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Situ Production (situ + production)
Selected AbstractsStereoselective Synthesis of Various ,-Selenoglycosides Using in situ Production of ,-Selenolate Anion.CHEMINFORM, Issue 21 2007Masahiro Nanami Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Novel natural parabens produced by a Microbulbifer bacterium in its calcareous sponge host Leuconia niveaENVIRONMENTAL MICROBIOLOGY, Issue 6 2009Elodie Quévrain Summary A broad variety of natural parabens, including four novel structures and known ethyl and butyl parabens, were obtained from culture of a Microbulbifer sp. bacterial strain isolated from the temperate calcareous marine sponge Leuconia nivea (Grant 1826). Their structures were elucidated from spectral analysis, including mass spectrometry and 1D and 2D nuclear magnetic resonance. Their antimicrobial activity evaluated against Staphylococcus aureus was characterized by much higher in vitro activity of these natural paraben compounds 3,9 than commercial synthetic methyl and propyl parabens, usually used as antimicrobial preservatives. Compounds 4 and 9 revealed a bacteriostatic effect and compounds 6 and 7 appeared as bactericidal compounds. Major paraben compound 6 was also active against Gram positive Bacillus sp. and Planococcus sp. sponge isolates and was detected in whole sponge extracts during all seasons, showing its persistent in situ production within the sponge. Moreover, Microbulbifer sp. bacteria were visualized in the sponge body wall using fluorescence in situ hybridization with a probe specific to L4-n2 phylotypes. Co-detection in the sponge host of both paraben metabolites and Microbulbifer sp. L4-n2 indicates, for the first time, production of natural parabens in a sponge host, which may have an ecological role as chemical mediators. [source] Predicting the effects of marine climate change on the invertebrate prey of the birds of rocky shoresIBIS, Issue 2004Michael A. Kendall By the end of the 21st century models of climate change predict that the air temperature over most of the British Isles will increase by between 2 and 3 °C and sea-level will rise by 40,50 cm. Over that period it will become windier and mean wave height will increase, as will the frequency of storms. These changes in climate and weather will impact the intertidal zone of the UK and will cause distribution changes in many of the common invertebrate species that live there. Where these changes are severe they may well impact on patterns of distribution of ducks and wading birds. In the British Isles a number of organisms live close to their geographical limits of distribution. Some of these species might be expected to extend their range as climatic restraints are relaxed. Species currently limited by cool summers or winter cold will move northwards. In most cases the effects on the distribution of waterbirds will be small. For example, the replacement of the Northern Limpet Patella vulgata by the Southern Limpet P. depressa is unlikely to adversely affect Eurasian Oystercatchers Haematopus ostralegus. Of wider concern is the possibility that as climate warms the abundance and productivity of brown algae will decrease. This is likely to have two significant effects for waders. First, it would represent a loss of potentially rich feeding grounds for species such as Ruddy Turnstone Arenaria interpres that feed on small easily desiccated invertebrates living on or below the seaweed. Secondly, as algae die or are broken away the resulting debris is exported to sediment habitats where it considerably boosts the in situ production of bacteria at the base of the food web. An increase in sea-level will only have a major impact on the extent of rocky shore invertebrate communities where shore topography prevents the upward migration of the biota. Where a seawall limits shores, for example, biological production will be curtailed as the area available for colonization decreases. Increases in the size of waves and the frequency of storms will mimic increasing exposure and there will be a significant reduction in algal production in areas that are affected. [source] The 8-epimer of prostaglandin F2,, a marker of lipid peroxidation and oxidative stress, is decreased in the nipple aspirate fluid of women with breast cancerINTERNATIONAL JOURNAL OF CANCER, Issue 9 2007Ferdinando Mannello Abstract Breast cancer (BC), a worldwide disease with increasing incidence, develops from ductal/lobular epithelium. Nipple aspirate fluid (NAF), secreted from the breast ducts and lobules, can be analyzed to assess breast metabolic activity. Whether lipid peroxidation in the mammary gland promotes or prevents tumorigenesis is unclear. Malondialdehyde (MDA) and the 8-epimer of Prostaglandin F2, (8-iso-PGF2,), two lipid peroxidation markers, were studied in milk (n = 10), NAF (n = 140) and plasma (n = 35) samples. MDA was detected in all plasma, in 80% of milk samples and in 95% of NAF samples. MDA levels in NAF and plasma were significantly higher than in milk (p = 0.016 and p = 0.029, respectively). We found no significant difference between levels of MDA in NAF samples from BC patients compared to healthy controls. 8-iso-PGF2, was detectable in all samples. 8-iso-PGF2, median levels in NAF were significantly higher than in both milk and plasma (p < 0.0001). The highest 8-iso-PGF2, levels were found in NAF from healthy women, significantly higher than in women with BC (p < 0.0001). No significant differences were found in both markers after the age-adjustment. High levels of lipid peroxidation products in NAF suggest their in situ production in the nonlactating breast. Active lipid peroxidation may have a physiologic role in the normal mammary gland. Lower levels of 8-iso-PGF2, in NAF from BC patients suggest altered production of arachidonic acid metabolites during breast carcinogenesis. © 2006 Wiley-Liss, Inc. [source] Pronounced Catalytic Effect of a Micellar Solution of Sodium Dodecyl Sulfate (SDS) on the Efficient C-S Bond Formation via an Odorless Thia-Michael Addition Reaction through the in situ Generation of S -Alkylisothiouronium SaltsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 5 2009Habib Firouzabadi Abstract A pronounced catalytic effect of sodium dodecyl sulfate (SDS) was observed on the in situ production of S -alkylisothiouronium salts via the reaction of primary, allyl and benzyl halides with thiourea in SDS droplets .Hydrolysis of the generated S -alkylisothiouronium salts in the palisade layer of the droplets produces the corresponding thiol moieties which are immediately added to the electron-deficient olefins that are present in the micellar core to produce the thia-Michael adducts. The entire route is an almost odorless process. The yields of the products are good to excellent and the method is applicable to large-scale operation without any problem. [source] Role of lipopeptides produced by Bacillus subtilis GA1 in the reduction of grey mould disease caused by Botrytis cinerea on appleJOURNAL OF APPLIED MICROBIOLOGY, Issue 5 2004Y. Touré Abstract Aim:, Test of Bacillus subtilis strain GA1 for its potential to control grey mould disease of apple caused by Botrytis cinerea. Methods and Results:, GA1 was first tested for its ability to antagonize in vitro the growth of a wide variety of plant pathogenic fungi responsible for diseases of economical importance. The potential of strain GA1 to reduce post-harvest infection caused by B. cinerea was tested on apples by treating artificially wounded fruits with endospore suspensions. Strain GA1 was very effective at reducing disease incidence during the first 5 days following pathogen inoculation and a 80% protection level was maintained over the next 10 days. Treatment of fruits with an extract of GA1 culture supernatant also exerted a strong preventive effect on the development of grey mould. Further analysis of this extract revealed that strain GA1 produces a wide variety of antifungal lipopeptide isomers from the iturin, fengycin and surfactin families. A strong evidence for the involvement of such compounds in disease reduction arose from the recovery of fengycins from protected fruit sites colonized by bacterial cells. Conclusions:, The results presented here demonstrate that, despite unfavourable pH, B. subtilis endospores inoculated on apple pulp can readily germinate allowing significant cell populations to establish and efficient in vivo synthesis of lipopeptides which could be related to grey mould reduction. Significance and Impact of the Study:, This work enables for the first time to correlate the strong protective effect of a particular B. subtilis strain against grey mould with in situ production of fengycins in infected sites of apple fruits. [source] In Situ Polymerisation of Polyamide-6 Nanocompounds from Caprolactam and Layered SilicatesMACROMOLECULAR MATERIALS & ENGINEERING, Issue 1 2009Bernd Rothe Abstract An in situ process for the production of polyamide-6 nanocompounds is investigated as an alternative to melt compounding. During the in situ production, the layered silicates are dispersed in the monomer caprolactam before the polymerisation in a twin screw extruder, leading to an intercalation of the silicates. The production of a polyamide compound containing 0, 2 and 4 wt.-% nanoscale silicates was successful. An improvement of the elastic modulus of approximately 30,60% was reached. The figure shows the TEM micrograph of a nanocompound containing 2 wt.-% nanoclay at a magnification of 30,000×. [source] In situ estrogen production and its regulation in human breast carcinoma: From endocrinology to intracrinologyPATHOLOGY INTERNATIONAL, Issue 11 2009Hironobu Sasano The great majority of breast carcinomas arising in postmenopausal women are estrogen dependent or positive for estrogen receptor (ER) in carcinoma cells despite markedly low plasma or circulating estrogen concentrations. In these patients, biologically active estrogens are locally produced from circulating inactive steroids including adrenal androgens in an intracrine mechanism in the breast cancer tissues and confer estrogenic activities on carcinoma cells. A series of enzymes are involved in this intra-tumoral or in situ production of estrogens in breast carcinoma tissues but aromatase, a member of the cytochrome P450 family, is a key enzyme of estrogen production through conversion from circulating adrenal androgens in estrogen-dependent postmenopausal breast cancer. It then becomes important to identify the sites of this estrogen production. There has been, however, controversy regarding intra-tumoral localization of aromatase in breast carcinoma, especially whether intra-tumoral production of estrogens through aromatase occurs in carcinoma or stromal cells. The enzyme was demonstrated to be expressed in both carcinoma and stromal cells in breast carcinoma tissues on immunohistochemistry with a well-characterized mAb 677 and combined laser capture microdissection/qualitative reverse transcriptase,polymerase chain reaction. Intra-tumoral aromatase in both of these cell types was subsequently demonstrated to be induced by carcinoma,stromal interactions associated with carcinoma invasion in breast tissue. The signals through various nuclear receptors, especially estrogen-related receptor-, in carcinoma cells and liver receptor homologue-1 in adipocytes adjacent to carcinoma invasion, in conjunction with various cytokines and/or growth factors, play pivotal roles in this induction of intra-tumoral aromatase. This increased aromatase subsequently results in increased in situ estrogen concentrations of breast cancer. Aromatase inhibitors are currently established as the gold standard for the treatment for ER-positive breast carcinoma but resistance to the therapy still remains to be solved by other modes of suppression of intra-tumoral estrogen production. [source] Monitoring in Real Time with a Microelectrode the Release of Reactive Oxygen and Nitrogen Species by a Single Macrophage Stimulated by its Membrane Mechanical DepolarizationCHEMBIOCHEM, Issue 4 2006Christian Amatore Prof. Abstract Macrophages are key cells of the immune system. During phagocytosis, the macrophage engulfs a foreign bacterium, virus, or particle into a vacuole, the phagosome, wherein oxidants are produced to neutralize and decompose the threatening element. These oxidants derive from in situ production of superoxide and nitric oxide by specific enzymes. However, the chemical nature and sequence of release of these compounds is far from being completely determined. The aim of the present work was to study the fundamental mechanism of oxidant release by macrophages at the level of a single cell, in real time and quantitatively. The tip of a microelectrode was positioned at a micrometric distance from a macrophage in a culture to measure oxidative-burst release by the cell when it was submitted to physical stimulation. The ensuing release of electroactive reactive oxygen and nitrogen species was detected by amperometry and the exact nature of the compounds was characterized through comparison with in vitro electrochemical oxidation of H2O2, ONOO,, NO., and NO2, solutions. These results enabled the calculation of time variations of emission flux for each species and the reconstruction of the original flux of production of primary species, O2., and NO., by the macrophage. [source] | ||||||||||||||||