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Biomedical subjects

V Bianchi

Publications and source records attributed to V Bianchi.

At least 73 records · Page 4Linked to original sources
PubMed1992

[Assessment of knowledge of cardiopulmonary resuscitation].

The knowledge about standardized CPR of 41 physicians and 30 7th grade medical students was evaluated using a written multiple choice test. Results showed a severe lack of information about CPR in both groups; the test was approved by 39% of physicians and 10% of medical students. Among physicians, the lower achievements were obtained by traumatologists and the best by internists. The basic level of questions were approved by 63% of physicians and 43% of medical students. The principal deficiencies were on pharmacological management and CPR in trauma. It is concluded that education programs on CPR, similar to those given by the American Heart Association, are urgently needed among physicians and medical students.

Cardiopulmonary Resuscitation↗
PubMed1991

Prevalence and prognostic significance of silent myocardial ischaemia detected by exercise test and continuous ECG monitoring after acute myocardial infarction.

The incidence and prognostic significance of silent myocardial ischaemia in 165 patients who survived a first acute myocardial infarction were assessed by means of maximal exercise stress test and 24 h continuous ECG monitoring performed before discharge. During the 1 year follow-up period 10 cardiac deaths occurred; moreover seven patients suffered a fatal myocardial re-infarction and 14 developed unstable angina. Cardiac death occurred in five of 40 patients (12.5%) with ST segment depression on stress test by in only three of 117 (2.6%) without ST segment changes (P less than 0.01). One-hundred-and-three of 117 patients (88.0%) without angina or ST segment depression on stress testing survived 1 year without cardiac events, compared with 24 of 40 patients (60.0%) with ST segment depression whether or not associated with angina (P less than 0.001). Cardiac death occurred in five of 25 patients (20.0%) with ST segment depression on continuous ECG monitoring, compared with five of 140 (3.6%) without (P less than 0.01). One-hundred-and-seventeen out of 140 patients (83.6%) without angina or ST segment depression survived 1 year follow-up without cardiac events, compared with 13 of 25 (52.0%) with ST segment depression with or without angina (P less than 0.01). Classifying patients in a 2 x 5 contingency table according to the occurrence of ST segment depression on exercise testing and/or ECG ambulatory monitoring, the Yates corrected chi-square test showed a significant pattern when cardiac deaths and cardiac events were considered together (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

A new insight into the histogenesis of 'mesodermomas'--malignant mesotheliomas.

A myogenic phenotype was induced in cultures of human mesothelial cells treated for 72 h with atrazine, a triazine derivative. Immunoreactivity for both myosin and myoglobin was detected in a large number of these cells, irrespective of their polygonal or spindle morphology, whereas no expression of desmin was observed. These findings support the embryological identity of mesothelium and mesoderm, the former being, in the post-embryonic stage, potentially capable of differentiation along the same lineages which the latter normally displays during embryogenesis. In the light of this concept it can be assumed that primary malignancies arising from the mesothelium have the competence to express the pluripotent nature of embryonic mesoderm, and hence the term mesodermoma is appropriate for this group of tumours, including mesotheliomas in a classical sense. A postulated mechanism for the phenotypic change of mesothelial cells is also outlined, involving atrazine conversion to 5-aza-chloro-cytidine, a probable DNA hypomethylating and gene activating agent, like its analogue 5-azacytidine.

Atrazine↗
PubMed1991

[Cardiac changes induced by deconditioning in athletes: an echocardiographic and electrocardiographic study].

The relationships between echocardiographic and electrocardiographic variations and the sensibility of three different electrocardiographic criteria of left ventricular (LV) hypertrophy were assessed during deconditioning in 18 top-level oarsmen (mean age 23 +/- 4 years). After seven months of training and on the 7th and 21st deconditioning days the oarsmen underwent clinical examination, electrocardiogram (ECG) and echocardiogram with Doppler evaluation. The following ECG measurements were obtained: heart rate (HR), QTc, QRS and T waves axes, QRS and T wave angular gradients, R, S and T wave amplitude and T wave area. Moreover, the sums of S wave in lead V1 plus R wave in lead V5 or V6, of S wave in lead V1 or V2 plus R wave in lead V5 or V6, and of R wave in lead aVL plus S wave in lead V3 were calculated as indices of left ventricular hypertrophy. The following echocardiographic parameters were also analyzed: intraventricular septal (IVST) and posterior wall thickness (PWT), LV internal diameter (LVID), left ventricular mass (LVM) and volumes, LV endocardial/epicardial diastolic surface area ratio, peak systolic meridional wall stress (PSS), end-systolic stress (ESS) and mean systolic wall stress (MWSI), LV ejection fraction (EF) and total peripheral resistances (TPR); early (E) and late (A) transmitral peak flow velocity, E/A ratio. Systolic blood pressure was reduced after 3 deconditioning weeks, while diastolic blood pressure and HR were unchanged. Left ventricular mass and end-systolic volume were reduced after 1 week, while LV end-diastolic volume only after 3 weeks; therefore, EF improved at the end of the first week when TPR were lower. End-systolic stress always remained unchanged; PSS increased at 1 week and then returned to previous values. In addition, the endocardial-epicardial area ratio increased after 1 week and then returned to starting values after 3 weeks. Doppler parameters were in the normal range and remained unchanged during the study. Amplitudes of R wave in aVL, V5, V6 and of S wave in V2 did not change, while S wave amplitude in V1 and V3 decreased after three weeks and one week, respectively. The most sensible criterion for LV hypertrophy was the sum of S wave in V1 or V2 plus R wave in V5 or V6 (range from 33.3% to 22.2%); the sum of S in V1 plus R in V5 or V6 performed better than the sum of R in aVL plus S in V3.(ABSTRACT TRUNCATED AT 400 WORDS)

Adaptation, Physiological↗
PubMed1991

[Influence of age on the short- and medium-term prognosis in patients with acute myocardial infarct].

Elderly patients with acute myocardial infarction (AMI) have a higher subsequent mortality than younger ones, yet the reasons for this adverse prognosis are poorly understood. We compared the clinical course and the prognosis of 163 patients aged 40 to 69 years with 112 patients older than 70 years. During hospitalization period 15.9% of younger and 37.5% of older patients died; at 1 year follow-up the cardiac mortality rate was 8.7% in younger and 12.9% in older patients. In elderly patients a greater prevalence of female gender, diabetes mellitus, anterior myocardial infarction, atrial fibrillation and a greater incidence of heart failure and shock were observed. Multivariate stepwise analysis identified shock and heart rate greater than or equal to 90 bpm at the time of admission as the most important prognostic variables for in-hospital mortality in both groups; heart failure (Killip class II and III) was significant in younger patients, while non Q wave myocardial infarction correlated with a better prognosis in elderly. In elderly patients who survived AMI, predischarge Holter monitoring showed higher frequency and complexity of ventricular arrhythmias, and radionuclide angiography lower left ventricular ejection fraction (E.F.) values. In these patients no difference was found in E.F. values despite myocardial infarction sites. At 1 year follow-up E.F. less than 40% and ventricular arrhythmias (3-4 Moss grading system) were significantly related to prognosis in younger patients, while E.F. less than 40% and clinical signs of heart failure in elderly. Therefore, low E.F. and heart failure account for a worse prognosis in elderly patients, while ventricular arrhythmias in younger ones. The results of this study support aggressive management even in elderly patients following AMI to preserve left ventricular function. In elderly patients a large use of antiarrhythmic drugs is not recommended because of low prognostic value of ventricular arrhythmias.

Adult↗
PubMed1990

[The clinical characterization and prognostic significance of episodes of transient myocardial ischemia in patients with a recent myocardial infarct].

The incidence and prognostic significance of silent myocardial ischemia were assessed in 175 patients who survived a first acute myocardial infarction (AMI). This was done by means of a 24-hour continuous ECG monitoring which was performed before discharge. Twenty-six out of 175 patients (14.8%) showed one episode or more of S-T segment depression; 19 of these reported no pain at all while the other 7 reported both painful and painless episodes. A total of 65 ischemic episodes were registered; of these 53 (81.5%) were painless and 12 (18.5%) were painful. No difference in the duration of ischemic episodes or in heart rate at the onset of S-T segment depression was detected for painless or painful episodes. The S-T segment depression episodes showed a peak in the morning but were higher in the afternoon and this circadian pattern was statistically significant both with regard to duration (p less than 0.05) and to the number of episodes (p less than 0.05). Cardiac death occurred in 5 of the 26 patients (19.2%) with S-T segment depression during continuous ECG monitoring, and in 5 of the 149 (3.4%) without S-T segment depression (p less than 0.01). In patients with ischemia duration greater than 60 min/24 hours, the mortality rate was higher (p less than 0.05). No cardiac events (unstable angina, non-fatal re-infarction, balloon angioplasty and/or coronary by-pass) occurred in 117 out of 149 patients (78.5%) without ST-segment depression, while these events were observed in 13 out of the 26 patients (50%) with ischemic episodes during Holter monitoring (p less than 0.01). Sensitivity and specificity of S-T segment depression was respectively 29.3 and 89.5% for cardiac death and cardiac events considered together.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary Disease↗
PubMed1990

[A Doppler echocardiographic study of normal and dysfunctioning Carpentier-Edwards bioprostheses].

The aim of this study was to delineate the Doppler echocardiographic characteristics of normal and dysfunctioning Carpentier-Edwards bioprostheses. Echocardiographic and Doppler studies were performed on 61 mitral and 41 aortic valves; by means of on clinical evaluation, 15 mitral and 12 aortic valves were considered to be abnormally functioning. The maximum velocity (Vmax) of diastolic left ventricular inflow, pressure half-time and valve orifice area were assessed for prostheses in mitral position, while the maximum velocity (Vmax) of transaortic flow was calculated for prostheses in aortic position. Moreover, the quantitative assessment of mitral and/or aortic regurgitation was performed using the mapping technique with pulsed Doppler wave mode. Normally functioning mitral prostheses were characterized by Vmax less than 2.20 m/s and pressure half-time less than 164 ms; furthermore, mean values of Vmax and pressure half-time were significantly lower in normal than in dysfunctioning prostheses (1.70 +/- 0.33 vs 2.09 +/- 0.52 m/s; p less than 0.01 and 96.14 +/- 29.76 vs 147.87 +/- 57.41 ms; p less than 0.01 respectively). All dysfunctioning mitral valves were characterized by regurgitation graded as severe in 8 cases and moderate in 7 but only 40 and 20% of these presented respectively Vmax and pressure half-time values which were higher than those of normally functioning valves (2.20 m/s and 164 ms respectively); no pure stenosis was found. In the aortic position, normally functioning prostheses were characterized by Vmax less than 3.10 m/s. Furthermore, mean Vmax values were lower in normal than in dysfunctioning prostheses (2.55 +/- 0.53 vs 3.18 +/- 0.80; p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Valve↗
PubMed1989

Plasma membrane damage detected by nucleic acid leakage.

Among the indicators of membrane damage, the leakage of intracellular components into the medium is the most directly related to the perturbations of the membrane molecular organization. The extent of the damage can be evaluated from the size of the released components. We have designed a protocol for the detection of membrane leakage based on the preincubation of cells with tritiated adenine for 24 h, followed by a 24-h chase in nonradioactive medium. The treatment takes place when the distribution of the precursor among its end products has reached the plateau, and thus the differences of radioactivity in the fractions obtained from the control and treated cultures (medium, nucleotide pool, RNA, DNA) correspond to actual quantitative variations induced by the test chemical. Aliquots of the medium are processed to determine which percentage of the released material is macromolecular, in order to distinguish between mild and severe membrane damage. The origin of the extracellular radioactivity can be recognized from the variations of RNA counts in the treated cells. DNA radioactivity is used to evaluate the number of cells that remain attached to the plates in the different conditions of treatment. By this means, generalized permeabilization of membranes to macromolecules is distinguished from complete solubilization of only a subpopulation of cells. We present some examples of application of the protocol with detergents (LAS, SDS, Triton X-100) and with Cr(VI), which damages cell membranes by a different mechanism of action.

Adenine↗
PubMed1989

[Ischemic coronary artery disease in menopause].

Women show a lower incidence of Coronary Artery Disease (CAD) and probably a better prognosis than men. However better survival rate of women tended to be obscured because they were more likely to have histories of hypertension and diabetes and to be older than men. In this paper, incidence, clinical presentation, and prognosis of CAD in women are examined. Furthermore the conflicting reports concerning the effect of estrogen use on morbidity from CAD are reported. Finally the syndrome of angina with a normal coronary arteriogram, sometimes referred to as "Syndrome X" is analyzed.

Angina Pectoris↗
PubMed1989

[Traumatic laceration of facial nerve and Stenone duct. A clinical case].

After a brief review of the main operating techniques employed in the reconstruction of the facial nerve and Stenone's duct lacerated by trauma, a clinical case in which the two lesions are associated is reported. Suture of the lacerated nervous branches and attachment of the salivary fistula to the oral mucosa using a silicon drainage applied for a few days permitted functional recovery of neuronal activity and salivation.

Adolescent↗
PubMed1988

Review of genetic effects and mechanisms of action of chromium compounds.

When similar experimental conditions are adopted to test Cr(VI) and Cr(III) genotoxicity, only the former gives positive results, and Cr(III) is scored as genetically inert. Since Cr(III) seems to be the main final genotoxic agent inside the cell, the observed difference in genetic activity of the two oxidation states can be referred to the easy transport of Cr(VI) across the plasma membrane, as opposed to the lack of membrane carriers for Cr(III). If the experimental design is adjusted to Cr(III) properties, Cr(III) appears (mildly) genotoxic. The accepted inactivity of Cr(III) on whole cells is thus questionable and the environmental impact of Cr(III) accumulation is worth reconsidering.

Animals↗
PubMed1988

[Different modalities of classification and prognostic significance of ventricular arrhythmias after acute myocardial infarct. Prospective study].

In our study we compared the prognostic significance of clinical variables, laboratory results and different classification models of ventricular ectopic beats recorded by means of a pre-discharge 24 hour ambulatory electrocardiographic monitoring, in 210 survivors of acute myocardial infarction. In addition a full multivariate analysis of the factors affecting survival time was carried out using Cox's proportional hazards (multiple) regression model. Multivariate stepwise discriminant analysis identified hypertension, congestive heart failure assessed by Killip class, and the grading system for ventricular arrhythmias as the most important prognostic variables. When Moss grading system for ventricular arrhythmias was used, the relative risk was a superior as heavy Moss grading system (Moss 2 vs Moss 1 and Moss 3-4 vs Moss 1, relative risk = 1.2 and 3.6 total death, respectively). Furthermore, the hazard ratio of Moss grading system was higher utilizing as comparison patients without ventricular ectopic beats (relative risk = 1.7 for Moss 2 and 5.3 for Moss 3-4) than patients with ventricular ectopic beats less than one/hour (relative risk = 1.2 for Moss 2 and 3.7 for Moss 3-4). Thus, in survivors of acute myocardial infarction, a rational and useful ventricular ectopic beats categorization includes both frequency and the presence or absence of malignant characteristics.

Adult↗
PubMed1987

Continuous subcutaneous insulin infusion (CSII) in pregnant diabetic patients.

The efficacy of the insulin infusion pump (CSII) in pregnancy was examined in 12 diabetic patients and compared with intermittent insulin therapy (IIT). In patients poorly controlled on IIT constant and rapid equilibrium was achieved with CSII (mean of glucose levels: CSII versus IIT = 84 versus 137 mg/dl; S.D. = 36 versus 63 mg/dl; mean amplitude of glycemic excursion (MAGE) = 65 versus 112 mg/dl. In patients well controlled on IIT, CSII led to a reduction in the variation of glucose excursions (S.D. = 29 versus 36 mg/dl; MAGE = 48 versus 76 mg/dl). CSII generally produced a reduction of 20-37 per cent of daily insulin dose (in three cases there was an increase of dose with the achievement of glycemic control). Furthermore in CSII treated-patients amniotic glucose, insulin and C-peptide concentrations were found to be in the normal range (22.1 +/- 10.1 mg/dl; 5.2 +/- 2.7 microU/ml; 1.25 +/- 0.71 ng/ml, respectively). All infants were born at or near-term, had no macrosomia or neonatal problems. It is concluded that CSII is a highly efficient way to achieve normal glucose levels in pregnancy, not only in type I, but also in type II or gestational diabetes.

Adult↗
PubMed1987

Regulation of pyrimidine deoxyribonucleotide metabolism by substrate cycles in dCMP deaminase-deficient V79 hamster cells.

A mutant V79 hamster fibroblast cell line lacking the enzyme dCMP deaminase was used to study the regulation of deoxynucleoside triphosphate pools by substrate cycles between pyrimidine deoxyribosides and their 5'-phosphates. Such cycles were suggested earlier to set the rates of cellular import and export of deoxyribosides, thereby influencing pool sizes (V. Bianchi, E. Pontis, and P. Reichard, Proc. Natl. Acad. Sci. USA 83:986-990, 1986). While normal V79 cells derived more than 80% of their dTTP from CDP reduction via deamination of dCMP, the mutant cells had to rely completely on UDP reduction for de novo synthesis of dTTP, which became limiting for DNA synthesis. Because of the allosteric properties of ribonucleotide reductase, CDP reduction was not diminished, leading to a large expansion of the dCTP pool. The increase of this pool was kept in check by a shift in the balance of the deoxycytidine/dCMP cycle towards the deoxynucleoside, leading to massive excretion of deoxycytidine. In contrast, the balance of the deoxyuridine/dUMP cycle was shifted towards the nucleotide, facilitating import of extracellular deoxynucleosides.

Animals↗
PubMed1986

Changes of deoxyribonucleoside triphosphate pools induced by hydroxyurea and their relation to DNA synthesis.

Hydroxyurea inactivates ribonucleotide reductase from mammalian cells and thereby depletes them of the deoxynucleoside triphosphates required for DNA replication. In cultures of exponentially growing 3T6 cells, with 60-70% of the cells in S-phase, 3 mM hydroxyurea rapidly stopped ribonucleotide reduction and DNA synthesis (incorporation of labeled thymidine). The pool of deoxyadenosine triphosphate (dATP) decreased in size primarily, but also the pools of the triphosphates of deoxyguanosine and deoxycytidine (dCTP) were depleted. Paradoxically, the pool of thymidine triphosphate increased. After addition of hydroxyurea this pool was fed by a net influx and phosphorylation of deoxyuridine from the medium and by deamination of intracellular dCTP. An influx of deoxycytidine from the medium contributed to the maintenance of intracellular dCTP. 10 min after addition of hydroxyurea, DNA synthesis appeared to be completely blocked even though the dATP pool was only moderately decreased. As possible explanations for this discrepancy, we discuss compartmentation of pools and/or vulnerability of newly formed DNA strands to nuclease action and pyrophosphorolysis.

Cells, Cultured↗
PubMed1986

Interrelations between substrate cycles and de novo synthesis of pyrimidine deoxyribonucleoside triphosphates in 3T6 cells.

Degradation of pyrimidine deoxyribonucleoside triphosphates plays a major role in the regulation of their pool sizes in 3T6 cells. During normal growth, these cells excrete deoxyribonucleosides (mostly deoxyuridine) into the medium. When DNA strand elongation is inhibited, de novo synthesis of dCTP and dTTP continues, followed by degradation of the deoxyribonucleotides. We now demonstrate that inhibition of de novo synthesis with hydroxyurea stops degradation of deoxyribonucleotides. We now demonstrate that inhibition of de novo synthesis with hydroxyurea stops degradation of deoxyribonucleotides and leads to an influx of deoxyuridine from the medium. This effect appears to be caused by a large drop in the size of the intracellular dUMP pool. We propose that substrate cycles, involving phosphorylation of deoxyribonucleosides by kinases and dephosphorylation of deoxyribonucleoside 5'-phosphates by a nucleotidase, participate in the regulation of the size of pyrimidine deoxyribonucleoside triphosphate pools by directing the flow of deoxyribonucleosides across the cell membrane. While kinases are regulated mainly by allosteric effects, the activity of the nucleotidase appears to be regulated by substrate concentration.

Animals↗
PubMed1986

Continuous subcutaneous insulin infusion (CSII) in pregnant diabetic women.

Insulin infusion pump treatment (CSII) in pregnancy was compared with conventional therapy (IIT) in 12 pregnant diabetic women. In patients poorly controlled on IIT a plasma glucose equilibrium was achieved with CSII (mean of: glucose levels = 84 vs 137 mg/dl; SD = 36 vs 63 mg/dl; MAGE = 65 vs 112 mg/dl). In patients well controlled on IIT, CSII led to a reduction in the variation of glucose excursions (SD = 29 vs 36 mg/dl; MAGE = 48 vs 76 mg/dl). CSII generally led to a reduction of 20-37% of daily insulin dose but in 3 cases there was an increase of dose with the achievement of glycaemic control. A significant relation between bolus/basal ratio of insulin daily dose and the quality of glycaemic control was also found during CSII. All infants were born at or near to term and none were macrosomic or had neonatal complications. It is concluded that CSII is highly efficient in pregnancy not only in type I but also in type II or gestational diabetes.

Adult↗