The vertebrate lens provides an excellent model with which to study the mechanisms required for epithelial invagination. In the mouse, the lens forms from the head surface ectoderm. A domain of ectoderm first thickens to form the lens placode and then invaginates to form the lens pit. The epithelium of the lens placode remains in close apposition to the epithelium of the presumptive retina as these structures undergo a coordinated invagination. Here, we show that F-actin-rich basal filopodia that link adjacent presumptive lens and retinal epithelia function as physical tethers that coordinate invagination. The filopodia, most of which originate in the presumptive lens, form at E9.5 when presumptive lens and retinal epithelia first come into close contact, and have retracted by E11.5 when invagination is complete. At E10.5 -the lens pit stage -there is approximately one filopodium per epithelial cell. Formation of filopodia is dependent on the Rho family GTPase Cdc42 and the Cdc42 effector IRSp53 (Baiap2). Loss of filopodia results in reduced lens pit invagination. Pharmacological manipulation of the actin-myosin contraction pathway showed that the filopodia can respond rapidly in length to change inter-epithelial distance. These data suggest that the lens-retina interepithelial filopodia are a fine-tuning mechanism to assist in lens pit invagination by transmitting the forces between presumptive lens and retina. Although invagination of the archenteron in sea urchins and dorsal closure in Drosophila are known to be partly dependent on filopodia, this mechanism of morphogenesis has not previously been identified in vertebrates.

The lacrimal gland provides an excellent model with which to study the epithelial-mesenchymal interactions that are crucial to the process of branching morphogenesis. In the current study, we show that bone morphogenetic protein 7 (Bmp7) is expressed with a complex pattern in the developing gland and has an important role in regulating branching. In loss-of-function analyses, we find that Bmp7-null mice have distinctive reductions in lacrimal gland branch number, and that inhibition of Bmp activity in gland explant cultures has a very similar consequence. Consistent with this,exposure of whole-gland explants to recombinant Bmp7 results in increased branch number. In determining which cells of the gland respond directly to Bmp7, we have tested isolated mesenchyme and epithelium. We find that, as expected, Bmp4 can suppress bud extension in isolated epithelium stimulated by Fgf10, but interestingly, Bmp7 has no discernible effect. Bmp7 does, however,stimulate a distinct response in mesenchymal cells. This manifests as a promotion of cell division and formation of aggregates, and upregulation of cadherin adhesion molecules, the junctional protein connexin 43 and ofα-smooth muscle actin. These data suggest that in this branching system,mesenchyme is the primary target of Bmp7 and that formation of mesenchymal condensations characteristic of signaling centers may be enhanced by Bmp7. Based on the activity of Bmp7 in promoting branching, we also propose a model suggesting that a discrete region of Bmp7-expressing head mesenchyme may be crucial in determining the location of the exorbital lobe of the gland.

HIV-infected AYAs are vulnerable to VF, especially during the transition period. Identification of HIV-infected adolescents at high risk for VF might help to improve treatment success in this group.

Background: Obsessive-compulsive disorder (OCD) is a severe condition with varied symptom presentations. Currently, the cognitive-behavioral treatment with the most empirical support is exposure and ritual prevention (EX/RP); however, clinical impression and some empirical data suggest that certain OCD symptoms are more responsive to treatment than others. Methods: Prior work identifying symptom dimensions within OCD is discussed, including epidemiological findings, factor analytic studies, and biological findings. Symptom dimensions most reliably identified include contamination/cleaning, doubt about harm/checking, symmetry/ordering, and unacceptable thoughts/mental rituals. The phenomenology of each of these subtypes is described and research literature is summarized, emphasizing the differential effects of EX/RP and its variants on each of these primary symptom dimensions. Results: To date it appears that EX/RP is an effective treatment for the various OCD dimensions, although not all dimensions have been adequately studied (i.e. symmetry and ordering). Conclusions: Modifications to treatment may be warranted for some types of symptoms. Clinical implications and directions for future research are discussed.

This article reviews the current research literature concerning Black people in Western societies to better understand how they regulate their emotions when coping with racism, which coping strategies they use, and which strategies are functional for well-being. A systematic review of the literature was conducted, and 26 studies were identified on the basis of a comprehensive search of multiple databases and reference sections of relevant articles. Studies were quantitative and qualitative, and all articles located were from the United States or Canada. Findings demonstrate that Black people tend to cope with racism through social support (friends, family, support groups), religion (prayer, church, spirituality), avoidance (attempting to avoid stressors), and problem-focused coping (confronting the situation directly). Findings suggest gender differences in coping strategies. We also explore the relationship between coping with physical versus emotional pain and contrast functional versus dysfunctional coping approaches, underscoring the importance of encouraging personal empowerment to promote psychological well-being. Findings may help inform mental-health interventions. Limitations include the high number of American-based samples and exclusion of other Black ethnic and national groups, which is an important area for further exploration.

Purpose of Review While research has identified racial trauma in other contexts, it is often overlooked amongst Canadian society. Racial trauma occurs as a result of an event of racism or cumulative events over time whereby an individual experiences stress and consequent mental health sequelae. Given that the BIPOC (Black, Indigenous, and/or Person of Colour) population in Canada is increasing, it is imperative to identify racial discrimination and the subsequent stress and trauma associated with being racialized in Canada, which subjects BIPOC Canadians to various forms of racism, including microaggressions. Recent Findings This paper reviews the published literature on racism and racial discrimination that identifies or infers racial trauma as the source of the mental health implications for various groups (e.g., Indigenous people, Black Canadians, Asian Canadians, immigrants, and refugees). In addition, intersectionality of racialized persons is prominent to their psychological well-being as their psychosocial and socioeconomic position are complex. Therefore, this paper both provides insight into the Canadian experience as a person of colour and signifies the need for further research on racial trauma in a Canadian context. Summary Despite Canada's emphasis on multiculturalism, racialized individuals are at risk for racial trauma due to prejudice and discrimination. The politicization of multiculturalism has permitted Canada to deny claims of racism, yet the historical basis of established institutions results in irrefutable systemic and systematic barriers for Canadian people of colour. KeywordsDiscrimination • Racism • Racial trauma • Canadians of colour • Microaggressions • Intersectionality This article is part of the Topical collection on Racism, Equity and Disparities in Trauma

We investigated the mechanism of tissue induction and specification using the lacrimal gland as a model system. This structure begins its morphogenesis as a bud-like outgrowth of the conjunctival epithelium and ultimately forms a branched structure with secretory function. Using a reporter transgene as a specific marker for gland epithelium, we show that the transcription factor Pax6 is required for normal development of the gland and is probably an important competence factor. In investigating the cell-cell signaling required, we show that fibroblast growth factor (FGF) 10 is sufficient to stimulate ectopic lacrimal bud formation in ocular explants. Expression of FGF10 in the mesenchyme adjacent to the presumptive lacrimal bud and absence of lacrimal gland development in FGF10-null mice strongly suggest that it is an endogenous inducer. This was supported by the observation that inhibition of signaling by a receptor for FGF10 (receptor 2 IIIb) suppressed development of the endogenous lacrimal bud. In explants of mesenchyme-free gland epithelium, FGF10 stimulated growth but not branching morphogenesis. This suggested that its role in induction is to stimulate proliferation and, in turn, that FGF10 combines with other factors to provide the instructive signals required for lacrimal gland development.

Aims: We established a real-time PCR assay for the detection and strain identification of Candida species and demonstrated the ability to differentiate between Candida albicans the most common species, and also Candida parapsilosis, Candida glabrata, Candida tropicalis and Candida dubliniensis by LightCycler PCR and melting curve analysis. Methods and Results: The DNA isolation from cultures and serum was established using the QIAmp Tissue Kit. The sensitivity of the assay was >/= 2 genome equivalents/assay. It was possible to differentiate all investigated Candida species by melting curve analysis, and no cross-reaction to human DNA or Aspergillus species could be observed. Conclusions: The established real-time PCR assay is a useful tool for the rapid identification of Candida species and a base technology for more complex PCR assays. Significance and Impact of the Study: We carried out initial steps in validation of a PCR assay for the detection and differentiation of medically relevant Candida species. The PCR was improved by generating PCR standards, additional generation of melting curves for species identification and the possibility to investigate different specimens simultaneously