IL6 suppresses vaccine responses in neonates by enhancing IL2 activity on T follicular helper cells

The inability of neonates to develop CD4+FoxP3-CXCR5hiPD-1hi T follicular helper (TFH) cells contributes to their weak vaccine responses. In previous studies, we measured diminished IgG responses when IL-6 was co-injected with a pneumococcal conjugate vaccine (PCV) in neonatal mice. This is in sharp contrast to adults, where IL-6 improves vaccine responses by downregulating the expression of IL-2Rβ on TFH cells and protecting them from the inhibitory effect of IL-2. In this study, we found that splenic IL-6 levels rapidly increased in both adult and neonatal mice following immunization, but the increase in neonatal mice was significantly more than that of adult mice. Moreover, immunized neonatal TFH cells expressed significantly more IL-2 as well as its receptors, IL-2Rα and IL-2Rβ, than the adult cells. Remarkably, IL-6 co-injection with PCV vaccine further increased the production of IL-2 and the expression of its receptors by neonatal TFH cells, whereas excess IL-6 had totally opposite effect in immunized adult mice. Underscoring the role of IL-6 in activating the IL-2 mediated suppression of vaccine responses, immunization of IL-6 knock-out neonates led to improved antibody responses accompanied by expanded TFH cells as well as lower levels of IL-2 and IL-2 receptors on TFH cells. Moreover, CpG containing PCV improved TFH response in neonates by suppressing the expression of IL-2 receptors on TFH cells and inhibiting IL-2 activity. These findings unveil age-specific differences in IL-6 mediated vaccine responses and highlight the need to consider age-related immunobiological attributes in designing vaccines.

Virulence Profiles and Genome-Wide Association Study for Ascochyta lentis Isolates Collected from Australian Lentil-Growing Regions

Ascochyta lentis, the causal organism of Ascochyta blight (AB) of lentil (Lens culinaris), has been shown to produce an avirulence effector protein that mediates AB resistance in certain lentil cultivars. The two known forms of the effector protein were identified from a biparental mapping population between isolates that have reciprocal virulence on 'PBA Hurricane XT' and 'Nipper'. The effector AlAvr1-1 was described for the PBA Hurricane XT-avirulent isolate P94-24 and AlAvr1-2 characterized in the PBA Hurricane XT-virulent isolate AlKewell. Here, we performed a genome-wide association study to identify other loci associated with AB for a differential set of lentil cultivars from a diverse panel of isolates collected in the Australian lentil-growing regions from 2013 to 2020. The chromosome 3 AlAvr1 locus was strongly associated with the PBA Hurricane XT, 'Indianhead', and Nipper disease responses, but one other genomic region on chromosome 11 was also associated with the Nipper disease trait. Our results corroborate earlier work that identified the AlAvr1 locus for field-collected isolates that span the period before release and after widespread adoption of PBA Hurricane XT. A multiplex PCR assay was developed to differentiate the genes AlAvr1-1 and AlAvr1-2 to predict PBA Hurricane XT avirulence and pathotype designation in the diversity panel. Increasing numbers of the PBA Hurricane XT-virulent pathotype 2 isolates across that time indicate strong selection for isolates with the AlAvr1-2 allele. Furthermore, one other region of the A. lentis genome may contribute to the pathogen-host interaction for lentil AB.

Field Pea (Pisum sativum) Germplasm Screening for Seedling Ascochyta Blight Resistance and Genome-Wide Association Studies Reveal Loci Associated with Resistance to Peyronellaea pinodes and Ascochyta koolunga

Ascochyta blight is a damaging disease that affects the stems, leaves, and pods of field pea (Pisum sativum) and impacts yield and grain quality. In Australia, field pea Ascochyta blight is primarily caused by the necrotrophic fungal species Peyronellaea pinodes and Ascochyta koolunga. In this study, we screened 1,276 Pisum spp. germplasm accessions in seedling disease assays with a mix of three isolates of P. pinodes and 641 accessions with three mixed isolates of A. koolunga (513 accessions were screened with both species). A selection of three P. sativum accessions with low disease scores for either pathogen, or in some cases both, were crossed with Australian field pea varieties PBA Gunyah and PBA Oura, and recombinant inbred line populations were made. Populations at the F3:4 and F4:5 generation were phenotyped for their disease response to P. pinodes and A. koolunga, and genotypes were determined using the diversity arrays technology genotyping method. Marker-trait associations were identified using a genome-wide association study approach. Trait-associated loci were mapped to the published P. sativum genome assembly, and candidate resistance gene analogues were identified in the corresponding genomic regions. One locus on chromosome 2 (LG1) was associated with resistance to P. pinodes, and the 8 Mb genomic region contains 156 genes, two of which are serine/threonine protein kinases, putatively contributing to the resistance trait. A second locus on chromosome 5 (LG3) was associated with resistance to A. koolunga, and the 35 Mb region contains 488 genes, of which five are potential candidate resistance genes, including protein kinases, a mitogen-activated protein kinase, and an ethylene-responsive protein kinase homolog.

De Novo Long-Read Whole-Genome Assemblies and the Comparative Pan-Genome Analysis of Ascochyta Blight Pathogens Affecting Field Pea

Ascochyta Blight (AB) is a major disease of many cool-season legumes globally. In field pea, three fungal pathogens have been identified to be responsible for this disease in Australia, namely Peyronellaea pinodes, Peyronellaea pinodella and Phoma koolunga. Limited genomic resources for these pathogens have been generated, which has hampered the implementation of effective management strategies and breeding for resistant cultivars. Using Oxford Nanopore long-read sequencing, we report the first high-quality, fully annotated, near-chromosome-level nuclear and mitochondrial genome assemblies for 18 isolates from the Australian AB complex. Comparative genome analysis was performed to elucidate the differences and similarities between species and isolates using phylogenetic relationships and functional diversity. Our data indicated that P. pinodella and P. koolunga are heterothallic, while P. pinodes is homothallic. More homology and orthologous gene clusters are shared between P. pinodes and P. pinodella compared to P. koolunga. The analysis of the repetitive DNA content showed differences in the transposable repeat composition in the genomes and their expression in the transcriptomes. Significant repeat expansion in P. koolunga’s genome was seen, with strong repeat-induced point mutation (RIP) activity being evident. Phylogenetic analysis revealed that genetic diversity can be exploited for species marker development. This study provided the much-needed genetic resources and characterization of the AB species to further drive research in key areas such as disease epidemiology and host–pathogen interactions.

Phenotypic and Genotypic Diversity of Ascochyta fabae Populations in Southern Australia

Ascochyta fabae Speg. is a serious foliar fungal disease of faba bean and a constraint to production worldwide. This study investigated the phenotypic and genotypic diversity of the A. fabae pathogen population in southern Australia and the pathogenic variability of the population was examined on a differential set of faba bean cultivars. The host set was inoculated with 154 A. fabae isolates collected from 2015 to 2018 and a range of disease reactions from high to low aggressiveness was observed. Eighty percent of isolates collected from 2015 to 2018 were categorized as pathogenicity group (PG) PG-2 (pathogenic on Farah) and were detected in every region in each year of collection. Four percent of isolates were non-pathogenic on Farah and designated as PG-1. A small group of isolates (16%) were pathogenic on the most resistant differential cultivars, PBA Samira or Nura, and these isolates were designated PG-3. Mating types of 311 isolates collected between 1991 and 2018 were determined and showed an equal ratio of MAT1-1 and MAT1-2 in the southern Australian population. The genetic diversity and population structure of 305 isolates were examined using DArTseq genotyping, and results suggest no association of genotype with any of the population descriptors viz.: collection year, region, host cultivar, mating type, or PG. A Genome-Wide Association Study (GWAS) was performed to assess genetic association with pathogenicity traits and a significant trait-associated genomic locus for disease in Farah AR and PBA Zahra, and PG was revealed. The high frequency of mating of A. fabae indicated by the wide distribution of the two mating types means changes to virulence genes would be quickly distributed to other genotypes. Continued monitoring of the A. fabae pathogen population through pathogenicity testing will be important to identify any increases in aggressiveness or emergence of novel PGs. GWAS and future genetic studies using biparental mating populations could be useful for identifying virulence genes responsible for the observed changes in pathogenicity.

Reference genome assembly for Australian Ascochyta lentis isolate Al4

Ascochyta lentis causes ascochyta blight in lentil (Lens culinaris Medik.) and yield loss can be as high as 50%. With careful agronomic management practices, fungicide use, and advances in breeding resistant lentil varieties, disease severity and impact to farmers have been largely controlled. However, evidence from major lentil producing countries, Canada and Australia, suggests that A. lentis isolates can change their virulence profile and level of aggressiveness over time and under different selection pressures. In this paper, we describe the first genome assembly for A. lentis for the Australian isolate Al4, through the integration of data from Illumina and PacBio SMRT sequencing. The Al4 reference genome assembly is almost 42 Mb in size and encodes 11,638 predicted genes. The Al4 genome comprises 21 full-length and gapless chromosomal contigs and two partial chromosome contigs each with one telomere. We predicted 31 secondary metabolite clusters, and 38 putative protein effectors, many of which were classified as having an unknown function. Comparison of A. lentis genome features with the recently published reference assembly for closely related A. rabiei show that genome synteny between these species is highly conserved. However, there are several translocations and inversions of genome sequence. The location of secondary metabolite clusters near transposable element and repeat-rich genomic regions was common for A. lentis as has been reported for other fungal plant pathogens.

Current population structure and pathogenicity patterns of Ascochyta rabiei in Australia

Ascochyta blight disease, caused by the necrotrophic fungus Ascochyta rabiei, is a major biotic constraint to chickpea production in Australia and worldwide. Detailed knowledge of the structure of the pathogen population and its potential to adapt to our farming practices is key to informing optimal management of the disease. This includes understanding the molecular diversity among isolates and the frequency and distribution of the isolates that have adapted to overcome host resistance across agroecologically distinct regions. Thanks to continuous monitoring efforts over the past 6 years, a comprehensive collection of A. rabiei isolates was collated from the major Australian chickpea production regions. To determine the molecular structure of the entire population, representative isolates from each collection year and growing region have been genetically characterized using a DArTseq genotyping-by-sequencing approach. The genotyped isolates were further phenotyped to determine their pathogenicity levels against a differential set of chickpea cultivars and genotype-phenotype associations were inferred. Overall, the Australian A. rabiei population displayed a far lower genetic diversity (average Nei's gene diversity of 0.047) than detected in other populations worldwide. This may be explained by the presence of a single mating-type in Australia, MAT1-2, limiting its reproduction to a clonal mode. Despite the low detected molecular diversity, clonal selection appears to have given rise to a subset of adapted isolates that are highly pathogenic on commonly employed resistance sources, and that are occurring at an increasing frequency. Among these, a cluster of genetically similar isolates was identified, with a higher proportion of highly aggressive isolates than in the general population. The discovery of distinct genetic clusters associated with high and low isolate pathogenicity forms the foundation for the development of a molecular pathotyping tool for the Australian A. rabiei population. Application of such a tool, along with continuous monitoring of the genetic structure of the population will provide crucial information for the screening of breeding material and integrated disease management packages.

Agroinfiltration for transient gene expression and characterisation of fungal pathogen effectors in cool-season grain legume hosts

KEY MESSAGE

Modified pEAQ-HT-DEST1 vectors were used for agroinfiltration in legumes. We demonstrate protein expression and export in pea, lentil, and faba bean; however, the method for chickpea was not successful. Agroinfiltration is a valuable research method for investigating virulence and avirulence effector proteins from pathogens and pests, where heterologous effector proteins are transiently expressed in plant leaves and hypersensitive necrosis responses and other effector functions can be assessed. Nicotiana benthamiana is widely used for agroinfiltration and the characterisation of broad-spectrum effectors. The method has also been used in other plant species including field pea, but not yet developed for chickpea, lentil, or faba bean. Here, we have modified the pEAQ-HT-DEST1 vector for expression of 6 × histidine-tagged green-fluorescent protein (GFP) and the known necrosis-inducing broad-spectrum effector necrosis and ethylene-inducing peptide (Nep1)-like protein (NLP). Modified pEAQ-based vectors were adapted to encode signal peptide sequences for apoplast targeting of expressed proteins. We used confocal microscopy to assess the level of GFP expression in agroinfiltrated leaves. While at 3 days after infiltration in N. benthamiana, GFP was expressed at a relatively high level, expression in field pea and faba bean at the same time point was relatively low. In lentil, an expression level of GFP similar to field pea and faba bean at 3 days was only observed after 5 days. Chickpea leaf cells were transformed at low frequency and agroinfiltration was concluded to not be successful for chickpea. We concluded that the pEAQ vector is suitable for testing host-specific effectors in field pea, lentil, and faba bean, but low transformation efficiency limits the utility of the method for chickpea.

Identification of Novel Sources of Resistance to Ascochyta Blight in a Collection of Wild Cicer Accessions

Chickpea production is constrained worldwide by the necrotrophic fungal pathogen Ascochyta rabiei, the causal agent of Ascochyta blight (AB). To reduce the impact of this disease, novel sources of resistance are required in chickpea cultivars. Here, we screened a new collection of wild Cicer accessions for AB resistance and identified accessions resistant to multiple, highly pathogenic isolates. In addition to this, analyses demonstrated that some collection sites of C. echinospermum harbor predominantly resistant accessions, knowledge that can inform future collection missions. Furthermore, a genome-wide association study identified regions of the C. reticulatum genome associated with AB resistance and investigation of these regions identified candidate resistance genes. Taken together, these results can be utilized to enhance the resistance of chickpea cultivars to this globally yield-limiting disease.

Military Life Stressors, Family Communication and Satisfaction: Associations with Children's Psychosocial Outcomes

Families experience multiple stressors as a result of military service. The purpose of this study was to examine facets of military life and family factors that may impact child psychosocial and mental health functioning. Using baseline data from the Millennium Cohort Family Study, this study examined family demographics and composition (age, number of children), military life stressors (injury, family, and deployment stressors), family communication and satisfaction as assessed by the Family Adaptability and Cohesion Evaluation Scale-IV, parental social functioning assessed via the Short Form Health Survey-36, and child mental health and behavioral functioning (parental reports of clinician-diagnosed mental health conditions such as depression) and an adapted version of the Strengths and Difficulties Questionnaire. Injury- and family-related military stressors were significant indicators of heightened risk for child mental health conditions, whereas greater levels of parental social functioning and family satisfaction were associated with lower risk of child mental health conditions. Differential associations were found in child functioning when military-related variables (e.g., service component), sociodemographic, and family composition factors (number and age of the children in the home) were examined. These findings underscore the importance of examining the "whole child" within the broader ecological and military family context to understand factors associated with children's mental and behavioral health. The results from the present study highlight the complex relationships that may be at play, which, in turn, have considerable implications for the development of policies to support children and families encountering multiple stressors related to a parent's military service.

Characterization of Growth Morphology and Pathology, and Draft Genome Sequencing of Botrytis fabae, the Causal Organism of Chocolate Spot of Faba Bean (Vicia faba L.)

Chocolate spot is a major fungal disease of faba bean caused by the ascomycete fungus, Botrytis fabae. B. fabae is also implicated in botrytis gray mold disease in lentils, along with B. cinerea. Here we have isolated and characterized two B. fabae isolates from chocolate spot lesions on faba bean leaves. In plant disease assays on faba bean and lentil, B. fabae was more aggressive than B. cinerea and we observed variation in susceptibility among a small set of cultivars for both plant hosts. Using light microscopy, we observed a spreading, generalized necrosis response in faba bean toward B. fabae. In contrast, the plant response to B. cinerea was localized to epidermal cells underlying germinated spores and appressoria. In addition to the species characterization of B. fabae, we produced genome assemblies for both B. fabae isolates using Illumina sequencing. Genome sequencing coverage and assembly size for B. fabae isolates, were 27x and 45x, and 43.2 and 44.5 Mb, respectively. Following genome assembly and annotation, carbohydrate-active enzyme (CAZymes) and effector genes were predicted. There were no major differences in the numbers of each of the major classes of CAZymes. We predicted 29 effector genes for B. fabae, and using the same selection criteria for B. cinerea, we predicted 34 putative effector genes. For five of the predicted effector genes, the pairwise dN/dS ratio between orthologs from B. fabae and B. cinerea was greater than 1.0, suggesting positive selection and the potential evolution of molecular mechanisms for host specificity in B. fabae. Furthermore, a homology search of secondary metabolite clusters revealed the absence of the B. cinerea phytotoxin botrydial and several other uncharacterized secondary metabolite biosynthesis genes from B. fabae. Although there were no obvious differences in the number or proportional representation of different transposable element classes, the overall proportion of AT-rich DNA sequence in B. fabae was double that of B. cinerea.

The Association between Caregiver Substance Abuse and Mental Health Problems and Outcomes for Trauma-Exposed Youth

Trauma-exposed youth with impaired caregivers (i.e., due to substance use and/or mental health problems) may be at particular risk for negative outcomes. This study utilized data from the National Child Traumatic Stress Network Core Data Set to examine the impact of caregiver impairment on youth outcomes. Trauma-exposed youth with an impaired caregiver due to either: substance use (n = 498), mental health problems (n = 231), or both substance use and mental health problems (n = 305) were compared to youth without a reported impaired caregiver (n = 2282) to determine if impaired caregiver status is independently associated with increased likelihood of negative behavioral and mental health outcomes and service utilization after accounting for demographics and exposure to traumatic events. Youth with impaired caregivers compared to those without were more likely to display PTSD, emotional and behavioral problems, suicidality, self-injury, and substance abuse and had higher rates of service utilization (p < 0.05). Differential patterns were observed based on the type of caregiver impairment. Findings support the importance of family-centered assessment and intervention approaches for youth affected by trauma.

Near-infrared multispectral endoscopic imaging of deep artificial interproximal lesions in extracted teeth

BACKGROUND AND OBJECTIVE

A safer alternative method to radiographic imaging is needed. We present a multispectral near-infrared scanning fiber endoscope (nirSFE) for dental imaging which is designed to be the smallest imaging probe with near-infrared (NIR) imaging (1200-2000 nm).

MATERIALS AND METHODS

The prototype nirSFE is designed for wide-field forward viewing of scanned laser illumination at 1310, 1460, or 1550 nm. Artificial lesions with varying sizes and locations were prepared on proximal surfaces of extracted human teeth to examine capability and limitation of this new dental imaging modality. Nineteen artificial interproximal lesions and several natural occlusal lesions on extracted teeth were imaged with nirSFE, OCT, and microCT.

RESULTS

Our nirSFE system has a flexible shaft as well as a probe tip with diameter of 1.6 mm and a rigid length of 9 mm. The small form factor and multispectral NIR imaging capability enables multiple viewing angles and reliable detection of lesions that can extend into the dentin. Among nineteen artificial interproximal lesions, the nirSFE reflectance imaging operating at 1460-nm and OCT operating at 1310-nm scanned illumination exhibited high sensitivity for interproximal lesions that were closer to occlusal surface. Diagnosis from a non-blinded trained user by looking at real-time occlusal-side nirSFE videos indicate true positive rate of 78.9%. There were no false positives.

CONCLUSIONS

This study demonstrates that nirSFE may be used for detecting occlusal lesions and interproximal lesions located less than 4 mm under the occlusal surface. Major advantages of this imaging system include multiple viewing angles due to flexibility and small form factor, as well as the ability to capture real-time video. The multispectral nirSFE has the potential to be employed as a low-cost dental camera for detecting dental lesions without exposure to ionizing radiation. Lasers Surg. Med. 51:459-465, 2019. © 2019 Wiley Periodicals, Inc.

Near-Infrared Imaging of Artificial Enamel Caries Lesions with a Scanning Fiber Endoscope

Several studies have shown that near-infrared imaging has great potential for the detection of dental caries lesions. A miniature scanning fiber endoscope (SFE) operating at near-infrared (NIR) wavelengths was developed and used in this study to test whether the device could be used to discriminate demineralized enamel from sound enamel. Varying depths of artificial enamel caries lesions were prepared on 20 bovine blocks with smooth enamel surfaces. Samples were imaged with a SFE operating in the reflectance mode at 1310-nm and 1460-nm in both wet and dry conditions. The measurements acquired by the SFE operating at 1460-nm show significant difference between the sound and the demineralized enamel. There was a moderate positive correlation between the SFE measurements and micro-CT measurements, and the NIR SFE was able to detect the presence of demineralization with high sensitivity (0.96) and specificity (0.85). This study demonstrates that the NIR SFE can be used to detect early demineralization from sound enamel. In addition, the NIR SFE can differentiate varying severities of demineralization. With its very small form factor and maneuverability, the NIR SFE should allow clinicians to easily image teeth from multiple viewing angles in real-time.

IL-6 Impairs Vaccine Responses in Neonatal Mice

The inability of infants to mount proper follicular helper T (T_FH) cell response renders this age group susceptible to infectious diseases. Initial instruction of T cells by antigen presenting cells and subsequent differentiation into T_FH cells are controlled by T cell receptor signal strength, co-stimulatory molecules and cytokines such as IL-6 and IL-21. In immunized adults, IL-6 promotes T_FH development by increasing the expression of CXCR5 and the T_FH master transcription factor, B cell lymphoma 6. Underscoring the importance of IL-6 in T_FH generation, we found improved antibody responses accompanied by increased T_FH cells and decreased follicular regulatory helper T (T_FR) cells, a Foxp3 expressing inhibitory CD4⁺ T cell occupying the germinal center (GC), when a tetanus toxoid conjugated pneumococcal polysaccharide type 14 vaccine was injected in adult mice together with IL-6. Paradoxically, in neonates IL-6 containing PPS14-TT vaccine suppressed the already impaired T_FH development and antibody responses in addition to increasing T_FR cell population. Supporting the diminished T_FH development, we detected lower frequency of phospho-STAT-3⁺ T_FH in immunized neonatal T cells after IL-6 stimulation than adult cells. Moreover, IL-6 induced more phospho-STAT-3⁺ T_FR in neonatal cells than adult cells. We also measured lower expression of IL-6R on T_FH cells and higher expression on T_FR cells in neonatal cells than adult cells, a possible explanation for the difference in IL-6 induced signaling in different age groups. Supporting the flow cytometry findings, microscopic examination revealed the localization of T_reg cells in the splenic interfollicular niches of immunized adult mice compared to splenic follicles in neonatal mice. In addition to the limitations in the formation of IL-21 producing T_FH cells, neonatal mice GC B cells also expressed lower levels of IL-21R in comparison to the adult mice cells. These findings point to diminished IL-6 activity on neonatal T_FH cells as an underlying mechanism of the increased T_FR: T_FH ratio in immunized neonatal mice.

Impaired Caregiving, Trauma Exposure, and Psychosocial Functioning in a National Sample of Children and Adolescents

Impairments in Caregiving (ICG) secondary to mental illness and substance use have been linked to adverse outcomes in children. Little is known, however, about whether outcomes vary by type of ICG, exposure to co-occurring traumas, or mechanisms of maladaptive outcomes. Clinic-referred youth age 7-18 years (n = 3988) were compared on ICG history, demographics, trauma history, and mental health symptoms. Child trauma exposure was tested as a mediator of ICG and child symptoms. Youth with ICG were at heightened risk for trauma exposure, PTSD, internalizing symptoms, total behavioral problems, and attachment problems, particularly youth with multiple types of ICG. Effect sizes were moderate to large for PTSD, internalizing symptoms, and total behavioral problems. Number of trauma types mediated the relationship between ICG and child symptoms. ICG was related to trauma exposure within and outside the family context. Understanding these links has important implications for interrupting intergenerational trauma and psychopathology.

The Dissociative Subtype of Posttraumatic Stress Disorder (PTSD) Among Adolescents: Co-Occurring PTSD, Depersonalization/Derealization, and Other Dissociation Symptoms

OBJECTIVE

The purpose of this study was to examine the co-occurrence of posttraumatic stress disorder (PTSD) and dissociation in a clinical sample of trauma-exposed adolescents by evaluating evidence for the depersonalization/derealization dissociative subtype of PTSD as defined by the DSM-5 and then examining a broader set of dissociation symptoms.

METHOD

A sample of treatment-seeking, trauma-exposed adolescents 12 to 16 years old (N = 3,081) from the National Child Traumatic Stress Network Core Data Set was used to meet the study objectives. Two models of PTSD/dissociation co-occurrence were estimated using latent class analysis, one with 2 dissociation symptoms and the other with 10 dissociation symptoms. After model selection, groups within each model were compared on demographics, trauma characteristics, and psychopathology.

RESULTS

Model A, the depersonalization/derealization model, had 5 classes: dissociative subtype/high PTSD; high PTSD; anxious arousal; dysphoric arousal; and a low symptom/reference class. Model B, the expanded dissociation model, identified an additional class characterized by dissociative amnesia and detached arousal.

CONCLUSION

These 2 models provide new information about the specific ways PTSD and dissociation co-occur and illuminate some differences between adult and adolescent trauma symptom expression. A dissociative subtype of PTSD can be distinguished from PTSD alone in adolescents, but assessing a wider range of dissociative symptoms is needed to fully characterize adolescent traumatic stress responses.

Influence of multi-wavelength laser irradiation of enamel and dentin surfaces at 0.355, 2.94, and 9.4 μm on surface morphology, permeability, and acid resistance

OBJECTIVE

Ultraviolet (UV) and infrared (IR) lasers can be used to specifically target protein, water, and mineral, respectively, in dental hard tissues to produce varying changes in surface morphology, permeability, reflectivity, and acid resistance. The purpose of this study was to explore the influence of laser irradiation and topical fluoride application on the surface morphology, permeability, reflectivity, and acid resistance of enamel and dentin to shed light on the mechanism of interaction and develop more effective treatments.

METHODS

Twelve bovine enamel surfaces and twelve bovine dentin surfaces were irradiated with various combinations of lasers operating at 0.355 (Freq.-tripled Nd:YAG (UV) laser), 2.94 (Er:YAG laser), and 9.4 μm (CO₂ laser), and surfaces were exposed to an acidulated phosphate fluoride gel and an acid challenge. Changes in the surface morphology, acid resistance, and permeability were measured using digital microscopy, polarized light microscopy, near-IR reflectance, fluorescence, polarization sensitive-optical coherence tomography (PS-OCT), and surface dehydration rate measurements.

RESULTS

Different laser treatments dramatically influenced the surface morphology and permeability of both enamel and dentin. CO₂ laser irradiation melted tooth surfaces. Er:YAG and UV lasers, while not melting tooth surfaces, showed markedly different surface roughness. Er:YAG irradiation led to significantly rougher enamel and dentin surfaces and led to higher permeability. There were significant differences in acid resistance among the various treatment groups.

CONCLUSION

Surface dehydration measurements showed significant changes in permeability after laser treatments, application of fluoride and after exposure to demineralization. CO₂ laser irradiation was most effective in inhibiting demineralization on enamel while topical fluoride was most effective for dentin surfaces. Lasers Surg. Med. 49:913-927, 2017. © 2017 Wiley Periodicals, Inc.

Characterization of pathways involved in the suppression of T follicular helper cells in newborns

The immature immune system of newborns renders poor vaccine response. However, mechanisms of limited T follicular helper (Tfh)-mediated antibody production in newborns are largely unknown.

We found significantly more expression of the Tfh inhibitory genes associated with regulatory T cell (Treg) cells and IL-2 signaling in immunized newborn mice CD4+CXCR5+PD-1+Tfh cells than in adult mice. The IL-2-STAT5 signaling in CD4+CXCR5+PD-1+Foxp3+T follicular regulatory cells (Tfr) was hyperactive in newborns as compared to adults. Also, in newborns IL-6-STAT3 signaling was lower in Tfh cells but higher in Tfr cells compared to adult mice. Immunization did not elicit IL-21 expressing Tfh cells but when provided sufficient IL-21, in vitro cultured newborn T cells differentiated into Tfh-like cells. These data indicate that in newborns, dendritic cell-derived IL-6 signaling preferentially induces Treg cells to differentiate into Tfr cells, which in turn suppresses Tfh generation. Supporting this hypothesis, co-injection of newborn mice with conjugate type 14 pneumococcal polysaccharide vaccine together with IL-21 or anti-CD25 blocking antibody reduced Tfr/Tfh ratio and enhanced Tfh formation. While IL-21 elicited both IgG and IgA antibodies against vaccine, anti-CD25 antibody only improved IgA production, due in part to the elevated APRIL and TGF-β expression in T cells and fibroblast reticular cells. Since IL-21 acts both on T cells and B cells, improved IgG response in IL-21 injected mice is likely due to its direct effect on B cells.

These findings highlight the differences in the programming of IL-2 and IL-6 signaling in newborn and adult Tfh cells. These differences may be exploited in devising improved vaccines for infants.

Near-IR and CP-OCT imaging of suspected occlusal caries lesions

INTRODUCTION

Radiographic methods have poor sensitivity for occlusal lesions and by the time the lesions are radiolucent they have typically progressed deep into the dentin. New more sensitive imaging methods are needed to detect occlusal lesions. In this study, cross-polarization optical coherence tomography (CP-OCT) and near-IR imaging were used to image questionable occlusal lesions (QOC's) that were not visible on radiographs but had been scheduled for restoration on 30 test subjects.

METHODS

Near-IR reflectance and transillumination probes incorporating a high definition InGaAs camera and near-IR broadband light sources were used to acquire images of the lesions before restoration. The reflectance probe utilized cross-polarization and operated at wavelengths from 1,500 to 1,700 nm where there is an increase in water absorption for higher contrast. The transillumination probe was operated at 1,300 nm where the transparency of enamel is highest. Tomographic images (6 × 6 × 7 mm³ ) of the lesions were acquired using a high-speed swept-source CP-OCT system operating at 1,300 nm before and after removal of the suspected lesion.

RESULTS

Near-IR reflectance imaging at 1,500-1,700 nm yielded significantly higher contrast (P < 0.05) of the demineralization in the occlusal grooves compared with visible reflectance imaging. Stains in the occlusal grooves greatly reduced the lesion contrast in the visible range yielding negative values. Only half of the 26 lesions analyzed showed the characteristic surface demineralization and increased reflectivity below the dentinal-enamel junction (DEJ) in 3D OCT images indicative of penetration of the lesion into the dentin.

CONCLUSION

This study demonstrates that near-IR imaging methods have great potential for improving the early diagnosis of occlusal lesions. Lasers Surg. Med. 49:215-224, 2017. © 2017 Wiley Periodicals, Inc.

Activity assessment of root caries lesions with thermal and near-IR imaging methods

The purpose of this study was to evaluate thermal and near-infrared (NIR) reflectance imaging methods for the assessment of the activity of root caries lesions. In addition, changes in the lesion structure were monitored with polarization sensitive optical coherence tomography (PS-OCT). Artificial bovine and natural root caries lesions were imaged with PS-OCT, and their dehydration rate was measured with thermal and NIR cameras. The lesion activity of the natural root caries samples was also assessed by two clinicians by conventional means according to ICDAS II guidelines. The thickness of the highly mineralized transparent surface layer measured using PS-OCT increased and the area enclosed by the time-temperature curve, ΔQ, measured with thermal imaging decreased significantly with longer periods of remineralization in simulated dentin lesions, but the NIR reflectance intensity differences, ΔI, failed to show any significant relationship with the degree of remineralization. The PS-OCT algorithm for the automated assessment of remineralization successfully detected the highly mineralized surface layer on both natural and simulated lesions. Thermal imaging provided the most accurate diagnosis of root caries lesion activity. These results demonstrate that thermal imaging and PS-OCT may be ideally suited for the nondestructive root caries lesion activity during a clinical examination.

Influence of Multi-Wavelength Laser Irradiation of Enamel and Dentin Surfaces on Surface Morphology and Permeability

UV and IR lasers can be used to specifically target protein, water, and the mineral phase of dental hard tissues to produce varying changes in surface morphology. In this study, we irradiated enamel and dentin surfaces with various combinations of lasers operating at 0.355, 2.94, and 9.4 μm, exposed those surfaces to topical fluoride, and subsequently evaluated the influence of these changes on surface morphology and permeability. Digital microscopy and surface dehydration rate measurements were used to monitor changes in the samples overtime. The surface morphology and permeability (dehydration rate) varied markedly with the different laser treatments on enamel. On dentin, fluoride was most effective in reducing the permeability.

Near-infrared imaging of enamel hypomineralization due to developmental defects

The increasing prevalence of mild hypomineralization due to developmental defects on tooth surfaces poses a challenge for caries detection and caries risk assessment and reliable methods need to be developed to discriminate such lesions from active caries lesions that need intervention. Previous studies have demonstrated that areas of hypomineralization are typically covered with a relatively thick surface layer of highly mineralized and transparent enamel similar to arrested lesions. Seventy-six extracted human teeth with mild to moderate degrees of suspicious fluorosis were imaged using near-infrared reflectance and transillumination. Enamel hypomineralization was clearly visible in both modalities. However, it was difficult to distinguish hypomineralization due to developmental defects from caries lesions with contrast measurements alone. The location of the lesion on tooth coronal surface (i.e. generalized vs. localized) seems to be the most important indicator for the presence of enamel hypomineralization due to developmental defects.

Implications of Cancer Staging Uncertainties in Radiation Therapy Decisions

Introduction . Radiation therapy (RT) for cancer is a critical medical procedure that occurs in a complex environment involving numerous health professionals, hardware, software, and equipment. Uncertainties and potential incidents can lead to inappropriate administration of radiation to patients, with sometimes catastrophic consequences such as premature death or appreciably impaired quality of life. The authors evaluate the impact of incorrectly staging (i.e., estimation of extent of cancer) breast cancer patients and resulting inappropriate treatment decisions. Methods . The authors employ analytic and simulation methods in an influence-diagram framework to estimate the probability of incorrect staging and treatment decisions. As inputs, they use a combination of literature information on the accuracy and precision of pathology and tests as well as expert judgment. Sensitivity and value-of-information analyses are conducted to identify important uncertainties. Results and conclusions . The authors find a small but nontrivial probability that breast cancer patients will be incorrectly staged and thus may be subjected to inappropriate treatment. Results are sensitive to a number of variables, and some routinely used tests for metastasis have very limited information value. This work has implications for the methods used in cancer staging, and the methods are generalizable for quantitative risk assessment of treatment errors.

The triple-phase CT image appearance of post-irradiated livers

Objective To evaluate the sequential CT appearance of the liver after hepatic irradiation and to investigate the correlation between CT findings and radiation-induced hepatic injury.

Material and Methods: The triple-phase CT images of 18 patients with hepatocellular carcinomas (HCC) after hepatic irradiation were retrospectively reviewed (in total 41 CT studies). The high-dose region within the liver was defined as the area receiving more than 90% of the prescribed irradiation dose. The mean radiation dose was 55.5 Gy. Density changes and patterns of enhancement in the high-dose region were classified as three types: type I, constant low-density change in all phases; type II, low-density change in both pre-contrast and arterial phases, and iso-density change in the portal phase; type III, low- or iso-density change in the pre-contrast phase, low- or high-density change in the arterial phase, and persistent high-density change in the portal phase. The interval between completion of radiotherapy and the CT examinations ranged from 9 to 469 days, with a mean of 147 days.

Results: Nine of the 41 CT studies presented with type I, 9 with type II, and 16 with type III CT findings. The mean interval between completion of radiotherapy and the appearance of types I, II, and III CT findings were 74, 183, and 220 days, respectively. The interval was significantly shorter for type I findings than for type II and type III. The difference in interval was not significant between type II and type III. A type I finding with constant low-density change in the high-dose region of the liver was the most common pattern of CT findings within the first 3 months after hepatic irradiation. Either types II or III findings were frequently seen after 3 months.

Conclusion: The sequential CT appearance and the density changes may indicate correlation with the pathogenesis of veno-occlusive disease.

Near-IR transillumination and reflectance imaging at 1,300 nm and 1,500-1,700 nm for in vivo caries detection

INTRODUCTION

Several studies suggest that near-IR imaging methods at wavelengths longer than 1,300 nm have great potential for caries detection. In this study, the diagnostic performance of both near-IR transillumination and near-IR reflectance was assessed on teeth scheduled for extraction due to orthodontic treatment (n = 109 teeth on 40 test subjects).

METHODS

Three intra-oral near-IR imaging probes were fabricated for the acquisition of in vivo images using a high definition InGaAs camera and near-IR broadband light sources. Two transillumination probes provided occlusal and approximal images using 1,300 nm light which manifests the highest transparency in enamel. A third reflectance probe utilized cross-polarization and operated at wavelengths greater than 1,500 nm where water absorption is higher which reduces the reflectivity of sound tissues, significantly increasing lesion contrast. Teeth were collected after extraction and sectioned and examined with polarized light microscopy and microradiography which served as the gold standard. In addition, radiographs were taken of the teeth and the diagnostic performance of near-IR imaging was compared with radiography.

RESULTS

Near-IR imaging was significantly more sensitive (P < 0.05) than radiography for the detection of lesions on both occlusal and proximal surfaces.

CONCLUSION

Near-IR imaging methods are ideally suited for screening all tooth surfaces for carious lesions. Lasers Surg. Med. 48:828-836, 2016. © 2016 Wiley Periodicals, Inc.

Infrared Methods for Assessment of the Activity of Natural Enamel Caries Lesions

New diagnostic methods are needed for the accurate assessment of caries lesion activity to establish the need for surgical treatment. Detection of the highly mineralized surface layer that forms near the surface of the lesions as a result of remineralization is important for diagnosis of the lesion activity. Previous studies have demonstrated that novel imaging methods can be used to detect remineralization of artificial enamel caries lesions. In this paper, the activity of natural enamel caries lesions was assessed in-vitro via detection of the surface layer with PS-OCT and dehydration rate measurements with NIR reflectance and thermal imaging modalities. An automated approach for detecting the surface layer with PS-OCT yielded high sensitivity (= 0.79) and high specificity (= 0.93) with moderate correlation (R2 = 0.5920) with histology. Significant differences in dehydration rate measurements were found between the active and the arrested lesions using both the NIR reflectance and thermal imaging modalities. These results demonstrate that these novel imaging methods are ideally suited for nondestructive, noninvasive and quantitative measurement of lesion activity during a single clinical examination in real-time.

Clinical monitoring of smooth surface enamel lesions using CP-OCT during nonsurgical intervention

INTRODUCTION

Studies have shown that cross-polarization optical coherence tomography (CP-OCT) can be used to image the internal structure of carious lesions in vivo. The objective of this study was to show that CP-OCT can be used to monitor changes in the internal structure of early active carious lesions on smooth surfaces during non-surgical intervention with fluoride.

METHODS

Lesions on the smooth surfaces of teeth were imaged using CP-OCT on 17 test subjects. Lesion structural changes were monitored during fluoride varnish application at 6-week intervals for 30 weeks. The lesion depth (L_d ), integrated reflectivity (ΔR), and surface zone thickness (S_z ) were monitored.

RESULTS

A distinct transparent surface zone that may be indicative of lesion arrestment was visible in CP-OCT images on 62/63 lesions before application of fluoride varnish. The lesion depth and internal structure were resolved for all the lesions. The overall change in the mean values for L_d , ΔR, and S_z for all the lesions was minimal and was not significant during the study (P > 0.05). Only 5/63 lesions manifested a significant increase in S_z during intervention.

CONCLUSION

Even though it appears that most of the lesions manifested little change with fluoride varnish application in the 30 weeks of the study, CP-OCT was able to measure the depth and internal structure of all the lesions including the thickness of the important transparent surface zone located at the surface of the lesions, indicating that CP-OCT is ideally suited for monitoring lesion severity in vivo. Lasers Surg. Med. 48:915-923, 2016. © 2016 Wiley Periodicals, Inc.

Assessment of remineralized dentin lesions with thermal and near-infrared reflectance imaging

Accurate detection and measurement of the highly mineralized surface layer that forms on caries lesions is important for the diagnosis of lesion activity. Previous studies have demonstrated that optical imaging methods can be used to measure the degree of remineralization on enamel lesions. The purpose of this study was to determine if thermal and near-IR reflectance imaging could be used to assess the remineralization process in simulated dentin lesions. Artificial bovine (n=15) dentin lesions were prepared by immersion in a demineralization solution for 24 hours and they were subsequently placed in an acidic remineralization solution for up to 12 days. The samples were dehydrated using an air spray for 30 seconds and imaged using thermal and InGaAs cameras. The area enclosed by the time-temperature curve, ΔQ, from thermal imaging decreased significantly with longer periods of remineralization. However, near-IR reflectance intensity differences, ΔI, before and after dehydration failed to show any significant relationship with the degree of remineralization. This study shows that thermal imaging can be used for the assessment of the remineralization of dentin lesions.

Assessment of simulated lesions on primary teeth with near-infrared imaging

Previous studies have demonstrated that the structural changes on enamel due to demineralization and remineralization can be exploited through optical imaging methods such as QLF, thermal and NIR imaging. The purpose of this study is to investigate whether PS-OCT and NIR reflectance imaging can be utilized to assess lesion structure in artificial enamel lesions on the smooth surfaces of primary teeth exposed to fluoride. The smooth coronal surfaces of primary teeth (n=25) were divided into 4 windows: sound, demineralization, demineralization with remineralization and APF with demineralization. Windows were treated with either acidulated phosphate fluoride (APF) for 1 minute, a demineralization solution for 4 days, and/or an acidic remineralization solution for 12 days. The samples were imaged using PS-OCT, QLF and NIR reflectance at 1400-1700 nm wavelengths. This study demonstrated that both PS-OCT and NIR reflectance imaging were suitable for assessing lesion structure in the smooth surfaces of primary dentition.

Near-infrared imaging of secondary caries lesions around composite restorations at wavelengths from 1300-1700-nm

BACKGROUND AND OBJECTIVES

Current clinical methods for diagnosing secondary caries are unreliable for identifying the early stages of decay around restorative materials. The objective of this study was to access the integrity of restoration margins in natural teeth using near-infrared (NIR) reflectance and transillumination images at wavelengths between 1300 and 1700-nm and to determine the optimal NIR wavelengths for discriminating composite materials from dental hard tissues.

MATERIALS AND METHODS

Twelve composite margins (n=12) consisting of class I, II and V restorations were chosen from ten extracted teeth. The samples were imaged in vitro using NIR transillumination and reflectance, polarization sensitive optical coherence tomography (PS-OCT) and a high-magnification digital microscope. Samples were serially sectioned into 200-μm slices for histological analysis using polarized light microscopy (PLM) and transverse microradiography (TMR). Two independent examiners evaluated the presence of demineralization at the sample margin using visible detection with 10× magnification and NIR images presented digitally. Composite restorations were placed in sixteen sound teeth (n=16) and imaged at multiple NIR wavelengths ranging from λ=1300 to 1700-nm using NIR transillumination. The image contrast was calculated between the composite and sound tooth structure.

RESULTS

Intensity changes in NIR images at wavelengths ranging from 1300 to 1700-nm correlate with increased mineral loss measured using TMR. NIR reflectance and transillumination at wavelengths coincident with increased water absorption yielded significantly higher (P<0.001) contrast between sound enamel and adjacent demineralized enamel. In addition, NIR reflectance exhibited significantly higher (P<0.01) contrast between sound enamel and adjacent composite restorations than visible reflectance.

SIGNIFICANCE

This study shows that NIR imaging is well suited for the rapid screening of secondary caries lesions.

Polyvictimization: Latent profiles and mental health outcomes in a clinical sample of adolescents

OBJECTIVE

Exposure to multiple traumatic events (polyvictimization) is a reliable predictor of deleterious health outcomes and risk behaviors in adolescence. The current study extends the literature on the prevalence and consequences of adolescent trauma exposure by (a) empirically identifying and characterizing trauma exposure profiles in a large, ethnically diverse, multi-site, clinical sample of adolescents, and (b) evaluating relations among identified profiles with demographic characteristics and clinical correlates.

METHOD

Data from the National Child Traumatic Stress Network Core Data Set were used to identify and characterize victimization profiles using latent class analysis in a sample of 3,485 adolescents (ages 13-18, 63% female, 35.7% White, 23.2% Black/African American, 35.0% Hispanic/Latino). Multiple measures of psychological distress and risk behaviors were evaluated as covariates of trauma exposure classes.

RESULTS

Five trauma exposure classes, or profiles, were identified. Four classes-representing approximately half the sample-were characterized by polyvictimization. Polyvictimization classes were differentiated on number of trauma types, whether emotional abuse occurred, and whether emotional abuse occurred over single or multiple developmental epochs. Unique relations with demographic characteristics and mental health outcomes were observed.

DISCUSSION

Results suggest polyvictimization is not a unidimensional phenomenon but a diverse set of trauma exposure experiences with unique correlates among youth. Further research on prevention of polyvictimization and mechanisms linking chronic trauma exposure, gender, and ethnicity to negative outcomes is warranted.

Assessment of remineralization via measurement of dehydration rates with thermal and near-IR reflectance imaging

OBJECTIVES

Previous studies have demonstrated that the optical changes due to the loss of water from porous lesions can be exploited to assess lesion severity with QLF, thermal and near-IR imaging. Since arrested lesions are less permeable to water due to the highly mineralized surface layer, changes in the rate of water loss can be related to changes in lesion structure. The purpose of this study was to investigate whether the rate of water loss correlates with the degree of remineralization and whether that rate can be measured using thermal and near-IR reflectance imaging.

METHODS

Artificial bovine enamel lesions (n=30) were prepared by immersion in a demineralization solution for either 8 and 24 h and they were subsequently placed in an acidic remineralization solution for different periods. The samples were dehydrated using an air spray for 30s and surfaces were imaged using a thermal camera and an InGaAs camera at 1300-1700 nm wavelengths.

RESULTS

The area enclosed by the time-temperature curve, ΔQ, from thermal imaging showed significant differences (P<0.05) between the lesion window and other windows. Near-IR reflectance intensity differences, ΔI, before and after dehydration decreased with longer periods of remineralization. Only near-IR reflectance imaging was capable of detecting significant differences (P<0.05) between the different periods of remineralization.

CONCLUSIONS

This study demonstrated that both thermal and near-IR reflectance imaging were suitable for the detection of remineralization in simulated caries lesions and near-IR wavelengths longer than 1400 nm are well suited for the assessment of remineralization.

Assessment of remineralization in simulated enamel lesions via dehydration with near-IR reflectance imaging

Previous studies have demonstrated that near-IR imaging can be used to nondestructively monitor the severity of enamel lesions. Arrested lesions typically have a highly mineralized surface layer that reduces permeability and limits diffusion into the lesion. The purpose of this study was to investigate whether the rate of water loss correlates with the degree of remineralization using near-IR reflectance imaging. Artificial bovine (n=15) enamel lesions were prepared by immersion in a demineralization solution for 24 hours and they were subsequently placed in an acidic remineralization solution for different periods. The samples were dehydrated using an air spray for 30 seconds and surfaces were imaged using an InGaAs camera at 1300-1700 nm wavelengths. Near-IR reflectance intensity differences before and after dehydration decreased with longer periods of remineralization. This study demonstrated that near-IR reflectance imaging was suitable for the detection of remineralization in simulated caries lesions and near-IR wavelengths longer than 1400 nm are well suited for the assessment of remineralization.

Automated assessment of the remineralization of artificial enamel lesions with polarization-sensitive optical coherence tomography

Accurate measurement of the highly mineralized transparent surface layer that forms on caries lesions is important for diagnosis of the lesion activity because chemical intervention can slow or reverse the caries process via remineralization. Previous in-vitro and in-vivo studies have demonstrated that polarization-sensitive optical coherence tomography (PS-OCT) can nondestructively image the subsurface lesion structure and the highly mineralized transparent surface zone of caries lesions. The purpose of this study was to develop an approach to automatically process 3-dimensional PS-OCT images and to accurately assess the remineralization process in simulated enamel lesions. Artificial enamel lesions were prepared on twenty bovine enamel blocks using two models to produce varying degree of demineralization and remineralization. The thickness of the transparent surface layer and the integrated reflectivity of the subsurface lesion were measured using PS-OCT. The automated transparent surface layer detection algorithm was able to successfully detect the transparent surface layers with high sensitivity ( = 0.92) and high specificity ( = 0.97). The estimated thickness of the transparent surface layer showed a strong correlation with polarized light microscopy (PLM) measurements of all regions (R(2) = 0.90). The integrated reflectivity, ΔR, and the integrated mineral loss, ΔZ, showed a moderate correlation (R(2) = 0.32). This study demonstrates that PS-OCT can automatically measure the changes in artificial enamel lesion structure and severity upon exposure to remineralization solutions.

Effects of the child-perpetrator relationship on mental health outcomes of child abuse: it's (not) all relative

The present study was conducted to better understand the influence of the child-perpetrator relationship on responses to child sexual and physical trauma for a relatively large, ethnically diverse sample of children and youth presenting for clinical evaluation and treatment at child mental health centers across the United States. This referred sample includes 2,133 youth with sexual or physical trauma as their primary treatment focus. Analyses were conducted to ascertain whether outcomes were dependent on the perpetrator's status as a caregiver vs. non-caregiver. Outcome measures included psychiatric symptom and behavior problem rating scales. For sexual trauma, victimization by a non-caregiver was associated with higher posttraumatic stress, internalizing and externalizing behavior problems, depression, and dissociation compared to youth victimized by a caregiver. For physical trauma, victimization by a non-caregiver was also associated with higher posttraumatic symptoms and internalizing behavior problems. The total number of trauma types experienced and age of physical or sexual trauma onset also predicted several outcomes for both groups, although in disparate ways. These findings are consistent with other recent studies demonstrating that perpetration of abuse by caregivers results in fewer symptoms and problems than abuse perpetrated by a non-caregiving relative. Thus, clinicians should not make a priori assumptions that children and adolescents who are traumatized by a parent/caregiver would have more severe symptoms than youth who are traumatized by a non-caregiver. Further exploration of the role of the perpetrator and other trauma characteristics associated with the perpetrator role is needed to advance our understanding of these findings and their implications for clinical practice.

Automated detection of remineralization in simulated enamel lesions with PS-OCT

Previous in vitro and in vivo studies have demonstrated that polarization-sensitive optical coherence tomography (PS-OCT) can be used to nondestructively image the subsurface structure and measure the thickness of the highly mineralized transparent surface zone of caries lesions. There are structural differences between active lesions and arrested lesions, and the surface layer thickness may correlate with activity of the lesion. The purpose of this study was to develop a method that can be used to automatically detect and measure the thickness of the transparent surface layer in PS-OCT images. Automated methods of analysis were used to measure the thickness of the transparent layer and the depth of the bovine enamel lesions produced using simulated caries models that emulate demineralization in the mouth. The transparent layer thickness measured with PS-OCT correlated well with polarization light microscopy (PLM) measurements of all regions (r²=0.9213). This study demonstrates that PS-OCT can automatically detect and measure thickness of the transparent layer formed due to remineralization in simulated caries lesions.

Traumatic childhood experiences in the 21st century: broadening and building on the ACE studies with data from the National Child Traumatic Stress Network

The study objectives were to (a) examine the association between total number of trauma types experienced and child/adolescent behavioral problems and (b) determine whether the number of trauma types experienced predicted youth behavioral problems above and beyond demographic characteristics, using a diverse set of 20 types of trauma. Data came from the National Child Traumatic Stress Network's (NCTSN) Core Data Set (CDS), which includes youth assessed and treated for trauma across the United States. Participants who experienced at least one type of trauma were included in the sample (N = 11,028; age = 1&frac12;-18 years; 52.3% girls). Random effects models were used to account for possible intraclass correlations given treatment services were provided at different NCTSN centers. Logistic regression analyses were used to investigate associations among demographic characteristics, trauma, and emotional and behavioral problems as measured by the Child Behavior Checklist (CBCL). Significant dose-response relations were found between total number of trauma types and behavior problems for all CBCL scales, except Sleep, one of the subscales only administered to 1&frac12;- to 5-year-olds. Thus, each additional trauma type endorsed significantly increased the odds for scoring above the clinical threshold. Results provide further evidence of strong associations between diverse traumatic childhood experiences and a diverse range of behavior problems, and underscore the need for a trauma-informed public health and social welfare approach to prevention, risk reduction, and early intervention for traumatized youth.

Non-destructive clinical assessment of occlusal caries lesions using near-IR imaging methods

OBJECTIVE

Enamel is highly transparent in the near-IR (NIR) at wavelengths near 1,300 nm, and stains are not visible. The purpose of this study was to use NIR transillumination and optical coherence tomography (OCT) to estimate the severity of caries lesions on occlusal surfaces both in vivo and on extracted teeth.

METHODS

Extracted molars with suspected occlusal lesions were examined with OCT and polarization sensitive OCT (PS-OCT), and subsequently sectioned and examined with polarized light microscopy (PLM) and transverse microradiography (TMR). Teeth in test subjects with occlusal caries lesions that were not cavitated or visible on radiographs were examined using NIR transillumination at 1,310 nm using a custom built probe attached to an indium gallium arsenide (InGaAs) camera and a linear OCT scanner. After imaging, cavities were prepared using dye staining to guide caries removal and physical impressions of the cavities were taken.

RESULTS

The lesion severity determined from OCT and PS-OCT scans in vitro correlated with the depth determined using PLM and TMR. Occlusal caries lesions appeared in NIR images with high contrast in vivo. OCT scans showed that most of the lesions penetrated to dentin and spread laterally below the sound enamel.

CONCLUSION

This study demonstrates that both NIR transillumination and OCT are promising new methods for the clinical diagnosis of occlusal caries.

Non-destructive clinical assessment of occlusal caries lesions using near-IR imaging methods

OBJECTIVE

Enamel is highly transparent in the near-IR (NIR) at wavelengths near 1,300 nm, and stains are not visible. The purpose of this study was to use NIR transillumination and optical coherence tomography (OCT) to estimate the severity of caries lesions on occlusal surfaces both in vivo and on extracted teeth.

METHODS

Extracted molars with suspected occlusal lesions were examined with OCT and polarization sensitive OCT (PS-OCT), and subsequently sectioned and examined with polarized light microscopy (PLM) and transverse microradiography (TMR). Teeth in test subjects with occlusal caries lesions that were not cavitated or visible on radiographs were examined using NIR transillumination at 1,310 nm using a custom built probe attached to an indium gallium arsenide (InGaAs) camera and a linear OCT scanner. After imaging, cavities were prepared using dye staining to guide caries removal and physical impressions of the cavities were taken.

RESULTS

The lesion severity determined from OCT and PS-OCT scans in vitro correlated with the depth determined using PLM and TMR. Occlusal caries lesions appeared in NIR images with high contrast in vivo. OCT scans showed that most of the lesions penetrated to dentin and spread laterally below the sound enamel.

CONCLUSION

This study demonstrates that both NIR transillumination and OCT are promising new methods for the clinical diagnosis of occlusal caries.

Taxonometric applications in radiotherapy incident analysis

Recent publications in both the scientific and the popular press have highlighted the risks to which patients expose themselves when entering a healthcare system. Patient safety issues are forcing us to, not only acknowledge that incidents do occur, but also actively develop the means for assessing and managing the risks of such incidents. To do this, we ideally need to know the probability of an incident's occurrence, the consequences or severity for the patient should it occur, and the basic causes of the incident. A structured approach to the description of failure modes is helpful in terms of communication, avoidance of ambiguity, and, ultimately, decision making for resource allocation. In this report, several classification schemes or taxonomies for use in risk assessment and management are discussed. In particular, a recently developed approach that reflects the activity domains through which the patient passes and that can be used as a basis for quantifying incident severity is described. The estimation of incident severity, which is based on the concept of the equivalent uniform dose, is presented in some detail. We conclude with a brief discussion on the use of a defined basic-causes table and how adding such a table to the reports of incidents can facilitate the allocation of resources.

Costs associated with diffuse large B-cell lymphoma patient treatment in a Canadian integrated cancer care center

OBJECTIVE

The objective of this study was to provide a detailed comparative microcosting analysis for two cancer treatment pathways to contribute evidence for resource allocation and operational decision-making in a Canadian cancer care context.

METHODS

We estimated direct medical costs (in 2004 CAN$) of the entire pathway of care for diffuse large B-cell lymphoma (DLBCL) patients in a large Canadian cancer treatment center. Patient samples were defined as those who received R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisone; n = 85) or CHOP (i.e., without rituximab; n = 86) as first-line treatment. All subsequent treatments including palliative care for these patient samples were assessed. Hospitalization costs and unit costs of medical resources were collected from integrated medical organizations. Individual patient resource consumption was assessed via medical chart review.

RESULTS

For first-line treatment, drug cost was the largest contributor to total cost, followed by hospitalization cost. Rituximab was the largest contributor to mean cost differences between R-CHOP and CHOP treatments. For treatments subsequent to first-line treatment, no significant cost differences were found. Hospitalization and transplantation costs were the two largest constituents of total costs subsequent to first-line treatment, followed by drug cost. Patients with advanced stage disease cost significantly more than patients with limited stage disease.

CONCLUSION

This is the first detailed microcosting study that has employed consistent local data to estimate total medical costs for DLBCL patients in Canada. This information is useful for resource allocation planning and operational decisions, because it provides more substantive, relevant evidence as compared to aggregated, literature or extrapolated information.

Probabilistic fault tree analysis of a radiation treatment system

Inappropriate administration of radiation for cancer treatment can result in severe consequences such as premature death or appreciably impaired quality of life. There has been little study of vulnerable treatment process components and their contribution to the risk of radiation treatment (RT). In this article, we describe the application of probabilistic fault tree methods to assess the probability of radiation misadministration to patients at a large cancer treatment center. We conducted a systematic analysis of the RT process that identified four process domains: Assessment, Preparation, Treatment, and Follow-up. For the Preparation domain, we analyzed possible incident scenarios via fault trees. For each task, we also identified existing quality control measures. To populate the fault trees we used subjective probabilities from experts and compared results with incident report data. Both the fault tree and the incident report analysis revealed simulation tasks to be most prone to incidents, and the treatment prescription task to be least prone to incidents. The probability of a Preparation domain incident was estimated to be in the range of 0.1-0.7% based on incident reports, which is comparable to the mean value of 0.4% from the fault tree analysis using probabilities from the expert elicitation exercise. In conclusion, an analysis of part of the RT system using a fault tree populated with subjective probabilities from experts was useful in identifying vulnerable components of the system, and provided quantitative data for risk management.

Using a survey of incident reporting and learning practices to improve organisational learning at a cancer care centre

OBJECTIVES

To motivate improvements in an organisational system by measuring staff perceptions of the organisation's ability to learn from incidents and by analysing their personal experience of incidents.

METHODS

Respondents were questioned on the components of the incident learning system from both a personal and an organisational perspective. The respondents (n = 125) were radiotherapists, nurses, dosimetrists, doctors, and other staff at a major academic cancer centre. Responses were analysed in terms of per cent positive responses and response rate, differences between "frontline" and "support" staff, and the respondent's experience with incidents.

RESULTS

Respondents were more familiar with and more positive about incident identification and reporting--the first two stages of incident learning. Their overall perception of incident learning was most influenced by the investigation and learning components of the system. Respondents in frontline positions were more positive than those in support positions about responding to, identifying and reporting incidents. Respondents reported having experienced a mean of three incidents per year, of which two were reported and two out of three of the reported incidents were investigated, and a median of two incidents being experienced and reported, but none investigated. Most incidents experienced were not captured by the organisation's existing incident reporting system.

CONCLUSION

The survey tool was effective in measuring the ability of the organisation to learn from incidents. Implications of the survey results for improving organisational learning are discussed.

The Equivalent Uniform Dose as a severity metric for radiation treatment incidents

In allocating resources within a risk management program, ideally we would like to know both the probabilities and consequences of potential incidents. We simulate, on a treatment planning computer, several commonly reported incidents in radiation treatment and explore their consequences for the EUDs of targets and organs at risk.

Stability of cellular proteins under supraphysiological temperatures

We present quantitative analyses of the kinetics of cellular components confronted with the destabilizing effect of irreversible thermal denaturation. We examine the dependence of the thermal denaturation on the heating rate, relative stability, population and lifetime of the states involved in transition and crowding effects. We propose a mechanism for self-stabilization of proteins during unfolding in tightly packed fibers and membranes. Speaking in terms of vulnerability to thermal denaturation, our results suggest that the thermal alteration of the plasma membrane is likely to be the most significant cause of the tissue necrosis.

Magnetic resonance imaging of muscle electroporation injury

Low frequency electrical currents traversing the body during electrical shock can produce tissue damage by effects of electrical forces on cellular organelles and proteins as well as by Joule heating beyond thermotolerance. Treatment for these different injuries are quite distinct. Therefore, it is important to accurately diagnose the form of injury. Here we discuss the use of MRI for this purpose.