Dynamic Conditional Correlation with Elliptical Distributions

The Dynamic Conditional Correlation model of Engle has made the estimation of multivariate GARCH models feasible for reasonably big vectors of securities’ returns. In the present paper we show how Engle’s twosteps estimate of the model can be easily extended to elliptical conditional distributions and apply different leptokurtic DCC models to some stocks listed at the Milan Stock Exchange. A free software written by the authors to carry out all the required computations is presented as well.Multivariate GARCH, Dynamic conditional correlation, Generalized method of moments

Immunohistochemical investigation of PNL2 reactivity of canine melanocytic neoplasms and comparison with Melan A

PNL2 is a recently generated monoclonal antibody (mAb) that recognizes normal and neoplastic melanocytes. Although the antigen recognized by PNL2 remains unknown, recent studies of human and mouse melanomas have confirmed its usefulness as a diagnostic marker. In the current study, the immunoreactivity of PNL2 in canine melanomas was tested and compared with Melan A (A103). Validation of PNL2 was performed by Western blot analysis. PNL2 and Melan A immunoreactivity were tested on frozen samples of canine melanomas and on 69 formalin-fixed, paraffin-embedded melanocytic neoplasms. Normal canine tissues and nonmelanocytic neoplasms were included as negative controls. Western blot confirmed the presence of a protein recognized by the PNL2 antibody in canine melanomas. Immunohistochemically, PNL2 stained the melanocytic neoplastic cells with an intracytoplasmic, granular pattern. Among the melanocytic neoplasms tested, 62% stained positively with PNL2 and 59% with Melan A; 50.7% stained positively with both mAbs. The overall percentage of neoplasms that stained positively with at least 1 of these 2 antibodies was 68%. The extent of staining (i.e., the percentage of cells stained per specimen) was greater with PNL2 than with Melan A. With both mAbs, staining was most intense and diffuse in the epithelioid cell phenotype. Neither nonspecific staining nor staining in cells other than melanocytes was detected with either mAb. In contrast to human granulocytes, canine granulocytes were negative by both Western blot and immunohistochemical analyses. PNL2 mAb proved to be highly specific for the identification of formalin-fixed canine melanocytic neoplasms and should be a valuable diagnostic reagent

Probable role of Brain Natriuretic Peptide (BNP) in lung hypertension secondary to scleroderma

BACKGROUND Scleroderma, when complicated with pulmonary hypertension (PHT), presents a worse prognosis; recently treatment with new drugs seems to offer good perspectives, especially in early diagnosis and treatment. The standard approach for diagnosing PHT consists in measurement of the pulmonary artery pressure (PAP) by means of echodoppler. AIM OF INVESTIGATION Aim of this work is evaluating the significance of the NT-proBNP parameter, matched to echodoppler, in diagnosing scleroderma PHT. MATERIALS AND METHODS Sixty (60) patients, who came to observation for progressive systemic sclerosis underwent echodoppler in order to measure the PAP (normal values up to 30 mmHg). NT-proBNP was determined on serum sample using ECLIA method by Modular E170 (Roche Diagnostics); manufacturer reference values for age and gender were used. Forty-three (43) patients underwent a further NT-proBNP sampling 5 days later in order to assess parameter stability. RESULTS PHT and non- PHT patients showed statistically different (p < 0,001) medians (126 vs 69 pg/ml). No pathologic values of NT-proBNP were measured in the group with PAP < 30 mmHg, while 27% of cases who had PAP between 30 and 40 showed pathologic concentrations. The positivity ratio increases to 57% in patients showing PAP > 40 mmHg. No relevant correlation (r = 0,2) was found between PAP and NT-proBNP. Mean average between the two sampling groups was 31%. CONCLUSIONS In scleroderma patients, combination of NT-proBNP and PAP seems to improve the diagnosis of pulmonary hypertension, especially in presence of borderline pulmonary pressure values. We therefore propose the biochemical observation of NT-proBNP when PAP is > 30 mmHg and in monitoring the evolution of the pathology

LTA4H and FXR1 Gene and Protein Expression in Canine Oral Melanoma

Introduction: Canine oral melanoma is a common neoplasm that is usually considered malignant, although the correlation between histology and prognosis is still controversial. Therefore, research of new biological markers is ongoing. In this study, LTA4H (an enzyme of the arachidonic acid cascade) and FXR1 (a RNA binding protein) are investigated. Both have been investigated previously for their possible role in metastasis of ocular melanoma, and are studied here in canine oral melanoma. Materials and Methods: Twenty-nine samples of formalin-fixed and paraffin wax-embedded canine oral melanomas were analyzed. Routine HE sections were evaluated on light microscopy and received a histological description, including mitotic activity index (MI). Immunohistochemistry (IHC) for LTA4H, FXR1 and Ki67 was performed. LTA4H and FXR1 were scored semiquantitatively and Ki67 was scored quantitatively. The expression of LTA4H and FXR1 genes was also quantified by RT-PCR. Results: Most of the cases were epithelioid, poorly pigmented melanomas. MI ranged from 0.1 to 9.2 (median 1.1). Ki67 index ranged from 7.9 to 44.4% (median 19%). IHC was positive in 29/29 LTA4H and 28/29 FXR1, with variable intensity and percentage of positivity. RT-PCR relative expression values ranged from 0.49 to 9.11 for LTA4H and 0.15 to 10.33 for FXR1 (in four cases was under the detection limit). Conclusions: LTA4H and FXR1 were detected in all tested melanomas. Marked differences between cases were noted with RT-PCR, although target gene expression levels were not consistent with histological parameters or Ki67 index. Conversely, immunohistochemical positivity was elevated in most cases with negligible expression differences. Further work is ongoing to clarify the prognostic significance of different levels of expression

Identification of bovine doppel protein in testis, ovary and ejaculated spermatozoa

Doppel (Dpl) protein is a recently identified prion-like protein. Although Dpl might be expressed in the brain after prion gene deletion, in both human and mice Dpl is normally expressed only in testis and spermatozoa, where it appears to be involved in male fertility. Little information is available so far about the expression pattern of Dpl in bovines, thus, hampering possible research on the role of this protein in bovine infertility. We have thus, designed, produced and validated through Western blotting a polyclonal antibody against bovine Dpl. With this antibody we then screened bovine tissues for Dpl expression by immunohistochemistry. Ejaculated spermatozoa were screened by flow cytometry and immunocytochemistry. Bovine Dpl was expressed in all the developing stages of germinal cells, from spermatogones to ejaculated spermatozoa, in Sertoli cells and in ovarian follicles (granulosa cells and follicular fluid). Dpl immunoreactivity was also found on other tissues, where endothelial cells, peripheral nerves and scattered lymphocytes stained positive. This distribution pattern suggests that Dpl might be involved in sperm maturation/capacitation in bovines, like it might be in mice. This hypothesis needs to be verified by widespread application of the flow cytometric protocol established in this paper on spermatozoa from animals with reduced fertility

Automated tru-cut imaging-guided core needle biopsy of canine orbital neoplasia. A prospective feasibility study

The purpose of this study was to evaluate the diagnostic value of imaging-guided core needle biopsy for canine orbital mass diagnosis. A second excisional biopsy obtained during surgery or necropsy was used as the reference standard. A prospective feasibility study was conducted in 23 canine orbital masses at a single centre. A complete ophthalmic examination was always followed by orbital ultrasound and computed tomography (CT) examination of the head. All masses were sampled with the patient still on the CT table using ultrasound (US) guided automatic tru-cut device. The most suitable sampling approach to the orbit was chosen each time based on the CT image analysis. One of the following different approaches was used: trans-orbital, trans-conjunctival or trans-masseteric. In all cases, the imaging-guided biopsy provided a sufficient amount of tissue for the histopathological diagnosis, which concurred with the biopsies obtained using the excisional technique. CT examination was essential for morphological diagnosis and provided detailed topographic information that allowed us to choose the safest orbital approach for the biopsy. US guided automatic tru-cut biopsy based on CT images, performed with patient still on the CT table, resulted in a minimally invasive, relatively easy, and accurate diagnostic procedure in dogs with orbital masses.Keywords: Computed tomography, Core-needle biopsy, Dogs, Orbital mass, Ultrasoun