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Biomedical subjects

A Orazi

Publications and source records attributed to A Orazi.

At least 73 records · Page 4Linked to original sources
PubMed1993

Hematopoietic lineage- and stage-restricted expression of the ETS oncogene family member PU.1.

The ETS oncogene family member PU.1 is a transcriptional activator that is dysregulated by Friend erythroleukemia virus insertion. Northern analysis found that PU.1 is highly expressed in cells of myeloid and B-lymphoid origin, but not expressed at all in a number of nonhematopoietic tissues. Interferon-gamma and retinoic acid downregulated PU.1 expression in marrow macrophages. In situ immunohistochemistry found that PU.1 is expressed only in early granulocytic and erythroid cells and megakaryocytes, but not in mature erythroid cells, mature granulocytes, endothelial cells, or osteocytes. Thus, its expression pattern makes PU.1 a candidate for a genetic determinant of lineage commitment and stage progression in blood cell development. It also lends insight into how PU.1 might play a role in Friend virus erythroleukemia.

Animals↗
PubMed1993

In vivo administration of recombinant methionyl human stem cell factor expands the number of human marrow hematopoietic stem cells.

A growing number of in vitro studies suggest that recombinant human stem cell factor (SCF) is capable of augmenting the proliferative capacity of human hematopoietic progenitor cells (HPC) and stem cells (HSC). We further evaluated this biologic effect by analyzing the response of bone marrow (BM) HPCs and HSCs to the administration of SCF in eight patients with locally advanced or metastatic breast cancer who were enrolled in an ongoing phase I study. SCF was administered for 14 days by daily subcutaneous injection at dosages of 10, 25, or 50 micrograms/kg/d. BM CD34+ HLA-DR+ and CD34+ HLA-DR- CD15- cells, previously shown by our laboratory to be enriched for various classes of differentiated and primitive HPCs, respectively, were quantitated in BM samples on day 0 (pretreatment) and day 15 (posttreatment). These CD34+ HLA-DR+ and CD34+ HLA-DR- CD15- cells were then isolated by cell-sorting and assayed for several classes of HPCs, including the high--proliferative potential colony-forming cell (HPP-CFC), the burst-forming unit--megakaryocyte (BFU-MK), and the long-term BM culture--initiating cell (LTBMC-IC). SCF administration resulted in a 3.3-fold (range, 1.4- to 18.8-fold; P = .018) increase in the absolute numbers of CD34+ cells, a 3.7-fold (range, 1.2- to 8.2-fold; P = .028) increase in the absolute numbers of CD34+ HLA-DR+ cells, and a 2.4-fold (range, 1.1- to 29.3-fold; P = .010) increase in the absolute numbers of CD34+ HLA-DR- CD15- cells. Following the infusion of SCF, a statistically significant increase in the absolute numbers of HPP-CFC (P = .018), BFU-MK (P = .046), CFU-granulocyte, erythrocyte, monocyte, megakaryocyte (CFU-GEMM: P = .043), BFU-erythrocyte (BFU-E; P = .043), CFU-granulocyte, macrophage (CFU-GM; P = .045), and CFU-megakaryocyte (CFU-MK; P = .028) per milliliter of marrow was observed. Stromal cell-free LTBMCs supplemented with SCF and interleukin-3 (IL-3), initiated with CD34+ HLA-DR- CD15- cells obtained on day 0, produced viable cells for 9.6 weeks, compared with 11.5 weeks for LTBMCs initiated with CD34+ HLA-DR- CD15- cells obtained on day 15. Cumulative cellular production by LTBMCs initiated with day 15 CD34+ HLA-DR- CD15- cells was statistically greater than that by day 0 LTBMCs (P = .031). These same cultures produced CFU-GM for 6.3 weeks (day 0) versus 9 weeks (day 15).(ABSTRACT TRUNCATED AT 400 WORDS)

Antigens, CD↗
PubMed1993

Hematopoietic precursor cells within the yolk sac tumor component are the source of secondary hematopoietic malignancies in patients with mediastinal germ cell tumors.

BACKGROUND: Patients with mediastinal germ cell tumors (MGCT) have a high incidence of hematologic malignancies unrelated to cytotoxic chemotherapy. It has been suggested that these leukemic conditions originate from a MGCT progenitor cell capable of undergoing non-germ cell (hematopoietic) differentiation. METHODS: To assess this hypothesis, histologic material from six patients with MGCTs associated with leukemia was examined using monoclonal and polyclonal antibodies capable of labeling cells of the different marrow cell lineages. RESULTS: Morphologically identifiable hematologic cells were found within the yolk sac tumor component of the MGCT in four of these patients. In three of the four cases, the cells consisted of poorly differentiated blast cells, whereas in the fourth, clusters of erythroblasts were identified. The leukemic cells within the MGCT and in the bone marrow had similar morphology, constant expression of the early progenitor cell marker CD34, and variable expression of more mature myeloid, monocytic, erythroid, and megakaryocytic markers. Three cases expressed p53, a nuclear protein associated with neoplastic transformation in a wide range of malignancies, including testicular cancers, but which rarely is reported in leukemias. Karyotype of the leukemia was assessed in five cases: two showed an i(12p), a cytogenetic marker of GCT not identified in the usual cases of leukemia. CONCLUSIONS: The results support the hypothesis that these leukemic conditions originate in the MGCT through a mechanism of differentiation from a yolk sac tumor-derived progenitor cell, with subsequent homing to the marrow.

Adolescent↗
PubMed1993

Bone marrow stroma in humans: anti-nerve growth factor receptor antibodies selectively stain reticular cells in vivo and in vitro.

Two anti-nerve growth factor receptor (LNGFR or p75NGFR) antibodies, Me20.4 and Me8211, label stromal cells with dendritic features in fresh smears and in formalin-fixed, paraffin-embedded human bone marrow (BM). The LNGFR+ cells have an oval nucleus, a scanty cytoplasm with long dendrites that intermingle with the hematopoietic cells, line the abluminal side of sinus endothelial cells, and provide the scaffold for the hematopoietic marrow. At the electron microscopy level, the immunogold tag labels the body and the long branching dendrites of fibroblast-like cells with scanty cytoplasm containing mitochondria, endoplasmic reticulum, and dense bodies. The LNGFR+ cells are positive for alkaline phosphatase, reticulin, collagen III, vimentin, TE-7, and CD13 but negative for endothelial (vWF, CD34, Pal-E), neural (CD56, neurofilament) and leukocyte markers (CD45, CD68). The LNGFR+ stromal cells appear in the fetal BM before the hematopoietic activity begins, originate from the vessel adventitia, and radiate in the Bm cavity. Long-term BM culture (LTBMC) in vitro contain LNGFR+ stromal cells. We document the presence of RNA message for the low- (LNGFR) and the high-affinity NGF receptor (NTRK1) by using RT-PCR on fresh BM aspirate and on LTBMC. BM biopsies from patients with hematologic fibrogenic diseases and in cytokine-treated cancer patients are evaluated for LNGFR+ cells: the amount of stained cells is correlated with the traditional reticulin stain in cases of myelofibrosis, therapy-related myelodysplasia, leukemia, and detected an increase of stromal cells in cytokine-treated patients. The anti-LNGFR antibodies represent a specific membrane marker for the adventitial reticular cells (ARC) of the human marrow and allow precise evaluation and quantitation of this important BM microenvironment component in vivo and in vitro.

Adult↗
PubMed1993

Primary hepatic B-cell lymphoma in a child.

Lymphoma arising in the liver is uncommon in adults and rare in children. A 12-year-old boy with hepatomegaly and jaundice had a calcified intrahepatic large-cell lymphoma of B-cell origin that expressed bcl-2 protein and had near-tetraploid chromosome number with a t(8;14) (q24;q32) and a homogeneously staining region (HSR). This tumor, only the fourth example of primary hepatic lymphoma in a child, has the rare finding of an HSR before treatment and is the first human lymphoma with t(8;14) that expresses bcl-2 protein. In addition, the demonstration of extensive calcification in the tumor by computed tomography scan is highly unusual for lymphoma. Lymphoma must be considered in the differential diagnosis of primary liver tumors in children and adults, especially if the serum alpha-fetoprotein level is normal.

Child↗
PubMed1993

Proliferating normal bone marrow cells do stain for Ki-67 antigen.

The normal human bone marrow has been investigated in the past for the presence of the proliferation associated antigen detected by the Ki-67 antibody and aberrantly low scores for this antigen have been reported. We used a new Ki-67 equivalent antibody (MIB 1) and a formalin fixation of smears and trephine biopsies, and we report 52.8% +/- 9.2 SD of the normal BM cells to stain for MIB 1. Late forms of the maturing blood cells compartment such as metamyelocytes and megakaryocytes were stained in cytokine-treated marrows.

Bone Marrow↗
PubMed1993

Therapy-related myelodysplastic syndromes: FAB classification, bone marrow histology, and immunohistology in the prognostic assessment.

In this study we describe the morphologic and immunohistochemical evaluation of bone marrow biopsies from 14 patients with therapy-related myelodysplastic syndromes (t-MDS). We employed CD34, anti-HLA-Dr, anti-elastase, CD68, anti-glycophorin, CD61 monoclonal antibodies immunostaining, and enzyme histochemistry for chloroacetate esterase. Moreover, we used PC10, a MAb raised against the proliferating cell nuclear antigen, to study the proliferative capacity of these marrows. Our data suggest that diagnosis of refractory anemia with excess of blasts (versus chronic myelomonocytic leukemia), the abnormal localization of immature precursors, marrow fibrosis, and augmented CD34 expression in the bone marrow biopsy are ominous prognostic factors at a statistically significant level (p < 0.0005). A combined morpho-immunohistochemical analysis of bone marrow biopsy correctly classifies t-MDS cases according to the biologic and clinical aggressiveness.

Antibodies, Monoclonal↗
PubMed1993

Frequent p53 overexpression in therapy related myelodysplastic syndromes and acute myeloid leukemias: an immunohistochemical study of bone marrow biopsies.

p53 overexpression was studied immunohistochemically in paraffin-embedded bone marrow biopsies using a recently described technique for antigen retrieval based on microwave oven heating of paraffin sections. Using a monoclonal antibody (PAb1801) that reacts with human cellular p53, nuclear staining was detected in 7/11 (63%) therapy-related myelodysplastic syndromes and in 3/4 (75%) therapy-related acute myeloid leukemias. Conversely, staining for p53 was seen only in 9/40 (22%) cases of "primary" hematologic conditions (P < 0.007); these included myelodysplastic syndromes [#2], acute myeloid leukemia [#4], and chronic granulocytic leukemia in accelerated phase or blast crisis [#3]. Biopsies of normal controls and of chronic granulocytic leukemia in stable phase were consistently p53(-). Nine of the 10 karyotyped p53(+) acute myeloid leukemia/myelodysplastic syndrome cases showed complex cytogenetic findings with frequent involvement of chromosome 5 and/or 7. Only four of the 33 karyotyped p53(-) cases showed similar cytogenetic changes. Chromosome 17 involvement was present in four of 13 (31%) cytogenetically assessed p53+ cases, but in none of the p53(-). In univariate analysis, p53 expression in both MDS and AML was significantly associated with shorter survival. The frequent overexpression of p53 in therapy-related myelodysplastic syndromes, therapy-related acute myeloid leukemias and in accelerated phase/blast crisis, chronic granulocytic leukemia and its strong association with complex karyotypes suggests an important role of this gene in the pathogenesis of these leukemic conditions.

Acute Disease↗
PubMed1992

Recombinant human interleukin-3 and recombinant human granulocyte-macrophage colony-stimulating factor administered in vivo after high-dose cyclophosphamide cancer chemotherapy: effect on hematopoiesis and microenvironment in human bone marrow.

The effects on bone marrow (BM) cell proliferation and differentiation of recombinant human interleukin-3 (rhIL-3) and recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) administered after high-dose (7 g/m2/d) cyclophosphamide (HD-CTX) chemotherapy were studied in nine patients with malignancies without BM involvement and in three control patients. rhIL-3 at a dose of 1 to 5 micrograms/kg/day was administered for 14 to 18 days by continuous intravenous (i.v.) infusion and rhGM-CSF was administered at a dose of 5.5 micrograms/kg/day for 14 days. Changes induced by cytokine treatment were assessed by morphoimmunohistochemical analysis of BM biopsies. Comparison was made in the cytokine-treated groups and with control patients who received HD-CTX alone. BM cellularity and the myeloid/erythroid (ME) ratio were lower in rhIL-3-treated than in rhGM-CSF-treated patients, but in both groups it was significantly higher than in the controls. The proportion of BM cells stained by PC10, a monoclonal antibody (MoAb) recognizing a proliferation-associated nuclear protein (PCNA), increased from 6.78% to 21.18% (P less than .02) after rhIL-3, and from 5% to 35.33% (P less than .001) after rhGM-CSF; no increase was observed in the control group. The frequency of CD34+ BM cells was unchanged after rhIL-3 (P = NS) and decreased after rhGM-CSF (P less than .001). In both groups, most of the PC10+ cells were represented by promyelocytes and myelocytes with no increase in blast cell numbers. rhIL-3-treated BM showed an increased number of megakaryocytes and increased proliferative activity of erythroid cells as compared with rhGM-CSF cases. BM stroma changes observed in both treated groups included endothelial cell proliferation, increased BM macrophage concentration, and increase in BM fibroblasts as detected with an anti-nerve growth factor receptor antibody. In most rhIL-3-treated cases, BM fibrosis developed after treatment. The same effect was not observed in rhGM-CSF patients.

Adult↗
PubMed1992

Phenotypic and functional analysis of lymphocytes infiltrating paediatric tumours, with a characterization of the tumour phenotype.

Tumour-infiltrating lymphocytes (TIL) of paediatric tumours obtained from 37 lesions of different histotype (12 osteosarcomas, 5 Wilms' tumours, 7 soft-tissue sarcomas, 5 neuroblastomas and 8 miscellaneous) were studied to establish their potential for therapy. Fresh isolated TIL were cultured for the first 2 weeks with low doses of interleukin-2 (IL-2) (20 Cetus U/ml) to select for "tumour-specific" lymphocytes potentially present in the neoplastic lesion, followed by culture with high doses of IL-2 (1000 Cetus U/ml) to achieve TIL expansion. TIL were grown with more than 10-fold expansion in only 9 cases (mean expansion: 58-fold, range 13.5-346). In 17 cases no viable cells were obtained. After 30 days of culture with IL-2 the proliferative ability of TIL declined sharply in the majority of cases and TIL became refractory to any further stimulus, including addition of IL-4, tumour necrosis factor alpha (TNF alpha) or interferon gamma, and activation with OKT3 in solid phase. In 20 out of 37 cases TIL were available for phenotypic and functional analysis. TIL after long-term culture were predominantly CD3+ but 2 cases of osteosarcoma showed a predominance of CD3+TcR gamma/delta cells. The CD4/CD8 ratio was more than 1 in 10 cases, without correlation with tumour histology, site of lesion or TIL growth. The number of CD16+ and CD25+ lymphocytes decreased progressively during culture, the latter concomitantly with a reduction of TIL growth rate. The lytic pattern of TIL against allogenic and autologous tumour (Auto-Tu) cells was variable, but specific lysis of Auto-Tu was seen in only one case (Wilms' tumour) after culture with TNF alpha and irradiated Auto-Tu cells. The immunohistochemical analysis of tumour lesions revealed a limited lymphocyte infiltrate, a low expression of histocompatibility leukocyte antigens (HLA) class I and of the adhesion molecules ICAM1, LFA3, and a significant production of transforming growth factor beta (TGF beta). These data indicate that TIL obtained from paediatric patients are difficult to expand at levels required for immunotherapy and lack a significant number of tumour-specific T lymphocytes. A low expression of immunomodulatory molecules on tumour cells or the production of suppressive factors may prevent activation and expansion of TIL in paediatric tumours.

Antigens, CD↗
PubMed1992

Increased susceptibility to lymphokine activated killer (LAK) lysis of relapsing vs. newly diagnosed acute leukemic cells without changes in drug resistance or in the expression of adhesion molecules.

The NK and LAK activity of peripheral blood lymphocytes of leukemic patients as well as the susceptibility of their acute myeloid (AML) and lymphoblastic (ALL) leukemia cells to autologous and allogeneic LAKs were examined. In addition, neoplastic cells at diagnosis and at relapse were compared in the same patients for several features, including in vitro susceptibility to LAKs and to the drugs used in the induction phase, expression of MDR phenotype and of adhesion molecules, and differentiation markers. The NK activity of patients' LAK cells on K562 was significantly lower than that of a group of healthy donors whereas no differences were found in LAK activity as evaluated on Daudi cells. Three of 5 AML and 3 of 4 ALL were significantly more susceptible to autologous and allogeneic LAK lysis when blasts obtained at relapse were compared with leukemic cells of the same patients at diagnosis. This different lysability was not associated with in vitro modified sensitivity to drugs used in induction treatment. Moreover, no elevation in the expression of the multidrug-resistance (MDR)-related P170 glycoprotein was noted in relapsing leukemic cells. Even the expression of adhesion molecules and differentiation markers did not correlate with lysability of leukemic cells. These data demonstrate that relapsing leukemic blasts can be significantly lysed by LAK cells and suggest a rationale for adoptive immunotherapy with IL-2 and LAK cells in the treatment of acute leukemic patients.

Adult↗
PubMed1992

A cystic partially differentiated nephroblastoma producing alpha-fetoprotein.

A case of cystic partially differentiated nephroblastoma with immunohistochemical and serological demonstration of alpha-fetoprotein (AFP) production is described. To our knowledge, this is the first such case reported. The morphological heterogeneity of this rare tumor led us to describe the criteria of its nosological classification and of its differential diagnosis with intrarenal teratoma. AFP, besides being a marker of germline-derived tumor, was associated to this rare variant of Wilm's tumor. Although the tumor did not show regression either on clinical or pathologic assessments, serum AFP levels decreased after preoperative chemotherapy and returned to normal limits after nephrectomy.

Biomarkers, Tumor↗
PubMed1991

Myelodysplastic syndrome with increased marrow fibrosis: a distinct clinico-pathological entity.

Seventeen cases of myelodysplastic syndrome (10 primary and seven secondary to previous radio-chemotherapy), characterized by trilineage dysplasia, severe bone marrow fibrosis and a high number of megakaryocytes, are described. All of these patients had similar clinical and prognostic features consisting of pancytopenia, modest or absent visceral enlargement and poor survival. The use of CD61 antibodies, which recognize megakaryocytic cells at all stages of maturation, confirmed that these patients had a higher number of these cells than either normal subjects or patients affected by myelodysplastic syndrome (MDS) without fibrosis. Furthermore, primary and secondary MDS with fibrosis, although clinically and histopathologically similar, differed in terms of the number of megakaryoblasts which were significantly higher in primary forms (P less than 0.02). We conclude that MDS with fibrosis may represent a clinicopathological entity which needs to be distinguished from other MDS subtypes as well as from idiopathic myelofibrosis or malignant myelosclerosis.

Antibodies, Monoclonal↗
PubMed1991

Selective purging by human interleukin-2 activated lymphocytes of bone marrows contaminated with a lymphoma line or autologous leukaemic cells.

The ability of recombinant interleukin 2 (rIL2) activated lymphocytes (LAK) to purge BM samples contaminated by tumour cells was evaluated. Human BM mononuclear cells were contaminated with 10% of the lymphoma line CA46 and then cultured in liquid medium containing 1000 U/ml of rIL2 and/or LAK autologous to the used BM. At the end of coculture the growth of residual tumour cells and of CFU-GM were evaluated by clonogenic assay. No tumour cell growth was observed in 5/5 independent experiments after 18 h of coculture with LAK. No significant inhibition of CFU-GM growth was also noted. Subsequently, the effect of LAK on BM obtained from four leukaemic patients and contaminated with 20-50% of their own AML and ALL cells was studied using MAb as a tool for identifying leukaemic cells. LAK eliminated 24-78% of contaminating cryopreserved uncultured autologous leukaemic cells. In five cases the BM was contaminated by a low (2%) amount of ALL cells. In these patients the monoclonal heavy chain rearrangement typical of ALL was no longer visible after coculture with LAK. Evidence for selective tumour cytotoxicity by LAK was confirmed by using autologous BM cells as hot and cold targets in a 51Cr release assay. Finally, successful haematologic reconstitution of lethally irradiated BALB/c mice was obtained using syngeneic BM cocultured with LAK. These results support the investigational use of rIL2 and LAK in the treatment of human leukaemia.

Acute Disease↗
PubMed1991

Distinct morphophenotypic features of chronic B-cell leukaemias identified with CD1c and CD23 antibodies.

Morphological criteria usually applied to diagnose various subtypes of B-cell chronic lymphoid leukaemia are largely subjective. Immunophenotyping of 61 relevant cases using a selected panel of monoclonal antibodies (mAb), showed that CD1c and CD23 mAb were able to separate B-cell chronic lymphocytic leukaemia (B-CLL) from other chronic B-cell lymphoproliferative diseases. Lymphocytes of B-CLL were CD1c-, CD23+, whereas those of other types of chronic B-cell leukaemia were CD1c+/-, CD23-, and CD38/-. Non-B-CLL cases had a significantly higher amount of large peroxidase-negative (unstained) cells analyzed with an automated blood cell counter (Technicon H6000). This type of volumetric assessment allowed a separation between typical and "atypical" B-CLL, which otherwise were both CD1c-, and CD23+. These combinations of phenotypic markers corresponded to well-defined haematopathologic entities, conventionally diagnosed on peripheral blood (PB) and bone marrow smears, and on histologic sections of lymph nodes and spleen.

Antibodies, Monoclonal↗
PubMed1991

Identification of CD34+ cells in normal and pathological bone marrow biopsies by QBEND10 monoclonal antibody.

Monoclonal antibody QBEND10 is reactive with the CD34 antigen in aldehyde-fixed, decalcified, paraffin-embedded bone marrow biopsies. In normal bone marrow it stained endothelial cells lining arterioles and capillaries, sinusoidal (littoral) cells and 0.89% of all haemopoietic cells. QBEND10+ mononuclear cells were seen as isolated, randomly distributed mononuclear cells in normal and regenerating bone marrows. Conversely, QBEND10+ cells were increased and present in aggregates of three or more cells in 6/8 cases of acute leukemia; in two cases of CD34-negative leukemia and in two patients after complete remission no aggregates were seen. QBEND10 immunohistochemistry may therefore be useful for diagnosis and follow-up of myeloid leukemias. In addition, increased numbers of CD34+ cells arranged in clusters were seen in 4/9 cases of refractory anemia with excess blasts (RAEB), 1 case of chronic myelomonocytic leukemia, 3/3 cases of RAEB in transformation, and in 3/7 cases of chronic myelogenous leukemia: in all these cases, CD34 staining of the bone biopsy may have prognostic value. QBEND10+ endothelial cells were significantly increased in all the pathological conditions examined (1.43% of all nucleated cells versus 0.80% in normal bone marrow; p = 0.0063), but especially in myeloid leukemias and in two fibrotic syndromes examined.

Anemia, Refractory, with Excess of Blasts↗