Scanning electron microscopy study of spinal cord nerve cells from chick embryos cultured in vitro with poly-L-lysine]

Chick embryo nerve cells from the lumbo-sacral spinal cord have been isolated by trypsinisation and cultivated in Rose chambers on polylysine-L as a substrate. The cells are analysed by scanning electron microscopy. The mode of adherence of these cells to the substrate and the modifications of the surface of the neuroblasts during their transformation into neurocytes are studied.     

Increase in serum testosterone in newborn rats]

The changes in serum testosterone and dihydrotestosterone concentrations have been measured in the newborn Rat, before, during and up to 6 hrs after birth. A sudden and transient increase of serum testosterone has been found between 0 and 2 hrs. At 4 hrs, the value returns to that found in the foetus at the end of gestation.     

In vitro differentiation of primitive molar tissue from mouse embryo]

The developing molar tissues of the lower jaw of 13, 14 and 15 day Mouse embryos were removed and cultured in vitro. Complete molar dentition differentiated.     

Evolution of myocardial glycolysis in perinatal rats]

Glycolysis was assessed in the Langendorff perfused rat heart during the perinatal period. Glucose uptake, lactate production, 14C-glucose incorporation into glycogen, tissue content content of glycogen, lactate and high energy phosphates were measured in the foetus of 21.5 days post co?tum and in the newborn of 1 and 7 days post partum. Glycogen synthesis and anaerobic glycolysis were found to be more active in the foetal heart and to decrease during the first neonatal week.     

Functional study of cultured bone cells]

Osseous cells in culture synthesize and excrete glycosaminoglycans, collagen and alkaline phosphatases, revealed by the classical histochemical reactions. Observation of the living cells iwth the polarizing microscope, after a five day-culture, reveals the presence of micro-crystals of mineral salts only at the level of cells and cellular groupings.     

Amino acid transport by small and large intestine of newborn pig

Summary Unidirectional fluxes of different amino acids have been determined across newborn pig small intestine and colon. The systems responsible for amino acid transport are present in the same proportion in both tissues. Colonic transport of amino acids appears to represent a transient overspill function of the small intestine.     

Differentiation of human megakaryocytes in culture starting from the primordial circulating cells in the newborn]

Human neonatal blood mononuclear cells were seeded in plasma clot containing high dose of a crude erythropietin. Pure megakaryocyte colonies were observed rarely and most of the colonies were mixed, megakaryocytes being located between subcolonies of erythrocytic bursts. The megakaryocytic nature of large cells could be clearly confirmed by the presence of platelet peroxidase, demarcation membranes, and alpha granules detected by electron microscopy; in addition mature micromegakaryocytes were recognized, shedding platelets.     

Changes of chromosome number in cells ofDrosophila melanogaster cultured in vitro

Riassunto Cellule embrionali diD. melanogaster, coltivate in vitro fino a 120 h, presentano un progressivo aumento delle variazioni dei numeri cromosomici interessanti principalmente il I e il IV paio di cromosomi.     

Demonstration of erythroblastic differentiation after 14 days in blood in vitro during Vaquez's disease without addition of erythropoietin]

Leucocytes of normal individuals and patients with polycythemia vera were isolated from the peripheral blood by Ficoll-Hipaque density gradient centrifugation and cultured in vitro suing the bovine plasma clot culture technique with a minor modification: the addition of fresh normal serum. After 14 days in the presence of sheep erythropo?etin (3U/ml) erythropo?etic bursts containing between 3 and 10 subcolonies were observed in normal and polycythemia vera cultures. Blood leucocytes of patients with polycythemia vera rise to these erythropo?etic bursts without addition of erythropo?etin to the culture. This behavior was never observed in the blood of normal individuals. These results indicate that in polycythemia vera commited erythro?d stem cells of high proliferative capacity closely resembling the murine erythro?d burst forming unit have an abnormal sensitivity to erythropo?etin as well as the immediate precursors of the proerythroblasts. The culture of these cells from the peripheral blood offers some practical advantages.     

Enhanced inhibition of RNA synthesis by amanitins in in vitro cultured cells

Summary The inhibition of RNA synthesis by -amanitin on vitro cultured cells is very slow. The action of various analogues of the toxin was tested and some of them proved more effective. Moreover pretreatment of cell cultures with DEAE-dextran greatly enhanced the effect of -amanitin.Acknowledgments. We thank ProfessorTh. Wieland and Dr.H. Faulstich (Max-Planck-Institut, Heidelberg) for the generous gift of amanitins. This investigation was supported by grant No. 74.00637.65 from C.N.R. (Roma).     

Ischemic myocardial injury in cultured heart cells: In situ lysosomal damage

Summary Primary cultures of rat myocardial cells which were subjected to oxygen and glucose deprivation, 2 conditions associated with ischemia, were evaluated for alterations in lysosomal integrity. A photometric technique measured changes in latent acid phosphatase activity and lysosomal membrane permeability.Acknowledgments: The authors thank Dora Fernandez for skillful technical assistance. Research was supported by a grant from the National Heart, Lung, and Blood Institute, HL 18647.     

Myosin isoenzymes during in vivo and in vitro differentiation of chick muscles

Muscle fibers differentiated, in vitro, from myoblasts of embryonic Pectoralis (presumptive fast) and embryonic Adductor magnus (presumptive slow) muscles synthesise the same type of myosin, which is identical to the type synthesised in day 10 embryonic muscles. This type of myosin comigrates with the third isozyme of the adult fast-twitch muscle. There is no change in the kind of myosin in cultures aged from 2 to 7 weeks, whereas during the in vivo differentiation of the same muscles, new isozymes appear which are different in the two muscles. With regard to myosin, the muscle fibers differentiated, in vitro, from myoblasts of fast or slow muscles expressed the same phenotype.     

Insulin action in cultured human skeletal muscle cells during differentiation: assessment of cell surface GLUT4 and GLUT1 content

In mature human skeletal muscle, insulin-stimulated glucose transport is mediated primarily via the GLUT4 glucose transporter. However, in contrast to mature skeletal muscle, cultured muscle expresses significant levels of the GLUT1 glucose transporter. To assess the relative contribution of these two glucose transporters, we used a novel photolabelling techniques to assess the cell surface abundance of GLUT1 and GLUT4 specifically in primary cultures of human skeletal muscle. We demonstrate that insulin-stimulated glucose transport in cultured human skeletal muscle is mediated by GLUT4, as no effect on GLUT1 appearance at the plasma membrane was noted. Furthermore, GLUT4 mRNA and protein increased twofold (p < 0.05), after differentiation, whereas GLUT1 mRNA and protein decreased 55% (p < 0.005). Incubation of differentiated human skeletal muscle cells with a non-peptide insulin mimetic significantly (p < 0.05) increased glucose uptake and glycogen synthesis. Thus, cultured myotubes are a useful tool to facilitate biological and molecular validation of novel pharmacological agents aimed to improve glucose metabolism in skeletal muscle.     

The differentiation ofCoptis plants in vitro from callus cultures

Zusammenfassung Kalluskulturen aus Petiolastücken vonCoptis japonica (Ranunculaceae) synthetisieren das Alkaloid Berberin. Unter geeigneten Bedingungen werden auf den Kallusstücken ganze Pflanzen herangebildet.

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Part XIII in the series Studies on Plant Tissue Cultures. Part XII, see reference³.