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Selected AbstractsImplementation of brief alcohol intervention in primary health care: do nurses' and general practitioners' attitudes, skills and knowledge change?DRUG AND ALCOHOL REVIEW, Issue 6 2005MAURI AALTO Abstract Brief alcohol intervention reduces heavy drinking, but its implementation has been challenging. The purpose was to evaluate self-reported changes in attitudes, skills and knowledge regarding brief intervention among nurses and general practitioners (GPs) during an implementation project. A questionnaire survey was used before and after the implementation to all nurses and GPs working at the time in the seven primary health-care centres of the city of Tampere, Finland. Several positive changes indicate an increased amount of knowledge regarding brief intervention among the professionals during the implementation. This was found especially among the nurses. The success in increasing the knowledge can also be seen in a decrease of training needs. Instead, attitudes and skills among the professionals did not seem to develop positively. Increasing motivational skills especially seems to be the future challenge. [source] Effects of solidification structure on tear resistance of Al,7% Si,0.4% Mg cast alloysFATIGUE & FRACTURE OF ENGINEERING MATERIALS AND STRUCTURES, Issue 1 2004S.-W. HAN ABSTRACT The tear resistance behaviour of Al,7% Si,0.4% Mg cast alloys was examined using Kahn-type tear test specimens. Tests were performed for two permanent mould casts with an ordinary dendrite structure and a semi-liquid die cast with a globular cell and fine grain structure. The microstructure of the two permanent mould casts was controlled by the cooling rates and the addition of Ti elements. Tear resistance was evaluated by the ,pop-in' stress, the energies required for crack initiation, UEi and the crack propagation, UEp. Special attention was paid to an effective microstructural parameter for tear resistance improvement. Pop-in, indicating sudden crack extension and arrest, was observed in all specimens. Homogeneous deformation occurs near the notch tip of the semi-liquid die cast, characterized by a refined grain structure. Refinement of the grain size is more effective than that of the dendrite cell size or eutectic Si particle size to increase the energy for crack initiation. Unit propagation energy, UEp, can be converted into a critical stress intensity factor, Kc, which in the semi-liquid die cast was improved due to an increased amount of slant or shear fracture surface. [source] Growth of Thick MgB2 Films by Impinging-Jet Hybrid Physical-Chemical Vapor Deposition,ADVANCED MATERIALS, Issue 2 2008R. Lamborn Thick MgB2 films are grown using a novel impinging-jet hybrid physical-chemical vapor deposition process. An increased amount of the boron source gas generates high growth rates. Superconducting properties of the thick films are comparable to previous results from other processes, which indicate that this is a promising new process for MgB2 deposition for coated conductor applications, such as wires and tapes for MRI magnets. [source] Partial Recovery of Light-Independent Chlorophyll Biosynthesis in the chlL -Deletion Mutant of Synechocystis sp.IUBMB LIFE, Issue 5 2001PCC 680 Abstract A chlL -deletion mutant of Synechocystis sp. PCC 6803 designated as chlL - was unable to make significant amounts of chlorophyll in darkness. However, an apparent pseudorevertant has been generated spontaneously that can synthesize an increased amount of chlorophyll under light-activated heterotrophic growth conditions. Under these conditions, the chlorophyll content in this pseudorevertant was about 20% of that in the wild-type strain and about 4 times more than that in the original and in the recently recreated chlL -deletion mutant. This is paralleled by increased performance of dark-grown cells in terms of chlorophyll fluorescence induction and oxygen evolution rates in the pseudorevertant versus in the original mutant. PCR analysis confirmed that the chlL - pseudorevertant mutant still lacked the chlL gene. These results imply that the light-independent chlorophyll biosynthesis pathway was partly recovered. [source] Effects of level of feed intake and Fusarium toxin-contaminated wheat on rumen fermentation as well as on blood and milk parameters in cowsJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 3-4 2006K. Seeling Summary The aims of this study were to examine the effects of and possible interactions between dry matter (DM) intake and feeding Fusarium toxin-contaminated wheat on ruminal fermentation, serum chemical parameters and milk yield of dairy cows. Fourteen dairy cows equipped with ruminal and duodenal cannulas were analysed. All animals were fed the same ration, the daily feed amounts being adjusted to current performance. On DM basis, the ration consisted of 60% concentrate including 55% wheat [Fusarium -contaminated wheat (mycotoxin period) or control wheat (control period)] and was completed with 40% maize and grass silage. Each cow was fed the contaminated wheat [deoxynivalenol (DON), 8.21 mg/kg DM and zearalenone (ZON), 0.09 mg/kg DM] and the control wheat (0.25 mg DON/kg DM and 51 ,g ZON/kg DM). As expected, a higher organic matter (OM) intake decreased the amounts of fermented crude nutrients related to the respective intakes. An increased amount of crude protein degraded (p < 0.05) and a lower molar percentage of propionate in the rumen fluid were observed when feeding the Fusarium toxin-contaminated wheat at increased OM intakes in comparison with the control wheat. The activities of serum aspartate aminotransferase (ASAT; p < 0.001), glutamate dehydrogenase (GLDH; p < 0.01) and gamma glutamyl transferase (, -GT; p < 0.01) increased with increasing OM intake and were not related to the mycotoxin contamination of the wheat. [source] Increased Bone Formation in Mice Lacking Plasminogen Activators,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 7 2003E Daci Abstract Plasminogen activators tPA and uPA are involved in tissue remodeling, but their role in bone growth is undefined. Mice lacking tPA and uPA show increased bone formation and bone mass. The noncollagenous components of bone matrix are also increased, probably from defective degradation. This study underlines the importance of controlled bone matrix remodeling for normal endochondral ossification. Introduction: Proteolytic pathways are suggested to play a role in endochondral ossification. To elucidate the involvement of the plasminogen activators tPA and uPA in this process, we characterized the long bone phenotype in mice deficient in both tPA and uPA (tPA,/,:uPA,/,). Materials and Methods: Bones of 2- to 7-day-old tPA,/,:uPA,/, and wild-type (WT) mice were studied using bone histomorphometry, electron microscopy analysis, and biochemical assessment of bone matrix components. Cell-mediated degradation of metabolically labeled bone matrix, osteoblast proliferation, and osteoblast differentiation, both at the gene and protein level, were studied in vitro using cells derived from both genotypes. Results: Deficiency of the plasminogen activators led to elongation of the bones and to increased bone mass (25% more trabecular bone in the proximal tibial metaphysis), without altering the morphology of the growth plate. In addition, the composition of bone matrix was modified in plasminogen activator deficient mice, because an increased amount of proteoglycans (2×), osteocalcin (+45%), and fibronectin (+36%) was detected. Matrix degradation assays showed that plasminogen activators, by generating plasmin, participate in osteoblast-mediated degradation of the noncollagenous components of bone matrix. In addition, proliferation of primary osteoblasts derived from plasminogen activator-deficient mice was increased by 35%. Finally, osteoblast differentiation and formation of a mineralized bone matrix were enhanced in osteoblast cultures derived from tPA,/,:uPA,/, mice. Conclusions: The data presented indicate the importance of the plasminogen system in degradation of the noncollagenous components of bone matrix and suggest that the accumulation of these proteins in bone matrix,as occurs during plasminogen activator deficiency,may in turn stimulate osteoblast function, resulting in increased bone formation. [source] Stress kinase p38 mediates EGFR transactivation by hyperosmolar concentrations of sorbitolJOURNAL OF CELLULAR PHYSIOLOGY, Issue 2 2002Hao Cheng Activation of the epidermal growth factor receptor (EGFR) has been shown to occur by ligand-dependent and ligand-independent mechanisms. Different molecular mechanisms have been found to be responsible for ligand-independent receptor transactivation. Here, we show that hyperosmolar concentrations of sorbitol activate the EGFR in human keratinocytes. Experiments using specific inhibitors of EGFR phosphorylation show that the increased amount of activated receptors is the result of a decreased rate of dephosphorylation. Furthermore, sorbitol treatment results in a strong activation of stress kinase p38. Treatment of the cells with SB203580, a known inhibitor of p38 , and , kinases, results in impairment of receptor activation, indicating that the stress kinase is involved in receptor activation modulation. This is further reinforced by experiments showing that addition of Toxin B, known to be an inhibitor of the small Rho GTPases rac1, cdc42, and Rho A/B, to the cells results in a strong induction of EGFR activation. Our results point, therefore, to a mechanism by which osmotic shock activates EGFR through the small Rho GTPases-p38 stress kinase pathway. © 2002 Wiley-Liss, Inc. [source] STRATEGIES FOR PROLONGING THE SHELF LIFE OF MINCED BEEF PATTIESJOURNAL OF FOOD SAFETY, Issue 1 2009MATTEO ALESSANDRO DEL NOBILE ABSTRACT The study of different strategies for prolonging the shelf life of fresh minced beef patties was addressed in this work. Fresh minced beef was supplemented with thymol (THY) at levels of 250, 500 and 750 mg per kg of ground beef. Treated samples were packed using a high barrier film and stored in refrigerated conditions (4C) under ordinary atmosphere packaging and modified atmosphere packaging (MAP) conditions for 16 days. The microbiological quality decay kinetic was determined by monitoring the following microorganisms: Enterobacteriaceae, Pseudomonas spp., lactic acid bacteria, Brochothrix thermosphacta, coliforms and total psychrotrophic viable count. Results show that THY, working alone, was effective on coliforms and Enterobacteriaceae, whereas it does not seem to inhibit to a great extent the growth of the other microbial populations. On the other hand, an increased amount of THY, under MAP conditions, had better effects on the product quality, with a consequent prolongation of the shelf life. PRACTICAL APPLICATIONS Great interest is developing in food bio-preservation, because of the ever-increasing needs to protect consumers' health and to valorize the naturalness and safety of food products. However, very few works have been carried out on the applications of bio-preservatives to extend the shelf life of fresh meat products. This study, therefore, was mainly initiated to evaluate the possibility of extending the shelf life of packed fresh meat patties by a combination of thymol (THY) to other extrinsic factors such as storage temperatures and modified atmosphere during packaging. Interesting results were obtained suggesting that THY can perform an efficient synergy with modified atmosphere conditions and could be advantageously utilized by the meat industry. [source] Down-regulation of protein l -isoaspartyl methyltransferase in human epileptic hippocampus contributes to generation of damaged tubulinJOURNAL OF NEUROCHEMISTRY, Issue 3 2002Julie Lanthier Abstract Protein l -isoaspartyl methyltransferase (PIMT) repairs the damaged proteins which have accumulated abnormal aspartyl residues during cell aging. Gene targeting has elucidated a physiological role for PIMT by showing that mice lacking PIMT died prematurely from fatal epileptic seizures. Here we investigated the role of PIMT in human mesial temporal lobe epilepsy. Using surgical specimens of hippocampus and neocortex from controls and epileptic patients, we showed that PIMT activity and expression were 50% lower in epileptic hippocampus than in controls but were unchanged in neocortex. Although the protein was down-regulated, PIMT mRNA expression was unchanged in epileptic hippocampus, suggesting post-translational regulation of the PIMT level. Moreover, several proteins with abnormal aspartyl residues accumulate in epileptic hippocampus. Microtubules component ,-tubulin, one of the major PIMT substrates, had an increased amount (two-fold) of l -isoaspartyl residues in the epileptic hippocampus. These results demonstrate that the down-regulation of PIMT in epileptic hippocampus leads to a significant accumulation of damaged tubulin that could contribute to neuron dysfunction in human mesial temporal lobe epilepsy. [source] Pregnenolone Sulfate, a Naturally Occurring Excitotoxin Involved in Delayed Retinal Cell DeathJOURNAL OF NEUROCHEMISTRY, Issue 6 2000C. Cascio Abstract: The present study was designed to investigate the neurosteroid pregnenolone sulfate (PS), known for its ability to modulate NMDA receptors and interfere with acute excitotoxicity, in delayed retinal cell death. Three hours after exposure of the isolated and intact retina to a 30-min PS pulse, DNA fragmentation as assessed by genomic DNA gel electrophoresis and a modified in situ terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) method appeared concurrently with an increase in superoxide dismutase (SOD) activity and thiobarbituric acid-reactive substances (TBARS) levels. At 7 h, the increased amount of DNA laddering was accompanied by a higher number of TUNEL-positive cells in the inner nuclear and ganglion cell layers. Necrotic signs were characterized by DNA smear migration, lactate dehydrogenase (LDH) release, and damage mainly in the inner nuclear layer. PS-induced delayed cell death was markedly reduced by the NMDA receptor antagonists 4-(3-phosphonopropyl)-2-piperazinecarboxylic acid and 3,-hydroxy-5,-pregnan-20-one sulfate but completely blocked after concomitant addition of the non-NMDA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione. Steroids with antioxidant properties (progesterone, dehydroepiandrosterone and its sulfate ester, and 17,-estradiol) differently prevented PS-induced delayed cell death. Cycloheximide treatment protected against DNA fragmentation and LDH release but failed to prevent the rise in SOD activity and TBARS level. We conclude that a brief PS pulse causes delayed cell death in a slowly evolving apoptotic fashion characterized by a cycloheximide-sensitive death program downstream of reactive oxygen species generation and lipid peroxidation, turning into secondary necrosis in a retinal cell subset. [source] Safety of cesarean myomectomyJOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 5 2009Byung-Joon Park Abstract Aim:, To examine the safety and appropriateness of uterine myomectomy during cesarean section. Methods:, We conducted a retrospective analysis of 97 patients who underwent myomectomy during cesarean section and 60 patients who had uterine myomas, but underwent cesarean section only, between January 2000 and December 2007. Based on the patients' medical records, we conducted an analysis of the characteristics of the uterine myomas, hematologic changes that occurred between the preoperative and postoperative phases, complications, and length of hospital stay. Results:, Changes in hemoglobin values between the preoperative and postoperative phases, indicating the degree of intraoperative bleeding, were evaluated. There were no significant differences between the two groups (cesarean myomectomy group [1.2 ± 1.2 g/dL] versus control group [1.1 ± 1.3 g/dL]). There were no significant differences in the frequency of blood transfusion, incidence of postoperative fever, duration of surgery, and length of hospital stay between the two groups. In patients who received a blood transfusion intraoperatively, the increased amount was added to the hemoglobin changes between the preoperative and postoperative phases (adjusted value). The difference in the adjusted value of hemoglobin change did not reach statistical significance (cesarean myomectomy group [1.3 ± 1.2 g/dL] versus control group [1.2 ± 1.1 g/dL]). When the size of the uterine myoma exceeded 6 cm, the operative time was longer in the cesarean myomectomy group. Conclusion:, Cesarean myomectomy is a safe surgical option with no significant complications if performed by an experienced practitioner. [source] Local alendronate increases fixation of implants inserted with bone compaction: 12-week canine studyJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 4 2007Thomas Jakobsen Abstract Bone compaction has been shown to increase initial implant fixation. Furthermore, bone compaction creates a peri-implant zone of autograft that exerts osteoconductive properties. We have previously shown that locally applied bisphosphonate (alendronate) at 4-week observation can preserve the autograft generated by bone compaction. We now investigate whether the increased amount of autograft, seen at 4 weeks, can increase implant osseointegration and biomechanical fixation. Porous-coated titanium implants were bilaterally inserted with bone compaction into the proximal part of tibia of 10 dogs. On the right side, local bisphosphonate was injected into the bone cavity prior to bone compaction immediately prior to implant insertion. On the left side, saline was used as control. Observation period was 12 weeks. Locally applied bisphosphonate significantly increased biomechanical implant fixation (approximately twofold), bone-to-implant contact (1.2-fold), and peri-implant bone volume fraction (2.3-fold). This study indicates that local alendronate treatment can increase early implant osseointegration and biomechanical fixation of implants inserted by use of bone compaction. Long term effects remain unknown. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:432,441, 2007 [source] Activation of MMP-2 by Porphyromonas gingivalis in human periodontal ligament cellsJOURNAL OF PERIODONTAL RESEARCH, Issue 2 2003Kassara Pattamapun It has been reported that matrix metalloproteinase (MMP) produced by host cells plays a major role in periodontal tissue destruction. In addition, secreted virulence factors from Porphyromonas gingivalis can alter MMP secretion and cause activation in host cells that lead to the tissue degradation. In this study, we examine the effects of P. gingivalis supernatant on matrix metalloproteinase-2 (MMP-2) activation in human periodontal ligament (HPDL) cells. Cultures of HPDL cells were treated with P. gingivalis supernatant for 48 h and the level of MMP-2 activation was monitored by gelatin zymography. The profound activation of MMP-2 was seen only in the treated group. The activation of MMP-2 was inhibited by MMP inhibitors phenanthroline and EDTA, but not serine protease or cysteine protease inhibitors. To study the correlation between the expression of membrane-type-1 matrix metalloproteinase (MT1-MMP) and the activation of MMP-2, the level of MT1-MMP was analyzed. The results from reverse-transcription polymerase chain reaction (RT-PCR) and Western analysis indicated that P. gingivalis supernatant up-regulated the expression of MT1-MMP in both transcription and translation levels within 48 h. These results suggest that P. gingivalis supernatant can activate MMP-2 in HPDL cells and the mechanism of activation may involve the increased amount of MT1-MMP. It is possible that the activation of MMP-2 by P. gingivalis plays a role in the process of chronic periodontitis. [source] CHANGES IN THE MORPHOLOGY AND POLYSACCHARIDE CONTENT OF MICROCYSTIS AERUGINOSA (CYANOBACTERIA) DURING FLAGELLATE GRAZING,JOURNAL OF PHYCOLOGY, Issue 3 2008Zhou Yang To investigate the changes in the morphology and polysaccharide content of Microcystis aeruginosa (Kütz.) Kütz. during flagellate grazing, cultures of M. aeruginosa were exposed to grazing Ochromonas sp. for a period of 9 d under controlled laboratory conditions. M. aeruginosa responded actively to flagellate grazing and formed colonies, most of which were made up of several or dozens of cells, suggesting that flagellate grazing may be one of the biotic factors responsible for colony formation in M. aeruginosa. When colonies were formed, the cell surface ultrastructure changed, and the polysaccharide layer on the surface of the cell wall became thicker. This change indicated that synthesis and secretion of extracellular polysaccharide (EPS) of M. aeruginosa cells increased under flagellate grazing pressure. The contents of soluble extracellular polysaccharide (sEPS), bound extracellular polysaccharide (bEPS), and total polysaccharide (TPS) in colonial cells of M. aeruginosa increased significantly compared with those in single cells. This finding suggested that the increased amount of EPS on the cell surface may play a role in keeping M. aeruginosa cells together to form colonies. [source] Alkyl halides reactions with cathodes or with magnesium.JOURNAL OF PHYSICAL ORGANIC CHEMISTRY, Issue 12 2006Grignard reagent studied with radical clocks. Abstract In the mechanism of reaction of Grignard reagent formation for alkyl halides (RX), it is generally assumed that the alkyl radical, formed by the electron transfer from the metal to this halide, reacts rapidly with the paramagnetic MgX, species. The previous comparisons of aryl halides reactivity toward magnesium and their reactivity toward a cathode strongly suggested that MgX, species are not, for the aryl halides, compulsory to rationalise the observed facts. The aryl radicals formed by electron transfer from the metal to the aryl halide would undergo a rapid second electron transfer to yield carbanions transformed into RMgX by reaction with MgX2. In contrast, for the alkyl halides, the reduction of the rapidly formed alkyl radicals into carbanions has seldom been discussed as a possible fate for these radicals, the main discussed fates being dimerisation, disproportionation, hydrogen abstraction from the solvent, rearrangement or coupling with MgX, radicals. Two main differences distinguish the reactivity of alkyl halides from their aryl halides counterpart. First, the radical anions of aryl halides may have a given lifetime whereas electron transfer to alkyl halides is concerted with the cleavage of the molecule. Second, the aryl radicals display far stronger oxidising properties than the alkyl radicals. The counterpart of this property is that aryl carbanions display weaker reducing properties than the alkyl ones. In this report, putting in perspective Grignard reaction and the experimental results obtained with identical radical clocks in electrochemistry, we tentatively provide an answer to the question raised in the title. The comparison of electrochemical patterns of reactivity of selected alkyl halides and the evolutions of yields in the preparation of Grignard reagent suggest a new explanation for the lower yields generally observed when alkyl iodides are the starting substrates. It involves an autocatalytic reaction where carbanionic species formed from the alkyl radicals and diffusing away from the metal surface, transfer one electron to the alkyl halide; the result would be the creation of two radicals leading to an increased amount of by-products. If the carbanionic mechanism were to be retained for the formation of alkyl Grignard reagent one would have to admit that the magnesium surface behaves as a cathode displaying high current densities reminiscent of microelectrodes. Copyright © 2006 John Wiley & Sons, Ltd. [source] Physicochemical, rheological, and organoleptic characteristics of wheat-fenugreek supplemented blendsMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 4 2003Shalini Hooda Abstract The effect of blending of fenugreek (raw, soaked, and germinated) flour (Trigonella faenum graecum) from 5 to 20% in wheat flour on the rheological and sensory evaluation of bread, biscuit, noodle, and macroni was studied. Farinograph water absorption, dough development time, mixing tolerance index, and dough stability increased significantly with increased amount of fenugreek flour. Incorporation of fenugreek flour in wheat flour increased the protein and fat contents of blends but decreased the gluten contents. Among the supplemented blends, blends containing germinated fenugreek flour had higher protein contents (13.83,16.30%) up to 20%. Overall acceptability scores of bread, biscuit, noodles, and macroni were found highly acceptable up to 15, 10, and 20% levels, respectively. [source] Cell-free fetal DNA concentration in plasma of patients with abnormal uterine artery Doppler waveform and intrauterine growth restriction,a pilot studyPRENATAL DIAGNOSIS, Issue 5 2003Elisabetta Caramelli Abstract Objective To evaluate if an increased amount of fetal DNA concentration can be found in women screened positive for intrauterine growth restriction because of abnormal uterine artery Doppler waveforms. Methods We enrolled eight pregnant women (each bearing a male fetus), with the evidence of abnormal uterine artery Doppler waveforms, and 16 control patients for a case-control study matched for gestational age (1 : 2). Uterine artery Doppler was carried out at 20 to 35 weeks' gestation (median 29). The mean uterine artery resistance index (RI) was subsequently calculated, and a value >0.6 was considered positive for the clinical features of pre-eclampsia. The SRY locus was used to determine the amount of male fetal DNA in the maternal plasma at the time of Doppler analysis. Results Two controls (normal Doppler) were excluded from the final analysis because they had a pre-term delivery. One case (abnormal Doppler) had evidence of intrauterine growth restriction at the time of enrolment. In four out of eight cases (abnormal Doppler), intrauterine growth restriction was subsequently observed. Multiples of median (MoM) conversion of the fetal DNA values showed an increase of 1.81 times in the cases when compared to the controls. An increase of 2.16 times was instead observed for the cases with a growth-restricted fetus (5 cases out of 8) in comparison with the controls (14 cases). Conclusions In subjects positive to uterine artery Doppler velocimetry analysis (Doppler analysis for pre-eclampsia screening), the fetal DNA concentration is higher than expected, in the absence of any other clinical feature. Since the increase in fetal DNA seems to be related to the presence or to the future development of intrauterine growth restriction, this paper suggests a possible integration between ultrasound and molecular markers for predicting the disease in some cases. Copyright © 2003 John Wiley & Sons, Ltd. [source] Iron, Manganese and Copper Equilibria with Wood Fibres in Single Salt Aqueous SuspensionsTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 3 2005Robin Susilo Abstract Ions of Fe, Mn and Cu were introduced into suspensions of protonated or metal-free fibres and the equilibrium concentration of each metal in the fibre and surrounding solution was measured. The results were compared with the Donnan equilibrium model. Mn and Cu concentrations on the fibres were found to be pH dependent and in agreement with the model. An increased amount of Fe on the Kraft pulp fibres was found and attributed to iron containing precipitates trapped within the fibres. Precipitates in mechanical pulps had a very small amount (1-2 wt%) of iron. Des ions de Fe, Mn et Cu ont été introduits dans des suspensions de fibres protonatées ou « sans métaux » et la concentration d'équilibre de chaque métal dans la fibre et la solution environnante a été mesurée. Les résultats ont été comparés avec le modèle d'équilibre de Donnan. On a trouvé que les concentrations de Mn et Cu sur les fibres étaient dépendantes du pH et en accord avec le modèle. Une quantité accrue de Fe a été trouvée sur les fibres de pâte kraft et attribuée aux précipitats contenant du fer retenus dans les fibres. Les précipitats dans les pâtes mécaniques ont une très petite quantité (1-2% en poids) de fer. [source] Connexin abundance in resistance vessels from the renal microcirculation in normo- and hypertensive ratsAPMIS, Issue 4 2009THOMAS HARTIG BRAUNSTEIN The expression of connexins in renal arterioles is believed to have a profound impact on conducted responses, regulation of arteriolar tonus and renal blood flow. We have previously shown that in renal preglomerular arterioles, conducted vasomotor responses are 40% greater in spontaneously hypertensive rats (SHR) than in normotensive Sprague,Dawley (SD) rats. Because conducted vasomotor responses depend on the cell,cell communication mediated through gap junctions, we hypothesized that the increased magnitude of conducted vasomotor response in SHR is associated with an increased amount of connexins in renal arterioles. To test this hypothesis, the amount of connexin 37 (Cx37), Cx40 and Cx43 was assessed in renal arterioles from normo- and hypertensive rats using quantitative immunofluorescence laser confocal miscroscopy. To account for differences in genetic background, we included both normotensive Wistar,Kyoto (WKY) and SD rats in the study. In all three strains of rats, and for all three isoforms, the expression of connexins was predominantly confined to the endothelial cells. We found a significantly increased abundance (240 ± 17.6%, p<0.05) of Cx37 in arterioles from WKY compared with SD and SHR. This high abundance of Cx37 was not related to blood pressure because normotensive SD demonstrated a level of Cx37 similar to that of SHR. Additionally, we found no evidence for an increased abundance of Cx40 and Cx43 in renal arterioles of SHR when compared with normotensive counterparts. [source] Quantitive evaluation of macromolecular crystallization experiments using 1,8-ANS fluorescenceACTA CRYSTALLOGRAPHICA SECTION D, Issue 8 2010David Watts Modern X-ray structure analysis and advances in high-throughput robotics have allowed a significant increase in the number of conditions screened for a given sample volume. An efficient evaluation of the increased amount of crystallization trials in order to identify successful experiments is now urgently required. A novel approach is presented for the visualization of crystallization experiments using fluorescence from trace amounts of a nonspecific dye. The fluorescence images obtained strongly contrast protein crystals against other phenomena, such as precipitation and phase separation. Novel software has been developed to quantitatively evaluate the crystallization outcome based on a biophysical metric correlated with voxel protein concentration. In >1500 trials, 85.6% of the successful crystallization experiments were correctly identified, yielding a 50% reduction in the number of `missed hits' compared with current automated approaches. The use of the method in the crystallization of three previously uncharacterized proteins from the malarial parasite Plasmodium falciparum is further demonstrated. [source] Intracellular Na+ and Ca2+ modulation increases the tensile properties of developing engineered articular cartilageARTHRITIS & RHEUMATISM, Issue 4 2010Roman M. Natoli Objective Significant collagen content and tensile properties are difficult to achieve in tissue-engineered articular cartilage. The aim of this study was to investigate whether treating developing tissue-engineered cartilage constructs with modulators of intracellular Na+ or Ca2+ could increase collagen concentration and construct tensile properties. Methods Inhibitors of Na+ ion transporters and stimulators of intracellular Ca2+ were investigated for their ability to affect articular cartilage development in a scaffoldless, 3-dimensional chondrocyte culture. Using a systematic approach, we applied ouabain (Na+/K+ -ATPase inhibitor), bumetanide (Na+/K+/2Cl, tritransporter inhibitor), histamine (cAMP activator), and ionomycin (a Ca2+ ionophore) to tissue-engineered constructs for 1 hour daily on days 10,14 of culture and examined the constructs at 2 weeks or 4 weeks. The gross morphology, biochemical content, and compressive and tensile mechanical properties of the constructs were assayed. Results The results of these experiments showed that 20 ,M ouabain, 0.3 ,M ionomycin, or their combination increased the tensile modulus by 40,95% compared with untreated controls and resulted in an increased amount of collagen normalized to construct wet weight. In constructs exposed to ouabain, the increased percentage of collagen per construct wet weight was secondary to decreased glycosaminoglycan production on a per-cell basis. Treatment with 20 ,M ouabain also increased the ultimate tensile strength of neo-tissue by 56,86% at 4 weeks. Other construct properties, such as construct growth and type I collagen production, were affected differently by Na+ modulation with ouabain versus Ca2+ modulation with ionomycin. Conclusion These data are the first to show that treatments known to alter intracellular ion concentrations are a viable method for increasing the mechanical properties of engineered articular cartilage and identifying potentially important relationships to hydrostatic pressure mechanotransduction. Ouabain and ionomycin may be useful pharmacologic agents for increasing tensile integrity and directing construct maturation. [source] Mechanism of tyrosinase inhibition by deoxyArbutin and its second-generation derivativesBRITISH JOURNAL OF DERMATOLOGY, Issue 6 2008S. Chawla Summary Background, Disorders, such as age spots, melasma and hyperpigmentation at sites of actinic damage, emanate from the augmentation of an increased amount of epidermal melanin. Objectives, The ineptness of current therapies in treating these conditions, as well as high cytotoxicity, mutagenicity, poor skin penetration and low stability of skin-depigmenting formulations led us to investigate new compounds that meet the medical requirements for depigmentation agents. We have shown previously that the tyrosinase inhibitor deoxyArbutin (dA) is a more effective and less toxic skin lightener than hydroquinone (HQ). Methods, The efficacy and reversibility of dA and its derivatives on inhibiting tyrosine hydroxylase and DOPAoxidase was assessed using standard assays. Results, dA and its second-generation derivatives inhibit tyrosine hydroxylase and DOPAoxidase activities of tyrosinase dose dependently thereby inhibiting melanin synthesis in intact melanocytes, when used at concentrations that retain 95% cell viability in culture. This depigmenting effect was completely reversible when the compounds were removed. Tyrosinase inhibition was also observed in vitro when tested using human and purified mushroom tyrosinase, establishing that they are direct enzyme inhibitors. Lineweaver,Burk reciprocal plot analysis using mushroom tyrosinase illustrated that dA and its derivatives are more robust competitive inhibitors than HQ, when tyrosine is used as substrate. Conclusions, Thus, dA and its second-generation derivatives, which inhibit melanogenesis at safe concentrations by specifically acting on the tyrosinase enzyme at a post-translational level, are promising agents to ameliorate hyperpigmented lesions or lighten skin. [source] 3422: Sources of straylight in the human eyeACTA OPHTHALMOLOGICA, Issue 2010D DE BROUWERE Purpose Besides refractive aberrations, ocular light scattering is a major parameter affecting image quality on the retina in healthy eyes. Several pathologies in the anterior segment such as corneal scarring and cataract cause significant increase of straylight in the eye. In this study, we link morphologic changes addressed to corneal scarring to a scattering function. Methods Excised rabbit corneas with different grades of scarring following photorefractive keratectomy were optically evaluated for their forward light scattering distribution and consecutively prepared for histology. An absolute parameter for forward scattering was calculated based on the readings in the optical device. We compared this parameter to the relative thickness of the scar tissue observed in the histological data. Results The histological data showed a wide variation of thickness a scar tissue layer in the anterior stroma. The scattering ratio measured using the optical device measuring forward light scattering correlated strongly with the relative thickness of the scar tissue layer with (0.63, Pearson's coefficient), as well as a standard haze exam (measuring backscattered light) (0.51, Pearson's coefficient). The light scattering distribution is narrowly forward peaked (FWHM 30 arcmin), suggesting this light scattering is caused by large particles such as myofibroblasts, oedema or irregular scar tissue in the ablated zone. Conclusion Corneal light scattering associated with the increased amount of haze after excimer laser ablation has a narrowly forward distribution that can be attributed to the subepithelial structures observed in treated corneas. This is in contrast to the origin of scatterers linked to cataract, as small protein aggregates and multilamellar bodies that are scattering over wider angles. [source] Pd0 -Mediated Rapid Coupling between Methyl Iodide and Heteroarylstannanes: An Efficient and General Method for the Incorporation of a Positron-Emitting 11C Radionuclide into Heteroaromatic Frameworks,CHEMISTRY - A EUROPEAN JOURNAL, Issue 45 2009Masaaki Suzuki Prof. Abstract The Pd0 -mediated rapid trapping of methyl iodide with an excess amount of a heteroaryl-substituted tributylstannane has been investigated with the aim of incorporating a short-lived 11C-labelled methyl group into the heteroaromatic carbon frameworks of important organic compounds, such as drugs with various heteroaromatic structures, in order to execute a positron emission tomography (PET) study of vital systems. The reaction was first performed by using our previously developed CH3I/stannane/[Pd2(dba)3]/P(o -CH3C6H4)3/CuCl/K2CO3 (1:40:0.5:2:2:2) system in DMF at 60,°C for 5,min (conditions A), however, the reaction gave low yields for various heteroaromatic compounds. Increasing the amount of phosphine ligand (conditions B) led to a significant improvement in the yield, but the conditions were still not suitable for a range of basic heteroaromatic structures. Use of the CuBr/CsF system (conditions C) also provided a result similar to that obtained under conditions B with an increased amount of the phosphine. Thus, pyridine and related heteroaromatic compounds remained less reactive substrates. The problem was overcome by replacing the DMF solvent with N -methyl-2-pyrolidinone (NMP). The reaction in NMP at 60,100,°C for 5,min using a CH3I/stannane/[Pd2(dba)3]/P(o -CH3C6H4)3/CuBr/CsF (1:40:0.5:16:2:5) combination (conditions D) gave the methylated products in yields of more than 80,% (based on the reaction of CH3I) for all of the heteroaromatic compounds listed in this study. Thus, the combined use of NMP and an increased amount of phosphine is important for promoting the reaction efficiently. The use of this general approach to rapid methylation has been well demonstrated by the synthesis of the PET tracers 2- and 3-[11C]methylpyridines by using [Pd2(dba)3]/P(o -CH3C6H4)3/CuBr/CsF (1:16:2:5) in NMP at 60,°C for 5,min, which gives the desired products in HPLC analytical yields of 88 and 91,%, respectively. [source] Selective induction of nerve growth factor and brain-derived neurotrophic factor by LPS and allergen in dendritic cellsCLINICAL & EXPERIMENTAL ALLERGY, Issue 3 2008O. Noga Summary Background Neurotrophins are produced by various cells upon different stimuli and participate in the initiation and regulation of inflammation in various diseases including allergy and asthma, but little is known about the production and control of neurotrophins by dendritic cells (DCs). The aim of this study was to assess whether DCs produce the neurotrophins nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF), and whether inflammatory stimuli or allergens are able to induce the production of neurotrophic factors. Methods Monocyte-derived dendritic cells (MoDCs) were generated from different donors. The neurotrophins NGF and BDNF were demonstrated by RT-PCR, Western blotting, flow cytometry analysis and fluorescence microscopy. MoDCs were cultured and stimulated with lipopolysaccharide (LPS) or allergen for 24 h. The supernatants and cells were collected. Measurement for NGF and BDNF was performed by ELISA. Results DCs express mRNA for the neurotrophins NGF and BDNF. Proteins were detectable by Western blot, FACS analysis and fluorescence microscopy. LPS led to an up-regulation of BDNF, while NGF was unaffected. Cell lysates demonstrated an increased amount of BDNF after stimulation with LPS or allergen, while NGF was not affected significantly. Conclusions DCs are a source of neurotrophins. LPS selectively regulates the production of BDNF. Allergen stimulation leads to an LPS-independent regulation. This contributes to a complex involvement of neurotrophins in allergic diseases. [source] Teenage and adult tonsillectomy: dose,response relationship between diathermy energy used and morbidityCLINICAL OTOLARYNGOLOGY, Issue 5 2007A.A.J. Cardozo Objective:, To determine whether an increase in the use of bipolar diathermy energy to perform a tonsillectomy is associated with an increase in postoperative pain and haemorrhage. Study design:, Prospective study. Setting:, District General Hospital. Methods:, In all, 101 patients above the age of 13 years who underwent a tonsillectomy that involved the use of bipolar diathermy during the study period were included. The cumulative amount of diathermy energy used to perform each tonsillectomy was calculated with the help of a digital stop clock timing device connected to the diathermy foot-pedal. Main outcome measures:, Postoperative pain scores and the incidence of secondary haemorrhage were recorded for each patient at four points in time following surgery, up to the tenth postoperative day. The haemorrhage rates were categorised into three groups (no bleeding, minor bleeding and major bleeding) according to severity. Associations between the diathermy energy used to perform each tonsillectomy and the corresponding postoperative pain scores and secondary bleeding rates were investigated. Results:, There was a statistically significant positive relationship between the total amount of bipolar diathermy energy used per tonsillectomy and the pain scores at all the four recorded points in time (rs = 0.44,0.72, P < 0.001). When the median energy consumption in the three groups (no bleeding, minor bleeding and major bleeding) were compared using the Kruskal,Wallis test, we found that there was limited evidence of a difference between the groups, but this was not statistically significant at the 5% level [H (2) = 5.374, P = 0.065, 99% CI 0.058,0.071]. Conclusions:, Increased use of bipolar diathermy during the performance of a tonsillectomy is associated with a statistically significant increased amount of postoperative pain. The dose,response relationship between diathermy energy and postoperative bleeding is less clear. This suggests that there could be other important factors such as surgical instrument characteristics and degree of tonsillar adherence that have an additional influence and are therefore possible areas for future research. [source] Bentazon triggers the promotion of oxidative damage in the Portuguese ricefield cyanobacterium Anabaena cylindrica: Response of the antioxidant systemENVIRONMENTAL TOXICOLOGY, Issue 5 2010Victor Galhano Abstract Rice fields are frequently exposed to environmental contamination by herbicides and cyanobacteria, as primary producers of these aquatic ecosystems, are adversely affected. Anabaena cylindrica is a cyanobacterium with a significantly widespread occurrence in Portuguese rice fields. This strain was studied throughout 72 h in laboratory conditions for its stress responses to sublethal concentrations (0.75,2 mM) of bentazon, a selective postemergence herbicide recommended for integrated weed management in rice, with special reference to oxidative stress, role of proline and intracellular antioxidant enzymes in herbicide-induced free radicals detoxification. Activities of antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), and glutathione S -transferase (GST) increased in a time- and herbicide dose-response manner and were higher than those in the control samples after 72 h. A time- and concentration-dependent increase of malondialdehyde (MDA) levels and the enhanced cell membrane leakage following bentazon exposure are indicative of lipid peroxidation, free radicals formation, and oxidative damage, while increased amounts of SOD, CAT, APX, GST, and proline indicated their involvement in free radical scavenging mechanisms. The appreciable decline in the reduced glutathione (GSH) pool after 72 h at higher bentazon concentrations could be explained by the reduction of the NADPH-dependent glutathione reductase (GR) activity. The obtained results suggested that the alterations of antioxidant systems in A. cylindrica might be useful biomarkers of bentazon exposure. As the toxic mechanism of bentazon is a complex phenomenon, this study also adds relevant findings to explain the oxidative stress pathways of bentazon promoting oxidative stress in cyanobacteria. © 2010 Wiley Periodicals, Inc. Environ Toxicol, 2010. [source] Chemical composition, functional properties and baking potential of African breadfruit kernel and wheat flour blendsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 2 2004Peter I. Akubor Summary The chemical composition and functional properties of African breadfruit kernel flour (ABKF), wheat flour (WF) and their blends were determined. Cookies prepared from the blends were evaluated for their protein contents, physical and sensory characteristics. The flour blends had higher protein, fat and ash contents than WF. The level of these nutrients improved with increased amounts of ABKF in the blends. Foaming, water and oil absorption capacities of the flour blends increased, while the foam stability decreased with increased level of ABKF. The protein contents of the composite flour cookies were higher than that of the all WF cookie. There were no significant differences (P > 0.05) in the flavour of the composite flour cookies and that of all WF cookies. However, sensory scores differed significantly (P < 0.05) amongst them for colour, texture and overall acceptability. [source] Pulmonary responses and recovery following single and repeated inhalation exposure of rats to polymeric methylene diphenyl diisocyanate aerosolsJOURNAL OF APPLIED TOXICOLOGY, Issue 6 2002Joanne D. Kilgour Abstract Acute and repeated inhalation exposures (for 28 days) to polymeric methylene diphenyl diisocyanate (PMDI) were performed in rats. Investigations were made at the end of exposures and after 3, 10 and 30 days of recovery following single acute exposures and after 30 days of recovery following 28 days of exposure. Acute exposures to 10, 30 or 100 mg m,3 PMDI produced clinical signs in all animals that were consistent with exposure to irritant aerosols. An exposure concentration-related body weight loss and increase in lung weight were seen post-exposure, with complete recovery by day 8. The time course of changes in the lung over the initial days following exposure consisted of a pattern of initial toxicity, rapid and heavy influx of inflammatory cells and soluble markers of inflammation and cell damage, increased lung surfactant, a subsequent recovery and epithelial proliferative phase and, finally, a return to the normal status quo of the lung. During these stages there was evidence for perturbation of lung surfactant homeostasis, demonstrated by increased amounts of crystalline surfactant and increased number and size of lamellar bodies within type II alveolar cells. Repeated exposure over 28 days to the less toxic concentrations of 1, 4 or 10 mg m,3 PMDI produced no clinical signs or body weight changes, but an increase in lung weight was seen in animals exposed to 10 mg m,3, which resolved following the 30-day recovery period. Other effects seen were again consistent with exposure to irritant aerosols, but were less severe than those seen in the acute study. Analysis of bronchoalveolar lavage fluid revealed similar changes to those seen in the acute study. At both 10 and 4 mg m,3 PMDI increased numbers of ,foamy' macrophages in lung lavage cell pellet correlated with the increased phospholipid content of the pellet. Changes in lung lavage parameters and electron microscopic evidence again suggested perturbations in surfactant homeostasis. Histologically, bronchiolitis and thickening of the central acinar regions was seen at 10 and 4 mg m,3, reflecting changes in cell proliferation in the terminal bronchioles and centro-acinar regions. Almost all effects seen had recovered by day 30 post-exposure. Both acute and subacute studies demonstrate rapid recovery of effects in the lung following exposure to PMDI, with no progression of these effects even at concentrations higher than those shown to produce tumours in a chronic study. These findings add weight to the hypothesis that pulmonary tumours seen following chronic exposure to PMDI are most likely due to a combination of the chronic irritant effects of repeated exposure, coupled with the presence of insoluble polyureas formed by polymerization of PMDI (found in studies reported here and previous chronic studies), and therefore acute or short-term exposures to PMDI are likely to be of little concern for long-term pulmonary health. Copyright © 2002 John Wiley & Sons, Ltd. [source] Managing precipitation use in sustainable dryland agroecosystemsANNALS OF APPLIED BIOLOGY, Issue 2 2004GARY A PETERSON Summary In the Great Plains of North America potential evaporation exceeds precipitation during most months of the year. About 75% of the annual precipitation is received from April through September, and is accompanied by high temperatures and low relative humidity. Dryland agriculture in the Great Plains has depended on wheat production in a wheat-fallow agroecosystem (one crop year followed by a fallow year). Historically this system has used mechanical weed control practices during the fallow period, which leaves essentially no crop residue cover for protection against soil erosion and greatly accelerates soil organic carbon oxidation. This paper reviews the progress made in precipitation management in the North American Great Plains and synthesises data from an existing long-term experiment to demonstrate the management principles involved. The long-term experiment was established in 1985 to identify dryland crop and soil management systems that would maximize precipitation use efficiency (maximization of biomass production per unit of precipitation received), improve soil productivity, and increase economic return to the farmers in the West Central portion of the Great Plains. Embedded within the primary objective are sub-objectives that focus on reducing the amount of summer fallow time and reversing the soil degradation that has occurred in the wheat-fallow cropping system. The experiment consists of four variables: 1) Climate regime; 2) Soils; 3) Management systems; and 4) Time. The climate variable is based on three levels of potential evapotranspiration (ET), which are represented by three sites in eastern Colorado. All sites have annual long-term precipitation averages of approximately 400,450 mm, but vary in growing season open pan evaporation from 1600 mm in the north to 1975 mm in the south. The soil variable is represented by a catenary sequence of soils at each site. Management systems, the third variable, differ in the amount of summer fallow time and emphasize increased crop diversity. All systems are managed with no-till techniques. The fourth variable is time, and the results presented in this paper are for the first 12 yr (3 cycles of the 4-yr system). Comparing yields of cropping systems that differ in cycle length and systems that contain fallow periods, when no crop is produced, is done with a technique called "annualisation". Yields are "annualised" by summing yields for all crops in the system and dividing by the total number of years in the system cycle. For example in a wheat-fallow system the wheat yield is divided by two because it takes 2 yr to produce one crop. Cropping system intensification increased annualised grain and crop residue yields by 75 to 100% compared to wheat-fallow. Net return to farmers increased by 25% to 45% compared to wheat-fallow. Intensified cropping systems increased soil organic C content by 875 and 1400 kg ha,1, respectively, after 12 yr compared to the wheat-fallow system. All cropping system effects were independent of climate and soil gradients, meaning that the potential for C sequestration exists in all combinations of climates and soils. Soil C gains were directly correlated to the amount of crop residue C returned to the soil. Improved macroaggregation was also associated with increases in the C content of the aggregates. Soil bulk density was reduced by 0.01g cm,3 for each 1000 kg ha,1 of residue addition over the 12-yr period, and each 1000 kg ha,1 of residue addition increased effective porosity by 0.3%. No-till practices have made it possible to increase cropping intensification beyond the traditional wheat-fallow system and in turn water-use efficiency has increased by 30% in West Central Great Plains agroecosystems. Cropping intensification has also provided positive feedbacks to soil productivity via the increased amounts of crop residue being returned to the soil. [source] | ||||||||||||||||||||||