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M Reggiani

Publications and source records attributed to M Reggiani.

At least 19 recordsLinked to original sources
PubMed2003

The performance of gamma- and EtO-sterilised UHMWPE acetabular cups tested under severe simulator conditions. Part 2: wear particle characteristics with isolation protocols.

Ultra-high molecular-weight polyethylene (UHMWPE) has been used in total joint replacement for the last three decades. Despite the recent advancements in prosthesis design, the wear of UHMWPE remains a serious clinical problem; the release of wear debris may induce osteolysis and implant loosening. Controlling the quality of the polyethylene is essential to improve its wear resistance and any potential adverse effect caused by processing, manufacturing or sterilisation should be avoided. To evaluate the influence of the sterilisation method (gamma-irradiation and ethylene oxide (EtO)-treatment) and third-body particles, gamma- and EtO-sterilised UHMWPE acetabular cups were tested against CoCrMo femoral heads in a hip joint simulator run for 2.5million cycles in bovine calf serum in the presence of third-body polymethylmethacrylate (PMMA) particles. A method not requiring ultra-centrifugation has been proposed for the isolation of polyethylene wear debris from the serum lubricant. SEM analysis allowed debris shape and morphology to be determined, and the wear mechanism operating in this study to be hypothesised. The morphological features of the wear debris were in agreement with clinical findings, enabling the hip simulator function to be validated. Micro-Raman spectroscopy coupled to PLS analysis showed that the mechanical friction during in vitro tests induced significant crystallinity changes in all the cups. The most significant changes were observed for the EtO-sterilised cups, which showed the highest weight loss.

Animals↗
PubMed2002

Atypical cutaneous mycobacteriosis diagnosed by polymerase chain reaction.

Atypical mycobacteria are important human pathogens. Although they often cause systemic disease, mycobacterial infection may present solely as cutaneous lesions. It is not easy to detect nontuberculous mycobacteria by the traditional histochemical Ziehl-Neelsen stain, or by culture on specific media. Polymerase chain reaction (PCR) may be used to identify nontuberculous mycobacteria in skin lesions. We report a 40-year-old man and a 36-year-old woman, both of whom were immunocompetent and kept fish, who had skin lesions on the backs of their right hands. Ziehl-Neelsen staining and culture on Lowenstein-Jensen media were negative. Mycobacterial DNA was detected by amplification of 16S ribosomal DNA. In both cases, PCR-enzyme-linked immunosorbent assay showed a positive signal when probes for Mycobacterium (universal probe) and M. chelonae were used, and in one patient M. fortuitum was also discovered. Antibiotic therapy with clarithromycin 500 mg twice daily was begun. After 6 months of treatment, the skin lesions were cured.

Adult↗
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↗
PubMed2001

Presence of telomerase activity in different musculoskeletal tumor histotypes and correlation with aggressiveness.

Telomerase is a ribonucleoprotein enzyme that maintains the protective structures at the ends of eukaryotic chromosomes, called telomeres. Telomerase activity was observed and correlated with aggressiveness in different neoplasms such as breast, prostate, blood and brain cancers, among others. To investigate whether telomerase activity is an index of aggressiveness in bone and soft tissue lesions of the extremities, 66 biopsy samples from our tissue bank were studied. These samples included 43 high-grade sarcomas, 9 aggressive benign tumors and 14 totally benign lesions. The samples were collected from patients homogeneously treated at the Rizzoli Orthopaedic Institute with a follow-up ranging from 4 to 11 years (median, 7 years). A non-radioactive polymerase chain reaction-based enzyme-linked immunosorbent assay was used for the study. All tumors investigated were positive for telomerase activity. Among benign lesions, only 2 aneurysmal bone cysts showed higher telomerase activity than the cut-off point, whereas all the other benign lesions had lower activity. Our results indicate that high levels of telomerase activity in bone and soft tissue lesions correlate with more aggressive clinical behavior in patients treated with surgery alone. An interesting inverse correlation between telomerase activity and occurrence of pulmonary metastasis was detected in osteosarcoma patients treated with chemotherapy. A parallel increase of telomerase activity and malignancy was observed in the adipose and cartilagineous tissue lesions. Our data suggest that telomerase activity could be considered a marker of tumor aggressiveness for bone and soft tissue lesions. The results obtained in osteosarcoma samples suggest that low levels of telomerase activity may be predictive of the prognosis and should influence the therapeutic protocol.

Bone Neoplasms↗
PubMed2000

Automatic atrial tachyarrhythmia detection from intracardiac electrograms.

BACKGROUND: Automatic atrial tachyarrhythmia recognition is crucial in order to allow a correct switching-mode function of dual-chamber pacemakers and to avoid inappropriate shocks of ventricular implantable cardioverter-defibrillators. In this paper we considered three algorithms suitable for implantable devices. The first was based on the atrial cycle length; the others analyze different morphologic characteristics of atrial signals. METHODS: Intracardiac bipolar electrogram recordings were obtained from the high right atrium during electrophysiological study. Twenty patients were considered, some of them presenting with different types of cardiac rhythm at different intervals of the study. Cardiac rhythms were divided into three groups: sinus rhythm consisting of 2,196 s obtained from 12 subjects, atrial fibrillation consisting of 771 s obtained from 7 subjects, and atrial flutter consisting of 1,793 s obtained from 7 subjects. The automatic detection was performed on each electrogram segment lasting 1 or 4 s. Atrial segments were separated into two subgroups: the first for the training of the algorithm and the second for testing and validation of results. We considered two types of statistical analysis: comparison between pairs of rhythm (paired classification), and classification among the three different groups (direct classification). RESULTS: The combination of the cycle length algorithm with a morphological method achieved the best performance for both statistical analyses. Paired classification resulted in the following: atrial fibrillation vs sinus rhythm was detected with no error; atrial flutter vs sinus rhythm with a total accuracy of 99.3% (sensitivity 99.4%, specificity 99.2%); atrial fibrillation vs atrial flutter with a total accuracy of 99.1% (sensitivity 98.5%, specificity 99.4%). The total accuracy achieved for the direct classification was 98.6% (average sensitivity 98.5%, specificity 98.8%). CONCLUSIONS: Our results support the association of algorithms for future enhancement of atrial tachyarrhythmia detection in dual-chamber devices, thanks to the limited computational effort.

Algorithms↗
PubMed1996

Occupational dermatitis in shoemakers.

In an epidemiological study of occupational dermatitis in 5 different shoe factories, 246 workers were interviewed, examined and patch tested using standard and occupational patch test series. The prevalence of occupational contact dermatitis was 14.6% (36/246): 8.1% (20/246) irritant contact dermatitis (OICD) and 6.5% (16/246) allergic contact dermatitis (OACD). Among the latter, the most common occupational allergens were p-tert-butylphenol-formaldehyde resin and mercaptobenzothiazole. 6% (15/246) presented with hyperkeratosis of the fingertips, while 3.2% (8/246) reported pruritus sine materia (PSM) present only during working hours. 2 workers presented with vitiligo-like leukodermic patches on the backs of their hands and on their forearms. Some jobs were more frequently associated with skin complaints. In the assembly department, OACD was most frequent (11.4%), attributed to contact with adhesives and, to a lesser degree, with rubber and leather. OICD caused by contact with the solvents contained in adhesives and varnishes was most frequent in the assembly and trimming departments (17.1% and 15.6%, respectively). PSM, probably caused by the dust present in the working environment was reported by 33.3% of the workers in the sole-cutting and scraping departments. Hyperkeratosis of the fingertips, as a reaction to the continuous trauma of leather on the skin, was observed most frequently (41.6%) in the sole-cutting department.

Adhesives↗
PubMed1990

Hairy leucoplakia in liver transplant patient.

Oral hairy leucoplakia has been described only in patients infected with the human immunodeficiency virus (HIV) and is a significant predictor for the subsequent development of AIDS. The occurrence of hairy leucoplakia in a liver transplant patient suggests that the lesion is not restricted to HIV seropositive individuals, but can be found in other categories of immunosuppressed patients.

Female↗
PubMed1990

[Tungiasis. A clinical case].

Tungiasis is a cutaneous infestation by the female sand flea, Tunga penetrans. Because of the increase in international travel, the disease is reported in Europe, in spite of it being formerly restricted to the equatorial zones. This report describes a case of tungiasis and discusses clinical features, diagnosis and treatment.

Adult↗