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Biomedical subjects

P Duca

Publications and source records attributed to P Duca.

34 records · Page 2Linked to original sources

Coronary angiographic assessment of left posterior hemiblock.

The ECGs of 1,095 patients with coronary angiographic evidence of significant coronary artery disease (greater than or equal to 50% obstructive lesion in at least one major coronary artery) were reviewed. Five patients had left posterior hemiblock (LPHB), an incidence of 0.5%. Three of five patients also had a right bundle branch block (RBBB). Of the five patients with LPHB, all had significant right coronary artery (RCA) disease (four complete occlusions, one 90% obstructive lesion). All five patients having LPHB also had evidence of critical disease (greater than or equal to 75% obstruction) of at least one of the major branches of the left coronary artery; four of the five had complete occlusion of the left anterior descending coronary artery (LAD). The left circumflex coronary artery (CFx) was critically diseased in three patients. The ECGs of four patients showed evidence of only one myocardial infarction while one patient had evidence of an anterior and an inferior infarction. It is concluded that the presence of LPHB in patients with coronary artery disease is an ominous electrocardiographic finding, and is associated with extensive coronary artery disease.

Adult↗

Improved survival after coronary bypass surgery in patients with poor left ventricular function: role of intraaortic balloon counterpulsation.

The operative mortality rate of aortocoronary bypass surgery in 23 patients with poor left ventricular function (ejection fraction 0.30 or less) operated on in 1973-74 was 34.7 percent. The incidence rate of operative myocardial infarction was 30.4 percent. In an attempt to improve survival, intraaortic balloon counterpulsation was used therafter in 25 similar patients. Counterpulsation was instituted preoperatively and continued intra- and postoperatively for 2 to 5 days. Preoperative studies revealed an "unloading" effect of the left ventricle, with significant reductions of systolic arterial blood pressure, end-diastolic pulmonary arterial pressure and end-diastolic left ventricular volume and pressure. Metabolic improvement was demonstrated by the lesser production of myocardial lactate after pacing-induced tachycardia when the ventricle was balloon-assisted. Intraoperatively, blood flow through the vein graft was found to increase with counterpulsation. The rate of operative myocardial infarction was reduced to 4 percent and the mortality rate to 8 percent. In patients who have sustained a significant loss of functioning myocardium, the beneficial hemodynamic and metabolic effects of intraaortic balloon counterpulsation appear to prevent furhter, possibly critical, myocardial damage in the perioperative period.

Assisted Circulation↗

Lactate metabolism as a prognostic index in unstable angina.

Fifty patients evaluated because of unstable angina were followed up for a mean period of 63.7 months. Analysis of transmyocardial lactate metabolism was performed in all patients in addition to coronary angiography and ventriculography. All patients had at least one coronary lesion of great than 75%. Although technically feasible, aortocoronary bypass surgery was not performed on initial hospitalization and all patients were treated medically. Patients were divided into two groups on the basis of lactate metabolism; group A lactate production great than 15%, group B lactate production less than 15% or lactate extraction. There was no difference in left ventricular end-diastolic pressure or ejection fraction between the two groups. A coronary score index was higher in group A than group B (5.45 +/- 2.2 vs 3.13 +/- 1.2) (p less than 0.05). The incidence of myocardial infarction was higher in group A than group B in hospital (44.4% vs. 4.3%, p less than 0.05), and long term (70.3% vs. 17.3%, p less than 0.05). Mortality was higher in group A than group B in hospital (25.9% vs. 0%, p less than 0.05) and long term (66.7% vs. 13%, p less than 0.05). Analysis of lactate metabolism thus provides a prognostic index in unstable angina which complements information obtained by coronary angiography and ventriculography.

Adult↗

Reliability and accuracy in reporting CIN in 14 laboratories. Developing new indices of diagnostic variability in an interlaboratory study. The Working Group for External Quality Control in Cervical Cytopathology.

OBJECTIVE: To report the results of the second phase of a pilot study of an Italian national external quality evaluation program (EQA) aimed at assessing whether participation in the first phase had increased the reliability and accuracy of diagnoses and to what extent. STUDY DESIGN: In the second phase, two sets of cervical smears (similar to the ones examined in the first phase) were circulated among the 14 participating cytologic laboratories throughout Italy. Responses were recorded on a standardized form. Participants were asked to judge the adequacy of each smear and to formulate a diagnosis. They were also asked to recommend management of the patient on the basis of the smear report and to evaluate the degree of diagnostic difficulty of each slide. The results were discussed in workshops, and it was possible to reach a consensus diagnosis on 37 of 40 smears. In the statistical analysis, new indices of diagnostic variability were developed and calculated; a gross index of agreement, unweighted and weighted kappas, analysis of exchangeability, sensitivity and specificity were also estimated. RESULTS: The results of the second phase are similar to those of the first phase and no substantial improvement in accuracy and little reduction in variability were observed. The interventions carried out in this study (discussion between representatives of laboratories of diagnostic differences and reassessment of the most controversial slides) were aimed at increasing consensus among the participating pathologists but were insufficient to change the diagnostic routines in their laboratories. CONCLUSION: It may be advisable to promote two kinds of interlaboratory quality programs with two separate but integrated components: (1) a core component with slides having clear-cut diagnoses, and (2) a continuing education component.

Female↗

[Reference values and tolerance intervals].

Statistical aspects of tolerance intervals estimation are considered and tolerance coefficients for unilateral and central intervals are derived for normally distributed biological variables. The difference between confidence and tolerance interval is explained and application to biological and environmental monitoring, as well as applications to reference values estimation, are exemplified. Tables of unilateral and central coefficients are also produced and reported for different sample dimensions, confidence, and tolerance levels.

Environmental Monitoring↗

[Numerical synthesis of statistical data].

The paper describes the methods currently used for numerical synthesis of statistical data. A review is made of the main properties of the various statistical indices required to describe the central tendency, dispersion and shape of distribution of values. Mode, median, arithmetic mean, harmonic and geometric mean, range, quantiles and standard deviation, asymmetry and kurtosis indices are described and discussed using data drawn from practical experience. Special attention is paid to the errors most frequently incurred using these methods. An appendix supplies details of some of the mathematical properties of the operators described.

Statistics as Topic↗

[Elements of probability calculation. I].

This is the first of a series of articles on probability calculation, consisting of a simple introduction to the definitions of probability. A brief historical background explains some of the reasons for the delay in the development of probability calculation and recalls the main problems that had to be faced, the solution of which marked the birth of the theory of probability. Classical, frequentist and subjective approaches are addressed and their relative merits and weaknesses are discussed.

Probability↗

[Elements of probability calculation--II].

This is the second part of an introduction to probability calculation and covers basic concepts such as conditional and simple probabilities and independent events and also a definition of two fundamental laws, those of addition and multiplication, which permit a correct combination of probabilities. Explanation of probability concepts and ideas is illustrated with the aid of examples from the field of screening tests. Bayes theorem is derived by applying the addition and multiplication laws to conditional and simple probabilities.

Bayes Theorem↗

[The cases of accident in the ceramic tile industry in relation to the age and job seniority of the workers].

A study was made of 3,368 workers in 36 ceramic plants in the Scandiano area (Reggio Emilia, Italy) during the year 1990; 403 had an accident during the observation period. The incidence and severity of the accident were correlated to age, job (low, intermediate, high accident risk), duration of employment as at 1.1.1990 (> 24, 12-24, > 24, 12-24, < 12 months, engaged during 1990). Logistic regression analysis, survival analysis and RIDIT analysis were performed using GLIM and EGRET statistical packages. Risk: ORs for intermediate and high-risk jobs vs low-risk jobs were 1.3 (1.0-1.7 95% confidence limits) and 1.7 (1.3-2.3), respectively, adjusted for duration of employment; ORs for the 12-24, < 12 months, engaged during 1990 categories vs the > 24 months category were 1.5 (1.1-2.0), 1.7 (1.3-2.2), 2.1 (1.6-2.8) respectively. Severity: the mean RIDIT of the > 44-year-old vs < 30-year-old workers was 0.6 (0.53-0.67).

Accidents, Occupational↗