A photochemical precursor for carbon monoxide release in aerated aqueous media.

Interest in therapeutic applications of carbon monoxide release to physiological targets has led us to explore a photochemical strategy for such CO delivery. Here, we describe the photoactivated carbon monoxide releasing moiety (photoCORM), W(CO)(5)(TPPTS)(3-) (1), an air-stable, water-soluble tungsten(0) carbonyl complex of the trianionic ligand tris(sulphonatophenyl)phosphine. Near-UV photolysis of 1 in an aqueous buffer solution leads to the high quantum yield release of a single CO, the formation of which has been verified by three analytical methodologies. Furthermore, in aerated media, additional CO is slowly released from the W(CO)(4)(H(2)O)(TPPTS)(3-) photoproduct owing to autoxidation of the tungsten center. Thus, 1 serves as a carbon monoxide releasing moiety both in the primary photochemical reaction and in the secondary reactions of the initially formed photoproduct. The three methodologies for quantifying CO release under these physiologically relevant conditions are also described.

Flash and continuous photolysis studies of the thionitrosyl complex Cr(CH3CN)5(NS)2+ and the nitric oxide analogs: reactions of nitrogen monosulfide in solution.

Photolysis of the thionitrosyl complex Cr(CH3CN)5(NS)2+ (1) in acetonitrile solution leads to the dissociation of nitrogen monosulfide (NS). In deaerated solution, this reaction is reversible, and flash photolysis studies demonstrate that NS reacts with Cr(CH3CN)62+ according to the rate law d[1]/dt = kon[Cr(CH3CN)62+][NS] (kon = 2.3 x 108 M-1 s-1 at 298 K). The photolysis of 1 in deaerated acetonitrile with added Fe(S2CNEt2)2 leads to the transfer of NS and the formation of a species concluded to be Fe(S2CNEt2)2(NS) based on its electron paramagnetic resonance spectrum. Analogous photolysis of 1 in the presence of added NO leads to clean formation of the nitrosyl complex Cr(CH3CN)5(NO)2+ (2) presumably by NO capture of the photoproduct Cr(CH3CN)6(2+) (3). When 1 was photolyzed in aerated acetonitrile solution, the reactive species 3 was trapped, thus leading to net photochemical transformations with excitation-wavelength-dependent quantum yields of 0.3-1.0 mol/Einstein. Mass spectroscopic studies of the product solutions demonstrate the formation of S8, presumably from the decomposition of NS. The quantitative photochemical behaviors of 1 and the nitrosyl analog 2 are compared.

Brassica napus DNA markers linked to white rust resistance in Brassica juncea.

White rust, caused by Albugo candida, is an economically important disease of Brassica juncea mustard. The most efficient and cost effective way of protecting mustard plants from white rust is through genetic resistance. The development of canola quality B. juncea through interspecific crosses of B. juncea with Brassica napus has lead to the introgression of white rust resistance from B. napus into B. juncea. The objective of this study was to identify DNA markers for white rust resistance, derived from the introgressed B. napus chromosome segment, in a BC(3)F(2) population of condiment B. juncea mustard. This segregating population was phenotyped for white rust reaction and used to screen for AFLP markers associated with white rust resistance using bulked segregant analysis. Segregation data indicated that a single dominant gene controlled resistance to white rust. Eight AFLP markers linked to white rust resistance were identified, all derived from B. napus. The B. napus chromosome segment, carrying the white rust resistance gene ( Ac2V(1)), appeared to have recombined with the B. juncea DNA since recombinant individuals were identified. Comparative mapping of the eight B. napus-derived AFLP markers in a typical B. napus mapping population was inconclusive; therefore, the size of the introgressed B. napus fragment could not be determined.

A multicentre comparison of piroxicam and indomethacin in acute soft tissue sports injuries.

One hundred and five patients suffering from sport-associated soft tissue injuries were included in a randomized controlled trial comparing the efficacy and side-effects of piroxicam and indomethacin. Patients were treated for 7 days. Both groups showed a similar degree of improvement in joint tenderness, swelling and pain. Eighty-eight per cent of patients on piroxicam showed a marked or moderate improvement in their injury at the end of the trial and 79% of indomethacin-treated patients. Approximately 50% of patients in both groups resumed full activity within 7 days. One patient, in the indomethacin group, was withdrawn from treatment due to a side-effect.

Is that absolutely true? Reflections on reality in general practice.

Biomedical scientific knowledge appeared to me, as a medical student, to be carved in stone. After many years in general practice it seemed more like it was carved in the shifting sands of time. A feeling of insecurity in diagnosis and treatment followed. There was also a perceived superiority of scientific knowledge over knowledge gained by other means. This did not sit well with my experience in everyday general practice. This article explores a rational framework for change in medical science and a justification for giving equal importance to other forms of knowledge in general practice.

Parent vs burn-injured child self-report: contributions to a better understanding of anxiety levels.

Anxiety disorders are the most commonly reported form of mental health problem among youth, but they often go undiagnosed and untreated. This study examined the relationship between burn-injured youths' self-reported anxiety levels, as compared with their parent's perceptions of their child's emotional well-being. Burn-injured children were invited to voluntarily complete the Child Version of the 41-item survey, Screen for Child Anxiety Related Disorders, which consists of five anxiety subscales as well as a Total Anxiety Score. Parents were invited to complete the Parent Version. Sixty-three parent-child dyads, with girls (57%) and boys (43%), completed surveys. Mothers (73%) fathers (16%), and other caregivers (11%) participated. Youth mean age was 12.63 years and 60% reported visible burn scars. Matched-pairs t-tests were used to compare parent and child reports. Significantly lower mean scores were found between Screen for Child Anxiety Related Disorders Total Anxiety Score--Parent mean score of 10.52 vs the Youth mean score 21.06 (P<.001), as well as on all subscales including; panic disorder/somatic symptoms (P<.001), generalized anxiety disorder (P=.004), social anxiety disorder (separation anxiety (P<.001), and school avoidance (P<0.001). Results indicate that parents may be severely underestimating the psychological well-being of burn-injured youth. Findings emphasize the importance of a comprehensive approach in assessment for anxiety, involving the collection of feedback from both child and parent. Asking children for input into their psychological well-being is important. This study reinforces the need for a course of ongoing patient and parent education.

Radiation-induced fragmentation of diamide extraction agents in ionic liquid diluents.

N,N,N',N'-Tetraalkyldiglycolamides are extracting agents that are used for liquid-liquid extraction of trivalent metal ions in wet processing of spent nuclear fuel. This application places such agents in contact with the decaying radionuclides, causing radiolysis of the agent in the organic diluent. Recent research seeks to replace common molecular diluents (such as n-dodecane) with hydrophobic room-temperature ionic liquids (ILs), which have superior solvation properties. In alkane diluents, rapid radiolytic deterioration of diglycolamide agents can be inhibited by addition of an aromatic cosolvent that scavenges highly reactive alkane radical cations before these oxidize the extracting agent. Do aromatic ILs exhibit a similar radioprotective effect? To answer this question, we used electron paramagnetic resonance spectroscopy to study the fragmentation pathways in radiolysis of neat diglycolamides, their model compounds, and their solutions in the ILs. Our study indicates that aromatic ILs do not protect these types of solutes from extensive radiolytic damage. Previous research indicated a similar lack of protection for crown ethers, whereas the ILs readily protected di- and trialkyl phosphates (another large class of metal-extracting agents). Our analysis of these unanticipated failures suggests that new types of organic anions are required in order to formulate ILs capable of radioprotection for these classes of solutes. This study is a cautionary tale of the fallacy of analogical thinking when applied to an entirely new and insufficiently understood class of chemical materials.

Effects of isometric exercise on the end-diastolic pressure, volumes, and function of the left ventricle in man.

Changes induced in left ventricular (LV) hemodynamics by isometric exercise were analyzed in 43 patients: 30 with coronary heart disease (CAD), four with noncoronary heart disease, nine normal. Volumes were angiographically determined and correlated with left ventricular end-diastolic pressure (LVEDP) both at rest and during the fifth minute of 30% sustained handgrip (HNG). All normals and eight with CAD improved LV function during HNG. LVEDP decreased or remained constant, end-diastolic volume (EDV) decreased, end-systolic volume (ESV) decreased, as ejection fraction (EF) remained constant. None of these eight CAD cases altered their regional LV contraction pattern during HNG. Twenty-five patients, 21 CAD and four nonCAD, showed diminished LV function during HNG. LVEDP increased, EDV decreased, ESV increased, as EF declined. In these 21 CAD patients, at least one major coronary vessel was narrowed 70% or more and, with but two exceptions, was not supported by adequate collaterals. In 18, new asynergic zones developed in previously normally contracting areas or pre-existing asynergic zones extended during HNG.