scholarly journals Histomorohological Studies on Ovary of Guppy (Poecilia Reticulata) And Development of Follicular Placenta

2021 ◽  
pp. 275-278
Author(s):  
Jagtap Nanda ◽  
Mote L. T.
Keyword(s):  
Connective Tissue ◽  
Poecilia Reticulata ◽  
Placental Tissue ◽  
Yolk Sac ◽  
Vascular Network ◽  
Mosquito Vectors ◽  
Water Reservoirs ◽  
Larvivorous Fish

The larvivorous fish Poecilia reticulata was propagated prolifically in the garden for control of mosquito vectors and later redistributed in a number of water reservoirs, in different villages nearby Dapoli. The gravid live bearing females were quickly dissected for their ovaries and embryos. The developed embryo with yellow rounded yolk sac, the remnants of the follicular placental tissue and thick vascular network of connective tissue was also observed.

scholarly journals Initiation of hematopoiesis and vasculogenesis in murine yolk sac explants

Blood ◽  
1995 ◽  
Vol 86 (1) ◽  
pp. 156-163 ◽  
Author(s):  
J Palis ◽  
KE McGrath ◽  
PD Kingsley
Keyword(s):  
Endothelial Cells ◽  
Network Formation ◽  
Globin Gene ◽  
Primitive Streak ◽  
Yolk Sac ◽  
Vascular Network ◽  
Globin Mrna ◽  
Capillary Networks ◽  
Stage Of Development ◽  
Extraembryonic Mesoderm

The blood islands of the visceral yolk sac (VYS) are the initial sites of hematopoiesis in mammals. We have developed a yolk sac explant culture system to study the process of blood cell and endothelial cell development from extraembryonic mesoderm cells. No benzidine-positive cells or beta H1-globin mRNA expression was detected at the primitive streak or neural plate stage of development (E7.5). However, when isolated E7.5 dissected tissues were cultured for 36 to 72 hours in serum-free medium, hundreds of hemoglobin-producing cells and embryonic globin gene expression were identified in both intact yolk sac and VYS mesoderm explants. Explanted E7.5 extraembryonic mesoderm tissues thus recapitulate in vivo primitive erythropoiesis and do not require the presence of a vascular network or the VYS endoderm. Yolk sac blood islands also contain endothelial cells that arise by vasculogenesis and express flk-1. We detected flk-1 mRNA as early as the primitive streak stage of mouse embryogenesis. Culture of embryo proper and intact VYS explants, which contain both mesoderm and endoderm cells, produced capillary networks and expressed flk-1. In contrast, vascular networks were not seen when VYS mesoderm was cultured alone, although flk-1 expression was similar to that of intact VYS explants. The addition of vascular endothelial growth factor to VYS mesoderm explants did not induce vascular network formation. These results suggest that the VYS endoderm or its extracellular matrix is necessary for the coalescence of developing endothelial cells into capillary networks.

Vascularization in the murine allantois occurs by vasculogenesis without accompanying erythropoiesis

Development ◽  
1998 ◽  
Vol 125 (22) ◽  
pp. 4507-4520 ◽  
Author(s):  
K.M. Downs ◽  
S. Gifford ◽  
M. Blahnik ◽  
R.L. Gardner
Keyword(s):  
Endothelial Cells ◽  
Blood Vessels ◽  
Cell Lineage ◽  
Immunohistochemical Analysis ◽  
Distal Region ◽  
Yolk Sac ◽  
Neural Plate ◽  
Vascular Network ◽  
Erythroid Cells ◽  
Erythroid Precursor

The aim of this study was to determine whether the blood vessels of the murine allantois are formed by vasculogenesis or angiogenesis. Morphological analysis revealed that differentiation of allantoic mesoderm into an outer layer of mesothelium and an inner vascular network begins in the distal region of the allantois, which is most remote from other tissues, as early as the late neural plate stage (approximately 7.75 days postcoitum). Nascent blood vessels were not found in the base of the allantois until 4-somite pairs had formed in the fetus (approximately 8.25 days postcoitum), and vascular continuity with the yolk sac and fetus was not present until the 6-somite-pair stage (approximately 8.5 days postcoitum). Immunohistochemical analysis demonstrated that flk-1, a molecular marker of early endothelial cells, is expressed in significantly more distal than basal core cells in the early allantois and never in mesothelium. Furthermore, synchronous grafting of donor yolk sac containing blood islands into blood islands of headfold-stage host conceptuses provided no evidence that the yolk sac contributes endothelial cells to the allantois. Finally, when removed from conceptuses and cultured in isolation, neural plate and headfold-stage allantoises formed a conspicuous vascular network that was positive for Flk-1. Hence, the vasculature of the allantois is formed intrinsically by vasculogenesis rather than extrinsically via angiogenesis from the adjacent yolk sac or fetus. Whether allantoic vasculogenesis is associated with erythropoiesis was also investigated. Benzidine-staining in situ revealed that primitive erythroid cells were not identified in the allantois until 6-somite pairs when continuity between its vasculature and that of the yolk sac was first evident. Nevertheless, a small number of allantoises removed from conceptuses at a considerably earlier stage were found to contain erythroid precursor cells following culture in isolation. To determine whether such erythroid cells could be of allantoic origin, host allantoises were made chimeric with lacZ-expressing donor allantoises that were additionally labeled with [3H]methyl thymidine. Following culture and autoradiography, many lacZ-expressing benzidine-stained cells were observed in donor allantoises, but none contained silver grains above background. Moreover, no cells of donor allantoic origin were found in the fetus or yolk sac. Hence, vasculogenesis seems to be independent of erythropoiesis in the allantois and to involve a distal-to-proximal gradient in differentiation of allantoic mesoderm into the endothelial cell lineage. Furthermore, this gradient is established earlier than reported previously, being present at the neural plate stage.

scholarly journals THE HISTOGENESIS OF BASEMENT MEMBRANES

1963 ◽  
Vol 117 (3) ◽  
pp. 339-348 ◽  
Author(s):  
G. B. Pierce ◽  
A. R. Midgley ◽  
J. Sri Ram
Keyword(s):  
Epithelial Cells ◽  
Connective Tissue ◽  
Basement Membrane ◽  
Yolk Sac ◽  
Basement Membranes ◽  
Ground Substance ◽  
Epithelial Secretion ◽  
Reichert's Membrane ◽  
Yolk Sac Cells

A parietal yolk sac carcinoma of the mouse that secretes large quantities of basement membrane-like material has been used to study the formation of basement membranes. Suitably characterized fluorescein-labeled antibodies against this material stained basement membranes of epithelial structures and vessels, as well as reticulin. When absorbed with reticulin and vascular basement membranes of the spleen until these structures no longer fluoresced, the antibody still stained the basement membrane-like material of the tumor, its normal embryonic counterpart (Reichert's membrane), and the basement membranes at the bases of epithelial cells. The observation made previously that parietal yolk sac cells secreted, in the absence of connective tissue and reticulin, the basement membrane (Reichert's membrane) upon which they rested has been confirmed through the localization of ferritin-labeled antibody to the endoplasmic reticulin of the secreting cells. Since a basement membrane proven to be an epithelial secretion is antigenically similar to basement membranes at the bases of all epithelial cells studied but antigenically different from connective tissue elements, it is postulated that the basement membranes at the bases of epithelial cells in general are an epithelial secretion, and are not a condensation of ground substance as is commonly believed.

Experimental Transferable Vascular Bed for Laryngotracheal Reconstruction: Further Observations

1993 ◽  
Vol 102 (2) ◽  
pp. 144-151 ◽  
Author(s):  
Pierre R. Delaere ◽  
Jos Mebis ◽  
Willy D. Boeckx ◽  
Frans Ostyn ◽  
Boudewijn Van Damme ◽  
...  
Keyword(s):  
Connective Tissue ◽  
Free Flap ◽  
Vascular Network ◽  
External Ear ◽  
Free Graft ◽  
Vascular Bed ◽  
Major Disadvantage ◽  
Laryngotracheal Reconstruction ◽  
Natural Tendency ◽  
Internal Lining

Free fascia flaps have proven most reliable in providing a vascular bed for an epithelial free graft without adding bulk. They may be a useful tool for laryngotracheal reconstruction. A free flap consisting of a vascular network running in connective tissue can be developed on the rabbit external ear. The vascular characteristics of this flap were examined to test the reliability of the transferable vascular bed in laryngotracheal repair. The perichondrial free flap is useful for bringing an internal lining inside the lumen and for circumferential protection of supporting tissue. However, the natural tendency for surface contraction of perichondrium is a major disadvantage.

scholarly journals DIFFERENCES OF CULEX SPP AND AEDES SPP LARVAE MORTALITY RATES ON THE USE OF THEMEFOS

2021 ◽  
Vol 12 (1) ◽  
pp. 99-105
Author(s):  
Wahyu Darmawan
Keyword(s):  
Mortality Rate ◽  
Filter Paper ◽  
Human Activities ◽  
Mortality Rates ◽  
Probit Analysis ◽  
Mosquito Vectors ◽  
Water Reservoirs ◽  
Stagnant Water ◽  
Quasi Experimental ◽  
Small Discharge

Eradication of the mosquito vectors that cause several diseases is still being carried out today where methods are still being developed. This research aims to identify the mortality rate of Culex spp. and Aedes spp. larvae for the use themefos or abate with sowed and wrapped of filter paper. The author uses quasi-experimental to observe that mortality. The design was devided into two groups, giving themepos/abate with a national dose of (1gr/10 liters of water) in 24 hours with threatment sowed and wrapped of filter paper through the analysis of varians/annova test to observe the varians of the time of mortality of Culex spp. and Aedes spp. larvae as well as probit analysis to see the probability of time of the larvae’s death.The result of this research is no defference in the mortality of Culex spp. and Aedes spp. larvae for the uses of themefos/abate with sowed and wrapped of filter paper. The authors suggestion is giving themefos or abate by wrapping filter paper preverably for larvae in a stagnant water such as Aedes spp larvae because it does not provide residual granules in water reservoirs used for human activities while the used of themepos/abate with sowed can also be used for a stagnant water or has a small discharge.

scholarly journals Bioactivity and composition of a preserved connective tissue matrix derived from human placental tissue

2018 ◽  
Vol 106 (8) ◽  
pp. 2731-2740 ◽  
Author(s):  
Joseph Irvin ◽  
Carina Danchik ◽  
Joseph Rall ◽  
Annie Babcock ◽  
Matthew Pine ◽  
...  
Keyword(s):  
Connective Tissue ◽  
Placental Tissue ◽  
Human Placental Tissue ◽  
Connective Tissue Matrix ◽  
Tissue Matrix

Visualizing the spatiotemporal pattern of yolk sac membrane vascular network by enhanced local fractal analysis

2021 ◽  
Author(s):  
Peilun Li ◽  
Qing Pan ◽  
Sheng Jiang ◽  
Wolfgang M. Kuebler ◽  
Axel R. Pries ◽  
...  
Keyword(s):  
Fractal Analysis ◽  
Yolk Sac ◽  
Vascular Network ◽  
Spatiotemporal Pattern
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