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P Rossi

Publications and source records attributed to P Rossi.

At least 73 records · Page 4Linked to original sources
PubMed2002

PIXE micro-beam mapping of metals in human peri-implant tissues.

Previous investigations did not agree about the possible presence of titanium and other metals in the tissues around endosteal dental implants and joint prostheses. Indeed, while some authors reported diffusion of metals into the tissues, some others did not find evidence of this phenomenon. In the present study, four dental titanium implants, removed with the surrounding tissues from patients at various time intervals after the insertion, were studied by means of the micro-beam proton-induced X-ray emission (PIXE micro-beam) technique, which draws maps showing the tissue distribution of elements with a detection limit of about 1 ppm. One implant was built in commercially pure titanium, two others in titanium coated with titanium plasma spray, and the fourth in Ti-Al-V alloy. Their composition was confirmed by the PIXE micro-beam analyses. The removed samples were embedded in epoxy and processed with a cutting-grinding appliance, mounted on plastic holders, and ground up to a thickness of about 35 microm. Optical microscope examinations were also carried out, to compare the optical findings with the elemental maps obtained with the PIXE micro-beam. One implant, removed after 70 days because the patient had developed peri-implantitis, had some inflammatory soft tissue attached, with no evidence of metal leakage. The other three implants had been removed after 6, 7 and 9 years of valid clinical service, because of the fracture of the prosthetic abutment or the implant stem. At the optical microscope, all these fixtures were embedded in mature bone. The elemental maps indicated small titanium deposits in about 5% of the bone bordering the implants, while aluminum, when present in the fixture, leaked diffusely into the surrounding bone and vanadium was not found in the tissues. These results suggest that titanium may be found occasionally in peri-implantar tissues, but has very little tendency to spread, while the presence of aluminum in the implant alloy may cause an important leakage of this metal.

Journal Article↗
PubMed2002

L-Dopa decreases cutaneous nociceptive inhibition of motor activity in Parkinson's disease.

OBJECTIVES: To estimate changes in motor inhibitory mechanisms at the spinal level in Parkinson's disease (PD) patients by measuring cutaneous silent responses to nociceptive stimuli in the course of L-Dopa therapy. MATERIALS AND METHODS: Fourteen patients with idiopathic PD (Group 1) and 13 patients with other forms of parkinsonism (Group 2) participated in the study. The cutaneous silent period (CSP) from the hand and clinical scores (UPDRS, part III) were measured "off" therapy (T0), after a single dose of L-Dopa (T1) and 3 months after the beginning of L-Dopa daily therapy (T2). RESULTS: At T0 the duration of the CSP was significantly prolonged in Group 1 and Group 2. At T1 and T2 the mean duration of the CSP significantly decreased in Group 1 (P < 0.05) and a significant correlation was found between the shortening of the CSP and the improvement of rigidity and bradikynesia in the upper limb. CONCLUSIONS: Our findings show that L-Dopa decreases the cutaneous nociceptive inhibition of motor activity in PD patients. CSP may be useful to assess L-Dopa responsiveness during the clinical course of PD.

Administration, Oral↗
PubMed2002

Serum leptin and CD4+ T lymphocytes in HIV+ children during highly active antiretroviral therapy.

OBJECTIVE: Because leptin, the adipocyte-derived hormone, affects thymocyte survival, proliferation of naïve T lymphocytes and the production of proinflammatory cytokines, we aimed to investigate the role of this molecule in immunoreconstitution during highly active antiretroviral therapy (HAART). DESIGN: Prospective longitudinal cohort study. A series of 20 HIV+ children were studied. The subjects were grouped by their increase in serum leptin levels after HAART. METHODS: All participants were weight-stable, free of endocrine disorders and opportunistic infections and equally distributed for sex (males, n=10; females, n=10). Body mass index (BMI), serum lipids, leptin, CD4+ T cells and HIV-1 RNA were measured before initiation of HAART and after a 2-year follow-up. RESULTS: Serum leptin concentration positively correlated with CD4+ lymphocyte number before treatment. HAART significantly reduced viraemia and increased serum levels of lipids in all patients, whereas a significant increase in CD4+ cells and serum leptin was observed in the majority of patients. Notably, in children where HAART was not effective in increasing CD4+ lymphocyte counts, serum leptin did not increase. CONCLUSION: To our knowledge, these findings reveal for the first time a novel link among CD4+ T lymphocytes, serum leptin and highly active anteretroviral theraphy.

Antiretroviral Therapy, Highly Active↗
PubMed2002

Restriction in T-cell receptor repertoire in a patient affected by trichothiodystrophy and CD4+ lymphopenia.

Molecular analysis of T-cell receptor (TCR) repertoire, by measuring the CDR3 heterogeneity length of beta-variable regions (spectratyping), is useful for acquiring novel information on the status of immune system in primary immunodeficiency. Here, we evaluate TCR repertoire in a child with trichothiodystrophy (TTD) and combined immunodeficiency (CID). Spectratyping revealed marked alterations of TCR repertoire distribution: 21 and 10 out of 27 TCR Vbeta (TCRBV) families and subfamilies were skewed in CD8+ and CD4+ subsets, respectively. These findings revealed, for the first time in a TTD patient with CID, a marked reduction in the TCR repertoire complexity, which may reflect alterations in the mechanisms regulating the generation and homeostasis of T cells.

ATP-Binding Cassette Transporters↗
PubMed2002

Evidence of clonotypic pattern of T-cell repertoire in synovial fluid of children with juvenile rheumatoid arthritis at the onset of the disease.

Rheumatoid arthritis (RA) and juvenile rheumatoid arthritis (JRA) are characterized by chronic inflammation, synovial cell proliferation and progressive joint damage. It has been speculated that T cells play an important role in the pathogenesis of RA and JRA in the early stage of the disease. Previous studies have demonstrated discrepant results regarding the significance of T-cell clonality in RA or JRA lesions. It can be postulated that the heterogeneity of these data may be linked to the stage of the disease, as the relative importance of selective immunological events is different during the time from onset to established disease. To avoid this problem, we conducted the present study in nine children affected by JRA at the onset of the disease and before treatment. We analysed the T-cell receptor beta chain variable (TCRBV) of CD4+ and CD8+ lymphocytes in peripheral blood (PBL) and synovial fluid (SFL), by a panel of monoclonal antibodies (MoAbs). Furthermore, to assess the clonotypic pattern of T-cell repertoire, the CDR3 length distribution was evaluated by spectratyping analysis. Our results showed no significant expansion of distinct TCRBV subset in either synovial or peripheral compartments. Conversely, when we studied the CDR3 length distribution, an oligoclonal pattern was found in the SFL of six patients, suggesting the presence of a clonotypic restriction of T cells in SFL, which is not detectable in PBL. These findings are consistent with an antigen driven T-cell expansion sequestered at the inflammatory site.

Antibodies, Monoclonal↗
PubMed2002

Statistical analysis of denaturing gel electrophoresis (DGE) fingerprinting patterns.

Technical developments in molecular biology have found extensive applications in the field of microbial ecology. Among these techniques, fingerprinting methods such as denaturing gel electrophoresis (DGE, including the three options: DGGE, TGGE and TTGE) has been applied to environmental samples over this last decade. Microbial ecologists took advantage of this technique, originally developed for the detection of single mutations, for the analysis of whole bacterial communities. However, until recently, the results of these high quality fingerprinting patterns were restricted to a visual interpretation, neglecting the analytical potential of the method in terms of statistical significance and ecological interpretation. A brief recall is presented here about the principles and limitations of DGE fingerprinting analysis, with an emphasis on the need of standardization of the whole analytical process. The main content focuses on statistical strategies for analysing the gel patterns, from single band examination to the analysis of whole fingerprinting profiles. Applying statistical method make the DGE fingerprinting technique a promising tool. Numerous samples can be analysed simultaneously, permitting the monitoring of microbial communities or simply bacterial groups for which occurrence and relative frequency are affected by any environmental parameter. As previously applied in the fields of plant and animal ecology, the use of statistics provides a significant advantage for the non-ambiguous interpretation of the spatial and temporal functioning of microbial communities.

Bacteria↗
PubMed2002

Computationally inexpensive methods for intra-cardiac atrial bipolar electrogram compression.

AIM: This paper reports studies of mathematical algorithms for intra-cardiac atrial bipolar electrogram compression suitable with implementation on implantable devices. PATIENTS AND METHODS: Bipolar intra-cardiac electrograms (IEGMs) of high right atrium were obtained from 20 patients who underwent electrophysiological studies for arrhythmias. Four thousand seven hundred and eighty-two seconds of IEGM were collected and divided into three rhythm groups: sinus rhythm (SR), atrial fibrillation (AF) and atrial flutter (AFL). Since mathematical algorithms suitable for use with implantable devices demand low computational cost, we employed piecemeal linear approximation methods (ZOP--Zero Order Prediction and SAPA--Scan Along Polygonal Approximation), and beat detection method (Peak) both or which need small numbers of operations to perform electrogram compression. Compression ratio (CR) and percent root mean square difference (PRD) were used to compare the three methods, with statistical analyses performed using paired t-test. RESULTS AND CONCLUSION: The best performance was obtained using the Peak method which reaches an average CR of 10.6 in the case of SR group, 2.8 for AF, and 3.6 for AFL groups, respectively, while PRD lies below 2% for SR and AFL groups and 6% for the AF group. Results show that, for bipolar electrograms, the Peak method reaches statistically significant better performance (P<0.001) in all cases except for Peak vs SAPA applied to AF (P=0.2). The number of operations necessary to compress the data indicate that time consumption can be reduced to be suitable for real time compression in implantable devices. The Peak method, which was assumed to receive the instant of occurrence of each recognized beat, from the hardware of the device, requires fewer operations than ZOP and SAPA. Increasing the length of electrograms recorded in pacemakers will enhance the amount of information provided by the implantable device, allowing more detailed characterization of the intra-cardiac activity and leading to new perspectives in arrhythmia diagnosis and therapy.

Adult↗
PubMed2002

[Factors of recurrence of basal cell carcinomas of the eyelid].

UNLABELLED: Basal cell carcinomas of the eyelids can recur, although these recurrences are uncommon. In this retrospective study, all basal cell carcinomas treated at Reims Regional Hospital since 1985 were studied to determine the frequency of recurrence and the factors for recurrence. MATERIAL: and methods: All basal cell carcinomas treated at Reims Regional Hospital since 1985 were studied. A total of more than 200 patients had been operated on for basal cell carcinoma during this period. Those with orbital extension or a location on 2 eyelids were excluded. Epidemiological factors such as sex, age, tumor location, tumor size, and treatment were noted. Recurrences were uncommon, presenting in ten patients. These recurrences were studied in relation to the existing epidemiological data and the treatment provided, particularly the histological results. DISCUSSION: Basal cell carcinomas located on only 1 eyelid or 1 canthus can usually be treated with one surgical intervention. Extemporaneous histological study can preclude a local recurrence in most cases, but in some cases the condition may recur some years later. Factors favoring recurrence are difficult to determine. CONCLUSION: The authors report the number of recurrences after surgical treatment of basal cell carcinomas of the eyelids. The recurrences are relatively uncommon when the treatment has been done with extemporaneous histological examination of the resected edges. These recurrences arise particularly in relatively young patients with no other obvious risk factor.

Basal Cell Carcinoma↗
PubMed2002

Interventional radiology techniques in the treatment of complications due to videolaparoscopic cholecystectomy.

INTRODUCTION: The development of videolaparoscopic cholecystectomy (VLC) has represented an important achievement in the search for minimally invasive surgical procedures, and especially in the surgical management of such a common and costly disease as cholelithiasis. However, the literature shows that, while VLC carries a similar mortality rate to open surgery, it has a greater incidence (2-5 times) of iatrogenic injury to the biliary tract and hepatic hilum [3, 5, 10, 25, 28]; this incidence further increases in cases of so-called "hard cholecystis" [10, 13, 25, 28, 30]. An equally minimally invasive technique is therefore needed to treat these lesions; this technique should be effective and safe, allow for shorter hospital stays and lower costs, and be made available at all the centres where VLC is performed. MATERIAL AND METHODS: We evaluated 60 patients (28 women and 22 men, age range 41-71) with 24 peritoneal collections (14 bilomas, 10 abscesses), 35 biliary stenosis (clips, chronic-developing lesions), and 2 vascular lesions as direct iatrogenic post-LC injuries. The most frequent clinical symptoms were jaundice, pain, sepsis, abdominal distension, and abdominal colic due to retained common bile duct stones. We carried out 60 percutaneous biliary reconstruction procedures, 44 biliary drainages (4 internal, 4 external), 6 combined radiological-endoscopic approaches with the Rendez-Vous technique, and 2 embolisations. RESULTS: All procedures had 100% technical success; the biliary reconstruction procedures had a 2% morbidity rate (sepsis, cholangitis). The clinical emergencies (choleperitoneum, haemoperitoneum, severe jaundice) resolved in 72 hours for 55 of the 60 patients (92%). The combined percutaneous-endoscopic procedures with the biliary Rendez-Vous technique were successfully performed in 5 out of 6 cases, allowing reconstruction of bile duct continuity and remission of symptoms, without the need to resort to surgical anastomosis. At a recent follow-up of the patients who had been managed only percutaneously, one showed patency of the bile ducts and had the stent removed after 18 months, and two showed optimal functioning of the stent that was still in place after 5 and 8 months respectively; two patients were lost to follow-up. Primary biliary patency at 60 months from biliary reconstruction was 75%. Maximum and immediate dilatation was obtained at the first attempt in most cases. Reoperation was avoided in 59 out of 60 patients. Only one patient with full transection of the common bile duct was reoperated on after insertion of a biliary drainage catheter. The overall length of hospital stays was between 1 and 4 weeks. CONCLUSIONS: Interventional radiology carried out according to indications seems to be the most natural way to treat the complications of VLC. It spares the patients, who opted for a minimally invasive technique like VLC, the need to undergo open surgery, and allows for shorter hospital stays and more efficient cost management for the hospital.

Adult↗
PubMed2002

[Severe aortic valve stenosis and coronary disease in the elderly. Epidemiology and hemodynamic features].

BACKGROUND: Aortic valve replacement is an effective and safe intervention in the elderly, but to-day the prevalence of coronary artery disease in the elderly has still to be clarified. Aim of this paper is to analyze in a retrospective study the epidemiology and the hemodynamic relation of the association of severe aortic valve stenosis with coronary artery disease in patients over 75 years. METHODS: In a retrospective study of 12.000 cardiac catheterization procedures, patients with severe aortic valve stenosis were selected: the patients over 75 years (30 patients) were screened for presence/absence of coronary lesion forming two groups: correlations with anatomic and hemodynamic variables were made. RESULTS: 36.6% (11 patients) of the over-75 had significative coronary lesions; the coronary arteries involved were the anterior descendent coronary artery and the right coronary artery; no significative differences were found as to risk factors between the two groups except hypertension; the greater number of calcifications and mitral and aortic regurgitation was found in patients with coronary disease; the values of ejection fraction and cardiac index were significantly smaller in patients with coronary disease. CONCLUSIONS: In patients over 75 the severe aortic valve stenosis is frequently associated with coronary disease and the association is greater than in younger persons; some particular features confirm the elderly patients as a class at particular risk in which coronary angiography and combined bypass graft and valve replacement are of primary importance for the outcomes.

Aged↗
PubMed2002

Allintoshius bioccai n. sp. (Nematoda), a parasite of the bat Eptesicus furinalis from Paraguay, and new data on A. parallintoshius (Araujo, 1940).

A new species of parasitic nematode (Nematoda: Trichostrongylina, Heligmosomoidea) Allintoshius bioccai n. sp., found in the small intestine of the vespertilionid bat Eptesicus furinalis from Paraguay, is described. The new species can be differentiated from A. urumiac (Freitas and Mendonça, 1960) by the absence of vulvar spines in females, and from A. nudicaudus (Freitas and Mendonça, 1963) by the shape of the spicules and the dorsal ray of the copulatory bursa. New data on the morphology and distribution of Allintoshius parallintoshius (Araujo, 1940) are also reported. E. furinalis, Myotis albescens and M. riparius are recorded as new hosts for this species. A key for the identification of the species belonging to the genus Allintoshius is also given.

Animals↗
PubMed2002

[Malignant fibrous histiocytoma of the eyelid].

Fibrous histiocytomas, mostly benign, have often been reported in the orbit, but only four lesions have been described on the eyelids, with only one malignant. The authors present a case of malignant fibrous histiocytoma of the eyelid in a 76-year-old woman with a difficult histological diagnosis. Characteristics of this pathology are explained from data in the literature.

Aged↗
PubMed2002

Systemic capillary leak syndrome. Case report.

We here report the case of a patient with systemic capillary leak syndrome (SCLS). This syndrome is a rare condition characterized by recurrent episodes of hypotension with hemoconcentration and hypoproteinemia. It is due to unexplained episodic capillary hyperpermeabilty that results in fluid and protein shift from the intravascular to the interstitial space: generalized edema, shock and renal failure follow. A 59 yo man was admitted to our intensive care unit because of unexplained shock with hemoconcentration, renal failure, and metabolic acidosis. Previous attemps to reverse shock in a medical ward with crystalloids and dopamine failed. An abdominal CT scan, a TEE, and chest X ray study were inconclusive. No sign or history of major infections or anaphylaxis were present. The patient was resuscitated with massive fluid infusions and norepinephrine on the guide of a Swan Ganz catheter. The diagnosis was made on the basis of a previous episode of severe shock complicated with renal failure and a compartment syndrome, the hemoconcentration, and the negative cardiopulmonary findings. A small amount of monoclonal immunoglobulin G, kappa chain, found in the serum confirmed the diagnosis. The SCLS should be considered in the differential diagnosis of idiopathic and anaphylactic shock. Patients may benefit from a prophylactic treatment with theophilline and terbutaline.

Capillary Leak Syndrome↗
PubMed2001

Addition of small molecules by Zn(II) and Cu(II) dinuclear complexes obtained by an amino-phenolic ligand. Crystal structures of the dinuclear zinc complex assembling butanolate and azide anions.

The coordination properties of the ligand 2,6-bis-[[bis-(2-aminoethyl)-amino]methyl]-phenol (L) toward the zinc ion were determined by means of potentiometric measurements in aqueous solution (298.1 +/- 0.1 K, I = 0.15 mol dm(-3)). L forms mono- and dinuclear complexes with zinc; the stable dinuclear complexes are practically the only existing species using L/Zn(II), molar ratio of 1:2. In these species, each dien subunit binds one zinc ion, while the phenolate moiety bound to both ions allows the two metal centers to be in close proximity with an incomplete coordination environment. The role of this metal-metal distance in binding secondary ligands was investigated for the dinuclear systems 2Zn/L and 2Cu/L by potentiometric (298.1 +/- 0.1 K, I = 0.15 mol dm(-3)) and NMR experiments in aqueous and methanol solution with a series of small guests having nitrogen donor atoms. The coordination sphere of the two metals was completed by adding 1 equiv of only those guests, which showed at least two contiguous donor atoms or two lone pairs on the same atom, to exactly fit the metal-metal distance without modifying the metal cluster. To do this, the imidazole molecule which shows the highest addition constants to the [M(2)H(-1)L](3+) species probably forms a mu-1,1-amino. These results are in agreement with the two crystal structures reported herein [Zn(2)(H(-1)L)(CH(3)CH(2)CH(2)CH(2)O)](ClO(4))(2) (space group P2(1)nb, a = 11.483(5), b = 14.166(5), c = 18.279(5) A, V = 2973(19) A(3), Z = 4, R = = 0.0701, wR2 = 0.1611) and [Zn(2)(H(-1)L)N(3)](ClO(4))(2) (space group C 2/c, a = 14.460(3), b = 12.814(3), c = 14.875(3) A, beta = 105.35(2) degrees, V = 2658(10) A(3), Z = 4, R = 0.0783, wR2 = 0.1806). In fact, these structures display a butanolate or azide guest linked to both Zn(II) ions of the dinuclear complex, resulting in a mu-1,1-oxo and mu-1,1-azido bridge, respectively.

Journal Article↗
PubMed2001

Kinetics of the T-cell receptor CD4 and CD8 V beta repertoire in HIV-1 vertically infected infants early treated with HAART.

OBJECTIVES: To determine the kinetics and the relationship between the T-cell receptor V beta (TCRBV) complementary determining region 3 length, the CD4 T-cell count and HIV viral load changes in HIV-1 infected infants treated early with highly active antiretroviral therapy (HAART) during 1 year of follow-up. DESIGN: Two HIV-1 vertically infected infants, two HIV-1 vertically exposed uninfected and two healthy controls were analysed by spectratyping. Evaluation of viral load, CD4 naive and memory cell counts and a proliferation test were also carried out. METHODS: Twenty-six families and subfamilies of the TCR on CD4 and CD8 T cells were analyzed by spectratyping. Flow cytometric analysis on peripheral blood mononuclear cells for CD4CD45Ra, CD4CD45Ro, CD8CD38, proliferation tests and plasma viral load measurements were performed at baseline, 1, 6 and after 12 months of therapy. RESULTS: HAART induced a marked reduction of viral load in both HIV-1 infected infants and an increase to normal CD4 T-cell count in the symptomatic infant. At baseline the TCRBV family distribution in the majority of CD8 and a few of the CD4 T cells was highly perturbed, with several TCRBV families showing a monoclonal/oligoclonal distribution. During HAART a normalization of the TCR repertoire in both CD8 and CD4 subsets occurred. TCR repertoire normalization was associated with a good virological and immunological response. CONCLUSION: These results suggest that complete and early virus replication control as a result of early HAART leads to a marked reduction of T-cell oligoclonality and is an essential prerequisite to the development of a polyclonal immune response in HIV-1 infected infants.

Antiretroviral Therapy, Highly Active↗
PubMed2001

Length variation of glycoprotein 120 V2 region in relation to biological phenotypes and coreceptor usage of primary HIV type 1 isolates.

Conflicting data have been published concerning the correlation between the length of the second variable region (V2) in the HIV-1 envelope and the biological phenotype of the virus. Here the V2 region length of primary HIV-1 isolates was compared with biological phenotype and coreceptor usage. The V2 region variation was determined by DNA fragment length analysis, virus biological phenotype by the MT-2 cell assay, and coreceptor usage by infection of U87.CD4 cells expressing CCR3, CCR5, or CXCR4. Ninety-three primary virus isolates from 40 patients were analyzed. This panel of viruses included sequential isolates obtained from patients who progressed to AIDS with or without a virus phenotypic switch. We found that NSI MT-2-negative isolates had significantly shorter V2 regions than SI MT-2-positive isolates. However, when V2 region lengths of viruses were analyzed in more detail, we observed that NSI isolates obtained from patients shortly before the phenotypic switch had V2 region lengths similar to those of SI isolates. V2 regions of NSI isolates obtained from patients who progressed to AIDS without a virus phenotypic switch had, in contrast, shorter V2 region than isolates obtained just before virus phenotypic switch. Coreceptor analysis revealed that CCR5-using (R5) isolates generally had shorter V2 regions than virus isolates with the ability to enter CXCR4-expressing cells. Moreover, no significant difference in V2 region length was observed between monotropic SI isolates, that is, X4 isolates, and multitropic SI isolates, that is, R3R5X4 or R5X4 isolates. Thus, we conclude that R5 NSI isolates obtained from patients with stable virus phenotype through the whole disease course display shorter V2 regions than isolates obtained from patients at switch of virus phenotype, suggesting that V2 region length may influence virus coreceptor usage.

Adult↗
PubMed2001

Crossover phenomena in spin models with medium-range interactions and self-avoiding walks with medium-range jumps.

We study crossover phenomena in a model of self-avoiding walks with medium-range jumps, which corresponds to the limit N-->0 of an N-vector spin system with medium-range interactions. In particular, we consider the critical crossover limit that interpolates between the Gaussian and the Wilson-Fisher fixed point. The corresponding crossover functions are computed by using field-theoretical methods and an appropriate mean-field expansion. The critical crossover limit is accurately studied by numerical Monte Carlo simulations, which are much more efficient for walk models than for spin systems. Monte Carlo data are compared with the field-theoretical predictions for the critical crossover functions, finding good agreement. We also verify the predictions for the scaling behavior of the leading nonuniversal corrections. We determine phenomenological parametrizations that are exact in the critical crossover limit, have the correct scaling behavior for the leading correction, and describe the nonuniversal crossover behavior of our data for any finite range.

Journal Article↗