interact with platelets, human platelets were studied immunochemically and functionally to determine if they contain C1- inhibitor. By means of monospecific antibody to C1- inhibitor, a competitive enzyme-linked immunosorbent assay (CELISA) was developed to measure directly platelet C1- inhibitor. With the CELISA, from 33 to 115 ng of C1- inhibitor antigen per 10(8) platelets from 15 normal donors was quantified in lysates of washed human platelets solubilized in nonionic detergent. The mean concentration in 10(8) platelets was 62 +/- 33 ng (SD). Plasma C1- inhibitor either in the platelet suspension medium or on the surface of the platelets could account for only from 6.5 to 16% of the total antigen measured in the solubilized platelets. Upon functional studies, platelets contained 84 +/- 36 ng (SD) of C1- inhibitor activity in 10(8) platelets. As assessed by the CELISA, platelet C1- inhibitor antigen was immunochemically identical to plasma and purified C1- inhibitor. In contrast, the mean concentration of platelet C1- inhibitor antigen in platelets from four patients with classical hereditary angioedema was 8.3 ng/10(8) platelets (range, 5.3 to 11.3 ng/10(8) platelets). 25 and 31% of the total platelet C1- inhibitor was secreted without cell lysis from normal platelets after exposure to collagen (20 micrograms/ml) and thrombin (1 U/ml), respectively, and this secretion was blocked by metabolic inhibitors. Platelet subcellular fractionation showed that platelet C1- inhibitor resided mostly in alpha-granules, similar to the location of platelet fibrinogen. Thus, human platelets contained C1- inhibitor, which became available by platelet secretion. The identification of platelet C1- inhibitor suggests that platelets may modulate the activation of the proteins of early blood coagulation and the classical complement pathways.

Cardiovascular actions of orexin-A in the rat subfornical organ.

Orexin-A is a neuropeptide, primarily produced in the lateral hypothalamic/perifornical hypothalamus. Orexin receptors and immunoreactive neuronal fibres are widely distributed throughout the brain, suggesting integrative neurotransmitter roles in a variety of physiological systems. Intracerebroventricular injections of orexin-A increase blood pressure and stimulate drinking, and the subfornical organ (SFO), a circumventricular structure implicated in autonomic control, is a potential site at which orexin may act to exert these effects. We have therefore used microinjection techniques to examine the effects of orexin-A administered directly into the SFO on blood pressure and heart rate in urethane anaesthetised male Sprague-Dawley rats. Orexin-A microinjection (50 fmol) into the SFO caused site-specific decreases in blood pressure (SFO: mean area under curve (AUC) = -681.7 +/- 46.8 mmHg*s, n = 22 versus non-SFO: 63.68 +/- 54.69 mmHg*s, n = 15, P < 0.001), and heart rate (SFO: mean AUC = -26.7 +/- 2.8 beats, n = 22, versus non-SFO: mean AUC = 1.62 +/- 2.1 beats, n = 15, P < 0.001). Vagotomy did not alter the hypotensive or bradycardic responses elicited by orexin-A microinjection. Prior alpha-adrenoceptor blockade with phenoxybenzamine (1 mg/kg, i.v.) masked the orexin-A induced blood pressure (mean AUC = -122.6 +/- 17.6 mmHg*s, n = 4, P < 0.01 paired t-test) and heart rate (mean AUC = -6.7 +/- 1.7 beats, n = 4, P < 0.05, paired test) response. The orexin-A induced heart rate response was attenuated when beta-adrenoceptors were blocked with propranolol (1 mg/kg, i.v.; mean AUC = 0.6 +/- 2.8 beats, n = 5, P < 0.01 paired t-test). These studies demonstrate that microinjection of orexin-A into the SFO causes site specific decreases in blood pressure and heart rate which is mediated by a reduction in sympathetic tone.

Brain abscess in a dog immunosuppressed using cyclosporin.

This report describes a dog that developed brain abscesses following prolonged immunosuppression with cyclosporin. Bacteria within the abscess were most likely Nocardia, an organism well recognised in immunosuppressed humans, and probably reached the brain through haematogenous spread from a more long-standing abscess in the mediastinum. Bacterial brain abscesses developing in this manner are very rare in dogs and this case highlights the wider range of possible diagnoses that need to be considered in immunosuppressed patients and the care with which potent drugs such as cyclosporin should be used.

Magnetic resonance imaging findings in epileptic cats with a normal interictal neurological examination: 188 cases.

Epilepsy is a common neurological condition in dogs and cats. Although an increased likelihood of significant brain lesions with age has been identified in neurologically normal dogs with epileptic seizures, the underlying aetiology of epileptic seizures in cats that present with normal physical and neurological examinations remains unknown. In this cross-sectional study, the authors examined MRI findings in a large population of cats with a normal interictal physical and neurological examination. They hypothesised that age would have an impact on the prevalence of detectable lesions. First, following the guidelines for dogs and in accordance with previous studies, the authors divided the cats into three age groups (aged one year or younger, between one and six, and older than six) and calculated the proportion of cats with a detectable lesion on MRI in these groups. In the first group, 3/32 cats (9.4 per cent) had significant MRI abnormalities that were all consistent with congenital malformation; in the second group, only 5/92 (5.4 per cent) MRI scans were abnormal and in the third group, 15/ 65 (23.1 per cent) cats showed abnormal findings that were predominantly lesions of neoplastic origin. Second, to investigate the impact of age further, data were investigated as a continuous variable using receiver operating characteristic analysis. This indicated an optimal cut-off age of five years, above which MRI abnormalities were more likely, with an increase in the odds of a significant structural lesion increasing by 14 per cent per year.

Long-distance movement of phosphate starvation-responsive microRNAs in Arabidopsis.

Plant microRNAs are small RNAs that are important for genetic regulation of processes such as plant development or environmental responses. Specific microRNAs accumulate in the phloem during phosphate starvation, and may act as long-distance signalling molecules. We performed quantitative PCR on Arabidopsis hypocotyl micrograft tissues of wild-type and hen1-6 mutants to assess the mobility of several phosphate starvation-responsive microRNA species. In addition to the previously confirmed mobile species miR399d, the corresponding microRNA* (miR399d*) was identified for the first time as mobile between shoots and roots. Translocation by phosphate-responsive microRNAs miR827 and miR2111a between shoots and roots during phosphate starvation was evident, while their respective microRNA*s were not mobile. The results suggest that long-distance mobility of microRNA species is selective and can occur without the corresponding duplex strand. Movement of miR399d* and root-localised accumulation of miR2111a* opens the potential for persisting microRNA*s to be mobile and functional in novel pathways during phosphate starvation responses.