An organism with a capsule will show a halo around the cell. Negative-staining with nigrosin or India ink is a quick and easy method to gain information about the presence or absence of capsules or any other layers around bacteria. Detection of prominent GATA-3 expression, restricted to the endoderm of the pre-allantoic region and allantoic bud and followed by expression of GATA-2, is novel in the context of organ formation and endoderm specification with respect to the emergence of HC.
Taken together, these results extend earlier findings on the commitment of mesoderm to endothelial and hematopoietic lineages in allantois.
Moreover, using hetero-specific grafts between chick and quail embryos, we were able to demonstrate that the allantoic vascular network develops from intrinsic progenitors. Using in vitro culture techniques, we have shown that those allantoic buds, dissected out before the circulation between the bud and the rest of the embryo is established, produce elliptic erythrocytes typical of the definitive lineage. GATA-3 is detected at least until EID 8 GATA-2, until EID 3-the latest times examined for these factors. Shortly before the allantoic bud grows out, GATA-2 is expressed in the endoderm and, at the same time, the hemangioblastic program is initiated in the mesoderm. This hematopoietic process takes place before the vascular network connecting the allantois to the embryo is established.Īs far as the endoderm is concerned, GATA-3 messenger (m)RNA is found in the region where the allantois differentiates before the posterior intestinal portal becomes anatomically distinct. Blood island-like structures that contain both CD45 + cells and cells that accumulate hemoglobin differentiate and look exactly like the blood islands in the yolk sac. Shortly afterward, it is followed by the expression of several transcription factors (GATA-1, GATA-2 and SCL/tal-1). VEGF-R2 is expressed in the mesoderm, at least from stage HH17 onward. The allantois follows a program of development characterized by the prominent expression of several “hemangioblastic” genes in the mesoderm and other genes in the associated endoderm.
It displays conspicuous red cells even before vascularization, indicating that hematopoiesis occurs at this site quite independently of the rest of the embryo. Using India ink or AcLDL-Di micro-angiographies, we have established that the allantois becomes vascularized at 75–80 hours of incubation. Dominique Dunon, in Avian Immunology (Second Edition), 2014 3.4.4 Cellular and Molecular Identification of Allantois-Associated Hematopoiesis Despite the advantages for clinical applications, India ink has some limitations, including a tendency to diffuse and moderate EPR sensitivity.
The suitability of the clinical EPR system for pO 2 measurements in superficial tumors (< 10 mm depth) using India ink has been demonstrated for locations ranging from the feet, to the anterior and posterior surfaces of the torso, and scalp ( Khan, Williams, Hou, Li, & Swartz, 2007 Khan et al., 2006 Swartz, Hou, et al., 2014 Swartz, Williams, et al., 2014 Williams et al., 2010). In preclinical studies, we have extensively used oxygen-sensitive India ink as a probe to measure the effects of split-dose radiation on the oxygenation of RIF-1 and MTG-B tumors in mice ( Jiang et al., 1996 Nakashima et al., 1995 O'Hara et al., 1998). Given the fact that some of the India inks have already been used as a tissue marker in patients for several decades, they can also be used for oximetry in patients provided they have oxygen-sensitive carbon particles. The preparation and biocompatibility testing of oxygen-sensitive inks for EPR oximetry have been described previously ( Charlier, Beghein, & Gallez, 2004 Gallez et al., 1998 Gallez & Mader, 2000 Jordan et al., 1998). Fortuitously, carbon black particles in some of the India ink formulations contain stable radical species at sufficient concentrations with EPR signals that are sensitive to the presence of oxygen ( Goda et al., 1995 Jiang et al., 1996 Jordan, Baudelet, & Gallez, 1998 Khan et al., 2005 Nakashima, Goda, Jiang, Shima, & Swartz, 1995 O'Hara, Goda, Demidenko, & Swartz, 1998 Swartz, Hou, et al., 2014 Swartz, Liu, Goda, & Walczak, 1994 Swartz, Williams, et al., 2014 Williams et al., 2010) ( Fig. India ink also has a long history of clinical use as an anatomic marker for surgery and radiotherapy. India ink is a suspension of carbon black particles in a medium (such as ethylene glycol) and is commonly used in pens for writing, drawing, or epidermal tattooing.
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