ISSN:
0002-9106
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
Notes:
This combined light, transmission and scanning electron microscopic study describes and correlates the morphologic features of various types of cells present in normal human amniotic fluid (AF), during various stages of gestation. The aim of this investigation was to identify and characterize the viable cell population of AF cells as they pertain to the origin of AF cells growing in culture and their use for prenatal diagnosis.In all AF samples, including those obtained during the time period critical for prenatal diagnostic tests (14-16 weeks gestation), the majority of AF cells had the morphologic features of large squamous epithelial cells. By transmission and scanning electron microscopy these cells were characterized as keratinizing or non-keratinizing squamous epithelial cells and resembled the cells found on various fetal surfaces (i.e., buccal mucosa, skin, etc.). As judged by Trypan blue stainability and the presence of nuclear and cytoplasmic degenerative changes, the AF squamous cells were considered non-viable, and thus unlikely to grow in culture.The AF cells considered to be viable, because of their excellent ultrastructural preservation and exclusion of Trypan blue stain, formed only 10-15% of AF cells. Amongst this viable population, at least two morphologically distinct cell types were identified. One type had morphologic and functional characteristics of macrophages. The AF macrophages differed from other AF cells by the presence of a strong acid phosphatase reaction, numerous phagosomes and an ability to phagocytose in vitro, both latex particles and bacteria. Although AF macrophages appear to be a normal cell constituent of human AF, their origin and significance is unknown. The second type of viable AF cells appeared as single cells or in clusters and resembled the epithelial cells of amniotic lining. The amniotic cells showed excellent ultrastructural preservation of nuclei and cytoplasmic components. In contrast to AF macrophages, the amniotic cells contained cytoplasmic glycogen, possessed fine, regular surface microvilli and lacked both phagosomes and phagocytic capacity in vitro. It is proposed that these two types of viable AF cells may be the sources of cells growing in culture and could be responsible for the morphologic and biochemical heterogeneity of cultured AF cells.
Additional Material:
1 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/aja.1001510108
