Embryonic tissue

Historically, the development of animal cell culture systems has been dependent upon the development of new types of tissue culture media. Mouse L cells and HeLa cells were developed using a balanced salt solution supplemented with blood plasma, an embryonic tissue extract, and/or serum. In 1955 Eagle developed a nutritionally defined medium, containing all of the essential amino acids, vitamins, cofactors, carbohydrates, salts, and small amounts of dialyzed serum (Table 1). He demonstrated that this minimal essential medium (MEM) supported the long-term growth of mouse L and HeLa ceils. Eagle s MEM was so well defined that the omission of a single essential nutrient eventually resulted in the death of these animal cells in culture. 

Secondary cell cultures, which can be prepared by taking cells from some types of primary culture, usually those derived from embryonic tissue, dispersing them by treatment with trypsin and inoculating some into a fresh batch of medium. A limited number of subcultures can be performed with these sorts of cells, up to a maximum of about 50 before the cells degenerate. 

Yang HY, Lee QP, Rettie AE, Juchau MR. 1994. Functional cytochrome P4503A isoforms in human embryonic tissues expression during organogenesis. Mol Pharmacol 46 ... 

A subsequent study in 2002 of 27 families with a condition known as multiminicore disease (MmD) also linked mutations in SEPNl to disease pathology. Multiple mutations were identified in exons 1, 5, 7, 8, 10, and 11, and the authors also mentioned that this region (RSMD) had been previously linked to MmD. Minicores are lesions by histochemistry of mitochondrial depletion within muscle tissue. The first biochemical study of selenoprotein N aimed to identify the protein localization by immunohistochemistry and found that the primary protein product of several identified mRNAs (splice variants) was a 70 kDa protein present in the endoplasmic reticulum. Two potential ER targeting domains were shown to be present and the peptide expressed from the first exon was shown to be required for localization into the ER. This study also revealed that selenoprotein N was an integral membrane protein that is N-glycosylated. Expression analysis showed pronounced levels in embryonic tissue with a reduction after development and differentiation. 

All of the tissues affected in Klein-Waardenburg syndrome are derived from embryonic tissue in which PAX-3 is expressed. Symptoms include ... 

In such seeds, but not in whole seeds, growth of embryonic tissues (roots and shoots) was inhibited after the breaking of the inner seed coats. Nevertheless, caffeine increased more in such roots of the seedlings of decoated seeds than in roots of normal seedlings. 

Among the insect orders, tissues from Lepidoptera have attracted the most attention because of their historical importance as agricultural pests [48]. Insect cell lines have been established from a variety of tissues, mostly from undifferentiated ovarian or embryonic [49]. The undifferentiated nature of the embryonic tissue has made possible the establishment of continuous insect celllines from diploid tissues [49]. 

In the EST, two murine cell lines are used to assess teratogenic potential the embryonic D3 stem cell (ES) which represents the embryonic tissue and the 3T3 fibroblast cell which represents the adult tissue. The D3 cells are maintained in an undifferentiated stage in the presence of leukemia inhibiting factor (LIE), then released from LIE and allowed to form embryo bodies that differentiate into cardiomyocytes. The D3 and 3T3 cells are exposed to a range of concentrations of the test ingredient. After a 10-day... 

The embryonic tissue is overall dark and sloughing (necrotic in appearance). 

Enders, J.,T. Weller, and F. Robbins, Cultivation of the Lansing strain of poliomyelitis virus in cultures of various human embryonic tissues. Science, 1949.109 85-7. 

Early mammalian development has been hard to study because of two facts the ovum is very small, and a first priority is development of the placenta and of the layers of tissues that surround the embryo.308 311 312 This occurs in humans within the first week after fertilization. Both the trophectoderm and cells of the inner cell mass (Fig. 32-7) contribute to the extra embryonic tissues. 

Gelsolin is broadly expressed by cells of mesenchymal-epithelial origins both in the adult and in the embryonic tissues (Tanaka and Sobue, 1994 Teubner et al., 1994 Lueck et al., 1998 Arai and Kwiatkowski, 1999) (Spinardi and Witke, unpublished observation). Cytoplasmic gelsolin is highly expressed in platelets, macrophages and neutrophils, (Witke et al., 1995 Barkalow et al., 1996) but also in smooth muscle cells and osteoblasts (Spinardi and Witke, unpublished observation). However, muscle cells are the major source of the secreted plasma gelsolin (Kwiatkowski et al., 1988). 

John F. Ender (1897-1985), Thomas H. Weller (1915- ), and Frederick C. Robbins (1916- ) publish Cultivation of Polio Viruses in Cultures of Human Embryonic Tissues. The report by Enders and coworkers is a landmark in establishing techniques for the cultivation of poliovirus in cultures on non-neural tissue and for further virus research. The technique leads to the polio vaccine and other advances in virology. 

In January, 1983 a panel of scientists from 21 countries examined the claims of longer term deleterious effects on land, wildlife and humans of Vietnamese wartime exposure to herbicides (ref. 128c). The birth defects reported most frequently were those also associated with 2,4,5-T animal experiments. They included cleft palate, hare lip and missing limbs, e.g. muscular-skeletal defects, and incomplete closure of embryonic tissue leading to neural and spinal defects.-... 

Abbott BD, Bimbaum LS, Dilberto JJ. 1996. Rapid distribution of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) to embryonic tissues in C57BL/6N mice and correlation with palatal uptake in vitro. Toxicol Appl Pharmacol 141 256-263. 

Neuronal embryonic tissue Neuronal Parkinson s disease... 

A comparison between insect and mammalian cell culture technology shows various similarities and differences. Due to the fact that insect cell lines typically derive from specific organs or non-differentiated embryonic tissues, the same cell line can proliferate in suspension or in adherent manner (in monolayer). This versatility in growth mode, which contrasts with most mammalian cell lines, increases the choices of bioreactor types and culture strategies for production. Contact inhibition shown by various mammalian cell lines is low or absent for insect cells, and they tend to aggregate in suspension or in adherent cultures. 

Studies on the origin and development of the cellular elements of the blood and the so-called endothelial cells which line the blood vessels in the normal embryo are peculiarly difficult on account of the important r61e that wandering mesenchyme cells play in these processes. The problem is also further confused by the perplexing mixture of cells of different origin brought about by the early established circulation of the body fluids. The development of no other embryonic tissue is so disturbed by mechanical and physical conditions. 

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