Biomedical subjects

J Murillo-González

Publications and source records attributed to J Murillo-González.

4 recordsLinked to original sources

PubMed2004

Magnetic resonance microscopy versus light microscopy in human embryology teaching.

A study was carried out on the application of magnetic resonance microscopy (MRM) in teaching prenatal human development. Human embryos measuring 8 mm, 15 mm, 18.5 mm, and 22 mm were fixed in a 4% paraformaldehyde solution and sections obtained with magnetic resonance imaging (MRI) were compared to those prepared for light microscopy (LM), using the same embryos. The MRM and LM slices were of a similar quality. In the MRM sections, embryonic organs and systems were clearly visible, particularly the peripheral and central nervous systems, and the cardiovascular and digestive systems. The digitalization and clarity of the MRM images make them an ideal teaching aid that is suitable for students during the first years of a health-science degree, particularly medicine. As well as providing students with their first experience of MRM, these images allow students to access, at any time, all embryos used, to assess changes in the positions of different organs throughout their stages of development, and to acquire spatial vision, an absolute requirement in the study of human anatomy. We recommend that this technique be incorporated into the wealth of standard embryonic teaching methods already in use.

Embryo, Mammalian↗

PubMed2001

Evolution of embryology: a synthesis of classical, experimental, and molecular perspectives.

Embryology as a modern science began at the beginning of the 19th century and continued as the classic period until the 1940s. During this period, a body of basic knowledge was established which, generally, described the events of development. From 1940 to 1970 experimental or causal embryology predominated; explanations of secondary causes were demonstrated for development. The decade of the 1970s was a decade of transition that led to the current revolution in molecular biology that began in the 1980s. Molecular biology and its new branch, molecular genetics, shook up the heretofore serene, but already limited, field of embryology. Today the discipline of embryology is being built on the analysis of the results of genetic expression. Embryology is now concerned with understanding development from the viewpoint of the activation and transcription of DNA sequences, which will allow us to approach the first causes or underlying genetic and epigenetic mechanisms of development. As a result, embryology and genetics have fused into a wider biological subdiscipline, developmental biology. Will this be enough to define the full scope of our knowledge of embryonic development? What is certainly evident is that the molecular period of embryology will help achieve a better understanding of the schemata constructed by classic and experimental embryologists. Furthermore, to the degree that the molecular analysis of whatever phenomenon of development requires additional foundational knowledge, classic and experimental embryology will not have exhausted all their possibilities.

Embryology↗

PubMed2001

The human embryo development through MMR.

This study evaluates the use of the Microscopic Magnetic Resonance (MMR) in the human prenatal development. Human embryos (8mm, 15mm, 18mm and 22mm in length) fixed in 4% paraformaldehyde were used. Results were compared with light microscopy (LM) images. The internal configuration of the embryos can be clearly observed as well as many organs such as liver, lungs, heart, including their spatial relationships. In general MMR sections are less clear and show minor details than those by LM. Neverthless, many advantages are provided by using this technique. For example it is possible: a) to make three-dimensional (3-D) surface and internal full or partial reconstructions; b) to evaluate the presence of developmental anomalies; c) to evaluate the tissular preservation degree of the specimens; and d) to apply morphometric techniques to unfixed specimens. In our opinion the advantages derived by using MMR are many and overcome the disadvantages. This study demonstrates that MMR can be incorporated into ordinary laboratory techniques in human development studies, being also an initial election technique opposite to others more aggressive.

Embryonic and Fetal Development↗

PubMed1999

Immunocytochemical study on the triple origin of the sphincter iris in the chick embryo.

The ontogenic development of the sphincter iris has been studied by immunocytochemistry and standard staining on chick embryos from stage 25 HH to the time of hatching. We have used the monoclonal antibody 13F4, a highly specific marker of muscular cells. We have observed three different regions in the iris. In the pupillary region, immunoreactive cells are in continuous contact with the inner epithelium of the pupillary margin. In the intermediate region, the outer epithelium forms buds of pigmented cells that emigrate toward the stroma. In this epithelium cells that are totally or partially unpigmented exist, and they are 13F4 positive. In the sphincter we have observed 13F4 positive cells with melanin granules. In the ciliary region, the immunoreactivity appears in dispersed mesenchymal cells. The present findings are consistent with a triple origin of the sphincter iris in the chick embryo. This muscle is derived from the inner epithelium of the pupillary margin, the intermediate region of the outer epithelium, and from the mesenchymal cells. The cells of the inner epithelium of the pupillary margin are differentiated into smooth muscle cells, and the remaining cells form striated muscle cells.

Animals↗