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P G Betta

Publications and source records attributed to P G Betta.

At least 19 recordsLinked to original sources
PubMed2000

Interleukin-2 induces cell cycle perturbations leading to cell growth inhibition and death in malignant mesothelioma cells in vitro.

Previous report indicated that Interleukin-2 (IL-2) is able to inhibit the growth of IL-2-receptor-positive cancer cell lines without any involvement of the immune system, through IL-2-induced alterations of the cell cycle kinetics. In this study we provide evidence that IL-2 exerts anti-proliferative effect on three human malignant mesothelioma (MMe) cells in vitro, while no effects were observed on normal human mesothelial cell (HMC) primary cultures. The growth inhibitory effect of IL-2 on neoplastic cells appeared to depend on the baseline proliferative status of these cells. Indeed, in highly proliferating MMe cells, we observed a reduction of malignant cells in the S-phase of the cell cycle, with an accumulation in G0/G1, followed by apotosis for longer incubations or exposure to higher doses. On the contrary, in MMe cells proliferating at lower rate, IL-2 induces only a late cytotoxic effect, leading to apoptosis, without significantly affecting the cell cycle. IL-2Rbeta mRNA was detectable by RT-PCR in all MMe cells, IL-2Ralpha mRNA in one only out the three assayed and IL-2Rgamma mRNA in none. In addition, mRNA specific for the IL-2Rbeta-associated Jak-1 tyrosine kinase was expressed in all MMe cell lines, further suggesting that IL-2Rbeta may play a role in the observed effects. Very low, albeit detectable, levels of IL-2Rbeta chain appeared to be expressed at the cell surface of MMe cells by indirect immunofluorescence and FACS analyses. Finally, Ca(++) fluxes were rapidly induced when MMe cells were exposed to exogenous IL-2.

Apoptosis↗
PubMed1999

Establishment of four new mesothelioma cell lines: characterization by ultrastructural and immunophenotypic analysis.

The aim of this study was to assess the biological characteristics of four new malignant mesothelioma (MM) cell lines. Since simian virus (SV)40 sequences have been recently detected in MM, SV40 large T antigen (Tag) expression was also analysed. MM cell lines were characterized by morphological, ultrastructural and cytogenetic analysis. Expression of Tag and of relevant MM markers was studied by immunocytochemistry, surface antigens by indirect immunofluorescence and immunomodulating cytokines by enzyme-linked immunosorbent assay (ELISA). The four MM cell lines, established from pleural effusions, showed a slow proliferation rate and pleomorphic changes during culture. Cell lines expressed vimentin, cytokeratins 8 and 18, and the mesothelial antigen recognized by HBME-1 monoclonal antibody, but not carcinoembryonic antigen. Surface human leukocyte antigen (HLA)-class I and intercellular adhesion molecule (ICAM)-1 molecules were present on all the cell lines. While HLA class II and CD86 were constitutively undetectable, HLA-class II was present after interferon (IFN)-gamma stimulation. All cell lines displayed abnormal karyotypes with chromosome 6 abnormalities. Transforming growth factor (TGF)-beta2 and interleukin (IL)-6 were constitutively secreted, while tumour necrosis factor (TNF)-alpha was secreted only in response to lipopolysaccharide. Intranuclear Tag was expressed in two cell lines. The persistence of large T antigen with human leukocyte antigen class I and intercellular adhesion molecule-1 positivity may point to large T antigen as a target for cytotoxic T-lymphocyte-based immunotherapy in some malignant mesothelioma patients.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1998

Primary human mesothelioma cells express class II MHC, ICAM-1 and B7-2 and can present recall antigens to autologous blood lymphocytes.

Mesothelioma cells (MMc) are considered to be weakly immunogenic and the experimental approaches attempting to induce an immune response against these cells have been disappointing. Our aim was to investigate whether MMc possess the surface accessory molecules involved in antigen presentation and whether these cells are capable of presenting recall antigens to autologous blood lymphocytes. Four primary MMc cultures were generated from malignant effusions and examined to assess whether the accessory molecules required for antigen presentation were present on their surfaces. Intercellular adhesion molecule-I (ICAM-I; CD54); class I and class II major histocompatibility complex-DR (MHCI and MHCII-DR); B7-1 (CD80.3); and B7-2 (CD86) expression by MMc was studied by immunocytochemical and/or FACScan analysis. MMc were pulsed with purified protein derivative (PPD), Tetanus toxoid (TT) and Candida albicans (CA) bodies, and incubated with autologous lymphocytes. Lymphocyte proliferation was estimated by radionucleotide incorporation. Phenotypic analysis showed the presence of MHCII-DR, ICAM-I and B7-2 on primary MMc cultures, whereas the phenotypic evaluation of 2 established MMc lines did not show the presence of the B7-1 and B7-2 molecules. In addition, MHCII-DR was detectable only after interferon gamma (IFN-gamma) stimulation. Primary MMc cultures acquired the capability to induce lymphocyte proliferation after pulse with the recall antigens. To achieve characterization of these lymphocytes, we generated a PPD-specific CD4+ T-cell clone. PPD-pulsed MMc were shown to specifically induce T-cell clone proliferation through a MHCII-DR-mediated process. We conclude that primary MMc possess the surface molecules required for antigen presentation and can present recall antigens to CD4+ lymphocytes.

Aged↗
PubMed1998

The role of immunohistochemistry in the diagnosis of malignant mesothelioma.

Malignant mesothelioma (MM) can place the pathologist in a diagnostic dilemma because of its morphological variability. The contribution of immunohistochemistry to a more accurate recognition of the mesothelial histogenesis of serosal tumours is widely acknowledged. The immunohistochemical diagnosis of epithelial MM is currently mainly one of exclusion based on prevailing negative staining with several tissue markers of adenocarcinomatous differentiation. The contribution of immunohistochemistry to a definite diagnosis of MM has only been established for the sarcomatous forms, which are positively labelled by anticytokeratin antibodies. A few antimesothelial antibodies have been generated in recent years and two of them have recently been marketed although they have yet to be validated on a wide scale in routine laboratory practice. However, none of them appears a priori as the ideal single positive marker for an unequivocal diagnosis of MM.

Humans↗
PubMed1997

Newly marketed tissue markers for malignant mesothelioma: immunoreactivity of rabbit AMAD-2 antiserum compared with monoclonal antibody HBME-1 and a review of the literature on so-called antimesothelioma antibodies.

A complementary DNA (cDNA) library was constructed from a human malignant mesothelioma (MM) cell line and a cDNA fragment encoding for a cytoplasmic mesothelial protein recognized by the polyclonal antibody AMAD-1 was then cloned and expressed in Escherichia coli. The purified recombinant protein was used to raise a novel antibody, named AMAD-2, in rabbits. This antibody reacted with normal mesothelium and most MM (15 of 17) on paraffin sections and featured a cytoplasmic labeling. Conversely, AMAD-2 immunostaining of normal and tumor tissues from body sites other than serosal membranes was limited with respect to the proportion of positive specimens and usually less conspicuous than in MM. AMAD-2 immunoreactivity was subsequently compared with staining for HBME-1, another newly marketed antimesothelial monoclonal antibody, concerning the ability to distinguish pleural MM from metastatic pleural tumors of epithelial type. A granular cytoplasmic immunoreactivity for AMAD-2 was present in 50% or more of tumor cells in all 84 MM, regardless of histological type, but also in 3 (7%) of 42 pleural metastases, albeit only focally. HBME-1 was shown in 63 of 66 epithelial MM and in the epithelial component of all 8 mixed MM, with a prevailingly membranous pattern, usually homogeneous and strong, whereas none of the 10 sarcomatous MM was positive. HBME-1 was also expressed in 6 (14%) of 42 pleural metastases in a cytoplasmic or membranous pattern. Compared with HBME-1, AMAD-2 showed a higher degree of specificity and sensitivity for MM. AMAD-2 still proved to be superior to HBME-1, also when sarcomatoid MM were excluded from the assessment. This finding supports the view that AMAD-2 is an antibody highly, although not entirely, specific for the mesothelial lineage, whereas HBME-1 is probably a cell marker more closely related to the epithelial differentiation of MM. Therefore, AMAD-2 is preferable as a positive tissue marker to be incorporated in the optimal immunohistochemical panel for the diagnosis of MM.

Antibodies, Monoclonal↗
PubMed1997

Malignant mesothelioma of the pleura. The reproducibility of the immunohistological diagnosis.

The reproducibility of the histopathological diagnosis of pleural malignant mesothelioma (MM), after supplementing routine H&E stain by immunohistochemistry (IH) in 77 cases of original diagnoses of MM, was assessed by examining interobserver variation between five pathologists. A battery of commercial antibodies (cytokeratins, vimentin, HMFG-2, anti Leu-M1 [CD15], BerEP4, B72.3 [TAG-72], carcinoembyonic antigen), considered to be useful in enhancing diagnostic accuracy, was used. The number of definitively classified tumors (accepted MM plus rejected MM) increased from 57 on H&E stain to 60 after IH, with 59 (76.6%) cases being accepted as true MM. Based on IH, the chance-adjusted interobserver agreement was poor (kappa w = 0.29) and lower than that observed on previous H&E alone. The intraobserver agreement for four of the five pathologists was rather good (kappa w = 0.54-0.56). The inter- and intraobserver concordance was higher in accepting than excluding the cases as MM. A larger number of cases were classified by all reviewers as mixed or sarcomatous variants after IH. In the interpretation of each immunostain, kappa values ranged from 0.19 for B72.3 to 0.62 for HMFG-2, which were respectively the least and the most consistently interpreted immunostains. The information additionally contributed by IH did not seem to change the pathologists' diagnoses very much in comparison with those made by routine H&E stain. Until highly specific and sensitive probes for the positive identification of MM become available, a careful scrutiny of routinely stained preparations still remains the most rewarding component of the diagnostic pathway.

Clinical Laboratory Techniques↗
PubMed1997

[Cellular proliferation, expression of p53, EGFR and apoptosis index of healthy mucosa of the bladder with TCC; pre- and post-intravesical BCG immunohistochemical study].

At present, the most efficacious and used immunostimulant agent in the superficial bladder cancer immunotherapy field, is the BCG, even if its mechanism of action is still partly unknown. The therapeutic effects of BCG don't seem to depend exclusively on local immune response, so that according to this assertion, this immunohistochemical study had been conducted on 14 patients affected by superficial bladder cancer (pTa-pT1) which aimed to value both the apoptosis and proliferation indexes and the expression of the genetic product p53 and EGFR before and after the exposition of the vesical mucosa to the BCG. The BCG treatment can reduce the proliferation index of the normal urothelial cells in a statistically significant way whereas it would exclude a cytostatic effect mediate by negative modulation of EGFR from the cytokinins induced by BCG itself. The index of apoptosis of the urothelium does not increase after BCG and decreased expression of p53 associated after the treatment, although statistically not significant, it would seem to bear, the prophylactic efficacy of BCG according to the follow up of the patients included in the study.

Adjuvants, Immunologic↗
PubMed1995

Malignant mesothelioma of the pleura: interobserver variability.

AIMS: To assess the consistency of histopathological diagnosis of pleural malignant mesothelioma by estimating interobserver agreement between five pathologists. METHODS: Eighty eight histological sets pertaining to original diagnoses of pleural malignant mesothelioma were reviewed separately by each pathologist. Diagnostic likelihood was graded as definite (A), probable (B), possible (C), improbable (D), and definitely not (E) malignant mesothelioma. The following indexes were estimated: observed proportion of agreement (Po), kappa statistics and proportion of agreement for "positive" (Ppos) and "negative" (Pneg) diagnoses. RESULTS: Sixty cases (68.2%) were rated by at least three reviewers as A or B and by none of the others as D or E. Five (5.7%) were rated by at least two reviewers as D or E and by none of the others as A or B. Nine (10.2%) showed a serious disagreement, rated A or B and D or E. Agreement for sets obtained at necropsy/surgery (median kappa w = 0.57) was similar to that for endoscopic material (median kappa w = 0.54). Agreement was poor on material obtained by needle biopsy (median kappa w = 0.21). The median value of Ppos varied between 0.94 (necropsy/surgery) and 0.67 (needle biopsy) and that of Pneg between 0.78 (necropsy/surgery) and 0.34 (unspecified biopsy). Interobserver agreement on histological typing was good overall (median kappa = 0.59). CONCLUSIONS: Of the original histological diagnoses, 70% were consistently reproduced through panel review. Most indexes of agreement between pathologists ranged from poor (needle biopsy) to moderate (necropsy/surgery). Agreement in confirming malignant mesothelioma was greater than that regarding exclusion of this diagnosis. Of the cases finally considered to have malignant mesothelioma, the reproducibility of histological typing was relatively satisfactory.

Aged↗
PubMed1995

Late effects of intravesical bacillus Calmette-Guérin immunotherapy on bladder mucosa infiltrating lymphocytes: an immunohistochemical study.

During intravesical bacillus Calmette-Guérin (BCG) treatment for the prophylaxis of recurrent superficial bladder carcinoma, patients typically show a local inflammatory response involving mainly T lymphocytes, most of which have the helper-induced phenotype (CD4+) (CD4+/CD8+ ratio > 1). To evaluate whether this immunophenotypic profile of the lymphocytes persists also after the completion of this immunotherapy, we examined bladder biopsy specimens during the posttreatment follow-up period of 24 patients, previously submitted to a 2-year BCG administration. The intensity of inflammatory response differed among the patients and in 10 of them even between the scar and the normal mucosa of the bladder. A reversal to the pretreatment CD4+/CD8+ ratio < 1 occurred in the majority of subjects, including the 3 patients with histologically confirmed tumour recurrence. In addition, 11 tumour-free patients showed prevailing CD4+ cells in the scar mucosa and prevailing CD8+ in the normal mucosa of their bladder or vice versa. From these findings it appears that the long-term host response to BCG does not depend exclusively on an intense, long-lasting local mononuclear immune reaction.

Biopsy, Needle↗
PubMed1993

Giant cell fibroblastoma of the scrotum. A case report.

A case of giant cell fibroblastoma occurring in the scrotum of a 21-year-old male is described. It may have been a recurrence of a previous lesion in the same region, which was only clinically diagnosed as fibrolipoma when excised 10 years before. Giant cell fibroblastoma is a benign, locally recurrent tumor of youth and childhood which arises from superficial soft tissue. To our knowledge, only 2 other cases of scrotal involvement by this neoplasm have been reported.

Adult↗
PubMed1993

Cell proliferation in breast carcinoma assessed by a PCNA grading system and its relation to other prognostic variables.

This study was undertaken to relate the expression of the proliferating cell nuclear antigen (PCNA), a proliferation marker of putative prognostic significance, to some more established prognostic factors in a series of 60 consecutive breast cancer surgical specimens. PCNA was detected by the PC10 monoclonal antibody (MAb) using an immunohistochemical method and PCNA immunostaining was estimated on a semiquantitative basis, a cut-off value of 50% of positively stained tumour cells discriminating between the high (> 50%) and low (< 50%) PCNA grade. The PCNA grade did not correlate with tumour size and axillary node status. However, a high PCNA grade tended to be associated with a poor histological grade and there was an inverse relationship with oestrogen-receptor status, as determined by means of the immuno-histochemical staining for the oestrogen-induced pS2 protein. These conflicting results suggest that the possible prognostic usefulness of PCNA immunostaining, as a measure of cell proliferation rate, in breast cancer is yet to be demonstrated and can be validated only by direct relation to survival data.

Adenocarcinoma, Mucinous↗
PubMed1992

Cytologic diagnosis of malignant mesothelioma in serous effusions using an antimesothelial-cell antibody.

Differentiating mesothelioma, reactive mesothelium, and adenocarcinoma in serous effusions is often difficult, despite the application of ancillary techniques in support of the traditional cytomorphologic criteria. A polyclonal antimesothelial-cell antibody recently developed by our group was evaluated as a histogenetic marker on a series of primary (n = 12) and metastatic (n = 12) malignant effusions. Immunostaining was performed on paraffin sections from cell blocks. All mesothelioma effusions stained positive for the antibody, whereas, in contrast, all metastatic carcinoma specimens failed to react. These results (100 percent specificity and 100% sensitivity for mesothelioma) provide a basis for a reliable use of the antibody in the cytologic examination of suspicious or malignant serous effusions.

Adenocarcinoma↗
PubMed1992

Quantitative analysis of nucleoli and nucleolar organizer regions in cultured primary human normal, reactive and malignant mesothelial cells.

The number and the size of silver-stained intranuclear granules, which correspond to the nucleolus and nucleolar organizer regions, have been determined by means of quantitative methods in cultured primary human mesothelial cells obtained from normal, reactive and malignant mesothelium. The mean values per nucleus of the number, the total area, the average area, and the relative area of the silver-stained granules and the mean nuclear area were determined for each of the three conditions. Normal, reactive and malignant mesothelial cells differed significantly in all the features. These findings at the optical level reflect the differing rate of the nucleolar biosynthetic activity related to the different biological properties of the three cell types, and the features can be useful morphometric descriptors in the diagnostic pathology of the mesothelium.

Ascitic Fluid↗
PubMed1992

Changes in nucleolar transcriptional activity in hepatitis B virus-associated chronic liver diseases. Preliminary results from a quantitative study of silver-stained nucleoli.

Modifications of gene expression may occur in hepatitis B virus (HBV)-related chronic liver diseases, possibly also involving ribosomal RNA (rRNA) genes contained in the nucleolus. Changes in the level of transcriptional activity of rRNA genes are reflected by variations in the number and/or size of the nucleoli. Therefore a quantitative analysis of the silver-stained nucleoli (AgNus) was performed in a small series of liver needle biopsies from patients with HBV+ chronic persistent hepatitis (CPH) (n = 3), HBV+ chronic active hepatitis (CAH) (n = 3) and HBV+ cirrhosis (CIR) (n = 3). In each case, 100 hepatocytes were selected. The number of the nucleoli (AgNuN), their total area (tAgNuA), the average area of each nucleolus (xAgNuA), the nuclear area (NA) and the percentage ratio of tAgNuA related to NA (rAgNuA) were determined for each hepatocyte nucleus. The pooled mean values of all the features were significantly different (p less than 0.001) among the case groups. The results point towards a remarkable increase of nucleolar activity in CAH in comparison with CPH, whereas an additional increment of this activity is associated with the progress from CAH to CIR.

Biopsy, Needle↗