Effects of Adrenal Medulla and Sciatic Nerve Co-Grafts in Rats with Unilateral Substantia Nigra Lesions

Major limitations of adrenal medulla transplantation in animal models of Parkinson's disease have been the relatively small behavioral effects and the poor or inconsistent graft survival. Transplantation of fragments of sural nerve in combination with adrenal medulla has been reported to increase the survival of chromaffin cells in adrenal medulla grafts in primates. In the present study, the possibility was tested that peripheral nerve co-grafts would increase the functional effects of adrenal medulla grafts in a 6-hydroxydopamine-lesioned rat model. Animals received unilateral substantia nigra lesions, and subsequently received intraventricular grafts of adrenal medulla, sciatic nerve, adrenal medulla plus sciatic nerve, or sham grafts consisting of medium only. Functional effects of the grafts were tested using apomorphine-induced rotational behavior. The sciatic nerve co-grafts did not increase the survival of TH-immunoreactive chromaffin cells. The co-grafting treatment also did not augment the overall effect of adrenal medulla grafts on rotational behavior. In the animals with substantial numbers of surviving chromaffin cells, however, the animals with sciatic nerve co-grafts showed greater decreases in rotational behavior as compared to the animals with adrenal medulla grafts alone, even though the number of surviving cells was not increased

Adrenal medulla grafts enhance functional activity of the striatal dopamine system following substantia nigra lesions

Adrenal medulla grafts in the lateral ventricle reduce the behavioral manifestations of striatal dopamine depletion in an animal model of Parkinson's disease. Using microdialysis in freely moving rats, the present experiments determined that dopamine was not detectable in cerebrospinal fluid (CSF). However, adrenal medulla grafts were associated with an increase in dopamine turnover and amphetamine-stimulated striatal dopamine release was increased in animals with behaviorally effective adrenal medulla grafts. Therefore, adrenal medulla grafts increase striatal dopamine activity without an appreciable release of dopamine into the CSF. Adrenal medulla grafts also increased serum dopamine concentrations, and the increase in serum dopamine was directly correlated with the behavioral efficacy of the grafts. We suggest that dopamine, produced by adrenal medulla grafts, may gain access to the striatum via the blood supply and then leak out into the host striatum through permeable blood vessels adjacent to the graft. Through this mechanism, adrenal medulla grafts may increase functional dopaminergic activity in the striatum. These results may be important for understanding how autografts of adrenal medulla cells produce a putative alleviation of the symptoms of Parkinson's disease.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27095/1/0000086.pd

Quantitative Analysis of the DNA Methylation Sensitivity of Transcription Factor Complexes

Although DNA modifications play an important role in gene regulation, the underlying mechanisms remain elusive. We developed EpiSELEX-seq to probe the sensitivity of transcription factor binding to DNA modification in vitro using massively parallel sequencing. Feature-based modeling quantifies the effect of cytosine methylation (5mC) on binding free energy in a position-specific manner. Application to the human bZIP proteins ATF4 and C/EBPβ and three different Pbx-Hox complexes shows that 5mCpG can both increase and decrease affinity, depending on where the modification occurs within the protein-DNA interface. The TF paralogs tested vary in their methylation sensitivity, for which we provide a structural rationale. We show that 5mCpG can also enhance in vitro p53 binding and provide evidence for increased in vivo p53 occupancy at methylated binding sites, correlating with primed enhancer histone marks. Our results establish a powerful strategy for dissecting the epigenomic modulation of protein-DNA interactions and their role in gene regulation

A Longitudinal Study of Pediatricians Early in their Careers: PLACES

The American Academy of Pediatrics (AAP) launched the Pediatrician Life and Career Experience Study (PLACES), a longitudinal study that tracks the personal and professional experiences of early career pediatricians, in 2012. We used a multipronged approach to develop the study methodology and survey domains and items, including review of existing literature and qualitative research with the target population. We chose to include 2 cohorts of US pediatricians on the basis of residency graduation dates, including 1 group who were several years out of residency (2002–2004 Residency Graduates Cohort) and a second group who recently graduated from residency at study launch (2009–2011 Residency Graduates Cohort). Recruitment into PLACES was a 2-stage process: (1) random sample recruitment from the target population and completion of an initial intake survey and (2) completion of the first Annual Survey by pediatricians who responded positively to stage 1. Overall, 41.2% of pediatricians randomly selected to participate in PLACES indicated positive interest in the study by completing intake surveys; of this group, 1804 (93.7%) completed the first Annual Survey and were considered enrolled in PLACES. Participants were more likely to be female, AAP members, and graduates of US medical schools compared with the target sample; weights were calculated to adjust for these differences. We will survey PLACES pediatricians 2 times per year. PLACES data will allow the AAP to examine career and life choices and transitions experienced by early-career pediatricians

Accurate and sensitive quantification of protein-DNA binding affinity

Transcription factors (TFs) control gene expression by binding to genomic DNA in a sequence-specific manner. Mutations in TF binding sites are increasingly found to be associated with human disease, yet we currently lack robust methods to predict these sites. Here, we developed a versatile maximum likelihood framework named No Read Left Behind (NRLB) that infers a biophysical model of protein-DNA recognition across the full affinity range from a library of in vitro selected DNA binding sites. NRLB predicts human Max homodimer binding in near-perfect agreement with existing low-throughput measurements. It can capture the specificity of the p53 tetramer and distinguish multiple binding modes within a single sample. Additionally, we confirm that newly identified low-affinity enhancer binding sites are functional in vivo, and that their contribution to gene expression matches their predicted affinity. Our results establish a powerful paradigm for identifying protein binding sites and interpreting gene regulatory sequences in eukaryotic genomes

Crystal and molecular structure of analgesics. II. Dezocine hydrobromide

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44834/1/10870_2005_Article_BF01200881.pd

Canadian Guidelines for Controlled Pediatric Donation After Circulatory Determination of Death-Summary Report

OBJECTIVES: Create trustworthy, rigorous, national clinical practice guidelines for the practice of pediatric donation after circulatory determination of death in Canada. METHODS: We followed a process of clinical practice guideline development based on World Health Organization and Canadian Medical Association methods. This included application of Grading of Recommendations Assessment, Development, and Evaluation methodology. Questions requiring recommendations were generated based on 1) 2006 Canadian donation after circulatory determination of death guidelines (not pediatric specific), 2) a multidisciplinary symposium of national and international pediatric donation after circulatory determination of death leaders, and 3) a scoping review of the pediatric donation after circulatory determination of death literature. Input from these sources drove drafting of actionable questions and Good Practice Statements, as defined by the Grading of Recommendations Assessment, Development, and Evaluation group. We performed additional literature reviews for all actionable questions. Evidence was assessed for quality using Grading of Recommendations Assessment, Development, and Evaluation and then formulated into evidence profiles that informed recommendations through the evidence-to-decision framework. Recommendations were revised through consensus among members of seven topic-specific working groups and finalized during meetings of working group leads and the planning committee. External review was provided by pediatric, critical care, and critical care nursing professional societies and patient partners. RESULTS: We generated 63 Good Practice Statements and seven Grading of Recommendations Assessment, Development, and Evaluation recommendations covering 1) ethics, consent, and withdrawal of life-sustaining therapy, 2) eligibility, 3) withdrawal of life-sustaining therapy practices, 4) ante and postmortem interventions, 5) death determination, 6) neonatal pediatric donation after circulatory determination of death, 7) cardiac and innovative pediatric donation after circulatory determination of death, and 8) implementation. For brevity, 48 Good Practice Statement and truncated justification are included in this summary report. The remaining recommendations, detailed methodology, full Grading of Recommendations Assessment, Development, and Evaluation tables, and expanded justifications are available in the full text report. CONCLUSIONS: This process showed that rigorous, transparent clinical practice guideline development is possible in the domain of pediatric deceased donation. Application of these recommendations will increase access to pediatric donation after circulatory determination of death across Canada and may serve as a model for future clinical practice guideline development in deceased donation