Search results for "MAM"
showing 10 items of 1679 documents
Cadmium induces an apoptotic response in sea urchin embryos.
2007
Cadmium is a heavy metal toxic for living organisms even at low concentrations. It does not have any biological role, and since it is a permanent metal ion, it is accumulated by many organisms. In the present paper we have studied the apoptotic effects of continuous exposure to subacute/sublethal cadmium concentrations on a model system: Paracentrotus lividus embryos. We demonstrated, by atomic absorption spectrometry, that the intracellular amount of metal increased during exposure time. We found, using terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay, that long treatments with cadmium triggered a severe DNA fragmentation. We demonstrated, by immunocytochemistry …
The serosa of Manduca sexta (Insecta, Lepidoptera): ontogeny, secretory activity, structural changes, and functional considerations
2001
In Manduca sexta, the blastoderm forms successively and becomes immediately cellularized as the cleavage energids reach the surface of the oocyte. Presumptive serosal cells are large and contain 2 or 4 large polyploid nuclei; presumptive embryonic cells are small and mononuclear. All parts of the blastoderm participate in the uptake and digestion of yolk material. About 10 h post-oviposition, the blastoderm breaks at the amnioserosal fold and the extraembryonic part closes above the germ band and constitutes the serosa (12 h post-oviposition, i.e. 10% development completed). At once, the serosa starts to secrete a cuticle consisting of an epi- and a lamellated endocuticle. Detachment of the…
Human exome and mouse embryonic expression data implicate ZFHX3, TRPS1, and CHD7 in human esophageal atresia
2020
Introduction Esophageal atresia with or without tracheoesophageal fistula (EA/TEF) occurs approximately 1 in 3.500 live births representing the most common malformation of the upper digestive tract. Only half a century ago, EA/TEF was fatal among affected newborns suggesting that the steady birth prevalence might in parts be due to mutational de novo events in genes involved in foregut development. Methods To identify mutational de novo events in EA/TEF patients, we surveyed the exome of 30 case-parent trios. Identified and confirmed de novo variants were prioritized using in silico prediction tools. To investigate the embryonic role of genes harboring prioritized de novo variants we perfor…
Apical dendritic spines and axonic terminals in the bipyramidal neurons of the dorsomedial cortex of lizards (Lacerta).
1984
Gold-toned bipyramidal neurons of the dorsomedial cortex of Lacerta have been studied using light and electron microscopy. The spines have been classified as stubby, mushroom-shaped or thin. Thin and mushroom-shaped spines are only found on proximal and intermediate dendritic segments, whereas stubby spines are found on distal dendritic segments. A Timm's method modification for electron microscopy (sulphide-osmium procedure) has been used. Timm-positive axonal endings usually synapse on thin and mushroom-shaped spines, whereas Timm-negative axonal endings usually synapse on stubby spines. Timm-positive afferents and their post-synaptic spines on bipyramidal neurons of Lacerta's dorsomedial…
Highly restricted expression at the ectoderm–endoderm boundary of PIHbox 9, a sea urchin homeobox gene related to the human HB9 gene
1998
Abstract Characterisation of a sea urchin (P. lividus) homeobox gene PIHbox 9 is reported. The homeodomain of PIHbox9 is 95% identical to the homeodomain of the human HB9 gene, indicating that the two genes are highly related. Temporal expression analysis during sea urchin embryogenesis showed an absence of transcripts at early cleavage stages. At late gastrula stage, transcripts were barely detectable and reached the highest abundance at prism/early pluteus stages. By whole mount in situ hybridisation we observed a highly restricted expression in a few cells of the ectoderm–endoderm boundary of embryos at the prism stage. At pluteus stages, expression of PIHbox 9 was confined around the an…
A temperature-sensitive brain tumor suppressor mutation of Drosophila melanogaster: Developmental studies and molecular localization of the gene
1993
The recessive-lethal, temperature-sensitive (ts) mutation of the tumor suppressor gene lethal(3)malignant brain tumor (l(3)mbt) causes in a single step the malignant transformation of the adult optic neuroblasts and ganglion mother cells in the larval brain at the restrictive temperature of 29 degrees C. The transformed cells are differentiation-incompetent and grow autonomously in a lethal and invasive fashion in situ in the brain as well as after transplantation in vivo into wild-type adult hosts. The imaginal discs show epithelial overgrowth. At the permissive temperature of 22 degrees C development is completely normal. The ts-period of gene activity responsible for 100% brain tumor sup…
saliva, a new Drosophila gene expressed in the embryonic salivary glands with homologues in plants and vertebrates.
1998
saliva (slv) transcription begins at the salivary gland placodes and continues on throughout development as salivary glands invaginate and reach their final location and morphology. saliva is located cytogenetically in 76A/B, and encodes a 226-amino-acid protein with four hydrophobic domains. A Northern blot detects a 1.6-kb transcript throughout development. Database similarity searches reveal homology to proteins from Caenorhabditis, Lilium, Medicago and mouse.
Rat fetuin: distribution of protein and mRNA in embryonic and neonatal rat tissues
1998
Fetuin is a serum protein widely distributed in the animal kingdom and found in all mammalian species so far investigated. It is mainly a fetal protein, in the sense that the highest concentrations are found in serum and body fluids of embryos and fetuses. In order to elucidate possible biological functions of fetuin, we have studied its synthesis and distribution during the prenatal development of the rat with immunohistochemistry and in situ hybridization. We have isolated fetuin from rat serum and produced an antibody against this protein. In situ hybridization was performed using a 375-nucleotides-long digoxigenin-labeled riboprobe. Fetuin was unevenly distributed in all organ systems d…
MR-Mammographie zur Responsekontrolle bei primärer Chemobrachytherapie des BET-inoperablen Mammakarzinoms
2001
Ziel: Evaluierung (1) moglicher storender Effekte neoadjuvanter Chemobrachytherapie auf die MR-Mammographie, (2) der Eignung der MRM zur Bestimmung der Resttumorgrose nach Therapie und (3) der Eignung der MRM zur Prognose des Gesamtansprechens nach den ersten Therapiezyklen. Methoden: 14 Patientinnen, die an einer praoperativen Tumorreduktionstherapie (4 Zyklen Chemotherapie kombiniert mit interstitieller Radiotherapie) teilnahmen, wurden mittels dynamischer MR-Mammographie (1 T, zeitliche Auflosung 93 s, raumliche Auflosung 1,9 mm, 0,1 mmol/kg GdDTPA) vor Therapie, nach den ersten beiden Chemotherapiezyklen, nach der Radiotherapie und dem dritten Zyklus sowie nach Therapieabschluss untersu…
Lymphatic endothelial progenitors bud from the cardinal vein and intersomitic vessels in mammalian embryos.
2012
Abstract The lymphatic vasculature preserves tissue fluid balance by absorbing fluid and macromolecules and transporting them to the blood vessels for circulation. The stepwise process leading to the formation of the mammalian lymphatic vasculature starts by the expression of the gene Prox1 in a subpopulation of blood endothelial cells (BECs) on the cardinal vein (CV) at approximately E9.5. These Prox1-expressing lymphatic endothelial cells (LECs) will exit the CV to form lymph sacs, primitive structures from which the entire lymphatic network is derived. Until now, no conclusive information was available regarding the cellular processes by which these LEC progenitors exit the CV without co…