Single-cell multiomic analysis of thymocyte development reveals drivers of CD4+ T cell and CD8+ T cell lineage commitment

The development of CD4+ T cells and CD8+ T cells in the thymus is critical to adaptive immunity and is widely studied as a model of lineage commitment. Recognition of self-peptide major histocompatibility complex (MHC) class I or II by the T cell antigen receptor (TCR) determines the CD8+ or CD4+ T cell lineage choice, respectively, but how distinct TCR signals drive transcriptional programs of lineage commitment remains largely unknown. Here we applied CITE-seq to measure RNA and surface proteins in thymocytes from wild-type and T cell lineage-restricted mice to generate a comprehensive timeline of cell states for each T cell lineage. These analyses identified a sequential process whereby all thymocytes initiate CD4+ T cell lineage differentiation during a first wave of TCR signaling, followed by a second TCR signaling wave that coincides with CD8+ T cell lineage specification. CITE-seq and pharmaceutical inhibition experiments implicated a TCR-calcineurin-NFAT-GATA3 axis in driving the CD4+ T cell fate. Our data provide a resource for understanding cell fate decisions and implicate a sequential selection process in guiding lineage choice.

Presentation of Human Neural Stem Cell Antigens Drives Regulatory T Cell Induction

Transplantation of human neural stem cells (hNSCs) is a promising regenerative therapy to promote remyelination in patients with multiple sclerosis (MS). Transplantation of hNSCs has been shown to increase the number of CD4+CD25+Foxp3+ T regulatory cells (Tregs) in the spinal cords of murine models of MS, which is correlated with a strong localized remyelination response. However, the mechanisms by which hNSC transplantation leads to an increase in Tregs in the CNS remains unclear. We report that hNSCs drive the conversion of T conventional (Tconv) cells into Tregs in vitro. Conversion of Tconv cells is Ag driven and fails to occur in the absence of TCR stimulation by cognate antigenic self-peptides. Furthermore, CNS Ags are sufficient to drive this conversion in the absence of hNSCs in vitro and in vivo. Importantly, only Ags presented in the thymus during T cell selection drive this Treg response. In this study, we investigate the mechanisms by which hNSC Ags drive the conversion of Tconv cells into Tregs and may provide key insight needed for the development of MS therapies.

Studying T Cell Development in Neonatal and Adult Thymic Slices

T cell development occurs in the thymus and is coordinated temporally and spatially within the highly complex thymic microenvironment. Therefore, T cell selection and maturation events cannot be fully recapitulated using traditional two-dimensional tissue culture in vitro. The thymic slice system provides a highly versatile system for studying T cell development ex vivo while preserving three-dimensional thymic architecture. Using the thymic slice system, T cell selection and maturation events can be visualized by live imaging and quantified by flow cytometry. Here we describe the process for generating slices from neonatal and adult mice.

Caregiver-reported executive functioning and associated adaptive and challenging behaviour in children with histories of developmental delay

BACKGROUND

Deficits in executive functioning (EF) have been measured in individuals with developmental disabilities, such as autism spectrum disorder and attention-deficit/hyperactivity disorder, through the use of behaviour rating scales and performance-based assessment. Associations between EF and variables such as challenging and adaptive behaviour have been observed; however, limited research exists on EF profiles in children with heterogeneous developmental delay or with intellectual disability (ID) or the impact of EF on adaptive and challenging behaviour with this population.

METHODS

The present study sought to examine the EF profile of 93 children (75 male and 18 female) previously identified with developmental delay in early childhood. EF was assessed using the Behaviour Rating Inventory of Executive Function, Second Edition (BRIEF-2). Children were categorised into an ID group (n = 14) or no ID group (n = 79) based on scores from cognitive and adaptive behaviour assessments. EF profiles were investigated and compared by group. In addition, the impact of EF on both adaptive behaviour and challenging behaviour was measured using hierarchical linear regressions.

RESULTS

Statistically significant differences in caregiver-reported EF were not observed between groups; however, both the ID and the no ID group scores were elevated as reported by their caregivers. For the overall sample, caregiver-EF accounted for significant variance in both adaptive (22%) and challenging (68%) behaviour after accounting for child age and sex.

CONCLUSIONS

Results indicated deficits in EF for children with and without ID. The significance of EF was accounted for in both adaptive and challenging behaviour for all children in the sample. Future research could elucidate the role of adaptive and challenging behaviour in understanding EF variability among children with histories of developmental delay.

T cell self-reactivity during thymic development dictates the timing of positive selection

Functional tuning of T cells based on their degree of self-reactivity is established during positive selection in the thymus, although how positive selection differs for thymocytes with relatively low versus high self-reactivity is unclear. In addition, preselection thymocytes are highly sensitive to low-affinity ligands, but the mechanism underlying their enhanced T cell receptor (TCR) sensitivity is not fully understood. Here we show that murine thymocytes with low self-reactivity experience briefer TCR signals and complete positive selection more slowly than those with high self-reactivity. Additionally, we provide evidence that cells with low self-reactivity retain a preselection gene expression signature as they mature, including genes previously implicated in modulating TCR sensitivity and a novel group of ion channel genes. Our results imply that thymocytes with low self-reactivity downregulate TCR sensitivity more slowly during positive selection, and associate membrane ion channel expression with thymocyte self-reactivity and progress through positive selection.

Regulatory T cells promote remyelination in the murine experimental autoimmune encephalomyelitis model of multiple sclerosis following human neural stem cell transplant

Multiple sclerosis (MS) is a chronic, inflammatory autoimmune disease that affects the central nervous system (CNS) for which there is no cure. In MS, encephalitogenic T cells infiltrate the CNS causing demyelination and neuroinflammation; however, little is known about the role of regulatory T cells (Tregs) in CNS tissue repair. Transplantation of neural stem and progenitor cells (NSCs and NPCs) is a promising therapeutic strategy to promote repair through cell replacement, although recent findings suggest transplanted NSCs also instruct endogenous repair mechanisms. We have recently described that dampened neuroinflammation and increased remyelination is correlated with emergence of Tregs following human NPC transplantation in a murine viral model of immune-mediated demyelination. In the current study we utilized the prototypic murine autoimmune model of demyelination experimental autoimmune encephalomyelitis (EAE) to test the efficacy of hNSC transplantation. Eight-week-old, male EAE mice receiving an intraspinal transplant of hNSCs during the chronic phase of disease displayed remyelination, dampened neuroinflammation, and an increase in CNS CD4⁺CD25⁺FoxP3⁺ regulatory T cells (Tregs). Importantly, ablation of Tregs abrogated histopathological improvement. Tregs are essential for maintenance of T cell homeostasis and prevention of autoimmunity, and an emerging role for Tregs in maintenance of tissue homeostasis through interactions with stem and progenitor cells has recently been suggested. The data presented here provide direct evidence for collaboration between CNS Tregs and hNSCs promoting remyelination.

Human neural stem cells induce central nervous system specific regulatory T cells from the exTreg pool and promote repair in models of multiple sclerosis

Multiple Sclerosis (MS) is a chronic inflammatory autoimmune disease affecting the central nervous system (CNS) and for which there is no cure. Current treatments focus on suppression of the immune system but fail to repair the resulting damage to the CNS. Neural stem cell (NSC) transplantation is a promising therapeutic strategy for treating neurodegenerative diseases through cell replacement and repair however it is unclear how these cells would mediate repair in MS. We report that human NSCs promote CNS specific T regulatory cells (Tregs) which activate endogenous repair pathways and promote remyelination in a murine model of MS. We observed remyelination, decreased inflammation and an increase in (CNS)-infiltrating CD4+CD25+FoxP3+ Tregs in EAE mice receiving an intra-spinal transplant of hNSCs. Recovery was not a result of cell replacement, as hNSCs underwent xenograft rejection, and was Treg dependent, as ablation of Tregs abrogated histopathological improvement. Treg expansion is antigen driven as hNSCs expanded CD25+FoxP3+ Tregs in-vitro when cultured with neural antigen restricted RAG2−/−2D2+ (R2D2) splenocytes but not RAG2−/−OT-II+ splenocytes. When co-cultured with B6 splenocytes, hNSCs drove the expansion of unique TCRs when compared to controls. Additionally, hNSC-Tregs also appear to derive from the exTreg pool suggesting both antigen specific expansion and antigen dependent maintenance of FOXP3 in CNS-specific Tregs. hNSC Tregs also have a unique expression profile and express transglutimase-2 which is implicated in oligodendrocyte dependent repair in the CNS.

Interleukin 30 to Interleukin 40

Cytokines are important molecules that regulate the ontogeny and function of the immune system. They are small secreted proteins usually produced upon activation of cells of the immune system, including lymphocytes and myeloid cells. Many cytokines have been described, and several have been recognized as pivotal players in immune responses and in human disease. In fact, several anticytokine antibodies have proven effective therapeutics, especially in various autoimmune diseases. In the last 15 years, new cytokines have been described, and many remain poorly understood. Among the most recent cytokines discovered are interleukins-30 (IL-30) to IL-40. Several of these are members of other cytokine superfamilies, including several IL-1 superfamily members (IL-33, IL-36, IL-37, and IL-38) as well as several new members of the IL-12 family (IL-30, IL-35, and IL-39). The rest (IL-31, IL-32, IL-34, and IL-40) are encoded by genes that do not belong to any cytokine superfamily. Our aim of this review was to present a concise version of the information available on these novel cytokines to facilitate their understanding by members of the immunological community.

Stem Cell-Derived Exosomes as Nanotherapeutics for Autoimmune and Neurodegenerative Disorders

To dissect therapeutic mechanisms of transplanted stem cells and develop exosome-based nanotherapeutics in treating autoimmune and neurodegenerative diseases, we assessed the effect of exosomes secreted from human mesenchymal stem cells (MSCs) in treating multiple sclerosis using an experimental autoimmune encephalomyelitis (EAE) mouse model. We found that intravenous administration of exosomes produced by MSCs stimulated by IFNγ (IFNγ-Exo) (i) reduced the mean clinical score of EAE mice compared to PBS control, (ii) reduced demyelination, (iii) decreased neuroinflammation, and (iv) upregulated the number of CD4+CD25+FOXP3+ regulatory T cells (Tregs) within the spinal cords of EAE mice. Co-culture of IFNγ-Exo with activated peripheral blood mononuclear cells (PBMCs) cells in vitro reduced PBMC proliferation and levels of pro-inflammatory Th1 and Th17 cytokines including IL-6, IL-12p70, IL-17AF, and IL-22 yet increased levels of immunosuppressive cytokine indoleamine 2,3-dioxygenase. IFNγ-Exo could also induce Tregs in vitro in a murine splenocyte culture, likely mediated by a third-party accessory cell type. Further, IFNγ-Exo characterization by deep RNA sequencing suggested that IFNγ-Exo contains anti-inflammatory RNAs, where their inactivation partially hindered the exosomes potential to induce Tregs. Furthermore, we found that IFNγ-Exo harbors multiple anti-inflammatory and neuroprotective proteins. These results not only shed light on stem cell therapeutic mechanisms but also provide evidence that MSC-derived exosomes can potentially serve as cell-free therapies in creating a tolerogenic immune response to treat autoimmune and central nervous system disorders.

Single cell RNA sequencing reveals distinct gene expression signatures of myeloidderived suppressor cells in breast cancer

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells with potent immune suppressive activity. MDSCs regulate anti-tumor immunity by suppressing T cell proliferation. MDSCs can be further classified into granulocytic MDSCs (G-MDSCs) and monocytic MDSC (M-MDSCs). However, there is a lack of MDSC-specific markers since MDSCs, normal neutrophil granulocytes, and monocytes are defined by the same flow cytometry markers (CD11b+Gr1+). We used a breast cancer mouse model (MMTV-PyMT) to define cellular and molecular properties of MDSCs in single cell resolution. To test the capacity of MDSCs to inhibit immune responses, CD11b+Gr1+ cells from PyMT and wild type (WT) mice were sorted by fluorescence-activated cell sorting (FACS) from bone marrow, lung, and spleen, and then subjected to a T cell activation assay in co-culture with T cells. We found that predominantly spleen-derived CD11b+Gr1+ cells from PyMT significantly suppressed CD4 and CD8 T cell proliferation, while CD11b+Gr1+cells from bone marrow and lung showed no effect on T cell proliferation. Thus, we focused on spleen-derived CD11b+Gr1+ cells and utilized single cell RNA sequencing (scRNAseq) to compare breast cancer derived MDSCs to the respective cell populations harvested from normal, and non-tumor bearing hosts. Our computational analysis of 14,646 single cell transcriptomes revealed a separate G-MDSCs cluster from normal neutrophils and a M-MDSCs cluster from normal monocytes and a distinct gene expression signature for the entire MDSCs population. Our studies provide crucial insights into the biology of MDSCs, which may ultimately form the basis for novel marker and therapeutic avenues to improve cancer immunotherapy.

Human neural stem cells induce central nervous system specific regulatory T cells from the ex Treg pool and promote repair in models of multiple sclerosis

Multiple Sclerosis (MS) is a chronic inflammatory autoimmune disease affecting the central nervous system (CNS) and for which there is no cure. Current treatments focus on suppression of the immune system but fail to repair the resulting damage to the CNS. Neural stem cell (NSC) transplantation is a promising therapeutic strategy for treating neurodegenerative diseases through cell replacement and repair however it is unclear how these cells would mediate repair in MS. We report that human NSCs promote CNS specific T regulatory cells (Tregs) which activate endogenous repair pathways and promote remyelination in a murine model of MS. We observed remyelination, decreased inflammation and an increase in (CNS)-infiltrating CD4+CD25+FoxP3+ Tregs in EAE mice receiving an intra-spinal transplant of NSCs. Recovery was not a result of cell replacement, as NSCs underwent xenograft rejection, and was Treg dependent, as ablation of Tregs abrogated histopathological improvement. RAG2−/−2D2 (R2D2) mice, which bear a TCR repertoire restricted to myelin oligodendrocyte glycoprotein (MOG) and neurofilament, lack CD25+FoxP3+ Tregs under homeostatic conditions; however, upon exposure to MOG, R2D2 mice developed CD25+FoxP3+ Tregs in cervical lymph nodes and the spinal cord. hNSCs also promoted Tregs in vitro in co-cultures with wild type B6 and R2D2 splenocytes, but not with RAG2−/− OT-II+ splenocytes. Additionally, hNSC-Tregs also appear to derive from the exTreg pool suggesting both antigen specific expansion and antigen dependent maintenance of FOXP3 in CNS-specific Tregs. hNSC Tregs also have a unique expression profile and express transglutimase-2 which is implicated in oligodendrocyte dependent repair in the CNS.

CD11a expression distinguishes infiltrating myeloid cells from plaque-associated microglia in Alzheimer's disease

Alzheimer's disease (AD) is the leading cause of age-related neurodegeneration and is characterized neuropathologically by the accumulation of insoluble beta-amyloid (Aβ) peptides. In AD brains, plaque-associated myeloid (PAM) cells cluster around Aβ plaques but fail to effectively clear Aβ by phagocytosis. PAM cells were originally thought to be brain-resident microglia. However, several studies have also suggested that Aβ-induced inflammation causes peripheral monocytes to enter the otherwise immune-privileged brain. The relationship between AD progression and inflammation in the brain remains ambiguous because microglia and monocyte-derived macrophages are extremely difficult to distinguish from one another in an inflamed brain. Whether PAM cells are microglia, peripheral macrophages, or a mixture of both remains unclear. CD11a is a component of the β2 integrin LFA1. We have determined that CD11a is highly expressed on peripheral immune cells, including macrophages, but is not expressed by mouse microglia. These expression patterns remain consistent in LPS-treated inflamed mice, as well as in two mouse models of AD. Thus, CD11a can be used as a marker to distinguish murine microglia from infiltrating peripheral immune cells. Using CD11a, we show that PAM cells in AD transgenic brains are comprised entirely of microglia. We also demonstrate a novel fluorescence-assisted quantification technique (FAQT), which reveals a significant increase in T lymphocytes, especially in the brains of female AD mice. Our findings support the notion that microglia are the lead myeloid players in AD and that rejuvenating their phagocytic potential may be an important therapeutic strategy.

Promoting remyelination through cell transplantation therapies in a model of viral-induced neurodegenerative disease

Multiple sclerosis (MS) is a central nervous system (CNS) disease characterized by chronic neuroinflammation, demyelination, and axonal damage. Infiltration of activated lymphocytes and myeloid cells are thought to be primarily responsible for white matter damage and axonopathy. Several United States Food and Drug Administration-approved therapies exist that impede activated lymphocytes from entering the CNS thereby limiting new lesion formation in patients with relapse-remitting forms of MS. However, a significant challenge within the field of MS research is to develop effective and sustained therapies that allow for axonal protection and remyelination. In recent years, there has been increasing evidence that some kinds of stem cells and their derivatives seem to be able to mute neuroinflammation as well as promote remyelination and axonal integrity. Intracranial infection of mice with the neurotropic JHM strain of mouse hepatitis virus (JHMV) results in immune-mediated demyelination and axonopathy, making this an excellent model to interrogate the therapeutic potential of stem cell derivatives in evoking remyelination. This review provides a succinct overview of our recent findings using intraspinal injection of mouse CNS neural progenitor cells and human neural precursors into JHMV-infected mice. JHMV-infected mice receiving these cells display extensive remyelination associated with axonal sparing. In addition, we discuss possible mechanisms associated with sustained clinical recovery. Developmental Dynamics 248:43-52, 2019. © 2018 Wiley Periodicals, Inc.

Optimism and positive and negative feelings in parents of young children with developmental delay

BACKGROUND

Parents' positive and negative feelings about their young children influence both parenting behaviour and child problem behaviour. Research has not previously examined factors that contribute to positive and negative feelings in parents of young children with developmental delay (DD).

METHOD

The present study sought to examine whether optimism, a known protective factor for parents of children with DD, was predictive of positive and negative feelings for these parents. Data were collected from 119 parents of preschool-aged children with developmental delay. Two separate hierarchical linear regression analyses were conducted to determine if optimism significantly predicted positive feelings and negative feelings and whether optimism moderated relations between parenting stress and parent feelings.

RESULTS

Increased optimism was found to predict increased positive feelings and decreased negative feelings after controlling for child problem behaviour and parenting stress. In addition, optimism was found to moderate the relation between parenting stress and positive feelings.

CONCLUSION

Results suggest that optimism may impact how parents perceive their children with DD. Future research should examine how positive and negative feelings impact positive parenting behaviour and the trajectory of problem behaviour specifically for children with DD.

Adapting Webster-Stratton's incredible years parent training for children with developmental delay: findings from a treatment group only study

BACKGROUND

Children with intellectual or developmental disabilities (ID/DD) are more likely than typically developing children to experience behaviour problems. Parent training, such as the Incredible Years Parent Training (IYPT) series, has been a widely used intervention to support families with children with or at-risk for behaviour problems; yet to date, this programme has not been used with parents with young children with developmental delay or disabilities.

METHOD

This preliminary treatment group only study assessed the feasibility of implementing a modified parent training programme (IYPT-DD) with 25 families with 2-5-year-old children with developmental delay. Intervention consisted of 12 weekly (2.5 h) sessions with topics covering developmentally appropriate play, praise, rewards, limit setting and handling challenging behaviour.

RESULTS

Results suggest preliminary evidence of efficacy in reducing negative parent and child behaviour and increasing parental perceptions of child positive impact.

CONCLUSIONS

This study provides evidence for the feasibility of the DD modifications applied to the IYPT. Although this approach is promising, additional evidence is needed to address the efficacy of IYPT-DD in children with developmental delay.

The transition to school: adaptation in young children with and without intellectual disability

BACKGROUND

Previous research has highlighted the importance of the transition to school for young children and their families. A child's successful adaptation to school is likely influenced by a number of factors, including academic, social, emotional, behavioural and cognitive competencies. Children with intellectual disability (ID) may be at heightened risk for early school difficulties, in part due to their deficits in cognitive and adaptive behaviours.

METHODS

Factors associated with the adaptive transition to school in young children with (n = 24) and without (n = 43) ID were examined. Adaptive transitions were defined as having few teacher-reported problem behaviours and positive student-teacher relationships. Child self-regulatory skills and both parent- and teacher-reported social skills were evaluated to determine if they predicted positive adaptation in school for 5- to 6-year-old children. Data were gathered from child assessments, parent reports on standardized measures, direct observations of delay of gratification tasks and teacher reports on standardized measures.

RESULTS

Children with ID had significantly more teacher-reported problem behaviour, poorer overall student-teacher relationships, fewer parent- and teacher-reported social skills and fewer self-regulation skills than typically developing children. Self-regulation at child age 36 months (latency to touch a desired toy) was significantly related to adaptation to school, as were parent and teacher reports of social skills. Social skills significantly predicted adaptation to school, even after accounting for the effects of child IQ and adaptive behaviour.

CONCLUSIONS

Children with ID had less positive early school experiences, as indicated by multiple indices of adaptation to school. Fostering early social skills may be an important target for increasing the positive adaptation to school for young children, especially those with ID.

Syndrome specificity and behavioural disorders in young adults with intellectual disability: cultural differences in family impact

BACKGROUND

This study examined whether behaviour problems and adaptive behaviour of low functioning young adults, and well-being of their families, varied by diagnostic syndrome [intellectual disability (ID) only, cerebral palsy, Down syndrome, autism], as well as by cultural group.

METHODS

Behaviour disorders in young adults with moderate to severe ID were assessed from information provided by 282 caregivers during in-home interviews. The sample consisted of 150 Anglo participants, and 132 Latino, primarily Spanish-speaking, participants drawn from Southern California.

RESULTS

Behaviour disorders and maternal well-being showed the same pattern across disability syndromes. Autism was associated with the highest scores in multiple behaviour problem areas as well as maternal reports of lower well-being. Down syndrome was associated with the lowest behaviour problem scores and the highest maternal well-being. When behaviour problems were controlled for, diagnostic groups accounted for no additional variance in maternal stress or depression. The pattern of behaviour problems and well-being did not differ by sample (Anglo vs. Latino), although level on well-being measures did. Latina mothers reported significantly higher depression symptoms and lower morale, but also higher positive impact from their child than did Anglo mothers.

CONCLUSIONS

Caregivers of young adults with autism report more maladaptive behaviour problems and lower personal well-being, or stress, relative to other diagnostic groups, regardless of cultural group. However, cultural differences exist in caregiver reports of depression, morale, and positive perceptions. Implications for service provision aimed at families of children with challenging behaviour problems are discussed in the context of culture.

Syndrome specificity and behavioural disorders in young adults with intellectual disability: cultural differences in family impact

BACKGROUND

This study examined whether behaviour problems and adaptive behaviour of low functioning young adults, and well-being of their families, varied by diagnostic syndrome [intellectual disability (ID) only, cerebral palsy, Down syndrome, autism], as well as by cultural group.

METHODS

Behaviour disorders in young adults with moderate to severe ID were assessed from information provided by 282 caregivers during in-home interviews. The sample consisted of 150 Anglo participants, and 132 Latino, primarily Spanish-speaking, participants drawn from Southern California.

RESULTS

Behaviour disorders and maternal well-being showed the same pattern across disability syndromes. Autism was associated with the highest scores in multiple behaviour problem areas as well as maternal reports of lower well-being. Down syndrome was associated with the lowest behaviour problem scores and the highest maternal well-being. When behaviour problems were controlled for, diagnostic groups accounted for no additional variance in maternal stress or depression. The pattern of behaviour problems and well-being did not differ by sample (Anglo vs. Latino), although level on well-being measures did. Latina mothers reported significantly higher depression symptoms and lower morale, but also higher positive impact from their child than did Anglo mothers.

CONCLUSIONS

Caregivers of young adults with autism report more maladaptive behaviour problems and lower personal well-being, or stress, relative to other diagnostic groups, regardless of cultural group. However, cultural differences exist in caregiver reports of depression, morale, and positive perceptions. Implications for service provision aimed at families of children with challenging behaviour problems are discussed in the context of culture.

Pre-school children with and without developmental delay: behaviour problems and parenting stress over time

BACKGROUND

Children with intellectual disability are at heightened risk for behaviour problems and diagnosed mental disorder.

METHODS

The present authors studied the early manifestation and continuity of problem behaviours in 205 pre-school children with and without developmental delays.

RESULTS

Behaviour problems were quite stable over the year from age 36-48 months. Children with developmental delays were rated higher on behaviour problems than their non-delayed peers, and were three times as likely to score in the clinical range. Mothers and fathers showed high agreement in their rating of child problems, especially in the delayed group. Parenting stress was also higher in the delayed group, but was related to the extent of behaviour problems rather than to the child's developmental delay.

CONCLUSIONS

Over time, a transactional model fit the relationship between parenting stress and behaviour problems: high parenting stress contributed to a worsening in child behaviour problems over time, and high child behaviour problems contributed to a worsening in parenting stress. Findings for mothers and fathers were quite similar.

Behaviour/mental health problems in young adults with intellectual disability: the impact on families

BACKGROUND

The present authors studied the impact of dual diagnosis [i.e. intellectual disability (ID) and mental disorder] in young adults on their mothers' perceived levels of stress and decisions about placement.

METHODS

The mothers of 103 young adults with severe ID were interviewed using a 2-3-h in-depth protocol of measures designed to assess their child's adaptive functioning, maladaptive behaviour, mental health problems and negative impact on the family, as well as their own thoughts on out-of-home placement. The Scales of Independent Behavior--Revised Problem Behavior Scale assessed problem behaviours and the Reiss Screen assessed mental disorder.

RESULTS

These measures were highly correlated (r = 0.64), but tapped some different domains of maladaptive behaviour and proved to be most predictive when employed together. Behaviour and/or mental health (B/MH) problems significantly predicted the mothers' perceived negative impact of the young adult on the family, even after controlling for other young adult characteristics. These problems also predicted the family's steps toward seeking out-of-home placement, as did better young adult health and the mother's higher educational attainment; stress did not predict additional variance in placement once these variables were accounted for.

CONCLUSIONS

The discussion focuses on the implications for service provision to families of young adults with B/MH problems.

Negative predictive value of a population-based preschool vision screening program

BACKGROUND

The Enhanced Vision Screening Program is a population-based vision screening program that has, at present, examined 59,782 children. Its main goal is to detect amblyopia, strabismus, and high refractive errors. An average of 11,910 4 1/2- to 5 1/2-year-old children are screened yearly. The current study determines the negative predictive value of the screening program: For a subject having passed the vision screening test, what is the probability of not having amblyopia, strabismus, or high refractive errors?

METHODS

Of the 11,734 subjects who passed the vision screening, 200 were randomly chosen to undergo a strictly defined gold standard examination by an orthoptist and an ophthalmologist.

RESULTS

Of the 200 randomly chosen subjects, 157 underwent the gold standard evaluation. The negative predictive value of the Enhanced Vision Screening Program was 97.6% for any potentially vision-threatening ocular condition. It was 98.7% if we considered only the visually significant ocular problems that the test was designed to detect.

CONCLUSION

Because the negative predictive value of the Enhanced Vision Screening Program is not 100%, some children with amblyopia, strabismus, or refractive errors are missed. Occasionally, a rare, potentially vision-threatening condition may go undetected. Parents should be made aware of this when they receive the results of the vision screening.

Epidemiologic features of diabetes mellitus among Indians in northwestern Ontario and northeastern Manitoba

This descriptive epidemiologic study of diabetes mellitus among Indians in northwestern Ontario and northeastern Manitoba provided estimates of the prevalence of diagnosed cases: 28/1000 overall, 46/1000 for those aged 15 to 64 years and 96/1000 for those aged 65 years and over. Diabetes was more prevalent among women than men but was rare in children. More than half of the existing cases had been diagnosed within the last 5 years studied (1978-82). Comparisons with Canadians nationally and other North American Indian groups were made with caution owing to the different methods of case ascertainment. Duration of disease and pre-existing hypertension were found to be statistically significant risk factors for the development of complications of diabetes in this population.