Serum levels of pigment epithelium-derived factor (PEDF) are positively associated with acanthosis nigricans in obese adolescents.

INTRODUCTION: Circulating pigment epithelium-derived factor, or serine protease inhibitor F1, is upregulated during adipogenesis, contributing to obesity-induced insulin resistance. Furthermore, pigment epithelium-derived factor is abundant in stage I melanosomes and has been reported to increase pigment granules and the appearance of mature melanosomes in retinal pigment epithelium. As acanthosis nigricans is a well-recognized clinical marker of insulin resistance, we hypothesized that increased pigment epithelium-derived factor might be associated with the generation of acanthosis nigricans. METHODS: Acanthosis nigricans, anthropometric measurements, circulating total PEDF and metabolic profiles were assessed in 28 obese adolescents in a hospital-based obesity clinic. RESULTS: Subjects with acanthosis nigricans (n = 10) showed greater plasma levels of pigment epithelium-derived factor (PEDF) than those without [geometric mean 23.55 (range 15.2-40.2) vs. 9.01 (range 5.5-18.7) µg/ml; P < 0.001]. Although pigment epithelium-derived factor was positively correlated with the homeostasis model assessment for insulin resistance (HOMA-IR) (r = 0.779, P < 0.001; 95% CI 0.573-0.892), as previously reported, for the same degree of insulin resistance, those with acanthosis nigricans exhibited a 2.1-fold (95%CI 2.0-2.3) higher level of pigment epithelium-derived factor. CONCLUSIONS: While acanthosis nigricans is undoubtedly associated with insulin resistance, its appearance is not ubiquitous in patients at any given level of HOMA-IR. The higher levels of pigment epithelium-derived factor in those with acanthosis nigricans compared with those without, with similar levels of resistance, suggest that pigment epithelium-derived factor levels are associated with acanthosis nigricans.

Normalizing eating behavior reduces body weight and improves gastrointestinal hormonal secretion in obese adolescents.

HYPOTHESIS: Retraining obese adolescents to eat more slowly will lead to beneficial changes in circulating concentrations of gastrointestinal satiety hormones. METHODS: Ghrelin and peptide tyrosine-tyrosine were measured during an oral glucose tolerance test, at baseline and at 12 months during a randomized trial assessing the clinical effectiveness of a device (Mandometer) designed to retrain eating behavior. This computerized scale provided real-time feedback during meals in the intervention arm (n = 14) to slow down the speed of eating. The control group (n = 13) received only standard care aimed at improving lifestyle behavior. The Mandometer elicited greater improvements in weight loss than standard care. RESULTS: Compared with baseline, only those using the Mandometer exhibited lower mean levels of fasting ghrelin (48.14 ± 18.47 vs. 68.45 ± 17.78 pg/ml; P = 0.002) and mean ghrelin area under the curve (72.08 ± 24.11 vs. 125.50 ± 29.72 pg/ml × min; P < 0.001) at 12 months. Absolute mean suppression in ghrelin at 60 min was enhanced (-40.50 ± 21.06 vs. -12.14 ± 19.74 pg/ml × min; P = 0.001). Peptide tyrosine-tyrosine response at 90 min remained unaltered in the standard care arm, whereas those in the Mandometer arm increased (P < 0.001): the mean 90-min response increased by 72 pg/ml [95% confidence interval (CI) 52-92 pg/ml] between baseline and 12 months. In a partial correlation analysis adjusting for change (Δ) in body mass index sd scores, Δ meal duration correlated negatively with Δ absolute suppression in ghrelin at 60 min (r = -0.58; P = 0.037; 95% CI -0.79 to -0.27) and Δ ghrelin area under the curve (r = -0.62; P = 0.025; 95% CI -0.81 to -0.31). CONCLUSIONS: Retraining obese adolescents to eat more slowly has a significant impact on the gastrointestinal hormone response to a carbohydrate load, suggesting that externally modifiable eating behaviors actually regulate the hormonal response to food.

Anticorpos anti-rickettsias do grupo da febre maculosa em equídeos e caninos no norte do estado do Paraná, Brasil / Anti rickettsia-antibody for spotted fever group in horses and dogs in the north of Paraná stated, Brazil

The Brazilian Spotted Fever (BSF) is a zoonosis that can be fatal if not trteated. As there are few studies of the BSF in the Paraná State, the occurrence of BSF was serologically investigated in dogs and horses by indirect immunofluorescence assay (IFA), in the North of that State, in animals that are regarded as sentinels for BSF. A total of 241 samples of sera of equine, four of asinine, and 29 of dogs were collected in nine farms of three municipalities in the North of Paraná: Arapongas, Douradina, and Umuarama. From fifteen samples of equine serum with positive titres for RIFI, eight (53.3 percent) had titre of 64 against R. rickettsii, two (13.3 percent) 128 against R. rickettsii, and five (33.3 percent) were reactants for R. parkeri and R. rickettsii, with titres ranging from 64 to 2048, and 128 to 1024, respectively. The results showed that domestic animals, sentinels for BSF, are under low exposition to ticks infected with spotted fever group Rickettsia, indicating low risk of human infection by these agents in the studied area.