In this paper, it has been shown that human placental tissular extracts are a potent source of natural haemopoietic growth factors. The colony-stimulating activities (CSA) recovered by extraction from washed placental pulp were active both on human and murine haemopoietic progenitors, from monocytic and granulocytic lineages. Crude tissular extracts contained CSA titers at least ten fold the titers usually found in placenta culture media. Placenta is the only human tissue easily available for the study of natural tissue-bound haemopoietic regulators. Extraction on an industrial scale, as proposed for the first time in this paper, should also benefit the identification and purification of new minor molecular classes of growth and maturation factors or inhibitors involved in human haemopoiesis.

INTRODUCTION. Aging--the effect of time--occurs in every living organism. Senescence is the last period of the lifespan, leading to death. It happens in all animals, with the exception of a few didermic species (Hydras) having a stock of embryonic cells and being immortal. The causes of animal senescence are badly known. They depend both on genetic characters (maximal lifespan of a species) and on medium factors (mean expectation of life of the animals of a species). Animal senescence could depend on cell aging: 1) by senescence and death of the differentiated cells, 2) by modified proliferation and differentiation of the stem cells of differentiated tissues, 3) by alterations in the extracellular matrices, 4) by interactions between factors 1) 2) and 3) in each tissue, 5) by interactions between the several tissues of an organism. This complexity badly impedes the experimental study of animal senescence. Normal mammal cells are aging when they are cultivated (in vitro ageing): their phenotype varies and depends on the cell generation (in vitro differentiation); the last cell-generation doesn't divide anymore and declines until death of the culture (in vitro senescence). Analysis of these artificial but well controlled systems allows an experimental approach of the proliferation, differentiation, senescence and death of the cells and of the extracellular matrix functions. Present literature upon in vitro aging of cultivated human cells is essentially made of papers where proliferation and differentiation characteristics are compared between early ("young") and late ("old") cell-generations of the cultures. FIBROBLASTIC CELLS OF THE MOUSE SKIN. This cell type has been studied in our laboratory, using different systems: 1) Primary cultures isolated from peeled skins of 19 day old mouse embryos, 2) Mouse dermis analyzed in the animals, 3) Cultivated explants of skins, 4) Serial sub-cultures of fibroblasts isolated from these explants, 5) Cells cultivated comparably on plane substrates (glass, plastic, collagen films) and on tridimensional matrices (collagen fibres). Systems 2), 3), 4) and 5) have been obtained either from 19 day old embryos or from 6 groups of animals of different ages (from 1/2 till 25 month). In primary cultures (system 1) all the cell generations have been analyzed, including the last one until death of the culture. We have shown that many characters are varying with cell-generation: cell form and cell mass, rate of DNA replication and cell division, rate of RNA transcription, nature of the accumulated and of the synthetized proteins, organization of the cytoskeletal elements, organization of the extracellular matrix, type of cell death.(ABSTRACT TRUNCATED AT 400 WORDS)

In vitro clonal growth of tumour cells may reflect biological properties of cancer and thus have prognostic value. This study seeks to establish correlations between the clinical outcome in patients after surgery for colorectal cancer and clonal growth of their tumours. History, status and follow-up data are collected. Tumour samples taken at operation under sterile conditions are plated immediately in our methylcellulose clonal assay system. Out of 65 consecutive samples, 3 did not yield sufficient cells for culture. Thirty-four (55%) grew more than 0.3 colonies/10(5) cells seeded; cloning efficiency was greater than 10 colonies/10(5) cells in 19. The 28 (45%) failures included 3 benign polyps cultured; 7 samples had visible bacterial or fungal contamination. The other 18 negative cultures may be due to cytotoxicity of the antibiotics or heterogeneity of tumour cells. These preliminary results show that colorectal cancers grow well in vitro in the absence of restricting factors, but they do not confirm the hypothesis that proliferative potential and differentiation are opposing processes. Location of the tumour may play a role, since best growth was seen in tumours of the caecum and terminal colon.

Blood-derived hemopoietic stem cells were collected using a continuous (10 patients) or a semi-continuous flow separator (2 patients) in some patients with acute non-lymphocytic leukemia. For ten out of those patients, five to seven leukaphereses were performed during a short period (median = 11 days) of marrow recovery following severe aplasia induced by an intensive chemotherapy. The mean number of CFU-GM cells collected per leukapheresis and per patient respectively was 6.7 X 10(4)/kg and 38.5 X 10(4)/kg. This latter number was similar to that obtained during a marrow harvest performed for a bone marrow transplantation, suggesting that high numbers of hemopoietic stem cells can be collected from the peripheral blood in leukemic patients and used for autologous transplantation.

Tissue hypoxia is the main stimulus of erythropoietin production. Erythropoietin stimulates erythropoiesis by acting on medullary stem cells. Unlike healthy subjects adjusting to high altitude, patients with chronic respiratory failure do not always develop polycythaemia. In those who do, the physiopathology of polycythaemia remains unknown. It seems to be due to insufficient action more than to insufficient production of erythropoietin. Most authors agree that polycythaemia is harmful when the haematocrit exceeds 60%. The most commonly used corrective method nowadays is phlebotomy. Blood withdrawal is effective on clinical symptoms and on pulmonary arterial hypertension, but not on blood gases and ventilatory parameters at rest or during exercise.

The present paper describes the theory and practice of cell/particle electrophoresis: the migration of cells/particles free to move in suspension under the influence of an applied electrical field, without any undue damage of cell membranes. The technique is quite different from high voltage electrophoresis on gels and paper. The quantitative biophysical parameter, never likely to be zero, is the electrophoretic mobility, experimentally determined by the cell electrophoresis apparatus, and mathematically related to the electrokinetic or the zeta potential. A detailed description of the analytical and preparative electrophoresis is given. Data are presented on the electrophoretic properties of bone tissue cells and cells of the immune system.

Passive, active and adoptive immunotherapy of human cancers and leukemias raise a renewed interest strengthened by the availability of purified biological substances such as IL2, interferon, thymic hormones and by some recent favourable therapeutic results which have demonstrated the possibility of obtaining objective tumor regressions by immunotherapy. Analysis of results of chemotherapy shows that only 8 human cancers and malignant hemopathies are curable at an advanced diffuse stage of disease. These cancers are characterized by the rarity or absence of late metastases (more than 3-4 years after initial diagnosis). Cure may be considered as complete with a high probability if disease free status is maintained for 3 years. This finding suggests the absence of tumor stem cells capable to produce late metastases. Other cancers are not chemocurable at an advanced systemic stage. In most of them late metastases (greater than 4 years after diagnosis) are observed. A model of organization of malignant tumors based on the distinction between primitive tumor stem cells which are rarely or exceptionally in cycle and protected by a specific microenvironment and committed tumor stem cells is proposed. According to this model, only cancers and/or metastases and malignant hemopathies containing but committed tumor stem cells would be chemocurable. Analysis of a trial of adjuvant therapy of breast cancer with poly A: poly U shows the possibility of immunotherapy to prevent the development of late metastases, independently of hormonal status in contrast with standard adjuvant chemotherapy which is only active on early micrometastases in premenopausal women.(ABSTRACT TRUNCATED AT 250 WORDS)

Histo-monocytes are cells playing an important role in host defense reaction and purification of the organism. These cells belong to a new system of highly phagocytic mononuclear cells termed "mononuclear phagocyte system". This system includes the promonocytes and their precursors in the bone marrow, the monocytes in the peripheral blood and the different types of histiocytes and macrophages particularly Kupffer cells. Histiocytes can also transform into epithelioid cells and giant cells. The inclusion of all these cells in this system is based on similarities in the morphology, function, origin and kinetics of the phagocytes. The most important morphologic characteristics of these cells are described. It is also shown that the mononuclear phagocytic system is a secretory system. The different types of products are described. Recently, so-called accessory cells of the immunity were described, comprising dendritic reticular cells from the follicles and interdigitating reticular cells from the deep cortical zone of the lymph node. Those cells belong both probably to the system. The cells of this system are engaged in the clearance of multiple organs, in the inflammatory process, in the immune response and in the immune surveillance against tumor.

Immune serum and spleen cells from mice vaccinated with a cell-wall fraction (PG) from Brucella were previously shown to transfer a good protection to mice against a virulent Brucella challenge. This protection estimated by spleen and liver time-course infection was similar to that afforded by vaccination. In present experiments, DBA/2 mice were first transferred with either immune serum from infected mice, splenic cells from mice intravenously vaccinated with PG fraction 28 days previously, or both immune serum and splenic cells. In this case, the serum was either injected before the challenge, as were the splenic cells, or 2 days after it in order to reduce the lowering effect of the serum on level of initial colonization of the spleen. The transferred mice were then intravenously challenged with the virulent strain B. abortus 544 and liver and spleen counts were performed on groups of five mice weekly up to six weeks. Immune serum and splenic cells from vaccinated mice were again shown to strongly reduce the time-course of splenic infection. However addition of both effects was observed for a short time only two and three weeks post-challenge and only when the serum was injected after the challenge. In contrast, no additive or even an antagonistic effect was observed after the 21st day. Liver infection was not notably modified by both immune serum or splenic cells (except increment of initial colonisation by serum) until the 21st day when both helped reduce the course of infection. However again no additive effect was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

In cultures of normal mouse hematopoietic cells containing mast cell growth factor develop cells with many features of mast cells. These cells seem heterogeneous with respect to size, cell surface, granules maturity and morphology of nucleus using transmission and scanning electron microscopy. Alcian blue-safranin staining shows that most of the proteoglycan synthesized by cultured mast cells is weakly sulfated and non heparin-mucopolysaccharides. These results support the view that cultured mast cells resemble to mucosal mast cells, and are clearly different from serosal mast cells.

Two methods of analytical microscopy have been used to study the distribution of aluminum in bone marrow of rats intoxicated by aluminum gluconate. Images of the distribution of aluminum in a field of 250 microns in diameter were obtained by analytical ion microscopy. They show that this element was concentrated in spots, associated with iron or alone, in the cytoplasm of some cells. Electron Probe Microanalysis (EPMA) has shown that aluminum concentration occurred in cells of the reticulo-endothelial system, principally in the reticular cells of erythroblastic islets. In cells of the reticuloendothelial system, aluminum was observed in intracytoplasmic organelles having ultrastructural characteristics of lysosomes or phagolysosomes. In these organelles, aluminum is always associated with phosphorus and sometimes with iron. No cytoplasmic or nuclear aluminum accumulation was detected in any other variety of bone marrow cells. The consequences of the selective accumulation of aluminum in the cytoplasm of reticular cells of erythroblastic islets for the maturation of erythrocytes are discussed.

The level of circulating myeloid progenitor cells (CFU-G), considered to be a good index of the quantity of circulating hemopoietic stem cells, was measured in the peripheral blood of 5 patients with acute leukemia as they entered first remission. High levels of circulating CFU-G were found in 4 of these 5 patients, depending on the intensity and the number of courses of induction chemotherapy. Repeated cytaphereses were done on 3 of these patients in order to collect and to cryopreserve circulating stem cells, to be used later for autologous transplantation. We propose a model which calculates the number of cytaphereses sufficient to obtain a level of 10(5) CFU-G/kg of weight, considered necessary to achieve a good hemopoietic reconstitution after transplantation.

Attempts at in vitro fertilization can fail at two points: during the fertilization itself or during embryo transfer. In the case of implantation failures, two causes can be invoked: the condition of the endometrium and the quality of the embryo. It can be assumed that after ovarian stimulation or after the loss of large quantities of follicular fluid during oocyte recovery, the postovulatory phase, and consequently the condition of the endometrium, may be atypical, or that the synchronism and the menstrual cycle is no longer perfect. To date, experimental, biochemical, and morphological observations have not confirmed this hypothesis. The condition of the embryo appears to be the predominant factor. The criteria for evaluating its quality are not all perfectly objective. Those which are truly objective are obtained a posteriori by invasive methods after the death of the embryo, the other criteria, obtained with the living embryo, entail a certain element of subjectivity. Non-invasive methods: By observation, the size and form of the embryo can be evaluated, as well as the equality of blastomere size, the presence or absence of anuclear cellular fragments, the number of nuclei per blastomere, the granular or clear appearance of the egg or the blastomeres, and the appearance of the cumulus. The rate of development is an important criterion: the best chances for pregnancy are obtained when the 2-pronuclei stage occurs no later than 20 h, after insemination, the 2-blastomere stage no later than 35 h., and the 4-blastomere stage no later than 45 h. Invasive methods: The intensity of fluorescence using fluorescein diacetate. Karyotype containing numerous chromosome anomalies.(ABSTRACT TRUNCATED AT 250 WORDS)

The authors report their experience with the ASTA Z 7557, a derivative of cyclophosphamide, for the in vitro treatment of leukemic bone marrows. They determined the sensitivity of human leukemic progenitors (CFU-L, n = 9) and normal progenitors studied in semi-solid media cultures (CFU-GM, n = 37; BFU-e, n = 11) and in long term marrow culture (pré-CFU-GM n = 41). Data establish: The inhibition of the in vitro proliferation of CFU-L by ASTA Z 7557. The similar sensitivity of CFU-L and normal CFU-GM. The respect, at doses toxic on CFU-L and CFU-GM, of more primitive stem cells, capable of self-renewing and the existence of correlation between the intensiveness of treatment and the regeneration capacity of CFU-GM; therefore, they defined a maximum tolerable dose which spares 5 +/- 5% CFU-GM (DL 95) after treatment. The existence of a wide range susceptibility from patient to patient which requires the determination of the DL 95 for each individual patient.

The fibroblast, major cell of connective tissue, secretes the various elements of interstitium: collagens, proelastin, glycoproteins and proteoglycans. It maintains the turnover of these structures and intervenes, also, in the cholesterol LDL metabolism. These various properties explains its different morphological aspects. In young patients, it is an active secretory cell. Its voluminous cytoplasm contains a well developed endoplasmic reticulum and others organelles. It is always in close connection with collagen fibers. The cytoskeleton consists of a fine network visible throughout the cytoplasm and near of secretory areas. In adult patients, the fibroblast keeps the same characteristics, but the endoplasmic reticulum is poorer than in young subjects. In old patients (physiologic or pathologic ageing) it becomes a quiescent cell. It is a flattened cell; its cytoplasm contains a poorly developed endoplasmic reticulum and numerous dense bodies. Its cytoskeleton is characterized by voluminous fascicles or bundles of microfilaments into large cytoplasmic areas. This modified fibroblast has not direct contact with collagen. In all cases, various stimuli can: activate the fibroblast. Then this cell becomes a large cell with very abundant reticulum endoplasmic, ribosomes, polysomes, and numerous secretory vesicles. It is an active secreting cell; becomes fibroblast and; change into myofibroblast by presence of myofilaments in its cytoplasm.

Some hormonal factors, possibly involved in the proliferation and differentiation of adipose precursor cells in vivo, have been characterized in vitro using different preadipocyte cell lines established from rodent adipose tissue. The process of adipose conversion has also been studied using these cell lines; in this process, stem cells (adipoblasts) were committed at any cell division during the growth phase. At confluence, committed cells (preadipocytes) underwent a limited number of mitoses and differentiated into adipose cells, whereas the uncommitted cells remained as stem cells in the cell population. This stochastic model could be extended to the development of rat adipose tissue in vivo. The study of adipose conversion showed the early emergence of lipoprotein lipase (LPL) and monoglyceride lipase (MGL). LPL activity appeared in the cells before any triglyceride accumulation. In contrast, this accumulation seemed dependent upon the emergence of glycerol-3-phosphate dehydrogenase. In vitro experiments clearly established that LPL-containing (differentiating) cells underwent postconfluent mitoses. This limited proliferation was in agreement with previous data obtained in vivo and indicates that only triglyceride-containing (mature) cells could not divide.