Search

A series of new cationic palladium(II) complexes were prepared and studied for their ability to catalyze the Wacker-type oxidation of styrenes to their corresponding acetophenones using O2 as the sole oxidant. Catalysts are active at room temperature and the study highlights the importance of solvent choice and the need for ligand development in improving catalyst performance. [ABSTRACT FROM AUTHOR]

2-Ynamides can be synthesised through PdII catalysed oxidative carbonylation, utilising low catalyst loadings. A variety of alkynes and amines can be used to afford 2-ynamides in high yields, whilst overcoming the drawbacks associated with previous oxidative methods, which rely on dangerous solvents and gas mixtures. The use of [NBu4]I allows the utilisation of the industrially recommended solvent ethyl acetate. O2 can be used as the terminal oxidant, and the catalyst can operate under safer conditions with low O2 concentrations. [ABSTRACT FROM AUTHOR]

A homogeneous PdII catalyst, utilizing a simple and inexpensive amine ligand (TMEDA), allows 2-alkynoates to be prepared in high yields by an oxidative carbonylation of terminal alkynes and alcohols. The catalyst system overcomes many of the limitations of previous palladium carbonylation catalysts. It has an increased substrate scope, avoids large excesses of alcohol substrate and uses a desirable solvent. The catalyst employs oxygen as the terminal oxidant and can be operated under safer gas mixtures. [ABSTRACT FROM AUTHOR]

The ability to use low-frequency microwave sensing techniques to see through optically opaque objects is of great interest. One potential solution to the problem of seeing inside buildings and facilities is the use of low-frequency synthetic aperture radar. This provides the advantage of remote sensing and greater coverage than existing through-wall observation techniques. The Bright Sapphire II instrument is a low-frequency wideband quad polar synthetic aperture radar and offers such measurement capability. The first results of airborne trials are presented. [ABSTRACT FROM AUTHOR]

Background Little is known regarding patient characteristics that influence the speed of reflux oesophagitis ( RO) healing. Aim To investigate patient characteristics that may influence RO healing rates. Methods A post hoc analysis of clinical trial data for potent acid suppression treatment of RO (esomeprazole or AZD0865) was conducted. Group A underwent endoscopy at baseline, week 2 and 4, and group B at baseline, week 4 and 8. Group A patients were sub-grouped as 'rapid' (healed at 2 weeks) or unhealed at 2 weeks. Group B patients were sub-grouped as 'slow' (healed at 8 weeks, not at 4 weeks) or 'refractory' (not healed at 8 weeks). Logistic regression analysis was performed only for comparisons within group A. Results At 2, 4 and 8 weeks, RO had healed in 68%, 65% and 61% of patients unhealed at previous endoscopy, respectively. Low-grade [vs. high-grade (C or D)] RO was the only independent predictor of rapid healing in group A after logistic regression analysis. Significantly more rapid healers had low grade RO (A or B) at baseline than patients with refractory RO (84% vs. 49%; P < 0.001), and significantly more refractory patients had frequent regurgitation at baseline than slow healers (80% vs. 63%; P = 0.039). Conclusions Low- (vs. high-) grade RO determines the most rapid benefit from acid suppression. Roughly two-thirds of patients healed with each time increment of potent acid suppression therapy. This suggests that some unhealed patients may still heal with continued therapy and that truly refractory RO is rare. (ClinicalTrials.gov: NCT00206245). [ABSTRACT FROM AUTHOR]

Background and Purpose Hypoxia in tumours is known to cause resistance to conventional chemotherapeutic drugs. In contrast, little is known about the effects of hypoxia on targeted anti-cancer drugs. This study evaluated the effect of hypoxia on a series of clinically approved tyrosine kinase inhibitors ( TKIs). Experimental Approach The effect of hypoxia (0.1% oxygen) on the activity of conventional cytotoxic drugs (5-fluorouracil, doxorubicin and vinblastine), the hypoxia-activated prodrug tirapazamine and 9 TKIs was determined in a panel of cell lines. Where hypoxia had a marked effect on chemosensitivity, Western blot analysis was conducted to determine the effect of hypoxia on target expression and the effect of TKIs on cell signalling response under aerobic and hypoxic conditions. Key Results Three patterns of chemosensitivity were observed: resistance under hypoxia, equitoxic activity against hypoxic and aerobic cells, and preferential cytotoxicity to hypoxic cells. Significant hypoxia selectivity (independent of HIF1) was observed in the case of dasatinib and this correlated with the ability of dasatinib to inhibit phosphorylation of Src at tyrosine 530. Sorafenib was significantly less effective under hypoxic conditions but resistance did not correlate with hypoxia-induced changes in Raf/ MEK/ ERK signalling. Conclusions and Implications Hypoxia influences the activity of TKIs but in contrast to conventional cytotoxic drugs, preferential activity against hypoxic cells can occur. The search for hypoxia-targeted therapies has been long and fruitless and this study suggests that some clinically approved TKIs could preferentially target the hypoxic fraction of some tumour types. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine if the abrasive effect on dentine of two commercially available toothpastes, known to vary in their in vitro abrasive levels, can be differentiated in an in situ model after 10 days, assessed by contact profilometry. This was a single centre, single blind, randomized, split mouth, two treatment, in situ study, in 34 healthy subjects, evaluating the abrasive effects of two marketed desensitizing toothpastes, (Colgate® Sensitive Multi Protection toothpaste – C; Sensodyne® Total Protection – S). Subjects wore bi-lateral, lower buccal appliances, each fitted with four dentine sections which were power brushed three times a day with the treatment regimen. Each subject received two toothpaste treatments for 10 days during the treatment period. Samples were measured at baseline and day 10 by contact and non-contact profilometry and day 5 by contact profilometry. Thirty-four subjects were included in the efficacy analysis. Results from contact profilometry showed statistically significant ( P < 0·0001) dentine loss compared to baseline at day 5 and 10 for both pastes. At each time point, C showed statistically significantly greater dentine loss than S, P < 0·0001. After 10 days treatment, the difference in dentine loss between the pastes was 1·4 μm. The non-contact profilometry data showed similar trends. After 10 days of treatment, C showed statistically significantly greater dentine loss than S, with treatment difference of 0·9 μm, P = 0·0057. The methodology used has successfully differentiated between the abrasivity of the two pastes in respect of dentine surface loss over time in an in situ environment. [ABSTRACT FROM AUTHOR]

Information on the Autumn Meeting, "Cartilage metabolism and cell based therapies for tissue regeneration" of the British Society for Matrix Biology which was held on September 8-9, 2008 at the School of Biosciences, Cardiff University in Great Britain is presented. The meeting focused on matrix metabolism and tissue engineering strategies for cartilage repair, which was presented by Professor Tim Hardingham.

We used three-dimensional video analysis of feeding experiments to determine the effects of water depth on prey detection and capture by drift-feeding juvenile coho salmon ( Oncorhynchus kisutch) and steelhead ( O. mykiss irideus). Depth treatments were 0.15, 0.30, 0.45 and 0.60 m. Mean prey capture probabilities for both species were constant across all treatments (coho = 0.51, steelhead = 0.39), and did not differ significantly between species. In deeper treatments, capture probabilities were lower nearer the surface than they were nearer the substrate, particularly at the lateral edges of the foraging area. In deeper treatments coho had greater capture probabilities nearer the surface than did steelhead. It is unclear if this was a species difference, or one based on the relative amount of foraging experience the fish had in the wild prior to capture. Prey capture manoeuver characteristics were very similar for both species, including positive relationships between water depth and both prey detection distance and prey interception swimming speed, and no relationship between depth and speed of return to the focal point. Because prey encounter rate is expected to increase with increasing water depth, we used capture probabilities to predict capture rates for coho and steelhead, which increased linearly with water depth. We conclude that any benefit of foraging in deeper water is more likely due to increased encounter rate rather than to increased capture probability. [ABSTRACT FROM AUTHOR]

• High-light leaves of the evergreen herb Galax urceolata exhibit a striking color change from green to red during winter months due to anthocyanin synthesis in outermost mesophyll cells. Here we investigate three possible functions of this color change. • To test the hypothesis that anthocyanins function as light attenuators, maximum photosystem II efficiency ( Fv /Fm) of red and green leaves was measured during and after exposure to wavelengths either strongly or poorly absorbed by anthocyanin. To determine whether anthocyanins elevate radical-scavenging capacity, antioxidant activity of red and green leaves was assessed using the α,α-diphenyl-β-picrylhydrazyl assay. Nonstructural carbohydrate levels were analyzed to test the hypothesis that anthocyanins function as a carbon sink. • Declines in Fv /Fm under white and green light were significantly greater for green than red leaves, but were comparable under red light. Anthocyanin content positively correlated with antioxidant activity. Although levels of anthocyanins did not appear to be related to nonstructural carbohydrate concentration, high levels of sugars may be necessary for their photoinduction. • Results suggest that anthocyanins function as light attenuators and may also contribute to the antioxidant pool in winter leaves. [ABSTRACT FROM AUTHOR]

Two open-label, randomized, 2-way crossover studies (1 single-dose and 1 steady-state) were conducted in healthy volunteers to compare the pharmacokinetics and pharmacodynamics of a novel extended-release ciprofloxacin (ciprofloxacin ER; 500 mg once daily) and immediate-release ciprofloxacin (ciprofloxacin IR; 250 mg twice daily). For both studies, mean ciprofloxacin maximum concentration (Cmax) values after once-daily ciprofloxacin ER were significantly greater than those after the first daily dose of ciprofloxacin IR (P < .0001) but were lower than those after the second daily dose of ciprofloxacin IR (P < .05). The relative bioavailability of ciprofloxacin ER compared to ciprofloxacin IR was 93.8% in the single-dose study and 97.7% in the steady-state study. Mean urinary ciprofloxacin concentrations and excretion rates after either treatment were substantially greater than the minimum inhibitory concentrations (MICs) for susceptible uropathogens in both studies. The area under the concentration-time curve (AUC)/MIC, Cmax/MIC, amount excreted (Ae)/MIC, and Ae24/MIC ratios with ciprofloxacin ER were similar to or slightly greater than with ciprofloxacin IR for all susceptible organisms. [ABSTRACT FROM AUTHOR]

Reports on a study which investigated the premedication of eutectic mixture of local anesthetics (EMLA) in children. Recommendation of the manufacturer of EMLA; Assesment of its efficacy.

Food refusal can be a source of conflict between dying people and their caregivers. This review examines: the nature and purpose of food; some reasons for and implications of anorexia in terminal illness; ethical principles underpinning responses to declining appetite and food refusal; social transactions between dying people and their caregivers in relation to needs and wishes for food; and the need for further empirical research. The nature and purpose of food in human societies has been studied extensively by anthropologists but the knowledge gained is not often imported into health care practice, where eating is seen from a medical rather than an anthropological perspective. Food refusal may be a consequence of anorexia which is the result of physiological or psychological changes or it may be a deliberate choice in acceptance of impending death. Ethical principles underpinning responses to declining appetite and food refusal have been studied extensively and clear guidance obtained about what would be appropriate behaviour in given circumstances. There is little published empirical work on social transactions between dying people and their caregivers in relation to needs and wishes for food. As the contribution made to effective care-giving by high-quality interpersonal relationships is widely recognized, further knowledge about how best to sustain such relationships in these important circumstances would be useful. Moreover, as such interpersonal relationships often occur in an institutional context, it may be that more can be learnt from close examination of social transactions about how best to structure organizational processes to maximize autonomy and comfort for patients at the end of life. Further research is indicated. [ABSTRACT FROM AUTHOR]

In some patients with accessory pathways preexcitation occurs intermittently during sinus rhythm. In these patients the antegrade refractory period of the accessory pathway may either exceed the sinus cycle length under some circumstances, or conduction block in the accessory pathway may be variable. The ability of intravenous adenosine to unmask intermittent preexcitation was determined in patients with intermittent preexcitation but absent preexcitation at the time of study. Six patients undergoing assessment of the Wolff-Parkinson-White syndrome received incremental doses of intravenous adenosine (3, 6, and 12 mg). Adenosine administration was repeated in three patients after intravenous β blockade (propranolol 0.2 mg/kg). Adenosine unmasked preexcitation in all patients. P delta intervals with preexcited beats were substantially shorter than resting PR intervals in all cases (range 40-80 msec shorter). In 4/6 patients preexcitation was seen early, coincident with the onset of atrioventricular nodal block. In 4/6 patients preexcitation was seen late during the secondary sinus tachycardia that follows the direct cardiac effects of adenosine. Two patients exhibited early preexcitation and late preexcitation. Beta blockade failed to prevent early preexcitation (2/2 patients) but abolished preexcitation related to sinus tachycardia (3/3 patients). Early preexcitation, coincident with the onset of AV nodal block, suggests a direct effect of adenosine on accessory pathway conduction. Late preexcitation, occurring during secondary sinus tachycardia, and abolished by β blockade, suggests enhanced accessory pathway conduction due to sympathetic activation. [ABSTRACT FROM AUTHOR]

A cold stage for Bragg-Brentano geometry X-ray powder diffraction is described for use in the temperature range from about 250 to 300 K. The stage is constructed in such a way that it may be removed from the diffractometer and pre-cooled to its base temperature before the sample is loaded. After loading, thermoelectric cooling maintains the specimen at low temperature (ice free) whilst the body of the stage is allowed to return to room temperature prior to remounting on the diffractometer. [ABSTRACT FROM AUTHOR]

Reports on the case of difficulty with diagnosis of a right atrial mass in a patient who was referred to cardiothoraic unit for urgent resection of a right atrial myxoma. Presence of systolic cardiac murmur radiating to the carotids and bilateral biting edema at the ankles; Use of bicaval venous bypass line to facilitate a right atrial incision in the surgical plan; Induction of general anesthesia.

The improved protocol uses a novel catalyst system and has a wider substrate scope than previous methods. [ABSTRACT FROM AUTHOR]

Presents a letter and reply on various connections within breathing systems. Inappropriate connection of the expiratory limb of a breathing circuit to a patient safety valve of the Scandia absorber circuit block; Need for training of clinical staff on the equipment they are using.

A response from the authors of the article "Editorial: healing of refractory reflux oesophagitis - an ongoing unmet clinical need" in the previous issue is presented.

Focuses on dosage-related bupivacaine treatment for analgesia to the recurrence of Horner's syndrome in women after labor. Results in administering bupivacaine with different dosage to a patient with Horner's syndrome; Effects of 'mobile' epidural with reduced bupivacaine dose; Advantages of 'mobile' epidural approach.

The SOX2 anophthalmia syndrome is emerging as a clinically recognizable disorder that has been identified in 10-15% of individuals with bilateral anophthalmia. Extra-ocular anomalies are common. The majority of SOX2 mutations identified appear to arise de novo in probands ascertained through the presence of anophthalmia or microphthalmia. In this report, we describe two sisters with bilateral anophthalmia/microphthalmia, brain anomalies and a novel heterozygous SOX2 gene single-base pair nucleotide deletion, c.551delC, which predicts p.Pro184ArgfsX19. The hypothetical protein product is predicted to lead to haploinsufficient SOX2 function. Mosaicism for this mutation in the SOX2 gene was also identified in their clinically unaffected mother in peripheral blood DNA. Thus it cannot be assumed that all SOX2 mutations in individuals with anophthalmia/microphthalmia are de novo. Testing of parents is indicated when a SOX2 mutation is identified in a proband., (Copyright 2008 Wiley-Liss, Inc.)