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Biomedical subjects

C Castaldini

Publications and source records attributed to C Castaldini.

27 records · Page 2Linked to original sources

Stromal cells in primary myelofibrosis: ultrastructural observations.

The bone marrows of five patients with primary myelofibrosis at different stages of the disease have been studied. In the myelofibrotic bone marrow, associated with "reticulum cells", two other cell types have been identified, namely fibroblast-like and myofibroblast-like reticulum cells, as well as a spectrum of transitional forms. Our findings suggest that reticulum cells may represent a reserve stromal cell pool (i.e. primitive reticulum cells) able to modulate themselves and to transform differently according to functional requirements. Some suggestions regarding the functional significance of fibroblast-like and myofibroblast-like reticulum cells in primary myelofibrosis are suggested.

Biopsy↗

Sequential behaviour of extracellular matrix glycoproteins in an experimental model of hepatic fibrosis.

The behaviour of extracellular matrix glycoproteins (fibronectin, laminin, basement membrane heparan-sulphate proteoglycan, type III, IV and V collagens) has been investigated in a sequential model of experimental hepatic fibrosis, using an immunofluorescence technique. The presence of some basement membrane macromolecules (such as type IV and V collagens, laminin and basement membrane heparan-sulphate proteoglycan) is detectable only in the early stages of septa formation, while type III collagen and fibronectin persist in late septa. These data suggest that hepatic fibroplasia proceeds through different steps in which stromal glycoproteins are preferentially engaged, as happens during organogenesis.

Animals↗

[The distribution of peroxidase-positive granuloblastic precursors of normal human bone marrow separated in discontinuous albumin gradient density].

Human normal marrow cells from 5 donors have been separated via discontinuous density gradient according to the Dicke's technique and the morphology of granulocytic cells recovered from density fractions has been examined; peroxidase negative myeloblasts are concentrated in low density fractions (specific density below 1.063), while granulated myeloblasts (peroxidase positive) are concentrated at densities ranging between 1.063 and 1.073; promyelocytes and myelocytes have been observed in all fractions although their maximal concentration is at density 1.073; metamyelocytes and polymorphonucleated cells are concentrated in the highest density fraction (density 1.078); some differentiated cells which are peroxidase negative have been observed; they concentrate at a density lower than that of peroxidase positive cells which look morphologically identical.

Bone Marrow Cells↗

[Growth in vitro of human bone marrow after freezing in liquid nitrogen: analysis of a case].

Human marrow is frozen according to the Schafer's technique; CFU-C proliferation and differentiation is then evaluated in relation to the time of storage in liquid nitrogen and to the time of in vitro culture in agar system according to the Pike and Robinson's technique. The highest plating efficiency is observed at the twelfth day of culture while in fresh cell suspension the growth peaks at the eighth day.

Bone Marrow Cells↗

bcl-2 protein expression in cervical intraepithelial neoplasia: no evidence of a prognostic significance in mild and moderate lesions.

BACKGROUND: The bcl-2 proto-oncogene codes for a protein which appears to block apoptosis. In our study, we examined bcl-2 protein expression in cervical squamous metaplasia, cervical intraepithelial neoplasia (CIN) and microinvasive squamous carcinoma with the aim of identifying a relationship between bcl-2 protein expression and neoplastic development and progression. MATERIALS AND METHODS: Cervical bioptic samples were obtained from 86 white women, selected consecutively from our Colposcopic Service from January 1993 to June 1994, because of abnormal pap- smear suspicious for cervical dysplasia and/or human papilloma virus (HPV) infection. Upon histologic evaluation, 41 women had CIN, 23 cervical condyloma, and 22 squamous metaplasia. Ten patients with microinvasive squamous carcinoma, matched for age and demographic characteristics, were selected from our series of invasive cervical carcinomas and immunohistochemically analyzed. The expression of primary tumor bcl-2 protein was immunohistochemically evaluated by antihuman bcl-2 monoclonal antibody (diluted 1:100, Dako, Copenhagen, Denmark) on formalin-fixed paraffin-embedded tissue. Positive staining was expressed as a percentage of positive cells per 1000 counted dysplastic cells for each case. RESULTS: Bcl-2 immunostaining was found in all the 22 squamous metaplasias, limited to the basal layer. Nineteen of the 41 CINs (46%) were bcl-2 immunoreactive, and 2 of the 10 microinvasive carcinomas (20%). By analysing CIN lesions, the bcl-2 protein showed a striking increase in the rate of positivity with increasing severity of CIN; the bcl-2 protein expression in CINs III was significantly higher than for CINs I, CINs II or microinvasive carcinomas (P = 0.03, P = 0.02, and P = 0.03 respectively). No relationship was observed between bcl-2 immunostaining and HPV infection. bcl-2 protein expression was not useful for predicting CIN I and II evolution, although the rate of persistence/progression was higher in bcl-2 positive dysplasias (7 of 9 cases, 78%) than in negative ones (13 of 21 cases, 62%) (p = 0.88). CONCLUSIONS: Based on these results, it seems possible that the increase in bcl-2 expression in higher grade of CINs implies an increasing protection against programmed cell death, but also the induction of genetic instability in dysplastic epithelial cells and a greater capacity to evolve into invasive carcinoma.

Adult↗

Immunohistochemical evaluation of type IV collagenase (72-kd metalloproteinase) in prostatic intraepithelial neoplasia.

The aim of this study was to investigate the expression of type IV collagenase (72-kd metalloproteinase, MMP-2) in prostatic intraepithelial neoplasia (PIN) in relation to normal prostate (NP) and prostatic adenocarcinoma (PAc). Twenty formalin-fixed, paraffin-embedded prostatectomy specimens, in which NP, PIN and PAc were present, were immunohistochemically examined. The NP ducts and acini not contiguous with PIN and PAc showed slight MMP-2 immunostaining in the secretory cells, with some increase in intensity at the apical border, and moderate to strong immunoreactivity of some basal cells. In NP adjacent to PIN and PAc, rare ducts and acini showed strongly stained cells either isolated or in small groups of two, located within the thickness of the epithelium, close to the basement membrane. In the majority of PIN ducts and acini, the stratified secretory cells showed moderate staining. Most of these ducts and acini also showed strongly stained cells, which were mostly isolated, and either in contact with the basement membrane or scattered among the secretory cells. Low and high grade PIN showed some difference in the frequency of dark cells, which were more numerous in the latter. A small group of neoplastic acini adjacent to high grade PIN (early invasive adenocarcinoma) was observed in one of the 20 cases. Intense immunostaining was present in the acini originating from the PIN lesion. MMP-2 immunostaining of PAc was heterogeneous in intensity and location. Cribriform and solid/trabecular PAc showed weak cytoplasmic immunostaining; both moderately and intensely stained cells were seen in the cell layer adjacent to the stroma, intense immunostaining was shown by small clusters of neoplastic cells or single neoplastic cells located in the stroma. In acinar PAc, weak cytoplasmic immunostaining for MMP-2 was seen throughout most areas of the tumours, whereas moderately and intensely stained cells were observed less frequently than in cribriform and solid/trabecular adenocarcinoma. Intense immunostaining of single or small clusters of neoplastic cells located in the stroma was occasionally observed and, as with cribriform and solid/trabecular PAc, mainly located towards the periphery of the tumour nodules. Occasional ducts and acini with PIN and foci of PAc were either completely negative or very weakly stained. In conclusion, MMP-2 immunostaining increases progressively from NP, through PIN, up to invasive PAc. These results directly support the hypothesis that increased expression of metalloproteinases is a marker of malignant conversion.

Adenocarcinoma↗