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Biomedical subjects

M Fini

Publications and source records attributed to M Fini.

At least 91 records · Page 5Linked to original sources
PubMed2002

Atherosclerosis and cancer: common pathways on the vascular endothelium.

This article reviews experimental and clinical data on atherosclerosis and cancer showing common pathogenic mechanisms. It is suggested that common pathways follow dysfunction of the vascular endothelium. The activation of the haemostatic system and the overexpression of cytokines and adhesion molecules by the endothelial cells represent important features of this dysfunction. These mechanisms can be responsible for progression of both diseases and explain the higher incidence of thromboembolic events in cancer patients, the occurrence of similar laboratory findings and the effect of many drugs on the course of the two diseases. Our article confirms that atherosclerosis and cancer share common mechanisms, and we hope it will stimulate further clinical trials on the use of drugs active on the haemostatic system in cancer patients.

Animals↗
PubMed2002

L-arginine and L-lysine stimulation on cultured human osteoblasts.

Essential amino acids, such as L-Arginine (Arg) and L-Lysine (Lys), are involved in bone metabolism and growth. Our previous studies analyzed the effect of these amino acids on rat osteoblast cultures and in experimental animals. In this study, we evaluated the effect of L-Arg and L-Lys on cultured human osteoblasts. Primary human osteoblast cultures were divided into four groups: the Arg Group received 0.625 mg/ml per day of Arg, the Lys Group 0.587 mg/ml per day of Lys, the Arg-Lys Group received both amino acids, whereas the Control Group was sham-treated. After 7 days, the following parameters were tested in all groups: alkaline phosphatase (ALP), nitric oxide (NO), calcium (Ca), phosphorus (P), osteocalcin (OC), type I collagen (PICP), interleukin-6 (IL-6), transforming growth factor-beta 1 (TGF-beta 1) on culture supernatant, platelet derived growth factor (PDGF), insulin-like growth factor-I (IGF-I), and MTT proliferation test on cells. Arg administration significantly increased ALP, NO, PICP and IGF-I production and reduced the level of IL-6. Lys administration over the same time interval mainly affected cell proliferation, as evidenced by the MTT test and immunostaining for PDGF. The same positive effects evidenced by the single administrations of the two amino acids resulted from their simultaneous administration. However, synergism could be demonstrated only for the decrease in the level of IL-6. Arg and Lys show a positive effect on human osteoblasts, which is related partly to the production of those factors required for matrix synthesis, and partly to the direct or mediated activation of cell proliferation.

Arginine↗
PubMed2002

Osseointegration of sandblasted or anodised hydrothermally-treated titanium implants: mechanical, histomorphometric and bone hardness measurements.

The improvement of the implant-bone interface is still an open problem in the long-term mechanical stability of cementless fixed implants. Mechanical, histomorphometric and bone hardness measurements were performed in sheep femoral cortical bone implants at 8 and 12 weeks from surgery to compare in vivo the osseointegration of titanium screws (psi 3.5 mm x 7 mm length) with two different surface treatments: sandblasting with 70-100 microm HA followed by acid etching with HNO3 (Group A) and Ca-P anodization followed by a hydrothermal treatment (Group B). No significant differences were found for maximum push-out force and interfacial strength between groups at both experimental times. No significant difference was observed for Bone Ingrowth between groups at both experimental times, while the Affinity Index of Group B was significantly higher (7.5%, p<0.05) and lower (10.2%, p<0.05) than that of Group A at 8 and 12 weeks, respectively. Finally, a significant increase in bone microhardness measured within 200 microm from the interface and inside the thread depth of Group A was observed between the two experimental times (p<0.05). In conclusion, present findings show that osseointegration may be accelerated by adequate surface roughness and bioactive ceramic coating such as current tested treatments which enhance bone interlocking and mineralization.

Animals↗
PubMed2002

Fabricated hyalS micropatterns and surface guidance of NCTC 2544 continuous cell line: an in vitro study.

Surface topography is important in establishing tissue organisation adjacent to implants, smooth surfaces generally being associated with fibrous encapsulation. By virtue of its large hydrated molecular volume and its capacity to form molecular matrix, hyaluronic acid can expand the interfibrillar collagen spaces to allow the movement of cells, although it can also hamper their locomotion. Low molecular-weight hyaluronan can also stimulate cell proliferation, especially at low concentrations. The aim of the present work was to evaluate in vitro the growth and migratory behaviour of NCTC 2544 keratinocytes cultured on different materials microstructured with hyaluronic acid or sulfated hyaluronic acid to assess the possibility of using these devices in the repair process of soft tissues. Ultrastructural morphological analyses, morphometric evaluations and detection of cytoskeletal elements were performed. Our observations provide evidence that micrometer-size parallel grooves of hyaluronic acid can influence cell growth behaviour since cells seeded onto the microstructured substrate arranged themselves according to a shape and an orientation that clearly reflected the chemotropism exerted on them by the two forms of acid. These data also highlight the importance of accurate microtexture fabrication. We intend to follow up these in vitro studies with in vivo experimental applications using PET and gelatin substrates structured with HyalS to evaluate wound healing responses, and to extend our investigations of the cytoskeletal modifications induced by different microstructures.

Adjuvants, Immunologic↗
PubMed2002

Brucella spondylitis with paravertebral abscess due to Brucella melitensis infection: a case report.

This report describes the case of a 45-year-old woman with a 5-month history of fever, generalized malaise, myalgia, lower back pain and difficulty in walking. Serodiagnosis for brucella, carried out at the onset of symptoms 5 months previously, was negative. When the patient was admitted to our hospital there was contracture of the paraspinal muscles but no peripheral nerve damage. Laboratory tests showed positive agglutination for Brucella and an increase in the rate of dilution from 1/160 to 1/640 over 2 weeks. Radiographs and a computed tomography scan of the spine revealed bone erosion in the posterior borders of the L4-L5 vertebral end plates and a soft tissue mass surrounding the interposed disc and protruding into the spinal canal. Magnetic resonance imaging confirmed the presence of a paraspinal abscess around the affected disc and tissue edema. Culture tests of the blood and abscess tissue, taken by biopsy, were negative. Rifampicin treatment (600 mg daily), combined with a bust cast to immobilize the spine, led to clinical healing without the need for surgery. Because onset symptoms are nonspecific and insidious, in nonrisk subjects a diagnosis of brucellosis may sometimes be suspected only if there are local symptoms. The phenomenon of the absence of positivity in patients with a high antibody titer should also be considered Cases such as that described herein demonstrate the need for culture tests and serodiagnosis, even in nonrisk patients with persistent fever and arthralgia, to prevent the later complications of brucellosis.

Abscess↗
PubMed2001

Effect of estradiol valerate alone or in association with cyproterone acetate upon vascular function of postmenopausal women at increased risk for cardiovascular disease.

OBJECTIVES: a large body of evidence has been accumulated suggesting that impairment of vascular endothelial function is an initial step in the development of atherosclerosis. Recent studies have shown that estrogen replacement therapy in postmenopausal women (PMW) improves endothelium-dependent, flow-mediated dilatation (FMD) while the cyclical adjunct of a progestin may reverse this effect. METHODS: the purpose of this study was to evaluate endothelium-dependent, FMD in the brachial artery and the plasma levels of Endothelin-1 in menopausal females treated with estradiol valerate with and without cyclical cyproterone acetate in 20 PMW (mean age 64+/-6 years) with more than one risk factor for coronary artery disease. After a baseline evaluation, PMW entered a double-blinded, placebo controlled single cross-over study and were randomized to receive either estradiol valerate (2 mg) for 21 days or estradiol valerate (2 mg) for 11 days and estradiol valerate (2 mg) and cyproterone acetate (1 mg) for 10 days. Patients were crossed-over the complementary treatment 7 days after completing the first treatment phase. The study of forearm blood flow was repeated at the end of each treatment period. RESULTS: estradiol valerate significantly increased FMD as compared with baseline (12+/-3 vs. 7+/-4%, P<0.01) the adjunct of cyproterone acetate did not affect the effect of estradiol valerate upon FMD (12+/-3 vs. 11+/-4%, P=NS). Similarly reactive hyperemic flow increased after estradiol valerate alone (24%) or in association with cyproterone acetate (24%) compared with baseline. Plasma levels of Endothelin-1 were significantly reduced by estradiol valerate alone or in association with cyproterone acetate. CONCLUSIONS: in conclusion hormone replacement therapy with estradiol valerate and cyproterone acetate improves endothelial function and reduces plasma levels of Endothelin-1 in PMW at risk of coronary artery disease. These effects may be relevant for cardioprotection.

Brachial Artery↗
PubMed2001

Anti-ischemic effect of chronic oestrogen replacement therapy alone or in combination with medroxyprogesterone acetate in different replacement schemes.

BACKGROUND: Oestrogen replacement therapy in postmenopausal women has a protective effect upon the cardiovascular system and improves exercise-induced myocardial ischemia. Although in hormone replacement schemes progestins are required to reduce the likelihood of uterine malignancies, little is known on the cardiovascular effect of progestins. The purpose of this study was to evaluate the effect of oestrogen replacement alone and two different estrogen-progestin replacement therapy schemes upon exercise induced myocardial ischemia. MATERIAL AND METHOD: The study population included 18 female menopausal patients with coronary artery disease. After a baseline exercise test patients received conjugated equine estrogens (CEE) 0.625 mg alone for 30 days when they underwent a second exercise test and were randomized to receive in a cross-over design medroxyprogesterone acetate (MPA) either in continuous combined therapy (2.5 mg/daily) for 28 days or in cyclical therapy (10 mg o.d. from day 16 to day 28). RESULTS: After CEE alone two patients with a previously positive exercise test showed a negative exercise test. CEE increased time to 1 mm ST compared to baseline (352+/-185 vs 265+/-133 s, P<0.01). In the 2 pts in whom the exercise test was negative after CEE the test remained negative during continuous combined MPA therapy while become positive during cyclical MPA. CEE+continuous combined MPA increased both time to 1 mm ST and exercise time compared to baseline (386+/-165 vs 265+/-133 s, P<0.01 and 545+/-198 vs 465+/-186 s, P<0.05, respectively). No difference was found between baseline and CEE+cyclical MPA in either time to 1 mm ST or exercise time (268+/-164 vs 265+/-133 s, P=NS and 455+/-223 vs 465+/-186 s, P=NS, respectively). CONCLUSION: Continuous combined therapy with CEE+MPA improves exercise-induced myocardial ischemia in female patients with coronary artery disease while the beneficial effect of CEE is reduced by cyclical therapy.

Aged↗
PubMed2001

Basic fibroblast growth factor enhances in vitro mineralization of rat bone marrow stromal cells grown on non-woven hyaluronic acid based polymer scaffold.

A biodegradable non-woven hyaluronic acid polymer scaffold (Hyaff 11) was analysed in vitro as a carrier vehicle for differentiation and mineralization of rat bone marrow stromal cells (BMSC). BMSC were grown on Hyaff 11 in a mineralizing medium in the presence/absence of basic fibroblast growth factor (bFGF). Osteoblastic differentiation was investigated by light and electron microscopy analysing the expression of osteogenic markers: calcium, alkaline phosphatase (AP), osteopontin (OP), bone sialoprotein (BSP) and collagen type 1. We also measured proliferation, AP activity and mRNA expression of AP and osteocalcin (OC). Electron microscopy and Toluidine-blue staining demonstrated that bFGF accelerated (day 20 vs. day 40) and increased mineralization. With bFGF, calcium, OP and BSP were strongly enhanced at day 40, whereas AP decreased. Our in vitro results demonstrate that Hyaff 11 is a useful vehicle for growth, differentiation and mineralization of rat BMSC, and that it permits bone development.

Alkaline Phosphatase↗
PubMed2001

Transplantation of chondrocytes seeded on a hyaluronan derivative (hyaff-11) into cartilage defects in rabbits.

Different methods have been used to improve chondrocyte transplantation for the repair of articular cartilage defects. Several groups of biomaterials have been proposed as support for in vitro cell growth and for in vivo implantation. Here. we describe a new approach investigating the healing of rabbit cartilage by means of autologous chondrocytes seeded on a hyaluronan derivative referred to as Hyaff-11. Full thickness defects were created bilaterally in the weight-bearing surface of the medial femoral condyle of both femora of New Zealand male rabbits. The wounds were then repaired using both chondrocytes seeded on the biomaterial and biomaterial alone. Controls were similarly treated but received either no treatment or implants of the delivery substance. Histologic samples from in and around the defect sites were examined 1, 3 and 6 months after surgery and were scored from 0 to 16. Statistically significant differences in the quality of the regenerated tissue were found between the grafts carried out with biomaterial carrying chondrocyte cells compared to the biomaterial alone or controls. This study demonstrates the efficacy of this hyaluronan-based scaffold for autologous chondrocytes transplantation.

Animals↗
PubMed2001

Biological glass coating on ceramic materials: in vitro evaluation using primary osteoblast cultures from healthy and osteopenic rat bone.

ZrO2 and Al2O3 substrates were successfully coated by a double layer of a silica-based glass named RKKP, using a low-cost firing technique. RKKP is a glass well known for its bioactivity; therefore, a RKKP coating on Al2O3 or ZrO2, allows to combine the excellent mechanical properties of these strong ceramic substrates with its bioactivity. ZrO2 samples were easily coated using a double layer of RKKP by a simple enamelling technique. To accommodate the thermal expansion coefficient mismatch between Al2O3 and RK K P, this substrate was coated using a multilayered composite approach. All of the coatings were characterised from a morphological and compositional point of view, and an extensive biological evaluation was performed using fresh rat osteoblasts. Osteoblast primary cultures were derived from the trabecular bone of femoral condyles harvested from intact (NB) and osteopenic (OB) rats. After characterisation of their phenotype, osteoblasts were seeded on material samples of ZrO2 or Al2O3 coated with RKKP, and cultured for 7 days. Cell proliferation (MTT test) and cell differentiation (alkaline phosphatase activity) were evaluated at the end of the experiment, to assess osteoblast behaviour in the presence of biomaterials and determine if the results were related to the host bone quality. Results of both materials showed a good level of biocompatibility. In particular, MTT significant higher values were detected in NB cultures on ZrO2-RKKP samples; ALP activity significantly increased in NB cultures on Al2O3-RKKP and in OB cultures on both coated samples.

Aluminum Oxide↗
PubMed2001

Haemodynamic and volumetric monitoring during haemorrhagic shock in swine.

Various studies have been performed concerning haemodynamics in the shock state. The aim of this study was to examine if a haemodynamic approach based on volumetric indices can offer a new method of evaluation. Volumetric measurements of ventricular filling and cardiac function were compared with classical haemodynamic variables during induced haemorrhagic shock in swine. Twelve hybrid swine were anaesthetized and underwent arteriectomy to induce haemorrhagic shock. Blood was collected in ACD treated bags and reinfused via the same vein after a shock period of 90 min. Haemodynamic and volume measurements were evaluated. Seven swine survived to complete the protocol and reached the final experimental time (90 min after reinfusion), while the remaining five died 1 h after reinfusion. Concerning the haemodynamics, afterload changes characterized the haemorrhagic shock period, while blood volume distribution dictated ventricular filling and ventricular kinetics during the post-reinfusion period. Systemic vascular resistance was different in the two groups. This study suggests that blood volumetric evaluations can offer better comparative data than pulmonary catheterisation for a precise assessment of cardiac output. Preload values have turned out to be of greater relevance than traditional pressure variables.

Animals↗
PubMed2001

Proton magnetic relaxation in bone marrow related to age and bone mineral density: low-resolution in vitro studies.

Detailed analysis of proton spin-spin and spin-lattice relaxation behaviors of the bone marrow in the presence of trabecular bone network was performed at low-resolution (B(0) = 0.496T) on rat vertebrae specimens deprived of spinal cord. Two groups of samples, from young and old healthy animals, were investigated before cellular necrosis had started. BMD measurements were carried out to quantify the expected age-related modifications of the trabecular bone network. 1H-MR measurements were also performed on the same samples, deprived of marrow and saturated with water, in order to control the validity of a possible interpretation of the marrow 1H-MR characteristics, in terms of marrow components, and to investigate the possible employment of these samples to study the trabecular bone network properties. We pointed out that: 1) a bimodal distribution of T(2i) and T(1i) values (distinguishing "fast" and "slow" relaxations) describes satisfactorily all the 1H-MR experimental decays; 2) age-related modifications of the trabecular bone network are marked by correlate variations of the BMD value and of the proton spin-spin relaxation rates in water saturated samples; 3) age-related modifications of marrow are underlined by variations of the average value of the "fast" T(2i) and of the "slow" T(1i) relaxation time distributions, which could be attributed to the marrow components different from the fat granules of the adipose cells. Our results suggest that studies in vitro on bone tissue, by 1H-MR techniques at low-resolution, may contribute to a better bone function characterization and, therefore, to a better clinical utilization of MRI techniques.

Aging↗
PubMed2001

Calcitonin release system in the treatment of experimental osteoporosis. Histomorphometric evaluation.

Bioabsorbable polyphosphazene matrices charged with 250 microg calcitonin were evaluated as calcitonin delivery systems for the controlled release of this drug in an in vivo experimental model. Matrices were implanted under general anesthesia in osteopenic female rats, while a group of osteopenic animals (control group) received unloaded matrices. After 30 days a second series of matrices, loaded and unloaded was, respectively, implanted in both groups. In a third group of osteopenic female rats (positive control), 10 IU calcitonin were injected daily for two months. A baseline group and a sham operated group of animals were also included in the study. The explanted matrices were histologically evaluated together with the surrounding tissues, and bone histomorphometry was performed on undecalcified sections from femurs. The results showed the good biocompatibility of the matrices. Bone histomorphometry revealed that bone architecture in the treatment group was improved and results were not different from those observed after calcitonin injection. These data confirm a good in vivo behavior of the system, as well as a therapeutic effect of the released calcitonin in the osteopenic condition.

Animals↗
PubMed2001

Laser biostimulation of cartilage: in vitro evaluation.

An in vitro study was performed to evaluate the laser biostimulation effect on cartilage using a new gallium-aluminium-arsenic diode laser. Chondrocyte cultures were derived from rabbit and human cartilage. These cells were exposed to laser treatment for 5 days, using the following parameters: 300 joules, 1 watt, 100 (treatment A) or 300 (treatment B) hertz, pulsating emission for 10 minutes, under a sterile laminar flow. Control cultures (no treatment) received the same treatment with the laser device off. Cell viability was measured by MTT assay at the end of the laser treatment and then after 5 days. Neither rabbit nor human cultured chondrocytes showed any damage under a light microscope and immunostaining control following laser treatment. The MTT test results indicated a positive biostimulation effect on cell proliferation with respect to the control group. The increase in viability of irradiated chondrocytes was maintained for five days following the end of the laser treatment. The results obtained with the Ga-Al-As diode laser using the above tested parameters for in vitro biostimulation of cartilage tissues provide a basis for a rational approach to the experimental and clinical use of this device.

Analysis of Variance↗
PubMed2001

Effect of L-lysine and L-arginine on primary osteoblast cultures from normal and osteopenic rats.

A therapeutic role of amino acids L-lysine (Lys) and L-arginine (Arg) in osteoporosis and fracture healing was demonstrated previously by in vivo studies. In the present study, primary cultures of osteoblasts were used to investigate the effect of amino acids on gene expression (alkaline phosphatase activity, ALP; osteocalcin, OC; type I collagen), nitric oxide production (NO) and proliferation (MTT) of cells. Cells were isolated from the distal femurs of normal and osteopenic rats. Normal and osteopenic bone-derived cells were divided into four groups: control, Lys (0.587 mg/mL/d), Arg (0.625 mg/mL/d), and Lys + Arg (0.587 + 0.625 mg/mL/d). No evidence of differences between normal and osteopenic bone-derived cultures in basal conditions was observed. A significant (P = 0.002) increase of 10.4% in NO production was observed in normal bone-derived osteoblasts treated with Lys + Arg when compared to the control group at 7 days. At the same time, normal bone-derived osteoblasts treated with Arg and Lys + Arg showed significant increases in type I collagen synthesis of 25.3% and 28.4%, respectively, when compared to the control group. Osteopenic bone-derived osteoblasts showed significant (P = 0.002) increases of 27.6% in MTT and 28.7% in cell count at 48 hours when treated with Lys + Arg in comparison with the control group. At 7 days, NO production and type I collagen synthesis increased significantly (P< 0.005) both in osteopenic bone-derived osteoblasts treated with Arg (NO: 18.5%; type I collagen: 34.4%) and Lys + Arg (NO: 23.7%; type I collagen: 20.9%) compared to the control group. Finally, a significant (P = 0.025) decrease of 5.8% in OC level was observed in osteopenic bone-derived osteoblasts treated with Arg. Results suggest that the potential therapeutic effect of Lys and Arg on bone could be related, at least in part, to an improvement of NO production and type I collagen synthesis by osteoblasts both in normal and in osteopenic bone. In osteopenic bone-derived osteoblasts this synthetic phase is preceded by an initial increase of cell proliferation.

Animals↗
PubMed2001

Comparison of calcitonin, alendronate and fluorophosphate effects on ovariectomized rat bone.

The effects of calcitonin, alendronate and fluorophosphate preventive treatment on ovariectomized rat femur were studied by comparing densitometric, mechanical, mineralogical and histomorphometric data. Sixty retired breeder female Sprague-Dawley rats, aged 10 months, were randomly divided into six groups. A group (baseline) was euthanized at the beginning of the study as a baseline group; four groups were ovariectomized and one was sham-operated (sham) and considered as a sham-aged group. A group of ovariectomized rats was used as a sham-therapy control (OVX) and received only deionized drinking water, while the other three received: a) salmon calcitonin (SCN) at a dose of 2 IU/kg/d s.c. (OVX + SCN); b) alendronate sodium salt (ALN) at a dose of 6 microg/kg/d administered by gavage (OVX + ALN); and c) L-glutamine monofluorophosphate (G-MFP) and calcium at a rate of 1:30 F/Ca at a dose of 0.21 mg F/6.30 mg Ca per kg/d by gavage (OVX + MFP). Significant increases (P < 0.05) of about 15 and 27% in femoral proximal epiphysis bone mineral density (BMD) of the OVX + ALN group were observed versus healthy groups and the OVX group, respectively. The OVX + ALN group also showed significant increases in femoral mid-diaphysis BMD when compared to OVX (18%, P < 0.001), OVX + SCN (14%, P < 0.05) and OVX + MFP (18%, P < 0.001) groups. In the OVX + MFP group, the three-point bending test demonstrated significant increases (P < 0.05) in maximal load of 21 and 22% when compared to the OVX and OVX + SCN groups, respectively. Also, stiffness data showed significant increases of the OVX + MFP (17%) and sham (14%) groups in comparison with the OVX group. A decrease in Mg (42%, P < 0.05), and increases in Ca (15%, P < 0.0001) and PO4 (8%, P < 0.005) content were found by comparing OVX + MFP and OVX groups. Trabecular bone volume results showed significant increases by comparing OVX + ALN and OVX groups (12.20%, P < 0.0005), as well as control groups. Tested agents were able to reduce the bone loss due to estrogen deficiency, but this did not always produce an increase in strength of the treated bone. Alendronate treatment prevented a decrease in bone mineral density and maintained bone mechanical properties after ovariectomy without impairment of bone mineralization in aged rats.

Absorptiometry, Photon↗