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Biomedical subjects

L Rossi

Publications and source records attributed to L Rossi.

At least 289 records · Page 16Linked to original sources
PubMed1991

[Value of serial exercise tests after coronary angioplasty in relation to extension of heart disease and the degree of revascularization].

With the aim of investigating the functional result of the coronary angioplasty (PTCA) and verifying the predictive value of the exercise test for detecting restenosis, 165 patients who underwent successful PTCA were evaluated through exercise stress tests performed 10, 75 and 165 days after PTCA and through coronary angiography performed 5 to 6 months after PTCA. The percentage of negative tests and the rate-pressure product (RPP) increased significantly with respect to the tests performed before PTCA, both in patients with single-vessel and those with multivessel disease. Maximal ST segment depression and ST/HR were significantly reduced only in patients with complete revascularization. The percentage of positive tests 10 days after PTCA was lower in patients with single-vessel than in those with multivessel disease (2.5% versus 10.8%) and, of the latter, in patients with complete rather than incomplete revascularization (0% versus 13.5%). In patients with complete revascularization, the mean exercise time rose significantly (703 s versus 538 s). The percentage of positive tests increased progressively with time, in accordance with probable increasing restenosis. In comparison with the results of angiography, sensitivity of the exercise stress test proved to be poor (59%), especially in patients with single-vessel disease (45%), while the specificity was very high (98%). The predictive value of a negative test was 77% in patients with multi-vessel and 87% in patients with single-vessel disease. The predictive value of a positive test was over 90% in both groups of patients.

Adult↗
PubMed1991

[Syndrome of multiple cholesterol embolism after parenteral streptokinase therapy of acute myocardial infarct: description of an autopsy case].

Syndrome caused by multiple cholesterol embolism can be seen as a complication in patients affected by acute myocardial infarction, treated with streptokinase thrombolytic therapy. Fragments of atheromatous plaques may embolize and occlude arterial vessels in different organs. Only the histological examination can give a reliable diagnosis, because symptomatology changes according to different localization of the emboli. An emblem case of this pathology observed by the Authors is described in this article.

Cholesterol↗
PubMed1991

New heterocyclic derivatives of benzimidazole with germicidal activity--IX--HPLC detection of 5-fluoro-2-(5'-nitro-2'-furyl)benzimidazole (F-O-NO2) in biological samples.

The HPLC technique for the isolation and quantitation of 5-fluoro-2-(5'-nitro-2'-furyl)benzimidazole (F-O-NO2), previously described by the same Authors, in biological samples from mice is reported. Evidence is given that the highest biological concentration and the time needed for reaching it depend both on the dose and on the administration route. In fact, almost the same maximal biological concentration of F-O-NO2 (about 0.18 micrograms/mouse) is reached after 60 min from either 40 mg/Kg IP or 200 mg/Kg os drug administration, whereas the maximal biological concentration of F-O-NO2 (5.75 micrograms/mouse) is reached after 30 min from 120 mg/Kg IP drug administration.

Animals↗
PubMed1991

[The echo-dipyridamole test early after acute myocardial infarct: echocardiographic aspects and angiographic correlations].

To assess whether the different mechanical effects of intravenous dipyridamole were correlated with the location and distribution of the coronary arteries stenosis, 98 patients underwent high dose DET 8-10 days after an acute myocardial infarction. Left ventricular regional wall segments were identified in multiple views; a vascular territory was assigned to each coronary vessel. DET was positive in 68.4% of the patients (67/93), 59% (23/39) of those with single vessel disease, and 81% (44/54) of those with multivessel disease. Four different mechanical patterns of positivity of DET were observed: 1) marked worsening of wall motion in the same region showing asynergy (type I); 2) development of new wall motion abnormality adjacent to the infarct zone and located in the same vascular region (type II); 3) development of new wall motion abnormality adjacent to the infarct zone, but located in a different vascular region (type III); 4) development of transient remote asynergy (that is, a new wall motion abnormality in a region normal at rest and not directly adjacent to the infarct zone, type IV). Types I and II (asynergies in the infarct zone coronary bed) were found in patients both with single vessel disease or multivessel disease; by contrast, type III and IV were almost exclusively found in patients with multivessel disease (24/54 and 14/54 respectively) and occasionally in patients with single vessel disease (2/39 and 1/39 respectively). Thus, these two mechanical behaviours during dipyridamole infusion showed to be highly specific for predicting multivessel disease (95% and 97% respectively, sensitivity 44% and 26% respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

Stress testing in the period after infarction.

Dipyridamole echocardiography is gaining popularity as an exercise-independent diagnostic method in patients with suspected or demonstrable coronary artery disease. To assess its safety, feasibility, and diagnostic accuracy in patients recovering from uncomplicated acute myocardial infarction, 131 patients had the test before hospital discharge. The results were compared with those of maximum treadmill testing. We found that dipyridamole-induced transient asynergy remote from the infarct zone was more sensitive (74% versus 53%, p less than 0.05) and specific (97% versus 68%, p less than 0.01) than treadmill testing for detecting multivessel coronary artery disease. In a subgroup of 42 patients treated with thrombolytic therapy, dipyridamole echocardiography was able to detect in 27 the presence of jeopardized but viable myocardium in the infarct zone. An excellent correlation was found between dipyridamole echocardiography responses and infarct vessel patency. Finally, the prognostic impact of dipyridamole echocardiography on patients recovering from acute myocardial infarction was assessed in a consecutive series of 151 patients. Eighteen months of event-free survival was significantly different in patients with positive versus negative dipyridamole echocardiography results (76.1% versus 50.8%, p less than 0.01). The test was also superior to treadmill testing in predicting cardiac events. Thus, dipyridamole echocardiography performed early after acute myocardial infarction is safe, feasible, and accurate for predicting the extent of coronary artery disease and 18-month clinical outcome.

Coronary Disease↗
PubMed1990

Cytotoxicity of a low molecular weight Cu2Zn2 superoxide dismutase active center analog in human erythroleukemia cells.

The cytotoxicity of SOD-mimics was studied in human K562 erythroleukemia cells. CuPUPY, a low molecular weight copper complex with properties typical of a Cu2Zn2 SOD active center analog was shown to display pronounced toxicity upon incubation with human K562 erythroleukemia cells, while the ligand, CuSO4 or CuEDTA did not affect vitality. Externally added catalase decreased the cytotoxic effects of CuPUPY by 50% indicating an involvement of hydrogen peroxide in toxicity. An increased oxygen uptake and glutathione oxidation by K562 cells in the presence of CuPUPY suggested that toxicity might be due to a copper-mediated redox-cycle. In fact addition of glutathione to a solution of CuPUPY resulted in glutathione oxidation, O2-consumption and H2O2-generation. CuPUPY proved to be less toxic to human lymphocytes than to K562 cells. This selectivity may be related to the low content of antioxidative enzymes in K562 cells.

Binding Sites↗
PubMed1990

Generation of daunomycin radicals on the outer side of the erythrocyte membrane.

The generation of the daunomycin semiquinone was studied in intact red blood cells under CO atmosphere by ESR spectroscopy. The undialyzed hemolysates and the spin broadening agent chromium oxalate quenched the ESR signal, suggesting external location of the ESR-detectable radicals and their slow diffusion inside. A constant outward flow of O2- was detected by monitoring the approach to the steady state of the ESR signal of Cu,Zn superoxide dismutase externally added to red blood cells plus daunomycin in air. This suggests a reductase on the outer side of the erythrocyte membrane as the source of daunomycin radicals.

Daunorubicin↗
PubMed1990

[Pseudo-hyperaldosteronism caused by licorice. Pathogenetic considerations and presentation of a clinical case].

A case of pseudo-hyperaldosteronism secondary to prolonged daily ingestion of liquorice is reported. Extreme severity of hypokalemia and of the ensuing neuro-muscular impairment characterized this case. The pathogenetic features leading to the glycyrrhizic acid dependent sodium retention are thoroughly discussed, on the basis of the latest literature. The authors stress the fact that public opinion is to a large extent unaware of risks due to prolonged ingestion of liquorice derivatives.

Glycyrrhetinic Acid↗
PubMed1990

Anti-double-stranded DNA antibodies in the healthy elderly: prevalence and characteristics.

Using Crithidia luciliae fluorescent assay a significant prevalence (7.6%; P less than 0.006) of anti-double-stranded DNA antibodies was found in a healthy old population. A negative enzyme-linked immunosorbent assay for anti-total histone antibodies excluded a false-positive reaction. Anti-double-stranded DNA antibodies in the aged differed from those found in patients with systemic lupus erythematosus and were characterized by a low titer (95.6% of cases), belonging to the IgA class alone (95.6%), no complement-fixing ability (100%), and negativity to Farr assay (100%). It is concluded that, in elderly subjects without signs and symptoms of disease, including systemic lupus erythematosus, such a peculiar anti-double-stranded DNA antibody may be detected.

Adult↗
PubMed1990

A nonlinear three-compartment model for the administration of 2',3'-dideoxycytidine by using red blood cells as bioreactors.

A non-linear three-compartment model is proposed to describe a new strategy for the administration of 2',3'-dideoxycytidine (ddCyd) in the treatment of HIV infections. The drug is injected after having been encapsulated in a non-diffusible form (ddCMP) into erythrocytes. Numerical solutions show that by this treatment the highest ddCyd blood concentration is strongly reduced and in turn its toxicity, while long-lasting therapeutic effect is assured. The model is compared with experimental data in vitro.

Delayed-Action Preparations↗
PubMed1990

Sudden death in young competitive athletes: clinicopathologic correlations in 22 cases.

PURPOSE: To investigate the pathologic substrates of sudden death in young competitive athletes. PATIENTS AND METHODS: Twenty-two cases of sudden death in young competitive athletes occurring in the Veneto region (northern Italy) in the period January 1979 to December 1989 were studied by postmortem examination. The athletes included 19 males and three females, ranging in age from 11 to 35 years (mean, 23 years). RESULTS: In 18 cases, sudden death occurred during (16 cases) or immediately after (two cases) a competitive sport activity. In 10 subjects, sudden death was apparently the first sign of disease. Postmortem examination disclosed that this fatality was due to arrhythmic cardiac arrest in 17 cases; among these, right ventricular cardiomyopathy, also known as "right ventricular dysplasia," was the most frequently encountered cardiovascular disease (six cases), followed by atherosclerotic coronary artery disease (four cases), conduction system pathology (three cases), anomalous origin of right coronary artery from the wrong aortic sinus (two cases), and mitral valve prolapse (two cases). In two athletes, the abrupt lethal complication was "mechanical" and consisted of pulmonary embolism and rupture of the aorta; in three athletes, death was due to a cerebral cause. All athletes with right ventricular cardiomyopathy died during effort, and most had a history of palpitations and/or syncope. Whenever available, electrocardiographic (ECG) tracings showed inverted T waves in precordial leads and/or left bundle branch block ventricular arrhythmias. CONCLUSIONS: Clinicopathologic correlations indicate that in the Veneto region of Italy, right ventricular cardiomyopathy is not so rare among the cardiovascular diseases associated with the risk of arrhythmic cardiac arrest, and seems to account for the majority of cases of sudden death in young athletes; this disorder can be suspected during life on the basis of prodromal symptoms and ECG signs.

Adolescent↗
PubMed1990

Gallbladder motility in cholesterol gallstone disease. Effect of ursodeoxycholic acid administration and gallstone dissolution.

Gallbladder motility was evaluated by ultrasonography in 75 cholesterol gallstone patients and in 77 matched control subjects. All 75 gallstone patients were candidates for oral bile acid therapy (radiolucent gallstones, less than 2 cm in diameter, in well-opacified gallbladder), and 38 of them were also studied during ursodeoxycholic acid administration. An additional 20 gallstone patients were studied 1 year after confirmed gallstone dissolution with oral bile acids. Gallstone patients showed significantly greater fasting and residual volumes, a decreased percent of gallbladder emptying, but a similar absolute emptying and emptying rate compared with the control subjects. Greater fasting volumes and reduced percents of gallbladder emptying were also found in gallstone-free patients who achieved complete dissolution with oral bile acids. After ursodeoxycholic acid administration, fasting gallbladder volumes were greater, and percents of gallbladder emptying were further decreased than in untreated gallstone patients. In conclusion, greater fasting volumes, and not reduced gallbladder contractility, account for the defective gallbladder function in radiolucent (cholesterol-rich) gallstone patients. This condition is likely to precede, and possibly to promote, gallstone formation because it persists after gallstone dissolution. Ursodeoxycholic acid administration worsens the defect observed in gallstone patients. This finding also suggests, although indirectly, that the expected normalization of cholesterol saturation during oral bile acid administration is not paralleled by an improvement in gallbladder function.

Adolescent↗
PubMed1990

In vivo accelerated acetaldehyde metabolism using acetaldehyde dehydrogenase-loaded erythrocytes.

Human erythrocytes were loaded with homogeneous acetaldehyde dehydrogenase (AcDH) purified from Alcaligenes Eutrophus (an enzyme species with an apparent Km for acetaldehyde similar to the mitochondrial enzyme), using an encapsulation procedure based on hypotonic haemolysis, isotonic resealing and reannealing. The AcDH-overloaded erythrocytes contained 1.55 +/- 0.25 I.U. of AcDH activity per ml of packed erythrocytes, a value 12-15 times higher than that of corresponding unloaded or native red cells. The AcDH-loaded erythrocytes were found to metabolize 4 +/- 0.8 mumol of acetaldehyde/hr/ml of red blood cells, whereas the glycolytic activity was almost unmodified. Estimates of intracellular adenine nucleotides showed 50% ATP decay in the AcDH-loaded cells when incubated in the presence of acetaldehyde concentrations higher than 50 microM, whereas the [NAD+]/[NADH] ratio was strongly decreased but to the same extent as in control cells, suggesting that this was due to the acetaldehyde itself and not to the presence of encapsulated AcDH. Similar results were obtained using mouse erythrocytes. AcDH-overloaded mouse red blood cells from donor animals were also injected intraperitoneally into compatible recipients (Balb/C) and 80 to 85% of these were found to enter into circulation within 24 hr and to circulate with a half-life of 6-7.3 days (normal half-life 11 days). Following an acute dose of ethanol (2g/kg intraperitoneally), blood levels of acetaldehyde were significantly lower in mice receiving the AcDH-loaded erythrocytes than in controls. Blood levels of ethanol were also lower in the treated mice compared to controls. These results show that AcDH-overloaded erythrocytes can perform in vitro and in vivo as bioreactors improving alcohol and acetaldehyde metabolism, and suggest that administration of these cells to alcoholic patients could be of value in restoring to normal, or improving, alcohol and acetaldehyde metabolism.

Acetaldehyde↗
PubMed1990

Autoantibodies of systemic rheumatic diseases in the healthy elderly.

Antinuclear antibodies, anticardiolipin antibodies and IgM rheumatoid factor were determined in 300 healthy aged subjects, comparing their prevalence to that in 100 healthy subjects aged between 19 and 44 years and 352 patients under 65 years of age, affected by various systemic rheumatic diseases. Increased production of IgM rheumatoid factor and antinuclear and anticardiolipin antibodies was found as characteristic of aged humans, and suggested that a correction for age should be considered in evaluating the clinical significance of autoantibody profiles in elderly patients.

Adult↗
PubMed1990

Acid phosphatase activity in microfilariae of Setaria labiato-papillosa and comparison with other blood microfilariae of dog and horse origin.

Acid phosphatase activity was demonstrated in smears of Setaria labiato-papillosa microfilariae by the naphthol AS-TR-phosphate method. The staining was restricted to 3 distinct sites, corresponding to the excretory pore, the inner body and the anal pore. This staining pattern was compared with those of Dirofilaria immitis, Dirofilaria repens and a Setaria of horse origin.

Acid Phosphatase↗
PubMed1990

[Late potentials and computerized averaging electrocardiogram in acute myocardial infarct: evaluation of myocardial reperfusion].

Myocardial reperfusion after thrombolytic therapy in acute myocardial infarction can be directly demonstrated with coronary angiography or it can be assessed thanks to indirect markers of reperfusion, such as modifications in the "averaged" QRS complex. We assessed the presence of late potentials in 37 patients within 5 hours of acute myocardial infarction onset and evaluated their disappearance or modification after reperfusion. Signal-averaged electrocardiogram, obtained computerizing QRS complexes filtered through Simson's bidirectional filter (25-250 Hz), was serially recorded in each patient: at admission, as well as 12 hours, 3 and 10 days following urokinase and/or heparin therapy. Other indirect markers of reperfusion (incidence of ventricular arrhythmias, serum CK-MB level, ST elevation) were contemporaneously evaluated. All patients underwent coronary angiography between 6 and 83 days after acute myocardial infarction. Late potentials (Total QRS greater than 115 ms; Under 40 microV greater than 39 ms; RMS Last 40 ms less than 25 microV) were present only in 25% of patients, and they always disappeared after successful thrombolysis. On the contrary if ischemia-related vessel occlusion persisted, late potentials persisted as well or else were first recorded on the 3rd or 10th day following acute myocardial infarction. Quantitative analysis of the "averaged" QRS complex showed a statistically significant reduction in QRS duration (-9.1 +/- 12.7 ms) 3 days after acute myocardial infarction in reperfused patients (group A, n = 24), while no significant reduction in the total QRS (-1 +/- 6.7 ms) was observed in non-reperfused cases (group B, n = 13), (p less than 0.05 group A vs group B). So, 10 ms reduction in total QRS duration was a good marker of reperfusion, with specificity = 92% and sensitivity = 54%; marker sensitivity was even higher (= 79%) when coupled with serum CK-MB peak within 12 hours of therapy (diagnostic accuracy = 84%). In conclusion, even if late potentials have a low prevalence in acute myocardial infarction (25%) their disappearance correlates with myocardial reperfusion. Furthermore, a reduction in total QRS duration greater than or equal to 10 ms can itself be a good marker of successful thrombolysis.

Adult↗
PubMed1990

[Intra- and perioperative arrhythmia and ischemic signals in myocardial revascularization patients].

In order to evaluate perioperative electrical cardiac disturbances and ST segment changes, 42 patients (38 M, 4 F, aged 57 +/- 6 ys) were studied using 24-hour Holter monitoring before, during and after coronary bypass surgery. In the 4-6 hours before cardioplegic arrest, 38% of patients had ST segment changes. No patient and malignant arrhythmias. The injection of cold cardioplegic solution was followed by bradycardia, ventricular tachycardia, ventricular fibrillation and isoelectric line within 2-4 minutes. After aortic declamping, 30 patients were defibrillated. Impulse formation and conduction disturbances, found in 55% of patients, solved themselves in 1 to 60 minutes. Bundle branch block continued in just 4 cases. A total of 59% of patients had ST segment elevation for 14 +/- 14 minutes and 19% had ST segment depression for 19 +/- 20 minutes. Successive transient ST segment changes were detected in 38% of patients. Sustained ventricular tachycardia occurred during 2 ischemic episodes. Impulse formation and conduction disturbances were not related to the duration of cardiac arrest or ventricular fibrillation, but were more frequent and lasted longer in patients with incomplete revascularization. Transient ST segment depression far from aortic declamping correlated with preclamping ischemia. Transient ST segment elevation correlated with incomplete revascularization. We concluded that ECG signs of intraoperative damage were reversible. Moreover, perioperative transitory ischemia was frequent but could be prevented by coronary active drug administration. On the other hand incomplete revascularization was associated with electrical disturbances and ischemia.

Aged↗