Proteomic Helicobacter pylori biomarkers discriminative of low-grade gastric MALT lymphoma and duodenal ulcer

To date no reliable diagnostic method exists to predict, among the very large and clinically heterogeneous group of Helicobacter pylori‐infected patients, the extremely small group at risk for developing low‐grade gastric MALT lymphoma (LG‐MALT). Search of proteomic biomarkers holds promise for the classification of the H. pylori strains with regard to this severe clinical outcome. In the present study 69 H. pylori strains isolated from patients with two different H. pylori‐associated diseases, duodenal ulcer (DU, n=29) and LG‐MALT (n=40) were used. Protein expression patterns of the strains were analyzed by using the high‐throughput methodology SELDI. Selected proteins were purified by means of chromatographic and electrophoretic methods in view of further sequencing by LC‐MS/MS. Univariate analysis (Mann–Whitney test) of the protein expression patterns generated nine significant biomarkers that can discriminate between H. pylori strains from patients with DU and LG‐MALT. These biomarkers are of low molecular weight, ranging from 6 to 26.6 kDa. Among them, two are overexpressed in LG‐MALT strains and seven – in DU strains. Two biomarker proteins, one overexpressed in LG‐MALT strains (13.2 kDa) and another one – overexpressed in DU strains (26.6 kDa), were purified to homogeneity and identified by using LC‐MS/MS as a 50S ribosomal protein L7/L12 and a urease subunit, respectively. These biomarkers can be included in novel protein arrays for the differential diagnosis of H. pylori‐associated clinical outcomes.     

Numerical implementation of the asymptotic boundary conditions for steadily propagating 2D solitons of Boussinesq type equations

In the present paper, a difference scheme on a non-uniform grid is constructed for the stationary propagating localized waves of the 2D Boussinesq equation in an infinite region. Using an argument stemming form a perturbation expansion for small wave phase speeds, the asymptotic decay of the wave profile is identified as second-order algebraic. For algebraically decaying solution a new kind of nonlocal boundary condition is derived, which allows to rigorously project the asymptotic boundary condition at the boundary of a finite-size computational box. The difference approximation of this condition together with the bifurcation condition complete the algorithm. Numerous numerical validations are performed and it is shown that the results comply with the second-order estimate for the truncation error even at the boundary lines of the grid. Results are obtained for different values of the so-called ‘rotational inertia’ and for different subcritical phase speeds. It is found that the limits of existence of the 2D solution roughly correspond to the similar limits on the phase speed that ensure the existence of subcritical 1D stationary propagating waves of the Boussinesq equation.     

Encapsulation of urease in double‐layered hydrogels of macroporous poly(2‐hydroxyethyl methacrylate) core and poly(ethylene oxide) outer layer: fabrication and biosensing properties

Double‐layered hydrogels of super‐macroporous poly(2‐hydroxyethyl methacrylate) (PHEMA) cryogel core and poly(ethylene oxide) (PEO) hydrogel outer layer for encapsulation of the enzyme urease were constructed. The enzyme was entrapped into the pores of PHEMA cryogel by soaking and then the core was covered with a PEO layer. The leaking of urease from the core was prevented when the density of the PEO network was increased by incorporation of the crosslinking agent, poly(ethylene glycol) diacrylate. The hybrid system exhibited a nearly constant enzyme activity with time and maintained its structural integrity after several reactions of hydrolysis of urea. The potential of double‐layered hydrogels containing urease for establishment of water pollution with copper was investigated as well. Copyright © 2011 Society of Chemical Industry     

Ontogeny of the testicular excurrent duct system of male Japanese quail (Coturnix japonica): A histological,ultrastructural, and histometric study

The testicular excurrent duct system undergoes several physiological and morphological changes during the reproductive stage or breeding season in mammals, birds, and reptiles. Studies on normal age-related histomorphological changes in the excurrent duct system of Japanese quails (Coturnix japonica) remain unreported, despite the extensive use of this bird as an avian model in research studies. The current study investigated the histological, ultrastructural, and histometric changes in the testicular excurrent duct system of the Japanese quail during three reproductive stages, namely prepubertal, pubertal, and adult. Simple squamous to low cuboidal cells formed the epithelia of the rete testis in prepubertal and pubertal birds, while in adult birds the lining was low cuboidal to cuboidal. In pubertal and adult birds, the nonciliated Type I epithelial cells of the proximal efferent duct displayed a subapical endocytotic apparatus comprising coated pits, coated apical tubules, and endosomes. There was a significant increase (p ≤ .001) in epithelial heights of all ducts of the excurrent duct system in the mature, sexually active, adult birds when compared to the other age groups. The luminal and tubular diameters, and the cross-sectional areas of efferent ducts and the epididymal duct unit increased significantly (p ≤ .001) with age. It is concluded that the morphology and morphometry of the excurrent ducts of the testis of the Japanese quail change as birds mature.     

Preparation of polymeric nanocapsules via nano-sized poly(methoxydiethyleneglycol methacrylate) colloidal templates

Polymeric nanocapsules are attractive devices with a number of potential applications. In the present contribution we describe a method for nanocapsule preparation which is based on the formation of nanosized templates (mesoglobules, prepared from thermo-responsive poly(methoxydiethyleneglycol methacrylate)s, PDEGMA). These mesoglobules were coated with a cross-linked shell formed by pseudo-seeded radical polymerization of either N-isopropylacrylamide or 2-hydroxyethylmethacrylate in the presence of a cross-linking agent. Dissolution and removal of templates were achieved by extensive dialysis against water at temperatures below the LCST of PDEGMA. The obtained nanocapsules were visualized by transmission electron microscopy and their dimensions were determined by dynamic light scattering. The differences in the morphology of the nanocapsules were attributed to the different structures of the cross-linked membranes.     

Formation of mesoglobules in aqueous media from thermo-sensitive poly(ethoxytriethyleneglycol acrylate)

A series of six poly(ethoxytriethyleneglycol acrylate) (PETEGA) homopolymers were synthesized by atom transfer radical polymerization, reversible addition-fragmentation transfer polymerization, and anionic polymerization in order to cover a molecular weight range from 7,000 to 40,000 Da. The polymers exhibited a lower critical solution temperature (LCST) behavior in water, which was observed by the occurrence of a cloud point (CP) at around 35 °C. The transmittance of visible light versus temperature dependence overlapped during the cooling and the heating cycles, showing almost a complete lack of hysteresis. Moreover, instead of the occurrence of an uncontrolled macroscopic phase separation, stable colloidal aggregates (mesoglobules) of narrow distribution in particle size were formed in water at temperatures above the LCST of PETEGA at 1 g L⁻¹ solutions. The dimensions of the mesoglobules ranged from 91 to 235 nm, and particle size was not influenced by the molecular weight of PETEGA. Temperature changes caused considerable variations of the mesoglobules dimensions, which were smaller at higher temperatures. The addition of an anionic surfactant simultaneously increased the CP values by 4–6 °C and lowered the dimensions of the mesoglobules.     

Two‐component “Onionlike” micelles with a PPO core,a PDMAEMA shell and a PEO corona: formation and crosslinking

BACKGROUND: Chemical or physical crosslinking of supramolecular assemblies gives them stability in a wide range of environments. Much attention is paid to multilayer (onion‐like) polymeric micelles because their functionality is higher than classic core‐shell micelles. This work reports on the formation and crosslinking of onion‐like micelles prepared by mixing two different block copolymers containing a crosslinkable poly(dimethylaminoethyl methacrylate) (PDMAEMA) block. RESULTS: Block copolymers of a crosslinkable PDMAEMA block were synthesized by atom transfer radical polymerization of 2‐(dimethylamino)ethyl methacrylate (DMAEMA) from poly(propylene oxide) (PPO) or poly(ethylene oxide) (PEO) macroinitiators. The (PDMAEMA₁₃)‐block‐PPO₆₉‐block‐(PDMAEMA₁₃) triblock formed wormlike core‐shell micelles, which were converted into ellipsoidal onion‐like micelles on mixing with the PEO₄₅‐block‐P(DMAEMA₈‐co‐MMA₄) diblock. Onion‐like micelles were crosslinked by quaternization of DMAEMA units. CONCLUSION: Formation of onion‐like micelles by mixing two different AB (ABA) and B′C block copolymers and their subsequent crosslinking is a valuable approach towards stabilized supramolecular assemblies of a higher complexity and functionality than the individual constitutive components. Copyright © 2008 Society of Chemical Industry     

Entrapment of Saccharomyces cerevisiae cells in u.v. crosslinked hydroxyethylcellulose/poly(ethylene oxide) double-layered gels

Double-layered gels, consisting of hydroxyethylcellulose cryogel core and poly(ethylene oxide) hydrogel shell, were synthesized with u.v. irradiation, using the same photoinitiator, (4-benzoylbenzyl) trimethylammoniumchloride (BBTMAC) for the both layers. The gels were characterized by measuring their rheological parameters, gel fraction yield, the degree of equilibrium swelling and diffusion coefficient. The diffusion coefficients for glucose and ethanol through the hydroxyethylcellulose cryogel were 3.9 × 10^?6 cm²/s and 0.97 × 10^?5 cm²/s, respectively. The applicability of these double-layered gels as carriers for immobilization was investigated by entrapment of Saccharomyces cerevisiae cells. The immobilization efficiency and cell retention were determined in batch fermentation for ethanol production from glucose. The operational stability of the gels was evaluated in batch fermentation with three consecutive runs. The ethanol yield was in the range from 60% to 77% of the theoretical yield.     

Anatomical and surgical aspects of splenic segmentectomies

Cypermethrin is a synthetic pyrethroid that belongs to a group of insecticides with low mammalian toxicity but high insecticidal activity. The present study was designed to investigate the toxicity of cypermethrin on freshly isolated hepatocytes from male and female rats. Hepatocytes were harvested by a collagenase perfusion technique and were exposed to different concentrations of cypermethrin (100, 200, 400, or 800 ng/2 x 10(6) cells) for up to 2 h. Cell viability and the leakage of aspartate transaminase (AST) and alanine transaminase (ALT) were determined throughout the incubation period. The cell viability of the hepatocytes from male and female rats exposed to 400 ng and 800 ng was significantly reduced after 60 and 30 min of incubation, respectively. With cells from female rats, viability was also reduced upon exposure to 200 ng cypermethrin for 2 h. The decrease in cell viability was dose and time dependent. The leakage of ALT and AST was significantly increased with 400 and 800 ng concentrations at 60 and 30 min, respectively. ALT leakage from female hepatocytes was significantly increased at 60 min of incubation with the 200-ng dose, whereas 2 h of incubation was required for the leakage of ALT from the cells of male rats. The present data indicate that cypermethrin has toxic effects on male and female rat hepatocytes in a dose- and time-dependent manner. The data suggest that female rat hepatocytes may be more sensitive to the toxic effects of cypermethrin than male cells.     

Nomographische Approximationsverfahren und ihre Anwendung zur Ermittlung empirischer Zusammenhänge

Ohne Zusammenfassung Schlu? des Aufsatzes aus Heft 3 (1967) S. 91/97.