Early prediction of mental health problems following military deployment: Integrating pre- and post-deployment factors in neural network models

Military personnel deployed to war zones are at increased risk of mental health problems such as posttraumatic stress disorder (PTSD) or depression. Early pre- or post-deployment identification of those at highest risk of such problems is crucial to target intervention to those in need. However, sufficiently accurate models predicting objectively assessed mental health outcomes have not been put forward. In a sample consisting of all Danish military personnel who deployed to war zones for the first (N = 27,594), second (N = 11,083) and third (N = 5,161) time between 1992 and 2013, we apply neural networks to predict psychiatric diagnoses or use of psychotropic medicine in the years following deployment. Models are based on pre-deployment registry data alone or on pre-deployment registry data in combination with post-deployment questionnaire data on deployment experiences or early post-deployment reactions. Further, we identified the most central predictors of importance for the first, second, and third deployment. Models based on pre-deployment registry data alone had lower accuracy (AUCs ranging from 0.61 (third deployment) to 0.67 (first deployment)) than models including pre- and post-deployment data (AUCs ranging from 0.70 (third deployment) to 0.74 (first deployment)). Age at deployment, deployment year and previous physical trauma were important across deployments. Post-deployment predictors varied across deployments but included deployment exposures as well as early post-deployment symptoms. The results suggest that neural network models combining pre- and early post-deployment data can be utilized for screening tools that identify individuals at risk of severe mental health problems in the years following military deployment.

Feasibility of Virtual Reality Exposure Therapy in the Treatment of Danish Veterans with Post-Traumatic Stress Disorder: A Mixed Method Pilot Study

The BraveMind virtual reality exposure therapy (VRET) has been developed and has shown efficacy for U.S. service members and veterans. As the first study to date, the present study examined the feasibility of BraveMind VRET for non-U.S. military veterans. Moreover, the study sought to explore in-depth the participants' experiences with BraveMind VRET. Nine Danish veterans with post-traumatic stress disorder (PTSD) after deployment to Afghanistan participated in the study. PTSD, depression, and quality of life were assessed at pretreatment, post-treatment, and 3-month followup. The treatment consisted of 10 BraveMind VRET sessions. Semistructured interviews with treatment completers were conducted post-treatment to ascertain views about the treatment, in general, and the BraveMind VR system in particular. Thematic qualitative analysis was conducted at the semantic level using an inductive approach. There were significant reductions in pre- to post-treatment self-reported PTSD and significant improvements in quality of life. Treatment gains were maintained at 3-month followup. Pre- to post-treatment Cohen's d effect sizes were large for self-reported PTSD (PTSD Checklist-Civilian Version [PCL-C]: d = 1.55). Qualitative results indicated that the virtual environment of the BraveMind VR system does not entirely map the reality of Danish soldiers in Afghanistan. However, this was not experienced as a hindering factor in therapy. Findings indicate that BraveMind VRET is an acceptable, safe, and effective treatment for Danish veterans with PTSD. The qualitative results emphasize the importance of a strong therapeutic alliance, as VRET is experienced as more emotional straining than regular trauma-focused therapy.

Forecasting military mental health in a complete sample of Danish military personnel deployed between 1992-2013

OBJECTIVE

Mental health problems (MHP) are a relatively common consequence of deployment to war zones. Early identification of those at risk of post-deployment MHP would improve prevention efforts. However, screening instruments based on linear models have not been successful. Machine learning (ML) has shown promise for providing the methodological frame for better prognostic models.

METHODS

The study population was all Danish military personnel deployed for the first time between January 1, 1992 and December 31, 2013. From extensive registry data, 21 pre- or at-deployment predictors comprising early adversity, social, clinical and demographic variables were used to predict psychiatric contacts (psychiatric diagnosis and/or use of psychotropic medicine) occurring within 6.5 years after homecoming. Four supervised ML methods (penalized logistic regression, random forests, support vector machines and gradient boosting machines) were compared in ability to classify those with high risk of post-deployment MHP and those without.

RESULTS

Of 27594 subjects, 2175 (8%) had a psychiatric contact. All four ML methods applied had performances well above chance (Area under the Receiver-operating Curve 0.62-0.68). Positive predictive value for the best model was 0.16. A range of pre-deployment factors were found to be predictive of post-deployment psychiatric contacts.

CONCLUSIONS

ML methods can be useful in early identification of soldiers with high risk of MPH in the years following their first deployment. However, performances were modest and positive predictive values were low, limiting the applicability of the models for pre-deployment screening. Future studies should include neurobiological data and deployment experiences to increase accuracy of the models.

International meta-analysis of PTSD genome-wide association studies identifies sex- and ancestry-specific genetic risk loci

The risk of posttraumatic stress disorder (PTSD) following trauma is heritable, but robust common variants have yet to be identified. In a multi-ethnic cohort including over 30,000 PTSD cases and 170,000 controls we conduct a genome-wide association study of PTSD. We demonstrate SNP-based heritability estimates of 5-20%, varying by sex. Three genome-wide significant loci are identified, 2 in European and 1 in African-ancestry analyses. Analyses stratified by sex implicate 3 additional loci in men. Along with other novel genes and non-coding RNAs, a Parkinson's disease gene involved in dopamine regulation, PARK2, is associated with PTSD. Finally, we demonstrate that polygenic risk for PTSD is significantly predictive of re-experiencing symptoms in the Million Veteran Program dataset, although specific loci did not replicate. These results demonstrate the role of genetic variation in the biology of risk for PTSD and highlight the necessity of conducting sex-stratified analyses and expanding GWAS beyond European ancestry populations.

Itch relief in patients with psoriasis: effectiveness of calcipotriol plus betamethasone dipropionate foam

BACKGROUND

Itch is common in psoriasis, adversely affecting health-related quality of life (HRQoL) and sleep.

OBJECTIVE

We evaluated the efficacy of topical fixed-dose combination calcipotriol 50 μg/g plus betamethasone dipropionate 0.5 mg/g cutaneous foam (Cal/BD foam) on itch, itch-related sleep loss and HRQoL vs. foam vehicle.

METHODS

We pooled data from three Phase II/III trials (NCT01536886/NCT01866163/NCT02132936) of Cal/BD foam vs. foam vehicle in adults with mild-severe psoriasis. For itch-related analyses, patients with baseline itch visual analogue scale (VAS) >40 (range 0-100) were analysed. Outcomes included the following: itch VAS reduction >40, ≥70% improvement in itch (Itch70) or itch-related sleep loss, 75% improvement in modified Psoriasis Area and Severity Index (excluding head; mPASI75) and Dermatology Life Quality Index (DLQI) scores 0/1 through 4 weeks.

RESULTS

Of 837 patients, 800 had baseline itch VAS >0 (Cal/BD foam, n = 610; foam vehicle, n = 190); 484 had baseline itch VAS >40. There was no correlation between itch VAS score and mPASI at baseline (R²  = 0.021). In patients with baseline itch VAS >40, more patients achieved itch VAS reduction >40 in the active vs. vehicle group from Day 5 onwards (Day 5: 57.5% vs. 40.2% [P < 0.05]; Week 4: 83.0% vs. 45.8% [P < 0.001]). More Cal/BD-foam-treated patients achieved Itch70 at Day 3 (34.2% vs. 22.5%; P < 0.05) through to Week 4 (79.3% vs. 38.1%; P < 0.001). In patients with baseline itch VAS >40 and sleep loss >20, improvements in itch-related sleep loss occurred at Week 1 and continued through 4 weeks. Itch-related improvements occurred before improvements in mPASI75. There were significant differences in the proportion of Cal/BD-foam- vs. foam-vehicle-treated patients with baseline DLQI >10 (n = 172 vs. n = 50) achieving DLQI ≤1 (25.0% vs. 4.0%; P = 0.001) and DLQI 0 (17.4% vs. 2.0%; P = 0.006) at Week 4.

CONCLUSION

Compared with foam vehicle, Cal/BD foam offers more rapid and effective itch relief, with associated significant improvements in sleep and DLQI.

Post-traumatic stress following military deployment: Genetic associations and cross-disorder genetic correlations

BACKGROUND

Post-traumatic stress disorder (PTSD) is a complex psychiatric disorder that occurs with relatively high frequency after deployment to warzones (∼10%). While twin studies have estimated the heritability to be up to 40%, thus indicating a considerable genetic component in the etiology, the biological mechanisms underlying risk and development of PTSD remain unknown.

METHODS

Here, we conduct a genome-wide association study (GWAS; N = 2,481) to identify genome regions that associate with PTSD in a highly homogenous, trauma-exposed sample of Danish soldiers deployed to war and conflict zones. We perform integrated analyses of our results with gene-expression and chromatin-contact datasets to prioritized genes. We also leverage on other large GWAS (N>300,000) to investigate genetic correlations between PTSD and other psychiatric disorders and traits.

RESULTS

We discover, but do not replicate, one region, 4q31, close to the IL15 gene, which is genome-wide significantly associated with PTSD. We demonstrate that gene-set enrichment, polygenic risk score and genetic correlation analyses show consistent and significant genetic correlations between PTSD and depression, insomnia and schizophrenia.

LIMITATIONS

The limited sample size, the lack of replication, and the PTSD case definition by questionnaire are limitations to the study.

CONCLUSIONS

Our results suggest that genetic perturbations of inflammatory response may contribute to the risk of PTSD. In addition, shared genetic components contribute to observed correlations between PTSD and depression, insomnia and schizophrenia.

Mental Health Care for Service Members and Their Families Across the Globe

The U.S. Defense Department partnered with the International Initiative for Mental Health Leadership on effective leadership and operational practices for delivery of mental health (MH) as well as addiction services throughout the world for Service Members (SM) and beneficiaries. A Military Issues Work Group (MIWG) was established in 2011 to focus on challenges experienced by military SM and beneficiaries among countries. The MIWG found common concerns related to MH care delivery to rural and remote beneficiaries. Gaps in access to care were identified and prioritized to explore. This led to better collaboration and understanding of telemental health (TMH) practices and technology applications (apps) which increase access to care for rural and remote SMs and beneficiaries. An assessment of the number of SMs and dependents distant from MH care services in the USA was conducted, as well as an environmental scan for psychological health-focused mobile apps and TMH services geared toward SM, veterans, and beneficiaries. The MIWG is developing a compendium of existing military TMH programs and apps that address MH concerns and extant literature on use of technology to extend global access to care for military members and their families across the world.

Leadership and post-traumatic stress disorder: are soldiers' perceptions of organizational justice during deployment protective?

Background: Soldiers' perception of leadership during military deployment has gained research attention as a potentially modifiable factor to buffer against the development of postdeployment post-traumatic stress disorder (PTSD). Within nonmilitary research, the organizational justice (OJ) framework, i.e. distributive justice, procedural justice (PJ) and interactional justice (IJ), has been found to relate to mental health outcomes. Aspects of OJ may, therefore, be protective against PTSD. Objectives: We examined the prospective relationship between aspects of OJ, namely the perceptions of PJ and IJ by subordinate soldiers without leadership obligations in relationship to immediate superiors and PTSD. Method: Participants were soldiers (n = 245) deployed to Helmand Province in Afghanistan in 2009. Logistic regression procedures were used. The primary analysis measured PTSD cases using the Structured Clinical Interview for DSM-IV-TR Axis-I Disorder (SCID) 2½ years after homecoming. PJ/IJ was measured during deployment with a 6-item composite measure ranging from 0 to 12. Supplementary primary analyses were performed with PJ/IJ measured before and immediately after deployment. A secondary PJ/IJ analysis also tested against four postdeployment measures with the Post-Traumatic Stress Disorder Checklist Civilian (PCL-C) dichotomized at screening symptom levels. Results: Higher levels of perceived PJ/IJ for soldiers without leadership obligations during deployment had a prospective relation (OR = 0.86, 95% CI = 0.75-0.98) with PTSD on the SCID 2½ years after homecoming after adjustment for factors including predeployment PTSD symptoms, trauma and combat exposure, and state affectivity. Similar results were found by measuring PJ/IJ before (OR = 0.83, 95% CI = 0.71-0.95) but not immediately after homecoming (OR = 0.97, 95% CI = 0.85-1.11). A relationship with PTSD symptoms at the screening level at the four measurements of PCL-C was found, but only when predeployment PTSD symptoms were not controlled for. Conclusions: These results suggest that PJ/IJ exercised by superiors in relation to military deployments may protect subordinate soldiers against the development of postdeployment PTSD.

Does size really matter? A multisite study assessing the latent structure of the proposed ICD-11 and DSM-5 diagnostic criteria for PTSD

Background: Researchers and clinicians within the field of trauma have to choose between different diagnostic descriptions of posttraumatic stress disorder (PTSD) in the DSM-5 and the proposed ICD-11. Several studies support different competing models of the PTSD structure according to both diagnostic systems; however, findings show that the choice of diagnostic systems can affect the estimated prevalence rates. Objectives: The present study aimed to investigate the potential impact of using a large (i.e. the DSM-5) compared to a small (i.e. the ICD-11) diagnostic description of PTSD. In other words, does the size of PTSD really matter? Methods: The aim was investigated by examining differences in diagnostic rates between the two diagnostic systems and independently examining the model fit of the competing DSM-5 and ICD-11 models of PTSD across three trauma samples: university students (N = 4213), chronic pain patients (N = 573), and military personnel (N = 118). Results: Diagnostic rates of PTSD were significantly lower according to the proposed ICD-11 criteria in the university sample, but no significant differences were found for chronic pain patients and military personnel. The proposed ICD-11 three-factor model provided the best fit of the tested ICD-11 models across all samples, whereas the DSM-5 seven-factor Hybrid model provided the best fit in the university and pain samples, and the DSM-5 six-factor Anhedonia model provided the best fit in the military sample of the tested DSM-5 models. Conclusions: The advantages and disadvantages of using a broad or narrow set of symptoms for PTSD can be debated, however, this study demonstrated that choice of diagnostic system may influence the estimated PTSD rates both qualitatively and quantitatively. In the current described diagnostic criteria only the ICD-11 model can reflect the configuration of symptoms satisfactorily. Thus, size does matter when assessing PTSD.

Cognitive ability and risk of post-traumatic stress disorder after military deployment: an observational cohort study

BACKGROUND

Studies of the association between pre-deployment cognitive ability and post-deployment post-traumatic stress disorder (PTSD) have shown mixed results.

AIMS

To study the influence of pre-deployment cognitive ability on PTSD symptoms 6-8 months post-deployment in a large population while controlling for pre-deployment education and deployment-related variables.

METHOD

Study linking prospective pre-deployment conscription board data with post-deployment self-reported data in 9695 Danish Army personnel deployed to different war zones in 1997-2013. The association between pre-deployment cognitive ability and post-deployment PTSD was investigated using repeated-measure logistic regression models. Two models with cognitive ability score as the main exposure variable were created (model 1 and model 2). Model 1 was only adjusted for pre-deployment variables, while model 2 was adjusted for both pre-deployment and deployment-related variables.

RESULTS

When including only variables recorded pre-deployment (cognitive ability score and educational level) and gender (model 1), all variables predicted post-deployment PTSD. When deployment-related variables were added (model 2), this was no longer the case for cognitive ability score. However, when educational level was removed from the model adjusted for deployment-related variables, the association between cognitive ability and post-deployment PTSD became significant.

CONCLUSIONS

Pre-deployment lower cognitive ability did not predict post-deployment PTSD independently of educational level after adjustment for deployment-related variables.

DECLARATION OF INTEREST

None.

COPYRIGHT AND USAGE

© The Royal College of Psychiatrists 2017. This is an open access article distributed under the terms of the Creative Commons Non-Commercial, No Derivatives (CC BY-NC-ND) license.

Assessing PTSD in the military: Validation of a scale distributed to Danish soldiers after deployment since 1998

Since 1998, soldiers deployed to war zones with the Danish Defense (≈31,000) have been invited to fill out a questionnaire on post-mission reactions. This provides a unique data source for studying the psychological toll of war. Here, we validate a measure of PTSD-symptoms from the questionnaire. Soldiers from two cohorts deployed to Afghanistan with the International Security Assistance Force (ISAF) in 2009 (ISAF7, N = 334) and 2013 (ISAF15, N = 278) filled out a standard questionnaire (Psychological Reactions following International Missions, PRIM) concerning a range of post-deployment reactions including symptoms of PTSD (PRIM-PTSD). They also filled out a validated measure of PTSD-symptoms in DSM-IV, the PTSD-checklist (PCL). We tested reliability of PRIM-PTSD by estimating Cronbach's alpha, and tested validity by correlating items, clusters, and overall scale with corresponding items in the PCL. Furthermore, we conducted two confirmatory factor analytic models to test the factor structure of PRIM-PTSD, and tested measurement invariance of the selected model. Finally, we established a screening and a clinical cutoff score by application of ROC analysis. We found high internal consistency of the PRIM-PTSD (Cronbach's alpha = 0.88; both cohorts), strong item-item (0.48-0.83), item-cluster (0.43-0.72), cluster-cluster (0.71-0.82) and full-scale (0.86-0.88) correlations between PRIM-PTSD and PCL. The factor analyses showed adequate fit of a one-factor model, which was also found to display strong measurement invariance across cohorts. ROC curve analysis established cutoff scores for screening (sensitivity = 1, specificity = 0.93) and clinical use (sensitivity = 0.71, specificity = 0.98). In conclusion, we find that PRIM-PTSD is a valid measure for assessing PTSD-symptoms in Danish soldiers following deployment.

The influence of pre-deployment cognitive ability on post-traumatic stress disorder symptoms and trajectories: The Danish USPER follow-up study of Afghanistan veterans

OBJECTIVE

New trajectories of PTSD symptoms have recently been identified in war exposed army veterans. The aim of this army veterans study was to examine whether pre-deployment cognitive ability is associated with the risk of developing PTSD symptoms or non-resilient PTSD trajectories.

METHOD

Follow up study in 428 Danish soldiers, deployed to Afghanistan in 2009, who were assessed at six occasions from pre-deployment to three years post-deployment. Pre-deployment vulnerabilities, deployment and homecoming stressors were measured. Pre-deployment cognitive test scores on Børge Priens Prøve (based on logical, verbal, numerical and spatial reasoning) were converted to a mean of 100 and with a standard deviation of 15.

RESULTS

Higher pre-deployment cognitive ability scores were associated with lower risk of PTSD symptoms as assessed by the Posttraumatic Stress Disorder Checklist-Civilian Version (PCL-C) 2.5 years post-deployment (OR=0.97; 95% CI 0.95-1.00) after adjustment for educational length, baseline PCL-C score and perceived war-zone stress. Compared to a resilient trajectory, a non-resilient relieved-worsening trajectory (high baseline mental symptoms, being symptom free during deployment and a drastic increase in PTSD symptoms at the final assessments of PTSD symptoms) had significantly lower cognitive scores by a mean difference of 14.5 (95% CI 4.7-24.3). This trajectory (n=9) comprised 26.5% of soldiers with moderate-severe PTSD symptoms 2.5 years post-deployment.

CONCLUSION

We confirmed an inverse association between pre-deployment cognitive ability and risk of PTSD symptoms, and observed significantly lower mean pre-deployment cognitive scores in one non-resilient PTSD trajectory. If replicated, this might inform relevant prevention efforts for soldiers at pre-deployment.

Abstract P2-04-03: Can the interval cancer ratio diminish the need for background incidence estimates as a mammography screening programme performance indicator?

Background:

Interval cancers (IC) are cancers that are discovered within the interval between two screening examinations, i.e. they present themselves clinically before the next scheduled screening examination.

A mammography screening programme that is run in a population with a high breast cancer incidence can have a high interval cancer rate, and still have as protective an effect as a screening programme with a low IC-rate run in a population with a low breast cancer incidence. The effectiveness of a mammography screening programme is therefore normally evaluated by comparing the IC-rate to the expected breast cancer incidence without screening, i.e. the proportional interval cancer rate. The expected breast cancer incidence in absence of screening, or background incidence is, however, difficult to approximate, as the introduction of a screening program makes it difficult or impossible to find a comparable population group that is not screened.

We propose to use a new measure, the number of interval cancers out of the total number of cancers, called the interval cancer ratio, as an alternative measure for the burden of interval cancers in an organized mammography screening programme. We seek to validate this new measure by comparing it to the old measure, the proportional interval cancer rate.

Method:

We did a systematic review and included studies: 1) covering a service screening programme, 2) with inclusion of women aged 50-69 years, 3) that contained observed data, papers based on modeling only were excluded, 4) that contained data on number of interval cancers and number of women screened, or on interval cancers rate, and 5) that contained information on estimated breast cancer incidence rate of the background population. This resulted in 6 papers describing 12 mammography screening programmes.

Results:

The IC- ratio in studies including only initial screens, varied from 0.13 to 0.32 while the proportional interval cancer rate varied from 0.24 to 0.55 in the same studies. In studies including only subsequent screens the IC-ratio varied from 0.21 to 0.47 with a proportional interval cancer rate of 0.26 to 0.67. One study with mixed initial and subsequent screens with a majority of initial screens had an IC-ratio of 0.18, whereas the proportional interval cancer rate was 0.33. In the study with a majority of subsequent screens had an IC-ratio was 0.32 and the proportional interval cancer rate was 0.67.

There is a strong linear relationship between the interval cancer ratio and the proportional interval cancer rate in initial screens. In subsequent screens the trend is linear but is less obvious.

Conclusion:

Our main aim with this study was to propose and validate the interval cancer ratio as an alternative measure for the burden of interval cancers. The new measure seems to capture the burden of interval cancers just as well or better than the old measure, without the need for increasingly difficult estimations of background incidence, which makes it a more accessible tool when evaluating mammography screening programme performance.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-04-03.

Specificity and stability of the Acromyrmex-Pseudonocardia symbiosis

The stability of mutualistic interactions is likely to be affected by the genetic diversity of symbionts that compete for the same functional niche. Fungus-growing (attine) ants have multiple complex symbioses and thus provide ample opportunities to address questions of symbiont specificity and diversity. Among the partners are Actinobacteria of the genus Pseudonocardia that are maintained on the ant cuticle to produce antibiotics, primarily against a fungal parasite of the mutualistic gardens. The symbiosis has been assumed to be a hallmark of evolutionary stability, but this notion has been challenged by culturing and sequencing data indicating an unpredictably high diversity. We used 454 pyrosequencing of 16S rRNA to estimate the diversity of the cuticular bacterial community of the leaf-cutting ant Acromyrmex echinatior and other fungus-growing ants from Gamboa, Panama. Both field and laboratory samples of the same colonies were collected, the latter after colonies had been kept under laboratory conditions for up to 10 years. We show that bacterial communities are highly colony-specific and stable over time. The majority of colonies (25/26) had a single dominant Pseudonocardia strain, and only two strains were found in the Gamboa population across 17 years, confirming an earlier study. The microbial community on newly hatched ants consisted almost exclusively of a single strain of Pseudonocardia while other Actinobacteria were identified on older, foraging ants in varying but usually much lower abundances. These findings are consistent with recent theory predicting that mixtures of antibiotic-producing bacteria can remain mutualistic when dominated by a single vertically transmitted and resource-demanding strain.

Dynamic Wolbachia prevalence in Acromyrmex leaf-cutting ants: potential for a nutritional symbiosis

Wolbachia are renowned as reproductive parasites, but their phenotypic effects in eusocial insects are not well understood. We used a combination of qrt-PCR, fluorescence in situ hybridization and laser scanning confocal microscopy to evaluate the dynamics of Wolbachia infections in the leaf-cutting ant Acromyrmex octospinosus across developmental stages of sterile workers. We confirm that workers are infected with one or two widespread wsp genotypes of Wolbachia, show that colony prevalence is always 100% and characterize two rare recombinant genotypes. One dominant genotype is always present and most abundant, whereas another only proliferates in adult workers of some colonies and is barely detectable in larvae and pupae. An explanation may be that Wolbachia genotypes compete for host resources in immature stages while adult tissues provide substantially more niche space. Tissue-specific prevalence of the two genotypes differs, with the rarer genotype being over-represented in the adult foregut and thorax muscles. Both genotypes occur extracellularly in the foregut, suggesting an unknown mutualistic function in worker ant nutrition. Both genotypes are also abundant in the faecal fluid of the ants, suggesting that they may have extended functional phenotypes in the fungus garden that the ants manure with their own faeces.

Changes in the epidemiology of acute appendicitis and appendectomy in Danish children 1996-2004

PURPOSE

Aim of the study was to describe changes in the epidemiology of acute appendicitis in Danish children between 0-19 years of age for the period 1996-2004.

METHODS

The study was based on discharge diagnoses taken from the Danish National Patient Registry of all 28 274 patients with a diagnosis of acute uncomplicated or complicated appendicitis, and/or a registered procedure code of appendectomy. These data were computed together with data on the background population, and incidences were calculated.

RESULTS

A significant decrease in the incidence of acute uncomplicated appendicitis was found for all age groups (range, 13-36%). The decrease was present for both sexes, but most prominent in girls. The incidence of complicated acute appendicitis decreased by 10%.

CONCLUSION

The incidence of acute appendicitis is declining. The incidence of uncomplicated appendicitis appears to be declining more rapidly than that of complicated appendicitis. This finding does not necessarily imply poorer management of the disease, but-as suggested by others-could be due to different behaviours of uncomplicated and complicated appendicitis.

Peanut cross-reacting allergens in seeds and sprouts of a range of legumes

BACKGROUND

Recently, peanut-allergic patients have reported symptoms upon ingestion of bean sprouts produced from various legumes.

OBJECTIVE

This study was designed to identify immunoreactivity to seeds and sprouts of legumes other than peanut in sera from peanut-allergic patients.

METHODS

Crude protein extracts of seeds and sprouts (comprising cotelydons and hypocotyls/epicotyls) of peanut, soybean, green pea, blue lupine, mung bean, alfalfa, broad bean, and azuki bean were prepared. The reactivity of sera from 10 peanut-allergic patients to these extracts was analysed by indirect histamine release (HR), enzyme-allergosorbent test (EAST), EAST inhibition, and Western blots. Skin prick tests (SPTs) were performed on the patients with fresh legume seeds as well as four commercial legume sprouts, and food challenges with soybean, pea, and lupine were performed on a subgroup of the patients.

RESULTS

All legume seeds and commercial sprouts induced positive SPTs in some of the patients. Indirect HR experiments indicated an extensive co-reactivity between peanut and the legumes, and cross-reactivity was observed for soybean, pea, and lupine seeds as well as lupine hypocotyls in EAST inhibition experiments. Of the 16 protein extracts, soybean, pea, and lupine seed extracts produced visible bands in Western blots.

CONCLUSION

The symptoms reported by peanut-allergic patients after legume sprout intake might be caused by cross-reactivity of peanut-specific antibodies. The intake of raw legume sprouts might cause symptoms in peanut-allergic patients.

Genetic analysis of resistance to yellow rust in hexaploid wheat using a mixture model for multiple crosses

DNA-based molecular markers have been used in numerous studies for tagging specific genes in wheat for subsequent use in marker-assisted selection. Usually in plant breeding, procedures for mapping genes are based on analysis of a single segregating population. However, breeding programmes routinely evaluate large numbers of progeny derived from multiple-related crosses with some parental lines shared. In most such related crosses, the number of progeny is quite small. Thus, statistical techniques for detecting quantitative trait loci (QTLs) using data from conventional multi-cross breeding programmes are interesting. The objective of this study is to present a mixture model for QTL mapping in crosses of multiple inbred varieties with non-normal phenotype distributions and to use this model to map QTLs for yellow rust resistance in elite wheat breeding material. Three doubled haploid populations consisting of 41, 42 and 55 lines, respectively, originating from four parental varieties were studied. Multi-cross QTL analysis with three specific pathogen isolates of Puccinia striiformis f. sp. tritici and a mixture of the isolates revealed QTLs for resistance at four different genomic locations. These QTLs were found on chromosome 2AL, 2AS, 2BL and 6BL and explained between 21 and 41% of the phenotypic variation. Two of these QTLs, one on the long arm of chromosome 2A and one on the short arm of chromosome 2A were identical to the known yellow rust resistance genes Yr32 and Yr17, respectively, whereas the QTLs located on the long arms of chromosomes 2B and 6B may reflect types of resistance to yellow rust, which have not previously been mapped.

Cross-reactivity to eel, eelpout and ocean pout in codfish-allergic patients

Fish allergy is one of the most common food allergies in both children and adults and patients with allergic reactions to one fish species have in many cases been given the advice to avoid all fish, without further evaluation. The possible common reactivity between different fish species is not well studied. Because of this and a possible exploitation of fish species hitherto not much used in the Scandinavian diet ocean pout, eelpout and eel were evaluated. We examined the serological and biological cross-reactivity of these species in double-blind challenged-confirmed codfish-allergic patients using CAP, Maxisorp-radio allergosorbent test (RAST) inhibition, western blot, skin prick test (SPT) and histamine release (HR). All 18 codfish allergic patients had specific IgE to ocean pout, eelpout and eel determined by Maxisorp-RAST. All four fish species could induce basophil HR using blood from 16 of 18 patients and all patients tested reacted in SPT. This study demonstrates that patients with a verified clinical allergy to codfish in a high frequency express biological cross-reactivity to other fish species. By RAST inhibition this common reactivity was shown to be a true cross-reactivity.

Field evaluation of emmer wheat-derived synthetic hexaploid wheat for resistance to Russian wheat aphid (Homoptera: Aphididae)

Broadening the genetic base for resistance to Russian wheat aphid, Diuraphis noxia (Mordvilko) (Homoptera: Aphididae), in bread wheat, Triticum aestivum L., is desirable. To date, identified Russian wheat aphid resistance genes are either located to the D chromosomes or to rye translocation of wheat, and resistance derived from the A or B genomes of tetraploid Triticum spp. would therefore be highly beneficial. Fifty-eight synthetic hexaploid wheat, derived from interspecific crosses of Triticum dicoccum Schrank. and Aegilops tauschii (Coss.) Schmal. and their parents were evaluated for resistance to Russian wheat aphid under field conditions. Plots infested with aphids were compared with plots protected with insecticides. The T. dicoccum parents were highly resistant to Russian wheat aphids, whereas the Ae. tauschii parents were susceptible. Resistance levels observed in the synthetic hexaploids were slightly below the levels of their T. dicoccum parents when a visual damage scale was used. but no major resistance suppression was observed among the synthetics. Russian wheat aphid infestation on average reduced plant height and kernel weight at harvest in the synthetic hexaploids and the T. dicoccum parents by 3-4%, whereas the susceptible control 'Seri M82' suffered losses of above 20%. Because resistance in the synthetic hexaploid wheat is derived from their T. dicoccum parent, resistance gene(s) must be located on the A and/or B genomes. They must therefore be different from previously identified Russian wheat aphid resistance genes, which have all been located on the D genome of wheat or on translocated segments.

Field evaluation of emmer wheat-derived synthetic hexaploid wheat for resistance to Russian wheat aphid (Homoptera: Aphididae)

Broadening the genetic base for resistance to Russian wheat aphid, Diuraphis noxia (Mordvilko) (Homoptera: Aphididae), in bread wheat, Triticum aestivum L., is desirable. To date, identified Russian wheat aphid resistance genes are either located to the D chromosomes or to rye translocation of wheat, and resistance derived from the A or B genomes of tetraploid Triticum spp. would therefore be highly beneficial. Fifty-eight synthetic hexaploid wheat, derived from interspecific crosses of Triticum dicoccum Schrank. and Aegilops tauschii (Coss.) Schmal. and their parents were evaluated for resistance to Russian wheat aphid under field conditions. Plots infested with aphids were compared with plots protected with insecticides. The T. dicoccum parents were highly resistant to Russian wheat aphids, whereas the Ae. tauschii parents were susceptible. Resistance levels observed in the synthetic hexaploids were slightly below the levels of their T. dicoccum parents when a visual damage scale was used. but no major resistance suppression was observed among the synthetics. Russian wheat aphid infestation on average reduced plant height and kernel weight at harvest in the synthetic hexaploids and the T. dicoccum parents by 3-4%, whereas the susceptible control 'Seri M82' suffered losses of above 20%. Because resistance in the synthetic hexaploid wheat is derived from their T. dicoccum parent, resistance gene(s) must be located on the A and/or B genomes. They must therefore be different from previously identified Russian wheat aphid resistance genes, which have all been located on the D genome of wheat or on translocated segments.

Quantitative trait loci affecting plant regeneration from protoplasts of Brassica oleracea

Quantitative trait loci (QTLs) controlling the plant-regeneration ability of Brassica oleracea protoplasts were mapped in a population of 128 F(2) plants derived from a cross between the high-responding, rapid-cycling line and a low-responding, broccoli breeding line of B. oleracea. A modified bulked segregant analysis with AFLP markers identified two QTLs for plant regeneration. In a multiple regression analysis, the two QTLs explained 83% of the total genetic variation for regeneration recorded 15 weeks after initial transfer of microcalli to regeneration medium. Both QTLs showed additive effects, and the alleles contributing to the high regeneration frequencies were derived from the high-responding, rapid-cycling line. Using microsatellites with known location, the two QTLs were mapped to linkage groups O2 and O9 on the map published by Sebastian et al. [(2000) Theor Appl Genet 100:75-81] or to chromosomes C8 and C7 on the map published by Saal et al. [(2001) Theor Appl Genet 102:695-699]. QTLs for the early flowering trait of the rapid-cycling parent have previously been mapped to the same two linkage groups. Association between flowering time and regeneration ability was, however, not found in the present material, indicating that plant-regeneration ability can be transferred between cultivars independently of the early flowering trait. The detection of two major QTLs for plant regeneration in B. oleracea may provide the initial step towards the identification of markers suitable for marker-assisted selection of regeneration ability.

Characterization of greenbug (Homoptera: Aphididae) resistance in synthetic hexaploid wheats

Twelve greenbug (Schizaphis graminum (Rondani)) biotype E-resistant synthetic hexaploid wheats synthesized by crossing Triticum dicoccum Schrank. and Aegilops tauschii (Coss.) Schmal. were evaluated for the three known insect resistance categories, including antibiosis, anti-xenosis, and tolerance. Different methods were evaluated for calculating antibiosis and tolerance. Calculating intrinsic rate of population increase and measuring leaf chlorophyll content with a SPAD chlorophyll meter proved to be time- and labor-efficient for antibiosis and tolerance determination, respectively. The resistance in all synthetic hexaploids proved to be the result of a combination of antibiosis, antixenosis, and tolerance, which makes them valuable sources of greenbug resistance. To assist plant breeders in selecting the best germplasm for greenbug resistance, a plant resistance index was created that revealed differences among the synthetic hexaploid wheats.

Analysis of potential duplicates in barley gene bank collections using re-sampling of microsatellite data

Redundant duplication among putative Nordic spring barley material held at 12 gene banks worldwide was studied using 35 microsatellite primer pairs covering the entire barley genome. These microsatellite markers revealed an average of 7.1 alleles per locus, and a range of 1 to 17 different alleles per locus. Similarity of accession name was initially used to partition the 174 repatriated accessions into 36 potential duplicate groups, and one group containing 36 apparently unique or unrelated accessions. This partitioning was efficient to produce a distribution of mainly small average genetic distances within potential duplicate groups compared to distances from the group of unique accessions. However, comparisons within potential duplicate groups still contained large genetic distances of the same size as distances between unique accessions indicating classification errors. A bootstrap approach based on re-sampling of both microsatellite markers and alleles within marker loci was used to test for homogeneity within potential duplicate groups. The test was used in each group for sequential elimination of accessions with a significantly large average genetic distance to identify a homogeneous group. Such genetically homogeneous groups of two or more accessions were identified in 22 among the 36 potential duplicate groups studied. Results from the genetic analysis of some potential duplicate groups supported previous conclusions based on passport data through inclusion of the historically most-original accession in the genetically homogeneous group. In other potential duplicate groups the apparently most-original accession according to passport data was not included in the homogeneous set of accessions, indicating that this most-original accession does not have duplicate accessions in the group. During the present study the largest average genetic distance accepted in any homogeneous group was smaller than the smallest distance declared significant in any group, with a threshold average genetic distance of approximately 0.14. The results are discussed with respect to the identification of duplicate accessions within potential duplicate groups, as well as the elimination of genetic off types in such groups. Furthermore, large barley gene bank collections may be screened for potential duplicates with genetic distances below the suggested threshold of 0.14.

Expression and suppression of resistance to greenbug (Homoptera: Aphididae) in synthetic hexaploid wheats derived from Triticum dicoccum x Aegilops tauschii crosses

Fifty-eight synthetic hexaploid wheats, developed by crossing Triticum dicoccum Schrank. and Aegilops tauschii (Coss.) Schmal., were evaluated at the seedling stage, together with their parents, for resistance to greenbug (Schizaphis graminum Rondani) under greenhouse conditions. Seedlings of different synthetic hexaploids showed large phenotypic differences for resistance. All the T. dicoccum parents were susceptible, while high levels of resistance were observed in some of the Ae. tauschii parents. Of the synthetic hexaploids derived from resistant Ae. tauschii parents, a high proportion (76%) showed levels of resistance to the greenbug biotype used that were comparable to those of the resistant parent. While there were clear indications of the presence of suppressor genes for greenbug resistance in the A and/or B genomes of T. dicoccum in some synthetics, positive epistatic interaction was also found in synthetic hexaploids with higher levels of resistance than that of either parent. Resistance from different Ae. tauschii accessions was expressed differently when crossed with the same T. dicoccum, indicating diversity among the resistance genes present in the test synthetic hexaploid wheats. Based on resistance reactions, the genes conferring greenbug resistance in these synthetic hexaploids are probably different from resistance genes previously transferred to wheat from Ae. tauschii.

Expression and suppression of resistance to greenbug (Homoptera: Aphididae) in synthetic hexaploid wheats derived from Triticum dicoccum x Aegilops tauschii crosses

Fifty-eight synthetic hexaploid wheats, developed by crossing Triticum dicoccum Schrank. and Aegilops tauschii (Coss.) Schmal., were evaluated at the seedling stage, together with their parents, for resistance to greenbug (Schizaphis graminum Rondani) under greenhouse conditions. Seedlings of different synthetic hexaploids showed large phenotypic differences for resistance. All the T. dicoccum parents were susceptible, while high levels of resistance were observed in some of the Ae. tauschii parents. Of the synthetic hexaploids derived from resistant Ae. tauschii parents, a high proportion (76%) showed levels of resistance to the greenbug biotype used that were comparable to those of the resistant parent. While there were clear indications of the presence of suppressor genes for greenbug resistance in the A and/or B genomes of T. dicoccum in some synthetics, positive epistatic interaction was also found in synthetic hexaploids with higher levels of resistance than that of either parent. Resistance from different Ae. tauschii accessions was expressed differently when crossed with the same T. dicoccum, indicating diversity among the resistance genes present in the test synthetic hexaploid wheats. Based on resistance reactions, the genes conferring greenbug resistance in these synthetic hexaploids are probably different from resistance genes previously transferred to wheat from Ae. tauschii.

Allergenic components of a novel food, Micronesian nut Nangai (Canarium indicum), shows IgE cross-reactivity in pollen allergic patients

BACKGROUND

New foods may present a risk for food hypersensitive patients. Several examples exist of allergic reactions caused by cross-reactive plant-derived foods, and new foods should be scrutinised before introducing them to the market. We have evaluated the clinical and serological relevance of cross-reactivity between Nangai and pollen allergens.

METHODS

Cross-reactivity was examined with Maxisorp RAST (radioallergosorbent test), RAST inhibition and Western blot, using sera from patients allergic to grass, birch and mugwort pollen. None of the patients reported having seen or eaten Nangai previously. To determine the biological and clinical relevance of the cross-reactivity, histamine release (HR) test, skin prick test (SPT) and food challenge were used.

RESULTS

There was prevalence for reactivity against Nangai in the group of pollen allergic patients. This cross-reactivity seems to be related--at least in part--to carbohydrate epitopes. Three out of 12 patients tested with Nangai were positive upon open challenge, but using double blind placebo controlled food challenge (DBPCFC) this could not be confirmed in two patients. The biological effects of Nangai on allergic patients were confirmed using HR and SPT.

CONCLUSION

The Nangai specific IgE found among pollen allergic patients addresses the need for control of new or changed foods before introduction to the market.

Geophysics. Longitudinal variation in springtime ozone trends

Satellite measurements indicate that mid-latitude ozone depletion in the Northern Hemisphere spring during 1979-97 was worst over Europe and Russia. Here we show that these longitudinal differences in ozone trends are due to a combination of decadal variations in the circulation and transport of ozone-depleted air from the polar vortex. Any increase in ozone depletion in the polar vortex as a result of future cooling of the stratosphere would therefore be particularly bad over Europe and Russia.

Cytodifferentiation and transformation of embryogenic callus lines derived from anther culture of wheat

Three types of callus tissues established from anther culture of eleven doubled haploid (DH) lines of wheat (Triticum aestivum L.) were evaluated for their ability in enhancing friable embryogenic (Type II) culture differentiation and genetic transformation. Differences between types of callus inocula were highly significant (P < 0.001), suggesting that the quality of the initial callus explant is of profound importance in encouraging the proliferation of Type II cultures. Other factors found to be crucial included weekly subculture of friable embryogenic callus tissues on a maintenance medium containing 30 microM dicamba and a predominance of amino-acid nitrogen supplement. Transfer and integration of the beta-glucuronidase gene was also affected by the type of inoculum when suitable embryogenic cell cultures were transformed using silicon carbide whiskers and high velocity microprojectiles. Expression of the hygromycin phosphotransferase selectable marker gene sequence was confirmed in all the stably transformed cell lines maintained on selection media containing lethal levels of hygromycin. Comparatively, there were differences in the frequency of regenerable, transgenic clonal segments between whisker-treated and microprojectile bombarded tissues mainly as a result of the fact that cultures vortexed with whiskers were more capable of post-treatment cell proliferation and embryo differentiation than those bombarded with cDNA-coated microprojectiles. Conditions for obtaining these results are outlined and discussed in relation to the suitability of the two transformation strategies for producing transgenic cell aggregates of wheat.

[Chlamydia pneumoniae]

Chlamydia are obligate intracellular bacteria with a biphasic life cycle. In 1986 a new species of Chlamydiae, Chlamydia psittaci TWAR was discovered, later named Chlamydia pneumoniae. C. pneumoniae is probably an important pathogen causing respiratory tract infections in man, ranging from subclinical infection to life threatening pneumonia. Infections can occur in epidemics. Furthermore, associations between C. pneumoniae infection and coronary artery disease, lethal myocarditis and sarcoidosis have been suggested. The current diagnostic method is based on detection of specific antibodies against C. pneumoniae in blood. Macrolides or tetracyclines are the drugs of choice for treatment of C. pneumoniae infection.

Nuclear genes affecting percentage of green plants in barley (Hordeum vulgare L.) anther culture

The genetics behind response in barley anther culture was studied with 22 reciprocal and one single: cross between three varieties with high and four varieties with low capacity for green plant formation. Effects of genotypes dominated embryo formation and percentages of green plants, accounting for 62 and 76% of total variation, respectively, with almost no genetic effect on the ability to regenerate plants from pollen embryos. Nuclear genes could explain all genotype effects in this plant material, since no reciprocal effects were indicated. The three parents with high and the four parents with low capacity for green plant formation formed two phenotypically homogeneous groups, producing 27-52% and 0-7% green plants, respectively. Genetic variation within hybrids for both embryo and green plant formation could be explained completely by general combining ability (GCA). The results are discussed with respect to a previous similar study in hexaploid wheat and the reported existence of DNA deletions in the plastid genomes in albino plants from anther culture of wheat and barley.

[The polymerase chain reaction used in microbiologic diagnosis]

Among the new DNA technological methods for microbiological diagnosis, the most promising seems to be the polymerase chain reaction (PCR). The sensitivity of the method is approximately 100% and the specificity is between 90% and 100%, depending on the availability of an already existing test sufficient for comparison. The PCR is able to detect only one microorganism in clinical samples. Because of this high sensitivity, contamination of samples is one of the major problems. After certain preparation procedures, the method can be used on different kinds of human sample material. The PCR could be used for detection of a microorganism, for detection of a single gene (toxin gene) or for typing of microorganisms. It is expected that, in the immediate future PCR will be a prominent part of the methods used in microbiological diagnosis.

Nuclear genes affecting albinism in wheat (Triticum aestivum L.) anther culture

Inheritance of the ability to respond in wheat anther culture was studied from 6×2 reciprocal crosses between six varieties with high and two varieties with low capacity for green plant formation and their parents, replicated in two environments. Effects of genotypes dominated embryo formation and percentages of green plants, accounting for 78.4% and 85.4% of total variation, respectively, while smaller genetic effects were indicated for regeneration. Nuclear genes could explain almost all the genotype effects in this material. Embryo formation showed heterosis over high parent for 5 of the 12 hybrids, while percentages of green plants from the hybrids were intermediate to the parents. General Combining Ability (GCA) could explain 78.8% of the variation for embryo formation among the hybrids, whereas differences in percentage of green plants were dominated by Specific Combining Ability (SCA), accounting for 67.9% of hybrid variation. A positive correlation (r=0.81(**)) was observed between the genetic capacity for regeneration and green plant formation. Analysis of covariance indicated that effects causing GCA for green plant formation were mainly responsible for this correlation. A regression model with two parallel lines divided the six parent lines with high green plant formation into three groups with respect to their reactions with the two testers. The results are discussed with regard to possible involvement of two sets of nuclear genes affecting the percentage of green plants obtained in wheat anther culture: one set consisting of mainly additive effects affecting green plant percentage through an initial effect on regeneration ability, and another set of two or a few more major genes with dominance or epistatic effects uncorrelated with regeneration.

Lateral and anterior instability in acute ankle distortion. A radiologic investigation

In a prospective consecutive investigation radiologic tests for lateral and anterior instability in acute ankle distortion were found to be reliable indications of lateral ligament ruptures. Arthrography of the ankle joint was used as reference. Absence of instability, however, gives little information as to the ligamental status. The size of this group constitutes a clinical problem. Better results are achieved by combining lateral and anterior instability tests. If only one test is used, the anterior instability test should be preferred. The results of the two tests bare no relation to the degree of ligament ruptures found at operation.

Ruptures of the lateral ligaments of the ankle. Clinical diagnosis

During the 11-month period 1 October 1977 to 31 August 1978 a total of 44 patients with acute supination trauma of the ankle were examined. The clinical findings were compared with the results of arthrography. This revealed that direct and indirect tenderness of the anterior talofibular ligament and calcaneofibular ligament respectively, combined with a greater than or equal to 4 cm swelling anteriorly and over the lateral malleolus, indicated a ligament injury with great likelihood. If some of the diagnostic signs are absent, most emphasis should be laid on the swelling over the lateral malleolus and on the direct and indirect tenderness of the calcaneofibular ligament. The talar-tilt test and examination for the drawer sign were of limited diagnostic value.

Rupture of the lateral ligaments of the ankle: operation or plaster cast? A propective study

The material comprises 444 patients, aged 12-50 years, with acute sprain of the ankle, seen over an 11-month period (1.10. 1977 to 31.8. 1978). Clinical examination showed no rupture of the ligaments in 53. Arthrography in the remaining patients revealed rupture of the lateral ligaments in 209 (in two-thirds of the anterior talofibular ligament and in one-third of the anterior talofibular as well as calcaneofibular ligament). Conservative treatment with a below-knee plaster cast for 5 weeks was employed in 107 patients, while 102 were treated surgically by suture of the ruptured ligament(s) and subsequently wore a below-knee plaster cast for 5 weeks. The follow-up 1 year after the accident was attended by 63 per cent of the patients. Good results were found in 76 per cent of those treated by plaster cast only and in 81 per cent of those treated by surgery. The difference is not statistically significant.