Symptomatic ischemia in a patient with a single right coronary artery without lesions

Coronary artery anomalies are not a frequent finding, and a single right coronary artery is extremely rare. This anomaly has been included among the potentially serious ones because its association with infarction and sudden death has been reported. We present the case of a female patient who complained of chest pain, showed a positive exercise treadmill test and had a single right coronary artery in the angiography with no stenotic lesions. The pathophysiology and the clinical implications are discussed.     

Application of the integrated safety assessment methodology to the protection of electric systems

The generalization of classical techniques for risk assessment incorporating dynamic effects is the main objective of the Integrated Safety Assessment Methodology, as practical implementation of Protection Theory. Transient stability, contingency analysis and protection setpoint verification in electric power systems are particularly appropriate domains of application, since the coupling of reliability and dynamic analysis in the protection assessment process is being increasingly demanded. Suitable techniques for dynamic simulation of sequences of switching events in power systems are derived from the use of quasi-linear equation solution algorithms. The application of the methodology, step by step, is illustrated in a simple but representative example.     

Hierarchical linear models in psychiatry: A bibliometric study

Development of research methods requires a systematic review of their status. This study focuses on the use of Hierarchical Linear Modeling methods in psychiatric research. Evaluation includes 207 documents published until 2007, included and indexed in the ISI Web of Knowledge databases; analyses focuses on the 194 articles in the sample. Bibliometric methods are used to describe the publications patterns. Results indicate a growing interest in applying the models and an establishment of methods after 2000. Both Lotka’s and Bradford’s distributions are adjusted to the data.     

Identification of novel drug resistance-associated proteins by a panel of rat monoclonal antibodies

It is well established that the rabbit corpus luteum (CL) function depends upon endogenous oestradiol, the major source of which in the rabbit ovary is considered to be the ovarian follicles. The absence of oestradiol formation by the rabbit CL has been previously reported. In a hyperstimulated pseudopregnant rabbit model used in our laboratory which developed a large number of corpora lutea in response to chorionic gonadotrophin (eCG)/hCG, we observed the survival of corpora lutea in vivo, and normal levels of plasma progesterone throughout pseudopregnancy (PP), despite the scarcity or the absence of follicles as a source of the luteotrophic hormone. Measurement of oestradiol in the plasma indicated that it was at high levels and correlated with the number of corpora lutea. This led us to investigate the luteal origin of oestradiol in this model. PP was induced in rabbits by i.m. injection of 200 IU eCG daily for 2 days followed on day 4 by i.m. injection of 200 IU hCG (day 0 of PP). Luteal tissue obtained at days 5, 9 and 12 of PP and cultured for 24 h synthesized oestradiol and testosterone in addition to progesterone. However, under the same conditions, follicles had limited capacity to secrete oestradiol. The presence of an aromatase activity in luteal tissue was confirmed when exogenous testosterone was added to the culture medium. P450aromatase (P450arom) mRNA was found in luteal tissue at days 5, 9 and 12 of PP. Small or large luteal cells, obtained by enzymatic digestion of the tissue followed by centrifugation in a Percoll density gradient, were cultured during several days with or without gonadotrophin or dibutyryl cAMP (dbcAMP). Both types of cells secreted oestradiol. In small cells and luteal tissue, aromatase activity was stimulated (1.5-2-fold) by hCG and dbcAMP. Large cells exhibited a greater capacity to aromatize testosterone than small cells, but aromatase activity was not modified by hCG or by dbcAMP. FSH had no effect on aromatase activity of either luteal cell type. This intrinsic luteal tissue aromatase capacity and the absence of premature regression of corpora lutea despite the limited support of follicular oestrogen, suggest an autocrine and luteotrophic role for this luteal oestrogen.     

The generic enhancement of photochromic dye switching speeds in a rigid polymer matrix

The switching or isomerization speed of photochromic dyes in a rigid polymeric matrix (such as an ophthalmic lens) is generally significantly slower than that observed in the mobile environment of a solution. Here we describe that the attachment of flexible oligomers having a low glass-transition temperature-such as poly(dimethylsiloxane)-to photochromic dyes greatly increases their switching speeds in a rigid polymer matrix. The greatest impact was observed in the thermal fade parameters T(1/2) and T(3/4)-the times it takes for the optical density to reduce by half and three quarters of the initial optical density of the coloured state-which were reduced by 40-95% and 60-99% respectively for spirooxazines, chromenes and an azo dye in a host polymer with a glass-transition temperature of 120 degrees C. The method does not alter the electronic nature of the dyes but simply protects them from the host matrix and provides greater molecular mobility for the switching process. In addition to ophthalmic lenses, the generic nature of the method may find further utility in data recording or optical switching.     

Effect of substitution of aspartame for sucrose on instrumental texture profile of hydrocolloids gelled systems

The effect of substituting aspartame (0.04–0.16% w/w) for sucrose (5–25% w/w) on the instrumental texture profile of three hydrocolloid gelled systems: -carrageenan, gellan gum and -carrageenan/locust bean gum at three different concentrations (0.3, 0.75 and 1.2% w/w) was studied. In gellan gels hardness and chewiness increased with sucrose concentration but not so in either -carrageenan or -carrageenan/LBG gels where no changes in these parameters were detected. Addition of sucrose also produced a small but significant increase in cohesiveness in gellan gels. The effect of sucrose concentration on all texture parameters of gellan gels was higher as gellan concentration increased. Aspartame addition did not affect TPA parameters. TPA results obtained for aspartame gels did not differ from those corresponding to the unsweetened gels considered here. Summarising the above information it can be said that substituting aspartame for sucrose in this type of sweetened gel changed the textural properties and that the changes produced depended on the hydrocolloid type and concentration and on the sucrose concentration replaced.     

Further investigation of the self-presentation hypothesis.

Discusses A. Fontana, E. Klein, E. Lewis, and L. Levine's data supporting their self-presentation hypothesis which maintains that "mental illness" is not an illness at all but a socially undesirable mode of behavior. Several methodological problems in the study are noted. A more reliable means of selecting healthy and sick presenters, as well as a 2 (healthy vs. sick presenter) * 2 (anticipation vs. no anticipation of evaluative feedback) * 3 (positive, negative, no feedback) design, was used in a study with 84 male schizophrenics. A critical mode of self-presentation by feedback interaction predicted by the self-presentation hypothesis was not found. The dependent measure was postscores minus prescores on the WAIS Digit Symbol tests. It is concluded that, at best, self-presentation effects are weak and unobserved by the current investigators (Beta error), or at worst the result of extraneous sources of variation. (18 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Polarographic behaviour of mercaptopyrimidines

The polarographic behaviour at the dropping mercury electrode of several mercapto and methylmercaptopyrimidines with amino substituents has been investigated. The mercapto group gives well defined reproducible anodic waves. Only one electron is involved in the process which is mainly under diffusion control with some adsorption contribution. Between the investigated mercaptopyrimidines only 2-mercaptopyrimidine (with no substituents) shows reduction waves of the pyrimidine nucleus.     

Pharmacological action of a new benzimidazole derivative. II. Protection against bacterial invasion

After difficult intubation in an acromegalic patient was encountered, 7 additional acromegalic patients were studied by measuring the cricoid width and anteroposterior diameter. Cricoid width and anteroposterior diameter were generally found to be narrower than in a group of normal patients. Such narrowing may explain airway problems encountered in acromegalic surgical patients.