Selective abortion, also called selective maturation, is a phenomenon wherein maternal plants selectively mature ovules that have the potential to grow into higher-quality fruits, such as those that contain more seeds. We hypothesized that the effects of selective maturation on fruit traits could be influenced by the dispersal mechanism. However, to date, limited studies have been conducted on selective maturation in bird-dispersed fruits. Unlike self- or wind-dispersed species, bird-dispersed species would not selectively mature fruits that contain more seeds because they are not preferred by birds. Here, we investigated the effect of selective abortion on the fruit traits of a bird-dispersed species, elderberry (Sambucus racemosa L. subsp. kamtschatica). We performed a flower-removal experiment. Half of the inflorescences on each individual tree were removed for the treatment group, whereas the control group was not manipulated. We found that the flower-removed trees showed higher fruit sets, suggesting the existence of resource limitation. The number of seeds per fruit did not increase by the experimental treatment. Additionally, the control individuals did not produce larger fruits. The lack of effects on fruit traits supported our hypothesis that the effect of selective maturation on fruit traits may differ among species with different dispersal mechanisms.

A 69-year-old man was diagnosed with anastomotic recurrence two and a half years after he underwent lower anterior resection for Stage IIIa upper rectal cancer. In a preoperative examination, contrast-enhanced CT showed a smooth-contour tumor of 2 cm in diameter anterior to the inferior vena cava. The tumor adjoined the inferior part of the third portion of the duodenum and had enlarged over time. FDG positron emission tomography showed abnormal uptake in the tumor. As we considered that the tumor was derived from retroperitoneum tissue, we first performed super-low anterior resection with a diverting ileostomy for anastomotic recurrence. However, endoscopic ultrasonographic fine needle aspiration cytology after surgery strongly suggested that the tumor was an adenocarcinoma. Since no other primary lesions were found, the tumor was diagnosed as recurrence of rectal cancer and was resected at the time of stoma closure. The pathological findings were consistent with metastasis of rectal cancer.

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