X-linked severe combined immunodeficiency (SCID-X1) is a recessive hereditary disorder in which early T and Natural Killer (NK) lymphocyte development is blocked. The genetic disorder results from mutations in the common gamma c chain that participates in several cytokine receptors including the interleukin-2 (Il-2), Il-4, Il-7, Il-9, Il-15 receptors. SCID-X1 offers a reliable model for gene therapy as it is a lethal condition that is, in many cases, curable by allogeneic bone marrow transplantation. We have shown that retrovirus-mediated transfer of the gamma c cDNA induced gamma c chain expression and restored the function of the high-affinity IL-2 receptor on SCI-X1 EBV-transformed B-cell lines. We have the designed culture conditions to study NK-cell and T-cell development of CD34+ hematopoietic progenitor cells. In the culture systems, gamma c transduced CD34+ marrow cells from two SCID-X1 patients were able to mature into CD56+ and/or CD16+ NK cells and into CD4+ TCR alpha beta+ T cells. These preclinical results set the basis for a clinical study of ex-vivo gamma c gene transfer into CD34+ cells from SCID-X1 patients.

The diagnosis and management of acute myeloid leukemia (AML) in the elderly is reviewed, including the basic aspects of epidemiology, cytogenetics, and prognostic factors. AML at higher ages is associated with several unique biologic and clinical characteristics. It generally arise from an early level of hematopoietic stem cells, and has a particularly high incidence of poor prognostic karyotypes. Effective treatment of the elderly patient with AML remains a challenging task. The importance of therapeutic approaches and promising new drugs is summarized. Prospective randomized studies clearly demonstrate that elderly patients benefit from intensive induction therapy. Hematopoietic growth factors accelerate the recovery from treatment-induced neutropenia and may improve the outcome. In patients not eligible for intensive chemotherapy, prospective studies testing different palliative or moderately intensive treatments are needed to improve quality of life and survival. New treatment strategies need to be developed to further improve on the therapeutic perspectives for elderly patients with AML.

Analysis of the legislation concerning xenotransplantation and constitution of stem cell banks reveals an absence of status common to embryos and animals. They do not have any legal status, they are not assimilated to objects, but benefit from protective measures. Xenotransplantation is regulated by a set of rules, while embryo research is currently prohibited in France, but is regulated in other countries. Bioethical legislation raises difficulties related to the early stage of its development and its perverse effects. The consultation process prior to defining legislation must take into account the international dimension and the necessary progress of scientific research.

Two types of epithelial cells derived from a unique embryonic stem cell coexist in the liver: hepatocytes, which form the liver parenchyma, and cholangiocytes which line intrahepatic bile ducts. Both cell types represent more than 70% and around 3% of hepatic cells, respectively. Initially secreted in the canalicular space formed by the apical domain of hepatocytes, bile is subsequently collected and modified in bile ducts. Both types of epithelia can regenerate as a result of differentiated cell proliferation. However, massive or chronic injury may induce the emergence and proliferation of oval cells, a heterogeneous population of small cells expressing embryonic markers that may subsequently differentiate into hepatocytes or cholangiocytes. Oval cells may also give rise to hepatocellular or cholangiocellular carcinomas. They may derive not only from hepatic cells (including hepatocytes and cholangiocytes themselves), but also from extrahepatic haematopoietic stem cells.

Our study is retrospective. We report the results of conventional chemotherapy ins previosly untreated patients with myeloma. Survival and prognostic factors were analysed in 109 patients diagnosed from 1983 to 1992. The median age was 65 years, 87 patients (80%) were including in the stage III according the Durie Salmon staging system. The median survival time was 27 months and 10 years survival rate is 3.66%. In the univariate analysis, two prognostic variables were retained namely the hemoglobin and creatinine level. The study suggest that conventional therapy is a good treatment for old patients. However, patients younger than 55 years, must benefit from intensive chemotherapy supported by autologous bone marrow, pheripheral blood stem cells, or allogenic bone marrow transplantation. A considerable encrace in duration of remission and survival is possible.

Four hematopoietic growth factors have marketing approval in France: filgrastime (G-CSF), malgraostime (GM-CSF), lenograstime (glycolysated G-CSF) and erythropoietin. A standards, options and recommendations document has not yet been established for erythropoietin which is excluded from this report. Administration of hematopoietic growth factors can be proposed in five clinical situations: primary prophylaxis, secondary prophylaxis, curative care, after myeloablative chemotherapy and hematopoietic stem cell grafting, and finally mobilization of peripheral stem cells. Primary prophylaxis: excepting therapeutic trials, the use of hematopoietic growth factors is recommended for clinical situations where a significant incidence of neutropenia with fever has been reported in randomized trials and in rare cases where there is an increased risk of severe infectious complications. Hematopoietic growth factors are indispensable for increasing the quality of cytapheresis peripheral stem cell harvesting.

A multicentric study involving 12 centers was made to investigate the results of peripheral stem cell collection carried out between 1996 and 1997 from 655 patients with hemopathic syndromes or malignant tumors, The aim of this investigation was to determine the predictive factors for transplant quality, and to thereby optimize collection procedures.

Frontotemporal dementia and Parkinsonism linked to chromosome 17 (FTDP-17) are related to pathogenic mutations of the Tau gene. One of these, located at codon 279, results in an asparagine to lysine substitution. It was detected in three unrelated families from different origins. This mutation affects splicing, allowing exon 10 to be incorporated more frequently in the Tau transcripts, causing an abnormal preponderance of three-over four-repeat isoforms in soluble tau and the presence of the four-repeat isoforms in the insoluble tau. To better understand this newly described pathology, we analysed data from the three previously reported families. The American family, described as "pallido-ponto-nigral degeneration" is a large family which has been extensively studied (13 neuropathological studies). The Japanese family was initially presented as "pallidonigroluysian degeneration with iron deposition" and recently found to be related to N279 K mutation. We reported clinical, pathological and genetic data from the French family. Clinical particularities are ocular movements alterations with vertical supranuclear palsy, extrapyramidal signs (rigidity, dyskinesia, with atypical resting and postural tremor) and progressive dementia. Partial or no L-DOPA responsiveness is noted. These features led to discuss progressive supranuclear palsy, in some cases. There is no amyotrophy, nor any sensibility to neuroleptics, both signs being observed in other FTDP-17 syndromes. Neuropathology and immunohistochemistry confirm the presence of Tau immunolabeled inclusions, affecting mainly neurons in brain stem nuclei and glial cells in supratentorial white matter. Neuronal loss, which is moderate in frontal and temporal cortex, is severe in substantia nigra and globus pallidum. It is variable in other subcortical structures. In these structures, it is associated with iron deposition. This latter may participate in the degenerative process of cells and led to death in some specific neurons. The selectivity of neuronal death in hereditary diseases, when compared to data concerning sporadic neurodegenerative diseases which share similar clinical signs and neuropathological lesions, reinforces the hypothesis of an increased vulnerability of some neuronal populations which express specific sets of tau isoforms. Neurons particularly involved in these diseases express exclusively exon 10 + tau isoforms.

Despite different therapeutic modalities (surgery, hormones therapy, chemotherapy), 5-year survival in patients with malignant adrenocortical carcinoma remains only 10% to 20%. Bone marrow grafts may be proposed to intensify treatment.

Myelodysplastic syndromes (MDS) are clonal disorders of pluripotent hematopoietic stem cells. MDS occur predominantly over the age of 60 years. The diagnosis of MDS is based on the examination of both blood films and bone marrow aspirate. Diseases such as vitamin B12 and/or folate deficiency, or cytotoxic therapy leading to a marrow dysplasia should be ruled out. Five subtypes are described in the FAB classification : refractory anaemia or refractory cytopenia, refractory sideroblastic anaemia, refractory anaemia with excess of blasts, refractory anaemia with excess of blasts in transformation, chronic myelomonocytic leukaemia. This FAB classification is based on a small number of parameters: percentage of blood and marrow blasts, percentage of ringed sideroblasts and blood monocytes. The anaemia is typically normo- or macrocytic, non regenerative, and in half cases is associated with neutropenia and/or thrombocytopenia. During blood film examination, cell abnormalities have to be notified, i.e. anisocytosis, poikilocytosis of red cells, morphological abnormalities of neutrophils including hypogranulation, hypolobulation, abnormal large platelets. The prognostic and the treatment of MDS depend on the subtype of the FAB classification, the patient's age, the percentage of marrow blasts, the importance of cytopenia, the presence or not of cytogenetic abnormalities and the existence or not of HLA-identical donor.

The association of osteogenic stem cells to a synthetic carrier makes possible the elaboration of bioartificial tissue. Numerous phosphocalcic ceramics does not trigger a foreign body reaction when implanted in bone tissue and thus, a number of materials are available osteogenic stem cell carriers to replace the bone tissue. Several methods can be used to harvest these cells. Their multiplication in vitro can lead to the appearance of anomalies of their metabolism or their karyotype. The culture method also seems to have a major influence on their appearance. The presence of these anomalies could explain the variability of results in terms of bone extracellular matrix synthesis after cell reimplantation. The surgical technique used for the implantation is also of influence. A method suppressing the in vitro period has been developed to avoid any cell metabolism modification. This method allows for a very reproducible bone synthesis in ectopic site. The availability of human embryonic stem cells could help to develop cell graft techniques for bone reconstruction.

In transfusion medicine, flow cytometry (FCM) is a methodology combining laser radiation, optics and a computerized treatment of numerous results. We can measure size, cellularity and fluorescence intensity of cells or particles in suspension after the binding of appropriate fluorescent antibodies or fluorescent dyes. The main utilisation of FCM in transfusion medicine is for quality control of the process of leukocyte reduction in red cell concentrates or in platelet units, using commercial kits. In addition, it is used for the enumeration of CD 34 positive cells before bone marrow transplantation and for control of platelet function in platelet units. For clinical investigations, FCM may be used for red cell phenotyping, essentially to detect minor populations (chimerism), for the estimation of red cell survival, or for the detection of fetal erythrocytes. In the field of platelet immunology, FCM is an essential tool for detecting platelet antibodies (auto or allo), for platelet phenotyping or for cross-matching. In the future perhaps, FCM will permit us to detect bacterial contamination or prion protein in transfused blood cells.

In the adult liver, the plasma membrane Liver Regulating Protein (LRP) has been found to participate in the recognition signals between hepatocytes and rat liver epithelial cells (RLECs) and to play a critical role in the functional stability of hepatocytes. Here, we report the involvement of LRP in hematopoiesis. First, LRP was evidenced in the hematopoietic fetal rat liver and in adult rat bone marrow. Then, the involvement of LRP in adult rat and human hematopoiesis was investigated in coculture of hematopoietic cells with RLECs. In the rat, RLECs sustain long-term production of hematopoietic cells and committed progenitors as well as bone marrow stroma cells. These effects can be specifically blocked by addition of anti-LRP antibodies to both culture systems. The supportive activity of RLECs on human hematopoiesis was assessed by comparison to the reference MS-5 cell line from both unifractioned and purified CD34(+)CD38(-) hematopoietic cells. Taken together, our results argue for the involvement of LRP in heterotypic interaction signals mediated by RLEC and bone marrow stromal cells which lead to hematopoietic primitive progenitors development. They might lead to interesting applications in fundamental research, pharmacology and therapeutics.

61 autologous transplantations for haematological malignancies have been performed with peripheral blood stem cells in 60 patients. 26 grafts were performed for non-Hodgkin's lymphoma (18 patients were transplanted in first remission, 8 patients after progression or relapse), 13 for multiple myeloma, 7 for Hodgkin's disease and 10 for acute myeloid leukaemia. One patient died from thrombosis of the portal vein. 38 patients were in complete remission 29 months (extremes: 14-44) after transplantation. 21 of 60 patients progressed or relapsed after transplantation, and 14 died. No death was attributed to graft failure, infection or haemorrhage. In conclusion, transplantation with peripheral blood stem cells is well tolerated, has a low toxicity rate, and can be used safely for patients with haematological malignancies.

119 collections of peripheral blood stem cells were performed in 60 patients suffering from various haematological malignancies. One patient was transplanted twice. Peripheral blood stem cell mobilisation was performed using various regimens. A correlation (r = 0.732) was found between the number of peripheral CD34+ cells and the number of CD34+ cells that were collected by apheresis. Furthermore, the number of collected peripheral blood stem cells correlated with the number of colony-forming units (CFU-GM) identified after cell culture (r = 0.607). After transplantation, the duration of neutropenia (> 0.5 x 10(9)/l) was 11.7 days (SD = 3.3) and of thrombocytopenia (> 20 x 10(9)/l) 12.7 days (SD = 6.8). For the whole group, no correlation was observed between the number of CD34+ cells infused and the length of the aplasia. However, when the patients were separated into two groups, according to the amount of CD34+ cells transplanted (< 10 x 10(6)/kg, n = 48 and > 10 x 10(6)/kg, n = 13), a statistically significant but moderate decrease in the duration of neutropenia and thrombocytopenia was observed in patients who received the highest doses of CD34+ cells. Our results confirm the utility of measuring the number of the CD34+ cells in peripheral blood as well as in the product collected by apheresis, but they challenge the place of cultures of progenitor haematopoietic cells. Moreover, the infusion of large amounts of CD34+ cells shortens the duration of the aplasia.

OSTEOLYSIS AND HYPERCALCEMIA: Multiple myeloma is a type B high-grade lymphoproliferative syndrome with bone tropism. Bone-related manifestations--osteolysis and hypercalcemia--are observed in 80 and 30% of cases respectively. Excessive bone resorption subsequent to destruction of the bone matrix by osteoclasts is associated with insufficient bone formation. This process plays a determining role in the development of osteolysis and hypercalcemia in multiple myeloma patients. MECHANISM OF BONE DESTRUCTION: The reality and intensity of bone destruction is clearly demonstrated by histomorphometric studies and more recently by biochemical methods using markers of bone resorption. The excessive bone resorption results from complex interactions between tumor plasma cells, bone cells, and stem cells and involves local factors and adhesion molecules. BISPHOSPHONATES: Bisphosphonates are powerful inhibitors of bone resorption. They constitute a substantial advance in the management of bone manifestation in patients with multiple myeloma. Bisphosphonates not only have a well-established curative effect in patients with tumor-induced hypercalcemia, but also inhibit disease progression in bone.