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Biomedical subjects

M Zanetti

Publications and source records attributed to M Zanetti.

At least 253 records · Page 14Linked to original sources

MRI of patellar articular cartilage: evaluation of an optimized gradient echo sequence (3D-DESS).

Our purpose was to evaluate the diagnostic efficacy of a gradient-echo sequence optimized for cartilage imaging in patellar cartilage abnormalities and to compare it to a standard turbo-spin-echo sequence. Fifty-eight consecutive patients who underwent, within 3 months both MRI and arthroscopy or surgery, were included in the investigation. Two radiologists specializing in musculoskeletal imaging independently assessed axial three-dimensional double-echo steady state (3D-DESS) gradient-echo images and sagittal proton- and T2-weighted turbo-spin-echo images with regard to retropatellar cartilage abnormalities. Possible findings were: 0: normal, 1: cartilage softening, and 2: lesion of the articular surface. Inter- and intraobserver variability was assessed. For cartilage softening, the axial 3D-DESS sequence had a sensitivity of 73%, a specificity of 75%, and an accuracy of 70%. The corresponding results for the sagittal turbo-spin-echo sequence were 53%, 65%, and 62%. For surface lesions, the results for the 3D-DESS sequence were 43%, 92%, and 83% and for the turbo-spin-echo sequence were 60%, 92%, and 86%. Intra- and interobserver agreement was moderate (k = 0.59 and 0.45 [DESS], 0.6 and 0.46 [turbo -spin-echo]). We conclude that the 3D-DESS sequence is moderately accurate in detecting patellar cartilage abnormalities. Compared with the sagittal turbo-spin-echo sequence, the axial 3D-DESS sequence is superior in diagnosing cartilage softening but not surface lesions.

Adolescent↗

Durable immunity and immunologic memory to a parasite antigen induced by somatic transgene immunization.

Somatic transgene immunization (STI) is an alternative approach to immunization mediated by inoculation of plasmid DNA. In the experiments presented here we show that inoculation of plasmid DNA carrying an immunoglobulin heavy chain gene under the control of tissue-specific regulatory elements, leads to immunity and persistent immunologic memory against a peptide epitope encoded in the third complementarity-determining region. The epitope consists in three repeats of the tetrapeptide Asn-Ala-Asn-Pro (NANP) and is the immunodominant B cell epitope expressed at the surface of Plasmodium falciparum malaria parasite. When inoculated directly in the spleen the plasmid DNA initiated a specific anti-NANP response which lasted for 2 years. During the initial phase of priming the anti-NANP response was higher than that induced by immunization with recombinant protein in immunologic adjuvants. The establishment of immunologic memory was probed by single booster injection at various times after priming. We found that STI induces persistent immunologic memory up to 2 years. The immunologic characteristics of this new model are examined with respect to the requirement for the induction of B cell memory.

Animals↗

Massive intraperitoneal and extraperitoneal accumulation of irrigation fluid as a complication during knee arthroscopy.

A case of uncommon fluid extravasation during knee arthroscopy leading to a swelling of the groin, scrotum, and penis, with massive intraperitoneal and retroperitoneal fluid accumulation is reported. A defective pump pressure sensor relay was found to be the cause of uncontrolled fluid delivery with excessive intra-articular pressure increase. The literature reports several cases of extravasation of irrigation fluid into the calf without any sequelae. Our patient experienced proximal expansion of the fluid that expanded along the vastus intermedius and shunted into the retroperitoneal and intraperitoneal space. There was no clinical evidence of compartment syndrome despite the excessive amount of extravasation in the thigh. Diuretics were administrated, and the fluid was excreted within 36 hours. The patient suffered of no further sequelae.

Adult↗

Fatty degeneration of the muscles of the rotator cuff: assessment by computed tomography versus magnetic resonance imaging.

Forty-one patients scheduled for shoulder surgery underwent computed tomography (CT) and magnetic resonance imaging (MRI) examination of their affected shoulder to verify whether fatty degeneration of the rotator cuff muscles could reproducibly be assessed by CT or by MRI and whether the grading with the 2 methods was comparable. In addition, rotator cuff muscle cross-sectional areas were measured on parasagittal MRI scans to establish a possible correlation between rotator cuff muscle atrophy and fatty degeneration. Interobserver reproducibility for grading fatty degeneration was good to excellent for CT and for MRI. The correlation between MRI and CT was fair to moderate and remained unsatisfactory, even if the classification system was simplified with only a 3- rather than a 5-grade scale as originally proposed. The degree of fatty degeneration was significantly related to the amount of atrophy of the respective muscles.

Adult↗

Expression and function of recombinant endothelial nitric oxide synthase in human endothelial cells.

Endothelial dysfunction is frequently involved in the pathogenesis of vascular disease. While nitric oxide (NO) inhibits smooth muscle cell proliferation, its effect on endothelial cell proliferation is unclear. The aim of this study was to determine if adenoviral-mediated gene transfer of endothelial NO synthase (eNOS) to human umbilical vein endothelial cells (HUVECs) would result in increased generation of NO and affect endothelial cell proliferation. HUVECs were transduced with adenoviral vectors encoding eNOS (AdeNOS) or beta-galactosidase (Ad beta gal) or exposed to diluent (control). AdeNOS-transduced cells showed increased eNOS expression as detected by Western blot analysis, and increased concentrations of cGMP (control 0.7 +/- 0.1; Ad beta gal 0.9 +/- 0.2; AdeNOS 3.1 +/- 0.5 pmol/mg protein; p < 0.001) and nitrite (control 11.8 +/- 1.2; Ad beta gal 13.3 +/- 1.7; AdeNOS 21.1 +/- 2.2 nmol/mg protein/hour; p < 0.01). DNA synthesis as assessed by [(3)H]thymidine incorporation and cell counts were significantly reduced (by approximately 30%) in AdeNOS-transduced HUVECs. Expression of mitogen-activated protein kinase was also decreased in AdeNOS-transduced cells. This study shows that adenoviral-mediated gene transfer of eNOS to HUVECs inhibits endothelial cell proliferation.

Adenoviruses, Human↗

The coexistence of rheumatoid arthritis and systemic lupus erythematosus: a case report and review of the literature.

We describe a patient with longstanding classical erosive rheumatoid arthritis (RA), who after many years developed the clinical and serological manifestations of systemic lupus erythematosus (SLE) including diffuse proliferative lupus nephritis. She fulfilled the ARA preliminary criteria for the classification of SLE as well as the ARA criteria for classical RA. In addition she had antibodies to native DNA, hypocomplementemia, and deposits of immunoglobulins at the dermal-epidermal junction of the non-lesional skin. The rarity of the concurrence of these 2 diseases in the same patient and the discriminating findings with tissue typing analysis suggest that this coexistence may be coincidental.

Adult↗