1,803 research outputs found
Relationship between oxidative stress, lipid peroxidation, and ultrastructural damage in patients with coronary artery disease undergoing cardioplegic arrest/reperfusion.
No full textOBJECTIVE:
In animal models, formation of oxidants during postischemic reperfusion may exert deleterious effects ("oxidative stress"). Cardioplegic arrest/reperfusion during cardiac surgery might similarly induce oxidative stress. However, the phenomenon has not been precisely characterized in patients, and therefore the role of antioxidant therapy at cardiac surgery is a matter of debate. Thus, we wanted to ascertain whether the relationship between oxidant formation and development of myocardial injury also translates to the situation of patients subjected to cardioplegic arrest.
METHODS:
In 24 patients undergoing coronary artery bypass, trans-cardiac blood samples and myocardial biopsies were taken before cardioplegic arrest and again following reperfusion.
RESULTS:
Cardiac glutathione release (marker of oxidant production) was negligible at baseline (0.02+/-0.04 micromol/L), but it increased 15 min into reperfusion (1.10+/-0.40 micromol/L; p<0.05); concomitantly, myocardial concentration of the antioxidant ubiquinol decreased from 144.5+/-52.0 to 97.6+/-82.0 nmol/g (p<0.05). Although these changes document cardiac exposure to oxidants, they were not accompanied by evidence of injury. Neither coronary sinus blood nor cardiac biopsies showed increased lipid peroxide concentrations. Furthermore, electron microscopy showed no major ultrastructural alterations. Finally, full recovery of left ventricular systolic and diastolic function was observed.
CONCLUSIONS:
Careful investigation reveals that while oxidant production does occur during cardiac surgery in patients with chronic ischemic heart disease, cardiac oxidative stress may not progress through membrane damage and irreversible injury
Clinical use of transoesophageal atrial stimulation in terminating ventricular tachycardia
No full textThis study was performed to evaluate whether transoesophageal atrial pacing could also stop ventricular tachycardias with low rates and no haemodynamic impairment. Prior to resorting to ventricular endocardial pacing, seven male patients, aged between 15 and 73 years, were treated by transoesophageal atrial pacing for 10 spontaneous episodes of sustained ventricular tachycardia at rates between 105 and 160 beats per minute, without haemodynamic impairment. When atrial pacing did not allow ventricular capture, atropine sulphate was administered. Transoesophageal atrial pacing led to ventricular capture in seven episodes, which made overdriving possible, and blocked six episodes of ventricular tachycardia. In no case did transoesophageal atrial pacing lead to an acceleration of ventricular tachycardia or to degeneration into ventricular fibrillation. Transoesophageal atrial pacing can block low-rate sustained ventricular tachycardias (≤ 150 beats per minute). For low-rate sustained ventricular tachycardias without haemodynamic impairment, transoesophageal atrial pacing can thus be used as the method of choice thanks to its good ratio of risk to efficiency. © 1990
Recuerdos de Massimo.
No full textEl presente ensayo recuerda la rica relación personal e intelectual entre Massimo Pavarini e Iñaki Rivera Beiras desde que el segundo conoció siendo muy joven a Pavarini. En ese sentido, el trabajo recuerda los inicios de su fecunda relación en la ciudad de Bologna cuando Iñaki Rivera acudía a presentar a Massimo Pavarini los desarrollos de lo que sería su tesis doctoral. Las contribuciones de Pavarini al proceso de aprendizaje de Rivera, en el terreno de una epistemología crítica en la penología contemporánea, son analizados como un homenaje a la memoria y a la obra del autor italiano, tras su fallecimiento en septiembre de 2015.This paper recalls the rich personal and intellectual relationship between Massimo Pavarini and Iñaki Rivera Beiras. In that sense , the work recalls the beginning of his fruitful relationship in the city of Bologna when Iñaki Rivera came to present Massimo Pavarini’ developments in what would be his PhD thesis. Pavarini contributions to the learning process of Rivera, on the ground of a critical epistemology in contemporary penology , are analyzed as a tribute to the memory and to the work of Italian author, after his death in September 2015 .El presente ensayo recuerda la rica relación personal e intelectual entre Massimo Pavarini e Iñaki Rivera Beiras desde que el segundo conoció siendo muy joven a Pavarini. En ese sentido, el trabajo recuerda los inicios de su fecunda relación en la ciudad de Bologna cuando Iñaki Rivera acudía a presentar a Massimo Pavarini los desarrollos de lo que sería su tesis doctoral. Las contribuciones de Pavarini al proceso de aprendizaje de Rivera, en el terreno de una epistemología crítica en la penología contemporánea, son analizados como un homenaje a la memoria y a la obra del autor italiano, tras su fallecimiento en septiembre de 2015
Predoni a casa nostra e il geografo solidale: Massimo Quaini tra terra e acqua
No full textIn accordance with the main goals of this collection of essays in honour of Massimo Quaini, the text focuses on a peculiar character of the Ligurian geographer’s sensibility, his attention to landscape protectionresearch activity developed in the context of the humanistic geography. Starting from a personal narrative based on his own reminiscences and neglected memories, the author tries to shed light on the relationships between civil commitment and cultural reflection which characterize environmental sensitivity, bringing together his interests with Quaini’s emotional geographies. Finally, some of Quaini’s everyday practicalities are highlighted as the easiest doorway to improve the cognitive procedures of cultural geography
Is Felix Salten the author of the Mutzenbacher novel (1906)? Yes and no
No full textJosefine Mutzenbacher oder die Geschichte einer Wienerischen Dirne von ihr selbst erzählt, published in Vienna in 1906, represents one of the most fascinating cases of attribution of authorship in German literature. Although Josefine Mutzenbacher is usually attributed to Felix Salten, the author of the world-famous Bambi (1923), the novel’s authorship has never been confirmed, and many other candidates have been named as potential authors. Among them is Arthur Schnitzler, who published Reigen, a cycle of amorous adventures in Viennese society, in 1903. Some scholars, instead, have attributed the novel to such lesser-known writers as Ernst Klein and Willi Handl. The controversy surrounding the authorship of Josefine Mutzenbacher was the starting point for our stylometric analyses, and our results help to answer some unresolved questions in a debate that has lasted for more than 100 years. The analyses were performed using the R package Stylo, which enables an efficient application of Burrows’ Delta and its variants. Focusing on both the entire text and on the final pages, two different types of analysis were carried out: one combines 1200 different stylometric methods to compare the candidate authors Salten, Schnitzler, Bahr, Altenberg, Hofmannsthal, Klein and Handl; the other verifies the attribution using the ‘impostors’ method. The results show that the most probable author is Felix Salten, while none of the candidates could be identified as the author of the final pages, confirming the hypothesis that the text was left unfinished by Salten and completed by an as-yet-unidentified ghost-writer
Plastid Genotyping Reveals the Uniformity of Cytoplasmic Male Sterile-T Maize Cytoplasms
No full textCytoplasmic male-sterile (CMS) lines in maize (Zea mays) have been classified by their response to specific restorer genes into three categories: cms-C, cms-S, and cms-T. A mitochondrial genome representing each of the CMS cytotypes has been sequenced, and male sterility in the cms-S and cms-T cytotypes is linked to chimeric mitochondrial genes. To identify markers for plastid genotyping, we sequenced the plastid genomes of three fertile maize lines (B37, B73, and A188) and the B37 cms-C, cms-S, and cms-T cytoplasmic substitution lines. We found that the plastid genomes of B37 and B73 lines are identical. Furthermore, the fertile and CMS plastid genomes are conserved, differing only by zero to three single-nucleotide polymorphisms (SNPs) in coding regions and by eight to 22 SNPs and 10 to 21 short insertions/deletions in noncoding regions. To gain insight into the origin and transmission of the cms-T trait, we identified three SNPs unique to the cms-T plastids and tested the three diagnostic SNPs in 27 cms-T lines, representing the HA, I, Q, RS, and T male-sterile cytoplasms. We report that each of the tested 27 cms-T group accessions have the same three diagnostic plastid SNPs, indicating a single origin and maternal cotransmission of the cms-T mitochondria and plastids to the seed progeny. Our data exclude exceptional pollen transmission of organelles or multiple horizontal gene transfer events as the source of the mitochondrial urf13-T (unidentified reading frame encoding 13-kD cms-T protein) gene in the cms-T cytoplasms. Plastid genotyping enables a reassessment of the evolutionary relationships of cytoplasms in cultivated maize.Peer reviewe
A cidade, de Massimo Cacciari
No full textThis review presents a summary of the series of seminars presented by Massimo Cacciari at the Centro Sant´Apollinare de Fiesole, transcribed and edited by Tonino Rasuto. The work, entitled The city, brings reflections on what the author understands as the origin of urban configurations, more precisely what he classifies as the post-metropolis, the city-territory, which has its formation linked to the principles of Greek polis and of the Roman civitas. Finally, the author defines the potential of place and the geography of events, based on a methodological path of understanding the phenomena that were able to reframe the meaning of the city for the human being.Apresenta-se nesta resenha, uma síntese da série de seminários apresentados por Massimo Cacciari no Centro Sant´Apollinare de Fiesole, transcrita e editada por Tonino Rasuto. A obra, de título A cidade, traz reflexões acerca do que o autor entende como a origem das configurações urbanas, mais precisamente o que classifica como a pós-metrópole, a cidade-território, que tem sua formação ligada aos princípios da pólis grega e da civitas romana. Por fim, o autor define o potencial de lugar e da geografia de acontecimentos, a partir de um caminho metodológico de entendimentos dos fenômenos que foram capazes de ressignificar o sentido de cidade para o ser humano
Calcolo di stabilità della cupola del Teatro massimo di Palermo /
No full textMode of access: Internet.Bound in original printed wrappers; inscribed to G. Pini by the author on front wrapper
[The early hemodynamic and hormonal changes in patients with left ventricular dysfunction].
No full textThe aim of this study was to highlight a different hormonal and hemodynamic pattern in patients with mild cardiomyopathy. For this purpose, we studied subjects with mild heart failure (CHF; NYHA class I and II; post-ischemic and idiopathic) who underwent an isotonic saline load (SL) (0.22 ml/kg/min of 0.9% NaCl for 120 min). A second group of age- and sex-matched normal subjects (C) was studied as a control. Basal hormonal and hemodynamic values of the 2 groups differed only in atrial natriuretic factor (ANF), left ventricular end-diastolic diameter and ejection fraction (EF). There were, on the contrary, no differences in basal plasma renin activity (PRA) and plasma aldosterone (PA) values. After SL, in C, percent changes in EF, cardiac output and ANF values were significantly higher than in CHF while total peripheral resistances increased only in CHF but not in C. In both groups there were decrements of PRA and PA, but these responses were significantly higher in C than in CHF. In conclusion, our results show that hormonal, renal and hemodynamic responses to salt/volume load are compromised in the early asymptomatic phase of heart failure. These abnormalities may predict the progressive deterioration of cardiac function, and may indicate appropriate therapeutic interventions since the early phases of the disease
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