A difluorodienophile, synthesised using a Stille coupling reaction underwent tin(iv)-catalysed cycloaddition with three furans to afford oxa[2.2.1]bicycloheptenes in good yield.
View Article and Find Full Text PDFThis field-based study examined the action of reinvesting in controlled processing on 14 university soccer players to assess skill breakdown under pressure. Based on scores on the Reinvestment Scale of Masters, Polman, and Hammond, two experimental groups of participants were inferred to be dispositionally High or Low in Reinvestment. They performed a wall-volley soccer task, which involved kicking a ball repeatedly against a wall target zone for 90 sec.
View Article and Find Full Text PDFIn general, inter-protein electron transfer proceeds via the formation of transient complexes. The initial stage of the interaction between plastocyanin (PCu) and cytochrome f (cyt f ) from plants is mediated by complementary electrostatics. Given the diffuse nature of its acidic patch, parsley PCu is an atypical example of a plant PCu.
View Article and Find Full Text PDFPlastocyanin and cytochrome c(6) function as electron shuttles between cytochrome f and photosystem I in the photosynthetic redox chain. To transfer electrons the partners form transient complexes, which are remarkably short-lived (milliseconds or less). Recent nuclear magnetic resonance studies have revealed details of the molecular interfaces found in such complexes.
View Article and Find Full Text PDFAgricultural contaminants may be contributing to worldwide amphibian declines, but little is known about which agrichemicals pose the greatest threat to particular species. One reason for this is that tests of multiple contaminants under ecologically relevant conditions are rarely conducted concurrently. In this study, we examined the effects of 37-d exposure to the agrichemicals atrazine (4, 40, and 400 micrograms/L), carbaryl (0.
View Article and Find Full Text PDFNumerous investigations have indicated that antenatal corticosteroid administration reduces neonatal morbidity in preterm infants. Despite this, antenatal corticosteroid usage continued to be low on both sides of the Atlantic up to the late 1980s and early 1990s. Antenatal corticosteroid therapy finally came of age in 1995 with the publication of the National Institutes of Health Consensus Statement on effects of corticosteroids for fetal maturation on perinatal outcomes.
View Article and Find Full Text PDFWe describe a case of acute liver failure and death associated with the use of a preparation containing the "natural" anxiolytic kava (Piper methysticum) and passionflower (Passiflora incarnata). The patient died after a report by the Therapeutic Goods Administration (TGA) warning of the potential for hepatotoxicity associated with the use of kava-containing products. The general public and alternative medicine practitioners need to be aware of the potential for non-prescription drugs to cause serious hepatic reactions.
View Article and Find Full Text PDFWe report two cases of primary thymic adenocarcinoma, a very uncommon neoplasm with limited information in the literature. Both patients were men (age 15 and 39 years). The first case was a mucinous carcinoma, a subtype of adenocarcinoma not previously recognized in the thymus.
View Article and Find Full Text PDFTransient complex formation between plastocyanin from Prochlorothrix hollandica and cytochrome f from Phormidium laminosum was investigated using nuclear magnetic resonance (NMR) spectroscopy. Binding curves derived from NMR titrations at 10 mM ionic strength reveal a 1:1 stoichiometry and a binding constant of 6 (+/-2) x 10(3) M(-1) for complex formation, 1 order of magnitude larger than that for the physiological plastocyanin-cytochrome f complex from Ph. laminosum.
View Article and Find Full Text PDFPatient and user involvement is central to current government thinking on the NHS. More comprehensive approaches to organised community participation and community development have received less support and examples of effective and genuine participation in key areas such as primary care decision-making are rare. The initiative described in this paper was established in Newcastle upon Tyne in 1995 to promote community participation in decision-making about local health services.
View Article and Find Full Text PDFPhenylsulfenyl chloride reacts with racemic endo Diels-Alder adduct 4 (DEC = CONEt(2)) to afford lactone 8, which can be reduced and protected in a series of high-yielding steps. Key sulfone 10 can be ring opened under strong base conditions to afford vinyl sulfone 11. Attempted desulfonation resulted in the formation of a monofluoroalkene, but a direct desulfonation/eliminative ring opening with strain relief delivered highly functionalized monocyclic species 16.
View Article and Find Full Text PDFDuring oxygenic photosynthesis, cytochrome c(6) shuttles electrons between the membrane-bound complexes cytochrome bf and photosystem I. Complex formation between Phormidium laminosum cytochrome f and cytochrome c(6) from both Anabaena sp. PCC 7119 and Synechococcus elongatus has been investigated by nuclear magnetic resonance spectroscopy.
View Article and Find Full Text PDFThe complex of yeast cytochrome c and cytochrome f from the cyanobacterium Phormidium laminosum was investigated by NMR spectroscopy. Chemical shift perturbation analysis reveals that residues around the haem edge of cytochrome c are involved in the complex interface. Binding curves derived from an NMR spectroscopy titration at 10 mM ionic strength indicate that there are two sites for cytochrome c with binding constants of approximately 2 x 10(4) M(-1) and 4 x 10(3) M(-1).
View Article and Find Full Text PDFThe transient complex of bovine myoglobin and cytochrome b(5) has been investigated using a combination of NMR chemical shift mapping, (15)N relaxation data, and protein docking simulations. Chemical shift perturbations observed for cytochrome b(5) amide resonances upon complex formation with either metmyoglobin (Fe(III)) or carbon monoxide-bound myoglobin (Fe(II)) are more than 10-fold smaller than in other transient redox protein complexes. From (15)N relaxation experiments, an increase in the overall correlation time of cytochrome b(5) in the presence of myoglobin is observed, confirming that complex formation is occurring.
View Article and Find Full Text PDFThe effect of human placental lactogen (hPL), a member of the somatomammotrophin family, on the regulation of the scavenger receptor molecules CD14 and CD163 on human monocytes cultured for 48h was investigated. Cells were cultured in the presence or absence of the hormone and also in the presence or absence of IFN-gamma and dexamethasone. Monocytes cultured in the presence of hPL showed a significant increase in the expression of CD14 in both males and females compared to background.
View Article and Find Full Text PDFOptimizing absorption can present unique demands in many animal studies because where dose-response linearity and high tissue exposure levels are required, doses may be greater than when administered for therapeutic effect. At the same time, investigative molecular constructs designed to enhance potency and specificity can have features that militate against efficient absorption. Pre-treatment or formulation to optimize absorption may be warranted.
View Article and Find Full Text PDFThe complex of the photosynthetic redox partners plastocyanin and cytochrome f from the thermophilic cyanobacterium, Phormidium laminosum, was investigated by nuclear magnetic resonance (NMR). Chemical-shift perturbation analysis of amide proton and nitrogen nuclei implicates the hydrophobic patch and, to a lesser extent, the "eastern face" of plastocyanin in the complex interface. Intermolecular pseudocontact shifts observed in the complex of cadmium-substituted plastocyanin and ferric cytochrome f specifically define the site of interaction to be between the hydrophobic patch of plastocyanin and the heme region of cytochrome f.
View Article and Find Full Text PDF6-Acetoxycyclohexa-2,4-dienones are found to undergo a rapid reaction in methanol/water under mildly basic conditions to give an acyclic ketoester as the major product for 6-phenyl and 6-methyl substrates. Reaction monitoring by UV spectroscopy indicates the formation of an unsaturated ketone reaction intermediate (lambda(max) 275 nm, R = Ph) and the transient appearance of a highly conjugated species. Reaction of the 6-phenyl substrate (4.
View Article and Find Full Text PDFAn essential protein translocation pathway in Escherichia coli and Bacillus subtilis involves the signal recognition particle (SRP), of which the 54-kDa homolog (Ffh) is an essential component. In a previous study, we found that a transposon insertion in the ylxM-ffh intergenic region of the designated secretion and acid tolerance (sat) operon of Streptococcus mutans resulted in an acid-sensitive phenotype. In the present study, we further characterized this genomic region in S.
View Article and Find Full Text PDFJ Clin Psychopharmacol
October 2000
In this study, open-label valproate (VPA) was administered to patients as a treatment for periodic limb movement disorder (PLMD). Six patients aged 28 to 62 years with complaints of sleep disturbance and at least five periodic limb movements (PLMs) per hour of sleep underwent polysomnograms (PSGs) with and without low-dose VPA treatment (125-600 mg at bedtime). After a baseline PSG, patients received VPA therapy from 2 weeks to 14 months, until the time of the follow-up PSG on VPA (median, 5 months; mean, 6 months).
View Article and Find Full Text PDFThe hawk-dove game has proved to be an important tool for understanding the role of aggression in social interactions. Here, the game is presented in a more general form (GHD) to facilitate analyses of interactions between individuals that may differ in "size", where size is interpreted as a surrogate for resource holding power. Three different situations are considered, based on the availability and use of information that interacting individuals have about their sizes: the classical symmetric case, in which no information about sizes is used, the asymmetric case, in which the individuals know their relative sizes and thus their chances of prevailing in combat, and a mixed-symmetry case, in which each individual only knows its own size (or only knows its opponent's size).
View Article and Find Full Text PDFCalibration of a lung counter requires the use of a realistic torso phantom. The depth profile of both torso phantoms' (LLNL and JAERI) chest plate covers is fixed and assumed to be equivalent to a person's chest wall; however, ultrasound measurements of humans have shown this to be an approximation. When the depth profile of a calibration phantom is different from that of a subject, then a systematic uncertainty will be introduced into the activity estimate.
View Article and Find Full Text PDF