SDF1 Gene Variation Is Associated with Circulating SDF1 alpha Level and Endothelial Progenitor Cell Number-The Bruneck Study

BACKGROUND: Stromal cell-derived factor-1 (SDF1) and its receptor CXC chemokine receptor 4 (CXCR4) play a critical role in progenitor cell homing, mobilization and differentiation. It would be interesting to assess the predictive value of SDF-1alpha level for EPC number, and to ascertain whether there is a relationship between SDF1 gene variation, plasma SDF-1alpha level, and the number and function of circulating EPCs. We also tested whether EPC number and function was related to CXCR4 gene variation. METHODOLOGY AND PRINCIPAL FINDINGS: We genotyped a cohort of individuals who participated in the Bruneck Study for single nucleotide polymorphisms (SNPs) in the SDF1 and CXCR4 genes, and measured blood SDF1alpha level as well as EPC number and function. SDF1alpha levels were correlated with age, gender, alcohol consumption, circulating reticulocyte numbers, and concentrations of matrix metalloproteinase-9, C-reactive protein, cystatin C, fibrinogen and homocytein. In blood samples taken in 2005, EPC number was inversely associated with SDF1alpha level (p<0.001). EPC number in 2005 was also inversely associated with SDF1alpha level in 2000 (p = 0.009), suggesting a predictive value of plasma SDF1alpha level for EPC number. There was an association between the SDF1 gene rs2297630 SNP A/A genotype, increased SDF1alpha level (p = 0.002) and lower EPC number (p = 0.006). CONCLUSIONS: Our data indicate that a SDF1 gene variation (rs2297630) has an influence on SDF1alpha level and circulating EPC number, and that plasma SDF1alpha level is a predictor of EPC number

Stable nanoemulsions for poorly soluble curcumin: From production to digestion response in vitro

Curcumin, a polyphenol, can induce anticancer activity depending on dose. However, oral curcumin administration is limited by its low bioavailability due to aqueous insolubility and instability against physiological conditions. This study aims at formulating nanoemulsions by phase inversion temperature to enhance curcumin loading, stability, antioxidant performance, bioaccessibility, and in vitro absorption. The selection mechanisms for oil phase (coconut oil), surfactant (polyoxyl 40 hydrogenated castor oil), co-surfactant (soy phospholipid), and aqueous phase (2 % wt citrate buffer at pH 4.5) are established. The nanoemulsions show tunable mean droplet size (26–129 nm), high curcumin loading (9.53 ± 0.49 mg/mL), polydispersity 0.05). The curcumin nanoemulsions show ∼ 11 %, 24 %, and 57 % higher retention and ∼ 10 %, 12 %, and 17 % higher antioxidant activity than raw curcumin after 3-hour simulated gastric, intestinal, and physiological incubations, respectively. During in vitro digestion and absorption, the encapsulated curcumin shows higher bioaccessibility and absorption than free curcumin (P < 0.05). The samples are stable during 4-week storage at 4˚C and room temperature without preservatives. These findings suggest the potential to develop a nanoencapsulation strategy, particularly for an oral delivery system of oil-soluble drugs

Resonant peak splitting for ballistic conductance in magnetic superlattices

We investigate theoretically the resonant splitting of ballistic conductance peaks in magnetic superlattices. It is found that, for magnetic superlattices with periodically arranged $n$ identical magnetic-barriers, there exists a general $(n-1)$-fold resonant peak splitting rule for ballistic conductance, which is the analogy of the $(n-1)$-fold resonant splitting for transmission in $n$-barrier electric superlattices (R. Tsu and L. Esaki, Appl. Phys. Lett. {\bf 22}, 562 (1973)).Comment: 9 pages, 3 figures, latex forma