Biomedical subjects

A Ricci

Publications and source records attributed to A Ricci.

At least 19 recordsLinked to original sources

PubMed2006

Lack of long-range order in confined two-dimensional model colloidal crystals.

We investigate the nature of the ordered phase for a model of colloidal particles confined within a quasi-one-dimensional (Q1D) strip between two parallel boundaries, or walls, separated a distance D in two dimensions (2D). Using Monte Carlo simulations we find that at densities typical of the bulk 2D triangular solid the order in the D1D strip is determined by the nature of the boundaries. While the order is enhanced for a suitably corrugated boundary potential, for a uniformly repulsive smooth boundary potential ordering normal to the walls is enhanced ("layering"), but destroyed parallel to the wall.

Journal Article↗

PubMed2006

Dopamine receptor subtypes in the human pulmonary arterial tree.

Dopamine induces vasorelaxation of pulmonary artery primarily through an endothelium-dependent mechanism, but dopamine receptor subtypes involved in these mechanisms have not been identified yet. The expression and localization of dopamine D1-like (D1 and D5) and D2-like (D2, D3 and D4) receptors were investigated in hilar, lobar and intrapulmonary branches of human pulmonary artery by immunoblotting and immunohistochemistry. Pulmonary artery expresses dopamine D1, D2, D4 and D5 receptor subtypes, but not the D3 receptor subtype. Dopamine D1 and to a lesser extent D5 receptors were accumulated primarily in the endothelium of extrapulmonary branches of pulmonary artery. A faint dopamine D1 and D5 receptor immunoreactivity was found in the inner media of extrapulmonary and of large sized intrapulmonary branches of pulmonary artery, but not in medium- or small-sized intrapulmonary artery branches. Dopamine D2 and to a lesser extent D4 receptor immunoreactivity co-localized with the tyrosine hydroxylase-immunoreactive sympathetic plexus supplying pulmonary artery was found in the adventitia and in the adventitia-media of both extra- and different-sized intrapulmonary branches of pulmonary artery. These findings suggest the possible role of dopamine receptors in the pulmonary endothelium-dependent vasorelaxing activity. The D1 receptor subtype seems to be the most involved in this mechanism. Dopamine D2-like receptors are prejunctional and are located at the level of sympathetic neuroeffector plexus. The heterogeneous distribution and density of dopamine receptor subtypes along the human pulmonary arterial tree may be related to the different functional roles of dopamine at various levels of the pulmonary circulation.

Adolescent↗

PubMed2006

Comparison of Pycnogenol and Daflon in treating chronic venous insufficiency: a prospective, controlled study.

The aim of this study was to investigate the clinical efficacy of oral Pycnogenol (Horphag Research Ltd., UK) in patients with severe chronic venous insufficiency (CVI) in comparison to the combination of diosmin and hesperidin (Daflon, Servier, France). A group of 86 patients with severe chronic venous insufficiency (CVI), venous hypertension, ankle swelling) and previous history of venous ulcerations received either oral Pycnogenol (capsules) 150 mg or 300 mg daily for 8 weeks or Daflon, 1,000 mg/day. All patients completed the study without dropouts. At the end of the study, microcirculatory results indicated: a progressive decrease of skin flux at rest (RF); a significant decrease in capillary filtration (RAS); an improvement in the symptomatic venous score (ASLS); a reduction in edema; a significant improvement (increase) in pO(2) and a decrease in pCO(2) in the Pycnogenol group. A significant level of improvement was reached after 4 weeks of treatment in most patients (p < .05) of the Pycnogenol group while clinical improvement was significant only in 6 subjects in the Daflon group. The positive effects of treatment with Pycnogenol after 8 weeks were significantly larger in comparison with the Daflon group. In conclusion, this study confirms the fast clinical efficacy of Pycnogenol in patients with chronic venous insufficiency and venous microangiopathy and its superiority-considering the evaluated parameters-to the combination of diosmin and hesperidin.

Adult↗

PubMed2006

Diabetic ulcers: microcirculatory improvement and faster healing with pycnogenol.

Diabetic microangiopathy leads to lower limb ulcers that are very slow to heal. Pycnogenol was evaluated on diabetic ulcers in a controlled trial. Ulcer medications were used in 4 groups (30 patients): (1) systemic Pycnogenol and local application; (2) local Pycnogenol only; (3) oral Pycnogenol; and (4) medications only (control group). Ulcerated areas and symptom scores were more reduced with the combined oral and local treatment (P < .05). Oral and local treatment were less effective, but still improved compared with the controls. Combined treatment produced 89% complete healing at 6 weeks versus 84% with local treatment and 85% with oral treatment; healing in controls was 61%. The combined treatment group and oral only group had better microcirculation after the combined treatment. Combined local and systemic application of Pycnogenol may offer a new treatment of diabetic ulcers. Local treatment also speeds ulcer healing.

Diabetes Complications↗

PubMed2006

Every-other-day interferon beta-1b versus once-weekly interferon beta-1a for multiple sclerosis (INCOMIN Trial) II: analysis of MRI responses to treatment and correlation with Nab.

BACKGROUND: In RRMS, clinical exacerbations are usually associated with different types of active lesions at MRI, including: hyperintense lesions on T1-weighted post-gadolinium sequences; new hyperintense lesions or enlarging old lesions on PD/T2-weighted scans; or new hypointense lesions on T1-weighted pre-Gd sequences. OBJECTIVE/METHODS: Primary outcome was the occurrence of patients with at least one active MRI lesion of the different types indicated above during treatment with 250 microg every other day (EOD) interferon beta (IFNbeta)-1b or 30 microg once weekly (OW) IFNbeta-1a in outpatients with RRMS (INCOMIN Trial). RESULTS: The number of patients with at least one 'active' lesion, evaluated over the two-year follow-up, was significantly (P = 0.014) lower in the EOD IFNbeta-1 b arm (1 3/76, 17%) then in the OW IFNbeta-1a arm (25/73, 34%). NAb frequency over two-year follow-up was 22/65 (33.8%) in the EOD IFNbeta-1b arm and 4/62 (6.5%) in the OW IFNbeta-1a arm, significantly greater in the EOD IFNbeta-1b arm. CONCLUSIONS: The development of MRI active lesions is strongly reduced by EOD-IFNbeta-1b compared with OW-IFNbeta-1a, indicating that EOD-IFNbeta-1b is more effective than OW-IFNbeta-1a in reducing ongoing inflammation and demyelination in MS. Logistic regression showed that NAb status did not affect the risk of MRI activity.

Adjuvants, Immunologic↗

PubMed2006

[Open radiofrequency liver resection: technical details].

AIM: Radiofrequency (RF) for the treatment of hepatic neoplasms can be performed through percutaneous, laparoscopic or open surgery. The aim of this study was to point out the details of the role of open RF (ORF). METHODS: Between November 2002 and November 2003, we performed 13 ORFs. Seven patients had an association with chronic liver cirrhosis. With the aid of intraoperative single, internally cooled needle RF, 12 liver resections were performed (7 subsegmentectomies, 3 segmentectomies, 1 left lateral lobectomy, and 1 right lobectomy). In 1 case RF was applied directly to the tumor lesion. In all cases ultrasonography (US) was performed intraoperatively, other lesions were found in 7.7% of the cases. RF energy was applied along the margins of the tumor to create < > before resection with a scalpel. RESULTS: Average operating time for ORF alone was 74.4 minutes (range 30-115 minutes). Mean intraoperative blood loss during the procedure was 104 mL (range 25-250 mL), and blood transfusions were required in 3 patients. Mean hospital stay was 7.9 days (range 6-10 days). Only minor complications were found, and no mortality was observed. No liver recurrence was detected during mean follow-up of 6 months. CONCLUSIONS: This technique is suitable for patients who are at risk of bleeding because it offers a new method for transfusion-free resection, reducing postoperative complications and shorter long-term survival. Adequate follow-up is necessary to judge its true efficacy, in terms of recurrence and survival.

Aged↗

PubMed2005

Minocycline in amyotrophic lateral sclerosis: a pilot study.

Recent studies indicate that minocycline exerts neuroprotective effects in vitro and in vivo, and suggest that the drug may represent a novel therapeutic approach to amyotrophic lateral sclerosis (ALS). In this study we investigated the safety of combined treatment with minocycline and riluzole in ALS. Twenty ALS patients were randomised into two groups and administered either riluzole (50 mg b.i.d.) or riluzole and minocycline (100 mg i.d.) for 6 months. Disease progression was measured by means of the ALS-Functional Rating Scale score at monthly intervals. Respiratory function was measured at the beginning of the study and repeated after 3 and 6 months of treatment. Combined treatment with minocycline and riluzole was not followed by significant side effects. This pilot study shows that minocycline and riluzole can be taken safely together. Further trials are needed to assess efficacy of such treatment.

Anticonvulsants↗

PubMed2005

Prevention of edema in long flights with Pycnogenol.

The aim of this study was to evaluate the prevention of edema during long-haul flights with an oral, anti-edema and antithrombotic agent (Pycnogenol, Horphag, Research Management SA, Geneva, Switzerland) in asymptomatic subjects. The assessment of edema was performed by evaluating an analogue scale, the rate of ankle swelling by strain-gauge derived rate of ankle swelling (RAS), and by assessing the ankle circumference variation. The study included 211 subjects; 169 completed the study (88 in the control group and 81 in the Pycnogenol group). There were no important differences between the two groups (comparable for age, gender, weight, body mass index, and pattern distribution). The edema score, the RAS, and the circumference at inclusion were also comparable. After the flight in those treated with Pycnogenol, the edema score was increased only by 17.9% (vs. an increase of 58.3% in the control group) (p<0.05). The RAS, evaluated in 22 subjects in the Pycnogenol group (age 44.5; SD 8) and in 23 in the control group (age 45; SD 9) was increased on average by 91% in the control group and 36% in the Pycnogenol group (p<0.05). The variation on circumference at the ankle was 6% in the Pycnogenol group (11% in the control group; p<0.05). These results indicate a positive effect of Pycnogenol on edema during long flights when considering subjective and objective data. No unwanted effects were observed.

Adult↗

PubMed2005

Combined endovascular and microsurgical approach in the treatment of giant paraclinoid and vertebrobasilar aneurysms.

AIM: The aim of this study is to present the application of endovascular intraoperative occlusion of the parent artery during the microsurgical treatment of giant paraclinoidal internal carotid artery aneurysms (ICA) and of complex vertebrobasilar junction aneurysms . METHODS: Five cases of giant paraclinoidal ICA aneury-sms were treated by direct surgical approach. In the operatory room any patient underwent angiography and balloon occlusion test using a mobile digital subtraction angiograph. Thereafter the catheter was left in the aortic arch. Through an extended pterional craniotomy, it was possible to evidentiate the aneurismal sac. The proximal control of the vessel was achieved inflating a double-lumen balloon; clipping of the aneurysm was achieved, because of pressure lowering inside the aneurysm. Also a giant vertebrobasilar junction aneurysm was treated by this combined technique: using a posterolateral approach the control of the omolateral vertebral artery was obtained by temporary clipping above PICA's origin; the control of controlateral artery was obtained inflating a balloon introduced through the femoral artery. These combined manoeuvres determined sac deflation, allowing an easier clipping. RESULTS: Aneurysm obliteration was achieved with preservation of the circulation without complications in all cases. CONCLUSIONS: The endovascular procedure allows safer and reliable proximal control of paraclinoidal ICA and vertebral artery during the microsurgical treatment of paraclinoid and vertebrobasilar junction aneurysms.

Angiography, Digital Subtraction↗

PubMed2005

Supratentorial cavernomas in eloquent brain areas: application of neuronavigation and functional MRI in operative planning.

AIM: Cavernomas located in eloquent areas of cerebral hemispheres represent a challenge for the neurosurgeon. An accurate surgical approach is essential to completely remove the lesion with function preservation. Aim of this study was to evaluate the usefulness of integration between standard magnetic resonance imaging (MRI) for neuronavigation and functional MRI (fMRI) in preoperative planning and intraoperative removal of cavernomas. METHODS: Between June 2000 and December 2002, 21 patients underwent surgery for supratentorial subcortical cavernomas. Eleven lesions were located adjacent to eloquent brain areas. All the patients in the series underwent MRI for neuronavigation and, since January 2002, in 6 cases of lesions located in eloquent areas, fMRI was also performed, with subsequent images fusion. The surgical approach was performed via the transgyral route under conventional and ultrasound-guided neuronavigation. RESULTS: All the lesions were totally removed. No morbidity was seen in patients harbouring lesions in non eloquent areas. Four patients with lesions in critical areas suffered transient focal deficits, but only one patient of this series was operated on by the auxilium of image fusion. In 7 patients operated on by conventional image-guided surgery and affected by preoperative seizures, no further seizures were observed after surgery. In 3 patients more hosting lesions neighbouring critical areas, the perilesional ring was not removed, observing persistence of seizures pharmacologically treated. In 4 of the 6 patients (all affected by seizures), operated on by fMRI auxilium, lesion removal was associated to the removal of the perilesional ring. No further epilepsy was seen in these patients. CONCLUSIONS: In all the cases the use of neuronavigation allowed minimally invasive approaches and radical excision of the lesions. Moreover, fMRI seemed to provide important additional information in patients with lesions in eloquent brain areas, allowing a more aggressive approach on the perilesional tissue to the aim of resolving seizures, in absence of an increase in the morbidity rate.

Adolescent↗

PubMed2004

Phage types, ribotypes and tetracycline resistance genes of Salmonella enterica subsp. enterica serovar Typhimurium strains isolated from different origins in Italy.

The tetracycline resistance (tet) gene patterns of 52 tetracycline resistant Salmonella enterica subsp. enterica (S.) serovar Typhimurium isolates collected from animals, food of animal origin, and humans in Italy, were investigated to evaluate whether the tet gene patterns could be used for strain differentiation in addition to phage typing and ribotyping. The detection of tet genes was performed by specific PCR assays. Ribotyping was performed automatically using PvuII as restriction enzyme. Ten different ribotyping patterns were detected. All isolates were positive for at least one of the tet genes studied and six different tet gene patterns were observed. Ribotyping and tet gene patterns showed discriminatory indices of 0.741 and 0.812, respectively. Multiple tet genes were commonly found among tetracycline resistant S. typhimurium isolates from various sources. The resulting tet gene patterns allowed further discrimination of strains which were otherwise indistinguishable by their phage type, ribotype and origin. Thus, the analysis of tet gene patterns might represent an additional tool for the differentiation of S. typhimurium isolates.

Animals↗

PubMed2004

The interhemispheric transcallosal-transversal approach to the lesions of the anterior and middle third ventricle: surgical validity and neuropsychological evaluation of the outcome.

Based on the observation of the course of callosal fibres and of their artero-venous support as appearing in a microanatomic study, the Authors propose a variant of standard callosotomy procedure by the introduction of the transverse section of callosal fibres. This technique would allow the surgeon to spare a larger number of callosal fibres by the combined effect of a lower direct mechanical traction on fibres and a lower impact on artero-venous microcircle. The neuropsychological outcome of the patients who underwent this kind of procedure was evaluated. Fourteen patients affected by occupying-space lesions involving the anterior and middle third ventricle were included in the study. Ten patients underwent transverse callosotomy, four subjects received standard sagittal callosotomy. A control group was also included in the study. All patients underwent a pre-operative and six months post-operative neuropsychological evaluation focused on performance at cognitive and attentional tasks. No disturbances in executive function were observed in either group. Patients receiving transverse callosotomy performed as well as control group subjects in attentive tasks, which is not the case of patients undergoing sagittal callosotomy who show a marked deficit in selective attention for left side visual field. The observed more favourable neuropsychological outcome supports transverse callosotomy as a valid alternative method to standard longitudinal callosotomy in third ventricle surgery.

Adult↗

PubMed2004

Antibiotic resistance in Salmonella enterica serotypes Typhimurium, Enteritidis and Infantis from human infections, foodstuffs and farm animals in Italy.

The antimicrobial susceptibility of isolates of Salmonella enterica serotypes Typhimurium, Enteritidis, and Infantis isolated from humans, foodstuffs and farm animals in Italy between 1999 and 2001 was examined. All the isolates were susceptible to cefotaxime and ciprofloxacin, but high rates of resistance were observed for several other drugs, especially for S. Typhimurium. The rates of resistance and multiresistance were generally higher among animal and food isolates than in human strains; conversely, no significant difference was observed between animal and food isolates. Among S. Typhimurium, multiresistance was more common in bovine, poultry and rabbit strains than in swine isolates, and was rare in strains from pigeon. Resistance to trimethoprim sulphamethoxazole was mainly found in isolates of swine and human origin. This study confirms the role of livestock as a reservoir of drug-resistant Salmonella spp. and underlines the need for integrated surveillance systems of antibiotic resistance that consider isolates not only from human disease but also from the animal reservoirs and the food vehicles.

Animals↗

PubMed2004

Pheno-genotyping of Salmonella enterica serotype Enteritidis isolates identified in Sicily during a reemergence period.

After an upward trend paralleling that occurring in most European countries, including Italy, since October 2002 Salmonella enterica serotype Enteritidis (S. Enteritidis) has again gained the first position among outbreak and sporadic human isolates of Salmonella in Sicily. Because phage typing of S. Enteritidis has many technical and epidemiological limitations and molecular methods have proved to be poorly discriminative for this organism, multiple typing, using phage typing together with pulsed field gel electrophoresis (PFGE) and plasmid profiling on a sample of fifty human and poultry isolates identified during the period October 2002 to May 2003 in Sicily, was chosen as the most valuable strategy to explore key features of this new epidemic wave. Although the limited number of strains imposes a cautious interpretation of the results, an apparently increasing phage type heterogeneity has emerged with rise in PT6 as the more striking event. While PFGE has confirmed the findings by other authors about the close genetic homogeneity between PT4 and PT6, plasmid profiling has provided discriminative patterns for PT6 strains. Combined phenotypic and genotypic profiles are necessary for epidemiological studies and public health investigations on S. enteritidis.

Animals↗

PubMed2004

Prevention of venous thrombosis and thrombophlebitis in long-haul flights with pycnogenol.

The aim of this study was to evaluate the occurrence of deep venous thrombosis (DVT) and superficial vein thrombosis (SVT) and its prophylaxis with an oral anti-edema and antithrombotic agent (Pycnogenol, Horphag, Research Management SA, Geneva, Switzerland) in long-haul flights, in subjects at moderate to high-risk of DVT and SVT. The study pre-included 244 pre-selected subjects; 211 were included (33 were excluded for several reasons due to logistic problems) and 198 completed the study; 13 subjects were lost for follow-up at the end of the flight, all for non-medical problems (i.e., for difficult connections). All subjects were scanned within 90 minutes before the flight and within 2 hours after disembarking. Subjects were supplemented with 100 mg Pycnogenol per capsule. Treatment subjects received two capsules between 2 and 3 hours before flights with 250 mL of water; two capsules were taken 6 hours later with 250 mL of water and one capsule the next day. The control group received comparable placebo at the same intervals. The flight duration was on average 8 hours and 15 minutes (SD 55 min) (range, 7.45-12.33). In the control group there were five thrombotic events (one DVT and four superficial thromboses) while only nonthrombotic, localized phlebitis was observed in the Pycnogenol group (5.15% vs. no events; p<0.025). The ITT (intention to treat) analysis detects 13 failures in the control group (eight lost to follow up + five thrombotic events) of 105 subjects (12.4%) vs. five failures (4.7%; all lost, no thrombotic events) in the treatment group (p<0.025). No unwanted effects were observed. In conclusion, this study indicates that Pycnogenol treatment was effective in decreasing the number of thrombotic events (DVT and SVT) in moderate-to-high risk subjects, during long-haul flights.

Aviation↗

PubMed2003

Immunoglobulin treatment of multiple sclerosis: future prospects.

In one of the most frequent MS demyelination patterns, IgG and complement are demonstrable on myelin surface. It is, probably, an antibody-mediated pattern of myelin damage, usually associated with acute MS, but, at times, observed even in chronic cases. This pattern of myelin damage is extremely similar to that observed in acute demyelinating inflammatory polineuropathies, such as Guillain-Barré syndrome, and in acute disseminated encephalomyelitis (ADEM), a rare demyelinating disease usually occurring after a viral infection or vaccination. These pathologies response well to IgG treatment. Although hyperacute severe cases of MS seem to respond well to IgG treatment, this does not seem the case for other cases of relapses in relapsing-remitting MS. Several trials failed to provide clear evidence of clinical and MRI efficacy of high-dose IgG parenteral treatment in relapsing-remitting multiple sclerosis (MS). The study of Confavreux and the PRIMS study showed that the relapse rate decreases significantly during pregnancy in MS patients, while increases after delivery. IgG is not a cytostatic drug and therefore it has been tested to see whether it reduces relapse occurrence after delivery. In pregnant MS patients treated with high dose, Haas' study and our experience noted a slight increase relapse rate during the six month after delivery but lower than that showed in Confavreux and PRIMS studies in untreated pregnant MS women.

Dose-Response Relationship, Drug↗

PubMed2003

Flight microangiopathy on long-haul flights: prevention of edema and microcirculation alterations with Venoruton.

The aim of this study was the evaluation of the effects of Venoruton (HR) on the prevention and control of flight microangiopathy and edema in subjects with varicose veins flying for more than 7 hours. A group of 80 patients with varicose veins, edema, and initial skin alterations due to chronic venous hypertension were included. Measurements of skin laser Doppler (LDF) resting flux (RF), PO2 and rate of ankle swelling (RAS), were made before and after the flights (within 2 hours before the flights and within 2 hours after the flights). The length of the flights was between 7 and 9 hours; all seats were in coach class. The two groups (treatment and control) were comparable for age and sex distribution. The variation (decrease) in PO2 was significant in both groups. In subjects treated with HR the decrease in PO2 was smaller (p < 0.05). The decrease in LDF-RF was significant in both groups with a higher flux at the end of the flight in the treated subjects (p < 0.05). The venoarteriolar response was decreased at the end of the flights. The decrease was less evident in the treatment group (p < 0.05). The increase in RAS was significant in the control group while it was limited in the HR group. In conclusion, HR is useful for reducing the increased capillary filtration and in controlling edema in patients with chronic venous disease in long-haul flights. HR is effective to control flight microangiopathy associated with edema.

Adult↗

PubMed2003

Prevention of venous thrombosis with elastic stockings during long-haul flights: the LONFLIT 5 JAP study.

The aim of this study was to evaluate deep venous thrombosis (DVT) prophylaxis with specific elastic stockings in long-haul flights (11-13 hours), in high-risk subjects. A group of 300 subjects was included; 76 were excluded for several problems including concomitant treatments; 224 were randomized into two groups (stockings vs. controls) to evaluate prophylaxis with below-knee stockings. An exercise program was used in both groups. Scholl (UK) Flight Socks (14-17 mmHg of pressure at the ankle) were used. DVT was diagnosed with ultrasound scanning. The femoral, popliteal, and tibia] veins were scanned before and within 90 minutes after the flights. Of the 205 included subjects, 102 controls and 103 treated subjects completed the study. Drop-outs were due to flight connection problems. Age, gender, and risk distributions were comparable in the two groups. In the treatment group (103 subjects; mean age, 42; SD 9; M:F, 55:48), one limited, distal DVT was observed (0.97%). In the control group (102 subjects; mean age, 42.1; SD 10.3; M:F, 56:46), six subjects (5.8%) had a DVT. There were no superficial thromboses. The difference in DVT incidence is significant (p<0.0025; six times greater in the control group). Intention-to-treat analysis counts 18 failures in the control group (12 lost to follow-up + six thromboses) of 112 subjects (15.8%) versus eight failures (7.3%) in the treatment group (p<0.05). The tolerability of the stockings was very good and there were no complaints or side effects. All events were asymptomatic. Considering these observations, Scholl Flight Socks are effective in reducing the incidence of DVT in high-risk subjects.

Adult↗