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Biomedical subjects

G Martini

Publications and source records attributed to G Martini.

At least 73 records · Page 4Linked to original sources
PubMed1997

Coronary stenting in 1000 consecutive patients. Long-term clinical and angiographic results.

Coronary stent implantation has become an accepted treatment for selected patients but the long-term outcome after stent implantation has not been investigated in a large unselected population. This study reports clinical and angiographic results after coronary stent implantation in a consecutive group of 1000 patients treated between November 1989 and June 1994. A total of 2012 stents were implanted in 1216 lesions. The anticoagulation regimen after successful stenting was abolished in the last 499 patients, treated with aspirin and ticlopidina. Complex lesions (type B2, type C lesions and chronic total occlusions) were less frequent in the group with anticoagulation (67%, 355/529 lesions) than in the group without anticoagulation (76%, 485/641; p < 0.01). Vessel size was also significantly smaller in the group with no anticoagulation (3.21 +/- 0.50 mm vs 2.89 +/- 0.70 mm; p < 0.001). Procedural success was achieved in 96% of cases. Major complications occurred in 49 pts, including death (1%), emergency bypass surgery (2.7%), and myocardial infarction (2.1%). Subacute stent thrombosis, observed in 2.6% of the patients treated with anticoagulation, decreased to 1% in the last 499 patients receiving only antiplatelet drugs after high pressure stent expansion controlled with intravascular ultrasound (p < 0.05). Angiographic follow-up was obtained at a mean interval of 6.6 +/- 3.0 months in 718 patients (75% of the eligible candidates). The global restenosis rate (greater than 50% diameter stenosis) was 22%, with no statistically significant difference in patients with and without anticoagulation after stenting. Clinical follow-up was available in 890 patients at a mean interval of 14 +/- 17 months. Late cardiac events occurred in 251 patients and included: 159 repeat coronary angioplasties for restenosis (20%), 114 coronary angioplasties for de novo lesions (10%), 33 elective by-pass surgery operations (3.7%) and 42 late deaths (4.7%). At the most recent follow-up there were 719 pts (81%) free of anginal symptoms, including patients having repeat angioplasty for restenosis or disease progression. Coronary stenting has a low incidence of procedural complications and high-pressure ultrasound guided implantation has drastically reduced the risk of subacute thrombosis. Repeat procedures due to restenosis remain the most important limitation of the technique and do not seem to be affected by evolving technique and operator experience.

Angioplasty, Balloon, Coronary↗
PubMed1996

High-level regulated expression of the human G6PD gene in transgenic mice.

The glucose-6-phosphate dehydrogenase-encoding gene (G6PD) belongs to a group with constitutive expression in all tissues. The regulation of these housekeeping genes is poorly understood, as compared to what is known about many genes whose expression is restricted to a particular tissue or stage of development, and which are often regulated by locus control regions (LCR) able to act over wide distances. In order to identify sequences in human G6PD which are necessary for its expression, we have generated transgenic mice carrying a 20-kb G6PD construct, including only 2.5 kb of upstream and 2.0 kb of downstream flanking sequence. All mice which carried the transgene (TG) expressed it, and the levels of expression detected in a range of tissues from three independent lines of mice were comparable to that of the endogenous murine G6PD. The variation in enzyme activity from tissue to tissue was remarkably similar for both the TG and the endogenous gene, and was shown to be due in both cases to variations in the steady-state mRNA levels.

Animals↗
PubMed1996

A randomized comparison of combined ticlopidine and aspirin therapy versus aspirin therapy alone after successful intravascular ultrasound-guided stent implantation.

BACKGROUND: Previous studies have shown that it is feasible to withhold anticoagulation after a successful intracoronary stent procedure with a low incidence of stent thrombosis. The importance of specific antiplatelet agents when stenting is performed without anticoagulation is unknown. METHODS AND RESULTS: After successful intravascular ultrasound-guided stenting, 226 patients were randomly assigned to receive either aspirin therapy alone (n = 103) or a combination of ticlopidine and short-term aspirin therapy (n = 123). Primary angiographic and clinical end points were stent thrombosis, death, myocardial infarction, the need for postprocedure coronary artery bypass surgery or repeated angioplasty, and significant medication side effects requiring termination of the medication within the first month of a successful procedure. At 1 month, the rate of stent thrombosis was 2.9% in the aspirin only group and 0.8% in the ticlopidine-aspirin group (P = .2). Cumulative major clinical events after successful stenting occurred in 3.9% of the patients in the aspirin group and in 0.8% in the ticlopidine-aspirin group (P = .1). There were no medication side effects in the aspirin group; in the combined ticlopidine-aspirin group, medication side effects occurred in 3 patients (P = .2). CONCLUSIONS: At 1 month, there was no difference in the incidence of stent thrombosis or other clinical end points between the two poststent antiplatelet regimens. However, the relatively small size of the study and the low incidence of thrombosis events may have contributed to the failure to detect differences in angiographic and clinical end points between the two groups.

Aged↗
PubMed1996

Implantation of the peripheral Wallstent for diffuse lesions in coronary arteries and vein grafts.

The Wallstent (Schneider, Bulach, Switzerland) is available in different lengths without much compromise in flexibility and radial support compared to some other stents. We treated 24 patients (26 vessels) with diffuse coronary lesions or vein graft lesions with intravascular ultrasound-guided peripheral Wallstent implantation. Average balloon pressure during stent optimization was 16.4 +/- 2.7 atm. The stents could be successfully implanted in 24 vessels. Minimal lumen diameter and percent diameter stenosis after stenting were 3.60 +/- 0.62 mm and -8 +/- 13%, respectively. Average stent length was 63.7 +/- 22.7 mm. There was one procedure-related complication. After stenting, all patients were treated only with antiplatelet agents. During 1-month follow-up, there was one subacute stent thrombosis due to incomplete coverage of a distal dissection. These preliminary results show the feasibility of this novel approach in selected lesions.

Adult↗
PubMed1996

Acute recoil of Palmaz-Schatz stent: a rare cause of suboptimal stent implantation--report of two cases with intravascular ultrasound findings.

It is generally believed that the Palmaz-Schatz stent maintains a strong radial force, preventing stent recoil. However, the capacity to prevent recoil is largely governed by the hardness or resistance of the lesion. We report two cases of "acute Palmaz-Schatz stent recoil," documented by intravascular ultrasound, and suggest a novel treatment of this unusual problem.

Angioplasty, Balloon, Coronary↗
PubMed1996

A new lease of life for an old enzyme.

We review here some recent data about glucose-6-phosphate dehydrogenase (G6PD), the first and key regulatory enzyme of the pentose phosphate pathway. New evidence has been presented to suggest that malaria is a selective agent for G6PD deficiency, which is the most common enzymopathy in man, and that G6PD deficiency, generally considered to be a mild and benign condition, is significantly disadvantageous in certain environmental conditions. At the molecular level, the enzyme structure has recently been elucidated and mechanisms regulating G6PD gene expression have been determined. A G6PD knock-out mutation introduced in mouse cells makes them exquisitely sensitive to oxidative stress, indicating that this ubiquitous metabolic enzyme has a major role in the defence against oxidative stress, even in eukaryotic nucleated cells, which have several alternative routes for providing the same protection. Because of the high prevalence of G6PD deficiency in many populations, it is expected that these findings will prompt further studies to ascertain the putative role of G6PD deficiency in conditions such as carcinogenesis and ageing.

Animals↗
PubMed1996

Results of coronary stenting for restenosis.

OBJECTIVES: This study attempted to analyze immediate and long-term angiographic and clinical results of coronary stent implantation for restenosis in a consecutive group of patients. BACKGROUND: The rate of stent utilization in patients with coronary artery disease has increased exponentially in recent years. There are many unanswered questions about the use of stenting in patients with restenosis, particularly with respect to late clinical and angiographic results. METHODS: A total of 159 stents were implanted in 128 consecutive patients with 139 lesions (mean 1.3 stents/patient). A technique of optimal stent expansion was used in all patients, and intravascular ultrasound guidance with no subsequent anticoagulation was performed in 41 patients. RESULTS: Stent implantation was successful in 126 patients (98%). Four patients (3.1%) had complications (in two after successful stenting): death in one, emergency bypass surgery operation in two and subacute stent thrombosis in one. Stents were implanted with a final balloon size (mean +/- SD) of 3.5 +/- 0.5 mm and a mean maximal pressure of 11 +/- 4 atm (range 8 to 20). Angiographic restenosis occurred in 27 patients (25%). Regression analysis on clinical and angiographic variables for prediction of restenosis showed no statistical significance for any variable. Late events occurred in 23 patients (19%). The actuarial survival rate was 98% at 1 year and at 3 years, and the event-free survival rate including freedom from repeat angioplasty for restenosis was 95% and 76%, respectively. CONCLUSIONS: The late angiographic outcome, restenosis rate and total clinical events are favorable for selected patients undergoing stent implantation for the indication of restenosis.

Aged↗
PubMed1996

Transsternal transpericardial operations in the treatment of bronchopleural fistulas after pneumonectomy.

Between 1972 and 1993, 19 patients (15 males and 4 females) with bronchopleural fistulae and pleural empyema after pneumonectomy were treated with transsternal transpericardial operations and closure of the fistula. The underlying malignant disease was a non-small cell carcinoma in 12, a malignant epithelial mesothelioma in two, and an atypical carcinoid tumor in one case. One patient each presented with tuberculosis, chest trauma, and lung destroyed by bronchiectasis. Fistulas affected the right bronchial stump in 17, and the left in 2, cases after pneumonectomy. The time between pneumonectomy and transsternal transpericardial operation ranged between 1 month and 4 years. All patients were submitted to drainage and irrigation of the empyema cavity (2-4 weeks). In 16 patients a long bronchial stump was sutured or stapled, in three cases resection of a short stump with the distal trachea was followed by anastomosis of the trachea and left main stem bronchus. Irrigation of the pneumonectomy cavity was continued in all patients for 2 weeks. Transsternal transpericardial operation was successful in 15 patients. Two patients died in the first 30 days, of renal or respiratory failure without fistula recurrence. In two cases the fistula recurred; definitive healing was achieved using a great omentum flap and endoscopic application of fibrin glue and bone spongiosa. Transsternal transpericardial management of bronchus stump fistula after pneumonectomy is highly effective and offers advantages over the direct approach through the infected empyema cavity.

Adult↗
PubMed1996

MRI study of a physiotherapeutic protocol in anterior disk displacement without reduction.

Disk displacement of the temporomandibular joint (TMJ) without reduction has been considered a fundamental pathophysiologic abnormality of the joint. In this paper there are supportive clinical and MRI evidence of a successful repetitive manipulative technique for the treatment of acute and chronic locking. In 1500 treated cases, documented on videotape, only five cases required surgical intervention. The success of the therapy was confirmed by 13 MRI images of the TMJ of patients with acute and chronic locking before and after therapy. In all cases the anteriorly dislocated disk in closing and opening position was recaptured and repositioned in a normal position in the temporomandibular fossa. Three complete cases are reported with complete clinical and MRI documentation.

Adult↗
PubMed1996

Somatic-cell selection is a major determinant of the blood-cell phenotype in heterozygotes for glucose-6-phosphate dehydrogenase mutations causing severe enzyme deficiency.

X-chromosome inactivation in mammals is regarded as an essentially random process, but the resulting somatic-cell mosaicism creates the opportunity for cell selection. In most people with red-blood-cell glucose-6-phosphate dehydrogenase (G6PD) deficiency, the enzyme-deficient phenotype is only moderately expressed in nucleated cells. However, in a small subset of hemizygous males who suffer from chronic nonspherocytic hemolytic anemia, the underlying mutations (designated class I) cause more-severe G6PD deficiency, and this might provide an opportunity for selection in heterozygous females during development. In order to test this possibility we have analyzed four heterozygotes for class I G6PD mutations: two with G6PD Portici (1178G-->A) and two with G6PD Bari (1187C-->T). We found that in fractionated blood cell types (including erythroid, myeloid, and lymphoid cell lineages) there was a significant excess of G6PD-normal cells. The significant concordance that we have observed in the degree of imbalance in the different blood-cell lineages indicates that a selective mechanism is likely to operate at the level of pluripotent blood stem cells. Thus, it appears that severe G6PD deficiency affects adversely the proliferation or the survival of nucleated blood cells and that this phenotypic characteristic is critical during hematopoiesis.

Autoradiography↗
PubMed1995

Intracoronary stenting without anticoagulation accomplished with intravascular ultrasound guidance.

BACKGROUND: The placement of stents in coronary arteries has been shown to reduce restenosis in comparison to balloon angioplasty. However, clinical use of intracoronary stents is impeded by the risk of subacute stent thrombosis and complications associated with the anticoagulant regimen. To reduce these complications, the hypothesis that systemic anticoagulation is not necessary when adequate stent expansion is achieved was prospectively evaluated on a consecutive series of patients who received intracoronary stents. METHODS AND RESULTS: From March 1993 to January 1994, 359 patients underwent Palmaz-Schatz coronary stent insertion. After an initial successful angiographic result with < 20% stenosis by visual estimation had been achieved, intravascular ultrasound imaging was performed. Further balloon dilatation of the stent was guided by observation of the intravascular ultrasound images. All patients with adequate stent expansion confirmed by ultrasound were treated only with antiplatelet therapy (either ticlopidine for 1 month with short-term aspirin for 5 days or only aspirin) after the procedure. Clinical success (procedure success without early postprocedural events) at 2 months was achieved in 338 patients (94%). With an inflation pressure of 14.9 +/- 3.0 atm and a balloon-to-vessel ratio of 1.17 +/- 0.19, optimal stent expansion was achieved in 321 of the 334 patients (96%) who underwent intravascular ultrasound evaluation, with these patients receiving only antiplatelet therapy after the procedure. Despite the absence of anticoagulation, there were only two acute stent thromboses (0.6%) and one subacute stent thrombosis (0.3%) at 2-month clinical follow-up. Follow-up angiography at 3 to 6 months documented two additional occlusions (0.6%) at the stent site. At 6-month clinical follow-up, angiographically documented stent occlusion had occurred in 5 patients (1.6%). At 6-month clinical follow-up, there was a 5.7% incidence of myocardial infarction, a 6.4% rate of coronary bypass surgery, and a 1.9% incidence of death. Emergency intervention (emergency angioplasty or bailout stent) for a stent thrombosis event was performed in 3 patients (0.8%). The overall event rate was relatively high because of intraprocedural complications that occurred in 16 patients (4.5%). Intraprocedural complications, however, decreased to 1% when angiographically appropriately sized balloons were used for final stent dilations. There was one ischemic vascular complication that occurred at the time of the procedure and one ischemic vascular complication that occurred at the time of angiographic follow-up. By 6 months, repeat angioplasty for symptomatic restenosis was performed in 47 patients (13.1%). CONCLUSIONS: The Palmaz-Schatz stent can be safely inserted in coronary arteries without subsequent anticoagulation provided that stent expansion is adequate and there are no other flow-limiting lesions present. The use of high-pressure final balloon dilatations and confirmation of adequate stent expansion by intravascular ultrasound provide assurance that anticoagulation therapy can be safely omitted. This technique significantly reduces hospital time and vascular complications and has a low stent thrombosis rate.

Adult↗
PubMed1995

Age-related changes of whole skeleton and body composition in healthy men.

We examined age-related changes of the entire skeleton and its major anatomical areas (spine, trunk, pelvis, arms, legs) in 139 healthy males (19-99 years of age) and evaluated the influence of lean mass and fat mass on these changes. The population studied was stratified according to their ages referred in decades. Bone mineral density (BMD) and body composition (fat mass, lean mass) were measured by Lunar DPX. A negative linear correlation between BMD values and age was observed. The overall bone loss from the young to the aged was statistically significant for all skeletal sites, with a lower level of significance for the spinal area: BMD percentage decrease ranged from 19.4% for the pelvis to 9% for the spine. Peak bone mass was observed in the first decade (19-29 years of age). Soft tissue increased until the fifth and sixth decades, followed by a gradual decrease. Lean mass declined in a uniform way from the first to the last decades. BMD values were significantly related to lean mass, but there were no correlations with the fat mass. Lean body mass was significantly related to BMD/height, index of "true" volumetric density. Multiple regression analysis confirmed that in males the principal determinant of total body bone density is fat-free mass.

Absorptiometry, Photon↗
PubMed1995

Spectral characteristics of heart rate and blood pressure variability in primary aldosteronism.

A disturbance of the autonomic cardiovascular function has been postulated in primary aldosteronism as a possible mechanism for hypertension. Using the method of spectral analysis of heart rate and blood pressure variability, the aim of this study was to assess sympathovagal interactions modulating cardiovascular function and baroreflex control in patients with primary aldosteronism. Seventeen patients (7 with adenomas and 10 with idiopathic hyperaldosteronism) and a control group of 11 essential hypertensives (EH) and 10 normotensive subjects were studied. Continuous finger blood pressure was measured using a Finapres device and heart rate was measured using an electrocardiographic monitor. The studies were conducted in each patient for 20 min in the supine position and 10 min during a passive head-up tilt to 60 degrees. The low frequency and the low frequency-to-high frequency ratio of systolic and diastolic blood pressures were significantly higher both in primary aldosteronism and in EH patients compared with normotensives (P < .01). Impaired response to tilt was found in the heart rate and blood pressure variability in primary aldosteronism and EH patients; the increase in low frequency was smaller than in normotensives. Baroreflex gain (assessed by alpha index) was less in primary aldosteronism and EH patients as compared with normotensives. These findings may suggest that volume expansion or sympathetically mediated central translocation of the blood volume, or both, could stimulate the cardiopulmonary receptors and impair the baroreflex gain. Our findings suggest that an enhanced peripheral vascular responsiveness to a normal sympathetic outflow may be involved in the pathogenesis of hypertension in primary aldosteronism.

Baroreflex↗
PubMed1995

Ultrasonographic assessment of bone in normal Italian males and females.

Recently ultrasound techniques have been proposed to evaluate skeletal status. Speed of sound and attenuation through the bone are the ultrasound properties currently used to assess bone strength and fragility. The speed of sound in m s-1 (SOS), broadband ultrasound attenuation in dB MHz-1 (BUA) and stiffness (S) in 134 healthy females (age range 10-90 years) and in 100 healthy males (age range 10-93 years) was measured using the Achilles scanner (Lunar Corp., Madison, WI, USA). A polynomial function was applied to the observed data to evaluate a pattern of age-related BUA, SOS and S changes. Peak values of SOS, BUA and S were reached in both sexes at the age of 30 years. Average decreases of 12.9% in BUA, 4.9% in SOS and 28.9% in S were found in men aged between 30 and 90 years. In women average decreases of 17.2% in BUA, 4.2% in SOS and 31.9% in S were discovered in those aged between 30 and 90 years. The analysis of SOS, BUA and S changes between pre- and post-menopausal women revealed a significant decrease of these parameters with years since menopause. These data indicate an age-related decrease of ultrasound signals in both sexes. Furthermore, this technique is able to detect, in females, menopause related changes due to oestrogen failure. In contrast, in males, the age-related loss of ultrasound signals appears to be more linear.

Adolescent↗
PubMed1995

Clinical and angiographic outcome after Palmaz-Schatz stent implantation guided by intravascular ultrasound.

Intracoronary stents can be implanted with a low incidence of stent thrombosis (< 1%) when the stent procedure is guided by intravascular ultrasound. The long-term clinical and angiographic effects, however, have not been reported. This study assesses the 6 month clinical and angiographic results of a consecutive series of patients with intravascular ultrasound guided Palmaz-Schatz stent deployment that were not treated with subsequent anticoagulation after a successful stent implantation procedure. From March, 1993 to April 1994, 411 patients underwent Palmaz-Schatz stent implantation. There were 26 patients that had uncomplicated Palmaz-Schatz stent implantation that were treated with a standard anticoagulation regimen that are not evaluated in this study. Thus, this study includes an assessment of 385 patients that had either a successful intravascular ultrasound guided stent implantation procedure and did not receive post procedure anticoagulation or had a procedural complication. Procedural success was achieved in 369 patients (96%). Clinical success (procedure success without early post procedure event) was achieved in 363 patients (94%). There were 2 acute stent thrombosis events (0.5%) and 1 subacute stent thrombosis (0.3%) in the group of 369 patients with 454 lesions treated without anticoagulation. At 6 month clinical follow-up the incidence of myocardial infarction was 4.9% and the rate of coronary bypass surgery was 6.2%. There was a 2.1% incidence of death. Emergency intervention (emergency angioplasty or bailout stent implantation was necessary in 3 patients (0.8%). The total incidence of repeat percutaneous intervention was 11.4%. By 6 months clinical follow-up, major events had occurred in 19.2% of patients. The angiographic lesion restenosis rate, according to 50% diameter stenosis criteria, was 19%. The incidence of restenosis per patient was 22%. In conclusion, intravascular ultrasound guided Palmaz-Schatz can be performed without subsequent anticoagulation with a low incidence of stent thrombosis and acceptable clinical and angiographic outcome at 6 month clinical follow-up.

Anticoagulants↗
PubMed1995

Idiopathic avascular necrosis of the scaphoid. A case report.

Avascular necrosis of the carpal scaphoid is a common disorder after a trauma, i.e. a fracture or mild and repetitive injury. Sometime it can be associated with a systemic disease or chronic steroid intake. Rarely avascular necrosis is found in the absence of a known etiology and so termed "idiopathic". We report a case of idiopathic avascular necrosis of the scaphoid. A painful wrist of six months' duration was observed in a 62-year-old housewife. No history of trauma or steroid administration could be elicited. X-ray showed an osteolytic area with irregular edges surrounded by a ring of osteosclerosis at the proximal pole of the left scaphoid. This datum was confirmed by the magnetic resonance imaging.

Carpal Bones↗
PubMed1994

A novel single-base mutation in the glucose 6-phosphate dehydrogenase gene is associated with chronic non-spherocytic haemolytic anaemia.

More than 80 variants of glucose-6-phosphate dehydrogenase (G6PD) are associated with chronic nonspherocytic haemolytic anaemia (CNSHA); however, the molecular basis of this association is not fully understood. We have used the polymerase chain reaction and nucleotide sequence analysis to characterize a new G6PD variant, which we designate as G6PD Bari, in a G6PD-deficient boy affected by CNSHA. A single mutation leading to an amino-acid substitution was detected in the G6PD coding region, viz. a C->T transition at position 1187 predicting leucine at residue 396 in the enzyme; proline is invariably present in evolutionary distant G6PD molecules at this position. Inheritance in the patient's family was demonstrated by the polymerase chain reaction followed by diagnostic restriction enzyme analysis. The C->T transition responsible for G6PD Bari maps close to several other mutations previously identified in G6PD variants associated with CNSHA.

Adolescent↗