Diverse Responses of Oligodendrocytes to Different FGF-Family Members: Uncoupling Structure-Function Relationship Within FGF Subfamilies.

The fifteen canonical paracrine fibroblast growth factors (FGFs) are organized in five subfamilies that interact with four FGF-receptors (FGFRs) and heparan sulfate proteoglycan (HSPG) co-receptors. Many of these FGFs are expressed in CNS regions where oligodendrocyte (OL) progenitors originate, migrate or differentiate. FGF2 (basic FGF) is considered a prototype FGF and the information about the effects of FGF signaling on OL-lineage cells has evolved largely from the study of FGF2. However, other FGFs from four subfamilies ((FGF1 (FGF1,-2), FGF4 (FGF4,-5,-6), FGF8 (FGF8,-17,-18) and FGF9 (FGF9,-16,-20)) that can interact with the isoforms of FGFRs expressed in OL-lineage cells may also play important roles. We previously reported OL-responses to FGF8 family members. Here, we investigate the effects of members of the FGF1,-4, and -9 subfamilies on proliferation and differentiation of OL progenitors (OPCs), and on cell cycle re-entry and down-regulation of myelin proteins by mature OLs. We found that while FGF2 induced all these responses strongly, FGF4,-6,-9 could do so only transiently and in the presence of exogenous HSPGs, and that FGF5,-16,-20 could not do so even in the presence of heparin or at higher concentrations. Furthermore, we noted that structurally similar FGFs within subfamilies did not always show similarities in their biological effects on OL-lineage cells. Taken together, these studies reveal that FGFs differ in the way they regulate the OL-lineage cells, emphasizes the selectivity and importance of HSPGs as FGF co-receptors in OL-lineage cells and suggests that structural similarity among FGF-subfamily members may not always predict their overlapping biological functions.

Structurally similar members of the FGF1, -4, and -9 subfamilies trigger diverse biological responses in oligodendrocyte-lineage cells and exhibit selective requirement for heparan sulfate proteoglycans as FGF co-receptors.

Population Management: A Tool to Improve Timely Care in Pediatric and Young Adult Patients with Inflammatory Bowel Disease.

BACKGROUND: Maintenance of health leads to better outcomes in patients with chronic illness. ImproveCareNow, an international inflammatory bowel disease (IBD) quality improvement (QI) network, recommends maintenance-of-health visits twice a year. We identified a gap in care, with only 64% of IBD patients having documented visits within 200 days. Therefore, we sought to improve our follow-up rate to a goal of 80%. METHODS: Using population management (PM) reports, we identified patient-, data-, and treatment-related reasons for no documented visit within 200 days. We used the Pareto chart, key drivers, and process flow mapping and implemented changes using Plan-Do-Study-Act (PDSA) cycles to improve follow-up visit rates. Outcomes were presented using a control run chart with pre- and post- intervention data. RESULTS: The most common reasons for no visits were patient nonadherence with appointments (50%) and relocation/transition to an adult provider (25%). The median percentage of documented visits within 200 days increased from 64% to 83% (p < 0.0001), and this increase has been sustained for one year. CONCLUSIONS: Using the PM tool and focused QI interventions improved data quality and the percentage of patients with a documented visit within 200 days. The process is simple and can be applied to patients with other chronic illnesses.

Social interaction and cortisol treatment increase cell addition and radial glia fiber density in the diencephalic periventricular zone of adult electric fish, Apteronotus leptorhynchus.

In electric fish, Apteronotus leptorhynchus, both long-term social interaction and cortisol treatment potentiates chirping, an electrocommunication behavior that functions in aggression. Chirping is controlled by the diencephalic prepacemaker nucleus (PPn-C) located just lateral to the ventricle. Cells born in adult proliferative zones such as the periventricular zone (PVZ) can migrate along radial glial fibers to other brain regions, including the PPn-C. We examined whether social interactions or cortisol treatment influenced cell addition and radial glia fiber formation by (1) pairing fish (4 or 7 days) or (2) implanting fish with cortisol (7 or 14 days). Adult fish were injected with bromodeoxyuridine 3 days before sacrifice to mark cells that were recently added. Other fish were sacrificed after 1 or 7 days of treatment to examine vimentin immunoreactivity (IR), a measure of radial glial fiber density. Paired fish had more cell addition than isolated fish at 7 days, coinciding temporally with the onset of socially induced increase in chirping behavior. Paired fish also had higher vimentin IR at 1 and 7 days. For both cell addition and vimentin IR, the effect was regionally specific, increasing in the PVZ adjacent to the PPn-C, but not in surrounding regions. Cortisol increased cell addition at 7 days, correlating with the onset of cortisol-induced changes in chirping, and in a regionally specific manner. Cortisol for 14 days increased cell addition, and cortisol for 7 days increased vimentin IR but in a regionally non-specific manner. The correlation between treatment-induced changes in chirping and regionally specific increases in cell addition, and radial glial fiber formation suggests a causal relationship between such behavioral and brain plasticity in adults, but this hypothesis will require further testing.