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Biomedical subjects

A Borghi

Publications and source records attributed to A Borghi.

At least 55 records · Page 3Linked to original sources
PubMed1993

Transfemoral closure of patent ductus arteriosus in adult patients.

Patent ductus arteriosus is an uncommon anomaly in adult patients. Surgical closure of patent ductus arteriosus in this age group presents difficult problems to the surgeon. We report our experience of 21 adult patients (19-62 years of age, mean 40 years) who underwent closure of the ductus by transfemoral implantation of a Rashkind double umbrella device. The patients came to light because of atrial fibrillation, congestive heart failure, residual flow after surgical ligation of the duct or because of incidental diagnosis made during physical examination or chest X-ray. In ten patients the pulmonary arterial pressure was normal (systolic pressure < 30 mmHg), in eleven it was elevated (systolic pressure from 30 to 100 mmHg, mean 50 mmHg). In seven patients the duct was clearly calcified and the size of the duct varied from 3 to 9 mm (mean 4.3 mm). In 16 patients the ductus resulted perfectly closed after implantation of the first double umbrella device, two patients had minimal residual aortopulmonary flow, whereas in three patients the residual shunt was significant; two of these also developed haemolysis and went to surgery, in the latter the shunt was completely abolished after implantation of a second 17-mm device 16 months later. In conclusion transcatheter closure of patent ductus arteriosus in adults is feasible, even in the presence of calcifications and/or pulmonary hypertension; taking into account the significant surgical risk, PDA umbrella closure should be considered the first choice procedure in this group of patients.

Adult↗
PubMed1993

Efficacy of a central venous catheter (Hydrocath) loaded with teicoplanin in preventing subcutaneous staphylococcal infection in the mouse.

Segments (1 cm in length) of a central venous catheter (Hydrocath) coated with teicoplanin, or uncoated, were inserted subcutaneously into mice and Staphylococcus aureus or Staphylococcus epidermidis were inoculated nearby. At 24 and 48 h after infection, the mean titre of adherent bacteria (recovered by sonication) for the teicoplanin-coated catheters was less than 10 CFU as compared to more than 10(4) CFU (S. aureus) and 10(3) CFU (S. epidermidis) from the uncoated catheters. In the S. aureus infection, teicoplanin coating also prevented the formation of abscesses which were observed around uncoated catheters.

Animals↗
PubMed1993

[Pulmonary valvuloplasty].

The aim of this study was to present the experience of 2 Institutions (Department of Cardiology in Bergamo and Department of Pediatric Cardiology, Apuano Pediatric Hospital in Massa) in performing the balloon dilatation of the pulmonary valve. From January 1985 to August 1993 the balloon pulmonary valvuloplasty was performed in 220 patients, age ranging from 1 day to 60 years (mean age 5 years), 55 (25%) in the first year of life, 17 (8%) in the first week of life. The systolic gradient across the pulmonary valve fell from 78 +/- 31 mmHg (range 40-160) to 20 +/- 16 mmHg (range 0-70) immediately after the procedure (p < 0.001). In-hospital mortality happened in 3 cases (1.3%); 2 of them were neonates with critical pulmonary stenosis. In 7 cases (3%) the balloon valvuloplasty was repeated afterwards, because of inadequate relief of the gradient after the first dilatation. During the mean follow-up period of 4 years the other 210 patients (95%) did not need any further treatment and remain in stable clinical conditions. The balloon valvuloplasty gives excellent early and intermediate term results and should be considered the first choice procedure in the treatment of pulmonary stenosis at all ages.

Adolescent↗
PubMed1993

Magnetic resonance imaging and different levels of iron overload in chronic liver disease.

The need for accurate and noninvasive evaluation of liver iron stores prompted us to evaluate the reliability of high-field magnetic resonance imaging equipment in liver patients with low or moderate siderosis, given the poor results obtained using systems operating at low field strength in such cases. Twenty patients with sporadic porphyria cutanea tarda and 28 with comparable chronic liver diseases (chronic hepatitis or cirrhosis) and moderate siderosis were compared with 10 patients with idiopathic or secondary hemochromatosis and 10 healthy controls. Plasma iron profile, ferritin concentration and liver iron concentration, determined with atomic absorption spectroscopy, were matched with the magnetic resonance parameters-namely, transverse relaxation time and the signal intensity for a given proton amount, obtained with equipment operating at a field strength of 1.5 T. Hemochromatosis patients with mean liver iron concentrations of 550 mumol/gm dry wt (vs. 10 mumol of controls) exhibited an impressive reduction in the signal intensity with respect to the other three groups, and this reduction prevented any further comparison with the same porphyria cutanea tarda and chronic liver disease groups, whose liver iron level was twice that of the controls. The signal intensity remained almost unchanged in the latter groups, whereas the transverse relaxation time was significantly reduced. Moreover, correlation with liver iron was significantly inverse in the case of the transverse relaxation time (n = 17, r = 0.62, p = 0.008) and direct in the case of the transverse relaxation rate. The transverse relaxation time values returned to normal in five patients who had completed an iron-depletion program.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Determination of the acyl moieties of the antibiotic complex A40926 and their relation with the membrane lipids of the producer strain.

Structures of the fatty acid residues characterizing the various components of A40926 were determined by gas chromatography/mass spectrometry on the methyl esters obtained by methanolysis of the complex. The results confirm the residues previously assigned to Factor A (n-undecanoic acid) and B (10-methyl-undecanoic acid) and establish the residues of Factor A1 (9-methyl-decanoic acid), B1 (n-dodecanoic acid), RS1 (8-methyl-nonanoic acid), RS2 (n-decanoic acid), and RS3 (n-tridecanoic acid). As the Actinomadura species contain in their mycelia large quantities of C15-C17 fatty acid residues as membrane phospholipids, these mycelia were saponified and the fatty acids obtained were analyzed as above. There is a close correlation between the fatty acid content of A40926 complex and that of the longer homologues in the producer mycelia.

Anti-Bacterial Agents↗
PubMed1992

Transient ischaemia refractory to conventional medical treatment in unstable angina: angiographic correlates and prognostic implications.

Complex stenosis morphology is frequently seen in patients with unstable angina. However, its relation to transient myocardial ischaemia and clinical outcome has not been adequately elucidated. We studied 86 patients admitted to the Coronary Care Unit for unstable angina; all patients underwent ECG Holter monitoring during the first 2-4 days, while receiving intensive triple drug treatment. Coronary angiography and subsequent analysis of the ischaemia-related artery were performed within 12 days of admission. Patients were grouped according to their angiographic features: 45 showed complex coronary morphology (CM: 29 eccentric stenosis with irregular borders or overhanging edges; 16 intracoronary thrombus), 11 had documented coronary spasm as well as moderate atherosclerosis (CS), seven had left main coronary artery disease, and the remaining 23 patients showed regular and smooth morphology of coronary stenosis (RM). At admission, transient myocardial ischaemia (TMI) was greater in patients with CM (85 +/- 60 min .24 h-1) than in those with RM or CS (33 +/- 26 min .24 h-1; P less than 0.005). After 3 days of full medical treatment TMI decreased in all groups, but 34/45 patients with CM and 9/34 with RM or CS still showed residual ischaemia (greater than 0 min .24 h-1): 76% vs 26%, P less than 0.02. Follow-up was obtained at hospital discharge and after 1 year in all patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1992

Teicoplanin metabolism in humans.

Teicoplanin, a lipoglycopeptide antibiotic, consists of five major components (A2-1 through A2-5), one hydrolysis component (A3-1), and four minor components (RS-1 through RS-4). All the major components contain an N-acyl-beta-D-glucosamine, but they differ in the lengths and branchings of their acyl-aliphatic chains. Previous studies with radiolabeled teicoplanin in rats and humans have shown that the drug is eliminated by the renal route and that metabolic transformation is very minor, about 5%. A possible metabolic transformation of teicoplanin into A3-1 was also suggested. In the present study in humans, two metabolites (metabolites 1 and 2; 2 to 3% of total teicoplanin) were isolated after intravenous administration of radiolabeled teicoplanin. After purification, their structures were determined by fast atom bombardment mass spectroscopy and 1H nuclear magnetic resonance spectroscopy on the basis of the well-known correlations established in this field, and they were found to be new teicoplaninlike molecules, bearing 8-hydroxydecanoic and 9-hydroxydecanoic acyl moieties. This metabolic transformation is likely due to hydroxylation in the omega-2 and omega-1 positions for metabolites 1 and 2, respectively, of the C-10 linear side chain of component A2-3. This might explain the low extent of metabolism of teicoplanin if we consider that only component A2-3 has a linear chain that is susceptible to such oxidation.

Anti-Bacterial Agents↗
PubMed1992

[Two patients with liver cirrhosis who presented with alpha-fetoprotein values diagnostic of hepatocarcinoma but without evidence of neoplasms].

Two liver cirrhosis (LC) patients with all major risk factors for hepatocellular carcinoma (HCC) had, at presentation, serum alfa-fetoprotein levels (AFP) higher than 500 ng/ml, usually considered diagnostic for HCC. They had elevated serum ALT levels too. No neoplastic liver lesions were detected by imaging techniques in both cases. During the following three months we noted a progressive improvement of clinical conditions with contextual normalization of AFP and ALT values. Therefore we suggest, when AFP is strongly elevated in LC patients but no hepatic lesion is detectable, a check for AFP and ALT time-course, before diagnosis HCC.

Biomarkers, Tumor↗
PubMed1992

[The relationship between anomalies in the autonomous nervous system and left ventricular dysfunction in patients with hypertrophic cardiomyopathy].

This study was undertaken to assess autonomic nervous system (ANS) activity and its relation to left ventricular function in 40 patients (mean age: 41 +/- 17 years) with hypertrophic cardiomyopathy (HC), in sinus rhythm, off-drugs. Patients were grouped according to the results of radionuclide angiography: 26 had an ejection fraction > 50% (Group A), whereas 14 had an ejection fraction < or = 50% (Group B). Evaluation of parasympathetic activity showed abnormalities in: heart rate (HR) response during Valsalva (< or = 1.1) in 2 Group A (8%) and 12 Group B (86%) patients (p < 0.001); HR variability during deep breathing (< or = 10 b/min) in 2 Group A (8%) and 14 Group B (100%) patients (p < 0.001); immediate HR response to standing (30:15 < or = 1.0) in 2 Group A (8%) and 6 Group B (43%) patients (p < 0.025). Assessment of sympathetic activity showed abnormalities in: systolic blood pressure fall to standing (> 20 mmHg) in 2 Group B (14%) patients only (NS); diastolic blood pressure response to handgrip (< 10 mmHg) in 4 Group B (29%) patients only (p < 0.025). Thus, in HC: impaired parasympathetic control is common in those patients showing left ventricular dysfunction; concurrent sympathetic abnormality may also occur in this subgroup of patients; ANS dysfunction seems to be merely an epiphenomenon which marks the severity of left ventricular derangement.

Adult↗
PubMed1992

[The closure with a double-umbrella prosthesis of recanalized ducts after surgical ligation].

Four patients of 5, 27, 27 and 62 years of age, who previously underwent surgical ligation of ductus arteriosus (respectively 3, 17, 19 and 17 years before), came to our observation because of recanalization of the duct. In three cases the duct was an isolated finding, whereas in the oldest patient the duct ligation had been accompanied by implantation of a Starr prosthesis in aortic position. The diagnosis of residual shunt was based on the auscultation of a continuous murmur at the left subclavicular space and on typical signs of patent ductus evidenced by Doppler interrogation. In all cases the diagnosis was confirmed by angiography; the minimal diameter of the ducts varied between 2.5 and 4 mm. Three umbrellas of 17 mm and one of 12 mm diameter were employed for the closure of the residual shunt. The implantation of the double-umbrella device was obtained with the routine transfemoral venous approach. In the youngest patient, in order to facilitate the progression of the transseptal catheter through the duct, it was necessary to create a circuit with the guide wire from the femoral vein to the contralateral femoral artery. In all four patients the shunt was completely abolished. The oldest patient underwent replacement of a malfunctioning aortic prosthesis three days after implantation of the double-umbrella device; the surgical approach was this way significantly simplified. The implantation of a Rashkind double-umbrella device is the method of choice for closure of residual shunts through the duct after surgical ligation.

Adult↗
PubMed1992

[Regional coronary blood flow in patients with acute myocardial infarct treated by systemic fibrinolysis].

Thrombolysis has been reported to restore coronary blood flow in patients with acute myocardial infarction (AMI). However, the relationship between fibrinolytic treatment and evidence of myocardial reperfusion has not been adequately assessed. Accordingly, we measured great cardiac vein blood flow (GCVF:thermodilution) in 12 patients (Group 1) presenting with AMI (chest pain < 4 hours and ST elevation in the anterior leads) before and following i.v. urokinase (UK:2 million U/90 min). Ten patients receiving conventional treatment served as controls (Group 2). UK induced a significant increase of GCVF (from 101 +/- 24 to 164 +/- 42 ml/min, p < 0.001). Maximal increase occurred after 50 +/- 54 min from drug infusion. Conversely, changes in GCVF were not significant in Group 2 (from 103 +/- 35 to 106 +/- 31 ml/min, NS). Following 24 hours changes in GCVF were still consistent only in Group 1 patients. Individual analysis during 24 hours showed marked fluctuations of GCVF peak values in Group 1 patients (62 +/- 43%), but not in Group 2 (29 +/- 21%). Thus, UK induces a marked increase of GCVF in most patients with anterior AMI; such increase suggests that reperfusion occurs early (i.e. within 1 hour) from UK administration. Fluctuations of GCVF during monitoring are magnified by thrombolysis, suggesting intermittent coronary reocclusion in the early hours of AMI.

Blood Flow Velocity↗
PubMed1992

[The clinical implications of the use of an amino acid mixture without tryptophan in liver cirrhosis].

The ingestion of an amino acid mixture lacking tryptophan causes a rapid fall of plasma tryptophan in healthy subjects. This is because amino acids elicit protein synthesis and endogenous tryptophan is incorporated into new proteins. If protein synthesis is the mechanism through which tryptophan-free solution decrease blood tryptophan, it may be interesting to study tryptophan levels after a tryptophan-free mixture in subjects with impaired protein synthesis. In the present paper we show that in 27 cirrhotics the administration of a tryptophan-free solution caused a fall of total plasma tryptophan that began significantly later than in 14 control subjects, the delay being significantly proportional to the severity of the disease. The difference between control and cirrhotic subjects was due to the bound fraction of plasma tryptophan. The diagnostic and clinical usefulness of our findings are discussed.

Amino Acids↗
PubMed1991

Prognostic significance of silent myocardial ischemia in variant angina pectoris.

The present study investigates the prognostic significance of silent myocardial ischemia in variant angina. Forty-eight-hour Holter monitoring and coronary angiography were performed in 54 patients with transient ST elevation and no history of myocardial infarction admitted to the coronary care unit for worsening of symptoms. Coronary artery spasm was documented in most of these patients. Over the subsequent month, 20 patients (group 1) had a major coronary event (2 died, 6 had nonfatal myocardial infarction and 12 had urgent coronary revascularization), and the remaining 34 patients (group 2) had a good clinical outcome. From 2,578 hours of recording, 547 ischemic episodes were identified of which only 9% were associated with angina. The mean daily number of ST elevation in group 1 was similar to that in group 2 (4.8 +/- 5.1 vs 4.1 +/- 4.6; p = not significant). Conversely, the mean daily duration of such ischemic episodes was consistently greater in group 1 than in 2 (79 +/- 36 vs 37 +/- 25 minutes; p less than 0.005). The occurrence of greater than or equal to 1 long-lasting (greater than or equal to 10 minutes) episode of ST elevation was observed in 18 of 20 patients in group 1 (sensitivity 90%), but only in 4 of 34 in group 2 (specificity 88%). Significant coronary atherosclerosis (greater than 50% stenoses) was found at angiography in 18 of 20 patients in group 1, and in 18 of 34 in group 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris, Variant↗
PubMed1991

Angiographic morphology in unstable angina and its relation to transient myocardial ischemia and hospital outcome.

Complex stenosis morphology frequently occurs in patients with unstable angina pectoris. However, its relation to transient myocardial ischemia and hospital outcome has not been ascertained. To address this issue, 88 patients with significant (greater than or equal to 50%) coronary artery disease presenting with angina--new onset (n = 38), worsening (n = 20) or at rest (n = 30)-were studied. Patients with left main artery disease, normal coronary arteries or occlusion of the ischemia-related arteries were not included in the study. Continuous electrocardiographic recordings were obtained during the first 24 hours. Angiography was performed within 1 week from admission. Complex morphology was defined as any stenosis with irregular borders, overhanging edges or intracoronary thrombus. Only data referring to the in-hospital outcome were considered in this study. Adverse end points were sudden death, myocardial infarction and emergency revascularization. Analysis of the angiograms revealed a complex morphology in 58 patients (group 1). The remaining 30 patients served as control subjects (group 2). Thirty-two of the 58 group 1 patients had an unfavorable clinical outcome (positive predictive value, 55%). A similar outcome occurred in only 2 of the 30 group 2 patients (negative predictive value, 93%). Of the 32 group 1 patients who had an unfavorable clinical outcome, 29 had a cumulative duration of transient myocardial ischemia of greater than or equal to 60 minutes per 24 hours. A similar duration of ischemia, however, was observed in another 6 group 1 and in 8 group 2 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina, Unstable↗
PubMed1991

Factors affecting the normal and branched-chain acyl moieties of teicoplanin components produced by Actinoplanes teichomyceticus.

Teicoplanin, a glycopeptide antibiotic produced by Actinoplanes teichomyceticus, comprises five main components, denoted T-A2-1 to T-A2-5, differing in the structure of their acyl side chain, which is linear in T-A2-1 and T-A2-3 and branched in the other components. Production of T-A2-1, characterized by a linear C10:1 acyl moiety, is entirely dependent on the presence of linoleate in the fermentation medium. Addition to the medium of oleic acid esters at 2 g l-1 increases the yields of T-A2-3, characterized by a linear C10:0 acyl chain, about threefold. The antibiotic linear side chains thus appear to originate from C18 unsaturated acid by beta-oxidation degradation. The percentage of T-A2-2, T-A2-4 and T-A2-5, bearing the iso-C10:0, anteiso-C11:0 and iso-C11:0 acyl moieties, respectively, is strongly influenced by the presence in the medium of the amino acids known to be precursors of branched-chain fatty acids. Thus, valine increases the production of T-A2-2 whereas isoleucine or leucine increase the relative yields of T-A2-4 or T-A2-5, respectively. Analysis of the total cell lipids upon addition of the same amino acid shows corresponding increases in the proportion of the iso-C16:0, iso-C15:0 or anteiso-C17:0. A mutant A. teichomyceticus strain, which produces a novel teicoplanin with a linear C9:0 chain, differs from the wild strain in the presence of the linear C17:1 acid in its lipids.(ABSTRACT TRUNCATED AT 250 WORDS)

Acylation↗
PubMed1991

Liver iron overload and desferrioxamine treatment of porphyria cutanea tarda.

The aim of this paper is to evaluate invasive and non-invasive indices of iron store and compare the effectiveness of different ferrodepletive protocols in 150 patients with porphyria cutanea tarda (PCT). Iron removal was performed either by intensive phlebotomy (22 cases) or slow subcutaneous and high intravenous doses of desferrioxamine (18 and 5 cases, respectively), and several laboratory parameters were studied; among these, oligo-elements and urinary porphyrins (detected by HPLC) were taken into account before and after the treatments. Serum iron, transferrin saturation, ferritin (RIA) and nuclear magnetic resonance results were compared with invasive findings in order to detect the metal deposition in liver tissue (atomic absorption concentration, optic or electron-microscopic detection). Liver iron overload was observed in 95% of cases. Full normalization of the disease took place by all the treatments, even if it required slightly more time in the phlebotomy group. We may conclude that ferrodepletive treatments are highly effective in PCT and, considering the fact that siderosis and liver damage always accompany the disease, these treatments are proposed as first choice in such cases.

Bloodletting↗
PubMed1991

Microbial de-mannosylation and mannosylation of teicoplanin derivatives.

The single components of the teicoplanin complex, glycopeptide antibiotics active against Gram-positive bacteria, can be converted in the corresponding de-mannosyl derivatives by cultures of Nocardia orientalis NRRL 2450 or Streptomyces candidus NRRL 3218. Conversely, teicoplanin aglycone and other teicoplanin de-mannosyl derivatives can be converted in the corresponding teicoplanin mannosyl derivatives by cultures of Actinoplanes teichomyceticus ATCC 31121. The biological transformation yields are approximately 40% for de-mannosylation and 90% for mannosylation. The processes allow for the preparation of gram quantities of the de-mannosyl derivatives of teicoplanin and of teicoplanin mannosyl derivatives. De-mannosyl teicoplanin and teicoplanin mannosyl-pseudoaglycone were not amenable to preparation by either acidic or basic chemical hydrolysis.

Actinomycetales↗