Populations of several species of gregarine parasites within a single host species, the damselfly Ischnura verticalis , were examined over the course of 1 season at 4 geographic localities separated by a maximum distance of 9.7 km. Gregarines, having a life cycle with both exogenous and endogenous stages, are subject to a wide variety of selective pressures that may drive adaptation. Gregarine species showed some specificity for host life cycle stage, i.e., Steganorhynchus dunwoodyi and Hoplorhynchus acanthatholius were most prevalent in larval hosts while Steganorhynchus dunwoodyi, Actinocephalus carrilynnae, and Nubenocephalus nebraskensis were most prevalent in adult hosts. Species prevalence and abundance differed by geographic locality. Gregarine prevalence was significantly higher in adult female damselflies than in males at 2 localities; sex differences in prevalence were insignificant for larval damselflies at all 4 localities. In larval hosts, gregarine abundance was independent of age (size). The present study, therefore, shows that pond characteristics, host life cycle stage, and adult host sex are the main factors that influence the prevalence and abundance of gregarine populations.
Peripheral edema with painful erythema is an increasingly recognized but poorly understood cutaneous adverse reaction to the antifolate agent pemetrexed. It is frequently misdiagnosed as cellulitis, and when it occurs, it is often dose-limiting. The authors report the case of a patient with preexisting lower extremity edema who developed extensive painful, bilateral erythema 5 days after administration of pemetrexed. An eosinophil-rich dermal inflammatory infiltrate was noted histologically. The authors review previously reported cases of pemetrexed-induced pseudocellulitis and discuss possible pathophysiology.
PurposeTo determine the differences in the presentation of ophthalmic giant cell arteritis between African-Americans and Caucasians.MethodsThis was a multicenter retrospective case series comparing African-American patients with ophthalmic GCA to a previously published Caucasian cohort. Neuro-ophthalmic centers across the United States were contacted to provide data on African-American patients with biopsy-proven ophthalmic giant cell arteritis. The differences between African-American and Caucasian patients with respect to multiple variables, including age, sex, systemic and ophthalmic signs and symptoms, ocular ischemic lesions, and laboratory results were studied.ResultsThe Caucasian cohort was slightly older (mean=76.1 years) than the African-American cohort (mean=72.6 years, P=0.03), and there was no difference in sex distribution between the two cohorts. Headache, neck pain, and anemia were more frequent, while jaw claudication was less frequent in African-Americans (P<0.01, <0.001, 0.02, and 0.03 respectively). Acute vision loss was the most common presentation of giant cell arteritis in both groups, though it was less common in African-Americans (78 vs 98% of Caucasians, P<0.001). Eye pain was more common in African-Americans (28 vs 8% of Caucasians, P<0.01).ConclusionsThe presenting features of ophthalmic giant cell arteritis in African-Americans and Caucasians are not markedly different, although a few significant differences exist, including higher rates of headache, neck pain, anemia, and eye pain, and lower rates of jaw claudication and acute vision loss in African-Americans. Persons presenting with suspicious signs and symptoms should undergo evaluation for giant cell arteritis regardless of race.
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