Genetic and environmental influences on sleep-wake behaviors in adolescence

Study Objectives

To investigate the influence of genetic and environmental factors on sleep-wake behaviors across adolescence.

Methods

Four hundred and ninety-five participants (aged 9-17; 55% females), including 93 monozygotic and 117 dizygotic twin pairs, and 75 unmatched twins, wore an accelerometry device and completed a sleep diary for 2 weeks.

Results

Individual differences in sleep onset, wake time, and sleep midpoint were influenced by both additive genetic (44%-50% of total variance) and shared environmental (31%-42%) factors, with a predominant genetic influence for sleep duration (62%) and restorative sleep (43%). When stratified into younger (aged 9-14) and older (aged 16-17) subsamples, genetic sources were more prominent in older adolescents. The moderate correlation between sleep duration and midpoint (rP = -.43, rG = .54) was attributable to a common genetic source. Sleep-wake behaviors on school and nonschool nights were correlated (rP = .44-.72) and influenced by the same genetic and unique environmental factors. Genetic sources specific to night-type were also identified, for all behaviors except restorative sleep.

Conclusions

There were strong genetic influences on sleep-wake phenotypes, particularly on sleep timing, in adolescence. Moreover, there may be common genetic influences underlying both sleep and circadian rhythms. The differences in sleep-wake behaviors on school and nonschool nights could be attributable to genetic factors involved in reactivity to environmental context.

Continuity of Genetic Risk for Aggressive Behavior Across the Life-Course

We test whether genetic influences that explain individual differences in aggression in early life also explain individual differences across the life-course. In two cohorts from The Netherlands (N = 13,471) and Australia (N = 5628), polygenic scores (PGSs) were computed based on a genome-wide meta-analysis of childhood/adolescence aggression. In a novel analytic approach, we ran a mixed effects model for each age (Netherlands: 12-70 years, Australia: 16-73 years), with observations at the focus age weighted as 1, and decaying weights for ages further away. We call this approach a 'rolling weights' model. In The Netherlands, the estimated effect of the PGS was relatively similar from age 12 to age 41, and decreased from age 41-70. In Australia, there was a peak in the effect of the PGS around age 40 years. These results are a first indication from a molecular genetics perspective that genetic influences on aggressive behavior that are expressed in childhood continue to play a role later in life.

Suicidal Thoughts and Behaviors and Their Associations With Transitional Life Events in Men and Women: Findings From an International Web-Based Sample

BACKGROUND

Although numerous studies have demonstrated sex differences in the prevalence of suicidal thoughts and behaviors (STB), there is a clear lack of research examining the similarities and differences between men and women in terms of the relationship between STB, transitional life events, and the coping strategies employed after experiencing such events when they are perceived as stressful.

OBJECTIVE

This study aims to examine the differences between men's and women's experiences of STB, sociodemographic predictors of STB, and how coping responses after experiencing a stressful transitional life event predict STB.

METHODS

A web-based self-report survey was used to assess the health and well-being of a voluntary community-based sample of men and women aged 16 years and older, living in Australia, Canada, New Zealand, the United Kingdom, and the United States, who were recruited using web-based social media promotion and snowballing.

RESULTS

In total, 10,765 eligible web-based respondents participated. Compared with men, a significantly greater proportion of women reported STB (P<.001) and endorsed experiencing a transitional life event as stressful (P<.001). However, there were no gender differences in reporting that the transitional life event or events was stressful for those who also reported STB. Significant sociodemographic adjusted risk factors of STB included younger age; identifying as a sexual minority; lower subjective social connectedness; lower subjective intimate bonds; experiencing a stressful transitional life event in the past 12 months; living alone (women only); not being in employment, education, or training (women only); suddenly or unexpectedly losing a job (men only); and experiencing a relationship breakdown (men only). Protective factors included starting a new job, retiring, having a language background other than English, and becoming a parent for the first time (men only). The results relating to coping after experiencing a self-reported stressful transitional life event in the past 12 months found that regardless of sex, respondents who reported STB compared with those who did not were less likely to engage in activities that promote social connections, such as talking about their feelings (P<.001). Coping strategies significantly explained 19.0% of the STB variance for men (F_16,1027=14.64; P<.001) and 22.0% for women (F_16,1977=36.45; P<.001).

CONCLUSIONS

This research highlights multiple risk factors for STB, one of which includes experiencing at least one stressful transitional life event in the past 12 months. When individuals are experiencing such events, support from services and the community alike should consider using sex-specific or targeted strategies, as this research indicates that compared with women, more men do nothing when experiencing stress after a transitional life event and may be waiting until they experience STB to engage with their social networks for support.

Project Synergy: co-designing technology-enabled solutions for Australian mental health services reform

Project Synergy aims to test the potential of new and emerging technologies to enhance the quality of mental health care provided by traditional face-to-face services. Specifically, it seeks to ensure that consumers get the right care, first time (delivery of effective mental health care early in the course of illness). Using co-design with affected individuals, Project Synergy has built, implemented and evaluated an online platform to assist the assessment, feedback, management and monitoring of people with mental disorders. It also promotes the maintenance of wellbeing by collating health and social information from consumers, their supportive others and health professionals. This information is reported back openly to consumers and their service providers to promote genuine collaborative care. The online platform does not provide stand-alone medical or health advice, risk assessment, clinical diagnosis or treatment; instead, it supports users to decide what may be suitable care options. Using an iterative cycle of research and development, the first four studies of Project Synergy (2014-2016) involved the development of different types of online prototypes for young people (i) attending university; (ii) in three disadvantaged communities in New South Wales; (iii) at risk of suicide; and (iv) attending five headspace centres. These contributed valuable information concerning the co-design, build, user testing and evaluation of prototypes, as well as staff experiences during development and service quality improvements following implementation. Through ongoing research and development (2017-2020), these prototypes underpin one online platform that aims to support better multidimensional mental health outcomes for consumers; more efficient, effective and appropriate use of health professional knowledge and clinical skills; and quality improvements in mental health service delivery.

Gambling and the Role of Resilience in an International Online Sample of Current and Ex-serving Military Personnel as Compared to the General Population

Compared to the general population, military personnel are particularly vulnerable to developing gambling problems. The present study examined the presentation of gambling-including gambling frequency, personal thoughts on reducing gambling and recommendations from others to reduce gambling-across these populations. Additionally, the study measured the association between gambling and various psychosocial risk and protective factors-including psychological distress, suicidal ideation, external encouragement to reduce substance use, days out of role, personal wellbeing, resilience, social support and intimate bonds. Data was extracted from the Global Health & Wellbeing Survey, an online self-report survey conducted in Australia, Canada, New Zealand, the United Kingdom and the United States. Of the 10,765 eligible respondents, 394 were military veterans and 337 were active military personnel. Consistent with previous research, a higher proportion of gambling behaviours were observed in both current and ex-serving military samples, compared to the general population. To varying degrees, significant associations were found between the different gambling items and all psychosocial risk and protective factors in the general population sample. However, the military sample yielded only one significant association between gambling frequency and the protective factor 'resilience'. A post hoc stepwise linear regression analysis demonstrated the possible mediating role resilience plays between gambling frequency and other psychosocial risk (psychological distress, and suicidal thoughts and behaviour) and protective factors (personal wellbeing) for the military sample. Given the findings, it is recommended that routine screening tools identifying problem gambling are used within the military, and subsequent resilience focused interventions are offered to at risk personnel.

Sexting, Web-Based Risks, and Safety in Two Representative National Samples of Young Australians: Prevalence, Perspectives, and Predictors

BACKGROUND

The rapid uptake of information and communication technology (ICT) over the past decade-particularly the smartphone-has coincided with large increases in sexting. All previous Australian studies examining the prevalence of sexting activities in young people have relied on convenience or self-selected samples. Concurrently, there have been recent calls to undertake more in-depth research on the relationship between mental health problems, suicidal thoughts and behaviors, and sexting. How sexters (including those who receive, send, and two-way sext) and nonsexters apply ICT safety skills warrants further research.

OBJECTIVE

This study aimed to extend the Australian sexting literature by measuring (1) changes in the frequency of young people's sexting activities from 2012 to 2014; (2) young people's beliefs about sexting; (3) association of demographics, mental health and well-being items, and internet use with sexting; and (4) the relationship between sexting and ICT safety skills.

METHODS

Computer-assisted telephone interviewing using random digit dialing was used in two Young and Well National Surveys conducted in 2012 and 2014. The participants included representative and random samples of 1400 young people aged 16 to 25 years.

RESULTS

From 2012 to 2014, two-way sexting (2012: 521/1369, 38.06%; 2014: 591/1400, 42.21%; P=.03) and receiving sexts (2012: 375/1369, 27.39%; 2014: 433/1400, 30.93%; P<.001) increased significantly, not sexting (2012: 438/1369, 31.99%; 2014: 356/1400, 25.43%; P<.001) reduced significantly, whereas sending sexts (2012: n=35/1369, 2.56%; 2014: n=20/1400, 1.43%; P>.05) did not significantly change. In addition, two-way sexting and sending sexts were found to be associated with demographics (male, second language, and being in a relationship), mental health and well-being items (suicidal thoughts and behaviors and body image concerns), and ICT risks (cyberbullying others and late-night internet use). Receiving sexts was significantly associated with demographics (being male and not living with parents or guardians) and ICT risks (being cyberbullied and late-night internet use). Contrary to nonsexters, Pearson correlations demonstrated that all sexting groups (two-way, sending, and receiving) had a negative relationship with endorsing the ICT safety items relating to being careful when using the Web and not giving out personal details.

CONCLUSIONS

Our research demonstrates that most young Australians are sexting or exposed to sexting in some capacity. Sexting is associated with some negative health and well-being outcomes-specifically, sending sexts is linked to suicidal thoughts and behaviors, body image issues, and ICT safety risks, including cyberbullying and late-night internet use. Those who do sext are less likely to engage in many preventative ICT safety behaviors. How the community works in partnership with young people to address this needs to be a multifaceted approach, where sexting is positioned within a wider proactive conversation about gender, culture, psychosocial health, and respecting and caring for each other when on the Web.

Nineteen and Up study (19Up): understanding pathways to mental health disorders in young Australian twins

PURPOSE

The Nineteen and Up study (19Up) assessed a range of mental health and behavioural problems and associated risk factors in a genetically informative Australian cohort of young adult twins and their non-twin siblings. As such, 19Up enables detailed investigation of genetic and environmental pathways to mental illness and substance misuse within the Brisbane Longitudinal Twin Sample (BLTS).

PARTICIPANTS

Twins and their non-twin siblings from Queensland, Australia; mostly from European ancestry. Data were collected between 2009 and 2016 on 2773 participants (age range 18-38, 57.8% female, 372 complete monozygotic pairs, 493 dizygotic pairs, 640 non-twin siblings, 403 singleton twins).

FINDINGS TO DATE

A structured clinical assessment (Composite International Diagnostic Interview) was used to collect lifetime prevalence of diagnostic statistical manual (4th edition) (DSM-IV) diagnoses of major depressive disorder, (hypo)mania, social anxiety, cannabis use disorder, alcohol use disorder, panic disorder and psychotic symptoms. Here, we further describe the comorbidities and ages of onset for these mental disorders. Notably, two-thirds of the sample reported one or more lifetime mental disorder.In addition, the 19Up study assessed general health, drug use, work activity, education level, personality, migraine/headaches, suicidal thoughts, attention deficit hyperactivity disorder (ADHD) symptomatology, sleep-wake patterns, romantic preferences, friendships, familial environment, stress, anorexia and bulimia as well as baldness, acne, asthma, endometriosis, joint flexibility and internet use.The overlap with previous waves of the BLTS means that 84% of the 19Up participants are genotyped, 36% imaged using multimodal MRI and most have been assessed for psychological symptoms at up to four time points. Furthermore, IQ is available for 57%, parental report of ADHD symptomatology for 100% and electroencephalography for 30%.

FUTURE PLANS

The 19Up study complements a phenotypically rich, longitudinal collection of environmental and psychological risk factors. Future publications will explore hypotheses related to disease onset and development across the waves of the cohort. A follow-up study at 25+years is ongoing.

Abstract P6-12-11: Feasibility and biomarker modulation due to high levels of moderate to vigorous physical activity as part of a weight loss intervention in older, sedentary, obese breast cancer survivors

We sought to demonstrate that older, sedentary, obese breast cancer survivors could achieve &gt; 200 minutes per week of moderate to vigorous physical activity (MVI PA) as part of a weight loss intervention; and to assess modulation of risk biomarkers. This level of PA in combination with moderate calorie restriction is associated with weight losses of &gt;10% in women without cancer, which in turn is associated with significant modulation of cancer risk biomarkers.

Eleven participants with BMI &gt; 30 kg/m2 enrolled in a 12-week program that consisted of moderate caloric restriction, weekly phone group behavioral sessions, and individualized exercise plans based on measured heart rate reserve. Women were provided an accelerometer with heart rate monitor linked to GarminConnect, membership to a YMCA, twice weekly supervised exercise sessions with a personal trainer, and weekly feedback regarding weight and physical activity progress. The goal was to increase MVI PA (≥45% heart rate reserve) gradually from &lt;60 to &gt;200 minutes per week.

The median age was 61, 5/11 women had received prior chemotherapy, and 7/11 were currently taking aromatase inhibitors. Median values of baseline anthropomorphic measures acquired by dual energy x-ray absorptiometry (GE Lunar iDXA) included BMI, 37.3 kg/m2; total mass, 97.5 kg; fat mass, 47.6 kg; visceral fat, 1.7 kg (range 1.4-3.0); and fat mass index, 17.6 kg/m2. The majority had a baseline VO2 peak in the poor range for their age. All 11 participants completed the intervention, with no reported serious adverse events. Median MVI PA achieved over weeks 5-12 was 161 minutes/week (range 48-320). VO2 peak was increased in 10/11 with a median relative change of 12% from baseline. All but one lost weight with an overall median of 8% total mass loss, which was associated with 13% total fat mass loss and 21% visceral fat mass loss. For those with MVI PA above the median, values were 11%, 17%, and 40%, respectively. Visceral fat mass loss was linearly correlated with minutes per week of MVI PA (p=0.032); these parameters in turn were associated with changes in a number of serum biomarkers, including adiponectin-leptin ratio, TNF-alpha, as well as circulating adipose stromal cells, a potential marker for metastasis. Insulin and hs-CRP were favorably modulated in almost all participants but change was not linearly correlated with activity or mass loss parameters; thus these may not be ideal biomarkers to document a dose response to level of MVI PA.

Conclusion: These results demonstrate that older, sedentary, obese breast cancer survivors can safely achieve a high level of MVI PA when provided a structured program that includes an exercise trainer. It is feasible to design a clinical trial for such breast cancer survivors to examine biomarker modulation as a function of level of physical activity.

Citation Format: Fabian CJ, Klemp JR, Burns JM, Vidoni ED, Nydegger JL, Kreutzjans AL, Phillips TL, Baker HA, Hendry B, John C, Amin AL, Khan QJ, Mitchell MP, O'Dea AP, Sharma P, Wagner JL, Hursting SD, Kimler BF. Feasibility and biomarker modulation due to high levels of moderate to vigorous physical activity as part of a weight loss intervention in older, sedentary, obese breast cancer survivors [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-12-11.

Comparison of Self-Reported Telephone Interviewing and Web-Based Survey Responses: Findings From the Second Australian Young and Well National Survey

BACKGROUND

Web-based self-report surveying has increased in popularity, as it can rapidly yield large samples at a low cost. Despite this increase in popularity, in the area of youth mental health, there is a distinct lack of research comparing the results of Web-based self-report surveys with the more traditional and widely accepted computer-assisted telephone interviewing (CATI).

OBJECTIVE

The Second Australian Young and Well National Survey 2014 sought to compare differences in respondent response patterns using matched items on CATI versus a Web-based self-report survey. The aim of this study was to examine whether responses varied as a result of item sensitivity, that is, the item's susceptibility to exaggeration on underreporting and to assess whether certain subgroups demonstrated this effect to a greater extent.

METHODS

A subsample of young people aged 16 to 25 years (N=101), recruited through the Second Australian Young and Well National Survey 2014, completed the identical items on two occasions: via CATI and via Web-based self-report survey. Respondents also rated perceived item sensitivity.

RESULTS

When comparing CATI with the Web-based self-report survey, a Wilcoxon signed-rank analysis showed that respondents answered 14 of the 42 matched items in a significantly different way. Significant variation in responses (CATI vs Web-based) was more frequent if the item was also rated by the respondents as highly sensitive in nature. Specifically, 63% (5/8) of the high sensitivity items, 43% (3/7) of the neutral sensitivity items, and 0% (0/4) of the low sensitivity items were answered in a significantly different manner by respondents when comparing their matched CATI and Web-based question responses. The items that were perceived as highly sensitive by respondents and demonstrated response variability included the following: sexting activities, body image concerns, experience of diagnosis, and suicidal ideation. For high sensitivity items, a regression analysis showed respondents who were male (beta=-.19, P=.048) or who were not in employment, education, or training (NEET; beta=-.32, P=.001) were significantly more likely to provide different responses on matched items when responding in the CATI as compared with the Web-based self-report survey. The Web-based self-report survey, however, demonstrated some evidence of avidity and attrition bias.

CONCLUSIONS

Compared with CATI, Web-based self-report surveys are highly cost-effective and had higher rates of self-disclosure on sensitive items, particularly for respondents who identify as male and NEET. A drawback to Web-based surveying methodologies, however, includes the limited control over avidity bias and the greater incidence of attrition bias. These findings have important implications for further development of survey methods in the area of health and well-being, especially when considering research topics (in this case diagnosis, suicidal ideation, sexting, and body image) and groups that are being recruited (young people, males, and NEET).

The role of technology in Australian youth mental health reform

This paper describes the extent and nature of Internet use by young people, with specific reference to psychological distress and help-seeking behaviour. It draws on data from an Australian cross-sectional study of 1400 young people aged 16 to 25 years. Nearly all of these young people used the Internet, both as a source of trusted information and as a means of connecting with their peers and discussing problems. A new model of e-mental health care is introduced that is directly informed by these findings. The model creates a system of mental health service delivery spanning the spectrum from general health and wellbeing (including mental health) promotion and prevention to recovery. It is designed to promote health and wellbeing and to complement face-to-face services to enhance clinical care. The model has the potential to improve reach and access to quality mental health care for young people, so that they can receive the right care, at the right time, in the right way. What is known about the topic? One in four young Australians experience mental health disorders, and these often emerge in adolescence and young adulthood. Young people are also prominent users of technology and the Internet. Effective mental health reform must recognise the opportunities that technology affords and leverage this medium to provide services to improve outcomes for young people. What does this paper add? Information regarding the nature of young people’s Internet use is deficient. This paper presents the findings of a national survey of 1400 young Australians to support the case for the role of technology in Australian mental health reform. What are the implications for practitioners? The Internet provides a way to engage young people and provide access to mental health services and resources to reduce traditional barriers to help-seeking and care. eMental health reform can be improved by greater attention toward the role of technology and its benefits for mental health outcomes.

The Use of Donation After Cardiac Death Allografts Does Not Increase Recurrence of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) recurrence in patients undergoing liver transplantation (LT) with donation after brain death (DBD) and donation after cardiac death (DCD) allografts has not previously been investigated. Rates and patterns of HCC recurrences were investigated in patients undergoing DBD (N = 1633) and DCD (N = 243) LT between 2003 and 2012. LT for HCC was identified in 397 patients (340 DBD and 57 DCD). No difference in tumor number (p = 0.26), tumor volume (p = 0.34) and serum alphafetoprotein (AFP) (p = 0.47) was seen between the groups. HCC recurrence was identified in 41 (12.1%) patients in the DBD group and 7 (12.3%) patients in the DCD group. There was no difference in recurrence-free survival (p = 0.29) or cumulative incidence of HCC recurrence (p = 0.91) between the groups. Liver allograft was the first site of recurrence in 22 (65%) patients in the DBD group and two (37%) patients in the DCD group (p = 0.39). LT for HCC with DBD and DCD allografts demonstrate no difference in the rate of HCC recurrence. Previously published differences in survival demonstrated between recipients with HCC receiving DBD and DCD allografts despite statistical adjustment can likely be explained by practice patterns not captured by variables contained in the SRTR database.

Preparing Muscles for Diving: Age-Related Changes in Muscle Metabolic Profiles in Harp (Pagophilus groenlandicus) and Hooded (Cystophora cristata) Seals

In adult marine mammals, muscles can sustain aerobic metabolism during dives in part because they contain large oxygen (O2) stores and metabolic rates are low. However, young pups have significantly lower tissue O2 stores and much higher mass-specific metabolic rates. To investigate how these differences may influence muscle function during dives, we measured the activities of enzymes involved in aerobic and anaerobic metabolic pathways (citrate synthase [CS], β-hydroxyacyl-coenzyme A dehydrogenase [HOAD], lactate dehydrogenase [LDH]) and the LDH isoform profile in six muscles from 41 harp (Pagophilus groenlandicus) and 30 hooded (Cystophora cristata) seals ranging in age from fetal to adult. All neonatal muscles had significantly higher absolute but lower metabolically scaled CS and HOAD activities than adults (∼ 70% and ∼ 85% lower, respectively). Developmental increases in LDH activity lagged that of aerobic enzymes and were not accompanied by changes in isozyme profile, suggesting that changes in enzyme concentration rather than structure determine activity levels. Biochemical maturation proceeded faster in the major locomotory muscles. In combination, findings suggest that pup muscles are unable to support strenuous aerobic exercise or rely heavily on anaerobic metabolism during early diving activities and that pups' high mass-specific metabolic rates may play a key role in limiting the ability of their muscles to support underwater foraging.

Insulin resistance and gray matter volume in neurodegenerative disease

The goal of this study was to compare insulin resistance in aging and aging-related neurodegenerative diseases, and to determine the relationship between insulin resistance and gray matter volume (GMV) in each cohort using an unbiased, voxel-based approach. Insulin resistance was estimated in apparently healthy elderly control (HC, n=21) and neurodegenerative disease (Alzheimer's disease (AD), n=20; Parkinson's disease (PD), n=22) groups using Homeostasis Model Assessment of Insulin Resistance 2 (HOMA2) and intravenous glucose tolerance test (IVGTT). HOMA2 and GMV were assessed within groups through General Linear Model multiple regression. We found that HOMA2 was increased in both AD and PD compared to the HC group (HC vs. AD, p=0.002, HC vs. PD, p=0.003), although only AD subjects exhibited increased fasting glucose (p=0.005). Furthermore, our voxel-based morphometry analysis revealed that HOMA2 was related to GMV in all cohorts in a region-specific manner (p<0.001, uncorrected). Significant relationships were observed in the medial prefrontal cortex (HC), medial temporal regions (AD), and parietal regions (PD). Finally, the directionality of the relationship between HOMA2 and GMV was disease-specific. Both HC and AD subjects exhibited negative relationships between HOMA2 and brain volume (increased HOMA2 associated with decreased brain volume), while a positive relationship was observed in PD. This cross-sectional study suggests that insulin resistance is increased in neurodegenerative disease, and that individuals with AD appear to have more severe metabolic dysfunction than individuals with PD or PD dementia.

Young men's attitudes and behaviour in relation to mental health and technology: implications for the development of online mental health services

BACKGROUND

This mixed-methods study was designed to explore young Australian men's attitudes and behaviour in relation to mental health and technology use to inform the development of online mental health services for young men.

METHODS

National online survey of 486 males (aged 16 to 24) and 17 focus groups involving 118 males (aged 16 to 24).

RESULTS

Young men are heavy users of technology, particularly when it comes to entertainment and connecting with friends, but they are also using technology for finding information and support. The focus group data suggested that young men would be less likely to seek professional help for themselves, citing a preference for self-help and action-oriented strategies instead. Most survey participants reported that they have sought help for a problem online and were satisfied with the help they received. Focus group participants identified potential strategies for how technology could be used to overcome the barriers to help-seeking for young men.

CONCLUSIONS

The key challenge for online mental health services is to design interventions specifically for young men that are action-based, focus on shifting behaviour and stigma, and are not simply about increasing mental health knowledge. Furthermore, such interventions should be user-driven, informed by young men's views and everyday technology practices, and leverage the influence of peers.

Young men, mental health, and technology: implications for service design and delivery in the digital age

Background

Young men are particularly vulnerable to suicide, drug, and alcohol problems and yet fail to seek appropriate help. An alternative or adjunct to face-to-face services has emerged with widespread uptake of the Internet and related communication technologies, yet very little evidence exists that examines the capacity of the Internet to engage young men and promote help seeking.

Objective

To explore young people’s attitudes and behaviors in relation to mental health and technology use. The aim was to identify key gender differences to inform the development of online mental health interventions for young men.

Methods

A cross-sectional online survey of 1038 young people (aged 16 to 24 years) was used.

Results

Young men are more likely than young women to play computer games, access online video/music content, and visit online forums. More than half of young men and women reported that they sought help for a problem online, and the majority were satisfied with the help they received. Significant gender differences were identified in relation to how young people would respond to a friend in need, with young men being less likely than young women to confront the issue directly.

Conclusions

Online interventions for young men need to be action-oriented, informed by young men’s views and everyday technology practices, and leverage the important role that peers play in the help-seeking process.

Alzheimer disease biomarkers are associated with body mass index

OBJECTIVE

Both low and high body mass index (BMI) has been associated with cognitive impairment and dementia risk, including Alzheimer disease (AD). We examined the relationship of BMI with potential underlying biological substrates for cognitive impairment.

METHODS

We analyzed cross-sectional data from participants enrolled in the Alzheimer's Disease Neuroimaging Initiative (ADNI) with PET imaging using Pittsburgh Compound B (PiB, n = 101) or CSF analyses (n = 405) for β-amyloid peptide (Aβ) and total tau. We assessed the relationship of CSF biomarkers and global PiB uptake with BMI using linear regression controlling for age and sex. We also assessed BMI differences between those who were and were not considered biomarker positive. Finally, we assessed BMI change over 2 years in relationship to AD biomarkers.

RESULTS

No dementia, mild cognitive impairment (MCI), and AD groups were not different in age, education, or BMI. In the overall sample, CSF Aβ (β = 0.181, p < 0.001), tau (β = -0.179, p < 0.001), tau/Aβ ratio (β = -0.180, p < 0.001), and global PiB uptake (β = -0.272, p = 0.005) were associated with BMI, with markers of increased AD burden associated with lower BMI. Fewer overweight individuals had biomarker levels indicative of pathophysiology (p < 0.01). These relationships were strongest in the MCI and no dementia groups.

CONCLUSIONS

The presence and burden of in vivo biomarkers of cerebral amyloid and tau are associated with lower BMI in cognitively normal and MCI individuals. This supports previous findings of systemic change in the earliest phases of the disease. Further, MCI in those who are overweight may be more likely to result from heterogeneous pathophysiology.

Signalling through the IL-2 receptor γ(c) peptide (CD132) is essential for the expression of immunity to Plasmodium chabaudi adami blood-stage malaria

A genetic dissection approach was employed to determine whether the IL-2 receptor complex (IL-2R) comprised of α, β and γ chains is required for the suppression of Plasmodium chabaudi adami parasitemia. Blood-stage infections in IL-2Rγ(c)(-/y) mice failed to cure with parasitemia remaining elevated for > 50 days indicating the IL-2Rγ(c) through which all members of the γ(c) family of cytokines signal has an essential role in protective immunity against blood-stage malarial parasites. In contrast, the curing of parasitemia in IL-2/15Rβ⁻/⁻ mice, deficient in both IL-2 and IL-15 signalling was significantly delayed but did occur, indicating that neither cytokine plays an essential role in parasite clearance. Moreover, the observation that the time course of parasitemia in IL-15⁻/⁻ mice was nearly identical to that seen in controls suggests that the parasitemia-suppressing role of stimulating through the IL-2/15Rβ chain is owing to IL-2 signalling and not a redundant function of IL-15.

The internet as a setting for mental health service utilisation by young people

OBJECTIVE

To explore patterns of internet use by young people in Australia and assess the usefulness of online resources for mental health problems, exploring functionality that may be relevant in the development of online mental health services.

DESIGN AND PARTICIPANTS

Cross-sectional survey of a nationally representative sample of young people (2000 randomly selected participants aged 12-25 years), via telephone interview, conducted in January-March 2008.

MAIN OUTCOME MEASURES

Patterns of internet use including type of use, social networking, sources of information about mental health, alcohol or other substance use problems and levels of satisfaction with the information, and type of information accessed via websites.

RESULTS

Young people reported using the internet to connect with other young people (76.9%; 1464/1905) and to seek information about a mental health problem, regardless of whether they had a problem themselves (38.8%; 735/1894). Twenty per cent of young people (398/1990) had personally experienced a mental health problem in the previous 5 years; when these people were asked about sources of information used for this problem, 30.8% (70/227) reported searching the internet. Patterns of internet use and types of resources used differed by age and sex.

CONCLUSION

Our findings suggest that technology is important in the everyday lives of young people, and online mental health services that encompass promotion and prevention activities should include a variety of resources that appeal to all ages and both sexes, such as "question and answer" forums and email.

Reach Out Central: a serious game designed to engage young men to improve mental health and wellbeing

Reach Out Central (ROC) is a serious game drawing on the principles of cognitive behaviour theory that has been designed to improve the mental health and wellbeing of young people, particularly men. ROC was developed over a 3-year period from 2003 to 2006, in consultation with young people aged 16-25 years who use the Reach Out mental health website http://www.reachout.com). ROC was launched online in September 2007. A traditional and viral awareness campaign was designed to engage young men, particularly "gamers". In the first month after launch, ROC had 76 045 unique website visits, with 10 542 new members (52% male) joining Reach Out. An independent online evaluation involving 266 young people aged 18-25 years was conducted between August 2007 and February 2008 to examine psychological wellbeing, stigma and help seeking in ROC players. Overall results indicated that ROC was successful in attracting, engaging and educating young people. Young women reported reduced psychological distress and improved life satisfaction, problem solving and help seeking; however, no significant changes were observed for young men. Although ROC was successful in attracting young men, demonstrating that the concept resonates with them, the service failed to keep them engaged. Further research is needed to explore how (or what changes need to be made) to sustain young men's engagement in the game.

Preferential Mating versus Mimicry: Disruptive Selection and Sex-limited Dimorphism in Papilio glaucus

Spermatophore counts in wild females of Papilio glaucus show that the monomorphic nonmimetic male mates less frequently with the mimetic female morph than with the nonmimetic female morph. Female dimorphism in this species cannot be maintained by heterozygous advantage. Mating preference for the nonmimetic female may sufficiently counteract avian predation pressure favoring the mimetic female to account for the maintenance of the nonmimetic morph in the population in those areas in which the model is abundant and to account for the reduction in frequency or elimination of the mimetic morph in those areas in which the model is less numerous or absent.

Development of aerobic and anaerobic metabolism in cardiac and skeletal muscles from harp and hooded seals

In diving animals, skeletal muscle adaptations to extend underwater time despite selective vasoconstriction include elevated myoglobin (Mb) concentrations, high acid buffering ability (beta) and high aerobic and anaerobic enzyme activities. However, because cardiac muscle is perfused during dives, it may rely less heavily on Mb, beta and anaerobic pathways to support contractile activity. In addition, because cardiac tissue must sustain contractile activity even before birth, it may be more physiologically mature at birth and/or develop faster than skeletal muscles. To test these hypotheses, we measured Mb levels, beta and the activities of citrate synthase (CS), beta-hydroxyacyl-CoA dehydrogenase (HOAD) and lactate dehydrogenase (LDH) in cardiac and skeletal muscle samples from 72 harp and hooded seals, ranging in age from fetuses to adults. Results indicate that in adults cardiac muscle had lower Mb levels (14.7%), beta (55.5%) and LDH activity (36.2%) but higher CS (459.6%) and HOAD (371.3%) activities (all P<0.05) than skeletal muscle. In addition, while the cardiac muscle of young seals had significantly lower [Mb] (44.7%) beta (80.7%) and LDH activity (89.5%) than adults (all P<0.05), it was relatively more mature at birth and weaning than skeletal muscle. These patterns are similar to those in terrestrial species, suggesting that seal hearts do not exhibit unique adaptations to the challenges of an aquatic existence.

Reduced gray matter volume in normal adults with a maternal family history of Alzheimer disease

OBJECTIVE

A consistently identified risk factor for Alzheimer disease (AD) is family history of dementia, with maternal transmission significantly more frequent than paternal transmission. A history of maternal AD may be related to AD-like glucose consumption in cognitively healthy subjects. In this cross-sectional study, we tested whether cognitively healthy people with a family history of AD have less gray matter volume (GMV), an endophenotype for late-onset AD, than individuals with no family history, and whether decreases in GMV are different in subjects with a maternal family history.

METHODS

As part of the Kansas University Brain Aging Project, 67 cognitively intact individuals with a maternal history of late-onset AD (FHm, n = 16), a paternal history of AD (FHp, n = 8), or no parental history of AD (FH-, n = 43), similar in age, gender, education, and Mini-Mental State Examination score, were scanned at 3 T. We used voxel-based morphometry to examine GMV differences between groups, controlling for age, gender, and apoE4.

RESULTS

Cognitively healthy individuals with a family history of late-onset AD had significantly decreased GMV in the precuneus, middle frontal, inferior frontal, and superior frontal gyri compared with FH- individuals. FHm subjects had significantly smaller inferior frontal, middle frontal, precuneus, and lingual gyri compared with FH- and FHp subjects.

CONCLUSIONS

Overall, maternal family history of Alzheimer disease (AD) in cognitively normal individuals is associated with lower gray matter volume in AD-vulnerable brain regions. These data complement and extend reports of cerebral metabolic differences in subjects with a maternal family history.

Postnatal development of muscle biochemistry in nursing harbor seal (Phoca vitulina) pups: limitations to diving behavior?

Adult marine mammal muscles rely upon a suite of adaptations for sustained aerobic metabolism in the absence of freely available oxygen (O(2)). Although the importance of these adaptations for supporting aerobic diving patterns of adults is well understood, little is known about postnatal muscle development in young marine mammals. However, the typical pattern of vertebrate muscle development, and reduced tissue O(2) stores and diving ability of young marine mammals suggest that the physiological properties of harbor seal (Phoca vitulina) pup muscle will differ from those of adults. We examined myoglobin (Mb) concentration, and the activities of citrate synthase (CS), beta-hydroxyacyl coA dehydrogenase (HOAD), and lactate dehydrogenase (LDH) in muscle biopsies from harbor seal pups throughout the nursing period, and compared these biochemical parameters to those of adults. Pups had reduced O(2) carrying capacity ([Mb] 28-41% lower than adults) and reduced metabolically scaled catabolic enzyme activities (LDH/RMR 20-58% and CS/RMR 29-89% lower than adults), indicating that harbor seal pup muscles are biochemically immature at birth and weaning. This suggests that pup muscles do not have the ability to support either the aerobic or anaerobic performance of adult seals. This immaturity may contribute to the lower diving capacity and behavior in younger pups. In addition, the trends in myoglobin concentration and enzyme activity seen in this study appear to be developmental and/or exercise-driven responses that together work to produce the hypoxic endurance phenotype seen in adults, rather than allometric effects due to body size.

Mental health of young people in the United States: what role can the internet play in reducing stigma and promoting help seeking?

One third of young Americans experience mental health difficulties, often without seeking help. More than 90% use the Internet. Reach Out (www.reachout.com.au), an Australian Internet-based service, is discussed in relation to the role it could play in reducing stigma and increasing help seeking in young Americans aged 16-25 years.

Development of myoglobin concentration and acid buffering capacity in harp (Pagophilus groenlandicus) and hooded (Cystophora cristata) seals from birth to maturity

Pinnipeds rely on muscle oxygen stores to help support aerobic diving, therefore muscle maturation may influence the behavioral ecology of young pinnipeds. To investigate the pattern of muscle development, myoglobin concentration ([Mb]) and acid buffering ability (beta) was measured in ten muscles from 23 harp and 40 hooded seals of various ages. Adult [Mb] ranged from 28-97 to 35-104 mg g tissue(-1) in harp and hooded seals, respectively, with values increasing from the cervical, non-swimming muscles to the main swimming muscles of the lumbar region. Neonatal and weaned pup muscles exhibited lower (approximately 30% adult values) and less variable [Mb] across the body than adults. In contrast, adult beta showed little regional variation (60-90 slykes), while high pup values (approximately 75% adult values) indicate significant in utero development. These findings suggest that intra-uterine conditions are sufficiently hypoxic to stimulate prenatal beta development, but that [Mb] development requires additional postnatal signal such as exercise, and/or growth factors. However, because of limited development in both beta and [Mb] during the nursing period, pups are weaned with muscles with lower aerobic and anaerobic capacities than those of adults.

Proteasome inhibition causes apoptosis of normal human plasma cells preventing alloantibody production

Antibody production by normal plasma cells (PCs) against human leukocyte antigens (HLA) can be a major barrier to successful transplantation. We tested four reagents with possible activity against PCs (rituximab, polyclonal rabbit antithymocyte globulin (rATG), intravenous immunoglobulin (IVIG) and the proteasome inhibitor, bortezomib) to determine their ability to cause apoptosis of human bone marrow-derived PCs and subsequently block IgG secretion in vitro. IVIG, rituximab and rATG all failed to cause apoptosis of PCs and neither rituximab nor rATG blocked antibody production. In contrast, bortezomib treatment led to PC apoptosis and thereby blocked anti-HLA and antitetanus IgG secretion in vitro. Two patients treated with bortezomib for humoral rejection after allogeneic kidney transplantation demonstrated a transient decrease in bone marrow PCs in vivo and persistent alterations in alloantibody specificities. Total IgG levels were unchanged. We conclude that proteasome activity is important for PC longevity and its inhibition may lead to new techniques of controlling antibody production in vivo.

Alloantibody levels and acute humoral rejection early after positive crossmatch kidney transplantation

We examined the course of donor-specific alloantibody (DSA) levels early after transplant and their relationship with acute humoral rejection (AHR) in two groups of positive crossmatch (+XM) kidney transplant recipients: High DSA group-41 recipients with a baseline T- or B-cell flow crossmatch (TFXM, BFXM) channel shift >or=300 (molecules of equivalent soluble fluorochrome units (MESF) of approximately 19 300) who underwent pretransplant plasmapheresis (PP), and Low DSA group-29 recipients with a baseline channel shift <300 who did not undergo PP. The incidence of AHR was 39% (16/41) in the High DSA group and 31% (9/29) in the Low DSA group. Overall, mean DSA levels decreased by day 4 posttransplant and remained low in patients who did not develop AHR. By day 10, DSA levels increased in patients developing AHR with 92% (23/25) of patients with a BFXM >359 (MESF of approximately 34 000) developing AHR. The BFXM and the total DSA measured by single antigen beads correlated well across a wide spectrum suggesting that either could be used for monitoring. We conclude that AHR is associated with the development of High DSA levels posttransplant and protocols aimed at maintaining DSA at lower levels may decrease the incidence of AHR.

Cardiorespiratory fitness and brain atrophy in early Alzheimer disease

OBJECTIVE

To examine the correlation of cardiorespiratory fitness with brain atrophy and cognition in early-stage Alzheimer disease (AD).

BACKGROUND

In normal aging physical fitness appears to mitigate functional and structural age-related brain changes. Whether this is observed in AD is not known.

METHODS

Subjects without dementia (n = 64) and subjects with early-stage AD (n = 57) had MRI and standard clinical and psychometric evaluations. Peak oxygen consumption (VO(2)(peak)), the standard measure of cardiorespiratory fitness, was assessed during a graded treadmill test. Normalized whole brain volume, a brain atrophy estimate, was determined by MRI. Pearson correlation and linear regression were used to assess fitness in relation to brain volume and cognitive performance.

RESULTS

Cardiorespiratory fitness (VO(2)(peak)) was modestly reduced in subjects with AD (34.7 [5.0] mL/kg/min) vs subjects without dementia (38.1 [6.3] mL/kg/min, p = 0.002). In early AD, VO(2)(peak) was associated with whole brain volume (beta = 0.35, p = 0.02) and white matter volume (beta = 0.35, p = 0.04) after controlling for age. Controlling for additional covariates of sex, dementia severity, physical activity, and physical frailty did not attenuate the relationships. VO(2)(peak) was associated with performance on delayed memory and digit symbol in early AD but not after controlling for age. In participants with no dementia, there was no relationship between fitness and brain atrophy. Fitness in participants with no dementia was associated with better global cognitive performance (r = 0.30, p = 0.02) and performance on Trailmaking A and B, Stroop, and delayed logical memory but not after controlling for age.

CONCLUSIONS

Increased cardiorespiratory fitness is associated with reduced brain atrophy in Alzheimer disease (AD). Cardiorespiratory fitness may moderate AD-related brain atrophy or a common underlying AD-related process may impact both brain atrophy and cardiorespiratory fitness.

Two novel assays of alloantibody-secreting cells demonstrating resistance to desensitization with IVIG and rATG

Donor-specific alloantibody presents a major barrier to the successful transplantation of kidneys and hearts. However, the study of alloantibody production has been hampered by both an inadequate source of antibody-secreting cells (ASCs) and a paucity of assays to determine their function. We describe two new assays that allow for the determination of the frequency and specificities of allo-ASCs in humans using purified HLA as targets. These assays demonstrated allo-ASCs in the CD138(+) fraction of the bone marrow, but not in peripheral blood. Alloantibody specificities in these assays correlated well with those detected in the serum suggesting that bone marrow-derived ASCs are indeed a major source of alloantibody in vivo. However, ASCs for a specific HLA antigen were rare with an estimated frequency of only 1/2 x 10(6) marrow cells. Pretransplant treatment in vivo with multiple plasmaphereses and low-dose IVIG alone or in combination with rATG had no effect on ASC number or alloantibody production. These techniques allow for the study of allospecific ASCs and provide a method to test the potential efficacy of agents on alloantibody production in vivo.

Perspectives of young people on depression: awareness, experiences, attitudes and treatment preferences

AIM

Ascertaining current knowledge and attitudes towards depression among young people is vital for developing campaigns promoting community awareness and early intervention.

METHODS

Cross-sectional computer-assisted telephone interviews of persons aged 18-90 years were conducted by beyondblue in Australia in 2002 and 2004/05. Items assessed consideration of depression as a major general health or mental health problem, knowledge about prevalence of depression, usual age of onset for depression or anxiety and treatment preferences.

RESULTS

The surveys included 2003 and 3200 persons, respectively, with 285 and 400 aged between 18 and 25 years. Depression was not recognized by young persons as a major general health problem (1-2% of responses), but was the most frequently named mental health problem (37-42%). Younger persons were more likely than older persons to see depression as the major mental health problem, placing less emphasis on alcohol and other drug problems. They preferred first to seek help from family or friends (61-65%) and try non-pharmacological treatments. Although understanding of the helpfulness of several evidence-based treatments was good, many younger respondents still considered non-evidence-based treatments to be helpful. A quarter of subjects believed antidepressant medications were harmful and that alcohol use may be helpful.

CONCLUSIONS

Although knowledge about depression was good, young people do not recognize depression as a major general health problem and remain reluctant to use professional services. These attitudes represent significant barriers to seeking treatment early in the course of common mental health problems.

Peripheral insulin and brain structure in early Alzheimer disease

OBJECTIVE

Accumulating evidence suggests insulin and insulin signaling may be involved in the pathophysiology of Alzheimer disease (AD). The relationship between insulin-mediated glucoregulation and brain structure has not been assessed in individuals with AD.

METHODS

Nondemented (Clinical Dementia Rating [CDR] 0, n = 31) and early stage AD (CDR 0.5 and 1, n = 31) participants aged 65 years and older had brain MRI to determine whole brain and hippocampal volume and 3-hour IV glucose tolerance tests to determine glucose and insulin area under the curve (AUC). Linear regression models were used to assess the relationship of insulin and glucose with brain volume, cognition, and dementia severity.

RESULTS

In early AD, insulin and glucose AUCs were related to whole brain (insulin beta = 0.66, p < 0.001; glucose beta = 0.45, p < 0.01) and hippocampal volume (insulin beta = 0.42, p < 0.05; glucose beta = 0.46, p < 0.05). These relationships were independent of age, sex, body mass index, body fat, cardiorespiratory fitness, physical activity, cholesterol, and triglycerides. Insulin AUC, but not glucose, was associated with cognitive performance in early AD (beta = 0.40, p = 0.04). Insulin AUC was associated with dementia severity (Pearson r = -0.40, p = 0.03). Glucose and insulin were not related to brain volume or cognitive performance in nondemented individuals.

CONCLUSIONS

Increased peripheral insulin is associated with reduced Alzheimer disease (AD)-related brain atrophy, cognitive dysfunction, and dementia severity, suggesting that insulin signaling may play a role in the pathophysiology of AD.

Size and distribution of oxygen stores in harp and hooded seals from birth to maturity

Pinnipeds rely primarily on oxygen stores in blood and muscles to support aerobic diving; therefore rapid development of body oxygen stores (TBO(2)) is crucial for pups to transition from nursing to independent foraging. Here, we investigate TBO(2) development in 45 harp (Pagophilus groenlandicus) and 46 hooded (Cystophora cristata) seals ranging in age from neonates to adult females. We found that hooded seal adults have the largest TBO(2) stores yet reported (89.5 ml kg(-1)), while harp seal adults have values more similar to other phocids (71.6 ml kg(-1)). In adults, large TBO(2) stores resulted from large blood volume (harp169, hood 194 ml kg(-1)) and high muscle Mb content (harp 86.0, hood 94.8 mg g(-1)). In contrast, pups of both species had significantly lower mass-specific TBO(2 )stores than adults, and stores declined rather than increased during the nursing period. This decline was due to a reduction in mass-specific blood volume and the absence of an increase in the low Mb levels (harp 21.0, hood 31.5 mg g(-1)). Comparisons with other phocid species suggests that the pattern of blood and muscle development in the pre- and post-natal periods varies with terrestrial period, and that muscle maturation rates may influence the length of the postweaning fast. However, final maturation of TBO(2) stores does not take place until after foraging begins.

Laparoscopic ventral hernia repair: a single center experience

A retrospective chart review at the Carolinas Medical Center was performed on all patients who underwent laparoscopic ventral hernia repair (LVHR) from July 1998 through December 2003. LVHR was successfully completed in 270 of the 277 patients, or 98%, in whom it was attempted. Half of the patients (138/277) had at least one previous failed repair. The average defect measured 143.3 cm(2), and mesh was used in all repairs. The mean operating time was 168.3 min, mean blood loss was 50 cc, and average length of hospitalization was 3.0 days. Thirty-four complications occurred in 31 patients (11%). Only two mesh infections occurred (0.7%). At a mean follow-up period of 21 months, the rate of hernia recurrence was 4.7%. As experience grows and length of follow-up expands, LVHR may become the preferred approach for ventral hernia in difficult patients, especially obese patients and patients who have failed prior open repairs.

In vitro infectability of prosthetic mesh by methicillin-resistant Staphylococcus aureus

Although mesh use is important for effective herniorrhaphy in adults, prosthetic infections can cause serious morbidity. Bacterial adherence to the mesh is a known precursor to prosthetic infection. We compared the ability of common mesh prosthetics to resist bacterial adherence. The meshes studied included polypropylene (Marlex, expanded polytetrafluoroethylene (PTFE) with and without silver chlorhexidine coating (DualMesh Plus and Dualmesh) composite meshes (Composix E/X, Proceed, and Parietex Composite) and lightweight polypropylene meshes (TiMesh, Ultrapro, and Vypro). Fifteen samples of each mesh type were individually inoculated with a suspension of 10(8 )methicillin-resistant Staphylococcus aureus (MRSA) in tryptic soy broth. After incubation at 37 degrees C for 1 h, the mesh pieces were then removed and serially washed. The colony-forming units (CFU) of MRSA present in the initial inoculum, at the end of the 1-h warm-water bath (broth count), and the pooled washes (wash count), were determined using serial dilutions and spot plating. The bacteria not accounted for in the broth or wash counts were considered adhered to the mesh. Samples of each mesh type were also analyzed using scanning electron microscopy (SEM). Data are presented as the mean percentage adherence with ANOVA and Tukey's test used to determine significance (P<0.05). The DualMesh Plus mesh had no detectable MRSA in the broth or the pooled wash samples. Dualmesh had less adherence compared with Marlex, Proceed, and Vypro (P<0.05). Conversely, Vypro had a statistically higher adherence (96%, P<0.05) as compared to TiMesh, Ultrapro, Composix E/X, and Parietex Composite. SEM confirmed bacterial adherence to all the mesh types except DualMesh Plus. The ability of a biomaterial to resist infection has an important clinical significance. DualMesh Plus, due to its antimicrobial coating, is the only mesh type of the nine tested that demonstrated a bactericidal property. Standard PTFE (Dualmesh) also had less bacterial adherence. Vypro demonstrated an increase in bacterial adherence; this was possibly due to the multifilament polyglactin 910 weaved within the prolene component of the mesh.

The pathology of the substantia nigra in Alzheimer disease with extrapyramidal signs

BACKGROUND

Extrapyramidal signs (EPS) are common in Alzheimer disease (AD) and increase in prevalence as AD advances. The neuropathologic substrate responsible for EPS in AD remains to be fully characterized.

METHODS

Subjects had a clinical diagnosis of AD confirmed by neuropathologic examination. EPS during life were documented by clinical methods assessing bradykinesia, cogwheel rigidity, rest tremor, and parkinsonian gait. Subjects with EPS and previous neuroleptic exposure were excluded. Twenty-eight subjects were in the EPS group and 104 subjects were without EPS. Neuron loss, alpha-synuclein (ASYN)-labeled pathology, and tau-labeled pathology in the substantia nigra were measured using semiquantitative techniques such that higher scores represented increased pathologic burden.

RESULTS

Presence of nigral ASYN-labeled pathology was more common (50 vs 28.9%; p < 0.05) in the EPS group than in those without EPS. There was more nigral neuron loss in the EPS group (1.50 vs 1.11 in no-EPS group; p < 0.05). Tau-labeled burden was not different by group comparisons; however, EPS onset at later stages of dementia severity was associated with increased tau-labeled pathology (Kendall tau-B = 0.48, p < 0.01) and this association remained after controlling for dementia severity at death. Additionally, moderate to severe tau burden was more common in the subgroup with "pure AD" (definite AD without other neuropathology) with EPS (81.8%) than cases without EPS (49.0%; p < 0.05). Four subjects with EPS (14.3%) had little to no significant nigral pathologic changes.

CONCLUSIONS

Clinically detected extrapyramidal signs (EPS) in Alzheimer disease (AD) are associated with substantia nigra pathology including alpha-synuclein aggregation, hyperphosphorylated tau accumulation, and neuron loss that may account for the increasing prevalence of EPS as AD progresses. In some cases, limited nigral pathology suggests extranigral factors in the clinical symptoms of EPS.

Positive relationships between public awareness activity and recognition of the impacts of depression in Australia

OBJECTIVE

This report records the level of exposure to depression-related information across the Australian community and explores associations with recognition of depression and relevant sociodemographic factors.

METHOD

A cross-sectional telephone survey was conducted with a representative community sample. Participants consisted of 3200 respondents (400 respondents across each Australian State/Territory).

RESULTS

Sixty-five point four per cent (n=2089/3193) of respondents indicated that they or someone close to them had experienced depression, of whom 18.7% (n=391/2089) reported a personal experience of this illness. Various measures of recent exposure to depression-related information were high with 69.0% (n=2207/3200) reporting that they had seen, read or heard something in the media in the last 12 months. Recognition of beyondblue: the national depression initiative was also surprisingly high (61.9%, 1982/3200). Those with greater understanding that depression is common and debilitating were more likely to recall recent media stories, spontaneously recall relevant organizations such as beyondblue, to have had direct or family experiences, to be younger and to have achieved higher levels of education. Depression, however, is rarely mentioned (1.3%, 47/3720) as a major general health as distinct from a mental health problem.

CONCLUSION

The active promotion of depression-related material to the community appears to have contributed to recognition of the commonality and impacts of this illness. Although depression is commonly recognized as a mental health problem, it is not yet considered a major general health problem. Further, like many public health campaigns, those initially reached appear more likely to be female, younger, better educated and residing in metropolitan areas.

Development of body oxygen stores in harbor seals: effects of age, mass, and body composition

Harbor seal pups are highly precocial and can swim and dive at birth. Such behavioral maturity suggests that they may be born with mature body oxygen stores or that stores develop quickly during the nursing period. To test this hypothesis, we compared the blood and muscle oxygen stores of harbor seal pups, yearlings, and adults. We found that pups had smaller oxygen stores than adults (neonates 57%, weaned pups 75%, and yearlings 90% those of adults), largely because neonatal myoglobin concentrations were low (1.6+/-0.2 g% vs. 3.8+/-0.3 g% for adults) and changed little during the nursing period. In contrast, blood oxygen stores were relatively mature, with nursing pups having hematocrit (55%+/-0.2%), hemoglobin (21.7+/-0.4 g%), and blood volume (12.3+/-0.5 mL/kg) only slightly lower than the corresponding values for adults (57%+/-0.2%, 23.8+/-0.3 g %, and 15.0+/-0.5 mL/kg). Because neonatal pups had relatively high metabolic rates (11.0 mL O2/kg min), their calculated aerobic dive limit was less than 50% that of adults. These results suggest that harbor seals' early aquatic activity is primarily supported by rapid development of blood, with immature muscle oxygen stores and elevated use rates limiting aerobic diving ability.

Progressive posterior cortical dysfunction: a clinicopathologic series

BACKGROUND

Atypical presentations of neurodegenerative dementing disorders include the syndrome of progressive posterior cortical dysfunction (PPCD) involving selective higher order visuospatial deficits. The neuropathologic correlates of PPCD remain poorly defined.

METHODS

This is a retrospective case series of 27 individuals (14 men, 13 women) diagnosed clinically with PPCD. Participants were either enrolled in the Alzheimer's Disease Research Center (ADRC) or referred to the memory diagnostic center of an urban academic medical center. Clinical evaluations included physical and neurologic examinations, the Clinical Dementia Rating (CDR), and psychometric measures. Neuropathologic examinations were completed in 21 individuals with PPCD. Psychometric measures from 65 individuals with mild dementia of the Alzheimer type (DAT) enrolled in the ADRC were used for comparison.

RESULTS

Neuropathologic etiologies of PPCD were Alzheimer disease (AD) (n = 13), AD plus Parkinson disease (n = 1), AD-Lewy body variant (n = 2), dementia with Lewy bodies plus progressive subcortical gliosis of Neumann (n = 1), corticobasal degeneration (n = 2), and prion-associated diseases: Creutzfeldt-Jakob disease (n = 1) and fatal familial insomnia (n = 1). Confirming the clinical impression, psychometric profiles for individuals with PPCD differed from those of people with DAT alone and revealed disproportionate deficits on measures of visuospatial ability.

CONCLUSIONS

AD was the most frequent cause of PPCD in this series, although non-Alzheimer's dementing disorders also should be considered.

Effect of carbon dioxide pneumoperitoneum and wound closure technique on port site tumor implantation in a rat model

BACKGROUND

The purpose of this study was to evaluate the effects of carbon dioxide (CO2) pneumoperitoneum and wound closure technique on port site tumor implantation.

METHODS

A standard quantity of rat mammary adenocarcinoma (SMT2A)was allowed to grow in a flank incision in Wistar-Furth rats (n = 90) for 14 days. Thereafter, 1-cm incisions were made in each animal in three quadrants. There were six control animals. The experimental animals were divided into a 60-min CO2 pneumoperitoneum group (n = 42) and a no pneumoperitoneum (n = 42) group. The flank tumor was lacerated transabdominally in the experimental groups. The three wound sites were randomized to closure of (a) skin; (b) skin and fascia; and (c) skin, fascia, and peritoneum. The abdominal wounds were harvested en bloc on postoperative day 7.

RESULTS

Histologic comparison of the port sites in the pneumoperitoneum and no-pneumoperitoneum groups did not demonstrate a statistically significant difference in tumor implantation for any of the closure methods. Evaluation of the closure techniques showed no statistical difference between the pneumoperitoneum group and the no-pneumoperitoneum group in the incidence of port site tumor implantation. Within the no-pneumoperitoneum group, there was a significant increase (p = 0.03) in tumor implantation with skin closure alone vs all three layers. Additionally, when we compared all groups by closure technique, the rate of tumor implantation was found to be significantly higher (p = 0.01) for skin closure alone vs closure of all three layers.

CONCLUSIONS

This study suggests that closure technique may influence the rate of port site tumor implantation. The use of a CO2 pneumoperitoneum did not alter the incidence of port site tumor implantation at 7 days postoperatively.

Cirrhosis is not a contraindication to laparoscopic surgery

BACKGROUND

Cirrhosis of the liver contributes significantly to morbidity and mortality in abdominal surgery. The proven benefits of laparoscopy seem especially applicable to patients with this complex disease. This study evaluates the safety and efficacy of laparoscopic procedures in a series of consecutively treated patients with biopsy-proven cirrhosis.

METHODS

The medical records of all patients with biopsy-proven cirrhosis undergoing laparoscopic surgery at the authors' medical center between January 2000 and December 2003 were retrospectively reviewed.

RESULTS

A total of 50 patients (27 men and 23 women) underwent 52 laparoscopic procedures. Among these 50 patients were 39 patients with Child-Pugh classification A cirrhosis, 10 with classification B, and 1 with classification C, who underwent a variety of laparoscopic procedures including cholecystectomy (n = 22), splenectomy (n = 18), colectomy (n = 4), diagnostic laparoscopy (n = 3), ventral hernia repair (n = 1), Nissen fundoplication (n = 1), Heller myotomy (n = 1), Roux-en-Y gastric bypass (n = 1), and radical nephrectomy (n = 1). There were two conversions (4%) to an open procedure. The mean operative time was 155 min. Estimated blood loss averaged 124 ml for all procedures, and 20 patients (40%) required perioperative transfusion of blood products. One patient required a single blood transfusion postoperatively because of anemia. No one experienced hepatic decompensation. Overall morbidity was 16%. There were no deaths. The mean length of hospitalization was 3 days.

CONCLUSIONS

Although technically challenging because portal hypertension, varices, and thrombocytopenia frequently coexist, basic and advanced laparoscopic procedures are safe for patients with mild to moderate cirrhosis of the liver.

Overdose in young people using heroin: associations with mental health, prescription drug use and personal circumstances

OBJECTIVE

To identify patterns of mental health, prescription drug use and personal circumstances associated with heroin overdose in young people.

DESIGN

Linkage of data on use of Pharmaceutical Benefits Scheme (PBS) prescription drugs with data from a self-report questionnaire.

SETTING

Inner metropolitan Melbourne, Australia.

SUBJECTS

163 young people, 15-30 years, using heroin.

MAIN OUTCOME MEASURES

Personal circumstances, mental health (as measured by various scales), and PBS-listed prescription drug use.

RESULTS

Young people using heroin reported high rates of feelings of hopelessness, depression, antisocial behaviour, self-harm and diagnosed mental illness. A prior history of overdose was associated with previous mental illness, which in turn was associated with being female, having poor social support, being dissatisfied with relationships, and living alone or in temporary accommodation. While feelings of hopelessness and antisocial behaviour were strongly associated with overdose history, the number of PBS prescription drugs used had a very strong relationship with overdose, particularly benzodiazepines, other opioids, tricyclic antidepressants and tranquillisers.

CONCLUSIONS

Further research to explore causal relationships between prescription drugs and heroin overdose is warranted. Improved data linkage to PBS records for general practitioners may facilitate safer prescribing practices.

Seeking drugs or seeking help? Escalating "doctor shopping" by young heroin users before fatal overdose

OBJECTIVE

To identify prescription drug-seeking behaviour patterns among young people who subsequently died of heroin-related overdose.

DESIGN

Linkage of Medicare and Pharmaceutical Benefits Scheme and Coroner's Court records from Victoria.

SUBJECTS

Two hundred and two 15-24-year-olds who died of heroin-related overdose between 6 January 1994 and 6 October 1999.

MAIN OUTCOME MEASURES

Patterns of use of medical services and prescription drugs listed on the Pharmaceutical Benefits Scheme in the years before death, and use of all drugs just before death.

RESULTS

Polydrug use was reported in 90% of toxicology reports, and prescription drugs were present in 80% of subjects. Subjects accessed medical services six times more frequently than the general population aged 14-24 years, and more than half of all prescribed drugs were those prone to misuse, such as benzodiazepines and opioid analgesics. A pattern of increasing drug-seeking behaviour in the years before death was identified, with doctor-visitation rates, number of different doctors seen and rates of prescriptions peaking in the year before death.

CONCLUSIONS

An apparent increase in "doctor shopping" in the years before heroin-related death may reflect the increasing misuse of prescription drugs, but also an increasing need for help. Identification of a pattern of escalating doctor shopping could be an opportunity for intervention, and potentially, reduction in mortality.

Adolescent resilience: a concept analysis

There is need for greater clarity around the concept of resilience as it relates to the period of adolescence. Literature on resilience published between 1990 and 2000 and relevant to adolescents aged between 12- and 18-years of age was reviewed with the aim of examining the various uses of the term, and commenting on how specific ways of conceptualizing of resilience may help develop new research agendas in the field. By bringing together ideas on resilience from a variety of research and clinical perspectives, the purpose of the review is to explicate core elements of resilience in more precise ways, in the hope that greater conceptual clarity will lead to a range of tailored interventions that benefit young people.

The effect of long-term atmospheric CO2 enrichment on the intrinsic water-use efficiency of sour orange trees

Every two months of 1992, as well as on three occasions in 1994-1995, we obtained leaf samples together with samples of surrounding air from eight well-watered and fertilized sour orange (Citrus aurantium L.) trees that were growing out-of-doors at Phoenix, Arizona, USA. These trees had been planted in the ground as small seedlings in July of 1987 and enclosed in pairs by four clear-plastic-wall open-top chambers of which two have been continuously maintained since November of that year at a CO2 concentration of 400 micromol mol(-1) and two have been maintained at 700 micromol mol(-1). In September 2000, we also extracted north-south and east-west oriented wood cores that passed through the center of each tree's trunk at a height of 45 cm above the ground. Stable-carbon isotope ratios (13C/12C) derived from these leaf, wood and air samples were used to evaluate each tree's intrinsic water-use efficiency (iWUE). The grand-average result was an 80% increase in this important plant parameter in response to the 300 micromol mol(-1) increase in atmospheric CO2 concentration employed in the study. This increase in sour orange tree iWUE is identical to the long-term CO2-induced increase in the trees' production of wood and fruit biomass, which suggests there could be little to no change in total water-use per unit land area for this species as the air's CO2 content continues to rise. It is also identical to the increase in the mean iWUE reported for 23 groups of naturally occurring trees scattered across western North America that was caused by the historical rise in the air's CO2 content that occurred between 1800 and 1985.

Depression in young people: what causes it and can we prevent it?

Cumulative adverse experiences, including negative life events and early childhood adversity, together with parental depression and/or non-supportive school or familial environments, place young people at risk for developing depression. Enhanced life skills and supportive school and family environments can mediate the effect of stressful life events. Programs that enhance the school environment are associated with improved behaviour and wellbeing. Interventions that teach cognitive skills are associated with a short-term reduction in depressive symptoms. Current evidence suggests that for an intervention to be sustainable it must encompass multiple components across several levels: classroom, curriculum, whole school, and the school-community interface. Teaching interpersonal skills, including cognitive and problem-solving skills, should be coupled with the promotion of positive school and family environments to prevent depression in young people.

A protective glycosylphosphatidylinositol-anchored membrane protein of Plasmodium yoelii trophozoites and merozoites contains two epidermal growth factor-like domains

Using sera from mice immunized and protected against Plasmodium yoelii malaria, we identified a novel blood-stage antigen gene, pypag-2. The 2.1-kb pypag-2 cDNA contains a single open reading frame that encodes a 409-amino-acid protein with a predicted molecular mass of 46.8 kDa. Unlike many characterized plasmodial antigens, blocks of tandemly repeated amino acids are lacking in the pypAg-2 protein sequence. Recombinant pypAg-2, comprising the full-length protein minus the predicted N-terminal signal and C-terminal anchor sequences, was produced and used to raise a high-titer polyclonal rabbit antiserum. This antiserum was used to identify and characterize the native protein through immunoblotting, immunoprecipitation and immunofluorescence assays. Consistent with the presence of a glycosylphosphatidylinositol anchor, pypAg-2 fractionated with the detergent phase of Triton X-114-solubilized proteins and could be metabolically labeled with [(3)H]palmitic acid. By immunofluorescence, pypAg-2 expression was localized to both the trophozoite and merozoite membranes. Similar to Plasmodium falciparum merozoite surface protein 1, pypAg-2 contains two C-terminal epidermal growth factor (EGF)-like domains. Most importantly, immunization with recombinant pypAg-2 protected mice against lethal P. yoelii malaria. Thus, pypAg-2 is a target of protective immune responses and represents a novel addition to the family of merozoite surface proteins that contain one or more EGF-like domains.

An unusual tryptophan-rich domain characterizes two secreted antigens of Plasmodium yoelii-infected erythrocytes

Previously, we reported the characterization of pypAg-1, a novel protective membrane protein of Plasmodium yoelii-infected erythrocytes. Immunization studies indicated that pypAg-1 contained at least two protective epitopes. One of these determinants was associated with the N-terminal portion of pypAg-1, that also included a 220 amino acid domain unusually rich in tryptophan residues. Using sera from mice immunized against P. yoelii, we have identified a second related antigen, pypAg-3. The pypag-3 cDNA encodes a 43 kDa blood-stage protein that is also characterized by the presence of a 220 residue tryptophan-rich domain. Of particular interest, sequence comparisons revealed that 24 tryptophan residues are positionally conserved between pypAg-1 and pypAg-3. Otherwise, the two antigens share limited sequence similarity. Full-length recombinant pypAg-3 was expressed, purified and used to produce a high titer polyclonal rabbit antiserum. As with pypAg-1, immunofluorescence studies showed that pypAg-3 is expressed in the cytoplasm and associated with the membrane of P. yoelii infected erythrocytes. In addition, pypAg-1 and pypAg-3 appear to be secreted proteins, as both were detected in culture supernatants of P. yoelii-infected erythrocytes. Finally, metabolically labeled pypAg-1 and pypAg-3 secreted from parasitized cells bind to the surface of uninfected, normal mouse erythrocytes. As such, the conservation of the unusual tryptophan-rich domain between two blood-stage malarial proteins with similar biological properties suggests that it may be important for protein export and/or function.