Search results for "Embryon"
showing 10 items of 988 documents
Identification of Insulin in Chick Embryo Retina During Development and Its Inhibitory Effect on DNA Synthesis
1992
Incubation of chick embryo retinal explants with insulin resulted in a pronounced inhibition of thymidine uptake and incorporation into trichloroacetic acid-insoluble fraction. The inhibitory effect was highest with explants from embryos at day 7 and day 8, and thereafter it declined markedly with the age of embryos until day 11. A time-course study of the effect revealed that the inhibition occurred after a lag time; both thymidine uptake and incorporation were not altered significantly after 2-6 h of incubation with insulin, but began to decrease thereafter, reaching the maximum after 16 h. The effect was also dose dependent. After 16 h of incubation, the maximal inhibition (65%) was foun…
Developmental expression of human cartilage matrix protein.
1994
Cartilage matrix protein (CMP) is a non-collagenous component of cartilage with a yet unknown function. In this study we used in situ hybridization to investigate the temporal and sptial distribution of CMP transcripts during human embryonic and early fetal development, and compared it to the pattern of expression observed for collagen types I, II, X, and decorin. The distribution of CMP and collagen type II transcripts followed a similar pattern in the embryonic bone anlage, the fetal growth plate, and the developing vertebral column. Expression was highest in the upper hypertrophic and lower proliferative zone, whereas calcified cartilage was negative throughout the different stages of bo…
Signaling through BMPR-IA regulates quiescence and long-term activity of neural stem cells in the adult hippocampus.
2010
SummaryNeural stem cells (NSCs) in the adult hippocampus divide infrequently, and the molecules that modulate their quiescence are largely unknown. Here, we show that bone morphogenetic protein (BMP) signaling is active in hippocampal NSCs, downstream of BMPR-IA. BMPs reversibly diminish proliferation of cultured NSCs while maintaining their undifferentiated state. In vivo, acute blockade of BMP signaling in the hippocampus by intracerebral infusion of Noggin first recruits quiescent NSCs into the cycle and increases neurogenesis; subsequently, it leads to decreased stem cell division and depletion of precursors and newborn neurons. Consistently, selective ablation of Bmpr1a in hippocampal …
MUCI, glycans and the cell-surface barrier to embryo implantation
2001
As it approaches the maternal surface, the attaching embryo encounters the epithelial glycocalyx, which contains the mucin, MUC1. A high density of MUC1 at the cell surface can inhibit cell adhesion. This raises the possibility of the existence of a uterine barrier to implantation that might allow maternal rejection of poorer quality embryos. To investigate the mechanism of implantation, human embryos were incubated with endometrial epithelial monolayers. Hatched blastocysts were found to attach readily to the epithelial surface. MUC1 was lost from epithelial cells beneath and near to the attached embryo, while normal expression persisted in neighbouring cells.
Abnormal development of pacinian corpuscles in double trkB;trkC knockout mice.
2006
Pacinian corpuscles depend on either Aalpha or Abeta nerve fibers of the large- and intermediate-sized sensory neurons for the development and maintenance of the structural integrity. These neurons express TrkB and TrkC, two members of the family of signal transducing neurotrophin receptors, and mice lacking TrkB and TrkC lost specific neurons and the sensory corpuscles connected to them. The impact of single or double targeted mutations in trkB and trkC genes in the development of Pacinian corpuscles was investigated in 25-day-old mice using immunohistochemistry and ultrastructural techniques. Single mutations on trkB or trkC genes were without effect on the structure and S100 protein expr…
Ovicidal Activity of Maternally Applied Ecdysteroids in the Large Milkweed Bug (Heteroptera: Lygaeidae)
1982
Exogenous ecdysteroids (ecdysone, 20-hydroxyecdysone and makisterone A) administered to reproducing females of Oncopelus fasciatus (Dallas) reduced egg hatch drastically. The ovicidal activity apparently stemmed from ecdysteroids—unchanged hormone or metabolites—transferred from mother into oocyte. Different stages of embryogenesis were affected. Makisterone A, the predominant ecdysteroid in normal embryos, is by far the most effective ecdysteroid.
Stellenwert des Tumormarkers CA 19–9 in der Differentialdiagnose von Raumforderungen im Pankreaskopf
1996
In 96 patients (ductal pancreatic carcinoma, n = 34; periampullary carcinoma, n = 43; chronic pancreatitis, n = 19) the role of CA 19-9 in the diagnosis of lesions of the head of the pancreas were evaluated. The sensitivity for ductal pancreatic carcinoma was 73.3%, for periampullary carcinoma 48.8%, and specificity was 63.2%. Carcinoembryonic antigen was elevated only in every fifth patient. Even when combining the two tumor markers no increase in sensitivity could be observed. The low specificity of 63%, which decreased to 33% in the case of obstructive jaundice, does not allow adequate preoperative differentiation between cancer patients and those with chronic pancreatitis. In cases of p…
0201: Cardiac surgery associated with cardiopulmonary bypass in patients with stable coronary disease: growth differentiation factor-15 (GDF- 15) as …
2014
BackgroundGrowth differentiation factor-15 (GDF-15) has been identified as a strong marker for cardiovascular disease; however, no data are available concerning the role of GDF-15 in the occurrence of organ dysfunction during cardiac surgery associated with cardiopulmonary bypass (CPB).MethodsThirty four patients, programmed to have non-urgent coronary artery bypass grafting (CABG), were included in our study. Arterial blood samples were taken sequentially from anesthesia induction (IND) until 24h after arrival at the cardiovascular intensive care unit (ICU). Plasma levels of GDF-15, follistatin-like 1 (FLST1), myeloperoxidases (MPO), hydroperoxides and plasma antioxidant status (PAS) were …
Programming of neural progenitors of the adult subependymal zone towards a glutamatergic identity by Neurogenin2
2017
ABSTRACTWhile the adult subependymal zone (SEZ) harbors pools of distinct neural stem cells that generate different types of GABAergic interneurons, a small progenitor population in the dorsal SEZ expresses Neurog2 and gives rise to glutamatergic neurons. Here we investigated whether SEZ progenitors can be programmed towards glutamatergic neurogenesis through forced expression of Neurog2. Retrovirus-mediated expression of Neurog2 induced the glutamatergic neuron lineage markers Tbr2 and Tbr1 in cultured SEZ progenitors which subsequently differentiated into functional glutamatergic neurons. Likewise, retrovirus-mediated expression of Neurog2 in dividing SEZ progenitors within the adult SEZ …
Antiphosphatidylserine Antibodies Affect Rat Yolk Sacs in Culture: a Mechanism for Fetal Loss in Antiphospholipid Syndrome
2004
PROBLEM: A variety of reproductive impairments have been reported in the context of the antiphospholipid syndrome (APS). APS is associated with the presence of antibodies to negatively charged phospholipids that may affect the outcome of pregnancy. METHOD OF STUDY: Rat embryos were cultured within their yolk sacs. The effects of two antiphosphatidylserine monoclonal aPS antibodies (HL5B, RR7F) regarding their influence on growth and apoptotic events of the yolk sacs, as well as on growth and the morphology of the embryos, were studied. RESULTS: Exposure of rat embryos and their yolk sacs to aPS inhibited yolk sac growth. Moreover, increased number of apoptotic events of giant cells in the a…