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Biomedical subjects

A Colombo

Publications and source records attributed to A Colombo.

At least 55 records · Page 3Linked to original sources
PubMed1990

Cardiac fluoroscopy for the diagnosis of coronary artery disease: a meta analytic review.

To evaluate variability in the reported accuracy of fluoroscopically detected coronary calcific deposits for predicting angiographic coronary disease, we applied meta analysis to 13 consecutively published reports comparing the results of cardiac fluoroscopy with coronary angiography. Population characteristics and technical and methodologic factors were analyzed. Sensitivity and specificity for predicting serious coronary disease compare quite well with those from the literature on the exercise ECG and the exercise thallium scintigram. Sensitivity increases and specificity decreases more significantly with patient age, and sensitivity is paradoxically lower in laboratories testing patients with more severe disease, as well as when 70% rather than 50% diameter narrowing is used to define angiographic disease. Work-up and test review bias were also significantly related to reported accuracy.

Age Factors↗
PubMed1990

Evaluation of atherosclerotic lesions using NMR microimaging.

Magnetic resonance imaging (MRI) has been proposed as a potential tool in the evaluation of atherosclerotic lesions. However, two basic difficulties have to date prevented the full exploitation of the potentials of this technique: the poor spatial resolution of the conventional tomographs and the wide variety of the lesions as well as their intrinsic dishomogeneity. In this study the in vitro morphology of normal and atherosclerotic vascular tissue specimens has been evaluated using a high resolution spectometer equipped with a microimaging device. Morphological features of the vessel walls as small as 10(-1) mm have been detected and the distribution of lipids and of calcified or necrotic regions has been evidenced in atherosclerotic plaques. Different techniques, such as local spectroscopy performed on volumes of 1 mm3 and localized magnetization recovery measurements, have been employed to characterize specific regions of the vessel walls from the chemical and the physical point of view. The good agreement of NMR findings with histological data allows us to conclude that NMR microimaging represents a suitable technique for the in vitro detection and characterization of atheromatous lesions.

Adolescent↗
PubMed1990

Chamber testing of organic emission from building and furnishing materials.

The equipment and the procedure employed for the qualitative and quantitative determination of the volatile organic compounds emitted from samples of building and furnishing materials are described. The equipment includes two small test chambers (0.45 m3), with accurately controlled temperature, relative humidity and air flow rate, and instrumentation for sampling and analysis (Tenax tubes, GC-FID and GC-MS). To find quasi-steady-state emission conditions, the procedure includes the determination of the time profiles of the organic compounds concentration, which develop after the introduction of the samples into the chamber. A best-fitting, double exponential equation is used for this purpose. The procedure has been applied to three materials: particle board with carpet; gypsum board with wallpaper; and plywood with polyurethane lacquer, for which the steady-state emission factors (mg m-2 h-1) of several compounds are given. Many other compounds were identified, but were not quantified. Some comments are given on the health significance of the compounds emitted from the materials when used indoors.

Air Pollutants↗
PubMed1990

Influence of parenteral nutrition on leg nitrogen exchange in injured patients.

Body N balance, 3-methylhistidine (MEH) excretion, amino acid (AA) plasma concentration, and fluxes across the leg were investigated both during fasting and during parenteral nutrition of injured patients in order to better understand protein-sparing mechanisms induced by metabolic support in the whole body and in skeletal muscle. Patients were randomized to receive 15 or 30 kcal/kg.day coupled with 0.30 g of N either with standard or branch-chain (BC)-enriched AA solutions. During fasting, patients were highly catabolic (N balance -14.7 +/- 1.2 g N/m2.day, MEH excretion 422 +/- 25 mumol/m2.day) and showed a high efflux of AA N from the leg (5.08 +/- 2.1 g N/m2.day) without difference between the groups. During treatment, body N balance (-5.55 +/- 0.88, p less than .001) and MEH excretion (284 +/- 20, p less than .001) were significantly reduced without difference among the groups; also, AA N leg efflux (2.64 +/- 0.47, p less than .001) was reduced. Moreover, considering the effect of calorie load, patients receiving 30 kcal/kg.day showed a lower efflux of total AA N and of some AA considered as markers of muscle protein catabolism, such as phe, lys, met, and glu. The main difference between solutions was in the efflux of BCAA; particularly, val and leu efflux was turned into uptake in the BCAA group. No significant difference among the groups was found in N balance and MEH excretion during treatment. In brief, muscle catabolism was reduced in an amount dependent on glucose and insulin load, but it was not influenced by BCAA supply. Whole body net protein catabolism was reduced through different mechanisms, either an increased visceral N retention or a decreased muscle N loss. However, muscle N loss was never abolished even in the high calorie groups.

Adolescent↗
PubMed1990

Heparin and secondary prevention of acute myocardial infarction.

Patients surviving acute myocardial infarction (AMI) may experience several clinical events (reinfarction, congestive heart failure, sudden death) still responsible for high mortality rates. AMI early complicated by residual angina, left ventricular dysfunction, or malignant arrhythmias has a worse prognosis. Secondary prevention of myocardial infarction and death has been the end point of many clinical trials in the past two decades. It is well known that beta blockers prevent sudden death if administered chronically after AMI. Meta-analysis of controlled randomized trials demonstrated a significant reduction in reinfarction and vascular death with long-term antiplatelet treatment. Oral anticoagulants prevent fatal and non-fatal reinfarction and show a trend towards lower mortality rates, though treated patients have a higher incidence of haemorrhagic events, particularly stroke. Early administration of heparin gave contradictory results on short-term prevention of myocardial infarction and death after AMI. Data on long-term heparin therapy point out a significant reduction in recurrent AMI and a trend towards a decrease in general mortality.

Administration, Oral↗
PubMed1990

[Coronary angioplasty in patients with compromised left ventricular function].

One thousand one hundred and thirty-two percutaneous transluminal coronary angioplasties have been performed at Centro Cuore Columbus in Milan between January 1987 and September 1989. The whole population was divided into two groups: Group A (90 patients with ejection fraction less than or equal to 0.40); Group B (678 patients with ejection fraction greater than 0.40. Mean ejection fraction in Group A (0.35) was significantly lower (p less than 0.0001) than in Group B (0.56). In each group three subsets were identified: subgroup 1: total obstruction of two major epicardial vessels plus severe stenosis of the patent one; subgroup 2: total obstruction of one vessel plus severe stenosis on a different remote one; subgroup 3: all patent vessels with one or more severe stenoses on one or all. We attempted percutaneous transluminal coronary angioplasties on 923 stenosed and 161 totally obstructed vessels, with a primary success of 95 and 56% respectively. We experienced 36 major complications (7 deaths, 10 acute myocardial infarctions, 19 emergency aortocoronary bypasses in 21 patients (2.7% of the whole population). Subgroup A1 (7 patients with ejection fraction less than or equal to 0.40 and attempted percutaneous transluminal coronary angioplasties on the sole patent vessel) showed the lowest success rate (44%) and the highest complication rate: 3 deaths (42.8%); 1 acute myocardial infarction (14.2%); 3 emergency aorto-coronary by-pass (42.8%). The 83 patients in group A2 and A3, with reduced ejection fraction, did not have significantly higher complication rate than all group B patients, with normal ejection fraction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Plasma beta-endorphin and beta-lipotropin in congestive heart failure in man.

Beta-endorphin and beta-lipotropin plasma concentrations were evaluated in 24 patients with congestive heart failure (CHF) (10 patients had chronic CHF and 14 an acute episode superimposing on chronic CHF), and in 35 age matched controls. Beta-endorphin and beta-lipotropin were significantly lower (P less than 0.005 and P less than 0.001 respectively) in patients with CHF than in controls. A significant decrease of both peptides vs controls was observed also in the two subgroups of patients, with chronic and acute CHF, without statistical differences between the subgroups. Beta-endorphin and beta-lipotropin showed a close and significant correlation (r = 0.88, P less than 0.001) amongst the whole series of patients as well as in both subgroups with chronic and acute CHF. In consideration of the long duration of the disease the decreased concentrations of beta-endorphin and beta-lipotropin can be considered to be due to a depletion of the releasable pool of the peptides, as it was previously shown for chronic stress.

Acute Disease↗
PubMed1990

[Radiotherapy plus a combination of cisplatin and 5-fluorouracil for locally advanced head and neck neoplasms. Study of feasibility and preliminary results].

In March 1989 we started a feasibility study of combined radio-chemotherapy in patients with locally-advanced head and neck cancer. The first phase of treatment consisted of conventional radiotherapy (2 Gy/day, 5 days/week for a total dose of 70 Gy to primary tumor and +/- 50 Gy to nodes) and cisplatinum (20 mg/m2, i.v., for 4 days) +5FU (200 mg/m2, i.v., for 4 days) every 4th week, during radiant sessions. The second phase of treatment was started about one month after the end of simultaneous chemotherapy and radiotherapy: patients in complete remission received 1 more cycle of chemotherapy, as consolidation, while patients in partial remission received two more cycles of chemotherapy. Non-responding patients received no more chemotherapy. During the second phase the days of cisplatinum and 5FU were 5. Up to April 1990, 17 patients have been included in the study. They were stage III (64%) and IV (36%). The mean administered dose of radiotherapy was 66 Gy (range: 60-70 Gy) to primary tumor and 60 Gy (range: 40-70 Gy) to nodes. The total number of chemotherapy cycles administered during radiant sessions was 37, the mean number of cycles was 2 (range: 1-3), with 100% dose percentage. The interval between cycles was 3 weeks in 84% of patients. The relationship between number of cycles administered and planned cycle was 37/39 (feasibility: 95%). Acceptability was 100% (no patient refused the treatment). Feasibility of the second phase was 77% and acceptability 90% (1 patient refused the treatment). Toxicity was moderate during the first and the second phases. After the first phase 14/15 evaluable patients (92%) had major response (complete remission: 46%). After the second phase 10/10 evaluable patients had a complete remission. In conclusion, this combined treatment is very easy to administer, and very well accepted. Moreover, it yields a high number of objective responses.

Aged↗
PubMed1990

[Rupture of anterior descending artery during coronary angioplasty: benign course and spontaneous repair. Description of a case].

The authors describe a case report on the rupture of the distal left anterior descending artery during PTCA. This complication gave rise to a fistula between the ruptured distal anterior descending and the right ventricular cavity. The patient was asymptomatic and was treated conservatively. The coronary arteriogram at six months follow-up showed the closure of the fistula with patency of the vessel up to that segment.

Angioplasty, Balloon, Coronary↗
PubMed1989

Exercise-induced ST segment depression in the diagnosis of multivessel coronary disease: a meta analysis.

To evaluate the variability in the reported accuracy of the exercise electrocardiogram (ECG) for predicting severe coronary disease, meta analysis was applied to 60 consecutively published reports comparing exercise-induced ST depression with coronary angiographic findings. The 60 reports included 62 distinct study groups comprising 12,030 patients who underwent both tests. Both technical and methodologic factors were analyzed. Wide variability in sensitivity and specificity was found (mean sensitivity 81% [range 40% to 100%, SD 12%]; mean specificity 66% [range 17% to 100%, SD 16%]). All three variables found to be significantly and independently related to sensitivity were methodologic (the exclusion of patients with right bundle branch block, the comparison with another exercise test thought to be superior in accuracy and the exclusion of patients taking digitalis). Exclusion of patients with right bundle branch block and comparison with a "better" exercise test were both significantly associated with sensitivity for the prediction of triple vessel or left main coronary artery disease. Adjustment of exercise-induced ECG changes for changes in heart rate was strongly associated with the specificity for critical disease (partial R2 = 0.436, p = 0.0001).

Coronary Angiography↗
PubMed1989

CT in established Volkmann's contracture in forearm muscles.

Differential diagnosis between true and pseudo-Volkmann's contracture should not be based on clinical grounds alone, because clinical data are often insufficient in determining the severity and the extent of muscle damage. CT has been utilised in 11 cases where a flexion contracture of the forearm muscles was present and corresponded closely with the surgical findings. True and pseudo-Volkmann's contracture can thus be distinguished and the severity and extent of the muscle damage determined.

Adolescent↗
PubMed1989

Chronic gastric torsion in infancy: a revisited diagnosis.

Twenty out of 108 infants with vomiting, who underwent an upper gastrointestinal X-ray study during a period of 2 years, showed a peculiar shape and position of the stomach already described as chronic gastric torsion. We examined clinical, radiologic and laboratory findings of these 20 infants. Our results showed that chronic gastric torsion is frequently associated with gastroesophageal reflux and has a wide spectrum of symptoms, complications and nutritional abnormalities.

Female↗
PubMed1989

Acute nonlymphocytic leukemia: evidence of clonogenic cells in peripheral blood in early complete remission.

We describe a patient with acute nonlymphocytic leukemia in whom chromosomal analysis showed a 8,21(q22;q22) translocation and who entered complete remission after one course of chemotherapy. During the post-chemotherapy aplastic phase blood-derived hemopoietic circulating stem cells were collected by continuous flow aphereses. Chromosomal analysis on the collected cells and on colonies (CFU-GM grown in agar) showed the same anomaly as was present at diagnosis in about 30% of those analyzed. This confirms the persistence of the malignant clone in the early phase of the clinical remission in acute nonlymphocytic leukemia.

Adult↗
PubMed1989

Exercise-induced ST depression in the diagnosis of coronary artery disease. A meta-analysis.

To evaluate the variability in the reported diagnostic accuracy of the exercise electrocardiogram, we applied meta-analysis to 147 consecutively published reports comparing exercise-induced ST depression with coronary angiography. These reports involved 24,074 patients who underwent both tests. Population characteristics and technical and methodologic factors, including publication year, number of electrocardiographic leads, exercise protocol, use of hyperventilation, definition of an abnormal ST response, exclusion of certain subgroups, and blinding of test interpretation were analyzed. Wide variability in sensitivity and specificity was found (mean sensitivity, 68%; range, 23-100%; SD, 16%; and mean specificity, 77%; range, 17-100%; SD, 17%). The four study characteristics found to be significantly and independently related to sensitivity were the treatment of equivocal test results, comparison with a "better" test such as thallium scintigraphy, exclusion of patients on digitalis, and publication year. The four variables found to be significantly and independently related to specificity were the treatment of upsloping ST depressions, the exclusion of subjects with prior infarction or left bundle branch block, and the use of preexercise hyperventilation. Stepwise linear regression explained less than 35% of the variance in sensitivities and specificities reported in the 147 publications. There is wide variability in the reported accuracy of the exercise electrocardiogram. This variability is not explained by information reported in the medical literature.

Coronary Disease↗
PubMed1989

[Effects of various caloric intakes on nitrogen metabolism of the body, the muscles and the viscera during total parenteral nutrition with aminoacidic solution enriched with branched-chain amino acids].

Nitrogen metabolism was studied in ten injured/septic patients by means of a two compartment model, differentiating muscle from non muscle (central) tissue. During fasting muscle tissue loses a consistent amount of aminoacids which is retained in part by central tissue, giving rise to a positive nitrogen balance, whilst three methyl histidine and body nitrogen output are elevated. Total parenteral nutrition (glucose 15 kcal kg-1 day-1, nitrogen 0.30 g kg-1 die-1) improved body nitrogen balance and three methyl histidine excretion, but did not affect significantly either muscle or central nitrogen balance. Increasing caloric support to 30 kcal kg-1 day-1 did not showed any further effect on body nitrogen balance and three methyl histidine, while it improved significantly vs basal muscle nitrogen balance, but did not affect central nitrogen balance.

Amino Acids, Branched-Chain↗
PubMed1989

Retrieval technique of a PTCA guidewire.

A report is made of a case study where a non-surgical technique was used to remove a broken floppy percutaneous transluminal coronary angioplasty (PTCA) guidewire. The technique involved the use of a "lasso" to successfully retrieve the broken wire from the left main artery and into the aorta.

Adult↗