Ortho-carbaborane derivatives of indomethacin as cyclooxygenase (COX)-2 selective inhibitors

A series of novel indomethacin analogues with carbaboranes as three-dimensional substitutes for the chlorophenyl ring have been prepared. Their cyclooxygenase (COX) inhibition and enzyme selectivity has been tested and compared to the corresponding adamantyl analogues. Surprisingly, only the ortho-carbaborane derivatives were active compounds. Preliminary biological studies gave an interesting insight into the validity of employing carbaboranes as pharmacophores.     

Pharmacokinetic and -dynamic modelling of G-CSF derivatives in humans

ABSTRACT: BACKGROUND: The human granulocyte colony-stimulating factor (G-CSF) is routinely applied to support recovery of granulopoiesis during the course of cytotoxic chemotherapies. However, optimal use of the drug is largely unknown. We showed in the past that a biomathematical compartment model of human granulopoiesis can be used to make clinically relevant predictions regarding new, yet untested chemotherapy regimen. In the present paper, we aim to extend this model by a detailed pharmacokinetic and -dynamic modelling of two commonly used G-CSF derivatives Filgrastim and Pegfilgrastim. RESULTS: Model equations are based on our physiological understanding of the drugs which are delayed absorption of G-CSF when applied to the subcutaneous tissue, dose-dependent bioavailability, unspecific first order elimination, specific elimination in dependence on granulocyte counts and reversible protein binding. Pharmacokinetic differences between Filgrastim and Pegfilgrastim were modelled as different parameter sets. Our former cell-kinetic model of granulopoiesis was essentially preserved, except for a few additional assumptions and simplifications. We assumed a delayed action of G-CSF on the bone marrow, a delayed action of chemotherapy and differences between Filgrastim and Pegfilgrastim with respect to stimulation potency of the bone marrow. Additionally, we incorporated a model of combined action of Pegfilgrastim and Filgrastim or endogenous G-CSF which interact via concurrent receptor binding. Unknown pharmacokinetic or cell-kinetic parameters were determined by fitting the predictions of the model to available datasets of G-CSF applications, chemotherapy applications or combinations of it. Data were either extracted from the literature or were received from cooperating clinical study groups. Model predictions fitted well to both, datasets used for parameter estimation and validation scenarios as well. A unique set of parameters was identified which is valid for all scenarios considered. Differences in pharmacokinetic parameter estimates between Filgrastim and Pegfilgrastim were biologically plausible throughout. CONCLUSION: We conclude that we established a comprehensive biomathematical model to explain the dynamics of granulopoiesis under chemotherapy and applications of two different G-CSF derivatives. We aim to apply the model to a large variety of chemotherapy regimen in the future in order to optimize corresponding G-CSF schedules or to individualize G-CSF treatment according to the granulotoxic risk of a patient.     

Glycodelin protein and mRNA is downregulated in human first trimester abortion and partially upregulated in mole pregnancy.

Glycodelin (Gd) is a major reproductive glycoprotein and a mediator for immunomodulatory effects directed to cellular, humoral, and innate immunity. Human pregnancy depends on a diversity of physiological processes including modulation of the maternal immunosystem. We evaluated the expression of Gd protein and mRNA in first trimester decidual tissue of normal pregnancies and spontaneous abortion and hydatidiform moles. Furthermore, in vitro experiments on endometrial cancer cells to analyze the effect of human chorionic gonadotropin (hCG) on Gd regulation were performed. In decidual tissue of abortion patients, Gd expression was significantly decreased compared with normal gestation, which was confirmed by in situ hybridization. In mole pregnancy, an upregulation of Gd in the first 8 weeks of pregnancy was present. Gd is a main product of decidual tissue in the first trimester of human pregnancy. Reduced Gd expression in abortive pregnancy could lead to an increased activation of the maternal immunosystem, thus causing rejection of the developing fetus. Moreover, Gd expression in endometrial cancer cells in vitro could be stimulated by addition of hCG. Therefore, we speculate that hCG could be one of the factors regulating Gd expression because hCG is downregulated in women with abortion and upregulated in mole pregnancy. In addition, we found a positive feedback loop in Gd and hCG expression in human pregnancy.     

Regulation of the endosomal SNARE protein syntaxin 7 by colony-stimulating factor 1 in macrophages

Colony-stimulating factor 1 (CSF-1) is the main growth factor controlling the development of macrophages from myeloid progenitor cells. However, CSF-1 also regulates some of the key effector functions of macrophages (e.g., phagocytosis and cytokine secretion). The endosomal SNARE protein syntaxin 7 (Stx7) regulates vesicle trafficking events involved in phagocytosis and cytokine secretion. Therefore, we investigated the ability of CSF-1 to regulate Stx7. CSF-1 upregulated Stx7 expression in primary mouse macrophages; it also upregulated expression of its SNARE partners Vti1b and VAMP8 but not Stx8. Additionally, CSF-1 induced the rapid serine phosphorylation of Stx7 and enhanced its binding to Vti1b, Stx8, and VAMP8. Bioinformatics analysis and results from experiments with kinase inhibitors suggested the CSF-1-induced phosphorylation of Stx7 was mediated by protein kinase C and Akt in response to phosphatidylinositol 3-kinase activation. Based on mutagenesis studies, CSF-1 appeared to increase the binding of Stx7 to its SNARE partners by inducing the phosphorylation of serine residues in the Habc domain and/or “linker” region of Stx7. Thus, CSF-1 is a key regulator of Stx7 expression and function in macrophages. Furthermore, the effects of CSF-1 on Stx7 may provide a mechanism for the regulation of macrophage effector functions by CSF-1.     

A one pot, one step, precision cloning method with high throughput capability

Current cloning technologies based on site-specific recombination are efficient, simple to use, and flexible, but have the drawback of leaving recombination site sequences in the final construct, adding an extra 8 to 13 amino acids to the expressed protein. We have devised a simple and rapid subcloning strategy to transfer any DNA fragment of interest from an entry clone into an expression vector, without this shortcoming. The strategy is based on the use of type IIs restriction enzymes, which cut outside of their recognition sequence. With proper design of the cleavage sites, two fragments cut by type IIs restriction enzymes can be ligated into a product lacking the original restriction site. Based on this property, a cloning strategy called 'Golden Gate' cloning was devised that allows to obtain in one tube and one step close to one hundred percent correct recombinant plasmids after just a 5 minute restriction-ligation. This method is therefore as efficient as currently used recombination-based cloning technologies but yields recombinant plasmids that do not contain unwanted sequences in the final construct, thus providing precision for this fundamental process of genetic manipulation.     

O-phospho-L-serine: a modulator of bone healing in calcium-phosphate cements

Bone substitution materials are seen as an alternative to autogenous bone transplants in the reconstruction of human bone structures. The aim of the present animal study was to evaluate the clinical handling and the conditions of bone healing after the application of a phosphoserine and collagen-I-modified calcium-phosphate cement (Biozement D). The application of phosphoserine is supposed to influence the texture of the extracellular matrix. Standardised bone defects were created in the lower jaw of 10 adult minipigs. These defects were reconstructed with a pasty calcium-phosphate cement mixture. After a healing time of 4 months, the animals were sacrificed. The mandibles of all animals were resected and non-decalcified histological sections of the areas of interest were prepared. The experiment was evaluated by means of qualitative histology and histomorphometry. The hydroxyapatite cement entirely hardened intraoperatively. Modelling and handling of the cement was facile and the margin fit to the host bone was excellent. Histology showed that resorption started in the periphery and proceeded exceptionally fast. The bony substitution, especially in phosphoserine-endowed cements, was very promising. After a healing period of 4 months, phosphoserine cements showed a bone regeneration of nearly two-thirds of the defect sizes. In the applied animal experiment, the newly developed hydroxyapatite collagen-I cement is well suited for bone substitution due to its easy handling, its excellent integration and good resorption characteristics. The addition of phosphoserine is very promising in terms of influencing resorption features and bone regeneration.     

Micromechanics of smooth adhesive organs in stick insects: pads are mechanically anisotropic and softer towards the adhesive surface

Animals have evolved adhesive structures on their legs to cling to the substrate during locomotion. Here we characterise the ultrastructure and mechanical properties of adhesive pads in Carausius morosus (Phasmatodea) using atomic force microscopy (AFM) as well as transmission and scanning electron microscopy (TEM, SEM). The smooth adhesive arolium has a soft cuticle consisting of principal rods, which branch into finer fibres near the surface. Indentation experiments showed that the pad material consists of distinct layers with different mechanical properties. The 100–300 nm thick outermost layer consisting of the cuticulin envelope and the epicuticle is extremely soft and resilient (mean effective Young’s modulus 12 kPa), while the subjacent procuticle is a much stiffer material (mean effective Young’s modulus 625 kPa). AFM contact mode imaging revealed that the cuticle is mechanically anisotropic, which can be explained by its fibrillar inner structure. We propose that the described layered structure of smooth adhesive pads, consisting of materials decreasing in stiffness towards the outer surface, represents a superior design to conform and adhere to substrates with roughnesses at different length scales. This design principle could be easily implemented in technical adhesives, and thus has a potential to inspire biomimetic applications.     

The universal design, operation and maintenance guidelines for farm constructed wetlands (FCW) in temperate climates

This paper comprises the scientific justification for the Farm Constructed Wetland (FCW) Design Manual for Northern Ireland and Scotland. Moreover, this document addresses an international audience interested in applying wetland systems in the wider agricultural context. Farm constructed wetlands combine farm wastewater (predominantly farmyard runoff) treatment with landscape and biodiversity enhancements, and are a specific application and class of integrated constructed wetlands (ICW), which have wider applications in the treatment of other wastewater types such as domestic sewage. The aim of this review paper is to propose guidelines highlighting the rationale for FCW, including key water quality management and regulatory issues, important physical and biochemical wetland treatment processes, assessment techniques for characterizing potential FCW sites and discharge options to water bodies. The paper discusses universal design, construction, planting, maintenance and operation issues relevant specifically for FCW in a temperate climate, but highlights also catchment-specific requirements to protect the environment.     

Study of X-ray and neutron emission in experiments with Al wires in an MA plasma focus

Results are presented from experimental studies of the correlation between X-ray and neutron emissions generated in the implosion of a deuteron plasma shell onto an Al wire. The experiments were carried out on the PF-1000 facility at currents of 1.5–1.8 MA. An Al wire 80 μm in diameter and 7–9 cm in length was placed at the end of the inner electrode. During the implosion of the plasma shell, Al K-shell X-rays were first emitted at the dip of the current derivative. After the X-ray pulse, a relatively stable corona with a diameter of 2–3 mm and lifetime of a few hundred nanoseconds formed around the wire. The presence of the wire did not considerably reduce the total neutron yield (at most 10¹¹ neutrons per shot) in comparison to discharges without a wire. As a rule, the intensity of neutron emission was maximal a few tens of nanoseconds after the peak of X-ray emission. A detailed comparison of two shots with low and high neutron yields have shown that the neutron yield depends on the configuration and dynamics of the discharge. The possible influence of the self-generated axial component of the magnetic field on the development of the plasma focus and the acceleration of fast deuterons is discussed.     

Chaperone-aided in vitro renaturation of an engineered E1 envelope protein for detection of anti-Rubella virus IgG antibodies

The envelope glycoproteins of Rubella virus, E1 and E2, mediate cell tropism, and E1 in particular plays a pivotal role in the fusion of the virus with the endosomal membrane. Both are the prime targets of the humoral immune response. Recombinant variants of the E1 ectodomain as well as E1 antigen preparations from virus lysates are commonly used to detect anti-Rubella immunoglobulins in human sera. Hitherto, recombinant E1 for diagnostic applications has been produced chiefly in eukaryotic expression systems. Here, we report the high-yield overproduction of an engineered E1 ectodomain in the Escherichia coli cytosol and its simple and convenient renaturation into a highly soluble and immunoreactive conformation. C-Terminal fusion to one or two units of the E. coli chaperone SlyD enhances expression, facilitates in vitro refolding, and improves the overall solubility of Rubella E1. As part of this fusion protein, the E1 ectodomain fragment of residues 201-432 adopts an immunoreactive fold, providing a promising tool for the sensitive and specific detection of anti-E1 IgG in Rubella serology. Two disulfide bonds in the membrane-adjacent part of the E1 ectodomain are sufficient to generate conformations with a high and specific antigenicity. The covalently attached chaperone modules do not impair antibody recognition and binding of Rubella E1 when assessed in a heterogeneous immunoassay. SlyD and related folding helpers are apparently generic tools for the expression and refolding of otherwise unavailable proteins of diagnostic or medical importance.