Polyaspartic acid facilitates oxolation within iron(iii) oxide pre-nucleation clusters and drives the formation of organic-inorganic composites.

The interplay between polymers and inorganic minerals during the formation of solids is crucial for biomineralization and bio-inspired materials, and advanced material properties can be achieved with organic-inorganic composites. By studying the reaction mechanisms, basic questions on organic-inorganic interactions and their role during material formation can be answered, enabling more target-oriented strategies in future synthetic approaches. Here, we present a comprehensive study on the hydrolysis of iron(iii) in the presence of polyaspartic acid. For the basic investigation of the formation mechanism, a titration assay was used, complemented by microscopic techniques. The polymer is shown to promote precipitation in partly hydrolyzed reaction solutions at the very early stages of the reaction by facilitating iron(iii) hydrolysis. In unhydrolyzed solutions, no significant interactions between the polymer and the inorganic solutes can be observed. We demonstrate that the hydrolysis promotion by the polymer can be understood by facilitating oxolation in olation iron(iii) pre-nucleation clusters. We propose that the adsorption of olation pre-nucleation clusters on the polymer chains and the resulting loss in dynamics and increased proximity of the reactants is the key to this effect. The resulting composite material obtained from the hydrolysis in the presence of the polymer was investigated with additional analytical techniques, namely, scanning and transmission electron microscopies, light microscopy, atomic force microscopy, zeta potential measurements, dynamic light scattering, and thermogravimetric analyses. It consists of elastic, polydisperse nanospheres, ca. 50-200 nm in diameter, and aggregates thereof, exhibiting a high polymer and water content.

Keratin 9 gene mutations in epidermolytic palmoplantar keratoderma (EPPK).

We have isolated the gene for human type I keratin 9 (KRT9) and localised it to chromosome 17q21. Patients with epidermolytic palmoplantar keratoderma (EPPK), an autosomal dominant skin disease, were investigated. Three KRT9 mutations, N160K, R162Q, and R162W, were identified. All the mutations are in the highly conserved coil 1A of the rod domain, thought to be important for heterodimerisation. R162W was detected in five unrelated families and affects the corresponding residue in the keratin 14 and keratin 10 genes that is also altered in cases of epidermolysis bullosa simplex and generalised epidermolytic hyperkeratosis, respectively. These findings provide further evidence that mutations in keratin genes may cause epidermolysis and hyperkeratosis and that hyperkeratosis of palms and soles may be caused by different mutations in the KRT9 gene.

Combining FIB milling and conventional Argon ion milling techniques to prepare high-quality site-specific TEM samples for quantitative EELS analysis of oxygen in molten iron.

This paper reports a procedure to combine the focused ion beam micro-sampling method with conventional Ar-milling to prepare high-quality site-specific transmission electron microscopy cross-section samples. The advantage is to enable chemical and structural evaluations of oxygen dissolved in a molten iron sample to be made after quenching and recovery from high-pressure experiments in a laser-heated diamond anvil cell. The evaluations were performed by using electron energy-loss spectroscopy and high-resolution transmission electron microscopy. The high signal to noise ratios of electron energy-loss spectroscopy core-loss spectra from the transmission electron microscopy thin foil, re-thinned down to 40 nm in thickness by conventional Argon ion milling, provided us with oxygen quantitative analyses of the quenched molten iron phase. In addition, we could obtain lattice-fringe images using high-resolution transmission electron microscopy. The electron energy-loss spectroscopy analysis of oxygen in Fe(0.94)O has been carried out with a relative accuracy of 2%, using an analytical procedure proposed for foils thinner than 80 nm. Oxygen K-edge energy-loss near-edge structure also allows us to identify the specific phase that results from quenching and its electronic structure by the technique of fingerprinting of the spectrum with reference spectra in the Fe-O system.

Ethosomes for the delivery of anti-HSV-1 molecules: preparation, characterization and in vitro activity.

This paper describes the production, characterization and in vitro activity of ethosomes containing two molecules with antiviral activity, such as acyclovir (ACY) and N1-beta-D-ribofuranosyl-pyrazole [3,4d]pyridazin-7(6p-chlorine-phenyl)-one nucleoside (N1CP). Ethosomes were prepared and morphologically characterized by Cryo-TEM. The encapsulation efficiency was 92.3 +/- 2.5% for ACY and 94.2 +/- 2.8% for N1CP. The release of the drug from vesicles, determined by a Franz cell method, indicated that both drugs were released in a controlled manner. In order to possibly guarantee the stability during long-term storage ethosome suspensions was freeze-dried. It was found that the freeze-dried ethosomes' cakes were compact, glassy characterized by low density and quick re-hydration. However, the storage time slightly influences the percentage of drug encapsulation within ethosomes showing a drug leakage after re-hydration around 10%. The antiviral activity against HSV-1 of both drugs was tested by plaque reduction assay in monolayer cultures of Vero cells. Data showed that ethosomes allowed a reduction of the ED50 of N1CP evidencing an increase of its antiviral activity. However, ACY remains more active than N1CP. No differences are appreciable between drug-containing ethosomes before and after freeze-drying. Taken together these results, ethosomal formulation could be possibly proposed as mean for topical administration of anti-herpetic molecules.

Shear stresses of colloidal dispersions at the glass transition in equilibrium and in flow.

We consider a model dense colloidal dispersion at the glass transition, and investigate the connection between equilibrium stress fluctuations, seen in linear shear moduli, and the shear stresses under strong flow conditions far from equilibrium, viz., flow curves for finite shear rates. To this purpose, thermosensitive core-shell particles consisting of a polystyrene core and a cross-linked poly(N-isopropylacrylamide) shell were synthesized. Data over an extended range in shear rates and frequencies are compared to theoretical results from integrations through transients and mode coupling approaches. The connection between nonlinear rheology and glass transition is clarified. While the theoretical models semiquantitatively fit the data taken in fluid states and the predominant elastic response of glass, a yet unaccounted dissipative mechanism is identified in glassy states.

Blastulae aggregates: new intermediate structures in the micelle-to-vesicle transition of catanionic systems.

A new type of intermediate structure was found in the salt-induced micelle-to-vesicle transition in a catanionic system composed of sodium dodecyl sulfate (SDS) and dodecyltrimethylammonium bromide (DTAB) in aqueous solution with an excess of anionic surfactant. The appearance of symmetrically shaped hollow structures, which we named blastulae vesicles, is presented.

Insights into gliadin supramolecular organization at digestive pH 3.0.

Alpha-gliadin is a highly immunogenic protein from wheat, which is associated with many human diseases, like celiac disease and non-celiac gluten sensitivity. Because of that, gliadin solution is subject to intense biomedical research. However, the physicochemical nature of the employed gliadin solution at physiological pH is not understood. Herein, we present a supramolecular evaluation of the alpha-gliadin protein in water at pH 3.0 by dynamic light scattering (DLS), cryo-transmission electron microscopy (cryo-TEM) and small-angle-.X-ray scattering (SAXS). We report that at 0.5 wt% concentration (0.1 mg/ml), gliadin is already a colloidal polydisperse system with an average hydrodynamic radius of 30 ±â€¯10 nm. By cryo-TEM, we detected mainly large clusters. However, it was possible to visualise for the first time prolate oligomers of around 68 nm and 103 nm, minor and major axis, respectively. SAXS experiments support the existence of prolate/rod-like structures. At 1.5 wt% concentration gliadin dimers, small oligomers and large clusters coexist. The radius of gyration (Rg1) of gliadin dimer is 5.72 ±â€¯0.23 nm with a dimer cross-section (Rc) of 1.63 nm, and an average length of around 19 nm, this suggests that gliadin dimers are formed longitudinally. Finally, our alpha-gliadin 3D model, obtained by ab initio prediction and analysed by molecular dynamics (MD), predicts that two surfaces prone to aggregation are exposed to the solvent, at the C-terminus. We hypothesise that this region may be involved in the dimerisation process of alpha-gliadin.

Influence of composition and preparation parameters on the properties of aqueous monoolein dispersions.

Colloidal cubic phase particles formed in the monoolein/poloxamer/water system are being investigated as potential drug carriers for, e.g., intravenous administration. Preparation methods must, however, still be further developed to reliably yield monoolein dispersions with cubic particles in a size range acceptable for i.v. administration and adequate long-term stability. In this context, the influence of different composition and preparation parameters on the properties of monoolein dispersions prepared by high-pressure homogenization was studied. High pressure homogenization of coarse poloxamer 407-stabilized monoolein/water mixtures leads to dispersions with a large fraction of micrometer-sized particles at low poloxamer concentrations. Higher poloxamer concentrations lead to lower mean particle sizes but the fraction of cubic particles becomes smaller and vesicular particles are observed instead. A study of the characteristics of a dispersion with a standard composition indicated that the homogenization temperature has a much stronger influence on the dispersion properties than the homogenization pressure or the type of homogenizer used. Temperatures around 40-60 degrees C lead to the most favorable dispersion properties. The high temperature sensitivity of the preparation process appears to be at least partly correlated with the phase behavior of the dispersed particles determined by temperature-dependent X-ray diffraction.

Nanosystems for skin hydration: a comparative study.

The present investigation describes a comparative study for the design of innovative topical formulation for skin hydration. In particular, different colloidal forms based on lipidic components have been produced and characterized. Morphology and dimensional distribution have been investigated by means of electron microscopy and photon correlation spectroscopy. Nanoparticulate systems characterized by different morphology and dimensions depending on production procedures have been obtained, namely cubosomes, nanovesicles, solid lipid nanoparticles and liposomes. Hydration power has been studied by means of a corneometer, measuring the skin electrical capacitance before and after the application of opportunely viscosized nanoparticulate systems. It has been demonstrated that nanovesicle gel displayed a pronounced hydration power with respect to the other nanostructured forms, its hydration effect on skin was 3.5-fold higher, with respect to the untreated area, after 5 min from the application and 1.5-fold higher after 2 h.

Characterization of the transcriptional regulatory region of the human WT1 gene.

Specific control of the expression of the Wilms tumor gene WT1 is important for normal development of the kidney. In order to characterise the transcriptional control region of the WT1 gene we have isolated genomic clones spanning the upstream region, the first WT1 exon and the 5' end of the Wit1 gene. DNA sequencing revealed that the WT1 promoter lacks a TATA box or CCAAT motif and has a GC content of 71%. Four transcriptional start sites are clustered within a 32 bp region. GC-boxes are present at nucleotide positions -413, -160, +84 and +158. DNAase I protection assays with purified Sp1 protein revealed the existence of 11 different binding sites in the WT1 promoter. WT1 and Wit1 promoter activities were tested in COS-7 cells with luciferase reporter gene constructs either containing or lacking an SV40 enhancer. WT1 promoter activity was found in a fragment extending from 449 bp upstream to 201 bp downstream of the WT1 start site. It was 26 fold lower in the absence of the SV40 enhancer than in the presence. Cotransfection with a Sp1 expression vector stimulated both constructs 3-4 fold. Wit1 promoter activity was identified in a DNA fragment extending from 200 bp upstream of the putative Wit1 TATA box to 130 bp downstream. Several potential recognition sites for WT1/EGR, Pax-8, and GAGA-like transcription factors are present in the WT1 promoter.

Crystallization behavior of supercooled smectic cholesteryl myristate nanoparticles containing phospholipids as stabilizers.

Supercooled smectic nanoparticles based on physiological cholesterol esters are under investigation as a potential novel carrier system for lipophilic drugs. The present study investigates the very complex crystallization behavior of such nanoparticles stabilized with the aid of phospholipids. Phospholipid and phospholipid/bile salt stabilized cholesteryl myristate dispersions were prepared by high-pressure melt homogenization and characterized by particle size measurements, differential scanning calorimetry, X-ray diffraction and electron microscopy. To obtain fractions with very small smectic nanoparticles, selected dispersions were ultracentrifuged. A mixture of cholesteryl myristate and the phospholipid used for the stabilization of the dispersions was also investigated by light microscopy. The nanoparticles usually display a bimodal crystallization event which depends on the thermal treatment and cannot be attributed to crystalline polymorphism. The ratio of the particle fractions crystallizing in the two successive steps strongly depends on the particle size of the dispersions. The presence of larger particles leads to an increased fraction crystallizing at higher temperature and a higher recrystallization tendency upon storage. The observed peculiarities of the crystallization behavior seem to be mainly caused by the presence of particles with different shapes (cylindrical and spherical) as observed in electron microscopy. Alterations in the composition of the nanoparticles may also play a role.

Energy-filtered cryotransmission electron microscopy of liposomes prepared from human stratum corneum lipids.

We used cryo-TEM to examine the morphology of vesicles formed from lipids of the human stratum corneum (hSC). Human stratum corneum lipid liposomes (hSCLLs) were prepared in buffer at various pH values, using different preparation methods (film method, extrusion, ultrasonication, detergent dialysis). The morphology of hSCLLs at pH 7.4 differed markedly from that of liposomes formed by phospholipids, showing folds, stacks and membrane thickening. At pH 5.0, corresponding to natural conditions at the skin surface, membrane structures are essentially the same as those prepared at pH 7.4. Sharp edges in hSCLLs, branching membranes and stable membrane stacks were explained by the presence of ceramides, the major components and structural elements of human stratum corneum lipids (hSCLs). Thickened areas in the membranes may be caused by the local accumulation of triacylglycerols and cholesterol esters in the hydrophobic interior of the bilayer.

Identification of precipitable Ca2+ by electron spectroscopic imaging and electron energy loss spectroscopy in the organ of Corti of the guinea pig.

Ca2+ cations were precipitated with potassium antimonate in the cochlea of the guinea pig, and the formed precipitates were localized by electron microscopy using either elastically or inelastically scattered electrons. The elemental composition of the precipitates was determined by electron spectroscopic imaging (ESI) and electron energy loss spectroscopy (EELS). It was found that calcium, antimony and oxygen were the dominating elements in the precipitates formed in different cell types in the inner ear.

Steam sterilisation of vesicular phospholipid gels.

Vesicular phospholipid gels (VPGs), highly concentrated phospholipid dispersions of semisolid consistency and vesicular morphology are under investigation as potential implantable depots for sustained release of drugs and as intermediates for subsequent dilution into 'conventional' liposome dispersions. It was investigated here if VPGs can be steam sterilised. VPGs prepared from 400 mg/g egg-phosphatidylcholine by high-pressure homogenisation retained their vesicular structure but showed a slight increase in vesicle size (freeze-fracture electron microscopy). However, autoclaving slowed down both, the in vitro release of the hydrophilic marker carboxyfluorescein and vesicles from VPGs. This was assumed to be due to bigger vesicle sizes and corresponding increase in packing density of the vesicular matrix. Upon dilution into a liposome dispersion both negative staining electron microscopy and dynamic laser light scattering analysis confirmed a distinct increase in liposome size, mainly due to fusion of small (20 nm) vesicles with unfavourable curvature. This was consistent with the observed increase in encapsulation efficiency of carboxyfluorescein. Phospholipid hydrolysis during autoclaving was negligible with lysophosphatidylcholine formation of less than 2% (thin layer chromatography). Despite significant change of their morphological and functional properties during autoclaving VPGs retained their main characteristics, such as vesicular structure, sustained release and dilutability to liposome dispersions, and are, therefore, considered as autoclavable.

Common issues for parents in a methadone maintenance group.

Change has been noted in some of the group members. For example, one long-term group member who never spoke when she was in a previous group that focused on addiction-related problems has become the role model for other members. In this group, she says, she feels more competent. She is appropriately outspoken and has established relationships with her children which consistently underpin the parent-child boundaries that need to be drawn. One specific issue she resolved involved her 19-year-old son and his girlfriend who was pregnant with the group member's grandchild. By role playing the different positions that each of these people held in the home (the group member was paying the rent and had the right to set the rules, the girlfriend was feeling unaccepted by the group member and was acting out inappropriately, and the son was caught between trying to please the two females), the group member was able to clarify for herself how to approach future conflicts. A second member has improved her relationship with her youngest son (age 3) but still struggles with her 15-year-old daughter. What has been most effective for her was teaching her to count to 10 before responding to what she considers the goading of both of her children. In addition, she was feeling pressured by her mother, in whose house she lives, to have her son toilet trained.(ABSTRACT TRUNCATED AT 250 WORDS)

[Evaluation of side effects and complications during the treatment of affective psychoses with thymoleptics]. / Ocena dzialan ubocznych i powiklan podczas leczenia psychoz afektywnych tymoleptykami.

Evaluation of effects of amitriptyline, imipramine, maprotiline, mianserin , clomipramine and citalopram was performed in 84 patients (49 females and 35 males) age on average 40 years with diagnosis of affective psychosis treated in the Department of Psychiatry Medical School of Szczecin. Antidepressants independently from their pharmacological profile cause in above 50% of patients side effects mainly from autonomous nervous system. Tricyclic antidepressants caused some cardiotoxic effects which were not observed during administration of antidepressant drugs of different chemical structure, especially of citalopram. No effects on the haemopoietic system and on parenchymatous organs were observed. Neither were affected hypothalamic mechanisms for basal secretion of thyrotropic hormone, prolactin , cortisol and so ACTH. Multifactorial analysis of positive and untoward effects observed during the treatment shows comparable clinical value of all six evaluated drugs. A choice of a drug for an individual should depend on particular clinical contraindications.

Neutrophilic granulocytes - promiscuous accelerators of atherosclerosis.

Neutrophils, as part of the innate immune system, are classically described to be main actors during the onset of inflammation enforcing rapid neutralisation and clearance of pathogens. Besides their well-studied role in acute inflammatory processes, recent advances strongly indicate a so far underappreciated importance of neutrophils in initiation and development of atherosclerosis. This review focuses on current findings on the role of neutrophils in atherosclerosis. As pro-inflammatory mechanisms of neutrophils have primarily been studied in the microvascular environment; we here aim at translating these into the context of macrovascular inflammation in atherosclerosis. Since much of the pro-inflammatory activities of neutrophils stem from instructing neighbouring cell types, we highlight the promiscuous interplay between neutrophils and platelets, monocytes, T lymphocytes, and dendritic cells and its possible relevance to atherosclerosis.

Colloidal dispersions for the delivery of acyclovir: a comparative study.

This paper describes a comparative study on the performances of ethosomes and solid lipid nanoparticle as delivery systems for acyclovir. Ethosomes were spontaneously produced by dissolution of phosphatidylcholine and acyclovir in ethanol followed by addition of an aqueous buffer while solid lipid nanoparticle were produced by homogenization and ultrasonication. Both colloidal systems were morphologically characterized by cryo-transmission electron microscopy. The encapsulation efficiency was 94.2±2.8% for ethosomes and 53.2±0.2% for solid lipid nanoparticle. Concerning Z potential, both formulations are close to neutrality. The diffusion coefficients of the drug from ethosomes and solid lipid nanoparticle, determined by a Franz cell method, were 9.4 and 1.2-fold lower as compared to the free acyclovir in solution, thus evidencing the ability of both colloidal systems in enhancing the diffusion of the drug. The antiviral activity against HSV-1 of both systems was tested by plaque reduction assay in monolayer cultures of Vero cells. Data showed that no significant differences in the antiviral activity were observed by acyclovir in the free or loaded forms. Taken together these results, colloidal systems could be interesting to mediate the penetration of acyclovir within Vero cells.