פרסומים

AIM: Guaifenesin is a very commonly used and prescribed oral expectorant drug. However, its mechanism of action is not completely elucidated and the available information is limited. The purpose was to evaluate whether guaifenesin action on respiratory tract secretion is mediated through a reflex stimulation of the gastric mucosa or by the systemic exposure due to the absorption of the drug to the blood circulation. METHODS: Guaifenesin was administered to rats by various routes: intravenous bolus, oral gavage, and gastric, jejunal or cecal infusions (through surgically implanted catheters). Phenol red respiratory tract secretion (after intraperitoneal or intravenous injection) was used as a marker for degree of expectorant action. Administration of saline by gavage was used as control. RESULTS: Respiratory secretion following oral bolus was approximately 2-fold higher (p<0.05) than that of control. Following IV administration the increase of respiratory secretion did not occur despite the fact that systemic exposure to guaifenesin was 1.5-fold higher than following oral administration. The abdominal surgery was found to eliminate the effect of guaifenesin although it did not change systemic absorption. Guaifenesin was equally absorbed from all parts of the gastrointestinal tract. CONCLUSIONS: It was demonstrated that expectorant action of guaifenesin is mediated by stimulation of the gastrointestinal tract and not by the systemic exposure to the drug.

Reliable methods of regulating estrus and stimulating superovulations in equine embryo transfer programs are desirable. Our objectives were to investigate the efficacy of a progesterone and estradiol-17beta (P&E) estrus synchronization regimen in mares with and without subsequent equine follicle-stimulating hormone (eFSH) treatment and to examine the effects of eFSH on folliculogenesis and embryo production. Cycling mares were treated with P&E daily for 10 d. On the final P&E treatment day, prostaglandin F(2alpha) was administered, and mares were randomly assigned to one of two treatment groups (n=20 mares/group). In both groups, mares were examined daily by transrectal ultrasonography. In the eFSH group, twice-daily eFSH treatments were initiated at follicle diameter 20 to 25 mm and ceased at follicle > or =35 mm; human chorionic gonadotrophin (hCG) was administered after 36 h. In the control group, eFSH treatments were not given, but hCG was administered at follicle > or =35 mm. Mares were inseminated with fresh semen, and embryo recovery attempts were performed 8 d postovulation. Synchrony of ovulations within each group appeared to be similar. Six mares in the eFSH group failed to ovulate. The eFSH treatment resulted in higher (P<0.05) numbers of preovulatory follicles and ovulations; however, embryo recovery rate did not increase (eFSH 1.0+/-0.4 vs. control 0.95+/-0.1 embryos/recovery attempt), and embryo per ovulation rate was significantly lower (36% vs. 73%). The eFSH-treated mares had significantly higher frequency of nonovulatory follicles (28% vs. 0) and higher periovulatory serum concentrations of estradiol-17beta. Based on our findings, combined P&E and eFSH regimens cannot be recommended for cycling donor mares.

BACKGROUND: Eosinophils are key effector cells in allergy and in other inflammatory diseases. Although they carry out their function in the tissues, no efficient method exists allowing for consistent purification of tissue eosinophils for culture. Rather, studies rely mainly on peripheral blood eosinophils. This study aimed to determine the most efficient protocol for purifying eosinophils from nasal polyp tissue. METHODS: Nasal polyps were obtained from patients undergoing surgical polypectomy. The polyps were minced and enzymatically digested. Surface receptor analysis was performed by flow cytometry. In order to obtain optimal purification, the nasal polyp cell suspension was subjected to two methods of purification: 1) positive magnetic selection of CCR3+cells, or 2) negative selection using CD3/CD14/CD16 magnetic beads. Enriched tissue eosinophils were cultured with or without IL-3, IL-5 or GM-CSF, and their survival was evaluated by flow cytometry. RESULTS: Tissue-derived eosinophils exhibited surface expression of NEC2, DNAM-1, NTBa, 2B4, and CD300a comparable to similarly prepared eosinophils obtained from the peripheral blood of the same patients. Positive selection consistently yielded eosinophils of high purity (>90%) with 63% viability. In contrast, negative selection yielded better viability (88%), reduced purity (66%), and could be utilized for in vitro activation experiments. CONCLUSION: Eosinophils can be purified from nasal polyps. Negative selection appears to be advantageous due to improved viability of the eosinophils, which may be cultured and activated in vitro. This methodology is an important advance in studying tissue eosinophils for further investigations on inflammatory tissue responses.

We demonstrate the electro-activation of funnel waveguides through the quadratic electro-optic effect in paraelectric potassium-lithium-tantalate- niobate. This allows us to achieve electro-optic intensity modulation in a single optical beam, a 1x2 switch, and finally the electrically controlled morphing of a single waveguide into a 1x2 and a 1x4 divider. (C) 2009 Optical Society of America

Uranyl, UO(2)(2+), was electrochemically determined by a phosphate based self-assembled monolayer. A pretreated gold electrode with 2-mercatpoethanol was chemically modified by POCl(3) or POBr(3) to obtain the surface phosphate active sites. The different stages were characterized by reflection-absorption Fourier transform-infrared (FT-IR) spectroscopy, capacity, and X-ray photoelectron spectroscopy (XPS). The electrochemical determination of UO(2)(2+) was accomplished, after preconcentration under open circuit potential, by square wave voltammetry.[on SciFinder (R)]

Uranyl, UO22+, was electrochem. detd. by a phosphate based self-assembled monolayer. A pretreated Au electrode with 2-mercatpoethanol was chem. modified by POCl3 or POBr3 to obtain the surface phosphate active sites. The different stages were characterized by reflection-absorption FTIR spectroscopy, capacity, and XPS. The electrochem. detn. of UO22+ was accomplished, after preconcn. under open circuit potential, by square wave voltammetry. [on SciFinder(R)]

Poly(ethylene glycol) (PEG) was modified with 3-isocyanatopropyltriethoxysilane (IPTS) to obtain PEG-disilane. This monomer was electrochem. polymd. and deposited onto a stainless steel surface to form a thin PEGylated sol-gel film. The monomer was characterized by 1H-NMR and FTIR spectroscopy. The sol-gel film was characterized by absorption-reflection IR spectroscopy (AR-FTIR), energy dispersive X-ray anal. (EDX), cyclic voltammetry (CV), profilometry, SEM and potentiodynamic polarization. AR-FTIR confirmed the formation of a polymer, while the stability of the polymeric film on stainless steel in buffer phosphate was studied by SEM. The polymer was successfully electrodeposited onto 316L coronary stents. Its flexibility was examd. by dilating the coated stents and inspecting it by SEM. The hydrophilic, smooth PEGylated sol-gel coating significantly reduced the activation and adhesion of platelets as compared with the bare stainless steel surface. This coating, which can be applied to complex geometries, such as stents, is likely to serve as an excellent biomaterial. [on SciFinder(R)]

Nonbiodegradable polymer coating based on N-(2-carboxyethyl)pyrrole (PPA) and butyl ester of PPA (BuOPy) were successfully electrodeposited on a stainless steel stent surface using cyclic voltammetry. Chemical composition of the coating was examined by X-ray photoelectron spectroscopy. Polymer stability was examined by immersing the coated stent into 1:1 solution of fetal calf serum:seline solution up to 1 year and implantation subcutaneously in mouse for 1 week. Morphology changes were then recorded by scanning electron microscopy. Paclitaxel loading was carried out by immersion into drug solution and its release was detected by HPLC. The results show that thin (single micrometers), uniform coating with various morphology and hydrophobicity can be created by electrochemical deposition. The polymer did not show significant histopathological or morphological changes in vitro and in vivo. The surface properties allow loading appropriate amounts of paclitaxel and release it slowly up to a month.[on SciFinder (R)]

Recent studies of the minute morphology of the skin by optical coherence tomography revealed that the sweat ducts in human skin are helically shaped tubes, filled with a conductive aqueous solution. This, together with the fact that the dielectric permittivity of the dermis is higher than that of the epidermis, brings forward the supposition that as electromagnetic entities, the sweat ducts could be regarded as low Q helical antennas. The implications of this statement were further investigated by electromagnetic simulation and experiment of the in vivo reflectivity of the skin of subjects under varying physiological conditions (Feldman et al 2008 Phys. Rev. Lett. 100 128102). The simulation and experimental results are in a good agreement and both demonstrate that sweat ducts in the skin could indeed behave as low Q antennas. Thus, the skin spectral response in the sub-Terahertz region is governed by the level of activity of the perspiration system and shows the minimum of reflectivity at some frequencies in the frequency band of 75-110 GHz. It is also correlated to physiological stress as manifested by the pulse rate and the systolic blood pressure. As such, it has the potential to become the underlying principle for remote sensing of the physiological parameters and the mental state of the examined subject.