Amblyomma ticks consumed by a giant cowbird, Molothrus oryzivorus.

The removal of ectoparasites is a common behavior found across animal taxa and is a determinant to avoid the negative effects of parasites' presence. Eventually, the elimination of ectoparasites is associated with mutualistic interactions. Cleaner birds remove ectoparasites, providing benefits to its mutualistic host by reducing parasite burden while they obtain a protein food source. Here we report some evidence that giant cowbirds (Molothrus oryzivorus) may have an important role as a cleaner bird. We found 74 adult ticks inside the ventriculus of one male giant cowbird. The ticks belonged to three different species: Amblyomma dubitatum, A. sculptum and A. triste. We found that the sex-ratio of the consumed adult ticks was not different from 1:1. Although additional data are necessary, the large number of ticks found suggests that the giant cowbird may have developed a mutualistic association with large, social mammals such as capybaras (Hydrochoerus hydrochaeris), since this animal is an important host species for the three tick species found in the present study.

Clinical follow-up of patients after a negative digital subtraction pulmonary arteriogram in the evaluation of pulmonary embolism.

PURPOSE: This study was designed to examine the clinical course of patients following digital subtraction pulmonary arteriography (DSPA) interpreted as negative for pulmonary emboli (PE). MATERIALS AND METHODS: Sixty-three patients underwent DSPA interpreted as negative for PE over a 27-month period. Follow-up data were collected by means of medical and diagnostic radiology record review, interviews of referring physicians, and patient telephone interviews. RESULTS: Of 63 patients, two were excluded and seven were lost to follow-up, leaving a study population of 54 patients. Mean follow-up was 12.1 months (range, 0-28.5 months). Thirty-one reported no symptoms of PE. Of 13 patients reporting intermittent chest pain and/or dyspnea during their mean follow-up of 13.6 months, 10 had a history of cardiac, nonthrombotic pulmonary, or gastroesophageal reflux disease. There were no subsequent positive angiograms or ventilation/perfusion scans. Comorbid conditions in the 10 patients who died included cardiac events (n = 4), advanced cancer (n = 2), sepsis/pneumonia (n = 2), sarcoidosis (n = 1), and cerebrovascular accident (n = 1). No documented PE was identified. CONCLUSION: The technique of DSPA is sufficiently sensitive to exclude clinically significant PE. The advantages of image post-processing, in addition to the savings in cost, time, and contrast media, support its use in the angiographic diagnosis of PE.