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Biomedical subjects

P Liberti

Publications and source records attributed to P Liberti.

At least 19 recordsLinked to original sources
PubMed2000

Correlation between chronic prostatitis syndrome and pelvic venous disease: a survey of 2,554 urologic outpatients.

OBJECTIVES: In this study we evaluated the association between chronic prostatitis syndrome (CPS), varicocele and hemorrhoids as manifestations of a pelvic venous disease. METHODS: Our retrospective study was based upon 2,554 patients treated in two general urology clinics over the past 10 years. We have assessed the incidence of CPS among urological patients. RESULTS: We found 483 patients with CPS, representing 18.9% of the total number of visits at the outpatient clinic. In this group the percentage of varicocele and hemorrhoids was 14.69 and 8.48%, whereas in a control group these figures were 5.02 and 5.84%, respectively (p<0.001 and 0.1054). Such a difference is statistically significant and suggests a higher prevalence of varicocele in the CPS group, but this may be due to a methodological error of the retrospective study. CONCLUSION: Only a prospective study, which is of importance due to the frequency of the disease, can give a precise answer to this question.

Case-Control Studies↗
PubMed1999

Stage-specific expression of a Schistosoma mansoni polypeptide similar to the vertebrate regulatory protein stathmin.

The ubiquitous vertebrate protein stathmin is expressed and phosphorylated in response to a variety of external and internal signals. Stathmin, in turn, controls cell growth and differentiation through its capacity to regulate microtubule assembly dynamics. This is the first report on the molecular cloning and characterization of a stathmin-like protein (SmSLP) in an invertebrate, the human blood fluke Schistosoma mansoni. SmSLP is first synthesized at high levels in the intermediate molluscan host and completely disappears 48 h after penetration into the mammalian host. The protein is preferentially iodinated in intact immature parasites using the Bolton-Hunter reagent, can be quantitatively extracted in high salt buffers, and remains soluble after boiling. Native SmSLP was partially sequenced, and its complete structure was derived from the cloning and sequencing of its cDNA. The sequence is up to 26% identical to vertebrate stathmin sequences and contains two potential phosphorylation sites. Native SmSLP is indeed phosphorylated because phosphatase digestion shifts its mobility in electrofocusing gels. SmSLP associates with tubulin, as suggested by immune co-precipitation results. In vitro experiments demonstrated that SmSLP inhibits tubulin assembly and causes the depolymerization of preassembled microtubules, thus probably fulfilling regulatory roles in critical steps of schistosome development.

Amino Acid Sequence↗
PubMed1994

Immunomagnetic colloids for the enrichment of tumor cells from peripheral blood and bone marrow: a model system.

The characterization of tumor cells in bone marrow harvested for autologous bone marrow rescue remains a problem due to the limited sensitivities of the techniques available for their analysis. This complicates the use of purging techniques as their usefulness is debated, specifically because it is not known if they can remove all residual tumor cells from either peripheral blood stem cell harvests or bone marrow. Apart from developing more sensitive techniques for tumor detection, one way of increasing our efficiency at identifying rare malignant cells in normal hematopoietic cells is to develop approaches to enrich the population of interest prior to analysis. Here, we describe a laboratory-based system for tumour enrichment employing panels of monoclonal antibodies (MAbs) and an immunomagnetic colloid. In model systems, tumor cells could be enriched approximately 100-fold with high yield and purity. The adaptations of this technology to permit further cell enrichment and the choice of either an immunological technique or a molecular approach to tumor identification are discussed in detail.

Bone Marrow↗
PubMed1992

Magnetic resonance imaging of abscesses using lipid-coated iron oxide particles.

RATIONALE AND OBJECTIVES: The authors investigated whether iron oxide particles can be used as a magnetic resonance imaging (MRI) contrast agent to image abscesses in a two-stage experimental design. METHODS: Human buffy coat was incubated with iron oxide particles of different sizes and coatings. Smears of the incubation mixture were made on a glass slide and stained for iron. The percentage of iron oxide uptake was determined by counting 100 neutrophils and monocytes and scoring the number of cells that contain iron. Subcutaneous abscesses were created in the flanks of 18 Sprague-Dawley rats by injecting them with 0.1 mL of turpentine. Iron oxide was given intravenously, and the animals were imaged by MRI (1.5 T) 12 to 24 hours later. Different iron oxide coatings and doses were compared. RESULTS: The four different types of coating (constant fragment [Fc] of IgG, bovine serum albumin [BSA], lipid [Ferrosome], and dextran) had an uptake of 72% +/- 5.3%, 61% +/- 6.2%, 30.5% +/- 6.8%, and 5% +/- 2.5%, respectively. Comparison of two particle sizes (mean, 90 versus 35 nm) showed the large particles to have higher uptake (61% +/- 6.2%) compared with the small particles (6% +/- 1.8%) (P less than .001). Post-contrast imaging of the rats showed a hypointense ring around the abscess only in the animals injected with the lipid-coated agent. The effect was discernible within 12 hours after contrast injection and at a dose of 25 mumols iron/kg. Histologic sections showed phagocytic cells with iron granules in the periphery of the abscess. No hypointense ring on MRI or iron granules on histologic sections was seen around the abscess of the control animals or those injected with BSA-iron oxide or Fc-iron oxide. CONCLUSIONS: Lipid-coated iron oxide particles can be used to image abscesses by virtue of their phagocytosis into surrounding inflammatory cells. Positive uptake of these particles by human phagocytes in vitro suggests that similar results may be applicable in humans.

Abscess↗
PubMed1986

A surface-labeled 18 kilodalton antigen in Schistosoma mansoni.

A mild surface-labeling procedure was applied to various developmental stages of Schistosoma mansoni. An 18 kDa protein was preferentially labeled in freshly transformed schistosomula. The labeled protein was equally present on skin-penetrated and mechanically prepared schistosomula and it disappeared upon digestion of intact parasites with proteolytic enzymes. The 18 kDa protein could be specifically precipitated with an antiserum raised against 3-h schistosomula. Six-day lung forms also presented a single major labeled protein component, but the apparent molecular weight of this protein in acrylamide gels was higher than 18 000. Fourteen-day-old and adult schistosomes showed only weak labeling distributed in several bands. The radioactivity pattern of adult worms (but not of schistosomula) could also be obtained by incubating fresh parasites in a medium which had previously been used to label schistosomes and to which a 100 000-fold excess of 127I over 125I had been added. Post-labeling incubation of parasites was found to be essential for the detection of stable surface proteins.

Animals↗