Biomedical subjects

M Piccioli

Publications and source records attributed to M Piccioli.

At least 37 records · Page 2Linked to original sources

PubMed2000

The pathologist's view point. Part II --aggressive lymphomas.

BACKGROUND AND OBJECTIVES: The REAL/WHO classification constitutes a new tool for the better understanding and treatment of malignant lymphomas. The authors focus on the key features of aggressive B- and T-cell lymphomas, aiming to contribute to the cross-talk between pathologists and clinicians. DATA SOURCES AND METHODS: Each lymphoma entity is analyzed on the basis of the most representative contributions in the literature and the authors' experience gained in studying more than 20,000 lymphoid tumors over a 20-year period. RESULTS: Guidelines for diagnosis and areas of interest for future clinico-pathologic studies are identified and discussed. Within this context, selected data obtained by the application of novel markers are presented. INTERPRETATION AND CONCLUSIONS: The present know- ledge and organization of malignant lymphomas now make the development of tailored therapies a feasible goal.

Humans↗

PubMed1999

Structural and dynamical properties of a partially unfolded Fe4S4 protein: role of the cofactor in protein folding.

Heteronuclear multidimensional NMR spectroscopy was used to investigate in detail the structural and dynamical properties of a partially unfolded intermediate of the reduced high-potential iron-sulfur protein (HiPIP) from Chromatium vinosum present in 4 M guanidinium chloride solution. After an extensive assignment of 15N and 1H resonances, NOE data, proton longitudinal relaxation times, and 3JHNHalpha coupling constants as well as 15N relaxation parameters (T1, T2, T1rho, and 1H-15N NOE) were obtained and used to build a structural model of the intermediate. The Fe4S4 cluster of the HiPIP plays a decisive role in determining the resulting structure, which is random in the N-terminal half of the protein and partially organized in the loops between the cysteines bound to the cluster. Consistent with the structural data, the backbone mobility is typical of folded proteins in the regions where there are elements of structure and increases with the structural indetermination.

Iron-Sulfur Proteins↗

PubMed1999

T-cell prolymphocytic leukaemia: does the expression of CD8+ phenotype justify the identification of a new subtype? Description of two cases and review of the literature.

T-cell chronic lymphocytic leukaemia (T-CLL) has recently been reclassified under the heading of T-cell prolymphocytic leukaemia (T-PLL) because of its unfavourable clinical course, independently of the morphologic features. This rare neoplasm usually shows CD4+/CD8- phenotype. Herein we report on two cases of T-PLL with CD8 expression that correspond to a possible variant of the disease first proposed by Hui et al. in 1987. These cases presented with malignant cells showing immunophenotypic features that can be easily identified and distinguished from other peripheral T-cell leukemias. However, the total number of cases studied is inadequate for defining a discrete clinico-pathologic entity with characteristic clinical features and cytogenetical abnormalities. An international collaboration in which tissue from similar cases is referred to a central pathologist for immunophenotyping and cytogenetical study, and clinical data are centrally compiled, may assist in defining this rare malady as a discrete clinico-pathologic entity.

Adult↗

PubMed1999

Beta-HCG aberrant expression in primary mediastinal large B-cell lymphoma.

We report on a primary mediastinal large B-cell lymphoma with aberrant expression of beta-human chorionic gonadotropin (beta-hCG). The patient, a 33-year-old man, had cough, dyspnea, fever, superior vena cava syndrome, and a mediastinal bulky tumor. A biopsy showed that the latter was characterized by large cells, sclerosis, and compartmentalization. The neoplastic elements expressed CD45, CD20, CD79a and, partially, CD30, whereas they were negative for CD3, epithelial membrane antigen and cytokeratins. Surprisingly, they displayed a clear-cut positivity for beta-hCG. The remaining oncofetal markers applied (PLAP and alpha1-fetoprotein) were negative. Electron microscopy demonstrated the presence of numerous nuclear pockets and the lack of intercellular junctions. DNA analysis by polymerase chain reaction showed clonal rearrangement of Ig heavy-chain genes. The patient responded promptly to the administration of MACOP-B. To the best of our knowledge, this is the first example of B-cell lymphoma showing positivity for beta-hCG; a similar aberrant expression was previously observed only in three Japanese patients with human T-cell lymphotropic virus type I+ adult T-cell lymphoma/leukemia. Because primary mediastinal large B-cell lymphoma has in the past been frequently confused with germ cell tumors, pathologists should be aware of possible beta-hCG expression by lymphomatous cells to avoid the risk of misdiagnosis.

Adult↗

PubMed1999

Acute leukaemia immunophenotyping in bone-marrow routine sections.

Immunohistochemistry of acute leukaemias in bone-marrow paraffin sections is commonly thought to be useless because of the poor preservation of many lineage-related markers. The recent development of antibodies against fixative-resistant epitopes and of new antigen retrieval techniques, however, has expanded the possibility of accurately testing routine samples. To assess the relevance of paraffin section phenotyping in lineage determination, 110 examples of acute leukaemia were studied by specific antibodies against CD1a, CD3, CD15, CD20, CD34, CD68, CD79a, TdT, myeloperoxidase, glycophorin A, and factor-VIII-related antigen. The cases included 59 acute myeloid leukaemias, classified according to the FAB cooperative group criteria, 39 precursor B-cell acute lymphoblastic leukaemias (ALLs), seven T-ALLs, and five mixed precursor B-cell/myeloid acute leukaemias. The combination of the markers employed always allowed the identification of the cell lineage (myeloid, lymphoid or mixed) and, in some instances, of phenotypic profiles characteristic of distinct acute leukaemia subtypes. According to the results obtained, bone-marrow biopsy may be regarded as a reliable tool for acute leukaemia diagnosis; this observation is of practical relevance especially for the classification of cases which lack circulating blasts in the peripheral blood or showing dry tap at bone-marrow aspiration.

Acute Disease↗

PubMed1999

Retinoblastoma-related p107 and pRb2/p130 proteins in malignant lymphomas: distinct mechanisms of cell growth control.

pRb/p105, p107, and pRb2/p130 compose the retinoblastoma (RB) family of proteins and regulate cellular growth and differentiation. Because recent functional studies have indicated that the expression of the RB-related proteins p107 and pRb2/p130 are tightly cell cycle regulated, we were interested in investigating their expression along with cellular kinetic characteristics and proliferative features of non-Hodgkin's lymphomas (NHLs). p107 and pRb2/ p130 expression was determined immunohistochemically in biopsy specimens from 83 untreated patients with NHLs of various histiotypes. The expression of these two RB-related proteins was correlated with the mitotic index, apoptotic index, and percentages of Ki-67(+), cyclin A(+), p34(+), and cyclin B(+) cells. The overall survival rate was evaluated according to the Kaplan-Meier method and the log-rank test. We found a positive correlation between the percentages of cells positive for p107 and proliferative features such as mitotic index and percentage of Ki-67(+) and cyclin A(+) cells, whereas such correlation could not be demonstrated for the percentages of pRb2/p130 positive cells. Low immunohistochemical levels of pRb2/p130 detected in untreated patients with NHLs of various histiotypes inversely correlated with a large fraction of cells expressing high levels of p107 and proliferation-associated proteins. Such a pattern of protein expression is normally observed in continuously cycling cells. Interestingly, such cases showed the highest survival percentage (82.5%) after the observation period of 10 years. Thus, down-regulation of the RB-related pRb2/p130 protein could be one of the reasons why these cases display such a high rate of proliferation and why they respond so well to therapy.

Aged↗

PubMed1998

Solution structure of reduced monomeric Q133M2 copper, zinc superoxide dismutase (SOD). Why is SOD a dimeric enzyme?.

Copper, zinc superoxide dismutase is a dimeric enzyme, and it has been shown that no cooperativity between the two subunits of the dimer is operative. The substitution of two hydrophobic residues, Phe 50 and Gly 51, with two Glu's at the interface region has disrupted the quaternary structure of the protein, thus producing a soluble monomeric form. However, this monomeric form was found to have an activity lower than that of the native dimeric species (10%). To answer the fundamental question of the role of the quaternary structure in the catalytic process of superoxide dismutase, we have determined the solution structure of the reduced monomeric mutant through NMR spectroscopy. Another fundamental issue with respect to the enzymatic mechanism is the coordination of reduced copper, which is the active center. The three-dimensional solution structure of this 153-residue monomeric form of SOD (16 kDa) has been determined using distance and dihedral angle constraints obtained from 13C, 15N triple-resonance NMR experiments. The solution structure is represented by a family of 36 structures, with a backbone rmsd of 0.81 +/- 0.13 A over residues 3-150 and of 0.56 +/- 0.08 A over residues 3-49 and 70-150. This structure has been compared with the available X-ray structures of reduced SODs as well as with the oxidized form of human and bovine isoenzymes. The structure contains the classical eight-stranded Greek key beta-barrel. In general, the backbone and the metal sites are not affected much by the monomerization, except in the region involved in the subunit-subunit interface in the dimeric protein, where a large disorder is present. Significative changes are observed in the conformation of the electrostatic loop, which forms one side of the active site channel and which is fundamental in determining the optimal electrostatic potential for driving the superoxide anions to the copper site which is the rate-limiting step of the enymatic reaction under nonsaturating conditions. In the present monomer, its conformation is less favorable for the diffusion of the substrate to the reaction site. The structure of the copper center is well-defined; copper(I) is coordinated to three histidines, at variance with copper(II) which is bound to four histidines. The hydrogen atom which binds the histidine nitrogen detached from copper(I) is structurally identified.

Amino Acid Substitution↗

PubMed1998

The EnVision++ system: a new immunohistochemical method for diagnostics and research. Critical comparison with the APAAP, ChemMate, CSA, LABC, and SABC techniques.

AIM: To assess a newly developed immunohistochemical detection system, the EnVision++. METHODS: A large series of differently processed normal and pathological samples and 53 relevant monoclonal antibodies were chosen. A chessboard titration assay was used to compare the results provided by the EnVision++ system with those of the APAAP, CSA, LSAB, SABC, and ChemMate methods, when applied either manually or in a TechMate 500 immunostainer. RESULTS: With the vast majority of the antibodies, EnVision++ allowed two- to fivefold higher dilutions than the APAAP, LSAB, SABC, and ChemMate techniques, the staining intensity and percentage of expected positive cells being the same. With some critical antibodies (such as the anti-CD5), it turned out to be superior in that it achieved consistently reproducible results with differently fixed or overfixed samples. Only the CSA method, which includes tyramide based enhancement, allowed the same dilutions as the EnVision++ system, and in one instance (with the anti-cyclin D1 antibody) represented the gold standard. CONCLUSIONS: The EnVision++ is an easy to use system, which avoids the possibility of disturbing endogenous biotin and lowers the cost per test by increasing the dilutions of the primary antibodies. Being a two step procedure, it reduces both the assay time and the workload.

Antibodies, Monoclonal↗

PubMed1998

Anaplastic large cell lymphoma: a concept reviewed.

The development of the concept of anaplastic large cell lymphoma is reviewed. The subtypes of the tumor proposed in the literature, including the so-called Hodgkin's-like variant, are discussed both on morphological and clinical grounds. The more recent information on the genetic and molecular characteristics of the tumor (i.e. 2;5 translocation, formation of the NPM/ALK hybrid gene, and production of a specific protein) are presented: their possible implications in the future classification and clinical management of the neoplasm are discussed.

Journal Article↗

PubMed1998

Concurrence of localized Castleman's disease and peripheral small B-Lymphocytic lymphoma within the same lymph node.

Castleman's disease, also known as benign giant lymph node hyperplasia, is a lymphoproliferative disorder which can occur either in a localized or multicentric form. The latter is characterized by the development of malignant lymphoma, Kaposi's sarcoma or carcinoma in 32% of cases. By contrast, localized Castleman's disease has exceptionally been reported in association with non-Hodgkin's lymphoma and - to the best of our knowledge - never at the same anatomic site. Here we describe the occurrence in the same lymph node of localized Castleman's disease (with monotypic plasma cell component) and an apparently unrelated peripheral small B-lymphocytic lymphoma.

Aged↗

PubMed1997

ePHOGSY experiments on a paramagnetic protein: location of the catalytic water molecule in the heme crevice of the oxidized form of horse heart cytochrome c.

The hydration properties of the oxidized form of horse heart cytochrome c have been studied by 1H NMR spectroscopy. Application of ePHOGSY (enhanced protein hydration observed through gradient spectroscopy) experiments over a paramagnetic molecule provided firm spectroscopic evidence of the presence of a water molecule in the heme crevice. A few intermolecular NOEs have been used to locate the water molecule at about 0.65 nm away from the iron atom and to compare the position observed in solution with that observed in the crystal structure and in solution for the reduced state. The resulting picture is that there is a detectable movement of the water molecule upon oxidation.

Animals↗

PubMed1997

Characterization of a partially unfolded high potential iron protein.

A partially unfolded state of the Fe4S4-containing high potential iron-sulfur protein from Chromatium vinosum has been detected and characterized by NMR spectroscopy following addition of a concentrated solution of guanidinium chloride to the native protein. This intermediate species (i) maintains the polymetallic center, (ii) exhibits a largely collapsed secondary structure, and (iii) undergoes fast cluster decomposition upon oxidation. This information is framed into the knowledge about this class of proteins, and the possible role of this intermediate with respect to the in vivo folding/unfolding process is discussed as well its role in the slow hydrolytic degradation characteristic of oxidized HiPIPs.

Chromatium↗

PubMed1997

Paramagnetic NMR spectroscopy of native and cobalt substituted manganese superoxide dismutase from Escherichia coli.

Manganese containing superoxide dismutase from E. coli has been investigated through paramagnetic NMR spectroscopy. The spectrum of the native form was rationalized using a tau(s) = 3x10(-11) s for the Mn(III) ion, consistent with previous estimates from NMRD measurements. Mn(III) has been replaced by a Co(II) ion and a tentative assignment of the NMR spectrum of the Co(II)-substituted derivative has been proposed, based on T1, chemical shifts and 1D-NOE data. The metal coordination geometry is provided by three histidines and a carboxylate group. The presence of a solvent molecule as a loosely bound fifth ligand is also proposed. The NMR data of the Co(II)-substituted derivative of E. coli MnSOD differs from those of Co(II)SOD from other bacterial sources. This suggests that Co(II) substitution is an efficient method to address the problem of metal ion selectivity in superoxide dismutase.

Escherichia coli↗

PubMed1997

Antigen retrieval techniques in immunohistochemistry: comparison of different methods.

Routine sections of normal and pathological samples fixed in 10 per cent buffered formalin or B5, including EDTA-decalcified bone-marrow biopsies, were tested with 61 antibodies following heating in three different fluids: 0.01 M citrate buffer (pH 6.0), 0.1 M Tris-HCl (pH 8.0), and 1 mM EDTA-NaOH solution (pH 8.0). The sections underwent either three cycles of microwave treatment (5 min each) or pressure cooking for 1-2 min. The alkaline phosphatase/anti-alkaline phosphatase (APAAP) technique was used as the standard detection method; with 16 antibodies a slightly modified streptavidin-biotin complex (SABC)-immunoperoxidase technique was applied in parallel. The results obtained were compared with those observed without any antigen retrieval (AR), or following section digestion with 0.05 per cent protease XIV at 37 degrees C for 5 min. Chess-board titration tests showed that all antibodies but one profited by AR. Protease XIV digestion represented the gold standard for five antibodies, while 55 produced optimal results following the application of heat-based AR. By comparison with the other fluids, EDTA appeared to be superior in terms of both staining intensity and the number of marked cells. These results were independent of tissue processing, immunohistochemical approach, and heating device. Pressure cooking was found to be more convenient on practical grounds, as it allowed the simultaneous handling of a large number of slides and a time saving of 1 min 30 s, representing the proper time for the treatment.

Antigens↗

PubMed1997

Peripheral T-cell lymphomas. Clinico-pathologic study of 168 cases diagnosed according to the R.E.A.L. Classification.

BACKGROUND: One hundred sixty-eight peripheral T-cell lymphomas (PTCLs) were reviewed according to the Revised European-American Lymphoma (R.E.A.L.) Classification. PATIENTS AND METHODS: The cases, originally diagnosed on the basis of the Updated Kiel Classification (UKC), were all provided with histological preparations, immunophenotype, clinical information, and follow-up data. The slides were reclassified by five observers, who integrated the R.E.A.L. criteria with cell size measurements. The prognostic value of clinical and pathologic findings was assessed by univariate and multivariate analysis. RESULTS: The R.E.A.L. Classification was reproducibly applied by all of the observers. Clinically, anaplastic large cell lymphomas (ALCLs) differed from the remaining PTCLs by mean age (29.5 vs. 52.9 years), bulky disease (52.3% vs. 11.3%; P = 0.000), mediastinal mass (52.7% vs. 32%; P = 0.004), and disease-free survival (68.0% vs. 38.2%; P = 0.0001). Although each histological type displayed specific clinical aspects, PTCLs other than ALCL were basically characterised by a poor clinical outcome which was not influenced by the UKC malignancy grade. At multivariate analysis, the risk of a lower complete remission rate was related to bulky disease (P = 0.001), histologic group (non-ALCL) (P = 0.01), and advanced stage (III-IV) (P = 0.0002). CONCLUSIONS: The present study supports the classification of T-cell lymphomas proposed by the R.E.A.L. scheme.

Adolescent↗

PubMed1997

Pyothorax-associated lymphoma: description of the first two cases detected in Italy.

BACKGROUND: Pyothorax-associated lymphoma (PAL) is a rare, but distinct, clinico-pathologic entity which occurs most often in Japanese people; to the best of our knowledge, only six cases of it have been reported in Western countries. The tumour develops several decades following artificial pneumothorax or chronic pleuritis due to tuberculous infection, produces pleural effusion associated with extensive local lymphomatous infiltrates, and is sustained by a polymorphic large B-cell clonal proliferation showing EBV integration in the genoma of the neoplastic cells. PATIENTS AND METHODS: Herein we describe two cases of PAL observed in Italian patients, both extensively studied on the clinical, pathological, phenotypic, virological, and molecular levels. RESULTS: The two cases occurred, respectively, 45 and 50 years after therapeutic pneumothorax because of tuberculous pleuritis and were characterized by a pleural mass extending to the thoracic wall, which on histological examination were seen to consist of large elements with immunoblastic morphology. Immunohistochemistry show monotypic restriction of Ig light chains, as well as the expression of CD45, B-cell markers (CD20, CD79a, CD45RA), bcl-2 oncogene product, EBNA-2 and, partially, LMP-1. The ratio of cycling cells was extremely high as was the number of mitotic figures. In situ hybridization displayed the presence in the neoplastic cells of the EBV-related small RNAs EBER 1 and 2, which in turn, along with the positivity for EBNA-2 and LMP-1, further strengthened the close relationships between PAL and latent viral infection. Molecular studies revealed, on one hand, clonal rearrangement of the Ig heavy chain J region genes, and on the other, negativity for HHV8 in one case and positivity in the other. CONCLUSIONS: These cases of PAL are the first to be documented in Italy; they serve to direct attention to the fact that this condition is not confined to Japanese people, and that its occurrence in Western countries might be underestimated.

Aged↗

PubMed1997

Immunohistochemistry of bone-marrow biopsy.

In a percentage of cases, conventional morphologic evaluation of bone-marrow needle biopsy (BMNB) in insufficient to achieve a firm diagnosis. Under these circumstances, immunohistochemistry plays a basic role, providing an easy and objective key for the interpretation of the pattern observed in most instances. Herein, the authors focus on the technical procedures, which allow extensive application of immunohistochemistry to the study of BMNB, as well as on the panels of antibodies needed for the identification of the most relevant conditions.

Antigens, CD↗

PubMed1997

Frequent expression of the NPM-ALK chimeric fusion protein in anaplastic large-cell lymphoma, lympho-histiocytic type.

The revised European-American lymphoma classification recognizes a subtype of anaplastic large-cell lymphoma (ALCL), termed lympho-histiocytic because of its peculiar cytological composition. As in the case of classical ALCL, this tumor usually occurs in young patients and shows an excellent response to chemotherapy, but some authors have suggested that in reality this is a nonanaplastic T-cell lymphoma rich in histiocytes. In this paper, we show that three of five cases of lympho-histiocytic ALCL stain with anti-ALK antibodies and can therefore be presumed to express the chimeric NPM/ALK protein secondary to (2;5) translocation. These findings further support the inclusion of this as a type of ALCL and not among the nonanaplastic peripheral T-cell lymphomas. Furthermore, they indicate that staining for ALK proteins is a powerful tool for the diagnosis of lympho-histiocytic ALCL, the recognition of which may be difficult on morphological grounds.

Adolescent↗