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Rapid Reduction (rapid + reduction)
Selected AbstractsRapid Reduction of Nitriles to Primary Amines with Nickel Boride at Ambient Temperature.CHEMINFORM, Issue 38 2002Jitender M. Khurana Abstract For Abstract see ChemInform Abstract in Full Text. [source] Rapid reduction of Legionella pneumophila on stainless steel with zeolite coatings containing silver and zinc ionsLETTERS IN APPLIED MICROBIOLOGY, Issue 2 2003P. Rusin Abstract Aims: To determine the rate of reduction of Legionella pneumophila by stainless steel surfaces with zeolite ceramic coatings containing 2·5% (w/w) silver (Ag) and 14% zinc (Zn) ions. Methods and Results: Stainless steel pans with and without Ag/Zn coatings were inoculated with solutions of Leg. pneumophila ATCC 33155 and incubated at 37 °C. Survival was monitored using the spread-plate technique on selective buffered charcoal yeast extract agar. Significant reductions of Leg. pneumophila were effected by the Ag/Zn zeolite coatings within 2 h of exposure. Conclusions, Significance and Impact of the Study: Zeolite ceramic Ag/Zn coatings impart significant anti- Legionella properties to stainless steel surfaces. Coated stainless steel could be used in the manufacture of air ducts, condensation pans and intake and exhaust vents. These products have the potential to reduce numbers of Legionella in air-handling systems. [source] Linkage disequilibrium in the North American Holstein populationANIMAL GENETICS, Issue 3 2009E.-S. Kim Summary Linkage disequilibrium was estimated using 7119 single nucleotide polymorphism markers across the genome and 200 animals from the North American Holstein cattle population. The analysis of maternally inherited haplotypes revealed strong linkage disequilibrium (r2 > 0.8) in genomic regions of ,50 kb or less. While linkage disequilibrium decays as a function of genomic distance, genomic regions within genes showed greater linkage disequilibrium and greater variation in linkage disequilibrium compared with intergenic regions. Identification of haplotype blocks could characterize the most common haplotypes. Although maximum haplotype block size was over 1 Mb, mean block size was 26,113 kb by various definitions, which was larger than that observed in humans (,10 kb). Effective population size of the dairy cattle population was estimated from linkage disequilibrium between single nucleotide polymorphism marker pairs in various haplotype ranges. Rapid reduction of effective population size of dairy cattle was inferred from linkage disequilibrium in recent generations. This result implies a loss of genetic diversity because of the high rate of inbreeding and high selection intensity in dairy cattle. The pattern observed in this study indicated linkage disequilibrium in the current dairy cattle population could be exploited to refine mapping resolution. Changes in effective population size during past generations imply a necessity of plans to maintain polymorphism in the Holstein population. [source] Rapid tryptophan depletion as a treatment for acute mania: a double-blind, pilot-controlled studyBIPOLAR DISORDERS, Issue 8 2007Julia Applebaum Objectives:, Rapid reduction of up to 80% in plasma tryptophan level can be accomplished by administering an oral tryptophan-free amino acid solution, which induces hepatic protein synthesis and thereby depletes available plasma tryptophan. Rapid tryptophan depletion (RTD) has been shown to induce transient depressive symptoms in patients with remitted major depression. The effect of RTD in acutely manic patients has not been studied. Methods:, We carried out a double-blind, placebo-controlled pilot study of RTD in acutely manic patients. Patients were randomized to the treatment groups. Sodium valproate treatment was started at a dose of 1000 mg/day and continued throughout the 7-day study. On days 1-7, patients received a daily tryptophan-free amino acid drink or a placebo drink. The tryptophan-free amino acid drink contained a mix of amino acids without tryptophan. The placebo drink contained the additives and constituents of the real mixture to provide identical flavor and texture without the amino acids. Ratings were administered at baseline and then repeated on days 3, 5, and 7. All ratings were carried out by an experienced rater who was blind to the group assignment of patients. Results:, A total of 23 patients entered the study and 17 completed the 7-day treatment protocol. The patients who received the amino acid drink showed greater improvement in mania ratings. The differences in Young Mania Rating Scale (YMRS) and Clinical Global Impression (GCI) scores were significant. However, the intolerance rate was high (23%) and the findings in this pilot study are based only on results from those patients who were able to tolerate the drink. Conclusions:, Rapid tryptophan depletion may have an antimanic effect. [source] Rapid reduction of hard exudates in eyes with diabetic retinopathy after intravitreal triamcinolone: data from a randomized, placebo-controlled, clinical trialACTA OPHTHALMOLOGICA, Issue 3 2009Jörgen Larsson Abstract. Purpose:, To assess the effect of triamcinolone acetonide over 3 months on hard exudates in patients with diabetic macular oedema (DMO). Methods:, Thirty-two eyes of 16 patients with DMO and hard exudates were included in a randomized, placebo-controlled trial. Treated eyes received a single-dose (4 mg) intravitreal injection of triamcinolone acetonide. Control eyes received an injection of subconjunctival saline. Results:, The overall area of hard exudates decreased significantly between the baseline and 3-month visits in treated eyes, but not in control eyes. The mean change in level of hard exudates between the two visits was , 0.75 arbitrary units (AU) (95% confidence interval [CI] , 1.32 to , 0.18) in the central plus inner circle (1500 ,m) and , 0.81 AU (95% CI , 1.49 to , 0.13) over the whole grid (3000 ,m) in treated eyes, compared with 0.31 AU (95% CI , 0.19 to 0.82) and 0.31 AU (95% CI , 0.11 to 0.74), respectively, in control eyes (p < 0.001). Mean visual acuity improved by five letters in treated but not in control eyes (p = 0.01). Conclusions:, Intravitreal triamcinolone reduces hard exudates in the short-term in eyes with DMO. [source] Changes in markers of ovarian reserve and endocrine function in young women with breast cancer undergoing adjuvant chemotherapyCANCER, Issue 9 2010Bo Yu MD Abstract BACKGROUND: Premenopausal women undergoing chemotherapy are at risk for amenorrhea and impaired fertility. The objective of the current study was to assess levels of mullerian inhibitory substance (MIS), estradiol (E2), follicle-stimulating hormone (FSH), and menstrual status, in women undergoing chemotherapy. METHODS: A nested prospective cohort study was conducted in women aged <40 years with breast cancer (BC) who were undergoing adjuvant chemotherapy (n = 26). Serum MIS, FSH, and E2 were measured before chemotherapy (baseline) and at Weeks 6, 12, 36, and 52. Controls were 134 age-matched women with known fertility. Hormone levels were compared between the cases and controls at baseline. Differences between amenorrhea and age subgroups were tested using the nonparametric Wilcoxon 2-sample test using a 2-sided , of 0.05. RESULTS: Subjects with BC and age-matched controls had similar baseline MIS levels (median, 0.94 ng/mL vs 0.86 ng/mL;, P > .05). Serum MIS decreased significantly at 6 weeks and remained suppressed for 52 weeks. E2 levels decreased, and FSH levels increased during chemotherapy; however, at 52 weeks, the levels returned to baseline. At 52 weeks, only 1 patient had MIS above the lower normal range, 15 had return of menstrual function, 11 had premenopausal levels of FSH, and 13 had follicular phase levels of E2. In women aged <35 years, 25% remained amenorrheic, whereas in women aged >35 years, 50% were amenorrheic. Amenorrheic and menstruating women were found to have similar MIS values at baseline and follow-up. CONCLUSIONS: In young women with BC, chemotherapy decreases MIS rapidly and dramatically. Rapid reductions in MIS do not appear to be predictive of subsequent menstrual function. Ovarian reserve and endocrine function may be affected differently by chemotherapy. Cancer 2010. © 2010 American Cancer Society. [source] Highways block gene flow and cause a rapid decline in genetic diversity of desert bighorn sheepECOLOGY LETTERS, Issue 10 2005Clinton W. Epps Abstract The rapid expansion of road networks has reduced connectivity among populations of flora and fauna. The resulting isolation is assumed to increase population extinction rates, in part because of the loss of genetic diversity. However, there are few cases where loss of genetic diversity has been linked directly to roads or other barriers. We analysed the effects of such barriers on connectivity and genetic diversity of 27 populations of Ovis canadensis nelsoni (desert bighorn sheep). We used partial Mantel tests, multiple linear regression and coalescent simulations to infer changes in gene flow and diversity of nuclear and mitochondrial DNA markers. Our findings link a rapid reduction in genetic diversity (up to 15%) to as few as 40 years of anthropogenic isolation. Interstate highways, canals and developed areas, where present, have apparently eliminated gene flow. These results suggest that anthropogenic barriers constitute a severe threat to the persistence of naturally fragmented populations. [source] Long-term corrosion-induced copper runoff from natural and artificial patina and its environmental impact,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2006Sofia Bertling Abstract The overall objective of this paper is to present an extensive set of data for corrosion-induced copper dispersion and its environmental interaction with solid surfaces in the near vicinity of buildings. Copper dispersion is discussed in terms of total copper flows, copper speciation and bioavailability at the immediate release situation, and its changes during transport from source to recipient. Presented results are based on extensive field exposures (eight years) at an urban site, laboratory investigations of the runoff process, published field data, generated predictive site-specific runoff rate models, and reactivity investigations toward various natural and manmade surfaces, such as those in soil, limestone, and concrete. Emphasis is placed on the interaction of copper-containing runoff water with different soil systems through long-term laboratory column investigations. The fate of copper is discussed in terms of copper retention, copper chemical speciation, breakthrough capacities, and future mobilization based on changes in copper concentrations in the percolate water, computer modeling using the Windermere Humic Aqueous Model, and sequential extractions. The results illustrate that, for scenarios where copper comes in extensive contact with solid surfaces, such as soil and limestone, a large fraction of released copper is retained already in the immediate vicinity of the building. In all, both the total copper concentration in runoff water and its bioavailable part undergo a significant and rapid reduction. [source] Environment and prednisone interactions in the treatment of recurrent airway obstruction (heaves)EQUINE VETERINARY JOURNAL, Issue 5 2000C. A. Jackson Summary Recurrent airway obstruction (RAO) or heaves is a manifestation of a hypersensitivity to dust, moulds, and spores in the environment of a susceptible horse. Although in the majority of RAO-affected horses, clinical remission can be achieved by keeping horses at pasture to reduce their allergen exposure, this often is not practicable. For this reason, we investigated if changing the environment of a single stall in a 4 stall stable was sufficient to improve lung function and reduce inflammation in RAO-affected horses. In addition, we determined if addition of oral prednisone provided additional benefit. Twelve RAO-susceptible horses were stabled, fed hay, and bedded on straw until they developed airway obstruction. At this point, bedding was changed to wood shavings and they were fed a pelleted diet for 2 weeks. Lung function was measured and bronchoalveolar lavage was performed before and 3, 7, and 14 days after environmental modification. In a crossover design, horses were treated for the 14 days with prednisone tablets (2.2 mg/kg bwt, q. 24 h). Horses then returned to pasture for 30 days. Airway obstruction was greatest before environmental modification. Significant improvement in lung function occurred within 3 days of the change in environment and continued to Day 7. Airway function was best after 30 days at pasture. The clinical response achieved by environmental modification was not significantly improved by addition of oral prednisone. The total number of cells, total neutrophils, and percent neutrophils was greatest before environmental modification. In the absence of prednisone, total and percent neutrophils did not decrease until Day 14 and total cell number until 30 days at pasture. In the presence of prednisone, total cells and total and percent neutrophils decreased by Day 3 and again at pasture. The fact that lung function can be improved within 3 days by environmental management alone emphasises the need for allergen reduction as the cornerstone of treatment of RAO. Although prednisone induced a more rapid reduction in airway inflammation, this was not associated with a more rapid improvement in airway function. [source] Quantitative assessment of WT1 gene expression after allogeneic stem cell transplantation is a useful tool for monitoring minimal residual disease in acute myeloid leukemiaEUROPEAN JOURNAL OF HAEMATOLOGY, Issue 1 2009Anna Candoni Abstract Introduction:,WT1 overexpression is described in several oncological diseases including acute myeloid leukemia (AML). Quantification of WT1 in bone marrow samples may be useful as a marker of minimal residual disease (MRD) and may predict the relapse of AML after allogeneic hematopoietic stem cell transplant (HSCT). Methods and results:, The quantitative expression of WT1 was measured in 38 AML patients (16 males and 22 females) at diagnosis, at the time of transplant and after the allogeneic HSCT (at precise time points). All cases showed high WT1 expression levels at diagnosis with a mean of 4189 (SD 3325) and a median of 3495 (range 454,13923) copies WT1/104Abl. At transplant, 25 patients (66%) were in complete cytologic remission (CcR) and 13 (34%) had refractory or relapsed AML. Bone marrow samples from patients transplanted in CcR showed significantly lower WT1 expression levels during HSCT compared with the samples from patients with a relapsed or refractory AML (P = 0.004). After HSCT, a rapid decline in WT1 expression levels was observed in all patients who attained or maintained a condition of CcR. Six of 38 patients (13%) relapsed after HSCT and all of them had an increase in WT1 expression at/or before relapse. Five of these six patients died of leukemia and one was successfully reinduced with donor lymphocyte infusion (DLI) + chemotherapy with a rapid reduction of WT1 levels. Besides, we found a complete concordance between WT1 expression levels and other disease markers (when available). Conclusions:, In our experience, there was a complete concordance between WT1 expression levels (measured by quantitative RT-PCR at precise time points) and status of AML before and after allogeneic HSCT. WT1 may be useful as a non-specific leukemia marker for monitoring MRD and as a predictor of AML clinical relapse. Based on these results, cases with increase of WT1 levels after HSCT and without graft vs. host disease may be candidate to discontinuation of immunosuppression and/or DLI therapy. [source] Polyphenylene Dendrimer-Templated In Situ Construction of Inorganic,Organic Hybrid Rice-Shaped ArchitecturesADVANCED FUNCTIONAL MATERIALS, Issue 1 2010Xiaoying Qi Abstract A novel dendrimer-templating method for the synthesis of CuO nanoparticles and the in situ construction of ordered inorganic,organic CuO,G2Td(COOH)16rice-shaped architectures (RSAs) with analogous monocrystalline structures are reported. The primary CuO nanoparticles are linked by the G2Td(COOH)16 dendrimer. This method provides a way to preserve the original properties of primary CuO nanoparticles in the ordered hybrid nanomaterials by using the 3D rigid polyphenylene dendrimer (G2Td(COOH)16) as a space isolation. The primary CuO nanoparticles with diameter of (6.3,±,0.4) nm are synthesized via four successive reaction steps starting from the rapid reduction of Cu(NO3)2 by using NaBH4 as reducer and G2Td(COOH)16 as surfactant. The obtained hybrid CuO,G2Td(COOH)16 RSA, formed in the last reaction step, possesses a crystal structure analogous to a monocrystal as observed by transmission electron microscopy(TEM). In particular, the formation process of the RSA is monitored by UV,vis, TEM, and X-ray diffraction. Small angle X-ray scattering and Fourier transform infrared spectroscopy are used to investigate the role of the dendrimer in the RSA formation process. The obtained results illuminate that Cu2+COO, coordination bonds play an indispensable role in bridging and dispersing the primary CuO nanoparticles to induce and maintain the hybrid RSA. More importantly, the RSA is retained through the Cu2+COO,coordination bonds even with HCl treatment, suggesting that the dendrimers and Cu2+ ions may form rice-shaped polymeric complexes which could template the assembly of CuO nanoparticles towards RSAs. This study highlights the feasibility and flexibility of employing the peculiar dendrimers to in-situ build up hybrid architectures which could further serve as templates, containers or nanoreactors for the synthesis of other nanomaterials. [source] Hydrothermal Syntheses of Gold Nanocrystals: From Icosahedral to Its Truncated Form,ADVANCED FUNCTIONAL MATERIALS, Issue 2 2008J. Xu Abstract We have successfully controlled the shape of gold nanocrystals through a simple and low-cost hydrothermal method based on a modified polyol process. Well-defined gold nanocrystals of icosahedral shape were synthesized in high yields by the rapid reduction of gold precursors with ethylene glycol (EG) in the presence of poly(vinyl pyrrolidone) (PVP) under hydrothermal conditions for 1 h. Truncated icosahedra (football-shaped) have been prepared for the first time by prolonging the reaction time to 4 h. Both nanocrystal shapes were obtained quantitatively. Addition of citric acid inhibits the shape-change process (from icosahedron to truncated icosahedron) by blocking oxidative etching, while addition of Fe(III) facilitates the shape-change process by enhancing oxidative etching. We propose that growth of truncated icosahedra can be induced and maintained through interplay of the following processes: generation of multiple twinned seeds, shape- and size-focusing by Ostwald ripening, and oxidative etching and preferential growth on the {100} face. [source] Analysis of supersaturation and nucleation in a moving solution droplet with flowing supercritical carbon dioxideJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 4 2005Mamata Mukhopadhyay Abstract A supercritical antisolvent (SAS) process is employed for production of solid nanoparticles from atomized droplets of dilute solution in a flowing supercritical carbon dioxide (SC CO2) stream by attaining extremely high, very rapid, and uniform supersaturation. This is facilitated by a two-way mass transfer of CO2 and solvent, to and from the droplet respectively, rendering rapid reduction in equilibrium solubility of the solid solute in the ternary solution. The present work analyses the degree of supersaturation and nucleation kinetics in a single droplet of cholesterol solution in acetone during its flight in a flowing SC CO2 stream. Both temperature and composition are assumed to be uniform within the droplet, and their variations with time are calculated by balancing the heat and mass transfer fluxes to and from the droplet. The equilibrium solubility of cholesterol with CO2 dissolution has been predicted as being directly proportional to the Partial Molar Volume Fraction (PMVF) of acetone in the binary (CO2,acetone) system. The degree of supersaturation has been simulated up to the time required to attain almost zero cholesterol solubility in the droplet for evaluating the rate of nucleation and the size of the stable critical nuclei formed. The effects of process parameters have been analysed in the pressure range of 7.1,35.0 MPa, temperature range of 313,333 K, SC CO2 flow rate of 0.1136,1.136 mol s,1, the ratio of the volumetric flow rates of CO2 -to-solution in the range of 100,1000, and the initial mole fraction of cholesterol in acetone solution in the range of 0.0025,0.010. The results confirm an extremely high and rapid increase in degree of supersaturation, very high nucleation rates and stable critical nucleus diameter of the order of a nanometre. Copyright © 2005 Society of Chemical Industry [source] Substitution-reduction: an alternative process for the [18F]N -(2-fluoroethylation) of anilinesJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 4 2004Emmanuelle Briard Abstract Substitution of a halo atom (chloro or bromo) in easily prepared N -haloacetyl-anilines with no-carrier added (NCA) cyclotron-produced [18F]fluoride ion (18F, t1/2= 109.8 min; ,+=96.9%), followed by reduction with borane,tetrahydrofuran (BH3,THF), provides an alternative route to NCA [18F]N -(2-fluoroethyl)-anilines. This two-step and one-pot process is rapid (,50 min) and moderately high yielding (,40% decay-corrected radiochemical yield (RCY) overall). In the nucleophilic substitution reaction, 18-crown-6 is preferred to Kryptofix® 222 as complexing agent for the solubilization of the counter-ion (K+), derived from an added metal salt, in acetonitrile. Weakly basic potassium bicarbonate is preferred as the added metal salt. Inclusion of a small amount of water, equating to 4,5 molar equivalents relative to 18-crown-6, base or precursor (held in equimolar ratio), is beneficial in preventing the adsorption of radioactivity onto the wall of the glass reaction vessel and for achieving high RCY in the nucleophilic substitution reaction. BH3,THF is effective for the rapid reduction of the generated [18F]N -fluoroacetyl-aniline to the [18F]N -(2-fluoroethyl)-aniline. Copyright © 2004 John Wiley & Sons, Ltd. [source] Cryoradiolytic reduction of crystalline heme proteins: analysis by UV-Vis spectroscopy and X-ray crystallographyJOURNAL OF SYNCHROTRON RADIATION, Issue 1 2007Thorsten Beitlich The X-ray crystallographic analysis of redox-active systems may be complicated by photoreduction. Although radiolytic reduction by the probing X-ray beam may be exploited to generate otherwise short-lived reaction intermediates of metalloproteins, it is generally an undesired feature. Here, the X-ray-induced reduction of the three heme proteins myoglobin, cytochrome P450cam and chloroperoxidase has been followed by on-line UV-Vis absorption spectroscopy. All three systems showed a very rapid reduction of the heme iron. In chloroperoxidase the change of the ionization state from ferric to ferrous heme is associated with a movement of the heme-coordinating water molecule. The influence of the energy of the incident X-ray photons and of the presence of scavengers on the apparent reduction rate of ferric myoglobin crystals was analyzed. [source] Impact of released Eurasian otters on a population of American mink: a test using an experimental approachOIKOS, Issue 1 2004L. Bonesi Competition is considered to be a major evolutionary driving force within assemblages of related and morphologically similar species, but it is notoriously difficult to test and quantify especially amongst species that cannot be easily manipulated in a laboratory or in the field. By exploiting a re-introduction of Eurasian otters (Lutra lutra) in the Upper Thames catchment (UK) in 1999 we performed an experiment to test whether there was evidence of competition between otters and American mink (Mustela vison). Mink and otters are semi-aquatic mustelids belonging to the same guild. Otters are expected to be the dominant competitor because they are larger and better adapted at exploiting aquatic resources. Our hypothesis was that mink declines when the density of otters increases. We measured the effect of competition at the population level, by observing whether mink distribution and densities changed in an area of 1353 km2 in association with the arrival of its putative competitor. We estimated distribution and densities by means of sign surveys and trapping. The results showed that otters were associated with a significant and rapid reduction in the densities of mink, while mink occupancy remained approximately the same in an area of 2464 km2 that was used as a control. We observed that the spatial distribution of the mink population throughout its decline was influenced by the yearly cycle of mink activities, with areas being temporarily re-colonized during the dispersal season. Mink is an invasive species in the UK threatening the survival of some native species. Our findings suggest that the re-establishment of otter populations is likely to lead to a decline of mink that may, in turn, be beneficial to native species threatened by this invasive. [source] Electrophysiological Differences of the Spontaneous Onset of Paroxysmal and Persistent Atrial FibrillationPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 3 2007STEFAN WEBER M.D. Background: Information about the spatiotemporal organization of atrial activity at the onset of atrial fibrillation (AF) is still limited. Methods: AF mapping was performed in 30 patients with AF (mean age 53 ± 9 years, 26 males) by deploying a noncontact mapping balloon in the left atrium (LA). Twenty-four patients had paroxysmal AF and six patients had persistent AF. Three types of AF episodes were analyzed: nonsustained AF (lasting , 30 seconds), sustained AF (lasting > 30 seconds, with spontaneous conversion or requiring internal cardioversion and subsequent stable sinus rhythm), and persistent AF episodes (stable sinus rhythm lasting , 1 minute after cardioversion). Results: A total of 101 spontaneous AF onset episodes were analyzed. Analysis of AF onset showed that there was a progressive shortening of the initial cycle lengths from nonsustained episodes to sustained episodes and to persistent AF episodes. There was an earlier and more rapid reduction in the cycle lengths from persistent episodes to sustained episodes and to nonsustained episodes of AF (P < 0.05 for persistent vs sustained and for sustained vs nonsustained episodes). The development of multiwavelet activity and disorganization of conduction occurred earlier in persistent and sustained episodes than in nonsustained AF episodes. LA size was greater in patients with persistent AF episodes compared with patients with sustained or nonsustained AF episodes. Conclusions: Electrophysiological events that develop at the onset of AF seem to be different in different types of AF. A more rapid degeneration into the fibrillatory activity was observed in persistent and sustained AF than in nonsustained AF episodes. [source] Feline immunodeficiency virus vectors.THE JOURNAL OF GENE MEDICINE, Issue 5 2002Gene transfer to mouse retina following intravitreal injection Abstract Background Transduction of the murine retinal pigmented epithelium (RPE) with adenovirus vectors requires technically difficult and invasive subretinal injections. This study tested the hypothesis that recombinant vectors based on feline immunodeficiency virus (FIV) could access the retina following intravitreal injection. Methods FIV vectors expressing E. coli ,-galactosidase (FIV,gal) were injected alone, or in combination with adenovirus vectors expressing eGFP, into the vitreous of normal mice and eyes evaluated for transgene expression. In further studies, the utility of FIV-mediated gene transfer to correct lysosomal storage defects in the anterior and posterior chambers of eyes was tested using recombinant FIV vectors expressing ,-glucuronidase. FIV,gluc vectors were injected into ,-glucuronidase-deficient mice, an animal model of mucopolysacharridoses type VII. Results The results of this study show that similar to adenovirus, both corneal endothelium and cells of the iris could be transduced following intravitreal injection of FIV,gal. However, in contrast to adenovirus, intravitreal injection of FIV,gal also resulted in transduction of the RPE. Immunohistochemistry following an intravitreal injection of an AdeGFP (adenovirus expressing green fluorescent protein) and FIV,gal mixture confirmed that both viruses mediated transduction of corneal endothelium and cells of the iris, while only FIV,gal transduced cells in the retina. Using the ,-glucuronidase-deficient mouse, the therapeutic efficacy of intravitreal injection of FIV,gluc (FIV expressing ,-glucuronidase) was tested. Intravitreal injection of FIV,gluc to the eyes of ,-glucuronidase-deficient mice resulted in rapid reduction (within 2,weeks) of the lysosomal storage defect within the RPE, corneal endothelium, and the non-pigmented epithelium of the ciliary process. Transgene expression and correction of the lysosomal storage defect remained for at least 12,weeks, the latest time point tested. Conclusion These studies demonstrate that intravitreal injection of FIV-based vectors can mediate efficient and lasting transduction of cells in the cornea, iris, and retina. Copyright © 2002 John Wiley & Sons, Ltd. [source] Reversal of benign prostate hyperplasia by selective occlusion of impaired venous drainage in the male reproductive system: novel mechanism, new treatmentANDROLOGIA, Issue 5 2008Y. Gat Summary The prostate is an androgen-regulated exocrine gland producing over 30% of the noncellular components of the semen and promoting optimal conditions for survival and motility of sperm in the vagina. Benign prostate hyperplasia (BPH) is the most common benign neoplasm in men. Its aetiology is not clear, and therefore, current medical treatments are directed towards the symptoms. Though testosterone is known to be the promoter of prostate cell proliferation, no causal relation between serum testosterone levels and BPH has been found. In this study, we propose a novel and tested pathophysiological mechanism for the evolution of BPH and suggest a tested and effective treatment. We found that in all BPH patients, the one-way valves in the vertically oriented internal spermatic veins are destroyed (clinically manifested as varicocele), causing elevated hydrostatic pressure, some 6-fold greater than normal, in the venous drainage of the male reproductive system. The elevated pressure propagates to all interconnected vessels leading to a unique biological phenomenon: venous blood flows retrograde from the higher pressure in the testicular venous drainage system to the low pressure in the prostatic drainage system directly to the prostate (law of communicating vessels). We have found that free testosterone levels in this blood are markedly elevated, with a concentration of some 130-fold above serum level. Consequently, the prostate is exposed to: (i) increased venous pressure that causes hypertrophy; (ii) elevated concentration of free testosterone causing hyperplasia. We have treated 28 BPH patients using a technique that restores normal pressure in the venous drainage in the male reproductive system. The back-pressure and the back-flow of blood from the testicular to the prostate drainage system were eliminated and, consequently, a rapid reduction in prostate volume and a regression of prostate symptoms took place. [source] The phenomenology of exception times: Qualitative differences between problem-focussed and solution-focussed interventionsAPPLIED COGNITIVE PSYCHOLOGY, Issue 4 2010Thomas Wehr Solution-focussed brief therapy (SFBT) is a prominent psychotherapeutic approach that deals with a positive focus and promises brief interventions. In two experiments, a solution-focussed technique was compared with a problem-focussed intervention. By means of a structured questionnaire, subjects were encouraged to think about a standard (Experiment 1) or a facultative topic (Experiment 2). Subsequently, they generated either one or five exceptions or exemplary problem episodes. Dependent variables were confident in coping with the problem, ease of retrieval, psychic comfort and several phenomenological properties of the autobiographical memory. A solution-oriented intervention increased self-confidence and established a positive mood. Exception times had a more positive tone and were generally more easily retrieved than problem episodes. The study confirms the claims of the SFBT for empowerment and rapid reduction of current suffering. Copyright © 2009 John Wiley & Sons, Ltd. [source] Relationships among non-native plants, diversity of plants and butterflies, and adequacy of spatial samplingBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 2 2005ERICA FLEISHMAN Non-native invasive species are altering ecosystems in undesirable ways, often leading to biotic homogenization and rapid reduction of evolutionary potential. However, lack of money and time hampers attempts to monitor the outcome of restoration efforts. Hence, it is useful to determine whether relatively limited sampling can provide valid inferences about biological responses to pattern-based and process-based variables that are affected by restoration actions. In the Mojave Desert, invasion of salt-cedar (Tamarix ramosissima) has altered vegetational communities and some measures of faunal diversity. We tested whether six vegetation-based predictor variables affected species richness of butterflies in the Muddy River drainage (Nevada, USA). We also explored whether similar conclusions about relationships between vegetation and butterflies could have been obtained by using data from a subset of the 85 locations included in the study. We found that the effect of non-native plants on species richness of butterflies was negligible. Availability of nectar had the greatest independent explanatory power on species richness of butterflies, followed by species richness of plants. In comparison with the full data set, subsamples including 10, 25 and 50% of sites yielded similar conclusions. Our results suggest that relatively limited data sets may allow us to draw reliable inferences for adaptive management in the context of ecological restoration and rehabilitation. © 2005 The Linnean Society of London, Biological Journal of the Linnean Society, 2005, 85, 157,166. [source] Tracing thymic output in older individualsCLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 3 2010W. A. Mitchell Summary As a result of age-associated thymic atrophy, T cell production declines with age. Some studies suggest that production undergoes an exponential decline starting at birth, while others consider the decline to be in a biphasic manner with a rapid reduction in output occurring before middle age followed by a phase in which output declines at a regular, albeit much slower, rate. Both approaches provide estimations of the time of termination of thymic output, but on the basis of limited amounts of data. We have analysed blood from more than 200 individuals between the ages of 58 and 104 years to determine changes in thymic output using signal-joint T cell receptor excision circles (sjTREC)/T cells as our measure. To reduce any potential geographical or nutritional bias we have obtained samples from five different European countries. Our results reveal that while the absolute number of T cells per microlitre of blood does not change significantly across the age range we tested, the values of sjTREC per microlitre show wide variation and reveal an age-associated decline in thymic output. In addition we show gender differences, with notably higher thymic output in females than males at each decade. More importantly, we noted a significant decline in sjTREC/T cell levels in those more than 90 years of age in both males and females. Our results provide information about the potential end-point for thymic output and suggest that sjTREC analysis may be a biomarker of effective ageing. [source] Investigation of critical inter-related factors affecting the efficacy of pulsed light for inactivating clinically relevant bacterial pathogensJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2010H.P. Farrell Abstract Aims:, To investigate critical electrical and biological factors governing the efficacy of pulsed light (PL) for the in vitro inactivation of bacteria isolated from the clinical environment. Development of this alternative PL decontamination approach is timely, as the incidence of health care,related infections remains unacceptably high. Methods and Results:, Predetermined cell numbers of clinically relevant Gram-positive and Gram-negative bacteria were inoculated separately on agar plates and were flashed with ,60 pulses of broad-spectrum light under varying operating conditions, and their inactivation measured. Significant differences in inactivation largely occurred depending on the level of the applied lamp discharge energy (range 3·2,20 J per pulse), the amount of pulsing applied (range 0,60 pulses) and the distance between light source and treatment surface (range 8,20 cm) used. Greater decontamination levels were achieved using a combination of higher lamp discharge energies, increased number of pulses and shorter distances between treatment surface and the xenon light source. Levels of microbial sensitivity also varied depending on the population type, size and age of cultures treated. Production of pigment pyocynanin and alginate slime in mucoid strains of Pseudomonas aeruginosa afforded some protection against lethal action of PL; however, this was evident only by using a combination of reduced amount of pulsing at the lower lamp discharge energies tested. A clear pattern was observed where Gram-positive bacterial pathogens were more resistant to cidal effects of PL compared to Gram negatives. While negligible photoreactivation of PL-treated bacterial strains occurred after full pulsing regimes at the different lamp discharge energies tested, some repair was evident when using a combination of reduced pulsing at the lower lamp discharge energies. Strains harbouring genes for multiple resistances to antibiotics were not significantly more resistant to PL treatments. Slight temperature rises (,4·2°C) were measured on agar surfaces after extended pulsing at higher lamp discharge energies. Presence of organic matter on treatment surface did not significantly affect PL decontamination efficacy, nor did growth of PL-treated bacteria on selective agar diminish survival compared to similarly treated bacteria inoculated and enumerated on nonselective agar plates. Conclusions:, Critical inter-related factors affecting the effective and repeatable in vitro decontamination performance of PL were identified during this study that will aid further development of this athermal process technology for applications in health care and in industry. Very rapid reductions (c. 7 log10 CFU cm,2 within ,10 pulses) occurred using discharge energy of 20 J for all tested clinically relevant bacteria under study when treated at 8 cm distance from xenon light source. While no resistant flora is expected to develop for treatment of microbial pathogens on two-dimensional surfaces, careful consideration of scale up factors such as design and operational usage of this PL technique will be required to assure operator safety. Significance and Impact of the Study:, Findings and conclusions derived from this study will enable further development and optimization of this decontamination technique in health care and in food preparation settings, and will advance the field of nonthermal processing technologies. [source] The effect of intracellular acidification on the relationship between cell volume and membrane potential in amphibian skeletal muscleTHE JOURNAL OF PHYSIOLOGY, Issue 3 2005James A. Fraser The relationship between cell volume (Vc) and membrane potential (Em) in Rana temporaria striated muscle fibres was investigated under different conditions of intracellular acidification. Confocal microscope xz -scanning monitored the changes in Vc, whilst conventional KCl and pH-sensitive microelectrodes measured Em and intracellular pH (pHi), respectively. Applications of Ringer solutions with added NH4Cl induced rapid reductions in Vc that rapidly reversed upon their withdrawal. These could be directly attributed to the related alterations in extracellular tonicity. However: (1) a slower and persistent decrease in Vc followed the NH4Cl withdrawal, leaving Vc up to 10% below its resting value; (2) similar sustained decreases in resting Vc were produced by the addition and subsequent withdrawal of extracellular solutions in which NaCl was isosmotically replaced with NH4Cl; (3) the same manoeuvres also produced a marked intracellular acidification, that depended upon the duration of the preceding exposure to NH4Cl, of up to 0.53 ± 0.10 pH units; and (4) the corresponding reductions in Vc similarly increased with this exposure time. These reductions in Vc persisted and became more rapid with Cl, deprivation, thus excluding mechanisms involving either direct or indirect actions of pHi upon Cl, -dependent membrane transport. However they were abolished by the Na+,K+ -ATPase inhibitor ouabain. The Em changes that accompanied the addition and withdrawal of NH4+ conformed to a Nernst equation modified to include realistic NH4+ permeability terms, and thus the withdrawal of NH4+ restored Em to close to control values despite a persistent change in Vc. Finally these Em changes persisted and assumed faster kinetics with Cl, deprivation. The relative changes in Vc, Em and pHi were compared to predictions from the recent model of Fraser and Huang published in 2004 that related steady-state values of Vc and Em to the mean charge valency (zx) of intracellular membrane-impermeant anions, X,i. By assuming accepted values of intracellular buffering capacity (,i), intracellular acidification was shown to produce quantitatively predictable decreases in Vc. These findings thus provide experimental evidence that titration of the anionic zx by increased intracellular [H+] causes cellular volume decrease in the presence of normal Na+,K+ - ATPase activity, with Cl, -dependent membrane fluxes only influencing the kinetics of such changes. [source] Distinct mechanisms of action of anti-CD154 in early versus late treatment of murine lupus nephritisARTHRITIS & RHEUMATISM, Issue 9 2003Sergio A. Quezada Objective Treatment with anti-CD154 antibody is known to ameliorate murine lupus nephritis when given early in the disease. The aims of this study were to identify the mechanism of this early effect, to determine whether late anti-CD154 treatment could halt established nephritis, and, if so, to examine potential mechanisms of late efficacy. Methods We studied the effects of anti-CD154 treatment on autoantibody production and immune complex deposition, renal pathology, survival, and renal cytokine and chemokine messenger RNA (mRNA) expression both in (NZB × NZW)F1 mice (BW mice) and in NZM.2410 mice. Results Early treatment with anti-CD154 produced long-term survival in BW mice, with abrogation of renal immune complex deposition for months after treatment was stopped. Late anti-CD154 treatment, started after development of nephritis, could halt disease in ,40% of mice. In some mice, proteinuria could be reversed repeatedly with sequential courses of anti-CD154 antibody. The remissions induced by late treatment with anti-CD154 occurred despite ongoing renal immune complex deposition. In preliminary studies, responding mice had rapid reductions in renal mRNA for transforming growth factor ,, interleukin-10, and tumor necrosis factor ,. Conclusion Amelioration of murine lupus by anti-CD154 therapy is mediated by distinct mechanisms in early versus late intervention. We postulate that anti-CD154 therapy prevents autoantibody production and renal immune complex deposition in the early, induction phase and limits secondary tissue damage in situ in the late, effector phase. These data demonstrate that CD40,CD154 interactions are critical for the maintenance of autoimmunity and suggest a potential role for anti-CD154 as a therapeutic agent in established human lupus. [source] | ||||||||||||||||