Intracellular Ig Identification on Paraffin-embedded Solitary Plasmacytoid Proliferation: A Routine Method to Define the Biological Nature of Plasma Cells

The difficulty to recognize morphologically the biological nature of the exuberant plasma cell proliferations is known by every pathologist. Therefore, an immunohistochemical method has been applied to routine paraffin-embedded sections of biopsies from 26 patients suspected to bear a solitary plasmacytoma. The method has allowed to distinguish between monoclonal (likely to be neoplastic) and polyclonal cases (likely to be reactive).

Technical pitfalls potentially affecting diagnoses in immunohistochemistry

Result of the immunohistochemical reactions routinely used in diagnostic surgical pathology should be properly interpreted, since false results, related to technical and interpretative pitfalls may lead to incorrect diagnosis. The main sources of such pitfalls are reviewed, analytically described and related to different steps (fixation, tissue processing and embedding, decalcification, antigen retrieval) which may affect the accuracy of immunohistochemistry. In addition, the presence of endogenous enzyme activity, improper binding of avidin to endogenous biotin, incorrect use of antibodies, chromogen and detection systems, as well as incorrect interpretation may produce unreliable data. The high frequency and extension of such pitfalls make mandatory the use of internal and external controls and adoption of cross-validation programmes. The present study, supported by an extensive review of the related literature, is intended as a guideline leading to proper interpretation of immunohistochemical data, an essential component of the diagnostic process. Experience on the antigen retrieval procedures for different antigens is also presented.

Management of neuroendocrine differentiated breast carcinoma

In neuroendocrine differentiated breast cancer, the coexistence of both neuroendocrine and exocrine components may raise some uncertainty about the best clinical approach to adopt. We describe the case of a patient with neuroendocrine differentiated breast carcinoma with lung metastases, who experienced a partial response after epirubicin chemotherapy. During subsequent maintenance hormone therapy with letrozole, plasma chromogranin A was consistently elevated even though CT showed disease stabilization. The patient was scheduled for surgery and radical resection was performed. She is still alive and disease free after over 37 months. Anthracyclines are effective in the treatment of neuroendocrine differentiated breast carcinoma. Surgical resection of metastatic lesions can lead to a durable disease-free status. Serial evaluation of circulating chromogranin A is useful in the follow-up of these patients.

Epidermal growth factor receptor overexpression correlates with a poor prognosis in completely resected non-small-cell lung cancer

BACKGROUND

We designed a prospective study to test epidermal growth factor receptor (EGFR) expression by immunohistochemistry (IHC) in resected stage I-IIIA non-small-cell lung cancer (NSCLC) and to correlate overexpression with survival.

PATIENTS AND METHODS

EGFR expression was evaluated in 130 consecutive NSCLC patients after radical surgery (60 squamous cell carcinomas, 48 adenocarcinomas, 22 large cell carcinomas: stage I, 41 (31%); stage II, 37 (29%) and stage IIIA, 52 (40%).

RESULTS

Overall, 101 of 130 (78%) specimens expressed EGFR, and with a cut-off value of 10% positive cells 48 cases (37%) were classified as positive. At univariate analysis, EGFR was significantly more expressed in stage III (50%) than stage I (20%) and stage II (25%) (P <0.03). No correlation with histotype was found. After a median follow-up of 84 months, both median survival time (18 versus 50 months), 2-year (43% versus 70%) and 5-year (31% versus 46%) survival rates of positive cases were significantly lower than negative ones [P <0.001; hazard ratio 1.96; 95% confidence interval (CI) 1.16-3.30]. At the multivariate analysis, EGFR overexpression and stage emerged as independent factors for cancer-related mortality.

CONCLUSION

In patients with radically resected stage I-IIIA NSCLC, EGFR overexpression predicts shorter survival, thus representing a valuable prognostic factor.

Molecular Genetic Study of a Metastatic Oligodendroglioma

Extracranial spread of neuroectodermal tumors is an unusual event, most frequently expected from glioblastomas and medulloblastomas. Single cases of metastatic oligodendrogliomas have been described, but no genetic data are reported. Oligodendrogliomas are characterized by distinct genetic alterations, i.e. loss of heterozygosity (LOH) of 1p and 19q; therefore, molecular genetic analysis of metastatic cases is of considerable interest. It may be instrumental in defining the distant tumor as metastatic oligodendroglioma and give clues to the genetic events associated with the highly malignant transformation. We present the case of a patient with multiple bone metastases from a cerebral oligodendroglioma. Oligodendroglioma grade II was the diagnosis both at original and second operation, performed 7 and 1 years before the extracranial dissemination. The extraneural spread presented before the local intracranial recurrence. The patient received procarbazine, lomustine, vincristine chemotherapy and radiotherapy after the second surgery. The computed tomography-guided biopsy of the bone lesions revealed tumor cells positive for GFAP, S-100 and Leu-7 and negative for cytokeratin, LCA and EMA. The genetic analysis of DNA from the original tumor, the bone metastasis and the autoptic brain tumor showed LOH of 1p; heterozygous deletion of CDKN2A/p 16 was detected as additional alteration in the metastasis and in the intracranial tumor at autopsy. TP53, MDM2 and CDKN2A/p14ARF genes were unchanged. Repeated brain surgery and extended survival may have acted as promoter of extraneural dissemination. Loss of CDKN2A most probably played an important role in the malignant progression: its involvement in metastatic potential remains to be clarified. Our data confirm that malignant transformation of oliogodendrogliomas may be undetected by histology and underscore the importance of genetic analysis. Coincidentally with intensive anticancer therapy, chemotherapy included, employed in patients with oligodendroglioma and the ensuing long survival, the frequency of metastatic oliogodendrogliomas may increase.

Exacerbated inflammatory responses in transgenic mice expressing an inhibitor of apoptosis protein (OpIAP)

Members of the inhibitor of apoptosis protein family are involved not only in suppressing apoptosis, but also in signal transduction, cell division, and are associated with some types of cancers. Here we show that transgenic expression of the inhibitor of apoptosis protein OpIAP in murine T lymphocytes leads to a significant increase in T-cell receptor-induced cell activation, proliferation and cytokine production. Transgenic T lymphocytes expressing OpIAP have a lower proliferation threshold in response to T-cell receptor stimulation. Unstimulated OpIAP transgenic T lymphocytes show elevated nuclear levels of NF-kappaB transcription factor that increase after in vivo antigen peptide treatment. OpIAP transgenic animals present an exacerbated inflammatory response in an experimental contact hypersensitivity model, suggesting increased T-cell activation in vivo. These data indicate a new role for the inhibitor of apoptosis proteins in T-lymphocyte activation and proliferation.

Relationship between neuroendocrine features and prognostic parameters in human prostate adenocarcinoma

PURPOSE

The biological behaviour of prostate cancer is highly variable and prediction by the commonly employed prognostic parameters is not sufficient. The concept of neuroendocrine (NE) differentiation in prostate adenocarcinoma has recently received increasing attention due to possible implications for prognosis and therapy.

MATERIALS AND METHODS

Core needle biopsies from 142 newly diagnosed patients were immunohistochemically examined for the coexistence of NE differentiation using an antibody against chromogranin A (CgA). Circulating CgA was available in 106 of these patients.

RESULTS

NE differentiation was found in 64 (45.1%) tumors. Among them 29 (20.4%) had CgA positive cells scattered or focally distributed in less than 5% per mm3 of tumor tissues, 26 (18.3%) between 5% and 10% and 9 (6.4%) more than 10%, respectively. There was a significant correlation between the extent of NE features and either Gleason score (P < 0.01) or stage of disease. Circulating CgA but not PSA correlated with immunohistochemical CgA (P < 0.03) particularly in metastatic cases.

CONCLUSIONS

These data support the concept that NE differentiation in human prostate cancer has a negative prognostic significance. Circulating CgA levels reflect immunohistochemical findings.

Immunohistochemical MIB-1 and p27kip1 as Prognostic Factors in Pleural Mesothelioma

Malignant pleural mesothelioma (MPM) is a tumour that usually presents a short survival time from diagnosis, but in a small number of patients a longer survival time has been observed. We have studied a series of ten long-term and ten short-term survivors with MPM to assess whether the MIB-1 proliferation index and the p27kip1 expression correlated with survival. Our results show significant difference in MIB-1 and in p27kip1 expression between the group of short and longer survival patients. It suggests that the difference in tumour growth fractions may express different biological behaviour and therefore indicate important factors in MPM prognosis.

Opposing RA and FGF signals control proximodistal vertebrate limb development through regulation of Meis genes

Vertebrate limbs develop in a temporal proximodistal sequence, with proximal regions specified and generated earlier than distal ones. Whereas considerable information is available on the mechanisms promoting limb growth, those involved in determining the proximodistal identity of limb parts remain largely unknown. We show here that retinoic acid (RA) is an upstream activator of the proximal determinant genes Meis1 and Meis2. RA promotes proximalization of limb cells and endogenous RA signaling is required to maintain the proximal Meis domain in the limb. RA synthesis and signaling range, which initially span the entire lateral plate mesoderm, become restricted to proximal limb domains by the apical ectodermal ridge (AER) activity following limb initiation. We identify fibroblast growth factor (FGF) as the main molecule responsible for this AER activity and propose a model integrating the role of FGF in limb cell proliferation, with a specific function in promoting distalization through inhibition of RA production and signaling.

Ceramide-induced cell death is independent of the Fas/Fas ligand pathway and is prevented by Nur77 overexpression in A20 B cells

The role of ceramide in triggering apoptosis is still a matter of debate. While in some experimental systems, ceramide was shown to mediate Fas-induced cell death, in other instances it was claimed to induce the expression of Fas ligand (FasL), killing cells in a caspase-dependent fashion. We found that, in mature A20 B cells, ceramide-induced apoptosis is independent of the caspase pathway, since we observed no ICE-like, CPP32-like and Mch2 activities and no PARP proteolysis. Moreover, we were unable to protect these cells from ceramide-induced apoptosis using caspase inhibitors, while they blocked Fas-induced apoptosis and no FasL induction could be detected following ceramide treatment. These results suggest that ceramide does not induce apoptosis through the Fas/FasL pathway. We also found that overexpression of Nur77, a zinc-finger transcription factor described to upregulate FasL, antagonizes ceramide-induced apoptosis, but not Fas-induced apoptosis. This further supports the hypothesis that Fas and ceramide death pathways are independent in A20 cells. Ceramide-induced cell death was associated with increased c-myc, p53, Bax and p27kip1 levels; in contrast, cells transfected with Nur77 (A20Nur77), resistant to ceramide-induced apoptosis, showed a marked downregulation of p53 after ceramide treatment, with neither Bax nor p27kip1 induction. In conclusion, our results suggest that, in the A20 B cell line, Fas and ceramide trigger two distinct pathways and that Nur77 overexpression confers protection against ceramide-mediated apoptosis which correlates with inhibition of p53, Bax and p27kip1 induction.

Conserved regulation of proximodistal limb axis development by Meis1/Hth

Vertebrate limbs grow out from the flanks of embryos, with their main axis extending proximodistally from the trunk. Distinct limb domains, each with specific traits, are generated in a proximal-to-distal sequence during development. Diffusible factors expressed from signalling centres promote the outgrowth of limbs and specify their dorsoventral and anteroposterior axes. However, the molecular mechanism by which limb cells acquire their proximodistal (P-D) identity is unknown. Here we describe the role of the homeobox genes Meis1/2 and Pbx1 in the development of mouse, chicken and Drosophila limbs. We find that Meis1/2 expression is restricted to a proximal domain, coincident with the previously reported domain in which Pbx1 is localized to the nucleus, and resembling the distribution of the Drosophila homologues homothorax (hth) and extradenticle (exd); that Meis1 regulates Pbx1 activity by promoting nuclear import of the Pbx1 protein; and that ectopic expression of Meis1 in chicken and hth in Drosophila disrupts distal limb development and induces distal-to-proximal transformations. We suggest that restriction of Meis1/Hth to proximal regions of the vertebrate and insect limb is essential to specify cell fates and differentiation patterns along the P-D axis of the limb.

DIO-1 is a gene involved in onset of apoptosis in vitro, whose misexpression disrupts limb development

The DIO-1 (death inducer-obliterator-1) gene, identified by differential display PCR in pre-B WOL-1 cells undergoing apoptosis, encodes a putative transcription factor whose protein has two Zn finger motifs, nuclear localization signals, and transcriptional activation domains, expressed in the limb interdigitating webs during development. When overexpressed, DIO-1 translocates to the nucleus and activates apoptosis in vitro. Nuclear translocation as well as induction of apoptosis are lost after deletion of the nuclear localization sequences. DIO-1 apoptotic induction is prevented by caspase inhibitors and Bcl-2 overexpression. The in vivo role of DIO-1 was studied by misexpressing DIO-1 during chicken limb development. The most frequently observed phenotype was an arrest in limb outgrowth, an effect that correlates with the inhibition of mesodermal and ectodermal genes involved in this process. Our data demonstrate the ability of DIO-1 to trigger apoptotic processes in vitro and suggest a role for this gene in cell death during development.

Different immunohistochemical patterns of TGF-beta1 expression in benign and malignant adrenocortical tumours

OBJECTIVE

Transforming growth-factor beta1 (TGF-beta1) influences a number of specific functions of adrenocortical cells in several animal species. The aim of our study was to evaluate by immunohistochemical analysis the presence and distribution of TGF-beta1 in normal adrenal tissue and in different adrenal tumours.

PATIENTS

We analysed 8 functioning (5 adenomas and 3 carcinomas) and 15 non functioning (6 adenomas and 9 carcinomas) adrenal tumours and 6 normal adrenal glands.

RESULTS

In normal adrenal glands, the glomerulosa and the reticularis zones displayed diffuse cytoplasmic staining, while the fasciculata zone was almost completely negative. Functioning adenomas displayed cytoplasmic staining restricted to compact cells while in nonfunctioning adenomas, prevalently composed by clear cells, no staining was observed. Overall, adrenal carcinomas were characterized by the lack of cytoplasmic positivity and by sporadic positive cells around vessels both in functioning and in nonfunctioning tumours.

CONCLUSIONS

TGF-beta1 expression is associated with active steroid secretion in normal adrenal tissue, as well as in benign cortical adenomas, while this relationship is lost in primary adrenal malignancies. These data provide indirect evidence for a regulatory role played by TGF-beta1 on steroid secretory pathways.

Blocked negative selection of developing T cells in mice expressing the baculovirus p35 caspase inhibitor

Clonal deletion in the thymus by apoptosis is involved in purging the immune system of self-reactive T lymphocytes (negative selection). Cysteine proteases (caspases) belonging to the CPP32 family are activated during this process. We have produced transgenic mice expressing baculovirus p35, a broad-range caspase inhibitor. Thymocytes from p35 transgenic mice were resistant in vitro to several apoptosis-inducing agents; this resistance correlated with the inhibition of CPP32-like activity. Negative selection in vivo of thymocytes triggered by two exogenous antigens, staphylococcal enterotoxin B superantigen and an antigenic peptide in the F5 T-cell receptor transgenic model, was specifically inhibited in p35 transgenic mice. Our results provide direct evidence for caspase involvement in negative selection during thymocyte development.

Identification and characterization of a new oncogene derived from the regulatory subunit of phosphoinositide 3-kinase

p85/p110 phosphoinositide 3-kinase (PI3K) is a heterodimer composed of a p85-regulatory and a p110-catalytic subunit, which is involved in a variety of cellular responses including cytoskeletal organization, cell survival and proliferation. We describe here the cloning and characterization of p65-PI3K, a mutant of the regulatory subunit of PI3K, which includes the initial 571 residues of the wild type p85alpha-protein linked to a region conserved in the eph tyrosine kinase receptor family. We demonstrate that this mutation, obtained from a transformed cell, unlike previously engineered mutations of the regulatory subunit, induces the constitutive activation of PI3K and contributes to cellular transformation. This report links the PI3K enzyme to mammalian tumor development for the first time.

Lck is necessary and sufficient for Fas-ligand expression and apoptotic cell death in mature cycling T cells

Apoptotic cell death is induced in mature cycling T cells upon ligation of the Ag-specific TCR. This process is essential for the maintenance of homeostasis in the immune system, as it is capable of down-regulating ongoing immune responses. The analysis of the mechanism underlying TCR-induced programmed cell death has focused the attention of many scientists recently. In this regard, several recent reports have implicated Fas/Fas-ligand molecules as the final mediators of this process. Several other gene products have been implicated in the control of apoptosis (as Bcl-2, p53, and c-Myc); however, no information was available in the early signaling molecules that trigger this phenomena. The results presented in this work indicate that pp56(lck) src family kinase is actually required for the TCR to trigger cell death in mature cycling T cells. In fact, while inhibition of pp56(lck) expression with antisense oligonucleotides blocked TCR-induced apoptosis, pharmacologic inhibition of phosphatidylinositol 3-kinase activity had no effect. Accordingly, ligation of the Ag receptor in a cell line defective for pp56(lck) expression was unable to induce apoptosis, although it induced cellular stimulation, as measured by the expression of CD69. In addition, we show in this work that expression of constitutively active pp56(lck) mutants, but not pp59(fyn) mutants, in the absence of any other TCR-derived signal, is sufficient to induce apoptosis not only in transformed, but also in normal cycling T cells. Finally, evidence is presented indicating that a mechanism through which pp56(lck) regulates TCR-induced apoptosis in mature cycling T cells is by controlling Fas-ligand expression.

Lck is necessary and sufficient for Fas-ligand expression and apoptotic cell death in mature cycling T cells

Apoptotic cell death is induced in mature cycling T cells upon ligation of the Ag-specific TCR. This process is essential for the maintenance of homeostasis in the immune system, as it is capable of down-regulating ongoing immune responses. The analysis of the mechanism underlying TCR-induced programmed cell death has focused the attention of many scientists recently. In this regard, several recent reports have implicated Fas/Fas-ligand molecules as the final mediators of this process. Several other gene products have been implicated in the control of apoptosis (as Bcl-2, p53, and c-Myc); however, no information was available in the early signaling molecules that trigger this phenomena. The results presented in this work indicate that pp56(lck) src family kinase is actually required for the TCR to trigger cell death in mature cycling T cells. In fact, while inhibition of pp56(lck) expression with antisense oligonucleotides blocked TCR-induced apoptosis, pharmacologic inhibition of phosphatidylinositol 3-kinase activity had no effect. Accordingly, ligation of the Ag receptor in a cell line defective for pp56(lck) expression was unable to induce apoptosis, although it induced cellular stimulation, as measured by the expression of CD69. In addition, we show in this work that expression of constitutively active pp56(lck) mutants, but not pp59(fyn) mutants, in the absence of any other TCR-derived signal, is sufficient to induce apoptosis not only in transformed, but also in normal cycling T cells. Finally, evidence is presented indicating that a mechanism through which pp56(lck) regulates TCR-induced apoptosis in mature cycling T cells is by controlling Fas-ligand expression.

Linomide administration to mice attenuates the induction of nitric oxide synthase elicited by lipopolysaccharide-activated macrophages and prevents nephritis in MRL/Mp-lpr/lpr mice

Nitric oxide is involved as a messenger molecule in a large number of physiologic and pathologic responses. Local generation of high nitric oxide output through the expression of the calcium-independent, cytokine-inducible form of nitric oxide synthase (iNOS) can result in either protective or damaging effects. The development of drugs that specifically suppress iNOS expression or inhibit its activity may therefore provide an excellent therapeutic tool for treatment of a diverse set of dysfunctions, including asthma, inflammatory processes, and autoimmune disease. We show compelling evidence that linomide, an immunomodulator known to ameliorate autoimmune diseases, prevents accumulation in the macrophages of mRNA encoding iNOS in mice injected with LPS. This effect is partially mediated by the blocking of TNF-alpha and IL-beta production by activated macrophages. Here, we also present evidence that kidneys from MRL/Mp-lpr/lpr mice express high iNOS levels when the mice develop glomerulonephritis. The administration of linomide to MRL/Mp-lpr/lpr mice significantly decreases iNOS mRNA levels and prevents the development of glomerulonephritis, extending the half-life of mice of this strain. This linomide effect is compatible with its role in preventing the development of autoimmune disease and extends its possible use to other pathologic manifestations associated with iNOS expression, such as the systemic lupus erythematosus-associated glomerulonephritis present in MRL/Mp-lpr/lpr mice.

Linomide administration to mice attenuates the induction of nitric oxide synthase elicited by lipopolysaccharide-activated macrophages and prevents nephritis in MRL/Mp-lpr/lpr mice

Nitric oxide is involved as a messenger molecule in a large number of physiologic and pathologic responses. Local generation of high nitric oxide output through the expression of the calcium-independent, cytokine-inducible form of nitric oxide synthase (iNOS) can result in either protective or damaging effects. The development of drugs that specifically suppress iNOS expression or inhibit its activity may therefore provide an excellent therapeutic tool for treatment of a diverse set of dysfunctions, including asthma, inflammatory processes, and autoimmune disease. We show compelling evidence that linomide, an immunomodulator known to ameliorate autoimmune diseases, prevents accumulation in the macrophages of mRNA encoding iNOS in mice injected with LPS. This effect is partially mediated by the blocking of TNF-alpha and IL-beta production by activated macrophages. Here, we also present evidence that kidneys from MRL/Mp-lpr/lpr mice express high iNOS levels when the mice develop glomerulonephritis. The administration of linomide to MRL/Mp-lpr/lpr mice significantly decreases iNOS mRNA levels and prevents the development of glomerulonephritis, extending the half-life of mice of this strain. This linomide effect is compatible with its role in preventing the development of autoimmune disease and extends its possible use to other pathologic manifestations associated with iNOS expression, such as the systemic lupus erythematosus-associated glomerulonephritis present in MRL/Mp-lpr/lpr mice.

p53 protein expression as prognostic factor in patients undergoing radical prostatectomy for prostatic cancer

The authors give preliminary data on the evaluation of the p53 protein expression as prognostic factor in patients subjected to radical prostatectomy for prostatic cancer. p53 protein immunohistochemical nuclear staining was carried out on neoplastic tissue obtained from systematic sextant prostatic biopsies at the time of diagnosis. Out of 46 Patients 15 (32%) were p53 positive (p53+). No statistical correlation was observed between P53 staining, preoperative PSA and pathological Gleason Score, while the rate of patients with nodal involvement (pN+) was higher in the p53+ group than the P53- group with low statistical significance (p<0.03). The authors cannot yet evaluate Progression time and survival because the mean follow-up of the patients is still too short (30 months). The study is still in progress.

Evaluation of c-ras oncogene product (p21) in superficial bladder cancer

OBJECTIVES

The aim of our study is the evaluation of the prognostic importance of p21 protein in superficial bladder cancer.

METHODS

One hundred and fourteen patients with an initial diagnosis of monofocal bladder cancer (stage Ta-T1) following TUR were investigated. On the tissue removed by TUR, besides the usual pathological evaluation, an immuno-histochemical investigation was carried out in order to ascertain the presence of c-ras oncogene product (protein p21). The actuarial curves concerning the time free from the first recurrence were computed, comparing different subgroups in regard to protein p21 presence, grade and stage of the tumour.

RESULTS

The analysis of the results shows the importance of tumour stage as a predictor of recurrence, as well as that of the presence of c-ras products. This last factor increases the risk of recurrence almost 2-fold, in the same time lag, for c-ras-positive patients (p < 0.001). The prognostic significance of c-ras is independent of stage.

CONCLUSION

Our data underline the possibility of acquiring important information on the prognosis of superficial bladder cancer patients, pointing out the significance of c-ras oncogene product.

Distribution of Kaposi's sarcoma herpesvirus sequences among lymphoid malignancies in Italy and Spain

In this study we have tested the distribution of Kaposi's sarcoma herpesvirus (KSHV) DNA sequences throughout the spectrum of lymphoid neoplasia in Italy and Spain. 180 cases of lymphoid malignancies representative of the major histologic and immunophenotypic categories of B- and T-cell tumours were analysed by means of a polymerase chain reaction-based assay. KSHV sequences were consistently absent in all categories of lymphoid malignancies studied, with the exception of a subset of B-cell non-Hodgkin's lymphomas localizing in the pleural, pericardial or peritoneal cavities, and fulfilling the diagnostic criteria of body-cavity-based lymphoma. The selective and consistent association of KSHV sequences with cases of body-cavity-based lymphoma throughout the spectrum of lymphoid neoplasms suggests that KSHV may be involved in the pathogenesis of this peculiar type of lymphoid malignancy.

High frequency of p53 expression in colo-rectal adenomatous polyps

Previous studies on p53 protein expression in colonic adenomas showed controversial results. The present study evaluates the p53 expression in colonic adenomas, at different dysplasia degrees, by immunohistochemical analysis, using a newly introduced monoclonal anti-p53 antibody. Paraffin embedded sections of 48 colorectal adenomas, 5 colonic carcinomas and 11 normal colonic biopsies were studied by immunohistochemical analysis using a monoclonal mouse anti-p53 antibody (clone DO-1). Normal colonic mucosa specimens and 5/48 adenomas were found negative for p53 staining. p53-positive nuclei were less than 10% in 22/48 and between 10 and 40% in 15/48 adenomas. In 6/48 adenomas and in 4/5 carcinomas we found a high percentage of p53-positive nuclei (> 40%). Immunohistochemical p53-positivity is a common event in colonic adenomas, not dependent on dysplasia degree. It might be the result of p53 wild-type increase, due to the typical genomic instability of colonic adenomas.

Oncogeni ed integrine nel carcinoma prostatico: Oncogenes and integrine in prostate cancer

We studied the c-ras oncogene and p53 oncosuppressorgene products (p21, p53) and also some integrine in prostatic cancer and BPH patients to evaluate a possible prognostic value. p21 was detected only in cancer tissue without any significant difference between different stages and grades of prostatic disease. p53 was more expressed in prostatic cancer than BPH, without any statistical difference. No correlation between p53 expression and different stages and grades was demonstrated. Fibronectin receptor (integrin) was significantly higher in cancer than BPH (P < 0,05). p53 expression, only in stage D patients, was related to a significant shorter progression time (P < 0,0001). Fibronectin receptor correlated with a significantly higher progression risk (Odds Ratio = 2,5).

Immunohistochemical evaluation of P-glycoprotein in human malignancies by monoclonal antibody MC57

P-glycoprotein expression was analyzed on 137 formalin-fixed, paraffin-embedded human tumours by monoclonal antibody (MAb) MC57. This MAb recognizes an extracellular human specific P-glycoprotein epitope and defines their multidrug resistance (MDR) phenotype by its binding on cells. Immunohistochemistry indicated that this MAb reacted in human cells and tissues in the same pattern as that found with other MAbs to P-glycoprotein. However, the present extensive study demonstrated that MAb MC57 is a highly specific reagent for the evaluation of an extracellular P-glycoprotein epitope preserved after fixation procedures and that this MAb is available to assess P-glycoprotein expression in routinely processed human tumour specimens.

Rebound thymic hyperplasia following high dose chemotherapy and allogeneic BMT

We describe a child with acute lymphoblastic leukemia who showed mediastinal widening 8 months after allogeneic BMT. Total thymectomy was carried out by the transcervical approach. Histologic examination showed only thymic hyperplasia. The immunohistologic investigation revealed a normal distribution of thymic cell elements, without evidence of clonal proliferation of lymphocytic subpopulations. This case supports the hypothesis that thymic hyperplasia following chemotherapy may be merely a rebound phenomenon. The patient had an uneventful postoperative recovery and remains in remission more than 1 year after BMT.

Prognostic significance of Ki67 labelling in resected non small cell lung cancer

One hundred and eleven tissue samples of primary non small cell lung cancer obtained from patients undergoing radical surgery for resectable disease were investigated for the presence and distribution of Ki67 related antigen using an immunohistochemical technique, as a marker of the proliferative activity of the tumour. No correlation was seen between Ki67 expression and clinico-pathological variables (sex, age, histology, grading and pTNM stage) but disease-free survival was significantly lower in patients with higher Ki67 score (> 25% positive cells) at diagnosis (P < 0.03). Growth fraction evaluated by Ki67 labelling may provide a complementary prognostic parameter in non small cell lung cancer.

Putative prethymic T cell precursors within the early human embryonic liver: a molecular and functional analysis

Hematopoietic cells present in the liver in early human fetal life were characterized by phenotypic analysis using a broad panel of monoclonal antibodies. Expression of very late antigen 4 and leukocyte function-associated antigen 3 cell adhesion receptors and 4F2 cell activation molecules was found in all fetal liver hematopoietic cells before acquisition of T cell-, B cell-, or myeloid-specific surface markers, and before the time of intrathymic colonization. Molecular studies showed that expression of the interleukin 2 receptor beta (IL-2R beta) also occurred in the embryonic liver at this early ontogenic stage. In contrast, no expression of IL-2R alpha or IL-2 transcripts was found in fetal liver cells, whereas transcription of the IL-4 gene was detected in a small fetal liver cell subset. Putative T cell precursors were identified among the hematopoietic fetal liver cells by the expression of genes encoding the gamma, delta, epsilon, and zeta invariant chains of the CD3-T cell receptor (TCR) complex. However, no transcription of the polymorphic alpha and beta TCR genes was detected. Functional in vitro assays further demonstrated that fetal liver hematopoietic cells from those early embryos were capable of proliferating in response to T cell growth factors, including IL-4 and IL-2. However, whereas IL-4-induced proliferation paralleled the appearance in vitro of CD45+CD7-CD4dull cells expressing the CD14 myeloid antigen, as well as of CD34+ primitive hematopoietic progenitors, differentiation into CD45+CD7+CD8+CD3- immature T cells was observed when using IL-2. Moreover, coculture with thymic epithelial cell monolayers provided additional evidence that early fetal liver hematopoietic cells may include very primitive T cell precursors, which were able to differentiate in vitro into TCR alpha/beta+ mature T cells. Therefore, our results indicate that, after triggering of the T cell-specific maturation program in primitive fetal liver hematopoietic progenitors, specific signals provided intrathymically by epithelial cells may fulfill the requirements to drive terminal differentiation of prethymically committed T cell precursors.

Monoclonal antibody Ki-67 in the study of the proliferative activity of bladder carcinoma

We studied the proliferative activity of bladder carcinoma using monoclonal antibody Ki-67, which is able to stain a nuclear antigen exclusively present in cells in the cell cycle, that is with activated deoxyribonucleic acid (DNA). We used this immunohistochemical technique on neoplastic tissue removed by transurethral resection from 101 patients. A significant correlation was observed (p less than 0.003) between cells with activated DNA and histological grading, even though within the context of each grade we observed tumors with a different proliferation index. Furthermore, we studied the location of the activated cells in the context of the tumor. In invasive tumors (stages T1 to T4) cells with activated DNA were always present at the base of implant of the tumor and in the neoplastic tissue that infiltrates the bladder wall. In regard to noninvasive tumors (stage Ta), in 57% of the cases most cells with activated DNA were present in the vegetative portion of the tumor and there were no recurrences at followup, while in 43% of the cases such cells were present also or especially at the base of implant of the tumor, near the lamina propria. In the latter patients we observed a 94% recurrence rate. These results suggest that the immunohistochemical assessment of the proliferative activity of transitional tumors of the bladder, using monoclonal antibody Ki-67, and the evaluation of the location of stained neoplastic cells provide a more reliable estimate of biological aggressiveness than that obtained with histopathological patterns alone.

Attenuation of autoimmune disease and lymphocyte accumulation in MRL/lpr mice by treatment with anti-V beta 8 antibodies

MRL-MP-lpr/lpr mice are afflicted by a severe systemic autoimmune disease that is aggravated by the lpr mutation resulting in the accumulation of phenotypically abnormal lpr cells (CD3+CD4-CD8-) in all lymphoid issues including hyperplastic lymph nodes. Given that products of the T cell receptor V beta 8 gene family are overrepresented among lpr cells, different schedules aimed at selectively decreasing the frequency of lpr cells were designed. First, continuous administration of the monoclonal antibody F23.1 (specific for V beta 8 products) resulted in a significant depletion of V beta 8+ cells and prevented the manifestation of lymph accumulation at the same time as it reduced the serological, clinical, and histopathological signs of autoimmune disease. Along the same line, administration of either F23.1 or two different anti-F23.1 anti-idiotypic antibodies to MRL/Mp-lpr/lpr mothers elicited, in the offspring, the production of antibodies sharing a recurrent idiotype with F23.1 and resulted in long-term amelioration of autoimmunity and lymphadenopathy. Thus, a strategy aimed at specifically reducing the frequency of a subset of lpr cells proved successful in mitigating the autoimmune process.

Detection of multidrug resistance associated P-170 glycoprotein in previously untreated non small cell lung cancer

Samples of Non Small Cell Lung Cancer (NSCLC) and normal bronchial tissue obtained in patients submitted to radical surgery and without previous exposure to cytotoxic drugs were investigated for the expression of P-170 glycoprotein using C-219 monoclonal antibody and an immunohistochemistry technique. In normal bronchial tissue the immunostaining was confined to the lumenal surface of the epithelium. Fifteen out of 86 NSCLC had more than 1/4 of examined cells positive for P-170 glycoprotein, but the heterogeneity of the expression ranged from rare scattered cells to a positive pattern for nearly all cells considered, without any relationship with pathologic and clinical prognostic variables.

[Alveolar macrophage subpopulations and circulating monocytes. Immunophenotypic study in healthy non-smokers]

Peripheral blood monocytes of 10 non-smoker normal subjects and the macrophages of their bronchoalveolar lavage fluid (BAL) were investigated with two commercially available monoclonal antibodies (MAC 387, CD14). Surface membrane monocyte cells show simultaneously both markers. Instead alveolar macrophage (MA) can be divided in three different phenotype groups by the expression of the two markers (MAC 387+/CD14-, MAC 387+/CD14+, MAC 387-/CD14+). Particularly, MA with MAC 387+/CD14+ phenotype are adherent cells and morphologically lack anthracosis. Their alveolar presence in non-smokers can be due to normal turnover of monocytes from blood into alveoli. By contrast MA with MAC 387+/CD14- phenotype are non-adherent cells without anthracosis. At last MA with MAC 387-/CD14+ phenotype are non-adherent cells but different amounts of anthracosis in their cytoplasm can be observed.

The thousand and one ways of being a T cell

Developing T cells diverge to several different effector classes, identified by their ability to express different set of genes. Aside from the genes encoding components of the TCR/CD3, there are many others that are activated and/or inactivated during T-cell development, but the functions of most of them are not yet defined. Despite the significant progress made, several fundamental aspects of the major steps of T-cell differentiation remains unclear. Thus, while long ago it was realized that the thymus is a central organ for the development of functionally competent T lymphocytes, it appears clear today that ectopic T-cell differentiation can also take place. In this article we review some of the molecules implicated in T-cell development and discuss some of the pathways that lead to mature T cells from precursors, both intra- and extra-thymically, as well as their implications in the acquisition of self tolerance.

Analysis and characterization of the interleukin 2 receptor alpha and beta chain expression in CD4-CD8- cells

The differential effects that the binding of interleukin 2 (IL-2) to its beta or alpha beta receptors might induce in two different CD4-CD8- T-cell lines were analysed. While LD1.T3b, a double-negative T cell derived from MRL/lpr mice, constitutively expressed high levels of the IL-2R beta chain, YAC-1, a Moloney sarcoma virus-transformed CD4-CD8- T cell, expressed (as an activated T cell) the beta and alpha chains. The presence of IL-2 in the culture medium was lethal for LD1.T3b cells, while it had no effect on the growth of YAC-1 cells. IL-2 increased the expression of the beta chain and, to a lesser extent, of the alpha chain in YAC-1 cells. In addition, other markers such as CD4 and CD5 were induced by IL-2 in this cell line.

Identity of PB76 differentiation antigen and lymphocyte alkaline phosphatase

Alkaline phosphatases (APases, EC 3.1.3.1) are ecto-enzymes bound to cell membranes by a phosphatidyl-inositol anchor. We have previously shown that APase is present on activated murine B cells and its expression correlates with the process of B cell differentiation into immunoglobulin secretion. Recently, a monoclonal antibody (mAb), G-5-2, that recognizes a 76-kDa molecule preferentially expressed on the surface of pre-B and plasma cells (PB76) was described. Some features shared by APase and PB76 differentiation antigen suggest that the G-5-2 mAb might be specific for lymphocyte APase. Here, we have analyzed this possibility and found an absolute correlation between PB76 expression in cells and their APase activity. Although PB76 has been described as a B cell-restricted marker, PB76 is also expressed on some T cells, such as the YAC-1 T cell lymphoma, that are known to bear APase. Treatment of YAC-1 cells with phosphatidylinositol-specific phospholipase C resulted in a quantitatively correlated removal of both APase and PB76 antigens. Moreover, we demonstrate that PB76 antigen has APase activity using an enzyme-antigen immunoassay with the G-5-2 mAb. We conclude that PB76 and lymphocyte APase are one and the same antigen.

[Autoimmune aspects of a case of chronic interstitial cystitis]

Chronic interstitial cystitis is a disease characterized by clinical recurring cystitis with histopathological aspects of a chronic aspecific inflammation of the bladder. Etiopathogenesis is still unknown, even if autoimmunity has been hypothesized in some cases. In this paper we report an immunopathologic and immunohistochemical study on a case of chronic interstitial cystitis. The inappropriate immunologic behaviour of the lymphocyte populations, the inhibition of leukocytes migration with bladder extracts and the immunofluorescent findings of IgG and C3 deposits in the mucosa support the hypothesis of an autoimmune pathogenesis of the disease.

[Neuron-specific enolase in bronchial carcinoma. Immunohistochemical and immunoenzyme study]

Serum level of neuro-specific enolase (NSE) was determined in 20 lung cancer patients. NSE concentration was detected also on neoplastic tissue and NSE-positive neoplastic cells on histological sections were observed immunohistochemically. The presence of high level of NSE was showed in small cell lung cancer.

[Distribution and prognostic value of CEA and TPA in cancer of the lung]

Serum levels of carcinoembryonic antigen (CEA) and tissue polypeptide antigen (TPA) were investigated in 53 lung cancer patients. The higher percentage of patients with serum CEA positivity was observed within the anaplastic lung cancer group. TPA serum positivity was found in similar percentage in all the examined groups. Relationship between serum CEA positivity and/or serum TPA positivity and survival were then carried out.

[Prognostic value of serum and tissue CEA evaluation in lung cancer]

Serum concentration of carcinoembryonic antigen (CEA) was determined in 53 lung cancer patients before and 1 month after surgery. Relationships between serum CEA levels after and before surgery and survival were carried out. Furthermore, histological sections of the neoplastic surgical material were stained with anti human CEA antibody using an immunohistochemical method. The positivity of the neoplastic cells and of the macrophages were then analyzed and discussed.

[Prognostic significance of plasmatic concentration of fibronectin in patients with bronchial carcinoma]

Plasma levels of fibronectin were determined in 50 lung cancer patients and in 25 normal subjects. Immunoturbidimetric assay was performed to detect possible variations of plasma fibronectin concentration in neoplastic patients. Moreover plasma levels of fibronectin were related to clinical stage, histological type of tumor and survival after surgery.

[Immuno-oncologic monitoring of patients with bronchial carcinoma. IV. Aspects of the immunocompetence system]

Some aspects of the immunocompetent system are tested in 84 lung cancer patients at time of diagnosis and during the natural course of the disease. Results show no significant variations for many immunological tests during the course of the neoplasia. Significant alterations are observed in T-lymphocyte and macrophage evaluation. Moreover, some immunological data are related to lung cancer post-surgical survival.

[Immuno-oncologic monitoring of patients with bronchial carcinoma. III. Plasma glycoproteins]

Alpha and beta serum glycoprotein levels were determined in lung cancer patients at time of diagnosis and during the natural course of the disease. The results do not suggest that these glycoproteins can be used as tumour markers. Moreover, some glycoproteins, which have activity in cell-mediated processes and macrophage functions, can suggest prognosis.