Adipose tissue quantity and composition contribute to adipokine concentrations in the subclavian vein and the inferior mesenteric vein.

BACKGROUND: Adipose tissue dysfunction is associated with inflammation, type 2 diabetes mellitus and vascular diseases. Visceral adipose tissue (VAT)-derived adipokines, which are released in the portal circulation may influence liver metabolism. OBJECTIVES: (1) To estimate the contribution of VAT and subcutaneous adipose tissue (SAT) on adipokine levels by measuring differences in adipokine concentrations between the portal draining inferior mesenteric vein and the subclavian vein. (2) To determine the relation of both VAT and SAT quantity and composition to mesenteric and systemic concentrations of adipokines. DESIGN: Cross-sectional cohort study. SUBJECTS: A total of 32 patients undergoing abdominal aortic surgery. MEASUREMENTS: A panel of 18 adipokines was measured in perioperatively obtained blood samples from the subclavian vein and the inferior mesenteric vein. Adipocyte size, macrophage infiltration and capillary density were measured in subcutaneous and mesenteric adipose tissue biopsies; SAT and VAT areas were measured on computed tomography images. RESULTS: Serum interferon-γ-inducible protein 10 (IP-10) and hepatocyte growth factor (HGF) concentrations were significantly higher in the inferior mesenteric vein vs the subclavian vein. SAT area (ß -18; 95% confidence interval (CI) -35 to -2), subcutaneous adipocyte size (ß -488; 95% CI -938 to -38) and SAT macrophages quantity (ß -1439; 95% CI -2387 to -491) were negatively associated with adiponectin levels in the systemic circulation. SAT area was related to systemic concentrations of leptin. Mesenteric adiponectin concentrations were related to VAT area (ß -20; 95% CI -35 to -5) and visceral adipocyte size (ß -1076; 95% CI -1624 to -527). VAT area, adipocyte size and capillary density were related to systemic adiponectin concentrations. CONCLUSION: SAT and VAT quantities as well as morphologic characteristics of both adipose tissue depots are related to systemic and mesenteric adipokine concentrations. There were no differences in adipokine concentrations between the mesenteric and subclavian vein, except for higher IP-10 and HGF concentrations in the inferior mesenteric vein, indicating a possible contribution of VAT to IP-10 and HGF levels.

Spatial autocorrelation and the scaling of species-environment relationships.

Issues of residual spatial autocorrelation (RSA) and spatial scale are critical to the study of species-environment relationships, because RSA invalidates many statistical procedures, while the scale of analysis affects the quantification of these relationships. Although these issues independently are widely covered in the literature, only sparse attention is given to their integration. This paper focuses on the interplay between RSA and the spatial scaling of species-environment relationships. Using a hypothetical species in an artificial landscape, we show that a mismatch between the scale of analysis and the scale of a species' response to its environment leads to a decrease in the portion of variation explained by environmental predictors. Moreover, it results in RSA and biased regression coefficients. This bias stems from error-predictor dependencies due to the scale mismatch, the magnitude of which depends on the interaction between the scale of landscape heterogeneity and the scale of a species' response to this heterogeneity. We show that explicitly considering scale effects on RSA can reveal the characteristic scale of a species' response to its environment. This is important, because the estimation of species-environment relationships using spatial regression methods proves to be erroneous in case of a scale mismatch, leading to spurious conclusions when scaling issues are not explicitly considered. The findings presented here highlight the importance of examining the appropriateness of the spatial scales used in analyses, since scale mismatches affect the rigor of statistical analyses and thereby the ability to understand the processes underlying spatial patterning in ecological phenomena.

[Isolated orchidodynia as the initial symptom of aneurysm of the abdominal aorta]. / Geïsoleerde orchidodynie als eerste uiting van een aneurysma aortae abdominalis.

A 67-year-old man presented with isolated pain of the right testicle. He was admitted and treated for epididymitis. His symptoms did not improve and lower abdominal pain developed. After hypotension and severe anaemia (Hb 2.1 mmol/l) had developed, abdominal echography was carried out, revealing a ruptured abdominal aortic aneurysm. The patient underwent surgical repair with an aortic-bifemoral prosthesis and was ultimately discharged without further complications. This is the fourth report in the literature of orchidodynia as referred pain from an aneurysm of the abdominal aorta.