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R Preziosi

Publications and source records attributed to R Preziosi.

At least 19 recordsLinked to original sources
PubMed2006

Multivariate survival analysis of histological parameters and clinical presentation in canine cutaneous mast cell tumours.

The Patnaik histological grade is a good method for the prediction of long-term mast cell tumour behaviour but it is influenced by subjective inter-observer variations and intratumoral heterogeneity. The present study evaluated each of the histopathological parameters used to formulate Patnaik's grade in terms of prognosis and tested whether they have a different prognostic sensitivity, thereby disclosing which could be considered more useful in the prediction of tumour recurrence and patient survival. Clinical presentation (single or multiple tumours) was also considered as possible prognostic factor. The results demonstrated that individual histological criteria together with multiple presentation may be of value in predicting the outcome of mast cell tumours. Among these, invasiveness (beta1.85; standard error 1.15) and the number of mitotic figures (beta3.01; standard error 1.18) showed high prognostic significance (Cox proportional hazard regression for censored data; chi-squared = 15.52, degree of freedom = 6, p = 0.016) and could serve as reliable prognostic indicators avoiding more subjective parameters such as cellular differentiation, nuclear morphology and tumoural pattern.

Animals↗
PubMed2006

Acromegaly due to a somatroph adenoma in a dog.

A 10-year-old uncastrated male Dalmatian dog was referred for gait abnormalities consisting of chronic progressive stiffness and rigidity. Other symptoms were polyphagia associated with weight gain, polyuria and polydipsia, excessive panting, and an inspiratory stridor. The owner had noticed progressive thickening of the skin and enlargement of the tongue over the last 3 years. Physical examination revealed thickening of the skin, redundant skin folds, and enlargement of the tongue. The only remarkable abnormalities found on routine laboratory examination were mild anaemia and an increased serum fructosamine concentration. Circulating concentrations of total thyroxine, free thyroxine, and cTSH, and the results of an ACTH stimulation test were all within reference ranges. The basal serum growth hormone (GH) concentration was markedly elevated (23microg/l) and did not decrease during a glucose tolerance test or after somatostatin administration. The serum insulin-like growth factor-1 concentration was also markedly elevated (1254microg/l). Basal serum insulin concentration was high (95mU/l) and insulin concentrations increased considerably after glucose loading, consistent with insulin resistance. Abdominal ultrasonography showed no abnormalities. Survey radiographs of the vertebral column showed severe spondylosis deformans extending from the cervical to the lumbosacral spine. CT scanning of the skull showed an enlarged pituitary gland with normal enhancement pattern. On post-mortem examination, the entire vertebral column appeared as a single and inflexible structure due to the presence of multiple fused osteophytes. The pituitary gland contained an acidophilic adenoma that immunostained positively for GH (and negatively for ACTH and alpha-MSH). In conclusion, this Dalmatian dog with acromegaly and insulin resistance represents the first case of GH hypersecretion proven to be due to a somatotroph adenoma.

Acromegaly↗
PubMed2006

Spinal deformity in a sandtiger shark, Carcharias taurus Rafinesque: a clinical-pathological study.

The present study investigated spinal deformity in a captive sandtiger shark and describes the clinical and histopathological features of the lesion. Clinically, the shark presented a marked spinal curvature in the region between the pectoral girdle and cranial dorsal fin. Radiographic studies revealed scoliosis and kyphosis of the vertebral column with a modification of the basic structure of five vertebrae. Post-mortem examination confirmed the results of radiographic studies and histological examination showed remodelling and cartilaginous proliferation of the vertebral bodies together with necrosis, haemorrhage and signs of a local chronic inflammatory response extending to the surrounding muscle. Different aetiologies are proposed and discussed but nutritional imbalance (dietary vitamin deficiency) and/or traumatic injury are considered the most likely contributing factors.

Animals↗
PubMed2005

E-cadherin and beta-catenin reduction influence invasion but not proliferation and survival in canine malignant mammary tumors.

E-Cadherin and beta-catenin are known for their role in tumor invasion, but both proteins also exert an influence on tumor proliferation. This study, performed on canine mammary tumors, aimed to analyze the influence of E-cadherin (E-cad) and beta-catenin (beta-cat), immunohistochemically assessed singly and in combination (E-cad/beta-cat), on survival and their relationship with several proliferation indices (AgNOR index, MIB1 index, mitotic index). Immunohistochemistry was carried out on 60 formalin-fixed, paraffin wax-embedded specimens of canine mammary malignancies. The labeling was defined as preserved when prevalent on cell membranes of more than 75% of cells and reduced in other forms of expression (i.e., membranous less than 75%, cytoplasmic, and negative). E-cad, beta-cat, and E-cad/beta-cat were preserved respectively in 22, 12, and 11 out of 60 cases. Immunohistochemical expression of the two proteins in the same tumors was significantly correlated (P = 0.0001; R = 0.57). Survival analysis revealed no difference in outcome comparing the preserved versus reduced cases (E-cad, P = 0.31; beta-cat, P = 0.29; E-cad/beta-cat P = 0.36). Grouping cases for histologic invasiveness, the expression of E-cad or beta-cat and E-cad/beta-cat showed a progressive reduction that paralleled an increase in invasiveness from noninfiltrating to stage-II tumors (E-cad, P < 0.001; beta-cat, P < 0.05; E-cad/beta-cat, P < 0.05). No significant difference was obtained comparing mitotic index, MIB 1 index, and AgNOR index by analysis of variance between the cases grouped for preserved or reduced E-cad, beta-cat, and E-cad/beta-cat variables. In conclusion, reduced expression of E-cad, beta-cat, or E-cad/beta-cat was significantly associated with the progression from noninfiltrating to highly infiltrating tumors but not with proliferation or survival.

Analysis of Variance↗
PubMed2003

Hypertrophy of intestinal smooth muscle in cats.

Pathological findings of four cats with severe and diffuse smooth muscle hypertrophy of the small intestine (MHSI) are reported and compared to those of five cats with segmental MHSI secondary to neoplastic obstruction and four controls. Histology demonstrated a constant association between idiopathic MHSI and submucosal fibrosis and chronic lymphoplasmacytic enteritis. Morphometry (gut diameter, thickness and area of muscular layers, number and density of smooth muscle nuclei) and MIB-1-immunolabelling showed that the thickness increase was mostly due to hypertrophy, but hyperplasia was also evident. Microbiology from ileal content samples was performed in two cats with primary MHSI, and Campylobacter spp. were isolated, which were also demonstrated by immunohistochemistry and ultrastructure. The association of chronic enteritis with idiopathic MHSI suggests that factors released in intestinal inflammation may also act as hypertrophy stimuli for smooth muscle cells.

Animals↗
PubMed2003

E-cadherin expression in canine mammary carcinomas with regional lymph node metastases.

E-cadherin (E-cad) is a cell adhesion molecule known for its tumour invasion-suppressor function. This study investigated the immunohistochemical expression of E-cadherin in 19 cases of malignant mammary tumours of the dog and the relationship between E-cadherin expression in primary tumours and in regional lymph node metastases. E-cadherin expression is not always parallel in the primary tumour and in the lymph node metastasis. One year follow-up was available in 12 of 19 cases. Three different patterns of expression were revealed in the lymph node metastases compared with the primary tumour: downregulation when the protein expression was weaker in the metastasis than in the primary tumour; upregulation when E-cadherin was stronger in the lymph node than in the primary tumour, and a similarly intense expression when it was equal in the metastasis and in the tumour. The lymph node pattern revealed a prevalent upregulation or downregulation with respect to the primary tumour, whereas a similar expression of E-cadherin was encountered in less than 50% of cases.

Animals↗
PubMed2002

Cell proliferation patterns in canine infundibular keratinizing acanthoma and well differentiated squamous cell carcinoma of the skin.

The aim of the present study was to investigate if the evaluation of cell proliferation of the well differentiated squamous cell carcinoma (WDSCC) and infundibular keratinizing acanthoma (IKA) could be useful in the differential diagnosis between these two tumours. Eighteen IKAs and ten WDSCCs were selected for this study. Two different methods were used to assess the activity of cell proliferation: MIB1 immunohistochemical detection and AgNOR proteins silver staining. The quantification of proliferative parameters was performed by means of an image analyzer and expressed as MIB1 index and AgNOR area (MNORA). Both MIBI immunohistochemical and AgNOR histochemical patterns were different in WDSCC and IKA; moreover analysis of variance showed a significant difference for both parameters employed (MIB1 index, MNORA) between WDSCC and IKA (P<0.003 for MIB1 index; P<0.0001 for AgNOR area). The results show that canine WDSCC and IKA have a different proliferative behaviour and the assessment of cell proliferation can be considered as a useful adjunctive tool to the histopathological investigation in the differential diagnosis of these tumours.

Animals↗
PubMed2001

Rapid methods to extract DNA and RNA from Cryptococcus neoformans.

Extraction of nucleic acids from the pathogenic yeast Cryptococcus neoformans is normally hampered by a thick and resistant capsule, accounting for at least 70% of the whole cellular volume. This paper presents procedures based on mechanical cell breakage to extract DNA and RNA from C. neoformans and other capsulated species. The proposed system for DNA extraction involves capsule relaxation by means of a short urea treatment and bead beating. These two steps allow a consistent extraction even from strains resistant to other procedures. Yield and quality of DNA obtained with the proposed method were higher than those obtained with two earlier described methods. This protocol can be extended to every yeast species and particularly to those difficult to handle for the presence of a capsule. RNA purification is accomplished using an original lysing matrix and the FastPrep System (Bio101) after a preliminary bead beating treatment. Yields range around 1 mg RNA from 15 ml overnight culture (10(9) cells), RNA appears undegraded, making it suitable for molecular manipulations.

Centrifugation↗
PubMed2000

Cell proliferation and apoptosis in the pathogenesis of oesophagogastric lesions in pigs.

Recent studies have stressed the importance of epithelial hyperproliferation in the pathogenesis of early lesions (parakeratotic hyperkeratosis) of the porcine gastric pars oesophagea (PO). In this study, immunohistochemical staining with Ki67 (clone MIB1) and AgNOR proteins silver staining were used to evaluate, by means of image analysis, cell proliferation in normal and parakeratotic (parakeratotic hyperkeratosis) epithelia of the PO. Apoptotic activity was also assessed with the TUNEL assay and compared with cell proliferative parameters. Early lesions of the PO were characterised by a significant increase in epithelial proliferative activity while there was no difference in the apoptotic activity between normal and parakeratotic epithelia. Our data confirm the hyperproliferative nature of epithelial changes preceding degeneration and erosion/ulcer of the PO and suggest that an underlying feature of gastric ulcers in pigs is an imbalance between cell proliferation and programmed cell death.

Animals↗
PubMed1999

Granulocyte-macrophage colony-stimulating factor and fluconazole enhance anti-cryptococcal activity of monocytes from AIDS patients.

OBJECTIVE: To investigate the effect of human recombinant granulocyte-macrophage colony-stimulating factor (hrGM-CSF) and fluconazole on anti-cryptococcal activity of monocytes from AIDS patients and normal subjects. DESIGN: The effect of GM-CSF and fluconazole on fungistatic and fungicidal activity of monocytes was studied in an in vitro system. METHODS: Monocytes were treated in vitro with hrGM-CSF and fluconazole or either agent alone for 24 or 48 h, and fungistatic and fungicidal activity was evaluated in a colony-forming unit inhibition assay. CD11b/CD18 expression in monocytes was measured by flow cytometry analysis. Superoxide anion generation by peripheral blood monocytes was measured in the presence of pre-opsonized zymosan. RESULTS: Defective antifungal capacity of monocytes from AIDS patients was observed. GM-CSF treatment of monocytes from AIDS patients increased fungistatic activity, and the combination of hrGM-CSF and fluconazole resulted in fungicidal activity. The mechanisms involved in the GM-CSF-mediated effect appeared to be mediated by (i) enhancement of phagocytic activity, (ii) increase of superoxide anion generation, and (iii) upregulation of CD11b/CD18 expression on the monocyte surface. CONCLUSIONS: Our data highlight the effect of GM-CSF on anti-cryptococcal activity of human monocytes and show a synergistic effect of GM-CSF with fluconazole, suggesting a new therapeutic strategy in the treatment of cryptococcosis.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Evaluating mitotic activity in canine and feline solid tumors: standardizing the parameter.

Three different methods for evaluating mitotic activity (mitotic count, mitoses/area, mitotic index) were applied to different types of canine and feline solid tumors to determine the method that is most objective and correlates best with other parameters of cell proliferation. Mitotic activity was evaluated on toluidine blue stained histological sections. Slides stained with histochemical (AgNOR proteins) and immunohistochemical (MIB1, PCNA) markers of cell proliferation were available for each case. Quantitation of mitotic activity and cell proliferation parameters was performed with an image analyzer. Mitotic activity assessment was compared with cell proliferation indices and its ability to discriminate tumors grouped on histologically based criteria including the histological type, malignant or benign characteristics, and grade. A significant correlation by linear regression analysis with other parameters assessing cell proliferation revealed that mitotic index correlated 1000% and mitoses/area and mitotic count correlated 40% of the time. In discriminating the proliferative activity of tumors grouped by histological criteria, mitotic index and mitotic count revealed 1000% concordance with the other parameters of cell proliferation, while mitoses/areas showed 80% concordance.

Animals↗
PubMed1997

Assessment of fibromyxoma cell proliferation in a tench (Tinca tinca L.) by the silver staining nucleolar organizer region (AgNOR) technique.

A previously described fibromyxoma in a tench was examined for AgNOR proteins and mitotic index to evaluate the cell proliferation of the different tissue areas forming the tumorous mass. The different areas were: myxoid (myxoid cells in a mucous ground substance with few reticular fibres), collagenous (fibroblast-like cells and collagenous fibres) and mixed areas (intermediate cytological and histological features). A significant (P < 0.01) difference in cell proliferative activity between the three different areas was found by the AgNOR technique and confirmed by the mitotic index. The myxoid areas appeared to be the true proliferative compartment of the tumour, whereas the collagenous areas probably played a structural role, related to low cellular proliferative activity. The AgNOR technique appeared to be a convenient method for the rapid evaluation of cell proliferation in fish tissues.

Animals↗
PubMed1997

Immunogenicity of influenza vaccine (1993-94 winter season) in HIV-seropositive and -seronegative ex-intravenous drug users.

The humoral response (haemagglutination inhibiting antibodies) to trivalent split influenza vaccine for the 1993-94 winter season (A/Beijing/32/92 (H3N2), A/Singapore/6/86 (H1N1) and B/Panama/45/90) was evaluated in a group of young HIV-seropositive ex-intravenous heroin users and compared with responses measured in HIV-seronegative individuals with a similar history. HIV-negative volunteers showed an overall positive response suggesting that previous heroin use did not influence their humoral response to influenza vaccine. Comparable results were obtained in HIV-positive subjects with CD4+ lymphocyte counts > 500 microliters-1, whereas impaired reactivity was found in HIV-positive volunteers with CD4+ counts < 500 microliters-1. Booster vaccination did not increase antibody levels in any of the groups studied, although the data did not exclude a positive influence of a second vaccine dose on persistence of antibody at 120 days after the first dose. No significant changes were observed in p24 antigenemia levels in HIV-positive individuals after vaccination.

Adult↗
PubMed1995

Role of antigenemia assay in the early diagnosis and prediction of human cytomegalovirus organ involvement in AIDS patients.

The role of an antigenemia assay in the diagnosis and prediction of human cytomegalovirus (HCMV) disease in AIDS patients was evaluated. The clinical history of 62 patients with advanced HIV infection from whom a total of 248 blood samples were drawn and tested by the HCMV antigenemia assay was examined retrospectively. Between December 1992 and January 1994, 28 episodes of HCMV disease with organ involvement were recorded; the antigenemia assay was positive in 23 of them (82.1%). In particular, this test was positive in 11 of 12 (91.6%) first episodes and in 3 of 3 (100%) recurrent episodes occurring in patients not receiving maintenance therapy. The same test was positive in 9 of 13 (69.2%) recurrent episodes occurring in patients receiving maintenance therapy. The first occurrence of HCMV disease was always preceded by a positive antigenemia assay 2 and 4 months before diagnosis (in all 7 patients of the 7 for whom a blood sample was available before HCMV disease). A positive antigenemia test result was not always followed by organ involvement, but a high positive cell count (> 100/200,000 polymorphonuclear leukocytes) strongly correlated with the appearance of HCMV disease in the following 1 to 3 months (100% of cases). The antigenemia assay is a useful and reliable indirect method for the diagnosis and prediction of HCMV end-organ disease in severely and persistently immunocompromised AIDS patients.

AIDS-Related Opportunistic Infections↗
PubMed1995

Quantification of nucleolar organiser regions in canine perianal gland tumours.

The proliferative activity in 28 canine perianal gland tumours was examined by the quantitative evaluation of the nucleolar organiser regions associated with argyrophil proteins (AgNORs). These regions were stained with a specific silver stain and quantified directly by light microscopy and by computerised image analysis. The relationships between some of the parameters used (the number of AgNORs per nucleus, the area of AgNORs per nucleus and the ratio of the area of AgNORs to the area of the nucleus) were also examined in relation to the histopathological grades of the tumours. All the parameters showed a high correspondence with the tumours' proliferative activity, and the ratio of the area of AgNORs to the area of the nucleus was the most significantly correlated with the tumours' histological patterns.

Adenocarcinoma↗
PubMed1995

Laminin expression in testicular tumours of the dog.

The expression of laminin was studied to determine the distribution pattern of basement membranes (BMs) in normal testes and in a series of 40 canine testicular tumours (seminomas, Leydig and Sertoli cell tumours). BM was always present around seminiferous tubules and blood vessels in normal testes and in seminomas and Sertoli cell tumours of the intratubular type without invasion. BM changes (fragmentation or loss, or both) were usually found in invasive neoplasms which retained their tubular structure; disruption or absence was observed in tumours, with a diffuse pattern. The BM was never expressed in Leydig cell tumours, except around vessels, irrespective of their histological growth pattern (cystic-vascular, pseudoadenomatous, diffuse). An attempt was made to relate the degree of BM modification to proliferative monoclonal antibodies and mitotic index. In parallel with the progressive loss of BM an increase in proliferative activity occurred, indicating that BM changes are additional useful prognostic indicators in testicular tumours of the dog.

Animals↗
PubMed1995

Detection of proliferating cell nuclear antigen (PCNA) in canine and feline mammary tumours.

Quantitation of immunohistochemical staining of the proliferating cell nuclear antigen (PCNA, clone PC10) by image analysis was performed on benign and malignant mammary tumours of dogs and cats. Scoring of the slides was carried out by image analysis to assess the percentage of labelled nuclei (expressed as a ratio of areas). Either the strongly labelled nuclei (SP-PCNA index), or all of the stained nuclei (TP-PCNA index) were counted as positive to determine the growth fraction and its correlation with the histopathological classification and nuclear grade (degree of nuclear differentiation, considered a morphological correlate of tumour aggressiveness). A significant difference in the values of PCNA indices was seen between benign and malignant growths (P < 0.0001, dog; P < 0.05, cat). Neither of the PCNA indices showed correlation with nuclear grade in dogs (P = 0.14 for SP-PCNA index and P = 0.31 for TP-PCNA index) or cats (P = 0.09 for SP-PCNA index and P = 0.07 for TP-PCNA index). A significant difference in the number of mitoses, expressed as mitotic index, was seen between benign and malignant growths in the dog (P < 0.01) but not in the cat (P = 0.078). Good correlation of mitotic index with nuclear grade was revealed in canine malignant growths (P < 0.05), but in feline malignant tumours such correlation (P < 0.05) was shown only when the values of intermediate plus typical forms were compared with the data for atypical forms. It is concluded that quantitation of PCNA-positive nuclear area by image analysis provides an objective method for assessing proliferative activity in benign and malignant mammary tumours of dogs and cats.

Adenocarcinoma↗