Anionic block polymerization of β-lactones initiated by potassium solutions, 1. Synthesis of poly(4-methyl-2-oxetanone-block-2-oxetanone)

The block polymerization of 4-methyl-2-oxetanone (β-butyrolactone) with 2-oxetanone (β-propiolactone) proceeds fast with a yield of more than 90%, in the presence of potassium solutions in THF containing 18-crown-6. Poly(4-methyl-2-oxetanone-block-2-oxetanone) polymers having the expected molecular weight and composition are formed by this way. Their glass transition and melting temperatures as well as their melting enthalpies, determined by DSC, show a strict correlation with block polymer composition.     

Exhaled IL-8 in Systemic Lupus Erythematosus with and without Pulmonary Fibrosis

The purpose of this study is to evaluate the relationship between the concentration of interleukin-8 (IL-8) in exhaled breath condensate (EBC) and bronchoalveolar lavage fluid (BALF) with the disease activity score and pulmonary function of systemic lupus erythematosus (SLE) patients with and without pulmonary fibrosis. Thirty-four SLE patients and 31 healthy controls were enrolled and evaluated using high-resolution computed tomography (HRCT), pulmonary function tests, systemic lupus activity measure (SLAM), assessing BALF and EBC. IL-8 levels in BALF and EBC samples were measured with an enzyme-immunosorbent assay kit. The mean (±SEM) IL-8 concentrations in BALF and EBC were higher in SLE patients compared to healthy controls (34.84 ± 95.0 vs. 7.65 ± 21.22 pg/ml, p < 0.001; 3.82 ± 0.52 pg/m vs. 1.7 ± 1.7 pg/ml, p < 0.001, respectively). SLE patients had increased percentage of neutrophils in BALF when compared with control group (1.00 ± 5.99 vs. 0.00 ± 0.56 %, p = 0.0003). Pulmonary fibrosis in HRCT was found in 50 % of SLE patients. The disease activity scored by SLAM was significantly higher and total lung capacity was significantly lower in SLE patients with pulmonary fibrosis (8.00 ± 3.17 vs. 6.00 ± 2.31, p = 0.01; 88.00 ± 28.29 vs. 112.00 ± 21.08 % predicted, p = 0.01, respectively). In SLE patients with pulmonary fibrosis, correlations were found between SLAM and IL-8 concentration in BALF, forced expiratory volume in 1 s and forced vital capacity (r = 0.65, p = 0.006; r = ?0.53, p = 0.035; r = ?0.67, p = 0.006, respectively). Our results indicate that IL-8 plays an important role in the pathogenesis of SLE. An increased concentration of IL-8 according to BALF could be considered as a useful biomarker of SLE activity and pulmonary fibrosis in SLE.     

Anodic Electrodeposition of Chitosan–AgNP Composites Using In Situ Coordination with Copper Ions

Chitosan is an attractive material for biomedical applications. A novel approach for the anodic electrodeposition of chitosan–AgNP composites using in situ coordination with copper ions is proposed in this work. The surface and cross-section morphology of the obtained coating with varying concentrations of AgNPs were evaluated by SEM, and surface functional groups were analyzed with FT-IR spectroscopy. The mechanism of the formation of the coating based on the chelation of Cu(II) ions with chitosan was discussed. The antibacterial activity of the coatings towards Staphylococcus epidermidis ATCC 35984/RP62A bacteria was analyzed using the live–dead approach. The presented results indicate that the obtained chitosan–AgNP-based films possess some limited anti-biofilm-forming properties and exhibit moderate antibacterial efficiency at high AgNP loads.     

Increased Concentration of C-Reactive Protein in Obese Patients with Type 2 Diabetes Is Associated with Obesity and Presence of Diabetes but Not with Macrovascular and Microvascular Complications or Glycemic Control

The purpose of this study was to assess the concentration of C-reactive protein (CRP) in obese type 2 diabetes mellitus (DM2) patients and its association with macrovascular and microvascular complications. The study group consisted of 80 obese DM2 patients, including 20 macrovascular, 20 microvascular, 20 both macrovascular and microvascular, and 20 with no complications patients. The control group comprised 40 normoglycemic subjects—20 obese and 20 of normal body weight. Highly sensitive CRP and metabolic control parameters were assessed. CRP levels in obese diabetes subgroups and normoglycemic obese were similar and significantly higher than those in nonobese controls. No correlation was found between CRP and diabetes control parameters. There was a strong positive correlation between CRP level and body mass index in all groups. A multivariate analysis showed that DM2 and obesity are independent factors increasing CRP levels. Increased concentration of CRP in obese DM2 patients is related to obesity and diabetes itself. The lack of association between CRP and vascular complications remains unclear.     

Green tea protects human osteoblasts from cigarette smoke-induced injury: possible clinical implication

Purpose

Recent reports discuss the altered bone homeostasis in cigarette smokers, being a risk factor for osteoporosis and negatively influencing fracture healing. Cigarette smoke is known to induce oxidative stress in the body via an increased production of reactive oxygen species (ROS). These increases in ROS are thought to damage the bone-forming osteoblasts. Naturally occurring polyphenols contained in green tea extract (GTE), e.g., catechins, are known to have anti-oxidative properties. Therefore, the aim of this study was to investigate whether GTE and especially catechins protect primary human osteoblasts from cigarette smoke-induced damage and to identify the underlying mechanisms.

Methods

Primary human osteoblasts were isolated from patients?? femur heads. Cigarette smoke medium (CSM) was obtained using a gas-washing bottle and standardized by its optical density (OD₃₂₀) at ???=?320?nm. ROS formation was measured using 2??7??dichlorofluorescein diacetate, and osteoblasts?? viability was detected by resazurin conversion.

Results

Co-, pre-, and post-incubation with GTE and catechins significantly reduced ROS formation and thus improved the viability of CSM-treated osteoblasts. Besides GTE??s direct radical scavenging properties, pre-incubation with both GTE and catechins protected osteoblasts from CSM-induced damage. Inhibition of the anti-oxidative enzyme HO-1 significantly reduced the protective effect of GTE and catechins emphasizing the key role of this enzyme in GTE anti-oxidative effect.

Conclusions

Our data suggest possible beneficial effects on bone homeostasis, fracture healing, and bone mineral density following a GTE-rich diet or supplementation.     

Interactions of human serum albumin with meloxicam: Characterization of binding site

Human serum albumin (HSA) is the most prominent protein in plasma. The three-domain design of HSA provides a variety of binding sites for many ligands, including heme, bilirubin and drugs. Here, we report the effect of new generation, non-steroidal anti-inflammatory drug (NSAID) meloxicam on the albumin conformation and ligand binding. In the present work the interaction of meloxicam with HSA in aqueous solution at physiological pH has been investigated through circular dichroism and fluorescence spectroscopy. The strong quenching of the fluorescence clearly indicated that the binding of the drug to HSA changed the microenvironment of tryptophan residue and the tertiary structure of HSA. This was confirmed by the destabilization of the warfarin binding site. CD and fluorescence spectroscopic results showed marked reductions (about 40% decrease in the CD Cotton effect intensity, and ∼15% decrease of the fluorescence intensity) in the affinity of albumin for bilirubin upon meloxicam binding. The strong inhibition of warfarin and ANS bound to protein after meloxicam modification compared with aspirin confirms that the binding site of both drugs is not the same.