Biomedical subjects

C Trevisan

Publications and source records attributed to C Trevisan.

At least 19 recordsLinked to original sources

PubMed2004

Evaluation of an ambulatory system for gait analysis in hip osteoarthritis and after total hip replacement.

Spatial and temporal parameters of gait have clinical relevance in the assessment of motor pathologies, particularly in orthopaedics. A new gait analysis system is proposed which consists of (a) an ambulatory device (Physilog) including a set of miniature gyroscopes and a portable datalogger, and (b) an algorithm for gait analysis. The aim of this study was the validation of this system, for accuracy and clinical applicability. Eleven patients with coxarthrosis, eight patients with total hip arthroplasty and nine control subjects were studied using this portable system and also a reference motion analyzer and force plate. The small differences in the stance period (19 +/- ms), stride length and velocity (0.4 +/- 9.6 cm and 2.5 +/- 8.3 cm/s, respectively), as well as thigh and shank rotations (2.4 +/- 4.3 degrees and 0.3 +/- 3.3 degrees, respectively), confirmed good agreement of the proposed system with the reference system. In addition, nearly the same accuracy was obtained for all three groups. Gait analysis based on Physilog was also in agreement with their Harris Hip Scores (HHS): the subjects with lower scores had a greater limp, a slower walking speed and a shorter stride. This ambulatory gait analysis system provides an easy, reproducible and objective method of quantifying changes in gait after joint replacement surgery for coxarthrosis.

Aged↗

PubMed2002

Bone loss and recovery in regional migratory osteoporosis.

Regional migratory osteoporosis (RMO) is a migrating arthralgia of the weight-bearing joints of the lower limb associated with focal osteoporosis. Little information is available on a quantitative assessment of systemic or local osteoporosis. In this study, we report three cases of RMO in which spine, hip and whole body serial assessments of bone mass have been evaluated to outline their extent and time course of changes. Systemic osteoporosis, with a prevalent involvement of the mainly trabecular skeletal sites, was present in all the patients, with T-scores below -2.5 at both the lumbar spine and femoral neck. Bone loss in acute episodes ranged from -75.5% to -14.7% and appeared related to the severity of the episode. In acute episodes the demineralizing process affected the whole limb from the hemipelvis to the foot: the bone loss ranged from -33.6% to -3.5% at sites with prevalent trabecular composition and from -19.1% to -1.1% at sites with prevalent cortical composition. Bone recovery was complete in one episode out of six. In the other five cases, the average residual bone loss was 26% (range 13.9-32.7%). Our observations suggest that RMO occurs in subjects with systemic osteoporosis and densitometric assessment may aid in the clinical management.

Acute Disease↗

PubMed2002

Regional migratory osteoporosis: a pathogenetic hypothesis based on three cases and a review of the literature.

Regional migratory osteoporosis (RMO) is a migrating arthralgia of the weight-bearing joints of the lower limb which mainly affects middle-aged males. Its aetiology is unknown. The association of RMO with generalised osteoporosis has recently been reported. A concurrent systemic osteoporosis was also reported in some cases of transient osteoporosis of the hip (TOH), a disorder closely related to RMO. In its turn, TOH is considered a reversible stage of avascular necrosis of the hip (AVN), and the aetiopathogenesis of both of them remains strongly debated. We report three cases of RMO associated with generalised severe idiopathic osteoporosis. Three men, in the fourth and fifth decades of life, complained of at least four episodes of arthralgia in the lower limbs, with a migratory pattern, radiographic focal osteoporosis and final clinical resolution. The most striking common feature of these patients was the presence of a severe systemic osteoporosis with a prevailing trabecular involvement. We suggest that a prolonged or exaggerated activation of regional acceleratory phenomena (RAP) is the cause of transient osteoporosis. Bone tissue microdamage due to osteoporosis may be the most frequent noxious stimulus that turns RAP on, and, bone tissue microfracture is the most prevalent consequence. When this pathogenetic pathway is activated, the progression from focal osteoporosis and bone marrow oedema to avascular necrosis is associated with the amount of structural damage.

Adult↗

PubMed2000

Different mutations in the LMNA gene cause autosomal dominant and autosomal recessive Emery-Dreifuss muscular dystrophy.

Emery-Dreifuss muscular dystrophy (EMD) is a condition characterized by the clinical triad of early-onset contractures, progressive weakness in humeroperoneal muscles, and cardiomyopathy with conduction block. The disease was described for the first time as an X-linked muscular dystrophy, but autosomal dominant and autosomal recessive forms were reported. The genes for X-linked EMD and autosomal dominant EMD (AD-EMD) were identified. We report here that heterozygote mutations in LMNA, the gene for AD-EMD, may cause diverse phenotypes ranging from typical EMD to no phenotypic effect. Our results show that LMNA mutations are also responsible for the recessive form of the disease. Our results give further support to the notion that different genetic forms of EMD have a common pathophysiological background. The distribution of the mutations in AD-EMD patients (in the tail and in the 2A rod domain) suggests that unique interactions between lamin A/C and other nuclear components exist that have an important role in cardiac and skeletal muscle function.

Adolescent↗

PubMed1999

Aberrant expression of CD27 and soluble CD27 (sCD27) in HIV infection and in AIDS-associated lymphoma.

CD27 is a member of the tumor necrosis factor receptor superfamily that is expressed primarily on T cells, as well as on subsets of B cells and NK cells. CD70, which is expressed on activated B and T cells, but not on resting lymphocytes, is a ligand for CD27. Cell surface CD27 can be proteolytically cleaved to produce a 32-kDa soluble CD27 (sCD27) molecule. Elevated levels of sCD27 are seen in a number of disease states and malignancies. Although it has been reported that cerebrospinal fluid sCD27 levels were elevated in people who had AIDS dementia, little is known about CD27 expression in HIV disease. To determine if sCD27 levels were elevated in those with HIV infection, and/or in those with AIDS-associated non-Hodgkin's lymphoma (AIDS-NHL), sCD27 levels were measured in HIV-negative and HIV-positive subjects as well as in people who developed AIDS-NHL. Serum sCD27 levels were seen to be elevated in HIV+ subjects. Furthermore, sCD27 levels were particularly elevated in those subjects who went on to develop AIDS-NHL, with serum sCD27 levels in AIDS-NHL subjects being significantly higher than those in HIV+ subjects who did not develop lymphoma. Most AIDS-NHL cell lines and primary AIDS-NHL tumor specimens expressed both CD27 and its ligand, CD70. The proportion of circulating B cells that expressed cell surface CD27 was substantially reduced in those with HIV infection, and B cells from HIV-infected subjects produced decreased levels of sCD27 in culture. Together, these results indicate that CD27/sCD27 expression is abnormal in HIV infection and suggest that this molecule merits further examination as a potential marker for AIDS-NHL.

Antigens, CD↗

PubMed1999

Alterations of the retino-cortical conduction in patients affected by classical congenital muscular dystrophy (CI-CMD) with merosin deficiency.

Immunocytochemical analysis of the laminin alpha-2 (merosin) chain in the muscle of patients with Classic Congenital Muscular Dystrophy (Cl-CMD) differentiates the types of the disease associated with a merosin deficit from those that are merosin positive. Patients with Central Nervous System involvement in merosin negative Cl-CMD always present alterations of the white matter at RMI, but usually these are not clinically significant. While ocular malformations (microphthalmia, alterations of the anterior chamber, of the retina, or of the angle and cataract) and damage to the Central Nervous System are described in some subtypes of CMD (Muscle Eye Brain disease, Walker Warburg Syndrome), ocular involvement and retino-cortical conduction in merosin negative Cl-CMD are not well known. This study reports on four patients affected by merosin negative Cl-CMD. All these patients presented important alterations of the white matter associated with ventricular enlargement and, in one case, with pachygyria and micropolygyria. Refraction, visual acuity, ocular motility, anterior segment and fundus were examined. ERG Maximal, Cone and Rod response, VEP transient pattern reversal was carried out as well. Significant alterations at the standard ophthalmologic examination or of the electroretinogram responses were not registered while, in all cases, important modifications in retino cortical conduction (reduction in amplitude, increase in latency, reduction in amplitude on the lateral derivations) were observed, demonstrating involvement of the optic pathway at different levels during the course of this disease.

Adolescent↗

PubMed1999

Neuroaxonal dystrophy with dystonia and pallidal involvement.

Infantile neuroaxonal dystrophy (INAD) is an autosomal recessive disease of infantile onset, characterised by progressive clinical course, multi-systemic involvement and widespread presence of dystrophic axons in both the central and peripheral nervous system. Clinical, neurophysiological and neuroradiological criteria of the disease are established, but the occurrence of atypical cases is known. Since the availability of molecular markers is still lacking, diagnostic evidence in vivo is provided by the presence of specific axonal lesions distally in the peripheral nerve fibres. In two children who had a protracted course of the disease with dystonic postures of the upper limbs and showed dystrophic axons following sural nerve biopsy, bilateral pallidal hypointensity was observed after T2-weighted MRI scans. These findings are consistent with iron deposition, and are usually observed in Hallervorden-Spatz syndrome (HSS), a condition which is also characterised by dystrophic axons diffusely present in the central nervous system, but without peripheral nervous system involvement. These observations raise the issue of different phenotypes of INAD, and are consistent with the existence of intermediate forms between INAD and HSS. Altered mechanisms of iron storage and transport to and from the cellular compartments may play a role in the pathogenesis of the disease.

Axons↗

PubMed1998

Graft-tunnel mismatch in endoscopic anterior cruciate ligament reconstruction. Intraoperative and cadaver measurement of the intra-articular graft length and the length of the patellar tendon.

The results of a study conducted on 50 knees endoscopically reconstructed for an anterior cruciate ligament (ACL) lesion with a free bone-patellar tendon-bone graft and 9 cadaver knees are reported. The mean lengths of the patellar tendon (45.48 +/- 4.71 mm) and intra-articular ACL graft (20.44 +/- 1.98 mm) were measured in the operated knees. The mean length of the tibial bone tunnel (51.62 +/- 2.60 mm) was also measured with a tibial guide at 55 degrees. No statistically significant correlation was found between these three measurements. The length of the patellar tendon was weakly correlated with body height. Measurement of the tibial tunnel on the cadaver knees with increasing degrees of inclination revealed a mean length increase of 0.68 mm per degree (confidence limits: 0.49-0.86). Comparison between the tunnel lengths obtained with the guide and those measured with a Kirschner wire showed a mean difference of 2.3 mm. It is thus desirable to make the tunnel about 53 mm long to ensure excellent fixation of a 28 mm bone block with a 25 mm interference screw. Correct measurement of the anatomical structures involved is in any event an essential requirement for proper execution of the surgical technique.

Adolescent↗

PubMed1998

Bone assessment after total knee arthroplasty by dual-energy X-ray absorptiometry: analysis protocol and reproducibility.

Bone quality is important for the success of joint prostheses implantation, and the assessment of bone density after total knee arthroplasty by means of dual-energy X-ray absorptiometry may be useful for monitoring implant stability. The aim of this study is to suggest a validated analysis protocol for the assessment of bone status after total knee arthroplasty. A dedicated densitometric analysis protocol of five regions of interest was designed, and 10 subjects who had received an uncemented knee prosthesis (8 females and 2 males, aged 55-74 years) underwent three consecutive scans in posteroanterior and lateral projections, with repositioning after each scan to test the suitability and reproducibility of the protocol. The reproducibility of the measurement of bone mineral content and density in the femoral and tibial regions ranged, respectively, from 2.1% to 4.1%, from 0.9% to 2.6% for the posteroanterior scans, and from 2.7% to 5.6% and from 2.3% to 4.7% for the lateral scans, depending on the considered region. Our results confirm that the suggested protocol allows precise assessment of bone mineral content and density, and that dual-energy X-ray absorptiometry is reliable for the evaluation of bone mass around prosthetic implants.

Absorptiometry, Photon↗

PubMed1998

In vivo single voxel 1H MRS of glial brain tumors: correlation with tissue histology and in vitro MRS.

Eighteen patients affected by glial brain tumors were examined by localized single voxel magnetic resonance spectroscopy (1H MRS). For all patients histological diagnosis was obtained after stereotactic biopsy or surgical removal of the tumor. Histological nuclear atypia, tumor cellularity, necrosis, vascular proliferation and percentage of Ki-67 positive cells in the total cell populations were evaluated. It was found that some of the in vivo 1H MRS parameters were related to the histological features of the tumor. In particular, the Choi/Cri metabolite ratio obtained from the neoplastic tissues paralleled the Ki-67 cell proliferation index. For some of the patients 1H and 13C in vitro high resolution magnetic spectroscopy of surgical specimens was also carried out. 1H MRS of aqueous extracts from different biopsy specimens of the same tumor furnished fine biochemical information on intratumor heterogeneity. The degree of histological vascular proliferation of the tumor was correlated to the presence of cholesteryl esters in the 13C spectrum of the lipid fraction of surgical specimens.

Adult↗

PubMed1997

Localised proton MR spectroscopy of brain metabolism changes in vegetative patients.

We examined 14 vegetative brain-injured patients with proton magnetic resonance single-volume spectroscopy (1H MRS) at 1.5 T to establish whether there were changes in relative concentrations of N-acetyl aspartate (NAA), choline (Cho) and creatine (CR) metabolites from those found in healthy brains. Spectra were obtained from two different (2 x 2 x 2 cm) volumes of interest in the left and in the right frontal cortex, normal on MRI. All spectra revealed abnormalities compared with normal spectra obtained from age-matched control subjects. Values outside the normal range for at least one of the metabolite ratios were observed in all patients. Cho/Cr was markedly higher and NAA/Cho and NAA/Cr were markedly lower than in the control subjects. At different times six patients regained awareness and the ability to obey commands, and four were re-examined; changes in metabolite ratios were observed, which were different in individual patients. The NAA/Cho ratio reaches statistical significance in discriminating between the patients with a poor outcome (death or prolonged vegetative state) and those who regained awareness; the dividing line appears to be at a value of about 1.6.

Adolescent↗

PubMed1997

Oncocytic meningioma.

Six cases of meningioma showing oncocytic changes are described. The lesions were composed mostly of sheets, nests, and cords of large polygonal cells with finely granular eosinophilic cytoplasm rich in mitochondria. Neoplastic cells showed nuclear pleomorphism with prominent nucleoli. Necrosis and high mitotic rate were present in the majority of cases. Oncocytic differentiation was demonstrated by conventional histology, immunocytochemistry, electron microscopy, and Western-blot analysis. Oncocytic meningiomas showed an aggressive behavior; recurrences were observed in three cases, and invasion of brain cortex was evident in other two cases.

Adenoma, Oxyphilic↗

PubMed1997

Periprosthetic bone density around fully hydroxyapatite coated femoral stem.

In this study, periprosthetic bone mineral density was measured at scheduled time intervals after surgery by dual energy x-ray absorptiometry in 21 patients to assess the history of bone density redistribution after femoral stem insertion. Measurements of changes in bone density with time were obtained for the regions of the greater trochanter, the lateral cortex, the tip, the medial cortex, and the calcar. In all regions, bone density decreased during the first 3 months after surgery; this was followed by a prolonged period of 18 to 30 months of bone gain, a subsequent period of steady state, and the final resumption of bone aging processes after the third postoperative year. The greatest loss was observed in the calcar region after 6 months (greater than 50%). The characteristic pattern of time related bone density changes obtained in this study may make it possible to compare other pathologic, design, or stiffness related patterns. This could have clinical relevance in the early diagnosis of pathologic processes and as a means of evaluating prosthetic designs.

Absorptiometry, Photon↗

PubMed1997

Brain perfusion SPET and proton magnetic resonance spectroscopy in the evaluation of two systemic lupus erythematosus patients with mild neuropsychiatric manifestations.

The diagnosis of central nervous system (CNS) involvement appears to be a major problem in systemic lupus erythematosus (SLE), especially when the clinical signs are non-specific or neuroimaging is unremarkable. Two SLE patients with mild neuropsychiatric manifestations were studied with magnetic resonance imaging (MRI), single photon emission tomography (SPET) and localized proton magnetic resonance spectroscopy (H-1 MRS). MRI was normal in both patients. SPET revealed areas of hypoperfusion in both patients. H-1 MRS demonstrated metabolic abnormalities in the regions corresponding to the hypoperfused areas. A correlation between H-1 MRS and SPET was noted: patients with mild neuropsychiatric SLE may have disturbances evident on SPET and H-1 MRS in the presence of normal anatomy on MRI, suggesting that CNS involvement in SLE has very strong physiological and neurometabolic components in individual patients.

Adult↗

PubMed1995

Magnetic resonance imaging versus arthroscopy for the investigation of the osteochondral humeral defect in anterior shoulder instability. A double-blind prospective study.

A double-blind prospective study was done with 15 patients with anterior shoulder instability to determine the diagnostic efficacy of magnetic resonance (MR) imaging versus arthroscopy in the evaluation of chondral or osteochondral lesions of the humeral head. MR produced 6 true positives, 5 true negatives and 4 false negatives, and its accuracy and sensitivity were 60% and 87%, respectively, whereas arthroscopy gave 8 true positives, 5 true negatives and 2 false negatives, with a sensitivity of 80% and an accuracy of 87%. All lesions diagnosed with either method were regarded as positive by definition, with the result that the specificity was always 100%. The differences in diagnosis sprang from the false negatives. The 40% discrepancy between the two methods was probably due to our distinction in MR between intra- and extra-articular osteochondral lesions. In the first group (the 4 MR false negatives), there were three instances of first-degree intra-articular lesion and one diagnostic error (third-degree lesion). In the second (the 2 arthroscopy false negatives), the lesions were of the extra-articular type. It is thus advisable to employ both of these methods to ensure the correct diagnosis of a Hill-Sachs lesion, and hence the correct choice of treatment.

Adolescent↗

PubMed1994

Comparison of "catheter" and conventional arthroscopy in the diagnosis of knee derangements.

The diagnostic efficiency of the Optical Catheter System (OCS), which uses a 1.7-mm arthroscope, was compared with that of conventional arthroscopy in 50 patients with various knee derangements in standard arthroscopic conditions. Correct diagnoses were obtained with the OCS in 98% of anterior cruciate ligament derangements--92%-98% of those involving the medial and lateral meniscus, respectively--and 96% of cartilage disorders. No false-positives were noted for anterior cruciate ligament and meniscus injuries. False-negatives were caused by abundant intraarticular bleeding (no tourniquet was applied) and peripheral meniscus tears and false-positives by synovial superposition resulting in a mistaken diagnosis of patellar chondromalacia. The OCS proved a good diagnostic tool. Its employment, especially in an outpatient setting, should be restricted to a small number of patients and entrusted to expert arthroscopists.

Adolescent↗

PubMed1993

MRI of intracranial meningiomas: correlations with histology and physical consistency.

Magnetic resonance imaging (MRI) appearances of 43 intracranial meningiomas were reviewed and correlated with their histology and consistency at surgery and on pathological examination. There was a statistically significant prevalence of hard tumours within the fibroblastic subtypes. No statistically significant correlation between signal intensity and histology or consistency was found. A meningioma hyperintense on T2-weighted images is, however, unlikely to be fibroblastic or hard.

Adult↗

PubMed1993

Dual X-ray absorptiometry for the evaluation of bone density from the proximal femur after total hip arthroplasty: analysis protocols and reproducibility.

Dual X-ray absorptiometry (DXA) instruments are now able to evaluate bone mineral density (BMD) of bone surrounding metal implants. The assessment of BMD around prosthetic components could provide additional information for the follow-up of total hip arthroplasty (THA). In this study, we evaluated the potential application of DXA in the field of THA. BMD was measured in the proximal femur of both THA and THA-free sides in 14 postmenopausal women 6-18 months after THA. The explored segment was divided into seven zones as proposed by Gruen et al. [18]. The precision error of BMD measurements ranged from 1.8 to 6.8% on the THA side and from 1.1 to 2% to the THA-free side. The reduction of BMD of the THA versus the THA-free side was significant in all seven zones (P < 0.01, t-test for paired data). These results showed significant differences in BMD around femoral components of THA with respect to contralateral healthy side, and demonstrate the sensitivity of DXA for detecting these changes.

Absorptiometry, Photon↗