The clinical and (dermato) pathological signifcance of neural crest cells. Blaschko lines and dermatoses. Neurocristopathies

In the course of their migration the neural crest cells reach all parts of the developing embryo. The frst wave of the derivatives of these cells the melanoblasts and melanocytes harbour in the epidermis and hair follicles during the dorsolateral migration. A number of signal molecules and proteases play an important role in the course of melanocyte migration through the extracellular matrix. The Mongolian spots appear as a consequence of the transient inhibition of melanocyte migration and in the case of fnal obstruction the Ota-, or. Ito nevuses. The Blaschko lines based on cutaneous mosaicism are of great diagnostic importance and on the ground of these lines the blaschkitises can appear under the exogenous factors. The blaschkolinear acquired infammatory skin eruption (BLAISE) is an acquired infammatory process. One of its variants is the lichen striatus and the other is the blaschkitis. The blaschkolinear dermatoses can appear usually as a nevoid disease. The pathological development of the neural crest cells can induce pathological processes in other tissues of the body as well, which may appear in the form of the so-called neurocristopathies including approximately ffty manifestations. The knowledge of the diferent pigmentation forms as well as the pathological symptoms of neurocristopathies is of great importance for the clinican from a diagnostic point of view.

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The Effects Hypergravity on the Morphology of Xenopus Embryos

American Journal of Undergraduate Research ◽

10.33697/ajur.2008.016 ◽

2008 ◽

Vol 7 (2) ◽

Author(s):

Rochelle Remus ◽

Darrell Wiens

Keyword(s):

Body Size ◽

Neural Crest ◽

Gravitational Force ◽

Neural Crest Cells ◽

The Body ◽

Control Group ◽

Altered Gravity ◽

Xenopus Embryos ◽

Dorsal Neural Tube ◽

Head Skeleton

Early amphibian development is sensitive to both reduced and elevated gravitational force. But later, following gastrulation and neurulation, a critical population of cells must migrate from the dorsal neural tube outward to destinations throughout the body where they differentiate into a wide variety of critical tissues including head cartilage. These cells, the neural crest cells, respond to extracellular cues and signals that guide migration and differentiation in an intricate process that may also be sensitive to altered gravity. We examined the effects of hypergravity on the migration of neural crest cells to form head skeleton cartilage, and on body size in Xenopus embryos. To investigate this we centrifuged embryos at 7G or 10G, from yolk plug stage (gastrulation) through five days of development to stage 45 when feeding begins. A control group was placed on the centrifuge. After centrifugation, the embryos were fixed, cleared and stained with Alcian Blue to reveal cartilage. We then captured images for analysis to obtain body and head cartilage measurements. We found that hypergravity retarded the growth of Xenopus embryos, possibly via increased load on the cardiovascular system. Surprisingly, it also resulted in significantly larger and more asymmetrical head cartilages, when corrected for body size, but it did not result in a significantly higher frequency of malformations. Our results support the likelihood that hypergravity inhibits body growth and perturbs the formation of neural crest derived head cartilage.

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