Block copolymers with bipyridine containing segments: Synthesis and self-organization by Cu(I) complexation

The synthesis and properties of segmented ABA triblock and (AB)_n multiblock copolymer systems with 6,6′-disubstituted 2,2′-bipyridine (bpy) building blocks B and poly(oxytetramethylene) soft segments A are described. The access to the disubstituted bipyridines in large scale quantities was achieved by modification of conventional synthetic routes. In the presence of copper(I) ions these polymers formed mononuclear [Cu(I)(bpy)₂] complexes in solution through self-assembly. The complexed copolymers were microphase separated systems in bulk with nano to mesoscopic superstructures consisting of copper-bpy complex aggregates in a polyether matrix. The thermal, mechanical and elastomer properties of the block copolymers varied with composition.     

Chronic multifocal non-bacterial osteomyelitis in hypophosphatasia mimicking malignancy

Background  

Hypophosphatasia (HP) is characterized by a genetic defect in the tissue-nonspecific alkaline phosphatase (TNSALP) gene and predominantly an autosomal recessive trait. HP patients suffer from reduced bone mineralization. Biochemically, elevated concentrations of substrates of TNSALP, including pyridoxal-5'-phosphate and inorganic pyrophosphate occur in serum, tissues and urine. The latter has been associated with chronic inflammation and hyperprostaglandinism.     

Transient demineralization of the hip--case report]

Transient osteoporosis of the hip is an uncommon disorder of unclear etiology. It is often confused with other diagnosis including osteonecrosis of the femoral head. Authors describe a case of transient osteoporosis of the hip of 32 years woman. The symptoms occurred in third trimester of pregnancy. The primary symptoms were right hip pain and decreased range of motion of the right hip. In diagnostic process helpful were clinical examination, X-ray, ultrasonography, MRI and microscopic examination. As a treatment authors used walking on crutches, calcitonin and calcium preparate. After a few months remission of symptoms and normalization in accessory investigations were obtained.     

Growth promoting and metabolic activity of the human insulin analogue [Gly,Arg,Arg]insulin (HOE 901) in muscle cells

[Gly^A21,Arg^B31,Arg^B32]insulin (HOE 901) represents a biosynthetic human insulin analogue that, due to its isoelectric point, precipitates at neutral tissue pH leading to a retarded absorption rate and a corresponding longer duration of action. In the present investigation we have evaluated the growth promoting and metabolic activity of this analogue in muscle tissue using exponentially growing H9c2 cardiac myoblasts and adult rat ventricular cardiomyocytes. Equilibrium binding studies of ¹²⁵I-labelled IGF-I (insulin-like growth factor I) to differentiating myoblasts revealed the presence of 7×10³ IGF-I receptors per cell. In contrast, no specific binding of insulin could be detected. Competition binding experiments showed a slightly higher affinity of HOE 901 for the IGF-I receptor when compared to regular human insulin with IC₅₀ (half-inhibitory concentration) values of 70 and 101 nM, respectively. However, the supermitogenic insulin analogue [Asp^B10]insulin competed significantly more efficiently for IGF-I binding (IC₅₀: 44 nM). Maximum growth promoting activity of the peptides was then determined in serum-starved myoblasts by an incubation with the peptides (5×10⁻⁷ M) for 16 h in the presence of [³H]thymidine. [Asp^B10]Insulin produced a stimulation of DNA synthesis (about 3-fold) which was comparable to the effect of IGF-I and significantly (P<0.005) higher than the effect of HOE 901 with the latter being essentially equipotent to native insulin. Comparable results were obtained at lower concentrations of the peptides (10⁻⁹ to 10⁻⁸ M). Metabolic activity of HOE 901 was determined by measuring the dose-dependent stimulation of 3-O-methylglucose transport in adult cardiomyocytes. Maximum transport stimulation was identical for insulin and HOE 901 with EC₅₀ (half-effective concentration) values of 0.7×10⁻¹⁰ and 1.9×10⁻⁹ M, respectively. We concluded that the IGF-I receptor-mediated growth promoting activity of HOE 901 in muscle cells and the maximal metabolic activity of this analogue are not different from those of native human insulin. It is suggested that differential interaction with IGF-I receptors significantly contributes to the action profile of insulin analogues.     

The relationship between activity and pain in patients 6 months after lumbar disc surgery: Do pain-related coping modes act as moderator variables?

BACKGROUND: In LBP patients, the relationship between pain and physical activity remains unclear. Whereas a negative relationship between pain and self-reported physical activity was found, this relation disappeared in the case of overt behavioral data (e.g., accelerometer). Cognitive-behavioral models of the development of chronic pain suggest subgroups with signs of physical underuse and overuse. AIMS: To examine if patients with pain-related adaptive, endurance and fear-avoidance coping differ in pain, self-reported physical function and overt physical activity 6 months after disc surgery. METHODS: 24 patients completed questionnaires (Von Korff chronic pain grade (CPG), Kiel pain inventory (KPI), Funktionsfragebogen Hannover-Rücken FFbH-R) and underwent an 8-h accelerometer assessment in their daily life (physical activity level (PAL), number of constant postures (CP)). The KPI differed between adaptive coping (AC) (N=9), fear avoidance coping (FAC) (N=1) and endurance coping (EC) (N=14). RESULTS: In the whole group, pain intensity was negative related to self-reported physical activity whereas PAL and CP displayed no correlation with pain. EC patients showed significantly higher pain scores and lower self-reported physical functioning compared to AC but the same level of PAL and furthermore, a significantly higher number of CPs in daily life. The visual inspection of the FAC patient revealed also high pain, low physical functioning and low overt physical activity. CONCLUSIONS: The assessment of pain-related coping modes yielded an important differentiation between subgroups of LBP patients 6 months after surgery. Endurance copers displayed signs of overuse in their daily behavior in spite of pain than adaptive copers. The one fear avoidance coper tends to do less physical activity in the sense of underuse.     

Complement-opsonized HIV: the free rider on its way to infection

The complement system (C) is one of the main humoral components of innate immunity. Three major tasks of C against invading pathogens are: (i) lysis of pathogens by the formation of the membrane attack complex (MAC); (ii) opsonization of pathogens with complement fragments to favor phagocytosis; and (iii) attraction of inflammatory cells by chemotaxis. Like other particles, HIV activates C and becomes opsonized. To escape complement-mediated lysis, HIV has adopted various properties, which include the acquisition of HIV-associated molecules (HAMs) belonging to the family of complement regulators, such as CD46, CD55, CD59, and the interaction with humoral regulatory factors like factor H (fH). Opsonized virus may bind to complement receptor positive cells to infect them more efficiently or to remain bound on the surface of such cells. In the latter case HIV can be transmitted to cells susceptible for infection. This review discusses several aspects of C-HIV interactions and provides a model for the dynamics of this process.     

Chicks from a high and low feather pecking line of laying hens differ in apomorphine sensitivity

Proactive rodents show a larger behavioral response to apomorphine (APO) than reactive copers, suggesting a more sensitive DA system in proactive individuals. Previously, chicks from a high feather pecking (HFP) and low feather pecking line (LFP) have been suggested to display a proactive and reactive coping strategy, respectively. Therefore, at approximately 4 weeks of age, the behavior of 48 LFP and 48 HFP chicks in response to an APO injection was studied using an open field. Another objective of the present study was to determine whether behavioral variation (in an open field) between HFP and LFP birds, after APO injection, is also reflected by variation of D(1) and D(2) receptor densities in the brain. Receptor binding capacities were assessed by measuring specific binding of tritiated D(1) and D(2) receptor ligands in different regions of the brain of control HFP and LFP chicks. In the present study, it is shown that indeed HFP chicks display a more enhanced behavioral response to acute APO treatment (0.5 mg/kg BW) than LFP birds in an open field. This difference was not reflected by variation of D(1) and D(2) receptor densities in the brain between both lines.     

Fluorescence in situ hybridization BCR/ABL fusion signal rate in interphase nuclei of healthy volunteer donors: a test study for establishing false positive rate

Fluorescence in situ hybridization (FISH) using chromosome-specific DNA probes is rapidly becoming a part of clinical laboratory practice. However, as a relatively new clinical test, it is not yet standardized and for practical reasons each laboratory must establish its own criteria. For this purpose we have evaluated the specificity of a dual-color BCR/ABL translocation probe by establishing the range of BCR/ABL fusion-positive scores in a healthy donor group. The false positive rate (FPR), determined by the percent of FISH BCR/ABL fusion-positive cells found in the specimens of healthy donors, was estimated at 2.3% (mean = 1%-4%). Thus the cut-off value for false positive nuclei was set at 5%.