PubMed Health⌕ Search

Biomedical subjects

R Foà

Publications and source records attributed to R Foà.

At least 73 records · Page 4Linked to original sources
PubMed1987

Germ-line configuration of the T-cell receptor beta-chain gene in B-cell chronic lymphoproliferative disorders which co-express T-cell antigens.

In 7 cases of chronic B-cell lymphoproliferative disorders-6 chronic lymphocytic leukaemias and 1 non-Hodgkin lymphoma in leukaemic phase--which co-expressed T-cell markers (CD3, CD2) the clonal origin was investigated at the DNA level. In accordance with the diagnosis, all cases showed a monoclonally rearranged configuration of the immunoglobulin genes. On the contrary, the T-cell receptor beta chain gene always retained a germ-line organization. These findings demonstrate that B-cell chronic lymphoproliferative disorders which co-express T-cell-related markers are truly composed of monoclonal B-cell elements.

Antigens, Differentiation, T-Lymphocyte↗
PubMed1986

Serial transplantation of a human acute T lymphoblastic leukemia into nude mice.

A human acute T lymphoblastic leukemia line (PF-382) was serially transplanted into nude mice. No takes were observed in untreated nude mice, whereas solid tumors were observed in splenectomized and total body, sublethally irradiated mice. The minimal tumor-inducing dose and the latency time remained unchanged after the third and fifth serial transplants. Moreover, leukemic cells recovered from the 8th in vivo passages displayed the same differentiation antigens and chromosomal markers as the in vitro PF-382 cell line used for the first transplant. This stable and well-characterized experimental system could be a new model for T-lymphocyte differentiation and immune-reactivity against human leukemias.

Animals↗
PubMed1986

Normal T-lymphocyte function in patients with Hodgkin's disease in long-lasting remission.

In 18 patients with Hodgkin's disease (HD) in long-lasting remission (more than 5 years), the distribution of circulating T-lymphocytes was analyzed using a series of monoclonal antibodies (OKT3, T4, T8, Leu-7, Leu-11 and T10) and correlated with cell function (helper capacity in a pokeweed mitogen system and natural killer (NK) activity). A reduced proportion of OKT4 (helper/inducer)-positive cells associated with a normal absolute number was consistently accompanied by a significant increase (p less than 0.005) in the proportion and absolute number of OKT8 (suppressor/cytotoxic)-positive cells. The OKT4-positive cells, despite their moderate percentage reduction, showed normal helper activity. A more extensive characterization of the lymphoid population in these patients documented a preserved cytotoxic function in a 51Cr release assay and increased proportion of cells expressing NK-associated antigens (Leu-7, Leu-11, OKT10) with a high number of cells coexpressing OKT8 and Leu-7. It is suggested that in patients with Hodgkin's disease in long-lasting remission no laboratory (or clinical) evidence of cellular immunodeficiency can be documented.

Adult↗
PubMed1985

Multimarker phenotypic characterization of adult and childhood acute lymphoblastic leukaemia: an Italian multicentre study.

A multicentre phenotypic study was carried out in Italy combining conventional immunological techniques with monoclonal antibody (MoAb) analysis in 190 cases of adult and childhood acute lymphoblastic leukaemia (ALL), in an attempt to define better the lineage relationship of the neoplastic cells. Of the 140 children evaluated, 79.3% expressed the common ALL (cALL) antigen (all analyses performed by MoAb), 11.4% were T-ALL and 9.3% were non-T, non-B, non-common ('null') ALL. The proportion of adult cALL cases was slightly lower (64% of the 50 cases studied) than that of childhood ALL, whilst the incidence of T-ALL was significantly higher in adults than in children (26% v. 11.4%, P less than 0.05). Because of the high proportion of cALL cases, the incidence of 'null' ALL in adult patients was similar (10%) to that of children, and lower than previously reported. The recognition of early pre-T-ALL cases (T1+, RFT2+, T10+, T6-, T11-, E-) contributed to the overall low proportion of 'null' ALL; prior to the use of MoAb, such cases would probably have been classified as undifferentiated acute leukaemia or 'null' ALL. The search for B-cell-related markers showed that the incidence of pre-B-ALL cases (cytoplasmic immunoglobulin positive cases) was similar in adults and in children (25.6% and 32%, respectively). Furthermore, the great majority of cases studied expressed the BA-1 antigen (92.8% of adults and 79% of children), whilst the BA-2 antigen was found in 53% of cases (tested only in children), confirming a hierarchy in the expression of B-cell related markers in cALL: BA-1, BA-2, CyIg. Several of the 'null' cases also expressed the BA-1 antigen on a variable proportion of cells, pointing to a possible B-cell origin of the blasts. This multicentre study shows that both in adult and in childhood ALL the combined use of conventional immunological markers and of a panel of MoAb allows identification of the cell lineage of the great majority of cases, thus reducing the number of 'null' ALL. Furthermore, these findings suggest that practically all cases of ALL belong either to the T or to the B cell compartment and that the neoplastic cells appear blocked at different levels along the lymphoid differentiation pathway.

Acute Disease↗
PubMed1984

Lineage relationship of chronic lymphocytic leukemia and hairy cell leukemia: studies with TPA.

The tumor promoting agent TPA (phorbol ester; 1.6 X 10(-8)M) was used to induce the differentiation in vitro of B-chronic lymphocytic leukemia (B-CLL) cells from 14 untreated patients. The uninduced phenotype was SIg+, Mrbc+, RFT-1+, RFA-4-, FMC7-. After 72 h incubation with TPA, B-CLL cells became RFA-4+, FMC7+ and lost the capability of Mrbc rosetting. Large proportions of the "induced" cells also showed morphological and ultrastructural changes, such as undulating membranes and bleblike protusions and became strongly positive for tartrate resistant acid phosphatase (TRAP+) and also contained cytoplasmic immunoglobulins. These features are very similar to the features of hairy cell leukemia (HCL). These observations confirm previous clinical findings that B-CLL and HCL are related disorders of the B lineage. The development of "hairy" features in induced B-CLL and in HCL seems to be a malignancy-associated feature because the Mrbc+ normal B cells (B-CLL-equivalent cells) isolated from tonsil also develop TRAP positivity but no membrane aberrations.

B-Lymphocytes↗
PubMedDate not supplied

Xenotransplantation in immunosuppressed nude mice of human solid tumors and acute leukemias directly from patients or in vitro cell lines.

Athymic nude (nu/nu) mice are widely employed for the heterotransplantation of human tumor cell lines established in vitro and tumor cells directly grafted from patients. By contrast, hemopoietic malignancies have consistently proved difficult to transplant and well-characterized human leukemias suitable for studies in nude mice are scarce. We report here our experience with subcutaneous xenotransplantation of human neoplastic cells into nu/nu mice immunosuppressed through sublethal irradiation and splenectomy (SI-nu/nu) and with an additional injection of anti-Asialo-GM1 antibodies (SIA-nu/nu) in order to eliminate natural killer activity. Thirteen out of 16 continuous cell lines established in vitro from solid tumors and 7 out of 14 human tumors obtained from fragments of surgical specimens formed a progressively growing tumor in SI-nu/nu mice. Six out of 8 in vitro established human leukemic cell lines and 5 out of 18 neoplastic hematopoietic cells directly xenotransplanted from the patient grew SIA-nu/nu mice. When the membrane and chromosome markers of neoplastic cells that grew into the mice were evaluated, only marginal differences with those of the original tumors were found. In addition, when interfering factors alter the histological aspect of the primary tumor, xenotransplantation may also be of some help in histological diagnosis. By using SI- and SIA-nu/nu mice, it is thus possible to build up several new in vivo experimental systems with fresh human tumors that may be of value in studying the efficacy of differentiation factors and immunological maneuvers on the in vivo growth of human tumors.

Animals↗
PubMedDate not supplied

T lymphocyte subsets and colony growth in hairy-cell leukemia.

The distribution of T cell subsets and the T colony-forming capacity were assessed in 22 patients with hairy-cell leukemia. An overall increase in the proportion of T gamma cells (31 +/- 15%) and a decrease in Tmu cells (38 +/- 11%) were observed if compared with normal controls (16 +/- 6% for T gamma and 51 +/- 13% for Tmu). In half of the patients, however, these values were normal. T gamma cells were highest in the splenectomized patients and in the 15 non-splenectomized patients T gamma cells were higher in those with active disease. Patients with stable disease or in remission had values close to normal. The T colony-forming capacity of unseparated and enriched T lymphocytes was normal regardless of the T cell subset distribution and clinical stage of the disease. These findings suggest that in HCL, unlike B cell chronic lymphocytic leukemia, the imbalance in Tmu/T gamma ratio does not result in an impairment of the in vitro T colony-forming capacity.

Animals↗
PubMedDate not supplied

The patentability of living organisms between science, law and ethics.

The approval on May 1998 of the European Union (EU) directive on the legal protection of biotechnological inventions has aligned Europe to the international trend about the patenting of biotechnologies. Many questions are still unresolved, i.e. the differences between the article 53b of the European Patent Convention (EPC), which prohibits patenting of plants and animal varieties, whereas the directive states that Oinvention whose object are plants or animals may be patented if the practicability of the invention is not technically confined to a particular plant or animal varietyO (article 12). Again, the interpretation of plants or animal species specificity and that on the threatening public order and morality (which inhibits patenting) may have doubtful interpretations, according to the different EU States morality and law (e.g. Denmark does not admit patentability of transgenic animals). Despite difficulties, biotechnology Research and Development for applications to medicine, veterinary sciences, agriculture and foods is continuously growing. Bioethical independent evaluations of the applications of biotechnologies and of their side-effects (risk for biodiversity of plants and animals, safety of procedures to save mankind, respect of human dignity and of fundamental human rights, etc.) are mandatory to link the interests of science and industrial productions together with those of mankind. This is the original meaning given by van Potter to the word bioethics, as a bridge to the future.

Animal Population Groups↗
PubMedDate not supplied

Biotechnologies in haematological malignancies.

The last fifteen years have witnessed impressive changes in our approach to patients with different haematological malignancies. These have largely stemmed from the continuous development of biotechnologies and from their progressive implementation in the clinical setting. In this brief review, we will highlight some of the areas (diagnosis, follow-up and treatment) in which biotechnologies have had an objective impact and will also underline how a close biologico-clinical integration, unparalleled in all other fields of oncology, is today mandatory for an up-to-date management of haematological malignancies.

Antineoplastic Agents↗
PubMedDate not supplied

Oncology in the nineties: from genes to therapy.

Thanks to the impressive development and application of new sophisticated technologies, the last decade has offered remarkable advances in our understanding of the molecular and biological features of human neoplastic cells. DNA analysis in particular has contributed to the unravelling of some of the possible events which give rise to a transformed cell and which enable it to proliferate indiscriminately and to infiltrate. Cloning techniques which have allowed researchers to obtain and utilize purified molecules represent another milestone. This has opened the era of cytokines and growth factors, both in terms of their possible role in the establishment and/or progression of neoplastic conditions (autocrine/paracrine models) and of their use in clinical practice. Thus, growth factors such as granulocyte-macrophage colony stimulating factors (GM-CSF) and interleukin 3 (IL-3) are currently being employed in the management of cancer patients, mainly to support normal hemopoiesis. Conversely, recombinant interleukin 2 (IL-2) through its unique capacity to generate previously unrecognized cytotoxic activity, lymphokine active killer (LAK), has brought about new and more specific immunotherapeutic strategy. Further therapeutic possibilities will arise from the clinical use of monoclonal antibodies. Finally, the development of genetic engineering has opened the way to the early and revolutionary clinical exploitation of gene therapy; the possibility of utilizing in vivo anti-sense oligonucleotides in an attempt to block the action of specific genes is also being contemplated.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Transformation, Neoplastic↗
PubMedDate not supplied

IL-2 in the treatment of chronic myeloid leukemia after lymphoid blast crisis: a pilot study.

Five patients with lymphoid blastic transformation of chronic myeloid leukemia have been treated with IL2 associated with Vincristine (VCR) plus Prednisone (PDN). Our study indicates that IL2 may be employed in the management of this disease without excessive toxicity at the higher doses in hospitalized patients and at the lower doses as outpatients. Concerning the therapeutic efficacy, our preliminary results indicate that IL2 might be useful in enhancing the chemosensitivity of the leukemic blasts. It remains to be seen if this will result in a rapid return to the CP and in a prolongation of survival.

Adult↗