The Copper/Zinc Ratio Correlates With Markers of Disease Activity in Patients With Inflammatory Bowel Disease.

BACKGROUND: Zinc (Zn) and copper (Cu) are trace elements that serve as cofactors in catalytic processes with impact on immune responses. In patients with inflammatory bowel disease (IBD), decreased levels of serum Zn and Cu have been observed. Here, we investigated the effect of inflammation on serum concentrations of these trace elements in patients with IBD. METHODS: In this cross-sectional study, 98 patients with Crohn disease (CD) and 56 with ulcerative colitis (UC) were prospectively enrolled. Disease activity parameters, such as C-reactive protein (CRP) and fecal calprotectin (FC) were compared to serum Zn, Cu, and Cu/Zn ratio. RESULTS: Zinc insufficiency was observed in 11.2% of patients with CD and 14.3% with UC, Cu insufficiency in 20.4% with CD and 7.1% with UC. Anemia, hypoalbuminemia, increased FC, and elevated CRP were more frequently present in Zn-insufficient patients with IBD. In contrast, lower serum CRP values and a trend to lower FC were observed in Cu-insufficient patients. In multiple linear regression models adjusted for age, gender, and serum albumin, CRP positively correlated with serum Cu (P < 0.001) and the Cu/Zn ratio in both CD and UC (P < 0.001) but not with serum Zn concentrations. FC levels correlated only with the Cu/Zn ratio in patients with UC (P < 0.038). CONCLUSION: Systemic inflammation inversely affected the serum Zn and Cu concentrations and, consequently, resulted in an increased Cu/Zn ratio.

High Prevalence of Vitamin D Deficiency among Patients with Inflammatory Bowel Disease.

BACKGROUND: Vitamin D is a hormone with immunomodulatory properties. Vitamin D deficiency has been reported for patients with inflammatory bowel disease (IBD). In this cross-sectional study, 25-hydroxyvitamin D3 (25-OH-D3) levels in patients with IBD were compared to those in patients with irritable bowel syndrome (IBS). METHODS: A total of 181 patients, 156 with IBD and 25 with IBS, were included. The influence of disease activity, inflammatory markers, physical activity, and season were assessed. RESULTS: A total of 58.6$ (n = 58) of the patients with Crohn's disease (CD) and 44.6$ (n = 25) of the patients with ulcerative colitis (UC) had a 25-OH-D3 level < 50 nmol/L. CD patients showed significantly decreased 25-OH-D3 levels compared to the IBS patients (p = 0.018), but no significant difference was found for UC patients. In a linear regression model adjusted for age, gender, and BMI, a significant inverse association of C-reactive protein (CRP) (p = 0.031) and faecal calprotectin (FC) (p = 0.025) with 25-OH-D3 levels was observed for CD patients. Seasonal variation in 25-OH-D3 levels was found in CD patients, with significantly lower values in spring than in summer (p = 0.04). CONCLUSION: Vitamin D deficiency was common in all IBD patients, but more pronounced in CD patients, in whom it also showed a significant inverse association with inflammatory markers such as CRP and FC.

Erratum: Sheathless hydrodynamic positioning of buoyant drops and bubbles inside microchannels [Phys. Rev. E 84, 036302 (2011)].

This corrects the article DOI: 10.1103/PhysRevE.84.036302.

Effects of intersyringe processing on adipose tissue and its cellular components: implications in autologous fat grafting.

BACKGROUND: Autologous fat grafting is a popular technique in plastic surgery. A mechanical processing method is used to facilitate fat injection. No study has investigated whether this process affects cell quality and preservation of biological functionality. This study analyzed the influence of quick mechanical processing through two interconnected small-diameter syringes ("shuffling") on both structure and viability of fat tissue, and on viability, clonogenicity, and differentiation of the freshly isolated stromal vascular fraction. METHODS: Lipoaspiration was performed in six healthy donors, followed by shuffling the fat either zero, five, or 30 times between two 10-cc syringes. Thereafter, fat was applied through a 1.5-mm cannula as in a clinical setting for autologous fat grafting. Analysis of different treatment conditions was conducted. Immunofluorescent staining allowed assessment of morphology, viability, composition, and damage of the tissue. The stromal vascular fraction was examined for isolation yield, viability, clonogenicity, and differentiation capacity. RESULTS: The process of shuffling changed the macroscopic but not the microscopic structure of the lipoaspirated fat. No difference in cell number, viability, number of lipid droplets, vascular architecture, or ratio of cell composition was found. Analysis of the stromal vascular fraction, apart from large interdonor variability, did not show a significant change in isolation yield, viability, clonogenicity, or adipogenic differentiation capacity of the expanded cells. CONCLUSIONS: The mechanical procedure of shuffling lipoaspirated fat does not alter its tissue viability or its microscopic structure. The absence of impact on the stromal vascular fraction in the assessed parameters suggests that shuffling can be executed according to surgical needs.

Sheathless hydrodynamic positioning of buoyant drops and bubbles inside microchannels.

Particles, bubbles, and drops carried by a fluid in a confined environment such as a pipe can be subjected to hydrodynamic lift forces, i.e., forces that are perpendicular to the direction of the flow. We investigated the positioning effect of lift forces acting on buoyant drops and bubbles suspended in a carrier fluid and flowing in a horizontal microchannel. We report experiments on drops of water in fluorocarbon liquid, and on bubbles of nitrogen in hydrocarbon liquid and silicone oil, inside microchannels with widths on the order of 0.1-1 mm. Despite their buoyancy, drops and bubbles could travel without contacting with the walls of channels; the most important parameters for reaching this flow regime in our experiments were the viscosity and the velocity of the carrier fluid, and the sizes of drops and bubbles. The dependencies of the transverse position of drops and bubbles on these parameters were investigated. At steady state, the trajectories of drops and bubbles approached the center of the channel for drops and bubbles almost as large as the channel, carried by rapidly flowing viscous liquids; among our experiments, these flow conditions were characterized by larger capillary numbers and smaller Reynolds numbers. Analytical models of lift forces developed for the flow of drops much smaller than the width of the channel failed to predict their transverse position, while computational fluid dynamic simulations of the experiments agreed better with the experimental measurements. The degrees of success of these predictions indicate the importance of confinement on generating strong hydrodynamic lift forces. We conclude that, inside microfluidic channels, it is possible to support and position buoyant drops and bubbles simply by flowing a single-stream (i.e., "sheathless") carrier liquid that has appropriate velocity and hydrodynamic properties.