Comparing post-traumatic stress severity in professional and volunteer Australian firefighters

BACKGROUND

While extensive research has highlighted increased risk for post-traumatic stress disorder (PTSD) in firefighters, previous research has yielded mixed results regarding the role of work status (professional versus volunteer) in the development of psychopathological symptoms.

AIMS

To explore the predictive strength of work status on PTSD or post-traumatic stress symptom severity in a large sample of professional (PFFs) and volunteer (VFFs) Australian firefighters exposed to operational work-related trauma.

METHODS

The stratified random sample comprised 1317 PFFs (n = 1148 (87%) males and 13%, n = 169 (13%) females) and 898 VFFs (n = 744 (83%) males and n = 154 (17%) females) who reported having experienced trauma while working or volunteering. Participants completed demographic, health and work-related questions and mental health measures of stress, trauma, PTSD, social support and use of mental health prevention programmes.

RESULTS

The results revealed a significant relationship between work status and PTSD, with PFFs reporting higher levels of PTSD symptom severity compared to VFFs. This association persisted after controlling for demographics, health, stress away from work, social support and use of organizational mental health support programmes (debriefing and face-to-face training for mental and physical self-care).

CONCLUSIONS

This study suggests the importance of work status in PTSD amongst Australian firefighters exposed to operational trauma. Future research is needed to substantiate our findings and examine why PFFs may be more prone to developing PTSD. Implications for the provision of mental health programmes offered by fire organizations to their members are discussed.

Common mental disorder and suicidality among doctors: differences by specialty

BACKGROUND

Common mental disorders (CMDs) and suicidal ideation (SI) are prevalent among doctors, yet limited evidence exists investigating the relationship of specialty area to these outcomes.

AIMS

This study aimed to determine the prevalence of likely CMD and SI among doctors and to investigate whether likelihood of these outcomes varied by area of medical specialty.

METHODS

A secondary analysis of a representative national survey of 12,252 Australian doctors was conducted. Demographic and work-related variables, SI and CMD (GHQ-28), were assessed among doctors (n = 7037; 57%) working in a range of specialty areas. Logistic regression was used to examine the association between specialty and mental health outcomes in unadjusted and adjusted models.

RESULTS

Almost one-quarter of doctors (n = 1560; 23%) reported symptom levels indicating likely CMD whilst 9% (n = 667) reported SI in the last year. Doctors in surgery (adjusted odds ratio [OR] = 0.73, 95% confidence interval [CI] 0.54-0.97, P = 0.03) were at significantly lower risk of CMD than General Practitioners (GPs), whilst doctors in anaesthetics (adjusted OR = 1.45; 95% CI 1.09-1.93, P = 0.01) and paediatrics (adjusted OR = 1.88; 95% CI 1.02-3.47, P = 0.04) were at significantly higher risk of experiencing SI compared to GPs after accounting for confounders.

CONCLUSIONS

Results demonstrated that doctors in Australia working in certain specialties, specifically anaesthetics and paediatrics, were at significantly greater risk of suicidal ideation compared to GPs after accounting for confounders. Interventions to address CMD and SI among doctors in all specialties remain urgently needed.

The impact of depression, anxiety and comorbidity on occupational outcomes

BACKGROUND

Anxiety and depression account for considerable cost to organizations, driven by both presenteeism (reduced performance due to attending work while ill) and absenteeism. Most research has focused on the impact of depression, with less attention given to anxiety and comorbid presentations.

AIMS

To explore the cross-sectional relationship between depression and anxiety (individually and comorbidly) on workplace performance and sickness absence.

METHODS

As part of a larger study to evaluate a mental health app, 4953 working Australians were recruited. Participants completed in-app assessment including demographic questions, the Patient Health Questionnaire-9, two-item Generalized Anxiety Disorder and questions from the World Health Organization Health and Work Performance Questionnaire. Cut-off scores were used to establish probable cases of depression alone, anxiety alone and comorbidity.

RESULTS

Of the total sample, 7% met cut-off for depression only, 13% anxiety only, while 16% were comorbid. Those with comorbidity reported greater symptom severity, poorer work performance and more sickness absence compared to all other groups. Presenteeism and absenteeism were significantly worse in those with depression only and anxiety only compared to those with non-clinical symptom levels. Although those with depression alone tended to have poorer outcomes than the anxiety-only group, when sample prevalence rates were considered, the impact on presenteeism was comparable.

CONCLUSIONS

Workplace functioning is heavily impacted by depression and anxiety both independently and where they co-occur. While comorbidity and more severe depression presentations stand out as impairing, workplace interventions should also prioritize targeting of anxiety disorders (and associated presenteeism) given their high population prevalence.

A prospective study of pre-employment psychological testing amongst police recruits

BACKGROUND

Pre-employment psychological screening to detect psychological vulnerability is common amongst emergency service organizations worldwide, yet the evidence for its ability to predict poor mental health outcomes is limited with published studies looking at post-recruitment research data rather than data collected by the organizations themselves.

AIMS

The present study sought to investigate the ability of pre-employment screening to predict later psychological injury-related absenteeism amongst police officers.

METHODS

A nested case-control study using prospective data was conducted. One hundred and fifty police officers with a liability-accepted psychological injury were matched to a control group of 150 psychologically healthy officers. Conditional logistic regression was used to examine associations between Minnesota Multiphasic Personality Inventory-2 (MMPI-2) scales measuring factors research has shown to predict psychological injury (Neuroticism, Psychoticism, Introversion, Disconstraint and Aggressiveness) and psychopathology (Depression, Anxiety and post-traumatic stress disorder [PTSD]) with subsequent psychological injury.

RESULTS

Contrary to expectations, we were unable to demonstrate any association between validated pre-employment measures of personality and psychopathology with mental health outcomes amongst newly recruited police officers over a 7-year follow-up.

CONCLUSIONS

Other measures may be better able to predict future mental health problems in police recruits.

A meta-regression of the impact of policy on the efficacy of individual placement and support

OBJECTIVE

Individual placement and support (IPS) has shown consistently better outcomes on competitive employment for patients with severe mental illness than traditional vocational rehabilitation. The evidence for efficacy originates from few countries, and generalization to different countries has been questioned. This has delayed implementation of IPS and led to requests for country-specific RCTs. This meta-analysis examines if evidence for IPS efficacy can be generalized between rather different countries.

METHODS

A systematic search was conducted according to PRISMA guidelines to identify RCTs. Overall efficacy was established by meta-analysis. The generalizability of IPS efficacy between countries was analysed by random-effects meta-regression, employing country- and date-specific contextual data obtained from the OECD and the World Bank.

RESULTS

The systematic review identified 27 RCTs. Employment rates are more than doubled in IPS compared with standard vocational rehabilitation (RR 2.07 95% CI 1.82-2.35). The efficacy of IPS was marginally moderated by strong legal protection against dismissals. It was not moderated by regulation of temporary employment, generosity of disability benefits, type of integration policies, GDP, unemployment rate or employment rate for those with low education.

CONCLUSIONS

The evidence for efficacy of IPS is very strong. The efficacy of IPS can be generalized between countries.

Managers' response to mental health issues among their staff

Background

Many organizations are implementing mental health training for managers to facilitate better communication between managers and employees suffering from mental health problems. Much of this training focuses on improving managers' mental health literacy and reducing stigma. However, it is unclear whether this focus is appropriate or whether other targets, such as improving skills and confidence, should be given greater consideration.

Aims

To test whether knowledge, attitudes and confidence are associated with managers' behavioural responses to mental health issues among their staff.

Methods

Managers from a large Australian fire and rescue service completed a questionnaire addressing their knowledge, attitudes, confidence and behavioural responses when managing employee mental health issues. The relationship was assessed using logistic regression. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated.

Results

Eighty-five managers responded (response rate 66%). Managers' confidence was the strongest predictor of their behaviour. Managers who felt confident discussing mental health were significantly more likely to make contact with an employee who was suspected to be suffering from a mental illness (OR 15.79, 95% CI 3.03-82.37, P < 0.01) or was on sickness leave for mental health reasons (OR 19.84, 95% CI 2.25-175.15, P < 0.01). Non-stigmatizing attitudes towards mental illness also significantly predicted contact with a staff member off work due to mental health problems (OR 5.22, 95% CI 1.21-22.54, P < 0.05).

Conclusions

Our findings suggest that manager mental health training should focus on building their confidence and reducing stigma in order to have the greatest chance of altering workplace practices.

A blended face-to-face and smartphone intervention for suicide prevention in the construction industry: protocol for a randomized controlled trial with MATES in Construction

BACKGROUND

Construction workers are at elevated risk of suicide. MATES in Construction (MATES) is one of the few suicide prevention programs that explicitly address this problem. The MATES program includes an integrated system of services that supports prevention, early intervention and recovery (i.e., primary, secondary and tertiary prevention) for mental health problems among construction workers. In this protocol, we describe a proposed evaluation of MATESmobile, an electronic platform which will be accessed by workers who have undergone MATES training.

METHODS/DESIGN

In this protocol, we describe a Randomised Controlled Trial (RCT) which seeks to assess whether MATESmobile results in improved literacy regarding suicide prevention, and improved help-seeking and help-offering attitudes among those who have attended MATES training. Secondary outcomes include changes in suicide ideation, suicide attempt and psychological distress. Workers will be recruited prior to MATES face-to-face training. In total, 295 workers will be randomly assigned to the intervention condition (MATESmobile + face-to-face training) and 295 will be randomly allocated to the control (face-to-face training). The intervention will run for 8 weeks. Assessments will be run immediately post intervention, and at 3, 6, and 12 months DISCUSSION: MATESmobile offers the potential to reinforce and enhance the effects of face-to-face training, resulting in greater skills and knowledge in suicide prevention, as well as a reduction in suicidality and distress.

TRIAL REGISTRATION

This trial is registered with the Australian New Zealand Clinical Trials Registry ( ACTRN12619000625178 ; 26 April 2019).

A smartphone application for treating depressive symptoms: study protocol for a randomised controlled trial

BACKGROUND

Depression is a commonly occurring disorder linked to diminished role functioning and quality of life. The development of treatments that overcome barriers to accessing treatment remains an important area of clinical research as most people delay or do not receive treatment at an appropriate time. The workplace is an ideal setting to roll-out an intervention, particularly given the substantial psychological benefits associated with remaining in the workforce. Mobile health (mhealth) interventions utilising smartphone applications (apps) offer novel solutions to disseminating evidence based programs, however few apps have undergone rigorous testing. The present study aims to evaluate the effectiveness of a smartphone app designed to treat depressive symptoms in workers.

METHODS

The present study is a multicentre randomised controlled trial (RCT), comparing the effectiveness of the intervention to that of an attention control. The primary outcome measured will be reduced depressive symptoms at 3 months. Secondary outcomes such as wellbeing and work performance will also be measured. Employees from a range of industries will be recruited via a mixture of targeted social media advertising and Industry partners. Participants will be included if they present with likely current depression at baseline. Following baseline assessment (administered within the app), participants will be randomised to receive one of two versions of the Headgear application: 1) Intervention (a 30-day mental health intervention focusing on behavioural activation and mindfulness), or 2) attention control app (mood monitoring for 30 days). Participants will be blinded to their allocation. Analyses will be conducted within an intention to treat framework using mixed modelling.

DISCUSSION

The results of this trial will provide valuable information about the effectiveness of mhealth interventions in the treatment of depressive symptoms in a workplace context.

TRIAL REGISTRATION

The current trial is registered with the Australian and New Zealand Clinical Trials Registry ( ACTRN12617000547347 , Registration date: 19/04/2017).

Designing smartphone mental health applications for emergency service workers

Background

Emergency service workers are often exposed to trauma and have increased risk of a range of mental health (MH) conditions. Smartphone applications have the potential to provide this group with effective psychological interventions; however, little is known about the acceptability and preferences regarding such initiatives.

Aims

To describe the preferences and opinions of emergency service workers regarding the use of smartphone MH applications and to examine the impact of age on these preferences.

Methods

Participants were recruited from four metropolitan Fire and Rescue NSW stations and responded to questionnaire items covering three key domains: current smartphone use, potential future use and preferences for design and content as well as therapeutic techniques.

Results

Overall, approximately half the sample (n = 106) claimed they would be interested in trying a tailored emergency-worker MH smartphone application. There were few differences between age groups on preferences. The majority of respondents claimed they would use an app for mental well-being daily and preferred terms such as 'well-being' and 'mental fitness' for referring to MH. Confidentiality, along with a focus on stress, sleep, exercise and resiliency were all considered key features. Behavioural therapeutic techniques were regarded most favourably, compared with other therapies.

Conclusions

Emergency workers were interested in utilizing smartphone applications focused on MH, but expressed clear preferences regarding language used in promotion, features required and therapeutic techniques preferred.

Case-specific colleague guidance for general practitioners' management of sickness absence

Background

General practitioners (GPs) report sickness absence certification as challenging. They express need for support with functional assessment beyond guidelines and reforms. Case-specific collegial one-to-one guidance for other clinical topics has proved popular with GPs and may be an acceptable and effective way to improve GPs skills and competence in sickness absence certification.

Aims

To present a new model of case-specific colleague guidance focusing on the management of long-term sickness absence and to describe its feasibility in terms of application and reception among GPs, and also GPs' self-reports of effects on their practice.

Methods

Randomly selected GPs received case-specific collegial guidance over a 12-month period, in two Norwegian trials, delivered by former GPs employed by the social security administration. We measured reception and perceived effects by GPs' self-report and registered participation and withdrawal rates.

Results

The participation rate (n = 165) was 94%, and no GPs withdrew during training. Among the 116 GPs responding to the survey (70%), 112 (97%; 95% CI 92-99) stated they would recommend it to their colleagues. Considerable benefit from the guidance was reported by 68 (59%; 95% CI 50-68). The GPs self-reported other effects on their sickness absence certification, specifically an increased use of part-time sickness absence (Fit-Note equivalent).

Conclusions

This model of case-specific colleague guidance to aid GPs' management of long-term sickness absence is feasible and was popular. This type of guidance was perceived by GPs to be somewhat beneficial and to alter their sickness absence certification behaviour, though the true impact requires further testing in controlled trials.

eHealth interventions for the prevention of depression and anxiety in the general population: a systematic review and meta-analysis

BACKGROUND

Anxiety and depression are associated with a range of adverse outcomes and represent a large global burden to individuals and health care systems. Prevention programs are an important way to avert a proportion of the burden associated with such conditions both at a clinical and subclinical level. eHealth interventions provide an opportunity to offer accessible, acceptable, easily disseminated globally low-cost interventions on a wide scale. However, the efficacy of these programs remains unclear. The aim of this study is to review and evaluate the effects of eHealth prevention interventions for anxiety and depression.

METHOD

A systematic search was conducted on four relevant databases to identify randomized controlled trials of eHealth interventions aimed at the prevention of anxiety and depression in the general population published between 2000 and January 2016. The quality of studies was assessed and a meta-analysis was performed using pooled effect size estimates obtained from a random effects model.

RESULTS

Ten trials were included in the systematic review and meta-analysis. All studies were of sufficient quality and utilized cognitive behavioural techniques. At post-treatment, the overall mean difference between the intervention and control groups was 0.25 (95% confidence internal: 0.09, 0.41; p = 0.003) for depression outcome studies and 0.31 (95% CI: 0.10, 0.52; p = 0.004) for anxiety outcome studies, indicating a small but positive effect of the eHealth interventions. The effect sizes for universal and indicated/selective interventions were similar (0.29 and 0.25 respectively). However, there was inadequate evidence to suggest that such interventions have an effect on long-term disorder incidence rates.

CONCLUSIONS

Evidence suggests that eHealth prevention interventions for anxiety and depression are associated with small but positive effects on symptom reduction. However, there is inadequate evidence on the medium to long-term effect of such interventions, and importantly, on the reduction of incidence of disorders. Further work to explore the impact of eHealth psychological interventions on long-term incidence rates.

Workplace interventions for common mental disorders: a systematic meta-review

Depression and anxiety disorders are the leading cause of sickness absence and long-term work incapacity in most developed countries. The present study aimed to carry out a systematic meta-review examining the effectiveness of workplace mental health interventions, defined as any intervention that a workplace may either initiate or facilitate that aims to prevent, treat or rehabilitate a worker with a diagnosis of depression, anxiety or both. Relevant reviews were identified via a detailed systematic search of academic and grey literature databases. All articles were subjected to a rigorous quality appraisal using the AMSTAR assessment. Of the 5179 articles identified, 140 studies met the inclusion criteria, of which 20 were deemed to be of moderate or high quality. Together, these reviews analysed 481 primary research studies. Moderate evidence was identified for two primary prevention interventions; enhancing employee control and promoting physical activity. Stronger evidence was found for CBT-based stress management although less evidence was found for other secondary prevention interventions, such as counselling. Strong evidence was also found against the routine use of debriefing following trauma. Tertiary interventions with a specific focus on work, such as exposure therapy and CBT-based and problem-focused return-to-work programmes, had a strong evidence base for improving symptomology and a moderate evidence base for improving occupational outcomes. Overall, these findings demonstrate there are empirically supported interventions that workplaces can utilize to aid in the prevention of common mental illness as well as facilitating the recovery of employees diagnosed with depression and/or anxiety.

Which patients are seen by an occupational psychiatry service?

BACKGROUND

Common mental disorders are the leading cause of sickness absence but are frequently misdiagnosed and undertreated. It is against this background that a specialist occupational psychiatry clinic was established at a London teaching hospital.

AIMS

To explore the nature of patients and complaints seen in the clinic and investigate whether this form of service provision reached patients who may have otherwise been missed in the gap between primary and secondary care.

METHODS

We reviewed the case notes of 51 consecutive new clinic assessments using a data extraction form, gathering information on socio-demographic and occupational details; the nature, duration and severity of symptoms [as assessed by Health of the Nation Outcome Scale (HoNOS)]; diagnosis; prior treatment and the outcome of the clinic appointment.

RESULTS

Only half of those seen in the new clinic were currently on sick leave. The most common diagnosis was depression with most having symptoms lasting longer than 9 months. Sixty-five per cent had a medium or high HoNOS rating. Although 75% had received treatment from their general practitioner, the majority remained functionally impaired, and only 31% had been seen in secondary care.

CONCLUSIONS

Specialist occupational psychiatry clinics do not replicate the work already being done by standard mental health services. Patients referred to a new specialist clinic within an occupational health department had chronic, debilitating psychiatric illnesses, which in many cases had failed to respond adequately to primary care treatment and were at risk of falling into the gap between primary and secondary services.

Common mental disorders and long-term sickness absence in a general working population. The Hordaland Health Study

OBJECTIVE

To examine and compare the prospective effect of the common mental disorders (CMD) anxiety and depression on duration and recurrence of sickness absence (SA), and to investigate whether the effect of CMD on SA is detectable over time.

METHOD

Information from a large epidemiological health study (N = 13 436) was linked with official records of SA episodes lasting ≥16 days up to 6 years after participation. Common mental disorders were assessed with the Hospital Anxiety and Depression Scale (HADS). Associations were analysed with Cox regression and multinomial logistic regression models controlling for potential covariates.

RESULTS

Comorbid anxiety and depression, and anxiety only were significant risk factors for SA after adjusting for covariates, whilst depression only was not. Anxiety and depression were stronger predictors for longer duration of SA episodes compared with shorter duration and associated with more frequent recurrence of SA. There was a general trend toward the effect of CMD on SA becoming weaker over time; however, the effect of anxiety only on SA remained stable throughout the follow-up.

CONCLUSION

Common mental disorders are long-lasting predictors of onset, duration and recurrence of SA. Anxiety appears to be a more important contributor to long-term SA than previously described in the literature.

Prospective evaluation of mental health training for occupational health practitioners

BACKGROUND

Occupational health (OH) practitioners need to be confident in identifying and managing mental health problems in the workforce.

AIMS

To evaluate the effectiveness of a one-day workshop in improving the knowledge, attitude and confidence of OH practitioners in detecting and managing depression, anxiety, suicide risk, alcohol misuse and drug abuse.

METHODS

Interactive mental health workshops for 164 OH practitioners held in five regions in England were evaluated by self-administered questionnaire. Data were collected immediately prior to the workshop (T1), immediately after the workshop (T2) and 4 months following the workshop (T3).

RESULTS

At T1, the response rate was 97% (159/164), 90% at T2 and 63% at T3. The mean improvement in participants' knowledge was 8% (95% CI 6-10) at T2 compared with T1. The biggest improvement was in participants with no previous training in the management of common mental health problems in the workplace, mean improvement 9% (95% CI 6-12). Participants' confidence improved in all areas assessed at T2, and the improvement in confidence compared with that at baseline was sustained at 4 months (T3). Participants reported using the knowledge gained in clinical practice in all topic areas covered. Use of knowledge gained at the workshop was significantly higher in those who had had previous training in managing common mental health disorders.

CONCLUSIONS

This one-day interactive workshop was a feasible and effective method of improving OH professionals' confidence, knowledge and application of skills in practice in key areas of mental health.

Personality disorders, common mental disorders and receipt of disability benefits: evidence from the British National Survey of Psychiatric Morbidity

BACKGROUND

Common mental disorders (CMDs) are associated with occupational impairment and the receipt of disability benefits (DBs). Little is known about the relationship between personality disorders (PDs) and work disability, and whether the association between CMDs and work disability is affected by the presence of co-morbid PDs. The aim of this study was to examine the association between DB and individual categories of PDs, with special attention to the effect of co-morbid CMDs on this association.

METHOD

The association between DB and PD was examined using data from the 2000 British National Survey of Psychiatric Morbidity. Probable PD caseness was identified using the Structured Clinical Interview for DSM-IV Personality Disorders (SCID-II) screening questionnaire. The impact of CMDs, assessed with the revised version of the Clinical Interview Schedule (CIS-R), was examined as a covariate and in a stratified analysis of co-morbidity. Other covariates included sociodemographic factors, long-standing illnesses and substance use.

RESULTS

Probable PD was associated with DB, with the strongest associations found for borderline, dependent and schizotypal PD. Antisocial PD was not associated with DB. The relationship between PD and DB was strongly modified by CMD, reducing the association from an odds ratio (OR) of 2.84 to 1.34 [95% confidence interval (CI) 1.00-1.79)]. In the stratified analysis, co-morbid PD and CMD showed a stronger association with DB than PD without CMD but, when fully adjusted, this effect was not significantly different from the association between CMD without PD.

CONCLUSIONS

Individuals screening positive for PD are more likely to experience severe occupational outcomes, especially in the presence of co-morbid CMD.

Depression and work performance: an ecological study using web-based screening

BACKGROUND

Depression is reported to be a major cause of illness-related sub-optimal work performance (presenteeism). However, the majority of studies examining presenteeism have relied on self-report measures of work performance. Furthermore, employers currently face a number of practical challenges in attempting to facilitate early identification of depression.

AIMS

To test whether a web-based screening tool for depression could be used successfully in the workplace and whether it was possible to detect an association between rates of depression and objective measures of impaired workgroup performance.

METHODS

All permanent employees of a telecommunications company with UK-based call centres were encouraged to complete a web-based psychological assessment using the Patient Health Questionnaire depression scale (PHQ-9). In addition to confidential individual level results, the tool was able to provide anonymized summary statistics for each workgroup. Four objective measures of work performance were collected for each workgroup.

RESULTS

During the study period, 1161 web-based PHQ-9 questionnaires were completed. There was a negative linear relationship between rates of depressive symptoms and the overall performance of a workgroup (P < 0.001). The linear relationship between depression and workgroup performance remained after controlling for gender balance, percent of temporary staff, employees' perceived level of engagement and satisfaction with their line manager (P < 0.01).

CONCLUSIONS

Workgroups with high levels of depressive symptoms tend to perform poorly. Computer-aided web-based screening for symptoms of depression is feasible in a work setting.

Work and common psychiatric disorders

Psychiatric disorders are now the most common reason for long-term sickness absence. The associated loss in productivity and the payment of disability benefits places a substantial burden on the economies of many developed countries. The occupational dysfunction associated with psychiatric disorders can also lead to poverty and social isolation. As a result the area of work and psychiatric disorders is a high priority for policymakers. There are two main agendas: for many researchers and clinicians the focus is on the need to overcome stigma and ensure people with severe psychiatric disorders have meaningful work; however the public health agenda predominantly relates to the more common disorders such as depression and anxiety, which contribute a greater burden of disability benefits and pensions. In this review we attempt to address this second agenda. The relatively sparse evidence available reveals a complex field with significant interplay between medical, psychological social and cultural factors. Sick leave can be a 'process' as well as an 'event'. In this review we propose a staged model where different risk and protective factors contribute to the onset of psychiatric disorders in the working population, the onset of short-term sickness absence, and the transition from short- to long-term absence. We also examine strategies to manage psychiatric disorder in the workforce with a view towards returning the employee to work. Our aim in this review is to highlight the complexity of the area, to stimulate debate and to identify important gaps in knowledge where further research might benefit both patients and wider society.

Pathogenesis of a bovine enterovirus-1 isolate in experimentally infected calves

The pathogenesis and virulence of Bovine enterovirus-1 (BEV-1) in cattle is largely unknown. Reports concerning its virulence suggest that there might be an association between BEV-1 infections and a range of diseases in cattle that vary from respiratory to enteric to reproductive disease and infertility. In the current study, the pathogenesis associated with acute infection of BEV-1 in calves experimentally inoculated with the Oklahoma isolate of BEV-1 was described. Although interpretation of the study was limited by lack of an effective control group, results suggest that an association between inoculation of BEV-1, virus localization, and the potential development of lesions in the brain and heart probably exists. In the experiment, BEV-1 virus localized to the terminal ileum, ileocecal and cecocolonic junctions, spiral colon, and ileocecal lymph nodes; BEV-1 virus was detected in the cytoplasm of enterocytes, lamina propria macrophages, endothelium, neurons of the submucosal and myenteric plexi, and lymphocytes of the submucosal lymphoid tissue. Although no clinical signs were noted following acute infection, BEV-1 was localized in the cerebellar white matter of a calf with encephalitis and in the heart of another calf with coronary arteritis. The current study suggests that the BEV-1 isolate is infectious to young calves and that BEV-1 potentially can have a similar pathogenesis to that observed in natural or experimental enterovirus infections in other species.

Reversible Fibroadenomatous Mammary Hyperplasia in Male and Female New Zealand White Rabbits Associated with Cyclosporine A Administration

All male and female New Zealand white rabbits in a limbal cell graft study developed marked generalized mammary gland hypertrophy. Postprocedural medications included ophthalmic 0.1% dexamethasone, ophthalmic 0.5% cyclosporine, and subcutaneous cyclosporine A. Cytologic examination revealed epithelial clusters with minimal malignant criteria. On histologic evaluation, there was diffuse glandular hyperplasia with mild cellular atypia and ductal ectasia separated by abundant hypercellular fibrous stroma, consistent with fibroadenomatous mammary gland hyperplasia. The hyperplasia resolved within 2 weeks of cessation of cyclosporine, and at necropsy identifiable mammary masses were not found. Very little has been reported about the use of cyclosporine in laboratory rabbits and its association with development of mammary gland hyperplasia. This is the first report in which administration of cyclosporine to male and female rabbits at a dose as low as 5 mg/kg/day induced benign fibroadenomatous mammary gland hyperplasia. This change regressed after cessation of the drug.

The relationship between prior psychiatric disorder and chronic fatigue: evidence from a national birth cohort study

BACKGROUND

Increased rates of psychiatric disorder have previously been reported in those diagnosed with chronic fatigue syndrome (CFS) or myalgic encephalomyelitis (ME), although the direction of causation in this relationship has not been established. We aimed to test the hypothesis that individuals with self-reported CFS/ME have increased levels of psychiatric disorder prior to the onset of their fatigue symptoms.

METHOD

A total of 5,362 participants were prospectively followed with various measures of personality, psychiatric disorder and fatigue levels collected over the first 43 years of their life. CFS/ME was identified through self-report during a semi-structured interview at age 53 years.

RESULTS

Thirty-four (1.1%) of the 3,035 subjects assessed at age 53 years reported a diagnosis of CFS/ME. CFS/ME was more common among females, but there was no association between CFS/ME and either social class, social mobility or educational level. Those with psychiatric illness between the ages of 15 and 36 years were more likely to report CFS/ME later in life with an odds ratio (OR, adjusted for sex) of 2.65 [95% confidence interval (CI) 1.26-5.57, p=0.01]. Increased levels of psychiatric illness, in particular depression and anxiety, were present prior to the occurrence of fatigue symptoms. There was a dose-response relationship between the severity of psychiatric symptoms and the likelihood of later CFS/ME. Personality factors were not associated with a self-reported diagnosis of CFS/ME.

CONCLUSIONS

This temporal, dose-response relationship suggests that psychiatric disorders, or shared risk factors for psychiatric disorders, are likely to have an aetiological role in some cases of CFS/ME.

Correlation of a T45S variant of apolipoprotein C1 with elevated BMI in persons of American Indian and Mexican ancestries

Obesity and diabetes are serious health problems for Americans and especially for those with American Indian or Mexican ancestry. A preliminary survey by protein analysis rather than classical nucleic acid sequencing methods has suggested a correlation between a newly discovered T45S variant of apolipoprotein C1 (ApoC1), found only in persons with American Indian or Mexican ancestry, and elevated body mass index (BMI). American Indians with the S45 ApoC1 variant (n=36) had an average of 9% higher BMI than those who had only T45 ApoC1 (n=192, P=0.029). Elevated rates of diabetes were reported for parents of subjects with the S45 protein (P=0.006). In five gender-matched sibling pairs, persons with Mexican ancestry showed a 1.34-fold higher BMI for those with S45 ApoC1 (P=0.022). This protein may contribute to the elevated rates of diabetes in relevant ethnic groups and might be more common in isolated populations.

Bisphosphonate–ciprofloxacin bound to Skelite™ is a prototype for enhancing experimental local antibiotic delivery to injured bone

Background

The risk of osteomyelitis after open bone fracture may be reduced by locally applied antibiotics. ENC-41-HP (E41), which comprises ciprofloxacin linked to a ‘bone seeking’ bisphosphonate, loaded on to carrier Skelite™ calcium phosphate granules (E41-Skelite™) has favourable in vitro characteristics for application to wounded bone. This study assessed E41-Skelite™ in a rat model of acute tibial osteomyelitis.

Methods

Mechanically induced tibial troughs were contaminated with approximately log10 4 colony forming units (c.f.u.) of Staphylococcus aureus (Cowan 1 strain) ‘resistant’ to E41 (minimum inhibitory concentration 8–16 µg/ml), lavaged and packed with Skelite™ alone, or with E41-Skelite™ slurry. Animals were killed at 24 h (n = 62), 72 h (n = 46) or 14 days (n = 12), and each tibia was assessed for S. aureus load (c.f.u./g tibia) and histological appearance (14 days only).

Results

At 24 and 72 h, the tibias of rats treated with E41-Skelite™ (n = 54) had a significantly lower mean(s.e.m.) load of S. aureus than animals that received Skelite™ alone (n = 54): log10 3·6(0·2) versus 6·4(0·1) c.f.u./g respectively at 24 h (P &lt; 0·001, Mann–Whitney rank sum test) and log10 4·4(0·2) versus 6·6(0·1) c.f.u./g at 72 h (P &lt; 0·001). At 14 days, E41-Skelite™-treated tibias had fewer bacteria, no signs of osteomyelitis and histological signs of healing.

Conclusion

E41-Skelite™, a prototype granulated topical antibiotic delivery system, reduced the development of infection in experimental bone wounds.

Adaptation of a dental RadioVisioGraph unit as a laboratory animal research tool

We have adapted the RadioVisioGraph (RVG), a digital radiography system designed for dentistry, to become a versatile research tool in a small research facility. We have used this modified digital imaging system in our institution to assess bone fractures and ossification in rabbit tibias in which titanium posts were placed in close proximity to one another, to evaluate bone fill in rats with experimental cranial critical-size defects, and to ensure the proper placement of oral gavage tubes in rodents. This method provides instantaneous digital radiographs, thus not requiring a dedicated X-ray suite or film-processing equipment, and reduces scatter radiation by < or =95%. The use of this technology in a small research facility has greatly improved the quality of both the care our animals receive and the research data we obtain.

Elevated function of blood clotting factor VIIa mutants that have enhanced affinity for membranes. Behavior in a diffusion-limited reaction

Blood clotting factor VIIa is involved in the first step of the blood coagulation cascade, as a membrane-associated enzyme in complex with tissue factor (TF). Factor VIIa is also an important therapeutic agent for hemophilia where its function may include TF-independent as well as TF-dependent mechanisms. This study compared the activity of wild type factor VIIa (WT-VIIa) with that of a mutant with elevated affinity for membrane (P10Q/Q32E, QE-VIIa). Phospholipid and cell-based assays showed the mutant to have up to 40-fold higher function than WT-VIIa in both TF-dependent and TF-independent reactions. Tissue factor-dependent reactions displayed the maximum enhancement when binding had reached equilibrium in competition with another TF-binding protein. In liposome-based assays, the association rate of WT-VIIa with TF occurred at a physical maximum and could not be improved by site-directed mutagenesis. A practical consequence was identical function of WT-VIIa and QE-VIIa in assays that depended entirely on assembly kinetics. Thus, factor VIIa mutants provided unique reagents for probing the mechanism of factor VIIa action. They may also offer superior agents for therapy.

The effect of dental implant spacing on peri-implant bone using the rabbit (Oryctolagus cuniculus) tibia model

PURPOSE

This study investigated the effects of implant proximity on inter-implant bone height, density, and osseointegration using digital radiography and histology.

MATERIALS AND METHODS

After a feasibility study, a total of 80 endosteal implants were placed in 20 New Zealand White Rabbit tibias. With the aid of a surgical jig, four 8.5-mm implants were placed in the medial aspect of the tibial crest at inter-implant distances of approximately 1, 1.5, and 3 mm. Standardized digital radiographs using a paralleling device were made immediately after placement of implants. Implants were allowed to osseointegrate for 90 days. After this healing period, the animals were sacrificed, and the standardized radiographs were repeated. The tibias were harvested, processed, and invested in epoxy. Sagittal sections were made from each specimen for histologic evaluation. The initial and postmortem digital radiographs were evaluated for inter-implant distances, vertical bone height changes over time and between implant pairs, and bone density changes over time and between implant pairs using a computer image analysis program and computer statistics program.

RESULTS

The actual inter-implant distances were consistent in a range of 0.2 mm. Bone height increased significantly from presurgical levels at all 3 locations (p < .0005). Repeated measures analysis of variance comparing change in bone height at the 3 implant pair distances showed significant differences among the 3 (p = .002). Paired t tests showed that the amount of bone growth at the 1-mm separation site was significantly greater than the 1.5-mm site (p = .026) and the 3-mm site (p = .001), whereas bone growth at the 1.5- and 3-mm sites did not show significant differences (p = .162). A repeated measures analysis of variance comparing change in bone density showed no significant differences (p > .05) among the 3 inter-implant distances for either the 8-mm position (approximately crestal bone height) or the 6-mm position (approximately 2 mm subcrestal).

CONCLUSION

Within the limits of this study, it seems placing implants closely together does not adversely affect bone height or density. Conversely, it seems that placing implants closer together may increase bone growth.

Port-site recurrence reproduced in the VX-2 rabbit carcinoma model: an in vivo model comparing laparoscopic port sites and open incisions

BACKGROUND

The use of advanced laparoscopy remains controversial in the field of surgical oncology because the potential for port-site recurrence may violate sound oncologic principles. Two mechanisms are theorized to be the cause of port-site recurrences: first, indirect contamination caused by pneumoperitoneum, aerosolization, or intraperitoneal spread, and second, direct contamination by physical trocar seeding.

METHODS

A VX-2 carcinoma cell suspension was transferred under the left renal capsule of 31 rabbits with either an open flank incision (16) or laparoscopy (15). Animals were observed for tumor recurrence at the video port, the working port, and the open incision. Intraoperative findings and necropsy were used to document recurrence.

RESULTS

The open incision technique resulted in local tumor recurrence in 1/16 animals with 16/16 viable intraabdominal tumors. The laparoscopic technique resulted in 0/15 video port-site recurrences and 9/15 working port-site recurrences, with 14/15 viable intraabdominal tumors. Recurrence at the laparoscopic working port occurred more frequently than in the open (P < 0.02) or laparoscopic video port groups (P < 0.007). No significant difference existed in recurrence between the open incision and the laparoscopic video port (P > 0.5).

CONCLUSIONS

Laparoscopic port-site recurrences can be reproduced using the transplantable VX-2 rabbit carcinoma model. In the VX-2 model, trocar recurrence is the result of direct contamination via surgical instrumentation of viable tumor cells. The effect of the pneumoperitoneum or intraperitoneal cytological spillage (indirect contamination) does not have any effect on trocar recurrence. This model can be used to test and improve laparoscopic techniques to minimize the risk of port-site recurrence. Until technological advances have eliminated the risk of trocar recurrences, direct contact between malignant cells and laparoscopic instruments should be performed with caution.

Prevention of adhesions to polypropylene mesh in a traumatized bowel model

BACKGROUND

Polypropylene mesh (PPM) is an effective material for the repair of abdominal wall defects, but has a tendency to induce dense adhesions when in contact with viscera. Seprafilm (Genzyme Corp, Cambridge, MA), a bioresorbable membrane, has been shown to reduce adhesion formation after midline closures in humans and to PPM in animals. Given the increased inflammatory response expected with surgical trauma, its efficacy under surgical conditions has been questioned.

STUDY DESIGN

A prospective, randomized, blinded study was conducted using a rabbit model. Standardized abdominal wall defects were created in three groups of New Zealand white rabbits. The cecum was deserosalized to simulate the effects of trauma. The abdominal defect was then repaired with PPM. In the control group, no Seprafilm was used. In the first experimental group Seprafilm was placed between the mesh and the abdominal viscera. In the second experimental group Seprafilm was placed over the deserosalized area and between the mesh and abdominal viscera. Animals were sacrificed at 30 days and adhesions were categorized and quantified using digital image analysis of inked specimens. The strength of incorporation was also determined.

RESULTS

The formation of adhesions between the viscera and mesh repair was dramatically reduced in both experimental groups compared with the control group. The incidence of visceral adhesions was reduced by 80% in the single film group (p = 0.0004) and 90% in the double film group (p = 0.00008). The reduction in surface area of adhesions was 96.4% in the single film group (p = 0.000019) and 99.4% in the double film group (p = 0.00002). Omental adhesions were reduced by 30% but this did not achieve statistical significance. Strength of incorporation was not adversely affected in either group.

CONCLUSIONS

Seprafilm is highly effective in preventing adhesions to PPM. This effect was not diminished by the presence of visceral trauma and its resultant inflammatory response. The use of Seprafilm does not adversely affect tissue incorporation. Clinical trials are warranted to determine if the protective effects of Seprafilm demonstrated in this study are applicable in the clinical setting.

Vitamin K-dependent proteins

Vitamin K is required for the synthesis of gamma-carboxyglutamate (Gla) during postribosomal protein modification. Substrates include blood clotting proteins, bone proteins, cell signaling, and receptor proteins. In addition, Gla is a component of short toxin peptides from the marine snail Conus. Studies of structure-function relationships are the most advanced for the blood coagulation proteins. Reviews of vitamin K action and blood coagulation are presented. Special focus is on the structure-function role of Gla in blood coagulation and the impact of this amino acid on enzyme reaction kinetics. This amino acid forms calcium and membrane binding sites for these proteins. Two proposed mechanisms of protein-membrane attachment are reviewed. One involves membrane attachment by protein insertion into the hydrocarbon region of the membrane, while another considers attachment by specific interactions with phospholipid head groups. Membrane attachment generates the potential for several forms of nonclassical enzyme kinetic behaviors, all of which have been observed in vitro. For example, the reaction may be limited by properties of the enzyme active site, a condition that allows use of classic steady-state enzyme kinetic parameters. However, the reaction may be limited by substrate binding to the membrane, by substrate flux through solution, and/or by solvent flow rates across the membrane surface. These states provide special mechanisms that are not anticipated by classical steady-state kinetic derivations. They may be used to regulate coagulation in vivo. Overall, vitamin K research spans the spectrum of biological research and experience. Exciting new ideas and findings continue to emanate from vitamin K-related research.

Measurement of lumbar spinal flexion-extension kinematics from lateral radiographs: simulation of the effects of out-of-plane movement and errors in reference point placement

Flexion-extension of the spine is defined in the sagittal plane, which divides the body into right and left halves, and can be measured from lateral radiographs, including those obtained by videofluoroscopy. The effects of axial rotation and lateral bending, which lead to movement out of the sagittal plane, were investigated by generating a three-dimensional computer model of two adjacent vertebrae and projecting it on to the sagittal plane. The projected model was measured as if it were a radiograph, allowing the effects of out-of-plane movement and errors in reference point placement to be calculated. Reference points were defined as the corners of a quadrilateral which fully enclosed the two-dimensional image of each vertebral body, and their projected locations were randomly displaced by 0.5 mm in order to simulate the measurement process. A combination of lateral bending with 1 degree of flexion can lead to a root mean squared (RMS) variation in the calculated position of the instantaneous centre of rotation (ICR) of 292 mm, reducing to 5 mm for 10 degrees of flexion. When the reference point quadrilaterals were divided into two triangles, the RMS variation in the calculated position of the centroid of one of the triangles was only 0.42 mm under the same conditions, remaining constant over the same flexion range. Similar results were obtained when axial rotation was combined with flexion. The calculated centroid provides a robust reference point for kinematic calculations.

Measurement of lumbar spine flexion-extension using a low-field open-magnet magnetic resonance scanner

RATIONALE AND OBJECTIVES

The authors investigated the feasibility of using a low-field open-magnet magnetic resonance (MR) scanner to acquire functional flexion-extension images for range of motion (ROM) measurements on the lumbar spine.

METHODS

Seventeen healthy subjects with no symptoms of back pain (age range, 22-59 years) were scanned in a low-field open-magnet MR scanner in the flexed, neutral, and extended positions. Each image was downloaded to a computer workstation for subsequent flexion-extension, lordosis, and ROM measurement.

RESULTS

Data from two subjects were not analyzed because their images did not show all the lumbar vertebrae. For the remaining 15, there was a large variation in the magnitude of the ROM values (range, 9 degrees-70 degrees; mean 36.4 degrees, SD 16.5 degrees). However, there was a significant correlation between age and ROM (r = -0.63; P < 0.05).

CONCLUSIONS

The low-field open-magnet MR scanner provides a method for noninvasive imaging of the lumbar spine, allowing the subject freedom of movement in the horizontal plane. This enables functional flexion-extension images of the lumbar spine to be acquired.

Rabbit genital tissue is susceptible to infection by rabbit oral papillomavirus: an animal model for a genital tissue-targeting papillomavirus

Rabbit oral papillomavirus (ROPV) is a mucosatropic papillomavirus which naturally infects oral mucosal sites of domestic rabbits. In this study, we tested the hypothesis that rabbit genital mucosa is also susceptible to ROPV infection by using the athymic mouse xenograft system and adult immunocompetent rabbits. Subrenal xenografts of ROPV-infected rabbit vulvar and penile sheath tissues were strongly positive for ROPV infection by histologic, in situ hybridization, and Southern analyses. Direct inoculation of adult rabbit penises with infectious ROPV produced small raised lesions of approximately 1 by 1 by 1 mm that were ROPV positive by both in situ hybridization and Southern analyses and were also viral capsid antigen positive by immunohistological staining. Infection of rabbit genital tissues with ROPV may be a useful animal model for the study of genital tissue-targeting papillomaviruses.

Comparison of the precision of two vertebral morphometry programs for the lunar EXPERT-XL imaging densitometer

Comparative precision tests of the vertebral height measurement function of the Aberdeen Vertebral Morphometry System (AVMS) software and Lunar EXPERT-XL software were undertaken using four vertebrae from the same lateral spine dual energy X-ray absorptiometry (DXA) image of the same subject (male, 67 years). Two of the vertebrae were abnormal and two were normal. Three observers inexperienced in morphometry and one experienced observer took part in the study. Repeatability was obtained from 10 sequential measurements of the posterior, middle and anterior heights at the same sitting by the same observer. Intraobserver reproducibility compared the means of one set of measurements for all vertebrae with another taken 1 week later. Interobserver reproducibility compared the means of one set of measurements for all vertebrae from an experienced and an inexperienced observer, and from two inexperienced observers. The AVMS software had significantly higher (p < 0.05) repeatability (mean coefficient of variability, CV = 3.5%) than the Lunar software (mean CV = 5%), significantly higher (p < 0.01) intraobserver reproducibility (mean CV = 4.6%) than the Lunar software (mean CV = 8.5%), and significantly higher (p < 0.05) interobserver reproducibility (mean CV = 4.7%) than the Lunar software (mean CV = 7.5%). In conclusion, the new AVMS method possessed higher precision when measuring both abnormal and normal vertebrae and when used by both experienced and inexperienced observers.

Reaction of nitric oxide and its derivatives with sulfites: a possible role in sulfite toxicity

The reaction between sulfites and nitric oxide or proposed carriers of nitric oxide (nitrosylated bovine serum albumin and S-nitrosoglutathione) was investigated as a potential source of the adverse effects of sulfites on biological systems. Rapid reaction occurred between sulfites and all of these reagents. Also, the ability of nitric oxide and these carriers of nitric oxide to inhibit platelet aggregation was reversed by low concentrations of sulfites. Counteraction of nitric oxide's ability to function in cell signaling processes may be a major cause of sulfite toxicity.