Yolk retention and yolk sac infection is considered as an important cause of death in chicken as well as in guinea fowl, duck, turkey, quail and goose. The factors which slow down the rate of yolk absorption and may in turn, lead to yolk retention are discussed. Yolk sac infection of bacterial origin is most important among these factors. Other factors which may contribute include posthatch sta...

In this study, 100 day-old broiler chicks were divided into two groups, A and B containing 50 birds each. Experimental infection with E. coli was given intra yolk to group A on day-1 of experiment, while group B was kept as control. Parameters studied were examination of yolk sac, yolk sac:body weight ratio, antibody titer against Newcastle disease virus (NDV) and analysis of fractional serum p...

The murine yolk sac, being the first site of embryonic blood cell production, has long been theorized to contain the migrating hematopoietic stem cells (HSC) that seed the liver and initiate hematopoiesis on day 10.0 postcoitus (pc). However, it remains controversial whether yolk sac cells isolated before day 11.0 pc possess any long-term repopulating HSC activity upon transplantation into adul...

The present studies were performed to further characterize a mouse yolk sac protein which is similar or identical to the vitamin D-dependent intestinal calcium-binding protein (CaBP). Yolk sac protein and purified rat intestinal CaBP displayed full identity upon immunodiffusion (Ouchterlony) using antiserum to the rat intestinal CaBP. Immunoreactive CaBP in yolk sac homogenates eluted from gel ...

OBJECTIVE To review the process of blood-cell formation in the murine and human yolk sac. DATA SOURCES Most articles were selected from the PubMed database. DATA SYNTHESIS The yolk sac is the first site of blood-cell production during murine and human ontogeny. Primitive erythroid cells originate in the yolk sac and complete their maturation, including enucleation, in the bloodstream. Thoug...

Address for Correspondence: Dr. Geetanjali Srivastava, Junior resident IIIrd year,Department of Anatomy, Era’s Lucknow medical college, Lucknow-226003, Uttar Pradesh, India. 9792171135, E-Mail: [email protected] Introduction: The yolk sac is the first extra embryonic structure that becomes sonographically visible within the gestational sac and acts as the primary route of excha...

The mechanisms involved in the induction of yolk sac mesoderm into blood islands and the role of visceral endoderm and mesoderm cells in regulating the restricted differentiation and proliferation of hematopoietic cells in the yolk sac remain largely unexplored. To better define the role of murine yolk sac microenvironment cells in supporting hematopoiesis, we established cell lines from day-9....

(-)-epicatechin gallate (ECg) substantially modifies the properties of Staphylococcus aureus and reversibly abrogates β-lactam resistance in methicillin/oxacillin resistant (MRSA) isolates. We have determined the capacity of ECg to alter the course of infection in zebrafish embryos challenged with epidemic clinical isolate EMRSA-16. At 30 h post fertilization (hpf), embryos were infected by inj...

In order to evaluate the hypothetical activity of foetal hepatic factors on putative yolk-sac haemopoietic stem cells we used the Double Diffusion Chamber (DDC) techniqUe. The DDC were made of a regulator compartment, where foetal hepatic tissue was introduced and a test compartment where visceral yolk-sac cells were cultured. In this system a hepatic signal induced the yolk-sac stem cells to d...