Search PubMed⌕ Search

Biomedical subjects

R Albiero

Publications and source records attributed to R Albiero.

At least 55 records · Page 3Linked to original sources
PubMed1995

Digital stress-echocardiography using a public domain program for the Macintosh personal computer.

Left ventricular wall motion abnormalities secondary to stress-induced myocardial ischemia can be detected with difficulty by mentally comparing echocardiographic images sequentially recorded on videotape. Digital stress-echocardiography, a combination of ultrasound imaging and digital archiving technologies, at least partially can overcome this problem: the technique is based on reviewing images at rest and after stress (exercise or pharmacological) side by side in dual- or quad-screen digital format, in a synchronized cine-loop, as if obtained simultaneously. This technique however is presently not widely used, due to the high cost of most commercially available systems. We have developed a digital stress-echo system, which is easy to use and relatively inexpensive, running on a Macintosh II personal computer with 8-bit graphics. The 2-D echocardiographic images recorded on videotape are digitized offline using a video digitizing board. The image can be displayed and analyzed using the public domain NIH image software developed by Wayne Rasband, without loss in image quality and resolution, particularly if using Super-VHS videotape. We have made a macro procedure for the montage in a quad-screen format of four digital recorded echocardiographic cardiac cycles of six frames that takes only a little more time than commercially available systems. In conclusion, the use of a personal computer and low-cost software may help to make digital stress-echo techniques more widely feasible in the clinical setting and increase the diagnostic power of the ultrasound technique in the evaluation of patients with known or suspected coronary artery disease.

Coronary Disease↗
PubMed1994

Effect of vitamin A administration on resistance of rat heart against doxorubicin-induced cardiotoxicity and lethality.

The peroxyl radical-scavenging activity of vitamin A has been exploited to obtain protection against peroxidative damages induced in rat heart by administration of an acute dose of doxorubicin (10 mg/kg, in vein). Peroxidative lesions were evaluated by both biochemical and histological assays, 48 hr after the injection of doxorubicin. Heart tissue from rats receiving doxorubicin showed a marked increase of protein carbonyl levels, and of membrane conjugated dienes, as well as a decrease of membrane protein thiols. Abnormal chemistries, including a large increase of the activity of serum lactate dehydrogenase and creatine phosphokinase, an index of the myocardial damage caused by doxorubicin, were also observed. Pretreatment of rats with 25 I.U./kg b.wt. of vitamin A, once a day for 2 days, before injecting doxorubicin, substantially reduced the peroxidative damage to heart lipids and proteins, and markedly lowered the serum values of lactate dehydrogenase and creatine phosphokinase to values close to those of control rats. The significant prevention of doxorubicin-induced cardiomyopathy by vitamin A was evident from the histopathological pattern observed after light microscopy. The dosage of vitamin A useful to obtain the protective effect appears safe and does not injure the liver, as indicated by light microscopy of the tissue. A survival study, carried out by injecting rats with a single injection of 10 mg/kg of doxorubicin, showed that pretreatment with 25 I.U. of vitamin A per kg significantly increased survival rate of the animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Effects of captopril on myocardial protection during cardioplegia.

UNLABELLED: The study aimed at checking effects exerted by captopril (C) on human myocardial ACE system as well as the role played by tissue ACE inhibition in reducing reperfusion damage. A human experimental model was used during cardioplegia due to aorto-coronary-by-pass (CABG). Fifty-four patients with coronary artery disease affecting 3 vessels having suffered from acute myocardial infarction anterior (AMI-ant), homogeneous as far as ejection fraction (35-55%), number of grafts (3), clamping time, age and sex, were randomised in a double blind experiment, and were given captopril or placebo (P). A total of 4 mg/l Captopril was mixed into the cardioplegic solution with blood according to the method of Buckberg (Buckberg GD. J Thorac Cardiovasc Surg 1987; 93: 127-139). Eight samples (blood/perfusate) were obtained from each patients and norepinephrine (NE), epinephrine (E) were assayed using an HPLC technique. Angiotensin I was assayed by RIA. CK was also assayed (units/ml). Blood/perfusate samples were taken during CABG: (1) pre-pump; (2) pump sample; (3) pump preclamping; (4) coronary sinus; (5) coronary sinus sample during reperfusion; (6) coronary sinus during warm reperfusion; (7) after clamping sample; (8) after decanulation; RESULTS: Captopril group (29 patients): angiotensin I: (1) 8.15; (2) 7.0; (3) 7.31; (4) 8.45; (5) 8.93; (6) 8.73; (7) 9.07; (8) 9.40; versus placebo: (1) 7.09, (2) 7.43; (3) 7.80; (4) 9.31; (5) 9.01; (6) 8.35; (7) 8.85; (8) 8.07 ng/ml, probability, not significant.(ABSTRACT TRUNCATED AT 250 WORDS)

Angiotensin I↗
PubMed1993

Vitamin A inhibits doxorubicin-induced membrane lipid peroxidation in rat tissues in vivo.

The antioxidant activity of vitamin A against lipid peroxidation induced by doxorubicin in rat tissues in vivo was investigated. A single ip injection of doxorubicin (30 mg/kg body wt) markedly raised the level of peroxidated lipids measured as TBARS and conjugated dienes in heart and brain membrane preparations. Other tissues, such as retina and liver, did not show any increase of lipid peroxides over control values. Pretreatment of rats with two daily subcutaneous injections of retinol palmitate (0.25 g/kg body wt), for 2 days, before injecting doxorubicin, inhibited peroxidation of heart and brain membrane lipids. The antioxidant action of vitamin A does not appear to be mediated by enhancement of antioxidant enzyme activities committed to detoxify oxygen radicals. Superoxide dismutase and catalase, measured in heart and brain cytosol, were not affected by the vitamin A treatment. On the contrary, a slight increase of catalase activity was observed in heart and brain cytosol from rats that had been treated with doxorubicin. Excess vitamin A may be localized in membranes. Appreciable increase of retinyl esters and retinol was measured in membrane preparations from rats that had been treated with vitamin A, with respect to control animals. Brain and heart membrane preparations from rats receiving vitamin A, assayed in vitro in the presence of an Fe3+ ascorbate induction system, showed a delay at the beginning of the lipid peroxidation and generated lesser amounts of TBARS, with respect to membranes from control rats. Thus, the increase of vitamin A within cell membranes results in an increased resistance of membrane lipids to peroxidation, both endogenously produced and induced in vitro. These results may be consistent with the hypothesis that vitamin A may act as a physiological antioxidant in cell membranes where it is localized.

Animals↗
PubMed1993

[The aneurysmal degeneration of aortocoronary bypasses. A case report].

A 67-year-old man presenting with oppressive atypical chest pain 13 years after aorto-coronary saphenous vein bypass surgery, was found to have a large left anterior mediastinal mass on chest x-rays. Computerized tomography and digital subtraction angiography showed conflicting evidence on the vascular nature of the structure: the suspect diagnosis was of aortic pseudoaneurysm originating in the area of previous aortic cannulation. Selective coronary and bypass angiography showed extreme irregularity and dilatation of the grafts, and revealed the mediastinal mass to be represented by aneurysmal dilatation of the saphenous vein graft to the obtuse marginal coronary artery, partially filled with thrombus. At operation, another smaller aneurysm was found on the right coronary artery graft. Aneurysmal degeneration of vein grafts in the coronary circulation is exceedingly rare, and in only 6 reported cases has such an aneurysm presented as a mediastinal mass. To our knowledge, this is the first case in which an aneurysmal dilatation involved two saphenous vein coronary grafts.

Aged↗
PubMed1992

Lp(a) levels in patients undergoing aorto-coronary bypass surgery.

The aims of this study were to evaluate plasma lipid, apoprotein and Lp(a) levels in patients with severe coronary atherosclerosis undergoing aorto-coronary bypass surgery (BP) and to relate these parameters to the involvement of one or more vessels. Seventy-seven male patients and 77 cardiovascular disease-free controls, matched for sex, age and body weight were studied. Higher triglyceride and apo B levels with lower HDL-cholesterol and apo A-I levels were found in BP patients in comparison with the controls. Lp(a) levels were slightly, but not significantly, increased. Moreover BP patients presented a significantly higher prevalence of HDL-cholesterol levels below 35 mg dl-1 (49.3% vs 22.1%) and Lp(a) levels above 70 mg dl-1 (10.4% vs 1.3%) than the controls. When patients were divided according to the number of coronary vessels involved (one, two or three), no significant difference was found, with a trend to increase in Lp(a) mean levels and in prevalence of Lp(a) levels above 30 and 70 mg dl-1 in more severely diseased patients. These results suggest that patients with severe coronary artery disease undergoing aorto-coronary bypass surgery show low HDL-cholesterol levels with high triglyceride levels. Moreover Lp(a) levels above 70 mg dl-1 are highly associated with severe coronary vessel stenosis.

Aged↗
PubMed1992

[Effect of captopril on human myocardial ACE-inhibition: neurohumoral variations during coronary sinus cardioplegia. Cardioprotective effect during aortocoronary bypass].

UNLABELLED: The present study is aimed at checking effects exerted by captopril on human myocardial ACE system (ACE-T) as well as the role played by tissue ACE-inhibition in reducing reperfusion damage. A human experimental model was used during cardioplegia due to aortocoronary bypass graft (CABG): 54 patients with coronary artery disease affecting 3 vessels having suffered from acute anterior myocardial infarction, homogeneous as far as ejection fraction (35-55%), number of grafts (3), clamping time, age and sex, were randomised in a double blind experiment, and were given captopril or placebo: 4 mg/l captopril were mixed into the cardioplegic solution with blood according to Buckberg, 8 blood samples were obtained from each patient and norepinephrine, epinephrine were assayed using an HPLC technique. Angiotensin 1 was assayed by RIA. CK was assayed as well (U/L). Blood samples were taken during CABG: pre-pump sample; pump sample; pump preclamping sample; coronary sinus sample; warm reperfusion sample; coronary sinus during warm reperfusion; after clamping sample; after cannulation. RESULTS: captopril group (29 patients): angiotensin 1:8.15; 6.9; 7.45; 8.66; 8.93; 8.70; 9.07; 9.40 versus placebo: 7.09; 7.43; 7.80; 9.31; 9.01; 8.35; 8.85; 8.07 mcg (all NS). Noradrenaline: captopril group: 359; 404; 329; 282; 263; 216; 310; 337 versus placebo: 439; 520; 499; 469; 526; 566; 501; 443 pg (p < 0.001). CK, captopril group: 79.9; 95.1; 100.8; 94.3; 104.2; 94.7; 108.4; 108 versus placebo: 76.2; 120.2; 135.5; 203; 225; 272; 247; 228.7 U/L (p < 0.01). Epinephrine values showed no significant difference between the 2 groups. Norepinephrine and CK decrease as well as angiotensin I increase in treated patients as compared to controls suggest some effect exerted by captopril ACE-T and its capability of reducing reperfusion damage and recommend its use for heart protection during CABG.

Aged↗
PubMed1992

[Coronary angioplasty in postinfarct angina].

BACKGROUND: The recurrence of transient myocardial ischemia is a frequent event in the course of acute myocardial infarction. Postinfarction angina develops more frequently after a non-Q wave infarction, and after effective thrombolysis; when uncontrolled by standard medical treatment, it is associated with an increased incidence of unfavorable cardiac events. Therapeutic strategies involve aggressive medical therapy, frequent use of early angiography, and mechanical coronary revascularization with bypass surgery or transluminal coronary angioplasty (PTCA). PATIENTS: We retrospectively examined 68 consecutive patients treated with PTCA for postinfarction angina. Of the whole, 36 (53%) had sustained a non-Q wave infarction; 29 (43%) had been treated with thrombolysis in the acute phase. Ischemia was in the infarction zone in 94% of cases; mean EF was 61.5 +/- 12%, and in 18 cases EF was < 55%. RESULTS: In 7 cases two arteries were dilated. There were no deaths related to the procedure. The overall success rate was 91.2%. Major complications occurred in 2 cases (1 acute occlusion with reinfarction, 1 major dissection requiring emergency surgery). The results are analyzed according to the time interval between index infarction and PTCA. In 28 cases (Group A) PTCA was performed within 30 days due to medically refractory symptomatology; in 40 cases (Group B) PTCA was postponed to beyond 30 days from infarction. In Group A involvement of the left anterior descending coronary artery was more frequent (75% of cases vs 40%; p = 0.009). The success rate in Group A was slightly lower than for Group B (85.7% vs 95%); the incidence of complications was higher (7.1% vs 0%), although not statistically different. At 6 month follow-up a restenosis was found in 10 cases (16% of successful PTCAs, 21% of angiographic controls). CONCLUSIONS: We conclude that for patients with postinfarction angina, selected for a suitable coronary anatomy, PTCA is an effective therapeutic option, with a high success rate, low immediate morbidity, and good mid-term results. The risk of intraprocedural complications appears only slightly higher for patients with unstable symptoms, who undergo PTCA earlier after infarction.

Adult↗
PubMed1987

Oestrogen binding sites in fresh human aortic tissue.

Biopsies of aortic tissue were obtained from patients undergoing heart surgery, and were tested for oestrogen binding sites. Tests were carried out using a 7 + 1-point dextran-coated charcoal method, and receptors were quantified both in the cytoplasmic and in the nuclear fractions using Scatchard plot analyses. Tests yielded positive results in 8 cases out of 13 (cytosol fraction) and in 10 cases out of 13 (nuclear fraction). Receptors showed high affinity for oestrogens, the Kd values ranging from 10(-11) M to 10(-10) M. These findings therefore suggest the occurrence of oestrogen receptors in human blood-vessels.

Aorta↗
PubMed1977

[The biological prostheses of Hancock in our experience of 250 subjects underwent a valvular replacement (author's transl)].

In this study we present the results of 5-years Follow-up of Clinical experimentation with biological prostheses of Hancock in 250 patients underwent a valvular replacement at the Cardiovascular Surgery Institute of Padua University in Verona. We report the immediate and long-term results with the death causes and the complications related above all with thrombo-embolic events. For such complications it was done a comparison relatively to the cases with mitral and aortic prostheses, with the results obtained from another Cardiovascular Surgery Center where are always applied artificial prostheses. From this comparison results that Hancock's biological prostheses has a major tendency to give incidence of embolic in the first months following the valvular replacement, but successively it is clearly to be prefered to artificial prostheses.

Evaluation Studies as Topic↗
PubMed1976

[Use of the femoral artery for chronic hemodialytic treatment].

In 4 patients subjected to periodical haemodialytic treatment a new route of access to the vessels was used; the common femoral artery and the large saphena to the outlet into the femoral vein. All four patients presented serious problems with regard to application of a new shunt in view of the previous reiterated use of the vessels commonly utilized. At the maximum distance of 46 months from implantation, only one of the four by-passes is still in use; 2 were removed for obstruction and the fourth, still operating at the time, was removed for a renal transplant performed on the patient. In view of the frequency of troubles and the use-months of the femoral by-pass compared with the traditional ones, the femoral route of access may be considered favourably when the traditional shunt implantation or fistula creation procedures are precluded.

Adult↗
PubMedDate not supplied

Short- and intermediate-term results of (32)P radioactive beta-emitting stent implantation in patients with coronary artery disease: The Milan Dose-Response Study.

BACKGROUND: Radioactive (32)P beta-emitting stents have been shown to reduce intrastent neointimal hyperplasia in a substantial dose-related manner in the animal model. The aim of this dose-response study was to evaluate, in the clinical setting, the safety and efficacy at 6-month follow-up of this approach to reducing restenosis. METHODS AND RESULTS: A total of 122 (32)P radioactive beta-emitting stents (initially the Palmaz-Schatz and later the BX Isostent) with an activity level of 0.75 to 3.0 microCi (group 1), 3.0 to 6.0 microCi (group 2), and 6.0 to 12.0 microCi (group 3) were implanted in 91 lesions in 82 patients. There were no procedural events. At 6-month follow-up, no deaths had occurred, and only 1 patient had stent thrombosis. Pure intrastent binary restenosis was 16% in group 1, 3% in group 2, and 0% in group 3. However, intralesion restenosis was 52% in group 1, 41% in group 2, and 50% in group 3. CONCLUSIONS: The use of (32)P radioactive beta-emitting stents in patients with CAD is feasible. At 6-month follow-up, intrastent neointimal hyperplasia was reduced in a dose-related manner. However, in the 3 groups, intralesion restenosis was high because of a high late lumen loss in the reference segments at the stent edges, possibly as a result of a low activity level of radiation at the edges of the stent combined with an aggressive approach to stenting. We called this "edge effect" the "candy wrapper."

Analysis of Variance↗