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Biomedical subjects

V De Santis

Publications and source records attributed to V De Santis.

At least 19 recordsLinked to original sources
PubMed2006

Preconditioning effects of levosimendan in coronary artery bypass grafting--a pilot study.

BACKGROUND: The calcium sensitizer levosimendan protects against myocardial ischaemia and reperfusion injury in animal models. METHODS: The present pilot study investigated whether a short infusion before coronary artery bypass grafting (CABG) would protect the myocardium and improve postoperative haemodynamics. Twenty-four patients with stable angina undergoing elective CABG surgery were randomized to receive either placebo or levosimendan (24 microg kg(-1)) infused i.v. over a 10 min period just before placing the patient on cardiopulmonary bypass. RESULTS: Perioperative haemodynamic variables, concentrations of cardiac troponin I over the 48 h postoperative period, and clinical outcomes were assessed. There were no adverse effects related to levosimendan. Compared with control patients, levosimendan-treated patients had lower postoperative troponin I concentrations (P<0.05) and a higher cardiac index (P<0.05). CONCLUSION: Patients receiving a short infusion of levosimendan before CABG showed evidence of less myocardial damage, suggestive of a preconditioning effect. Larger outcome studies are thus indicated to confirm benefit.

Aged↗
PubMed2003

Osseointegration in hip prostheses: experimental study in sheep.

Sixteen 2- to 3-year-old sheep were submitted to a hemiarthroplasty of the hip joint with a specially designed femoral component. The proximal two thirds of the stem had a circumferential, plasma-sprayed, porous coating with hydroxyapatite. The animals where killed a 15, 30, 60, 90, 120, 180, 200, 270, 360, and 540 days after surgery. Femurs were submitted to plain radiographs, computerised tomography (CT) scan, and dual energy X-ray absorptiometry (DEXA). Cross-sections were obtained at four different levels and studied using scanning electron microscopy. In the coated portion of the stem, apposition of woven immature bone was evident at 15-30 days and mature lamellar bone by 30 days. With time, the gap between the endosteum and the coated surface was filled by bridges of lamellar bone with a marked trabecular orientation. In the distal uncoated portion of the stem, the implant was initially surrounded by fibrous tissue that, with time, transformed into lamellar bone.

Animals↗
PubMed2003

Reliability of the Ahlbäck classification of knee osteoarthritis.

OBJECTIVE: The aim of the study was to assess the inter-observer reliability and intra-observer reproducibility of the Ahlbäck radiographic classification for knee osteoarthritis (OA). DESIGN: Ninety-six knee radiographs of patients with clinical signs of arthritis were evaluated and classified into five grades of Ahlbäck classification by three observers with different experience. The evaluation was repeated after 1 month. The inter- and intra-rater agreements were assessed by statistical analysis (k and k(w)coefficients). RESULTS: The inter-observer agreement was statistically significant, but with low or medium values of the coefficients. The intra-rater agreement was less significant than the inter-rater. Inter- and intra-rater agreement coefficients decreased when the cases of stage V arthritis were excluded from the analysis. The evaluations were influenced by the age and working experiences of each observer. CONCLUSIONS: The authors stress that the Ahlbäck classification, as routinely applied, should not be used in orthopaedic surgery without the support of clinical and/or arthroscopic examinations, because of its poor reliability.

Aged↗
PubMed2003

Acrylic cement added with antiblastics in the treatment of bone metastases. Ultrastructural and in vitro analysis.

An increased long-term survival of patients with alignant tumours also increases the possibility of the development of skeletal metastases and pathological fractures. The management of bone metastases includes the removal of gross disease and the administration of local adjuvants. We have investigated the possibility of adding antiblastic drugs to acrylic cement. Cylinders of acrylic cement were manufactured containing three different antiblastic drugs, methotrexate, cisplatin and doxorubicin. We performed in vitro analysis on MCF-7 human breast cancer cells in order to evaluate the biological effect of the mixtures and surface analysis of the acrylic cement-cisplatin cylinders using energy-dispersive x-ray analysis (EDAX). All drugs were released in an active form from the cement. Each drug had a different effect on cell viability. Doxorubicin had the greatest effect on breast cancer cells. Surface analysis showed that antiblastic drugs were present in the form of granules. These results confirm the potential of antiblastic-loaded cement as a possible adjuvant in the local treatment of bone metastases. Further studies should be undertaken to determine whether the release of antiblastic drugs from cement is elution or if they are only released from the surface.

Antineoplastic Agents↗
PubMed2002

Biomechanical factors affecting progression of structural scoliotic curves of the spine.

The development of the spine is affected by both biological and mechanical factors. As the geometry of the motion segment changes throughout growth, so does the mechanical behaviour of the spine owing to changing vectors acting on a variable geometry system. The biomechanical analysis of the growing spine enables the assessment of the role played by biological and mechanical factors in the pathogenesis of progressive scoliosis to be assessed and its comparison with factors acting on an adult scoliotic spine. The knowledge of these principles is instrumental to setting the right parameters for treatment and to design braces that may be capable of obtaining correction of the deformity. The elastic behaviour of child and adult spine differs because of both physiologic and pathologic conditions. In child scoliosis an abnormal geometry causes a persistent stress concentration in crucial areas of the motion segment. This induces a progressive elasto-plastic strain which modifies the geometry of the motion segment, thus worsening the stress concentration and the excessive strain through a vicious cycle. In adult scoliosis, on the other hand, deformation primarily affects the viscous-elastic structures, namely the intervertebral disc and the capsulo-ligamentous structures. This produces instabilty of the motion segments and slow deformation of the vertebrae through remodelling. It therefore ensues that the aim of the treatment differs in both conditions. In the child spine the aim is to prevent the motion segment deformity by means of braces which adequately modifies the stress distribution acting on the spine, thus enabling the spine to grow according to a quasi-physiological model. In adult scoliosis a stable equilibrium is required in order to prevent further deformation of the motion segment.

Adolescent↗
PubMed2002

Study of vertebral morphology in Scheuermann's kyphosis before and after treatment.

Variation of vertebral morphology in Scheuermann's Kyphosis before and after orthopedic treatment is usually measured by the entity of the curve, using Cobb's method, and by vertebral wedging. But the lack of correlation between these parameters and the clinical evolution of the deformity, lead to the possibility of other alterations that can explain part of the kyphosis deformities before and after the treatment. In this group of alterations the inclination of anterior and posterior walls, that express the trapezoid deformity of vertebras, seem to be more reliable indicators of curve response to ortopedic treatment.

Adolescent↗
PubMed2000

Surface analysis of a femoral stem after failed total hip replacement.

We analysed the surface of a Ti alloy femoral stem in a cementless total hip replacement with early failure. A specific protocol consisting of non destructive and destructive tests was used in the evaluation of the retrieved stem. The tests confirmed that implant fretting due to bone abrasion constitutes an early phase of loosening.

Aged↗
PubMed1990

Hypothyroidism in patients with thalassemia syndromes.

Sixty transfusion-dependent thalassemic patients were studied by simultaneous measurement of circulating thyroid hormones, basal thyroid-stimulating hormone (TSH) and TSH response to thyrotropin-releasing hormone with the aim of evaluating the frequency of hypothyroidism in such patients, and the relationship between hypothyroidism and compliance with treatment and iron overload. Thyroid failure was present in 31 of the 60 patients. A correlation was found between impairment of thyroid functions, duration of chronic hypoxia and the activities of various transaminases. The results of this study emphasize the importance of early evaluation of thyroid function in thalassemic patients and suggest that anemia and hypoxia may potentiate the toxicity of iron deposition in endocrine glands.

Adolescent↗
PubMed1989

Vulvo-vaginal condylomatosis and relapse: combined treatment with electrocauterization and beta-interferon.

The therapeutical effectiveness of beta-interferon and the possibility of reducing the incidence of relapses were evaluated by selecting three groups of patients affected with three forms of condylomatosis and submitting then to various treatments. In the first group of sixty patients treated with beta-interferon, we obtained the best results in micro-condylomatosis (a 100% response), while florid condylomatosis responded less well to the treatment (72% with no response). In the second group of ten patients, electrocoagulation of florid condylomata determined a complete response (CR) in seven cases (70%). Moreover, immunoperoxidase identified three case of sub-clinical infection, two of which relapsed. In the third group of ten patients, we combined electrocoagulation with beta-interferon. This combination showed the effectiveness of beta-interferon in decreasing relapses. This result is evident if we consider that only one out of four patients with immunoperoxidase-positive biopsy relapsed.

Adolescent↗
PubMed1986

Health risks of SO2 released from coal-fired plants: a model for general evaluations.

A model recently proposed for evaluation of health risks from airborne effluents released by the nuclear cycle is applied to SO2 release by coal-fired plants. The main feature of the model is that it makes such evaluations extremely simple by not requiring any detailed knowledge of the local concentrations of the pollutant considered. A schematization of the behavior of the pollutant into the atmosphere is proposed taking into account deposition and SO2-SO4 conversion. An example of application is worked out and discussed.

Air Pollutants↗
PubMed1985

Health effects of airborne effluents released from the nuclear cycle.

Current trends in regulations governing radioactive release from the nuclear cycle and their relationship with population dose and population health damage evaluation are discussed. It is shown that, at least in some cases, current methods may not grant a correct population-dose evaluation. A procedure to better evaluate population doses from gaseous effluents is outlined. It leads to a very simple first approximation expression which is independent of the dispersion area. Two examples, 85Kr and 222Rn, are worked out in order to give first-order evaluations of the population-dose commitment and the related risk. Strong discrepancies between the results and current evaluations are found and discussed.

Air Pollutants↗
PubMed1984

Coal energy vs nuclear energy: a comparison of the radiological risks.

We examined past and current work comparing radiological risks from coal-fired and nuclear plants. We found some errors and under- and over-evaluations. They appear to be generally in the direction of maximizing coal risks and minimizing nuclear risks. Our analysis removes these apparent inconsistencies and takes full account of the Suess effect and shows that the radiological risks from coal-fired plants are fully counterbalanced by this effect and are, in any case, small in comparison with those from nuclear plants.

Coal↗
PubMedDate not supplied

Surgical management of instability of the lumbar spine.

The surgical management of clinical spinal instability is for many aspects controversial since the lack of a precise clinical and instrumental definition of instability complicates the implementation of a therapeutic protocol. Both the indications and the surgical procedure are not always well defined. Some of the most common surgical techniques used in the most frequent causes of instability of the lumbar spine: fractures, degenerative disease and spondylolisthesis, are described.

Humans↗