[Localization of alpha fetoprotein in neuroepithelial derivatives of murine teratocarcinomas].
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Aging↗
Biomedical subjects
J Uriel
Publications and source records attributed to J Uriel.
[Accumulation of radiolabeled alpha fetoprotein in spontaneous mammary tumors in mice].
Radiolabelled alphafetoprotein (AFP) was selectively concentrated by spontaneous mammary carcinomas of the Mouse. External photoscans of Mice injected with 131I-AFP confirmed the significant accumulation of the protein in the tumors. These results prove the usefulness of AFP as a radiotracer for mammary carcinomas and represent a novel approach for tumor detection.
Adenocarcinoma↗
The enzymatic mechanism of the otospongiotic disease and NaF action on the enzymatic balance.
Extensive research on enzymes led to the discovery of the innermost mechanism of the otospongiotic disease. The authors present the results of multiple correlations made from February 1976 to September 1980 on 648 samples of perilymph taken during stapedectomies performed on otosclerotic patients. We studied microdosages of three selected enzymes--trypsin, alpha 1 antitrypsin, and alpha 2 macroglobulin--in each of the samples and their relationship with cochlear deterioration expressed in dBs of bone conduction decrease in pure-tone audiometry testing. This study allowed us a better knowledge of the enzymatic mechanism of the otospongiotic disease, based on the previously reported trypsin-alpha 1 antitrypsin balance, but in which alpha 2 macroglobulin appears to play a role as essential as that of alpha 1 antitrypsin. This enzymatic mechanism explains NaF efficiency, which is due in fact to a double action: not only direct trypsin inhibition, but also an overall reduction in enzymatic values in the perilymph of otospongiotic/otosclerotic patients. Current studies could lead to the possibility of future NaF replacement by proteinase inhibitors either of microbial origin, under study by Japanese researchers, or even of synthetic origin, which should be investigated. In fact, the role of NaF therapy could already be taken over by diphosphonates currently under study.
Audiometry, Pure-Tone↗
Intracellular alpha-fetoprotein and albumin in the developing nervous system of the baboon.
The intracellular presence of alpha-fetoprotein (AFP) and of albumin in the brain and other neural derivatives of three Baboon fetuses (9,13 and 17 weeks of gestational age, respectively), was demonstrated by immunocytochemical techniques. The largest localization of both proteins was observed in the 9 week old fetus, where most neural tube and neural crest derivatives showed intracytoplasmic labelling. The staining decreased abruptly in the 17 week old fetus. In the brain, of the youngest fetus examined, the penetration of AFP and albumin into the cerebral wall is transependymal. The route seems to possess differential activity since IgG molecules never appeared internalized in spite of their presence, like AFP and albumin, in the choroid plexus and the ventricular spaces of this fetus. It is also worth noting that the labelling declines as myelination and glial cell development progress. The wide distribution of AFP and albumin labelling supports the conclusion that the intracellular uptake of these proteins is probably general in immature nervous structures. Attention is brought to the binding and transport of polyunsaturated fatty acids by AFP and albumin as a possible explanation for the transitory presence of these proteins in the developing nervous system.
Albumins↗
Immunocytochemical localisation of alpha-fetoprotein (AFP) and serum albumin (ALB) in ecto-, meso- and endodermal tissue derivatives of the developing rat.
Recent work has provided evidence of the intracellular presence of AFP and serum albumin (ALB) in the central nervous system of rats, mice and primates. We report here the immunocytochemical localization of these proteins in tissue derivatives of the three germ layers (with the exclusion of nervous system components) during rat fetal and neonatal development. Positive labelling for AFP and ALB was transitorily observed in all tissue derivatives examined. For example, labelling for AFP in the epidermis started around the 16th day of fetal life and localized in some cell aggregations of the peridermis. Between the 17th and the 19th day AFP positive cells were observed in the basal layer of epidermis, while the stratum germinativum was always negative. The maximum intensity of labelling was at birth. At this time, AFP positive cells were visible in the strata spinosum, granulosum and corneum. On day 6 to 8 after birth, the labelling become negative. The localisation of ALB showed a similar pattern with the only difference of a short (2 to 5 days) displacement in time. It can be concluded that the intracellular uptake of AFP in the structures studied is transitory and follows the stage of cell and tissue differentiation. Relative to AFP, labelling for ALB seems to correspond to a more advanced stage of morphologic development.
Animals↗
Subcellular immunolocalization of alphafetoprotein (AFP) in cell lines established from Morris hepatoma 7777 and 8994. Lack of effect of dexamethasone on the ultrastructural detection of AFP in the 8994 cells.
The subcellular localization of alphafetoprotein (AFP) has been studied in two cell lines (McA-RH 7777 and McA-RH 8994) derived from Morris hepatomas 7777 and 8994, using immunoperoxidase labelling techniques. After fixation of the cells in a low concentration of glutaraldehyde, a hot saponin treatment was used to increase the permeability of their membranes without destroying their morphology. The perinuclear spaces, the lamellae of the endoplasmic reticulum and the saccules of the Golgi apparatus contain electron-dense precipitates; 90% of the 7777 cells and 55% of the 8994 cells in exponential phase of growth are AFP-positive. Dexamethasone, a synthetic glucocorticoid, increases AFP production by the 8994 cells without raising the number of AFP-positive cells.
Animals↗
Immunocytochemical demonstration of alpha-fetoprotein uptake by primary cultures of fetal hemisphere cells from mouse brain.
Mouse alpha-fetoprotein (AFP) was added for 24 h to primary cultures of mechanically dissociated mouse brain fetal hemisphere cells grown in a serum-free medium. The intracellular presence of AFP could be demonstrated by immunocytochemical methods mainly in the cytoplasm of numerous differentiating neurons. The staining occurred only after 6 days in culture. The whole network of neurites, straight processes and filaments also appeared positively labeled. No AFP was noticeable in control cultures grown in the absence of the protein.
Animals↗
Maternal serum levels of sex steroid-binding protein during pregnancy.
Serum concentrations of sex steroid-binding protein (SBP) were measured by an immunodiffusion technique in a total of 133 samples from 70 healthy pregnant women, 18 puerperal women and 21 non-pregnant women. In 6 individuals, trends or serum SBP were established from multiple samples taken throughout pregnancy. Maternal serum SBP levels had increased significantly above base line values as early as by 10 weeks gestation, and attained a plateau between 25 and 30 weeks, at which time mean values were about 10-fold higher than the normal non-pregnant range, the levels then declined slightly towards term. Parallel measurements of dihydrotestosterone-binding capacity of SBP showed a good correlation between SBP content and biological activity. Six abnormal pregnancies were encountered in the present study, and in five of them the molar ratios of bound hormone to SBP concentration were much lower than the normal value, suggesting a reduced binding capacity of the protein for the hormone.
Adult↗
[Enzymatic mechanism of otosclerosis. Action of NaF].
The authors present the conclusions they reached after more than four years of multiple correlations made from february 1976 to september 1980. 648 perilymph samples were selected from a total number of 811 samples taken during stapedectomies on otosclerotic patients. These multiple correlations were based on micro-dosages of three selected enzymes (trypsin-alpha 1 antitrypsin and alpha 2 macroglobulin, the fourth cathepsin B having not been found, even in perilymph pools) in each of the selected samples, and on their relationship with the cochlear deterioration expressed in dBs of B.C. decrease and in audiometric stages corrected with reference to the patients' age. This study leads to an enzymatic mechanism, based on the previously reported trypsin-alpha 1 antitrypsin balance, but in which alpha 2 macroglobulin appears to play as essential a role as that of alpha 1 A. This enzymatic mechanism explains NaF efficiency, due in fact to a double action, not only to direct trypsin inhibition, but also to an overall reduction in enzymatic levels in the perilymph of otosclerotic patients. The authors conclude by suggesting the possibility of future NaF replacement by proteinase inhibitors, either of microbial origin currently under study by Japanese researchers, or even of synthetic origin.
Adult↗
Localisation of alphafetoprotein (AFP) in murine teratocarcinoma.
Solid tumours with histopathological characteristics of teratocarcinoma (generally presenting the structures of nervous origin) were induced in the mouse by subcutaneous inoculation with murine embryonal carcinoma (EC) cells of line PCC4-azal. An indirect immunoperoxidase technique using anti-mouse AFP antibodies was applied for the localization of the protein on paraffin sections of tissue fixed with acetic acid-ethanol. The PCC4-azal EC cells were AFP negative in vitro. In the solid tumours, the immature embryonal or fetal components (i. e. tubes or cysts mimicking the development of the neural tube) and the groups of neuroepithelial cells arranged in more or less differentiating structures (pseudotubes, cluters) were AFP positive; on the contrary, cells of the same differentiated neuroepithelial type, but lacking recognizable tissue architecture, were AFP negative. Mature, adult components were AFP negative. Undifferentiated cancer components, whether structured or not, were AFP negative. These results suggest that the intracellular presence of AFP requires a minimum degree of both cell differentiation and tissue organization.
Animals↗
Early localization of alpha-fetoprotein in the developing nervous system of the chicken.
The intracellular presence of alpha-fetoprotein (AFP) and serum albumin (SA) has been recently demonstrated in the developing brain of primates, rats and mice. We report here the morphologic localization by immunocytochemical methods of AFP, SA, ovalbumin (OA) and immunoglobulin G (IgG) in the nervous system of chicken embryos. AFP was detected inside cells of the neural crest as soon as 48 hours after fertilization. Subsequently, the protein could be localized in many other neural structures, including cerebral cortex, brain stem nuclei, sensory retina, spinal cord and dorsal root ganglia. Disappearance of AFP inside the nervous system was observed 15 to 17 days after fertilization. The localization pattern of SA was similar to that of AFP, with the only difference being a short (2 to 3 days) displacement in time. On the contrary, OA and IgG were not found in the developing nervous system throughout the period examined. This provides support to the selectivity of the neural internalization of AFP and SA, and seems to exclude a mechanism of passive diffusion to explain such incorporation.
Animals↗
Coordinate secretion of mouse alphafetoprotein, mouse albumin and rat albumin by mouse hepatoma-rat hepatoma hybrid cells.
Mouse heptoma cells that secrete large amounts of alpha-fetoprotein (AFP) and albumin have been crossed with rat hepatoma cells that secret only albumin, and in relatively small amounts, to investigate the influence of each parental genome upon the expression of serum proteins. All of the ten independent hybrid clones examined produce mouse AFP and both mouse and rat albumin; none produces rat AFP. The absence of production of rat AFP by the hybrids suggests that different mechanisms are involved in the initiation and in the maintenance of expression of this function. The secretion of the three proteins by the hybrid cells is coordinate: Whatever the growth phase (exponential or stationary) and irrespective of the amounts produced over a wide range, the ratio secreted of mouse AFP to mouse albumin is near to one, and that of mouse albumin to rat albumin is near to five. In addition, even though the pattern of protein secretion during the growth cycle of hybrid cells is different from those of both parents, the products of both parental genomes conform to the new hybrid pattern. Finally, some hybrids secrete less of the proteins with increasing numbers of cell generations, yet all three continue to be secreted in coordinate fashion. Since the rates of secretion of serum proteins probably reflect their rates of synthesis, we conclude that coordinate secretion indicates coordinate synthesis, and may reflect coordinate transcription of the relevant genes.
Albumins↗
Immunocytochemical localization of alpha-fetoprotein in the developing rat brain.
The immunocytochemical localization of the alpha-fetoprotein (AFP), serum albumin (ALB), transferrin (Tf) and immunoglobulins (IgG) in developing rat brain has been studied by the indirect peroxidase technique using rabbit antibodies to AFP, ALB, Tf and IgG followed by goat anti-rabbit immunoglobulins conjugated with peroxidase. Evidence of a high selective staining for AFP and ALB is presented. The pattern of morphological localization of both proteins was similar throughout fetal and post-natal development up to 20-25 days of age. Large areas and groups of cells in all regions of the brain from the olfactory bulb to the medulla oblongata appeared positively stained at a given moment in the development. The labeling was cytoplasmic and, in the neuronal elements, extended to their axonic and dentritic prolongations. The intracellular localization of AFP and ALB in the developing rat brain may be related to the binding affinity of these proteins for oestrogens and/or essential fatty acids. The morphological data presented here suggest that both proteins are actively involved in the uptake of such substances by the cellular structures of the brain.
Aging↗
[Intracellular localization of alpha-fetoprotein and serum albumin in the central nervous system of the rat during fetal and postnatal development].
The morphological localisation of alphafetoprotein (AFP), serumalbumin (SA), transferrin and immunoglobulins (IgG) has been studied in the developing central nervous system of the Rat by immunocytochemical methods. Evidence is presented of a highly selective staining for AFP and SA, both proteins exhibiting the same topographical distribution. Practically all the areas of the brain and the spinal cord are stained at a given moment of the developmental process. The labeling is cytoplasmic and in the neuronal elements extends to their axonic and dendritic prolongations. The localization of AFP and SA in the nervous system may be related to the well known binding properties of these proteins for varied substances (estrogen and/or fatty acids). The morphological data presented here suggest that both proteins may be actively involved in the uptake of such substances by the cellular structures of the nervous tissue.
Aging↗
[Fixation of polyunsaturated fatty acids by alpha fetoprotein and serum albumin in rats. Comparison with the accumulation of these acids in developing rat brain].
Quantitative data are presented on the fatty acid composition of rat alpha-fetoprotein (AFP) and serum albumin, (SA), and of brain extracts of suckling rats. In AFP and SA preparations, 40% and 13%, respectively, of total fatty acids present are polyenoic acids. Among them, docosahexaenoic acid is quantitatively the most important in AFP, while in SA, arachidonic acid is largely predominant. Both docosahexaenoic and arachidonic acids were the predominant polyenoic acids in brain extracts. The rate of accumulation of these acids in the brain of suckling rats and the rate of AFP secretion during the same period showed a maximum around 10--12 days after birth. These results suggest that AFP and SA play an important role in the transport and the incorporation of polyunsaturated fatty acids in the developing brain.
Aging↗
Retrodifferentiation and the fetal patterns of gene expression in cancer.
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Animals↗
An electrophoretic assay for plasminogen activator.
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Animals↗
[Abortive effect of autologous anti-alpha-fetoprotein antibodies in the rat].
Female Commentry Rats 80--85 days old, were immunized by 5 intramuscular injections of Mouse alphafetoprotein (AFP) and then mated. After fertilization a supplementary injections was administered. The animals were bled at different times and killed immediately after the last bleeding on the 19 or 20th day of gestation. Titers of AFP and of autologous anti-AFP antibodies in the maternal blood were determined as well as the AFP concentration in the pooled amniotic fluids from live embryos of each litter. Compared to non-immunized control series, the total of live and dead embryos per litter in animals immunized with Mouse AFP showed no difference. However, the number of live embryos was on the average 50% lower than that in the control series. The serum titers of AFP and of antibodies to autologous AFP in immunized pregnant Rats bearing dead embryos decreased concomitantly with the number of live embryos. The results reported herein demonstrate that the presence of anti-autologous AFP antibodies in pregnant Rats correlates with the interruption of development in a significant proportions of embryos. This suggests that certain spontaneous abortions in the Rat and perhaps in other mammals can be explained by the rupture of immunological tolerance to autologous AFP.
Abortion, Spontaneous↗