Origin of spatial genetic structure in an expanding oak population.

Spatial genetic structure (SGS) results from the interplay of several demographical processes that are difficult to tease apart. In this study, we explore the specific effects of seed and pollen dispersal and of early postdispersal mortality on the SGS of a seedling cohort (N = 786) recruiting within and around an expanding pedunculate oak (Quercus robur) stand. Using data on dispersal (derived from parentage analysis) and mortality (monitored in the field through two growing seasons), we decompose the overall SGS of the cohort into its components by contrasting the SGS of dispersed (i.e. growing away from their mother tree) vs. nondispersed (i.e. growing beneath their mother tree) and initial vs. surviving seedlings. Patterns differ strongly between nondispersed and dispersed seedlings. Nondispersed seedlings are largely responsible for the positive kinship values observed at short distances in the studied population, whereas dispersed seedlings determine the overall SGS at distances beyond c. 30 m. The paternal alleles of nondispersed seedlings show weak yet significantly positive kinships up to c. 15 m, indicating some limitations in pollen flow that should further promote pedigree structures at short distances. Seedling mortality does not alter SGS, except for a slight increase in the nondispersed group. Field data reveal that mortality in this group is negatively density-dependent, probably because of small-scale variation in light conditions. Finally, we observe a remarkable similarity between the SGS of the dispersed seedlings and that of the adults, which probably reflects dispersal processes during the initial expansion of the population. Overall, this study demonstrates that incorporating individual-level complementary information into analyses can greatly improve the detail and confidence of ecological inferences drawn from SGS.

Complete Regression of Giant Inflammatory Polyp after Treatment with Adalimumab.

Giant inflammatory polyps (GIPs) are a rare complication of IBD resulting from chronic regenerative and healing processes leading to a polypoid formation on inflamed mucosa. We reported a case of GIP in a patient with long standing left-sided ulcerative colitis (UC); a well circumscribed sessile GIP was found during a colonoscopy for colorectal cancer screening on a normal colonic mucosa in the cecum. After a severe flare of the left-sided colitis and due to partial response to steroids patient was treated with adalimumab; new colonoscopy after 6 months shows complete disappearance of the GIP previously described. It is the first case report of GIP in normal macroscopic mucosa with complete disappearance after biologic treatment.

Obstructive Giant Inflammatory Polyposis: Is It Related to the Severity or the Duration of the Inflammatory Bowel Disease? Two Case Reports.

We report two cases of giant inflammatory polyposis (GIP) with totally different presentation and evolution. The first patient had two giant pseudopolyps after one year of the diagnosis of UC. The second patient had one obstructive giant pseudopolyp secondary to CD at the level of the transverse colon, being totally asymptomatic years before the presentation. GIP is a rare complication of inflammatory bowel disease (IBD). It consists of numerous filiform polyps that look like a "mass of worms" or a "fungating" mass. Surgical resection is inevitable when GIP presents with obstructive symptoms.