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R Mazzucchelli

Publications and source records attributed to R Mazzucchelli.

45 records · Page 3Linked to original sources
PubMedDate not supplied

Nerve regeneration through a combined autologous conduit (vein plus acellular muscle grafts).

The authors describe nerve regeneration obtained by using a combined autologous conduit, consisting of a vein plus acellular muscle grafts. The right sciatic nerve of seven Sprague Dawley rats was transected for a length of 2 cm and the gap was filled with 2 cm long femoral vein conduit in which two autologous acellular muscle grafts had been previously inserted. Clinical and electrophysiologic tests were carried out twelve weeks after the surgical procedure. The nerve was then removed and a morphological study, including histologic examination, immunohistochemistry and quantitative analysis, was performed. The left sciatic nerve was also removed and used as a control. Regeneration was observed in the middle and distal parts of the conduit in 5 rats. Nerve conduction velocity ranged between 0 and 14.9 ms(-1). In the distal part the nerves were enclosed by a perineurium thicker than their normal counterpart and in which groups of small axons were surrounded by thin myelin sheaths. Quantitative analysis showed that the operated nerve presented a wide variation of the area of the fascicle and the density of the fibres per area, while the diameter of the axons and myelinated fibres showed only small variation, independent of the size of the fascicle. In conclusion, by using this technique, the authors succeeded in obtaining regeneration of a well formed nerve fascicle.

Animals↗
PubMedDate not supplied

Prevalence of HIV-1 resistant strains in recent seroconverters.

Twenty-nine HIV-1 recently infected subjects were retrospectively studied to investigate both the prevalence of nucleoside reverse transcriptase inhibitors (NRTI)-related mutations at primary infection and the proportion of naturally occurring mutations in protease inhibitor (PI)-naive patients. Neither HIV-1 plasma viremia nor CD4 absolute count at baseline could distinguish patients with NRTI pre-existing mutations from those with wild-type virus. An increasing proportion of ZDV-related mutations was observed over time with an overall frequency of 20.7% in the study period. Only 1 out of 6 patients (16.7%) with ZDV-related mutations showed a phenotypically ZDV resistant isolate. A striking proportion of polymorphic changes was present in the protease region of pol gene in newly infected individuals. As many as 80% of seroconverters presented at least one naturally occurring substitution. Some PI-associated substitutions, thought to be compensatory in protease enzymatic function, could confer intermediate to high PI-resistance. Their role following PI administration remains to be elucidated. Our data suggest that the choice of drugs should be oriented by both genotypic and phenotypic evaluations to tailor individual regimens in seroconverters.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Urothelial papillary lesions. Development of a Bayesian Belief Network for diagnosis and grading.

The diagnosis and grading of urothelial papillary lesions are affected by uncertainties which arise from the fact that the knowledge of histopathology is expressed in descriptive linguistic terms, words and concepts. A Bayesian Belief Network (BBN) was used to reduce the problem of uncertainty in diagnostic clue assessment, while still considering the dependencies between elements in the reasoning sequence. A shallow network was designed and developed with an open-tree topology, consisting of a root node containing four diagnostic alternatives (papilloma, papillary carcinoma grade 1, papillary carcinoma grade 2 and papillary carcinoma grade 3) and eight first-level descendant nodes for the diagnostic features. Six of these nodes were based on cell features and two on the architecture. The results obtained with prototypes of relative likelihood ratios showed that belief in the diagnostic alternatives is very high and that the network can identify papilloma and papillary carcinoma, including their grade, with certainty. In conclusion, a BBN applied to the diagnosis and grading of urothelial papillary lesions is a descriptive classifier which is readily implemented and allows the use of linguistic, fuzzy variables and the accumulation of evidence presented by diagnostic clues.

Bayes Theorem↗
PubMedDate not supplied

Role of CCR5, CCR2 and SDF-1 gene polymorphisms in a population of HIV-1 infected individuals.

The finding that in addition to CD4 molecule HIV-1 uses, CCR5 or CXCR4 receptors to enter target cells prompted the research to identify polymorphisms in coreceptor genes affecting disease progression. In this study we analyzed the prevalence of CCR5-delta32, CCR2-641 and SDF1-3'A alleles in a highly selected group of 42 Long-Term Nonprogressors (LTNPs) compared to 112 subjects with a typical course of HIV-1 infection (TPs) and 117 healthy controls (HCs). In addition, we correlated CCR5, CCR2 and SDF-1 genotypes with molecular indexes of HIV-1 replication, cell-free RNA and both unspliced (US) and multiply spliced (MS) intracellular transcripts, to investigate the role of the mutant alleles in determining a long-term nonprogressive course of HIV-1 disease. Our results indicate a significantly higher prevalence of CCR5-delta32 allele in LTNPs compared to TPs (p=0.0434), while the proportions of CCR2-64I and SDF1-3'A alleles were comparable between the two groups. However, SDF-1 wild type LTNP subjects showed significantly lower levels of HIV-1 genomic RNA, US and MS transcripts than SDF1-3'A heterozygous ones (p=0.0021, 0.016, 0.0031, respectively), whereas both CCR5 and CCR2 wild type individuals had similar rates of viral replication compared to CCR5-delta32 and CCR2-64I heterozygous ones. CCR5, CCR2 and SDF-1 combined genotypes were also studied and this analysis did not identify a specific protective cluster of alleles in LTNPs. Taken together, our results indicate that genetic background involving CCR5, CCR2 and SDF-1 alleles may play a limited role in the natural history of HIV-1 infection.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Surgical pathology examination of radical prostatectomy specimens. Updated protocol based on the Italian TAP study.

Between January 1996 and June 2000, 192 men with prostate cancer underwent radical retropubic prostatectomy (RP) and bilateral pelvic node dissection in 26 centers participating in the Italian randomized prospective TAP study. The reviewing pathologist evaluated 145 RP specimens. Seventy-five cases had not been treated with total androgen ablation before RP was performed, whereas 70 had been treated for three months. Whole-mount sectioning of the complete radical prostatectomy specimens was adopted in each center for accurately evaluating the pathological stage of prostate cancer and resection limit status. The results of this study suggest that total androgen ablation before RP is beneficial in men with clinical stage T2 because of the significant pathological down-staging and decrease in the number of positive margins in the RP specimens. On the basis of the experience acquired through the Italian TAP study and recent publications on prognostic factors in prostate cancer, the original practice protocol for examination of RP specimens removed from patients with carcinoma of the prostate glands was updated.

Androgen Antagonists↗
PubMedDate not supplied

Double disease in rheumatology: coexistence of rheumatoid arthritis and psoriatic arthritis.

Since rheumatoid arthritis (RA) and psoriatic arthritis (PA) are common diseases, there should be a group of patients in which the two entities coexist, with an estimated prevalence ranging from 0.03/10,000 to 0.15/10,000. The two entities may share clinical, analytic and radiologic features that further complicate the diagnosis. We report here a patient in whom RA and PA coexisted. The features that differentiate peripheral arthritis in RA and PA are discussed.

Arthritis, Psoriatic↗
PubMedDate not supplied

Catastrophic antiphospholipid syndrome (CAS): a rare manifestation of the antiphospholipid antibody syndrome.

During the last decade, antiphospholipid antibodies and their clinical manifestations have given rise to increasing interest and have been associated with a wide spectrum of clinic expression, including arterial and venous thrombosis, thrombocytopenia, recurrent fetal wastage, Coombs positive haemolysis, livedo reticularis and neurological abnormalities, commonly present as isolated recurrent events, and rarely characterized by fatal outcome. Recently, an acutely disseminated vasculopathy, the so-called "catastrophic antiphospholipid syndrome" (CAS) characterized by non-inflammatory vascular occlusion and frequency of fatal outcome, has been described. We present yet another case report of this new and poorly understood entity and review its antecedents, clinical manifestations, serological profile, treatment and outcome.

Antiphospholipid Syndrome↗