Biomedical subjects

F Di Gregorio

Publications and source records attributed to F Di Gregorio.

117 records · Page 7Linked to original sources

PubMedDate not supplied

Atrial natriuretic factor and sympathetic activation in human heart failure.

The neurohormonal changes occur early, have important prognostic value, and may play a role in the evolution and progression of heart failure in man. Atrial natriuretic factor (ANF) is a natriuretic and vasorelaxant peptide. Previous studies indicated that plasma ANF provides prognostic information and, ANF levels closely related to both severity of disease and catecholamine levels but, it is still unclear if high circulating levels of ANF, which are present in heart failure constantly, may be to correlate with sympathetic nervous activity in man. Thus, the aim of the present study was to investigate the relations between the release of ANF and the sympathetic system in human heart failure. We studied 18 patients with heart failure (CHF) and a control Group (n = 14) of healthy subjects. To induce adrenergic activation in physiologic way patients were underwent to a low-exercise by cycle-ergometer in supine position. Blood was collected at rest, and immediately after exercise for determination of plasma levels of ANF, norepinephrine and epinephrine levels. ANF values at rest were 35.9 +/- 19.2 pg/ml in controls and 190.7 +/- 34.2 pg/ml (p < 0.001 vs controls) in CHF patients. As well norepinephrine levels showed higher values in patients (295.7 +/- 47.8 pg/ml), than in normal subjects (143.5 +/- 33.3 pg/ml; p < 0.01). In CHF patients epinephrine levels were 100.1 +/- 21.2 pg/ml (p < 0.01 vs controls). ANF levels were in normal subjects 87.9 +/- 19.2 pg/ml (p < 0.01 vs rest) after exercise. In CHF patients ANF values were 275.3 +/- 59.8 pg/ml; p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial Natriuretic Factor↗

PubMedDate not supplied

[The relations between atrial natriuretic factor release and adrenergic activation in hypertrophic cardiomyopathy].

Atrial natriuretic factor (ANF) is a potent natriuretic and vasoactive (vasorelaxant) peptide localized in the secretory-like atrial specific granules. The main peptide in this storage granules is the 126 amino acid proatrial natriuretic peptide, but the principal circulating form in human plasma is the 28 amino acid, alpha-human natriuretic peptide. Animal and in vitro studies have suggested that ANF modulates autonomic circulatory control, probably with a dose-dependent mechanism. Moreover, recent human studies have resulted contradictory. In particular, it is still unclear if high circulating levels of ANF, which are present in congestive heart diseases constantly, may be correlated with sympathetic nervous system activity in man. Previously we have shown that in congestive diseases there is a relation between ANF and catecholamine secretion. From these basis, the aim of this study was to investigate on the pathophysiological relations between atrial natriuretic factor (ANF) release and adrenergic activation in patients with obstructive hypertrophic cardiomyopathy (n = 6) and non obstructive hypertrophic cardiomyopathy (n = 4). Sympathetic activation in physiologic way was induced by cycloergometer sub-maximal exercise. Then specimens of venous blood were achieved for plasma determination of ANF and catecholamines pre- and post-exercise. Results have shown that in obstructive hypertrophic cardiomyopathy patients basal levels of ANF and catecholamines were higher than levels of these parameters in non obstructive hypertrophic cardiomyopathy patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMedDate not supplied

Venous interruption as prophylaxis of pulmonary embolism: vena cava filters.

Interruption of vena cava for prevention of pulmonary embolism (PE) was achieved in the past with surgical ligation or placement of clips outside the infrarenal vena cava. At present, this procedure is performed with percutaneous insertion of vena cava filters. Vena cava filters can be permanent or temporary, catheter-retrievable. Main indications for placement of a vena cava filter are: contraindication for anticoagulant therapy in patients with severe PE in whom a further embolic episode would be fatal or patients with PE (or its recurrence) undergoing adequate anticoagulant therapy. Temporary filters are reserved to patients where the risk of PE is limited in time as in posttraumatic, post-partum or postoperative thromboembolism. The incidence of recurrence after placement of a vena cava filter varies between 0.5 and 7%. Procedure-associated complications are usually mild. However, severe complications as filter migration into the pulmonary artery or vena cava perforation were described. Our experience concerns the insertion of 61 vena cava filters (47 permanent and 14 temporary). Indications were as follows: iliofemoral thrombosis at embolic risk (37 cases), contraindication for anticoagulant therapy in the presence of deep vein thrombosis with embolic risk (7 cases), protection during fibrinolytic therapy (3 cases), PE during anticoagulant therapy (5 cases) complications of anticoagulant therapy which required discontinuation (5 cases), prophylaxis in view of surgery at high risk for PE (2 cases), protection for surgical venous thrombectomy (2 cases). Mortality was nil. Clinically evident PE was not observed in any patient in whom vena cava filter was inserted. Complications were mild and asymptomatic. Vena cava filters represent an effective prevention of PE together with medical and surgical treatment. At present, problems of this procedure are not technical but rather concern correct indications. Interruption of vena cava is effective if planned within a global strategy for prevention of thromboembolism.

Adolescent↗

PubMedDate not supplied

Role of angiography in the evaluation of hepatic perfusion.

Angiography was the first method to be used for a morphofunctional study of hepatic perfusion. It can be performed with direct puncture of portal system or indirect opacification after contrast injection into the splenic artery or superior mesenteric artery. At present, direct angiographic procedures have only a historical value in the diagnostic approach while they have a preliminary role in interventional maneuvers on the portal system (TIPSS, embolization of portal branches or left gastric vein). Indirect angiographic procedures allow the study of arteries, parenchymas and portal system. Much of the information on arterial hepatic and portal circulation is now supplied by noninvasive procedures (US,CT,MRI); however in selected cases, angiography can be performed. Furthermore, the knowledge of angiographic findings of hepatic circulation is basic to the interpretation of "functional" information supplied by color-Doppler US, spiral CT and MR angiography.

Angiography↗

PubMedDate not supplied

[Integrated role of computerized tomography and magnetic resonance imaging in identifying the early changes in rheumatoid arthritis of the craniocervical junction].

Any cervical spine segment may be affected by rheumatoid arthritis, but destructive changes are most prominent at the craniocervical junction. Cervical involvement is a devastating complication of the disease, because of the risk of a range of neurological complications (paresthesia, cervical myelopathy, vertebro-basilar insufficiency), and even sudden death from medullary compression. However, the incidence of both cervical rheumatoid arthritis and its neurological complications are still debated, being respectively reported in 17-86% and 11-70% of the patients, according to the variability in neurological and radiologic classification systems adopted by the authors. To assess the incidence of cervical rheumatoid arthritis and the integrated role of different imaging techniques in its diagnosis, 38 consecutive patients (29 women and 9 men) with rheumatoid arthritis according to the American Rheumatism Association criteria were examined. The average age was 60 years (range: 27-70 years) with a mean disease duration of 6.6 years (range: 6 months-25 years). All the patients underwent conventional radiography of the cervical spine, unenhanced Computed Tomography (CT) of the craniocervical junction and unenhanced and Gadolinium-enhanced Magnetic Resonance Imaging (MRI) of the cervical spine. Cervical spine involvement was demonstrated in 25/38 (66%) patients 20 women and 5 men, with an average age of 57 years and a mean disease duration of 8.5 years. In 13 of them (mean disease duration: 12.7 years), the diagnosis was made with radiography which showed atlantoaxial and subaxial subluxations and/or erosions. Of the 12 patients with negative conventional radiography (mean disease duration: 2.5 years), 4 were identified with both CT and MRI (synovial pannus and erosions). 3 with MRI only (joint effusion/hypervascularized synovial pannus), and 5 exhibited questionable CT findings which were clarified only by MR demonstration of inflammatory tissue contiguous to suspicious irregularities of the cortical bone of the odontoid process. 52% (13/25) of cervical rheumatoid arthritis patients were identified with plain radiographs, 68% (17/25) with CT and 100% (25/25) with MRI. Our preliminary data show that a specific tool for the diagnosis is recommended even in the early disease phases since rheumatoid arthritis commonly affects the craniocervical junction. Studying the craniocervical region is clinically difficult, and diagnostic imaging assessment is essential. Conventional radiography allowed to detect more than half the patients with cervical rheumatoid arthritis, but only in advanced disease stages. On the contrary, MRI had the unique potential of direct and detailed synovial visualization, thus permitting the diagnosis of cervical involvement even in the early phases of the inflammatory process, when CT findings were still negative or questionable.

Adult↗

PubMedDate not supplied

Diagnostic imaging of the diabetic foot.

Diagnostic imaging plays a major role in the osteoarticular disease of the foot in diabetics, allowing the diagnosis and evaluation of alterations for therapy planning. To-date conventional radiology is still of first choice in the study of the diabetic foot with the evaluation of osteoarticular damage caused by neuropathy and vascular disease. Major radiographic patterns are neuroarthropathy and osteomyelitis. Main locations are at the level of forefoot and less frequently of tarsus and tibiotarsal joint. Second choice procedures as US, CT and MRI are useful for a more accurate evaluation of soft tissue lesions and articular structures. US is the first choice procedure in soft tissue evaluation to rule out the presence of abscesses which require surgery. MRI with some limitations represents the gold standard for the study of joints and medullary disease. Spiral CT though less specific and sensitive than MRI for soft tissue and bone marrow study is still the exam of reference for the study of bone structures with three-dimensional reconstructions useful to plan orthopedic surgery.

Diabetic Foot↗

PubMedDate not supplied

The diabetic foot: role of color-Doppler US.

Color Doppler US is a first choice instrumental exam for the diagnosis and staging of peripheral arterial occlusive disease in diabetic patients. Normal and pathological findings are analyzed to establish the potential and limitations of the procedure. Color Doppler US is a noninvasive, reproducible and cost-effective procedure. Direct morphologic and flowmetric evaluations of stenotic-occlusive alterations, and indirect evaluations based on the interpretation of velocimetry findings proximal and distal to the lesions, are feasible. The conventional basic exam can be enhanced with the power module. Encouraging experimental results are observed with the use of echographic contrast media. Disadvantages of the procedure are related to the poor panoramic view, subjective (operator-dependent) interpretation and limitations related to the physics of ultrasound.

Diabetic Foot↗

PubMedDate not supplied

[Microcytosis. A hematological characteristic common to diverse diseases].

The pathological conditions characterized by microcytosis are reviewed and their pathophysiological mechanisms also at the molecular level are described. Moreover clinical, haematological and laboratory findings for differential diagnosis are discussed. Finally, the most efficacious schedules for the treatment of iron deficiency anaemia are reported.

Adolescent↗

PubMedDate not supplied

[Calcium phosphate metabolism in thalassemia].

The AA. performed a screening test on 113 patients affected by beta thalassemia major ranging between 2 and 40 years of age, randomized among those who come to the Microcitemic Center of our Institute, and on a control group. In all of them serum levels of calcium, phosphate, parathyroid hormone (PTH), calcitonin and 25-OH vitamin D were measured. Average serum levels of PTH were significantly (P < 0.001) lower in our patients than in control group and 12.4% of the former were clearly under normal range, especially in the group over 16 years of age. Also serum levels of 25-OH vitamin D were lower in thalassemic patients than in controls, because of the presence of 32 patients with average values under normal limit. Our results are in agreement with current literature and underline the increasing incidence of endocrine complications in thalassemic patients who undergo high transfusion regimens, because of to the increase of hemosiderosis due to the low compliance to iron chelation therapy. Controversial is the pathogenesis of the absence of hypocalcemia in many patients with hypoparathyroidism and the cause of the deficit of vitamin D.

Adolescent↗