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C Di Loreto

Publications and source records attributed to C Di Loreto.

At least 55 records · Page 3Linked to original sources
PubMed1996

Large core biopsy for diagnostic and prognostic evaluation of invasive breast carcinomas.

Large core biopsy is a recently introduced method for pre-operative evaluation of breast lumps. The aim of this study was to evaluate the usefulness of this technique in providing pre-operative diagnostic and prognostic information that can lead to a correct line of treatment. We compared 41 cases of breast carcinomas diagnosed both by core biopsies and surgically removed samples. A high (93%) diagnostic agreement was obtained. Moreover, we found a significant correlation for mitotic count (r = 0.76), oestrogen receptor (r = 0.78), progesterone receptor (r = 0.80), p53 (r = 0.86) and c-erbB-2 (r = 0.90) analysis between core biopsy and definitive surgical pathology. An agreement for histological grading evaluation between the two techniques was obtained in 32 out of 40 cases (k = 0.65) whereas in the other cases, a lower grade was assigned by evaluating core biopsies. These findings suggest that percutaneous core breast biopsy is a valid tool for pre-operative management of breast lesions, but this should be confirmed in larger, prospective studies.

Adult↗
PubMed1996

Widespread clonal B-cell disorder in Sjögren's syndrome predisposing to Helicobacter pylori-related gastric lymphoma.

Helicobacter pylori has been identified as a critical antigenic stimulus to the development of gastric lymphoma, but additional factors should be required for such evolution. This topic is now of major importance to clarify the pathobiology of gastric lymphomagenesis. Peculiar autoimmune diseases, such as Sjögren's syndrome, are well known to predispose to B-cell lymphomas. We report on a patient with Sjögren's syndrome and a widespread B-cell lymphoproliferative disorder. A pathological picture of low-grade lymphoma was observed in the stomach, concomitantly with H. pylori infection. However, the B-cell disorder was definitely nonmalignant in the other tissues involved, i.e., the parotid gland and lymph nodes, which are the characteristic targets of Sjögren's syndrome-associated lymphoproliferation. After H. pylori eradication, a dramatic regression of gastric lymphoma into chronic gastritis was observed, but no amelioration occurred in the parotid and nodal involvement. Multiple molecular analyses showed the expansion of the same B-cell clone in synchronous and metachronous lymph node, parotid, and gastric lesions before and after H. pylori eradication. Thus, H. pylori played a crucial role in the local boosting of B-cell lymphoproliferation, but the underlying B-cell disorder was that associated with the autoimmune disease and was nonmalignant. The comprehensive clinical, pathological, and molecular approach allowed us to then distinguish the role of peculiar individual predisposing factors and of local infection in the pathobiology of mucosa-associated lymphoid tissue-associated lymphoproliferation.

Aged↗
PubMed1996

Expression of p53 and bcl-2 and response to preoperative chemotherapy and radiotherapy for locally advanced squamous cell carcinoma of the oesophagus.

AIMS: To investigate the immunohistochemical expression of p53 and bcl-2 proteins in squamous cell carcinoma (SCC) of the oesophagus and to assess whether expression of these oncoproteins can be used to stratify patients into groups with a favourable or unfavourable response to preoperative chemo/radiotherapy. METHODS: The initial diagnostic biopsy and the corresponding resected samples were obtained from 22 consecutive patients with SCC. All patients underwent preoperative chemo/radiotherapy. Tumour sections were incubated with a monoclonal antibody directed against p53 (DO-7). Twenty four non-neoplastic oesophageal biopsy specimens immunostained for p53 served as controls. Twelve randomly chosen sections from the 22 SCC samples were immunostained to test for bcl-2 protein expression. RESULTS: After chemo/radiotherapy, 12 (55%) of the 22 patients had no evidence of tumour in the resected oesophagus. Before chemoradiotherapy, however, 17 (77%) patients were p53 positive. After treatment, residual carcinoma was detected in seven (41%) of the 17 p53 positive patients. All non-responsive cases had the same p53 immunopattern as before treatment. Bcl-2 immunoexpression was detected in six (50%) of 12 patients. Residual tumour was detected in the residual oesophagus in two (33%) of the six bcl-2 positive patients. After treatment, bcl-2 expression was no longer detected in the residual neoplastic cells of a previously bcl-2 positive tumour. Using Fisher's exact test no significant association was found between oncoprotein expression and response to preoperative treatment. CONCLUSION: This study confirms the observation that p53 protein is frequently expressed in SCCs of the oesophagus, probably as a result of a mutation of the TP53 gene. However, no significant association was found between oncoprotein expression and response to chemo/radiotherapy. Anticancer agents do not seem to modify the expression of p53 and bcl-2 proteins.

Adult↗
PubMed1996

B cell lymphoma of the thymus and salivary gland.

A case of primary low grade B cell lymphoma of the salivary gland associated with a low grade B cell lymphoma of the thymus and involvement of the skin is reported. The lesions in the salivary gland and in the thymus showed the typical features of a lymphoma arising from the mucosa associated lymphoid tissue (MALT) and comprised lymphatic follicles, centrocyte-like (CCL) cells and lymphoepithelial lesions. Immunohistochemistry and Southern blot analysis supported the hypothesis that these lesions can originate from the same cellular clone. These findings confirm the occurrence of low grade B cell MALT lymphoma in the thymus and the possibility of spread of MALT lymphoma to other mucosal sites.

Blotting, Southern↗
PubMed1994

Expression of thyroid-specific transcription factors TTF-1 and PAX-8 in human thyroid neoplasms.

TTF-1 and PAX-8 are tissue-specific transcription factors expressed in the thyroid follicular cells, contributing to the maintenance of the differentiated phenotype. In fact, it has been demonstrated that TTF-1 and PAX-8 are able to activate transcription from thyroglobulin and thyroperoxidase (TPO) promoters, the transcriptional activity of which is in vivo restricted only to the thyroid follicular cell. In order to gain insight into how these transcription factors control in vivo the differentiation of the thyroid cell and to have a better molecular characterization of human thyroid tumors, TTF-1, PAX-8, thyroglobulin, and TPO mRNA levels were measured in nonmalignant and malignant human thyroid tissues. Results indicate that the expression of TTF-1 and PAX-8 is not sufficient per se for the expression of the thyroid-differentiated phenotype. Furthermore, in follicular adenomas, PAX-8 mRNA levels are strictly related to TPO mRNA levels, suggesting that the amount of PAX-8 could play a role in the modulation of TPO gene expression. TTF-1 mRNA is always well detectable in papillary carcinomas and, in contrast, always absent in anaplastic carcinomas. Identical results were obtained when the expression of TTF-1 protein was investigated using immunohistochemistry. Thus, TTF-1 gene expression could be a molecular marker in order to distinguish these two types of thyroid neoplasms.

Adenocarcinoma, Follicular↗
PubMed1994

Transforming growth factor-beta 1 is more expressed in thyroid follicular adenoma than in normal tissue.

It is well known that TSH is the main factor responsible for thyrocyte proliferation and growth. Recent studies have shown that other growth factors, including transforming growth factor-beta 1 (TGF-beta 1), have an important role in the control of thyrocyte proliferation and differentiation. The aim of the study was to evaluate the expression of the TGF-beta 1 gene in thyroid follicular adenoma (FA) by Northern analysis, and its protein localization by immunohistochemistry. Surgically removed thyroid tissue from 56 patients with thyroid FA was screened for the study. Normal thyroid tissue from 4 patients with papillary carcinoma was used as a control. Sixteen FA (8 with a "cold" and 8 with a "hot" scintiscan pattern) having homogeneous histological characteristics were subsequently selected. FA showed greater TGF-beta 1 gene expression than control tissue. There was not a statistically significant difference between "cold" and "hot" FA. Immunohistochemistry analysis showed that TGF-beta 1 was located in various histological structures of the adenomas (thyrocytes, endothelium, perinervium and connective tissue); on the other hand, perinodular and control tissue did not show appreciable TGF-beta 1 protein. Our data suggest that TGF-beta 1 may be involved in the pathogenesis of FA. The different TGF-beta 1 distribution in thyrocytes, endothelium, perinervium and connective tissue in FA suggests that TGF-beta 1 may be variably expressed during the natural history of FA. Since no significant difference in TGF-beta 1 gene expression between "hot" and "cold" adenomas was found, it appears that other factors are involved in their functional differentiation.

Adenoma↗
PubMed1993

Immunohistochemical localization of intracellular and extracellular associated TGF beta in the skin of patients with systemic sclerosis (scleroderma) and primary Raynaud's phenomenon.

We have investigated the distribution of TGF beta using antibodies specific for its intracellular and extracellular forms in full-thickness biopsies of patients with SSc, primary Raynaud's phenomenon (PRP), systemic lupus erythematosus (SLE), and from normal subjects. Nine of 11 SSc biopsies demonstrated intracellular TGF beta in endothelial cells while only 6 exhibited extracellular TGF beta. Endothelial cells in skin biopsies of all PRP patients displayed both intracellular and extracellular TGF beta. All other control biopsies were negative. In patients with PRP, some positively staining fibroblasts were found scattered throughout the dermis. Lastly, extracellular TGF beta was localized in the papillary dermis of PRP and SSc biopsies and in all the dermal layers of SLE patients. No significant staining of TGF beta was observed in the endothelial cells, fibroblasts, or in the extracellular matrix of the majority of biopsies from normal subjects. These data suggest that TGF beta may be one of the cytokines involved in the early stages of pathogenesis of SSc, and that endothelial cells in SSc and PRP may be a source and/or a target of TGF beta.

Aged↗
PubMed1990

[Biology and differentiation of lymphocytes in the classification of lymphomas].

The classifications of non-Hodgkin's lymphomas are briefly discussed and the processes of proliferation and differentiation of B and T lymphocytes are analyzed. The B and T lymphocytes engaged in the immune response arise from precursor cells through a two-cycle process of proliferation and differentiation: the first cycle produces cells with antigen receptors of varying specificity (resting circulating B and T lymphocytes); the second cycle produces B and T type effector cells and "memory" cells. Each phase of B and T differentiation can give rise to a type of lymphoma; in fact, malignant lymphomas can be divided into categories of precursor B and T cell lymphomas, resting B and T cell lymphomas and activated B and T cell lymphomas. Hodgkin's lymphoma could be considered a lymphoma arising from activated cells with atypical phenotype, i.e. Hodgkin and Reed-Sternberg cells. These cells secrete cytokines which recruit lymphocytes, histiocytes, eosinophils and plasma cells which form the cellular background typical of this tumor.

B-Lymphocytes↗
PubMed1989

Multiparametric quantitation of the progression of uterine cervix preneoplasia towards neoplasia.

The aim of the research was to quantify the malignancy progression of preneoplastic lesions towards carcinoma of the uterine cervix. The study has shown that the modifications to nuclear area, perimeter, DNA content, percentage of nuclei with nucleoli, nuclear/cytoplasmic ratio and percentage of SOYA BEAN AGGLUTININ stained cells are progressively greater moving from normal epithelium and mild dysplasia towards infiltrating carcinoma. In particular all the morphologic and histochemical parameters have shown an increasing derangement which appears to parallel the diploid reduction and the appearance of aneuploidy. In order to identify the changes in the stroma, the modifications to the capillaries were investigated: in mild dysplasia only the vessel density increases; the capillary area, perimeter and diameter increase in moderate and severe dysplasia, and in CIS; the values of these features are similar in the carcinoma groups. The capillary density increases mainly in the invasive carcinoma. The data obtained in the study have shown that: 1) the process of malignancy progression is characterised by a gradual and continuous derangement of cell characteristics and modifications to capillaries of the stroma; 2) the mild dysplastic changes have the characteristics of hyperplastic lesions; 3) CIS, qualitatively similar to severe dysplasia from which it differs quantitatively, has features of neoplastic proliferation; 4) the appearance of invasion is associated with DNA parameter changes which may indicate a ploidy reduction.

Capillaries↗
PubMed1989

Immunocytochemistry of anaplastic carcinoma of thyroid gland.

Twelve anaplastic thyroid carcinomas were investigated with a panel of antibodies. The squamoid and giant cell anaplastic carcinomas showed coexpression of cytokeratin and vimentin in 66% of the cases. Reactivity for A-1-AT and A-1-ACT antiserum appeared when the spindle cell component became prevalent. The antidesmoplakin antibody can be employed on cryostat sections in differential diagnosis between sarcoma and carcinoma of the thyroid.

Adult↗
PubMed1989

Immunohistochemical characterization and distribution of Langerhans cells in normal epithelium of the uterine cervix.

Langerhans cells (LCs) were shown up in normal cervical tissue obtained from 32 women whose age ranged from 25 to 68 years, using immunohistological methods. LCs were detected in metaplastic and native squamous epithelium of the cervix; they were positive to Dako-LC and OKDR antibodies and those located in the basal-suprabasal epithelial layers were also OKT6-positive. The density of the LCs was higher during the proliferative phase of the menstrual cycle. The investigation into the lymphocytes present in the stroma and in the squamous epithelium showed a population of T-lymphocytes identified as predominantly T-cytotoxic/suppressor cells, sometimes in contact with LCs. The significance of these findings is discussed.

Adult↗
PubMed1987

Different binding to squamous and columnar epithelium of the uterine cervix as a marker of epithelial differentiation.

Biotinylated lectins were used to investigate the expression of carbohydrate residues on columnar and squamous epithelium of the uterine cervix. Con A, WGA, RCA I, PNA, UEA I, DBA and SBA were used. In the native exocervical and in metaplastic squamous epithelium of the transformation zone, one group of lectins (Con A, WGA, RCA I and PNA) stained the cell periphery of all epithelial layers. A second group (UEA I, DBA and SBA) colored the cell periphery of the suprabasal cells. The basal layer was always negative. All lectins labeled the apical border and occasionally the cytoplasm of the endocervical columnar epithelium. Lectin-binding of metaplastic and native squamous epithelium could possibly be used as a marker of epithelial differentiation in normal and abnormal conditions.

Adult↗
PubMed1984

Experience with the Oxford tumour marker in uterine cervical lesions.

The Ca 1 antibody has been tested with an immunoperoxidase technique in sections of uterine cervix embedded in paraffin wax. Examined samples included normal or metaplastic epithelium, mild, moderate and severe dysplasia, carcinoma in situ and invasive squamous cell carcinoma. The Ca 1 antibody reacted with the normal or metaplastic transformation-zone epithelium and with dysplastic and neoplastic lesions. It is concluded that this antibody is not useful in the diagnosis of cervical malignancy.

Antibodies↗