Physical and psychosocial work-related exposures and the occurrence of disorders of the shoulder: A systematic review update

This review is an update of a previous systematic review and assesses the evidence for the association of work-related physical and psychosocial risk factors and specific disorders of the shoulders. Medline, Embase, Web of Science Core Collection, Cochrane Central and PsycINFO were searched and study eligibility and risk of bias assessment was performed by two independent reviewers. A total of 14 new articles were added with the majority focusing on rotator cuff syndrome (RCS) with seven studies. Nine articles reported psychosocial exposures in addition to physical exposures. The strongest evidence was found for the association between elevation, repetition, force and vibration and the occurrence of SIS and tendinosis/tendonitis. Evidence also suggests that psychosocial exposures are associated with the occurrence of RCS and tendinosis/tendonitis. Other findings were inconsistent which prevents drawing strong conclusions.

Physical and psychosocial work-related exposures and the incidence of carpal tunnel syndrome: A systematic review of prospective studies

This systematic review summarizes the evidence on associations between physical and psychosocial work-related exposures and the development of carpal tunnel syndrome (CTS). Relevant databases were searched up to January 2020 for cohort studies reporting associations between work-related physical or psychosocial risk factors and the incidence of CTS. Two independent reviewers selected eligible studies, extracted relevant data, and assessed risk of bias (RoB). We identified fourteen articles for inclusion which reported data from nine cohort studies. Eight reported associations between physical exposure and the incidence of CTS and five reported associations between psychosocial exposures and the incidence of CTS. Quality items were generally rated as unclear or low RoB. Work-related physical exposure factors including high levels of repetition, velocity, and a combination of multiple physical exposures were associated with an increased risk of developing CTS. No other consistent associations were observed for physical or psychosocial exposures at work and CTS incidence.

Protocol for an observational study of working conditions and musculoskeletal health in Swedish online retail warehousing from the perspective of sex/gender and place of birth

European and International sustainable development agendas aim to reduce inequalities in working conditions and work-related health, yet disparate occupational health outcomes are evident between both men and women and domestic- and foreign-born workers. In Sweden, major growth in online retail warehousing has increased occupational opportunities for foreign-born workers. The rapid change has left research lagging on working conditions, i.e., employment conditions, facility design, work organisation, physical and psychosocial work environment conditions, and their effects on worker health. Further, no known studies have considered patterns of inequality related to these factors. The overall aim of this study is to describe working conditions and musculoskeletal health in online retail warehousing, determine the extent to which differences exist related to sex/gender and place of birth (as a proxy for race/ethnicity), and examine factors at the organisational and individual levels to understand why any differences exist. Three online retail warehouses, each employing 50-150 operations workers performing receiving, order picking, order packing and dispatching tasks will be recruited. Warehouses will, to the extent possible, differ in their extent of digital technology use. Employment conditions, facility design (including digital tool use), work organisation, physical and psychosocial work environment conditions and worker health will be assessed by survey, interview and technical measurements. Analysis of quantitative data stratified by sex and place of birth will consider the extent to which inequalities exist. Focus group interviews with operations employees and in-depth interviews with managers, union and health and safety representatives will be conducted to assess how employee working conditions and musculoskeletal health are related to inequality regimes of sex/gender and/or race/ethnicity in organisational processes and practices in online retail warehousing. The study is pre-registered with the Open Science Framework. This study will describe working conditions and health in online retail warehouse workers and consider the extent to which patterns of inequality exist based on sex/gender and place of birth.

Did the COVID-19 pandemic influence inequality in self-reported work environment conditions based on gender and place of birth? A study of a Swedish commercial laundromat

We evaluated differences in work environment conditions and health by gender and place of birth in a commercial laundromat prior to (baseline) and at the end of the first wave of the COVID-19 pandemic (follow-up). Using survey data, including dimensions from the Copenhagen Psychosocial Questionnaire, from forty-one workers, we assessed work environment conditions and health at baseline, follow-up and in change scores between baseline and follow-up. At baseline, men and women reported similar scores, while foreign-born (FB) workers reported better work environment conditions than Swedish-born (SB) workers. During the pandemic, conditions generally declined for all workers, but FB reported smaller declines than SB. A consistent inequality hierarchy across the 4 groups was not clear at baseline, follow-up or in change scores between time points. The study suggests potential cultural differences may exist in how work environment conditions are experienced. This should be considered in future studies and when managing future crises.

Exposure to hand-arm vibrations in the workplace and the occurrence of hand-arm vibration syndrome, Dupuytren's contracture, and hypothenar hammer syndrome: a systematic review and meta-analysis

This study provides an overview of the relationships between exposure to work-related hand-arm vibration and the occurrence of pre-defined disorders of the hands. We searched Medline, Embase, Web of Science, Cochrane Central, and PsycINFO for cross-sectional and longitudinal studies on the association between work-related vibration exposure and the occurrence of hand-arm vibration syndrome (including vibration-induced white finger), Dupuytren's contracture, or hypothenar hammer syndrome. We used a 16-item checklist for assessing the risk of bias. We present results narratively, and we conducted random effects meta-analyses if possible. We included 10 studies with more than 24,381 participants. Our results showed statistically significant associations between the exposure to hand-arm vibrations and the occurrence of the selected disorders, with pooled odds ratios ranging between 1.35 (95% CI: 1.28 to 2.80) and 3.43 (95% CI: 2.10 to 5.59). Considerable between-study heterogeneity was observed. Our analyses show that exposure to vibrating tools at work is associated with an increased risk for the occurrence of selected disorders of the hands. Due to the majority of studies being cross-sectional, no firm conclusion is possible regarding causal relationships between vibration exposure and disorder occurrence. Future research should specifically address whether reducing exposure to hand-held vibrating tools at work reduces the incidence of the disorders of the hands investigated in this systematic review.

Assessing the efficacy of a job rotation for improving occupational physical and psychosocial work environment, musculoskeletal health, social equality, production quality and resilience at a commercial laundromat: protocol for a longitudinal case study

INTRODUCTION

Job rotation is a work organisation strategy used to reduce work-related exposures and musculoskeletal complaints, yet evidence for the efficacy of the approach is weak. Mismatch between job rotation and company needs, lack of full implementation, lack of exposure variation in included tasks and failure to assess variation may underlie inconclusive research findings to date. The study aims to develop a job rotation with company stakeholders, perform a process evaluation of the implementation, and determine the extent to which the intervention improves the physical and psychosocial work environment, indicators of health, gender and social equality among workers and production quality and resilience.

METHODS AND ANALYSIS

Approximately 60 production workers at a Swedish commercial laundromat will be recruited. Physical and psychosocial work environment conditions, health, productivity and gender and social equality will be assessed pre and post intervention, using surveys, accelerometers, heart rate, electromyography and focus groups. A task-based exposure matrix will be constructed, and exposure variation estimated at the level of the individual worker pre and post intervention. An implementation process evaluation will be conducted. Job rotation efficacy will be assessed in terms of improvement in work environment conditions, health, gender and social inequality, and production quality and resilience. This study will provide novel information on the effects of the job rotation on physical and psychosocial work environment conditions, production quality and rate, health and gender and social inequality among blue-collar workers in a highly multicultural workplace.

ETHICS AND DISSEMINATION

The study received approval from the Swedish Ethical Review Authority (reference number 2019-00228). The results of the project will be shared directly with the employees, managers and union representatives from the participating company, other relevant labour market stakeholders and with researchers at national and international conferences and via scientific publication.

TRIAL REGISTRATION NUMBER

The study is preregistered with the Open Science Framework (https://osf.io/zmdc8/).

Physical and psychosocial work-related exposures and the occurrence of disorders of the elbow: A systematic review

This systematic review updates a previous systematic review on work-related physical and psychosocial risk factors for elbow disorders. Medline, Embase, Web of Science, Cochrane Central and PsycINFO were searched for studies on associations between work-related physical or psychosocial risk factors and the occurrence of elbow disorders. Two independent reviewers selected eligible studies and assessed risk of bias (RoB). Results of studies were synthesized narratively. We identified 17 new studies and lateral epicondylitis was the most studied disorder (13 studies). Five studies had a prospective cohort design, eight were cross-sectional and four were case-control. Only one study had no items rated as high RoB. Combined physical exposure indicators (e.g. physical exertion combined with elbow movement) were associated with the occurrence of lateral epicondylitis. No other consistent associations were observed for other physical and psychosocial exposures. These results prevent strong conclusions regarding associations between work-related exposures, and the occurrence of elbow disorders.

Surgery for subacromial impingement syndrome and occupational biomechanical risk factors in a 16-year prospective study among male construction workers

OBJECTIVE

The aim of this study was to assess the association between occupational biomechanical exposures and the occurrence of surgical treatment for subacromial impingement syndrome (SIS).

METHODS

A cohort of 220 295 male constructions workers who participated in a national occupational health surveillance program (1971-1993) were examined prospectively over a 16-year follow-up period (2001-2016) for surgically treated SIS. Worker job title, smoking status, height, weight, and age were registered on health examination. Job titles were mapped to 21 occupational groups based on tasks and training. A job exposure matrix (JEM) was developed with exposure estimates for each occupational group. Surgical cases were determined through linkage with the Swedish national in- and outpatient registers. Poisson regression was used to assess the relative risks (RR) for each biomechanical exposure.

RESULTS

The total incidence rate of surgically treated SIS over the 16-year observation period was 201.1 cases per 100 000 person-years. Increased risk was evident for workers exposed to upper-extremity loading (push/pull/lift) (RR 1.45-2.30), high hand grip force (RR 1.47-2.23), using handheld tools (RR 1.52-2.09), frequent work with hands above shoulders (RR 1.62-2.11), static work (RR 1.77-2.26), and hand-arm vibration (RR 1.78-2.13). There was an increased risk for SIS surgery for all occupational groups (construction trades) compared with white-collar workers (RR 1.56-2.61).

CONCLUSIONS

Occupational upper-extremity load and posture exposures were associated with increased risk for surgical treatment of SIS, which underlines the need for reducing workplace exposures and early symptom detection in highly exposed occupational groups.

Risk factors for surgically treated cervical spondylosis in male construction workers: a 20-year prospective study

BACKGROUND CONTEXT

Degenerative changes due to cervical spondylosis (CS) can detrimentally affect work ability and quality of life yet understanding of how physical exposure affects disease progression is limited.

PURPOSE

To assess the associations between occupational physical exposures and occurrence of surgically treated cervical spondylosis (ST-CS) and early exit from the labor market via disability pension.

STUDY DESIGN/SETTING

Prospective register study with 20 years follow-up period.

PATIENT SAMPLE

Swedish construction workers participating in a national health surveillance project conducted between 1971 and 1993.

OUTCOME MEASURES

Surgically treated cervical spondylosis (ST-CS) and early labor market exit at a minimum rate of 25% time on disability pension.

METHODS

Associations between occupational physical exposures (job exposure matrix) and subsequent ST-CS (National Hospital in-patient register) and early labor market exit via disability pension (Swedish Social Insurance Agency register) were assessed in a cohort of male construction workers (n=237,699).

RESULTS

A total of 1381 ST-CS cases were present and a 20 years incidence rate of 35.1 cases per 100,000 person years (95% confidence interval (CI) 33.2-36.9). Increased relative risk (RR) for ST-CS was found for workers exposed to non-neutral (RR 1.40, 95% CI 1.15-1.69), and awkward neck postures (1.52, 1.19-1.95), working with the hands above shoulder height (1.30, 1.06-1.60), and high upper extremity loading (1.35, 1.15-1.59). Increased risk was also present for workers who reported frequent neck (3.06, 2.18-4.30) and upper back (3.84, 2.57-5.73) pain in the 12 months prior to survey. Among workers with elevated arm exposure, higher risk was seen in those who also had more frequent neck pain. ST-CS cases took early retirement more often (41.3%) and at a younger age (53 years) than the total study cohort (14.8% and 56 years of age, respectively).

CONCLUSIONS

Occupational exposure to non-neutral neck postures, work with hands above shoulders and high loads born through the upper extremities increased the risk for ST-CS and early retirement due to disability. Decreasing postural and load exposure is salient for primary, secondary, and tertiary prevention of CS. Neck pain was shown to be a prognostic factor for ST-CS, which stresses the importance of acting early and taking preventative action to reduce workplace exposure, and the need for systematic medical check-ups within primary or occupational care to mitigate disease progression and early labour market exit due to disability.

Low mitochondrial genetic diversity in the Indian Ocean humpback dolphin Sousa plumbea in South African waters

The Indian Ocean humpback dolphin Sousa plumbea has been described as South Africa’s most endangered marine mammal due to its low abundance, reliance on coastal habitats with increasing anthropogenic threats and high rates of mortality from bycatch in bather protection nets (BPNs). Although the species has been well studied in South Africa, only a single study has examined its molecular ecology to date, and its population structure remains poorly understood. However, understanding population structure is vital for the conservation and management of a species. To address these research gaps for S. plumbea in South African waters, we analysed the mitochondrial D-loop of 157 museum skin and tooth samples collected between 1963 and 2017 from across the species’ geographic range in South Africa. Our data show that the humpback dolphin has extremely low mitochondrial diversity (haplotype diversity, HD = 0.47; nucleotide diversity, π = 0.2%) with only 3 haplotypes identified, which is comparable to the Critically Endangered Māui dolphin Cephalorhynchus hectori maui and the Critically Endangered Mekong population of Irrawaddy dolphin Orcaella brevirostris. Mitochondrial genetic diversity has not changed significantly in the last 50 yr, despite the high levels of bycatch in BPNs over this time period. Furthermore, we found no evidence of differentiation between dolphins from the KwaZulu-Natal Coast and the Cape South Coast (Western Cape and Eastern Cape). The extremely low mitochondrial diversity we found adds to the growing body of evidence that the humpback dolphin is becoming increasingly vulnerable and that urgent conservation efforts are required for the survival of the species.

South Georgia blue whales five decades after the end of whaling

Blue whales Balaenoptera musculus at South Georgia were heavily exploited during 20th century industrial whaling, to the point of local near-extirpation. Although legal whaling for blue whales ceased in the 1960s, and there were indications of blue whale recovery across the wider Southern Ocean area, blue whales were seldom seen in South Georgia waters in subsequent years. We collated 30 yr of data comprising opportunistic sightings, systematic visual and acoustic surveys and photo-identification to assess the current distribution of blue whales in the waters surrounding South Georgia. Over 34000 km of systematic survey data between 1998 and 2018 resulted in only a single blue whale sighting, although opportunistic sightings were reported over that time period. However, since 2018 there have been increases in both sightings of blue whales and detections of their vocalisations. A survey in 2020 comprising visual line transect surveys and directional frequency analysis and recording (DIFAR) sonobuoy deployments resulted in 58 blue whale sightings from 2430 km of visual effort, including the photo-identification of 23 individual blue whales. Blue whale vocalisations were detected on all 31 sonobuoys deployed (114 h). In total, 41 blue whales were photo-identified from South Georgia between 2011 and 2020, none of which matched the 517 whales in the current Antarctic catalogue. These recent data suggest that blue whales have started to return to South Georgia waters, but continued visual and acoustic surveys are required to monitor any future changes in their distribution and abundance.

Have whales returned to a historical hotspot of industrial whaling? The pattern of southern right whale Eubalaena australis recovery at South Georgia

Around 176500 whales were killed in the sub-Antarctic waters off South Georgia (South Atlantic) between 1904 and 1965. In recent decades, whales have once again become summer visitors, with the southern right whale (SRW) the most commonly reported species until 2011. Here, we assess the distribution, temporal pattern, health status and likely prey of SRWs in these waters, combining observations from a summertime vessel-based expedition to South Georgia, stable isotope data collected from SRWs and putative prey and sightings reports collated by the South Georgia Museum. The expedition used directional acoustics and visual surveys to localise whales and collected skin biopsies and photo-IDs. During 76 h of visual observation effort over 19 expedition days, SRWs were encountered 15 times (~31 individuals). Photo-IDs, combined with publicly contributed images from commercial vessels, were reconciled and quality-controlled to form a catalogue of 6 fully (i.e. both sides) identified SRWs and 26 SRWs identified by either left or right sides. No photo-ID matches were found with lower-latitude calving grounds, but 3 whales had gull lesions supporting a direct link with Península Valdés, Argentina. The isotopic position of SRWs in the South Georgia food web suggests feeding on a combination of copepod and krill species. Opportunistic reports of SRW sightings and associated group sizes remain steady over time, while humpback whales provide a strong contrast, with increased sighting rates and group sizes seen since 2013. These data suggest a plateau in SRWs and an increasing humpback whale presence in South Georgia waters following the cessation of whaling.

A comparison of baleen whale density estimates derived from overlapping satellite imagery and a shipborne survey

As whales recover from commercial exploitation, they are increasing in abundance in habitats that they have been absent from for decades. However, studying the recovery and habitat use patterns of whales, particularly in remote and inaccessible regions, frequently poses logistical and economic challenges. Here we trial a new approach for measuring whale density in a remote area, using Very-High-Resolution WorldView-3 satellite imagery. This approach has capacity to provide sightings data to complement and assist traditional sightings surveys. We compare at-sea whale density estimates to estimates derived from satellite imagery collected at a similar time, and use suction-cup archival logger data to make an adjustment for surface availability. We demonstrate that satellite imagery can provide useful data on whale occurrence and density. Densities, when unadjusted for surface availability are shown to be considerably lower than those estimated by the ship survey. However, adjusted for surface availability and weather conditions (0.13 whales per km², CV = 0.38), they fall within an order of magnitude of those derived by traditional line-transect estimates (0.33 whales per km², CV = 0.09). Satellite surveys represent an exciting development for high-resolution image-based cetacean observation at sea, particularly in inaccessible regions, presenting opportunities for ongoing and future research.

Consistent individual motor variability traits demonstrated by females performing a long-cycle assembly task under conditions differing in temporal organisation

Research suggests an association between motor variability (MV) during repetitive work and work-related musculoskeletal disorders (MSDs). However, whether MV is a consistent individual trait, even across working conditions or tasks, remains unknown. This study assessed whether individual MV traits were consistent during complex work performed under different temporal conditions. Fifteen women performed cyclic assembly under four conditions differing in pace and organisation (line-type, batch-type). MV of trapezius muscle activity and upper arm elevation was quantified and partitioned into variance components. For all MV metrics, a non-zero between-subjects variance was found, indicating consistent individual MV traits across conditions. Variance between subjects was higher for electromyography (EMG) MV metrics compared with kinematic metrics. Our results showed individuals exhibited consistent MV traits across working conditions differing in pace and production process. Further research is needed to understand whether MV is an individual predictive factor for MSD onset or progression.

Occupational biomechanical risk factors for radial nerve entrapment in a 13-year prospective study among male construction workers

Objectives

The aim was to assess the association between occupational biomechanical exposure and the occurrence of radial nerve entrapment (RNE) in construction workers over a 13-year follow-up period.

Methods

A cohort of 229 707 male construction workers who participated in a national occupational health surveillance programme (1971–1993) was examined prospectively (2001–2013) for RNE. Height, weight, age, smoking status and job title (construction trade) were obtained on health examination. RNE case status was defined by surgical release of RNE, with data from the Swedish national registry for out-patient surgery records. A job exposure matrix was developed, and biomechanical exposure estimates were assigned according to job title. Highly correlated exposures were summed into biomechanical exposure scores. Negative binomial models were used to estimate the relative risks (RR) (incidence rate ratios) of RNE surgical release for the biomechanical factors and exposure sum scores. Predicted incidence was assessed for each exposure score modelled as a continuous variable to assess exposure–response relationships.

Results

The total incidence rate of surgically treated RNE over the 13-year observation period was 3.53 cases per 100 000 person-years. There were 92 cases with occupational information. Increased risk for RNE was seen in workers with elevated hand-grip forces (RR=1.79, 95% CI 0.97 to 3.28) and exposure to hand-arm vibration (RR=1.47, 95% CI 1.08 to 2.00).

Conclusions

Occupational exposure to forceful handgrip work and vibration increased the risk for surgical treatment of RNE.

The cost of infection: Argulus foliaceus and its impact on the swimming performance of the three-spined stickleback (Gasterosteus aculeatus)

For fish, there can be multiple consequences of parasitic infections, including the physical impacts on swimming and the pathological costs of infection. This study used the three-spined stickleback (Gasterosteus aculeatus) and the ectoparasitic fish louse, Argulus foliaceus, to assess both physical (including form drag and mass) and pathological effects of infection. Both sustained (prolonged swimming within an open channel flume) and burst (C-start) swimming performance were measured on individual fish before (trials 1-2) and after infection (trials 3-5). Experimental infection occurred shortly before the third trial, when the physical impacts of infection could be separated from any subsequent pathology as transmission of adult parasites causes instantaneous drag effects prior to observable pathology. Despite the relatively large size of the parasite and corresponding increase in hydrodynamic drag for the host, there were no observable physical effects of infection on either sustained or burst host swimming. By contrast, parasite-induced pathology is the most probable explanation for reduced swimming performance across both tests. All sticklebacks displayed a preference for flow refugia, swimming in low-velocity regions of the flume, and this preference increased with both flow rate and infection time. This study suggests that even with large, physically demanding parasites their induced pathology is of greater concern than direct physical impact.

Occupational biomechanical risk factors for surgically treated ulnar nerve entrapment in a prospective study of male construction workers

Objectives The aim of this study was to determine the association between occupational biomechanical exposures and occurrence of surgically treated ulnar nerve entrapment (UNE). Methods A cohort of 229 689 male construction workers who participated in a national occupational health surveillance program (1971-1993) were examined prospectively over a 13-year case ascertainment period (2001-2013) for surgically treated UNE. Job title (construction trade), smoking status, height, weight and age were recorded on examination. Job titles were merged into occupational groups of workers performing similar work tasks and having similar training. Occupational biomechanical exposure estimates were assigned to each occupational group with a job exposure matrix (JEM) developed for the study. Negative binomial models were used to assess the relative risks for each biomechanical exposure and the sums of highly correlated biomechanical exposures. Surgical treatment of UNE was determined via a linkage with the Swedish Hospital Outpatient Surgery Register. Results There were 555 cases of surgically treated UNE within the cohort. Workers exposed to forceful hand-grip factors had a 1.4-fold higher relative risk (95% CI 1.18-1.63) of undergoing surgical treatment for UNE compared to unexposed workers. Occupational groups comprising workers exposed to forceful hand-grip work showed the highest risks for UNE and included concrete workers, floor layers, ground preparatory workers, rock blasters, and sheet-metal workers. Conclusion Forceful hand-grip work increases the risk for surgically treated ulnar nerve entrapment.

Observer performance in estimating upper arm elevation angles under ideal viewing conditions when assisted by posture matching software

Selecting a suitable body posture measurement method requires performance indices of candidate tools. Such data are lacking for observational assessments made at a high degree of resolution. The aim of this study was to determine the performance (bias and between- and within-observer variance) of novice observers estimating upper arm elevation postures assisted by posture matching software to the nearest degree from still images taken under ideal conditions. Estimates were minimally biased from true angles: the mean error across observers was less than 2°. Variance between observers was minimal. Considerable variance within observers, however, underlined the risk of relying on single observations. Observers were more proficient at estimating 0° and 90° postures, and less proficient at 60°. Thus, under ideal visual conditions observers, on average, proved proficient at high resolution posture estimates; further investigation is required to determine how non-optimal image conditions, as would be expected from occupational data, impact proficiency.

Effect of anti-gonadotropin-releasing factor vaccine and band castration on indicators of welfare in beef cattle

Angus crossbred bulls (n = 60; 257 ± 5.4 d of age; initial BW 358.8 ± 3.78 kg) were used to study the effect of a vaccine against gonadotropin-releasing factor (GnRF) and band castration on behavioral and physiological indicators of pain. Cattle were randomly assigned to 1 of 3 treatments: bulls, band-castrated calves without pain mitigation (castrated), and immune-vaccinated animals administered an anti-GnRF vaccine (vaccinated). All animals were fitted with a radio frequency ear tag so that individual animal feed intake and feeding behavior were recorded daily over the entire trial using an electronic feed bunk monitoring system. Two doses of anti-GnRF vaccine were administrated on d -35 and 0 and band castration was performed on d 0. Animal BW was recorded weekly starting on d -36 until d 56. Visual analog scores (VAS) were measured on d -36 -35, -1, and 0, and salivary cortisol concentration was measured at -30, 0, 30, 60, 120, and 270 min on d -35 and 0 after castration. Saliva and blood were obtained on d 1, 2, 5, and 7 and weekly until d 56 for determination of cortisol and complete blood cell count. Video data were collected for pain, sexual, and aggressive behavior daily the first week and once a week until d 56. Data were analyzed with a mixed-effect model with castration, time, and their interactions as main effects. Vaccinated calves had reduced ADG and intake (P < 0.05 and P < 0.001, respectively) during the first week after vaccination. Band-castrated calves had reduced ADG and intake (P < 0.001) until the end of the study. No differences in salivary cortisol and VAS were observed among groups at d -35 after the first vaccination and before band castration. However, on d 0, castrated cattle had greater cortisol concentrations and VAS (P < 0.05 and P < 0.01, respectively) than bulls and vaccinated animals. Complete blood cell count did not differ (P > 0.05) between treatments on d 0, 1, and 2. At d 56, vaccinated calves had greater (P < 0.05) final BW than band-castrated calves and both had less final BW than bulls. There was no indication that vaccination caused any physiological or behavioral changes indicative of pain. In contrast, band castration resulted in elevated cortisol scores and VAS indicative of a pain response and behavior related to pain (P < 0.001) until d 42 of the study. The present study demonstrates that anti-GnRF vaccine is a viable animal welfare-friendly alternative to traditional band castration in beef cattle under North American feedlot practices.

Immunology in wild nonmodel rodents: an ecological context for studies of health and disease

Transcriptomic methods are set to revolutionize the study of the immune system in naturally occurring nonmodel organisms. With this in mind, the present article focuses on ways in which the use of 'nonmodel' rodents (not the familiar laboratory species) can advance studies into the classical, but ever relevant, epidemiologic triad of immune defence, infectious disease and environment. For example, naturally occurring rodents are an interesting system in which to study the environmental stimuli that drive the development and homeostasis of the immune system and, by extension, to identify where these stimuli are altered in anthropogenic environments leading to the formation of immunopathological phenotypes. Measurement of immune expression may help define individual heterogeneity in infectious disease susceptibility and transmission and facilitate our understanding of infection dynamics and risk in the natural environment; furthermore, it may provide a means of surveillance that can filter individuals carrying previously unknown acute infections of potential ecological or zoonotic importance. Finally, the study of immunology in wild animals may reveal interactions within the immune system and between immunity and other organismal traits that are not observable under restricted laboratory conditions. Potentiating much of this is the possibility of combining gene expression profiles with analytical tools derived from ecology and systems biology to reverse engineer interaction networks between immune responses, other organismal traits and the environment (including symbiont exposures), revealing regulatory architecture. Such holistic studies promise to link ecology, epidemiology and immunology in natural systems in a unified approach that can illuminate important problems relevant to human health and animal welfare and production.

Is what you see what you get? Standard inclinometry of set upper arm elevation angles

Previous research suggests inclinometers (INC) underestimate upper arm elevation. This study was designed to quantify possible bias in occupationally relevant postures, and test whether INC performance could be improved using calibration. Participants were meticulously positioned in set arm flexion and abduction angles between 0° and 150°. Different subject-specific and group-level regression models comprising linear and quadratic components describing the relationship between set and INC-registered elevation were developed using subsets of data, and validated using additional data. INC measured arm elevation showed a downward bias, particularly above 60°. INC data adjusted using the regression models were superior to unadjusted data; a subject-specific, two-point calibration based on measurements at 0° and 90° gave results closest to the 'true' set angles. Thus, inclinometer measured arm elevation data required calibration to arrive at 'true' elevation angles. Calibration to a common measurement scale should be considered when comparing arm elevation data collected using different methods.

Comparison of insulin lispro protamine suspension versus insulin glargine once daily added to oral antihyperglycaemic medications and exenatide in type 2 diabetes: a prospective randomized open-label trial

AIMS

To compare efficacy and safety of two, once-daily basal insulin formulations [insulin lispro protamine suspension (ILPS) vs. insulin glargine (glargine)] added to oral antihyperglycaemic medications (OAMs) and exenatide BID in suboptimally controlled type 2 diabetes (T2D) patients.

METHODS

This 24-week, open-label, multicentre trial randomized patients to bedtime ILPS (n = 171) or glargine (n = 168). Non-inferiority of ILPS versus glargine was assessed by comparing the upper limit of 95% confidence intervals (CIs) for change in haemoglobin A1c (HbA1c) from baseline to week 24 (adjusted for baseline HbA1c) with non-inferiority margin 0.4%.

RESULTS

Non-inferiority of ILPS versus glargine was demonstrated: least-squares mean between-treatment difference (ILPS minus glargine) (95% CI) was 0.22% (0.06, 0.38). Mean HbA1c reduction was less for ILPS- versus glargine-treated patients (-1.16 ± 0.84 vs. -1.40 ± 0.97%, p = 0.008). Endpoint HbA1c < 7.0% was achieved by 53.7% (ILPS) and 61.7% (glargine) (p = NS). Overall hypoglycaemia rates (p = NS) and severe hypoglycaemia incidence (p = NS) were similar. Nocturnal hypoglycaemia rate was higher in patients treated with ILPS versus glargine (p = 0.004). Weight gain was similar between groups (ILPS: 0.27 ± 3.38 kg; glargine: 0.66 ± 3.93 kg, p = NS). Endpoint total insulin doses were lower in patients treated with ILPS versus glargine (0.30 ± 0.17 vs. 0.37 ± 0.17 IU/kg/day, p < 0.001).

CONCLUSIONS

ILPS was non-inferior to glargine for HbA1c change over 24 weeks, but was associated with less HbA1c reduction and more nocturnal hypoglycaemia. Treat-to-target basal insulin therapy improves glycaemic control and is associated with minimal weight gain when added to OAMs and exenatide BID for suboptimally controlled T2D.

Statistical performance of observational work sampling for assessment of categorical exposure variables: a simulation approach illustrated using PATH data

Objectives:

Observational work sampling is often used in occupational studies to assess categorical biomechanical exposures and occurrence of specific work tasks. The statistical performance of data obtained by work sampling is, however, not well understood, impeding informed measurement strategy design. The purpose of this study was to develop a procedure for assessing the statistical properties of work sampling strategies evaluating categorical exposure variables and to illustrate the usefulness of this procedure to examine bias and precision of exposure estimates from samples of different sizes.

Methods:

From a parent data set of observations on 10 construction workers performing a single operation, the probabilities were determined for each worker of performing four component tasks and working in four mutually exclusive trunk posture categories (neutral, mild flexion, severe flexion, twisted). Using these probabilities, 5000 simulated data sets were created via probability-based resampling for each of six sampling strategies, ranging from 300 to 4500 observations. For each strategy, mean exposure and exposure variability metrics were calculated at both the operation level and task level and for each metric, bias and precision were assessed across the 5000 simulations.

Results:

Estimates of exposure variability were substantially more uncertain at all sample sizes than estimates of mean exposures and task proportions. Estimates at small sample sizes were also biased. With only 600 samples, proportions of the different tasks and of working with a neutral trunk posture (the most common) were within 10% of the true target value in at least 80% of all the simulated data sets; rarer exposures required at least 1500 samples. For most task-level mean exposure variables and for all operation-level and task-level estimates of exposure variability, performance was low, even with 4500 samples. In general, the precision of mean exposure estimates did not depend on the exposure variability between workers.

Conclusions:

The suggested probability-based simulation approach proved to be versatile and generally suitable for assessing bias and precision of data collection strategies using work sampling to estimate categorical data. The approach can be used in both real and hypothetical scenarios, in ergonomics, as well as in other areas of occupational epidemiology and intervention research. The reported statistical properties associated with sample size are likely widely relevant to studies using work sampling to assess categorical variables.

Should we be more on the ball? The efficacy of accommodation training on lumbar spine posture, muscle activity, and perceived discomfort during stability ball sitting

OBJECTIVE

The aim of this study was to evaluate the efficacy of a 9-day accommodation protocol on reducing perceived discomfort while sitting on a stability ball (SB); trunk muscle activity levels and lumbar spinal postures were also considered.

BACKGROUND

Previous studies have compared SB sitting with office chair sitting with few observed differences in muscle activity or posture; however, greater discomfort during SB sitting has been reported. These findings may indicate an accommodation period is necessary to acclimate to SB sitting.

METHOD

For this study, 6 males and 6 females completed two separate, 2-hr sitting sessions on an SB. Half the participants completed a 9-day accommodation period between the visits, whereas the other half did not use an SB during the time. On both occasions, self-reported perceived discomfort ratings were collected along with erector spinae and abdominal muscle activity and lumbar spinal postures.

RESULTS

Discomfort ratings were reduced in female participants following the accommodation; no effects on muscle activation or lumbar spine postures were observed.

CONCLUSION

Accommodation training may reduce perceived low-back discomfort in females.Trunk muscle activity and lumbar spine postures during seated office work on an SB did not differ between groups; however, greater sample power was required to conclusively address these variables.

APPLICATION

Regarding whether to use an SB in place of a standard office chair, this study indicates that females electing to use an SB can decrease discomfort by following an accommodation protocol; no evidence was found to indicate that SB chair use will improve trunk strength or posture, even following an accommodation period.

Macroparasites at peripheral sites of infection are major and dynamic modifiers of systemic antimicrobial pattern recognition responses

Immune defences and the maintenance of immunological homeostasis in the face of pathogenic and commensal microbial exposures are channelled by innate antimicrobial pattern recognition receptors (PRRs) such as toll-like receptors (TLRs). Whilst PRR-mediated response programmes are the result of long-term host-pathogen or host-commensal co-evolutionary dynamics involving microbes, an additional possibility is that macroparasitic co-infections may be a significant modifier of such interactions. We demonstrate experimentally that macroparasites (the model gastrointestinal nematode, Heligmosomoides) at peripheral sites of infection cause substantial alteration of the expression and function of TLRs at a systemic level (in cultured splenocytes), predominantly up-regulating TLR2, TLR4 and TLR9-mediated cytokine responses at times of high standing worm burdens. We consistently observed such effects in BALB/c and C57BL/6 mice under single-pulse and trickle exposures to Heligmosomoides larvae and in SWR and CBA mice under single-pulse exposures. A complementary long-term survey of TLR2-mediated tumour necrosis factor-alpha responses in wild wood mice (Apodemus sylvaticus) was consistent with substantial effects of macroparasites under some environmental conditions. A general pattern, though, was for the associations of macroparasites with TLR function to be temporally dynamic and context-dependent: varying with different conditions of infection exposure in the field and laboratory and with host genetic strain in the laboratory. These results are compelling evidence that macroparasites are a major and dynamic modifier of systemic innate antimicrobial responsiveness in naturally occurring mammals and thus likely to be an important influence on the interaction between microbial exposures and the immune system.

Effects of feeding endophyte-infected (Acremonium coenophialum ) KY-31 fescue hay on the reproductive development of Holstein bulls

This study was designed to assess the effect of endophyte-infected (Acremonium coenophialum ) tall fescue (KY-31) on reproductive development in bulls. Eighteen Holstein bull calves (2 mo old) were randomly allocated to one of two dietary treatments consisting of 1) noninfected KY-31 fescue hay (NON) supplemented with grain (n=9) and 2) infected (67% infected by Acremonium coenophialum ) KY-31 fescue hay (INF) supplemented with grain (n=9). Both dietary treatments consisted of equal amounts of hay and grain. Data were collected every 14 d. Body weight, hip height and scrotal circumference did not differ (P>0.05) in the two treatments. Mean rectal temperatures also were not different in bulls (P = 0.12); however the infected bulls experienced higher rectal temperatures in all but four collection periods. Animals were sacrificed at 13 mo of age. Testicular weight and dimensions, epididymal weight and length as well as seminal vesicle weight were not different (P>0.05). Maturity of spermatozoa taken from each cauda epididymides was assessed by the incidence of cytoplasmic droplets and was not different (P>0.05) between treatments. Daily sperm production potential was not different (P>0.05) between treatments; however, large variations were noted among the infected bulls. Blood testosterone levels were not different (P=0.29) between the two dietary treatments, but were different over time (P<0.001) with NON and INF bulls having 2.14 +/- 0.21 and 2.41 +/- 0.22 ng/ml, respectively. Prolactin levels were different (P<0.02) between the NOn and INF bulls, 29.35 +/- 3.35 vs 18.31 +/- 3.39 ng/ml, respectively; and over time (P<0.001). The data generated in this study showed some important biological trends. Overall, the results indicate that endophyte infected KY-31 fescue hay fed to growing bulls did not appear to have severe detrimental effects on body growth or reproductive development. However, additional studies will be necessary to further delineate the patterns established in this study.

Immunocastration of Bos indicus x Brown Swiss bulls in feedlot with gonadotropin-releasing hormone vaccine Bopriva provides improved performance and meat quality

The objective of this study was to determine the effects of a GnRH vaccine on feedlot performance and meat quality in Bos indicus Zebu × Brown Swiss bulls. The study was a 2 × 2 factorial arrangement of treatments with 1,600 bulls allocated by BW into 4 groups of ≈ 400 animals. The GnRH vaccine (Bopriva) was injected on d 0 and 42, and anabolic implants given on d 0 (Component E-S) and d 84 (Synovex Choice). Group designations were: Con = placebo control; Imp = implants alone; Vac = GnRH vaccine alone; and Vac+Imp = GnRH vaccine together with implants. The second GnRH vaccination at d 42 resulted in elevated titers of IgG antibody and suppressed concentrations of testosterone in vaccinated groups (Vac and Vac+Imp) at d 56 (P < 0.001), with titers and suppressed testosterone persisting to d 147 (P < 0.001). Groups Vac and Vac+Imp had reduced testes weights at slaughter on d 147 (P < 0.001). Bulls in group Vac were not different in final BW, HCW, or ADG (d 42 to 147) relative to bulls in group Con. Bulls in group Vac+Imp had greater final BW than bulls in group Imp (P = 0.008) and greater BW than bulls in group Vac and group Con (P < 0.001). The HCW of Vac+Imp bulls was greater than the Vac or Con bulls (P < 0.001) but was not different to the Imp bulls (P = 0.294). Improved ADG was obtained by vaccination with the GnRH vaccine, in the presence of implants (group Vac+Imp compared with group Imp, P < 0.001) or absence of implants (group Vac compared with group Con, P = 0.028). Meat quality of bulls receiving the GnRH vaccine was improved irrespective of implant status, with a 1.6- to 2.6-fold increase in the proportion of bulls in groups Vac and Vac+Imp, respectively, grading as USDA Choice (P < 0.002) and with greater fat depth at the 12th rib (P < 0.001). Meat tenderness was improved in the vaccine groups (Vac and Vac+Imp) compared with groups Con and Imp (P < 0.004). Use of the GnRH vaccine Bopriva in Bos indicus × Brown Swiss bulls finishing in a feedlot under Mexican husbandry conditions can provide improved performance in combination with implants (increased BW and ADG) and improved meat quality, with or without implants, and in particular, better USDA carcass grading and loin fat cover.

Urinary chemokines CXCL9 and CXCL10 are noninvasive markers of renal allograft rejection and BK viral infection

Renal transplant recipients require periodic surveillance for immune-based complications such as rejection and infection. Noninvasive monitoring methods are preferred, particularly for children, for whom invasive testing is problematic. We performed a cross-sectional analysis of adult and pediatric transplant recipients to determine whether a urine-based chemokine assay could noninvasively identify patients with rejection among other common clinical diagnoses. Urine was collected from 110 adults and 46 children with defined clinical conditions: healthy volunteers, stable renal transplant recipients, and recipients with clinical or subclinical acute rejection (AR) or BK infection (BKI), calcineurin inhibitor (CNI) toxicity or interstitial fibrosis (IFTA). Urine was analyzed using a solid-phase bead-array assay for the interferon gamma-induced chemokines CXCL9 and CXCL10. We found that urine CXCL9 and CXCL10 were markedly elevated in adults and children experiencing either AR or BKI (p = 0.0002), but not in stable allograft recipients or recipients with CNI toxicity or IFTA. The sensitivity and specificity of these chemokine assays exceeded that of serum creatinine. Neither chemokine distinguished between AR and BKI. These data show that urine chemokine monitoring identifies patients with renal allograft inflammation. This assay may be useful for noninvasively distinguishing those allograft recipients requiring more intensive surveillance from those with benign clinical courses.

Influence of three principles of pacing on the temporal organisation of work during cyclic assembly and disassembly tasks

A study was conducted to investigate the influence of different approaches to arranging the pace and temporal organisation of repetitive assembly and disassembly tasks on both average performance and its variability and to compare assembly and disassembly times derived with psychophysical methods to a more traditional methods-time measurement (MTM) approach. The conditions studied were a traditional assembly line arrangement, where assemblies were started at a pace of 110 MTM (repeated on two occasions), a batch condition, where subjects were required to complete 36 assemblies within the total amount of time allowed at 110, MTM and a psychophysical condition, where subjects were allowed to choose their pace (repeated on two occasions). Overall, the results suggest that the mean time spent working in each cycle (the 'on-time') remained fairly constant across conditions, while the idle 'off-time' in between on-times was shorter and of less varied duration in the more autonomous batch and psychophysical conditions. During the second psychophysical (self-paced) condition, subjects completed a significantly higher number of assemblies than during the 110 MTM line condition. The higher pace was achieved through reduction in mean off-times and the potential implications for musculoskeletal risk are discussed. STATEMENT OF RELEVANCE: Higher levels of autonomy over work pace, which intuitively would be beneficial from an ergonomics standpoint, actually led to subjects selecting to organise work such that off-times (idle times) were reduced. In contrast, active 'on' times were not affected much by autonomy. These results point to a reason that piecework would be associated with increased risk for musculoskeletal disorders.

Circulating endothelial progenitor cells and erectile dysfunction: possibility of nutritional intervention?

To provide an overview of molecular and cellular processes involved in erectile dysfunction (ED) with emphasis on circulating endothelial progenitor cells (EPC) and discuss possible nutraceutical means of intervention. A review of literature on Pubmed related to EPC and ED was conducted. Patients with ED appear to possess a reduced number of circulating EPC, which is associated with poor endothelial function possibly as a result of underlying low-grade inflammation. Several studies support the possibility of improving erectile function by inhibition of inflammation as well as administration of various stem cell types. One particularly interesting approach is nutraceutical supplementation to increase circulating EPC, as demonstrated in the product Stem-Kine. Interventions aimed at increasing circulating EPC may have potential in treatment of vascular ED.

Vitamin D concentrations, endothelial progenitor cells, and cardiovascular risk factors

Our study aimed to establish the association of vitamin D status with the level of circulating endothelial progenitor cells (EPCs) and circulating angiogenic cells (CACs) and to demonstrate the effect of vitamin D on the level of lipoproteins responsible for increased cardiovascular risk and high blood pressure. 41 healthy adults were selected. EPCs were defined as CD34+/KDR+ cells, and CACs were defined as cells that expressed endothelial markers after incubation of mononuclear blood cells with endothelial growth factors during 5 days. We found a positive association between EPCs, CACs and the level of vitamin D and an inverse correlation between several subclasses of lipoproteins. The level of vitamin D higher than 40 ng/ml demonstrated a positive effect on regulation of blood pressure, and there was significant difference in cholesterol/HDL ratio, very low-density lipoproteins, and triglycerides for groups of subjects with varying levels of vitamin D.

Big and slow: phylogenetic estimates of molecular evolution in baleen whales (suborder mysticeti)

Baleen whales are the largest animals that have ever lived. To develop an improved estimation of substitution rate for nuclear and mitochondrial DNA for this taxon, we implemented a relaxed-clock phylogenetic approach using three fossil calibration dates: the divergence between odontocetes and mysticetes approximately 34 million years ago (Ma), between the balaenids and balaenopterids approximately 28 Ma, and the time to most recent common ancestor within the Balaenopteridae approximately 12 Ma. We examined seven mitochondrial genomes, a large number of mitochondrial control region sequences (219 haplotypes for 465 bp) and nine nuclear introns representing five species of whales, within which multiple species-specific alleles were sequenced to account for within-species diversity (1-15 for each locus). The total data set represents >1.65 Mbp of mitogenome and nuclear genomic sequence. The estimated substitution rate for the humpback whale control region (3.9%/million years, My) was higher than previous estimates for baleen whales but slow relative to other mammal species with similar generation times (e.g., human-chimp mean rate > 20%/My). The mitogenomic third codon position rate was also slow relative to other mammals (mean estimate 1%/My compared with a mammalian average of 9.8%/My for the cytochrome b gene). The mean nuclear genomic substitution rate (0.05%/My) was substantially slower than average synonymous estimates for other mammals (0.21-0.37%/My across a range of studies). The nuclear and mitogenome rate estimates for baleen whales were thus roughly consistent with an 8- to 10-fold slowing due to a combination of large body size and long generation times. Surprisingly, despite the large data set of nuclear intron sequences, there was only weak and conflicting support for alternate hypotheses about the phylogeny of balaenopterid whales, suggesting that interspecies introgressions or a rapid radiation has obscured species relationships in the nuclear genome.

Safety and efficacy of glargine compared with NPH insulin for the treatment of Type 2 diabetes: a meta-analysis of randomized controlled trials

AIMS

We systematically analysed evidence from randomized controlled trials (RCTs) examining the safety and efficacy of neutral protamine Hagedorn (NPH) insulin and glargine in the management of adults with Type 2 diabetes.

METHODS

Studies were identified by searching medline (1966-March 2007), embase (1974-2007), American Diabetes Association abstract database and the Cochrane Central Register of Controlled Trials using Medical Subject Headings (MeSH) diabetes mellitus, Type 2, insulin, insulin isophane, hypoglycaemic agents and the keywords glargine and NPH. Data on study design, participants, fasting plasma glucose (FPG), glycated haemoglobin (HbA(1c)), body weight and hypoglycaemia were independently abstracted by two investigators using a standardized protocol.

RESULTS

Data from a total of 4385 participants in 12 RCTs were pooled using a random-effects model. The mean net change (95% confidence interval) for FPG, HbA(1c) and body weight for patients treated with NPH insulin as compared with glargine was 0.21 mmol/l (-0.02 to 0.45), 0.08% (-0.04 to 0.21) and -0.33 kg (-0.61 to -0.06), respectively, with negative values favouring NPH and positive values favouring glargine. More participants experienced symptomatic and nocturnal hypoglycaemia on NPH than glargine, but there was no significant difference in confirmed or severe episodes.

CONCLUSIONS

We identified no difference in glucose-lowering between insulin glargine and NPH insulin, but less patient-reported hypoglycaemia with glargine and slightly less weight gain with NPH in adults with Type 2 diabetes.

Effect of parental smoking on cotinine levels in newborns

BACKGROUND

Smoking is a major risk factor for cot death. Many infants smoke passively as a result of parental smoking. This paper reports on infants exposed to a smoking environment and how they accumulate metabolites of cigarette smoke, such as cotinine, which may be physiologically harmful.

AIM

To assess cotinine levels in infants of smoking parents.

METHOD

Cotinine excretion in urine was assessed in 104 infants, of whom 71 had smoking parents and 33 had non-smoking parents. All cotinine levels were measured at approximately 12 weeks of age. The subjects were selected from a database of infants in developmental physiological studies which assessed the impact of various factors on early postnatal development.

RESULTS

On average babies with at least one parent who was a current cigarette smoker excreted 5.58 (95% CI 3.4 to 9.5) times as much cotinine in the urine as did the babies of non-smoking parents. Maternal smoking was the largest contributing factor. Co-sleeping (p = 0.037) and the minimum room temperature (p = 0.028) were significant contributory factors.

CONCLUSION

Infants from smoking households accumulate cotinine, a metabolite of nicotine, which may have a detrimental effect on the cardiorespiratory system.

An investigation of obese adults? views of the outcomes of dietary treatment

BACKGROUND

Although recommendations about the treatment of obesity have been well documented, there is little research into how obese individuals view the outcomes of dietary treatment. It has been suggested that patient involvement in evaluating treatment outcomes may help target issues to assist with the ongoing improvement of dietetic services. The aim of this qualitative study was to collect patients' views on the dietetic service, the treatment outcomes in terms of lifestyle change and the impact that attending the dietetic service had on their lives in order to improve dietetic treatment, and to assist in the selection of appropriate outcome measurements in the future.

METHODS

Semi-structured interviews were conducted with 24 obese patients attending dietetic clinics in Ayrshire, West of Scotland for weight management (advice on healthy eating and physical activity to achieve an energy deficit). Patients' views were transcribed, grouped and coded using content analysis.

RESULTS

Views included the importance of attending the dietitian for support to achieve weight management and a need to 'feel accountable to someone'. Interviewees valued information provided regarding diet, physical activity, behavioural strategies and the risks of obesity. Patients described the impact of obesity on their lives and identified changes to their lifestyles and health since attending the dietitian. They also identified barriers to change, e.g. feeling frustrated and overwhelmed about the changes necessary.

CONCLUSION

This study extends the current knowledge of patients' views of their treatment outcomes, which may be important in helping dietitians devise appropriate patient-centred outcome measures. However, as this is a small sample, further long term research into a wider range of current and discharged patients' views is required.

How few whales were there after whaling? Inference from contemporary mtDNA diversity

Reconstructing the history of exploited populations of whales requires fitting a trajectory through at least three points in time: (i) prior to exploitation, when abundance is assumed to be at the maximum allowed by environmental carrying capacity; (ii) the point of minimum abundance or 'bottleneck', usually near the time of protection or the abandonment of the hunt; and (iii) near the present, when protected populations are assumed to have undergone some recovery. As historical abundance is usually unknown, this trajectory must be extrapolated according to a population dynamic model using catch records, an assumed rate of increase and an estimate of current abundance, all of which have received considerable attention by the International Whaling Commission (IWC). Relatively little attention has been given to estimating minimum abundance (N(min)), although it is clear that genetic and demographic forces at this point are critical to the potential for recovery or extinction of a local population. We present a general analytical framework to improve estimates of N(min) using the number of mtDNA haplotypes (maternal lineages) surviving in a contemporary population of whales or other exploited species. We demonstrate the informative potential of this parameter as an a posteriori constraint on Bayesian logistic population dynamic models based on the IWC Comprehensive Assessment of the intensively exploited southern right whales (Eubalaena australis) and published surveys of mtDNA diversity for this species. Estimated historical trajectories from all demographic scenarios suggested a substantial loss of mtDNA haplotype richness as a result of 19th century commercial whaling and 20th century illegal whaling by the Soviet Union. However, the relatively high rates of population increase used by the IWC assessment predicted a bottleneck that was implausibly narrow (median, 67 mature females), given our corrected estimates of N(min). Further, high levels of remnant sequence diversity (theta) suggested that pre-exploitation abundance was larger than predicted by the logistic model given the catch record, which is known to be incomplete. Our results point to a need to better integrate evolutionary processes into population dynamic models to account for uncertainty in catch records, the influence of maternal fidelity on metapopulation dynamics, and the potential for inverse density dependence (an 'Allee effect') in severely depleted populations.

Evolutionary diversity in polystomatids infecting tetraploid and octoploid Xenopus in East African highlands: biological and molecular evidence

Species of Protopolystoma are monogenean flukes that only infect allopolyploid hosts in the anuran genus Xenopus. Multivariate analyses of morphometric sclerite characters in the nominal species Protopolystoma simplicis suggest that morphologically distinguishable populations occur in the tetraploid host, Xenopus laevis victorianus, and in each of the octoploid hosts, X. vestitus and X. wittei. The species-level divergence of a lineage specific to X. laevis is supported by sequence variation in the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. Protopolystoma simplicis from X. laevis is redesignated P. microsclera n. sp., with P. simplicis being retained for populations in octoploid hosts. This division is consistent with large differences in egg hatching schedule, fixed differences at the mannose-6-phosphate isomerase and fumarate hydratase loci, and host-specificity in experimental analyses. Although the respective P. simplicis populations in X. vestitus and X. wittei also show significant diversity in allozyme expression, morphometrics and egg hatching schedule, they are retained in the same species because their level of mitochondrial DNA divergence is similar to that found within other Protopolystoma species. The consequences of splitting P. simplicis for a recent interpretation of the origin of Protopolystoma faunas in octoploid Xenopus spp. is discussed.

Heterogeneous interspecific interactions in a host-parasite system

Macroparasites of vertebrates usually occur in multi-species communities, producing infections whose outcome in individual hosts or host populations may depend on the dynamics of interactions amongst the different component species. Within a single co-infection, competition can occur between conspecific and heterospecific parasite individuals, either directly or via the host's physiological and immune responses. We studied a natural single-host, multi-parasite model infection system (polystomes in the anuran Xenopus laevis victorianus) in which the parasite species show total interspecific competitive exclusion as adults in host individuals. Multi-species infection experiments indicated that competitive outcomes were dependent on infection species composition and strongly influenced by the intraspecific genetic identity of the interacting organisms. Our results also demonstrate the special importance of temporal heterogeneity (the sequence of infection by different species) in competition and co-existence between parasite species and predict that developmental plasticity in inferior competitors, and the induction of species-specific host resistance, will partition the within-host-individual habitat over time. We emphasise that such local (within-host) context-dependent processes are likely to be a fundamental determinant of population dynamics in multi-species parasite assemblages.

Patient-centred outcomes in dietary research

INTRODUCTION

Current health policy stresses the need to take patients' views into account in the provision of health care, including involvement in the process of care and determining the outcome(s) of treatment. It is unclear whether patients undergoing dietary treatment have been consulted on their views.

METHODS

A literature review, searching electronic databases and hand searching dietetic journals, of dietary intervention research was carried out to identify if patients' views were sought in determining outcomes.

RESULTS

Searching uncovered a total of 28 papers reporting the results of studies of dietary interventions where patients views were sought in the measurement of outcome, however little detail was given about patient(s) involvement and whether the use of the measures influenced future care.

FUTURE WORK

Should address the issue of patient involvement in the determination of outcome and how this then influences future care.

Immunity, immunoregulation and the ecology of trichuriasis and ascariasis

Immune responses to human roundworm (Ascaris lumbricoides) and whipworm (Trichuris trichiura) and their role in controlling worm populations are reviewed. Recent immunoepidemiological data implicate T(H)2-mediated responses in limiting A. lumbricoides and T. trichiura populations. Reinfection studies further suggest that IL-5 cytokine responses are negatively associated with adult recruitment in T. trichiura but not A. lumbricoides and may therefore be involved in negative intraspecific and interspecific interactions mediated through the host immune system. The importance of inducible immunoregulatory networks in the ecology of the host-parasite relationship is considered, with particular regard to possible manipulative strategies by the parasites. This aspect of the worms' interaction with the host immune system is both poorly known and potentially central to an understanding of parasite population dynamics and the evolutionary pressures that have shaped present-day host-parasite associations. Some possible implications of worm-mediated immunomodulation for the occurrence of bystander infectious diseases in human populations and the management of de-worming programmes are also discussed.

Cytokine response profiles predict species-specific infection patterns in human GI nematodes

This study investigated associations between pre-treatment cytokine expression and infection patterns, before and after de-worming, in humans exposed to two gastrointestinal nematode species. Quantitative measures of Ascaris lumbricoides and Trichuris trichiura infection (based on faecal egg counts) were estimated immediately before and 8-9 months after treatment in a Cameroonian population. Whole blood cytokine responses to parasite-derived antigens were assayed immediately pre-treatment. An overall measure of the tendency towards species-specific infection (increasing with A. lumbricoides faecal egg counts and decreasing with T. trichiura faecal egg counts) was significantly positively related to IL-10 levels in older (14-57 year) hosts. There was a significant negative influence of IL-5 on reinfection probability in T. trichiura but not A. lumbricoides. This effect coincided with reduced reinfection success in T. trichiura compared to A. lumbricoides. T(H)2 cytokine expression by younger hosts (4-13 year) was negatively associated with contemporary A. lumbricoides faecal egg counts before treatment. Following treatment, the pre-treatment T(H)2 cytokine expression data for younger hosts (now reflecting responsiveness 8-9 months in the past) were negatively associated with T. trichiura faecal egg counts. Taken together, these observations suggest a successional interaction between T(H)2-driven immune responses and species infection over time. However, any differential effects of the measured immune responses on species-specific recruitment, maturation and mortality were superimposed upon (and outweighed by) the effects of other factors favouring coinfection.

Early physiological development of infants with intrauterine growth retardation

OBJECTIVES

To assess the patterns of early postnatal physiological adaptation and maturation in intrauterine growth retarded (IUGR) infants by measuring changes in sleeping deep body temperature, heart rate, and concentrations of urinary cortisol.

SETTING

At home.

PATIENTS

Sixty five IUGR babies and 127 controls matched for sex, social class, and levels of parental smoking.

RESULTS

Night time sleeping deep body temperature, heart rate, and cortisol excretion fell with age, eventually establishing an adult type diurnal rhythm of physiological function. Minimum overnight temperature showed a linear decline with age (p < 0.001), but the IUGR infants and the controls had significant differences in intercept (p = 0.007) and slope (p = 0.02). The estimated rate of decline per week was 0.020 degrees C for IUGR infants and 0.031 degrees C for controls. Maximum temperature did not show similar changes. IUGR infants had a mean (SE) age adjusted minimum overnight heart rate that was 4.2 (1.5) beats/min (p = 0.005) higher than controls. Overnight cortisol/creatinine ratios declined with age at a rate of 4.1% per week (log ratio -0.421 (0.0165), p = 0.01), but the ratio for IUGR infants was on average 42% higher (log ratio 0.35 (0.11), p = 0.002) than for controls of the same age. Morning cortisol concentrations did not show a similar pattern.

CONCLUSIONS

Postnatal physiological adaptation and maturation of IUGR infants is slower than normal and therefore they remain in a physiologically immature state for longer. The higher heart rates and greater cortisol excretion in such infants may be precursors to hypertension and cardiovascular disease seen in adults.

Signs and symptoms of illness in early infancy: associations with sudden infant death

AIMS

to describe a pattern of illness in "normal" infants, and to assess to what extent this may differ in infants who die suddenly and unexpectedly.

METHODS

All infants are on the CONI (Care of the Next Infant) scheme in which mothers record symptoms and signs of illness prospectively, on a daily basis from birth to approximately age 6 months. The symptoms of infants who die suddenly and unexpectedly are compared with those of a consecutive sample of infants who survive. Twenty one babies died suddenly, of whom 11 were cot deaths and 10 had "known causes" of death. Ninety eight infants who survived were used as consecutive controls. Prospective daily records of the presence or absence of 26 signs and symptoms were kept by all of the mothers, commencing at birth and lasting an average of 176 days in survivors; 84 days in SIDS; and 93 days in infants who died of known causes.

RESULTS

Standardised for age and the time of year, on any given day, the mothers of the SIDS infants were over eight times more likely to record their child as being pale, six times more likely to be sweating, and twice as likely to be irritable. Other signs and symptoms which were three times more likely to be recorded were sore gums, dry stools, and coldness. Infants who died of known causes generally had fewer symptoms.

CONCLUSIONS

Cot death infants have a range of symptoms which appear to be of a general nature, and not related to any one system. Symptoms are seen throughout life and not related to the time of death.

Postlarval Protopolystoma spp. kidney infections in incompatible Xenopus spp. induce weak resistance to heterospecifics

Protopolystoma xenopodis and Protopolystoma orientalis are polystomatid monogeneans respectively specific to the parapatric anurans Xenopus laevis and Xenopus muelleri. Parasite larval stages may invade the kidneys of foreign Xenopus spp. but die before migration to the definitive urinary bladder site. Laboratory experiments to assess the effect of a primary incompatible kidney infection on a secondary compatible infection found: (1) a small, significant decrease in the survivorship of P. xenopodis kidney stages (23-37 days p.i. at 25 degrees C) in X. laevis laevis previously challenged with P. orientalis; (2) a significant effect of prior P. orientalis challenge on P. xenopodis development and establishment in the urinary bladder of X. laevis 100 days p.i. (at 21 degrees C); (3) no effect of prior P. xenopodis challenge on adult P. orientalis establishment in X. muelleri (at 21 degrees C), but a significant negative influence on reproductive output (days 0-50 post-patency). Partial cross-resistance to heterospecifics may therefore be induced by Protopolystoma spp. infections in the kidneys of an incompatible host, demonstrating that at least some elements of the host response are non-species specific. The effects observed were weak compared to the strong host resistance known to be generated by an established compatible primary infection with respect to conspecifics. This difference suggests that strong acquired resistance to Protopolystoma species is species-specific and/or induced only by older stages surviving in compatible hosts.

Health and performance of Holstein calves that suckled or were hand-fed colostrum and were fed one of three physical forms of starter

Intake of colostrum by neonatal calves and early transition to calf starter are two important factors in successful calf programs. Thirty-one Holstein calves were used to determine health and performance of calves that were 1) allowed to remain with their dams for 3 d and suckle (suckled calves) or were removed from their dams and fed colostrum only by bottle (bottle calves); and were 2) fed ground, pelleted, or textured starters, formulated to be isonitrogenous. Bottle calves were removed from their dams at birth, fed 2.84 L of colostrum, placed in individual hutches, and fed 1.89 L of colostrum 12 h after the first feeding. Suckled calves were removed from their dams after 3 d and placed in individual hutches. Once calves were housed in hutches, they were fed 2 L of whole milk twice daily and were provided starters and water beginning on d 3. Calves were weighed at birth and weekly for 6 wk. Blood samples were obtained at birth, 24 h, and weekly for serum protein determination. Starter intake, fecal scores, and electrolyte treatments were recorded daily. Weaning began when calves had consumed 0.68 kg starter for 2 d consecutively. There were no differences in treatment means between suckled and bottle calves for total gain, grain consumption, days with fecal scores >2, or electrolyte treatments per calf. Average days to weaning was greater for bottle calves compared with suckled calves. Mean serum protein concentration at 24 h was greater for bottle (6.0 g/dl) compared with suckled calves (5.8 g/dl) and only 2 of 15 bottle calves had serum protein concentrations <5.0 g/dl compared with 6 of 16 suckled calves. For starter treatments, calves fed textured starter consumed more total grain, were weaned earlier, and weighed more at 6 wk of age than calves fed pelleted starter. Based on 24-h serum protein concentrations, transfer of passive immunity was greater for bottle calves compared with suckled calves.

Parasite infectivity to hybridising host species: a link between hybrid resistance and allopolyploid speciation?

Variation in host-specific infectivity was studied in monogenean polystome parasites (Protopolystoma spp.) of the interfertile, parapatric anurans Xenopus laevis laevis and Xenopus muelleri. Laboratory-raised host F1 hybrids were resistant to parasites respectively specific to each parent taxon in nature. This resistance occurred against parasite isolates from both inside and outside a host hybrid/sympatric zone (and no isolate was compatible with the foreign host species under experimental conditions). Geographical Protopolystoma xenopodis isolates showed variable infectivity to a single full-sib group of their usual host, X. l. laevis, and strains with high or low infectivity to these sibs co-occurred in spatially distant local areas (separated by 1,700 km). The host compatibility of P. xenopodis was also subject to host genotypexparasite genotype interactions. Refractoriness to some parasites or pathogens, as a consequence of hybridisation, may have conferred a selective advantage on the allopolyploid pathway by which most Xenopus spp. are believed to have evolved.