Neurogenesis in sea urchin embryos and the diversity of deuterostome neurogenic mechanisms.

A single origin to the diverse mechanisms of metazoan neurogenesis is suggested by the involvement of common signaling components and similar classes of transcription factors. However, in many forms we lack details of where neurons arise, patterns of cell division, and specific differentiation pathway components. The sea urchin larval nervous system is composed of an apical organ, which develops from neuroepithelium and functions as a central nervous system, and peripheral neurons, which differentiate in the ciliary band and project axons to the apical organ. To reveal developmental mechanisms of neurogenesis in this basal deuterostome, we developed antibodies to SoxC, SoxB2, ELAV and Brn1/2/4 and used neurons that develop at specific locations to establish a timeline for neurogenesis. Neural progenitors express, in turn, SoxB2, SoxC, and Brn1/2/4, before projecting neurites and expressing ELAV and SynB. Using pulse-chase labeling of cells with a thymidine analog to identify cells in S-phase, we establish that neurons identified by location are in their last mitotic cycle at the time of hatching, and S-phase is coincident with expression of SoxC. The number of cells expressing SoxC and differentiating as neurons is reduced in embryos injected with antisense morpholino oligonucleotides to SoxC, SoxB2 or Six3. Injection of RNA encoding SoxC into eggs does not enhance neurogenesis. In addition, inhibition of FGF receptors (SU5402) or a morpholino to FGFR1 reduces expression of SoxC. These data indicate that there are common features of neurogenesis in deuterostomes, and that sea urchins employ developmental mechanisms that are distinct from other ambulacraria.

Incidence of Suicide in Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis.

BACKGROUND AND AIMS: Patients with inflammatory bowel disease (IBD) have higher incidence of psychosocial disorders, including depression. As suicide is the most severe manifestation of depression, we sought to identify if patients with IBD have a higher incidence of suicide through a systematic review and meta-analysis. METHODS: Systematic literature searches for articles using EMBASE and MEDLINE using Ovid were conducted to identify studies investigating suicide in IBD. Reference harvesting of the bibliographies of key articles was also performed. We included studies reporting expected number of death or standardized mortality ratio (SMR) for suicide in IBD. Meta-analysis for each IBD condition (Crohn's disease [CD] and ulcerative colitis [UC]) was conducted separately, as well as combined. RESULTS: Seven cohort studies were identified through our search strategy and included in our systematic review and meta-analysis. In our analysis, the SMR for suicide in patients with IBD for all studies included was 1.20 (95% CI, 0.94-1.54). The overall pooled SMR for CD and UC were 1.36 (95% CI, 0.98-1.88) and 1.16 (95% CI, 0.8-1.69) respectively. CONCLUSIONS: Patients with Crohn's disease and ulcerative colitis may have an increased risk of suicide. These results highlight the importance physicians must place on ensuring the mental health of patients with IBD is both assessed and treated appropriately.

Prevalence of Anxiety and Depression in Patients with Inflammatory Bowel Disease.

BACKGROUND: Inflammatory bowel disease (IBD) patients are not routinely screened for depression and anxiety despite knowledge of an increased prevalence in people with chronic disease and negative effects on quality of life. METHODS: Prevalence of anxiety and depression was assessed in IBD outpatients through retrospective chart review. The presence of anxiety and/or depression was determined using the Patient Health Questionnaire-9 and Generalized Anxiety Disorder-7 self-report questionnaires or by diagnosis through psychiatric interview. Patient demographics, disease characteristics, and medication information were also collected. Multivariable analysis was used to determine associations between patient factors and depression and anxiety. RESULTS: 327 patient charts were reviewed. Rates of depression and anxiety were found to be 25.8% and 21.2%, with 30.3% of patients suffering from depression and/or anxiety. Disease activity was found to be significantly associated with depression and/or anxiety (p = 0.01). Females were more likely to have anxiety (p = 0.01). CONCLUSION: A significant proportion of IBD patients suffer from depression and/or anxiety. The rates of these mental illnesses would justify screening and referral for psychiatric treatment in clinics treating this population. Patients with active disease are particularly at risk for anxiety and depression.