Elevated concentrations of circulating adhesion molecules and their association with microvascular complications in insulin-dependent diabetes mellitus

To better understand potential associations of circulating adhesion molecules (cAMs) with diabetic microangiopathy, circulating serum concentrations of intercellular adhesion molecule-1 (cICAM-1), vascular cell adhesion molecule-1 (cVCAM-1), and endothelial leukocyte adhesion molecule-1 (cELAM-1) were determined in patients with insulin-dependent diabetes mellitus (IDDM) (n = 70) presenting with varying degree of metabolic control and status of diabetic late complications, and were compared with age-matched healthy subjects (n = 70) in a cross-sectional study. Concentrations of cICAM-1 and cVCAM-1 were elevated in IDDM vs. age-matched controls (cICAM-1: 276 +/- 71 vs. 212 +/- 57 ng/mL; P < 0.0001; cVCAM-1: 781 +/- 245 vs. 615 +/- 151 ng/mL; P < 0.0001), whereas cELAM-1 did not differ between the groups (cELAM-1: 50 +/- 25 vs. 46 +/- 23 ng/mL, P = 0.31). The levels of cVCAM-1 were more markedly elevated in IDDM patients with diabetic retinopathy (n = 32) than in those without (n = 38) (cVCAM-1: 848 +/- 281 vs. 724 +/- 197 ng/mL, P < 0.05), as well as in patients with micro- or macroalbuminuria (n = 10) vs. those without (n = 60) (cVCAM-1: 947 +/- 256 ng/mL vs. 753 +/- 234 ng/mL, P < 0.05), whereas no difference in cICAM-1 and cELAM-1 was apparent regarding the clinical status of diabetic microangiopathy. No correlations were found between hemoglobin A1e and cAMs in the individual subgroups of patients and healthy subjects. Interestingly, however, low density lipoprotein cholesterol correlated with cVCAM-1 (r = 0.38, P = 0.03) in IDDM patients with diabetic microangiopathy (n = 33), but not in healthy controls or patients without microangiopathy (n = 37). Analyzing the pooled data of diabetic patients and healthy subjects (n = 140), concentrations of cICAM-1 were markedly related to cVCAM-1 (r = 0.45, P < 0.0001) and cELAM-1 (r = 0.31, P < 0.0002), whereas cVCAM-1 was related less to cELAM-1 (r = 0.19, P = 0.03), respectively. We conclude that, irrespective of actual metabolic control, serum concentrations of cICAM-1 and cVCAM-1 but not cELAM-1 are elevated in patients with IDDM, reflecting ongoing endothelial cell stimulation and leukocyte activation. More specifically, more marked elevation of cVCAM-1 may even hint at clinically manifest diabetic microangiopathy.     

Zum Transport des Kohlenstoffes in plattierten Werkstoffen

Erörterung des Kohlenstofftransports zwischen Grundwerkstoff und Auflage in plattierten Werkstoffen und Messung des Diffusionsausgleiches an betrieblich walzplattierten Blechproben. Beobachtung und Beurteilung der in der Auflage ausgeschiedenen Chromcarbide. Verfolgung der Wirkung von Zwischenschichten aus mit Stickstoff und Silicium angereicherten austenitischen Chrom-Nickel-Stählen auf die Konzentrationsverhältnisse an der Bindeebene. Überprüfung des Verformungsverhaltens plattierter Bleche mit einer Zwischenschicht aus mit rd. 4% Si angereichertem austenitischem Chrom-Nickel-Stahl durch Biegeversuche.     

利用全新的陶瓷方法简化LED散热设计

LED的散热问题将是限制它未来能否在市场上取得更大成功的主要因素。目前业界的很多研究都集中在散热器上,但对LED和散热表面之间的隔层研究较少。     

Stochastic simulation of ligand-receptor interaction

We have developed an algorithm for the stochastic simulation of ligand-receptor interactions based on 10(4)-10(5) fictitious binding sites. Reversible receptor binding was simulated by alternate random selection of sites, the first selection resulting in "occupation" if the selected site was "free," the second selection resulting in "dissociation" if the selected site was "occupied." We show that the mathematical formalism of mass action kinetics is predicted on purely statistical grounds. The model was extended by the introduction of two further selections, simulating a conformational change in the ligand-receptor complex ("receptor isomerization model"). All random selections were gauged separately by "probability barriers," taking the place of macroscopic kinetic rate constants. Simulation of gradual increases and gradual decreases of the fraction of occupied fictitious binding sites in the receptor isomerization model, using various combinations of "rate constants," resulted in biexponential time dependencies, in agreement with predictions from the integrated rate equations. Stochastic simulation of molecular processes is a powerful and versatile technique, providing the researcher with a means of studying mechanisms of increasing complexity.