Biomedical subjects

J Scarborough

Publications and source records attributed to J Scarborough.

At least 19 recordsLinked to original sources

PubMed1999

The vomeronasal organ in the human embryo, studied by means of three-dimensional computer reconstruction.

The human vomeronasal organ is of interest because of its potential role in sex pheromone detection. Due to the scarcity of early human material, studies of its development have concentrated on fetal rather than embryonic stages. The availability of embryonic specimens in the Walmsley Collection has enabled us to study the development of the vomeronasal organ (VNO) in human embryos between Carnegie Stages 17 and 23. Embryos at Carnegie Stage 17 or below showed no evidence of a VNO. One embryo with characteristics intermediate between Carnegie stages 17 and 18 was the earliest to show evidence of a VNO, in the form of a shallow indentation. All embryos at Carnegie Stages 18 or later had VNOs. Three-dimensional computer reconstructions were made of the VNO in each specimen where this was possible. This in part depended on the plane of section. The total volume and lumen volume were measured from these reconstructions and the volume of the vomeronasal epithelium was calculated by subtraction. A generally consistent increase in total volume and epithelial volume was observed with increasing developmental stage. The lumen contributed rather little to the total volume at these stages.

Embryonic and Fetal Development↗

PubMed1997

The study of early human embryos using interactive 3-dimensional computer reconstructions.

Tracings of serial histological sections from 4 human embryos at different Carnegie stages were used to create 3-dimensional (3D) computer models of the developing heart. The models were constructed using commercially available software developed for graphic design and the production of computer generated virtual reality environments. They are available as interactive objects which can be downloaded via the World Wide Web. This simple method of 3D reconstruction offers significant advantages for understanding important events in morphological sciences.

Computer Communication Networks↗

PubMed1994

Engraftment of human hematopoietic precursor cells with secondary transfer potential in SCID-hu mice.

Human fetal bone fragments implanted subcutaneously in immunodeficient (SCID) mice maintain active human hematopoiesis. In this study, we show that this human hematopoietic microenvironment supports the engraftment and differentiation of HLA-mismatched, CD34+ primitive hematopoietic progenitor cells isolated from fetal and adult human bone marrow (BM). The BM CD34+ cells were depleted of CD2, CD14, CD15, CD16, glycophorin A, and CD19 lineage-committed cells (CD34+Lin-). Donor cell engraftment was manifested by the presence of B (CD19+) and myeloid (CD33+) cells of donor HLA phenotype. Successful engraftment was observed as early as 4 weeks after fetal BM donor cell injection and sustained for at least 12 weeks, with engraftment success rates of 100% (11/11 grafts) and 92% (11/12 grafts) at 8 and 12 weeks, respectively. Mixed BM chimerism of donor and endogenous cells was consistently observed in SCID-hu bones successfully engrafted with HLA-mismatched CD34+Lin- donor cells. Preconditioning of the SCID-hu bone with a single dose of sublethal (350 rad) whole body irradiation (WBI) immediately before cell injection enhanced the repopulation of the bone grafts with donor cells and, in some instances, resulted in complete repopulation. After WBI, as few as 500 fetal bone marrow CD34+Lin- cells injected in the human bone grafts resulted in donor-derived hematopoiesis. Donor progenitor cells recovered from the SCID-hu bone grafts 8 weeks postinjection had the capacity to repopulate secondary groups of HLA-disparate fetal human bones in SCID-hu mice with B and myeloid cells as well as CD34+ cells in some recipients. In addition, these cells repopulated fetal human thymus fragments in SCID mice with donor thymocytes including immature CD4+CD8+ and mature CD4+CD8- as well as CD4-CD8+ subsets. These results indicate that the fetal human bone implants of SCID-hu mice can support the maintenance of a cell population that has both multilineage potential and repopulating potential for periods of time as long as 16 weeks. The SCID-hu bone model consistently supported the engraftment of both fetal and adult CD34+Lin- cells without the administration of exogenous human cytokines to these animals. This model is currently being used to permit the isolation and characterization of candidate human hematopoietic stem cells (HSCs) and provide important information critical for human HSC therapy in humans.

Animals↗

PubMed1991