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The Role of Eicosanoids in Menstruation and Disorders of Menstruation
Published in Murray D. Mitchell, Eicosanoids in Reproduction, 2020
Early studies measured the amounts of PG in tissue which had been obtained at operation and rapidly immersed in alcohol to prevent degradation of the PG. Such studies were presumed to reflect the de novo synthesis of PGs stimulated by the trauma of tissue collection.18 Levels of PGF2α were found to rise in the luteal phase of the cycle,12,13 whereas PGE2 levels did not change. Persistent proliferative endometrium taken from women in the expected luteal phase, but in whom ovulation had not occurred, had the same levels of PGF2α and PGE2 as normal proliferative tissue.19 Similar levels of PG could be induced in postmenopausal women by administration of exogenous estradiol and/or progesterone.20 These studies suggested that progesterone enhanced the capacity of endometrium to synthesize PGs in response to the trauma of tissue collection, but indicated that the control of PGF2α synthesis was different from that of PGE2 synthesis. Similarly, whole tissue maintained in organ culture was found to release more of the former than proliferative tissue.21,22
Prolactin Receptors in Normal Tissues and in Animal Models for Breast Cancer
Published in Nagasawa Hiroshi, Prolactin and Lesions in Breast, Uterus, and Prostate, 2020
Paul A. Kelly, David Gould, Hiroaki Okamura, Jean Dijane
In vitro techniques have been employed to examine hormonal factors important in human breast tumor growth. Results vary with the particular cell line tested, and with culture conditions. Among these techniques is organ culture. This technique has several advantages since it lends itself to the testing of biopsy specimens and it permits hormonal manipulation of cancer cells in situ. This is important since cells may respond differently when attached to native tissue substrates compared to plastic or glass.153
The fetal period
Published in Frank J. Dye, Human Life Before Birth, 2019
During much of the twentieth century, researchers extensively used cell culture in biomedical research. Additionally, tissue, organ, and embryo culture were also used. The formation of an organ during development is called organogenesis. A certain amount of organogenesis could occur in culture; for example, the development of mouse tooth germs (embryonic mouse teeth) would undergo a certain amount of organogenesis in vitro (i.e., in culture); however, organ culture was limited by size restrictions related to the rate of diffusion of nutrients into the volume of the organ or organ fragments. Embryo cultures, especially of mouse embryos, were limited to early development because mammalian embryos must at some point implant into a uterus, so although these embryo cultures provided good insight into early mammalian development, development beyond the blastocyst stage would be hidden from view. Cell and tissue cultures for most of the twentieth century were generally two-dimensional (2D) cultures (see Figure 9.9), as the cells or tissues grew as a flat layer on their glass, or, increasingly, plastic, substratum. A relatively recent innovation involves the use of 3D cultures (see Figure 9.10). This is a more natural environment for the cultures, as cells grow in vivo (i.e., within the organism) in three dimensions.
Effects of a prostaglandin F2alpha derivative glaucoma drug on EGF expression and E-cadherin expression in a corneal epithelial cell line
Published in Cutaneous and Ocular Toxicology, 2020
Yukihisa Takada, Osamu Yamanaka, Yuka Okada, Takayoshi Sumioka, Peter S. Reinach, Shizuya Saika
The current cell culture experiment showed that the travoprost treatment up-regulated the expression of EGF in association with increases in cell proliferation and this was cancelled by the addition of an Erk inhibitor. In the organ culture, the addition of travoprost to the medium up-regulated the phosphorylation of EGFR and Erk as well as b-catenin, and the activation of these components was reversed by PD168393. In the present organ-culture experiment, similar increases occurred in cell proliferation. This response was associated with the phosphorylation of Erk along with rises in Ki67staining whereas PD168393 blocked these changes. It currently remains unclear whether increased cell proliferation is favourable for tissue homeostasis. Cell proliferation-promoting signalling generally has a negative impact on cell differentiation16. Epithelial cell differentiation is critical for the maintenance of tissue barrier function. Thus, the acceleration of cell proliferation in the epithelium may lead to the breakdown of its barrier function. Therefore, we evaluated the expression pattern of E-cadherin in corneal epithelial cells following exposure to travoprost in vitro and under organ-culture conditions.
Probing paracellular -versus transcellular tissue barrier permeability using a gut mucosal explant culture system
Published in Tissue Barriers, 2019
E. Michael Danielsen, Gert H. Hansen
Organ culture of intestinal tissue was performed essentially as described previously.23 Briefly, after removal from the animals, jejunal segments (~20 cm) were quickly cut open longitudinally and placed in ice-cold RPMI medium. Mucosal tissue specimens weighing ~0.1 g were excised with a scalpel and transferred to metal grids in organ culture dishes to which 1 ml of RPMI medium was added. The dishes were placed in an incubator kept at 37°C and subjected to 15 min of preincubation without any additions to the medium. SDS or EDTA was added to the culture medium at a final concentration of 0.05%. The following fluorescent probes for cellular uptake were added together with the PEs: LY (0.5 mg/ml), TRD3 (0.05 mg/ml), OGD10 (0.25 mg/ml), TRD70 (1.25 mg/ml), FM 1–43 (0.01 mg/ml) and FM 4–64 (0.01 mg/ml).
Intervertebral Disc Degeneration Models for Pathophysiology and Regenerative Therapy -Benefits and Limitations
Published in Journal of Investigative Surgery, 2022
Yidian Wang, Jihe Kang, Xudong Guo, Daxue Zhu, Mingqiang Liu, Liang Yang, Guangzhi Zhang, Xuewen Kang
The organ culture model is a relatively complex system, but it can still study specific pathogenic factors and treatment strategies in a controlled environment. In recent years, a variety of organ culture systems have been reported, and the development of bioreactor has injected new vitality into IDD research [53–56]. For organ culture, it is very important to obtain biological tissue with high cell viability and sufficient number of cells, especially for human IVD. Some studies have found that it is feasible to collect IVD within 48 hours after death [57]. The second is how to provide continuous nutrient supply, which can be achieved by increasing the circulation system of culture medium [58, 59]. In addition, increasing the volume ratio of medium to tissue can also meet the short-term demand for nutrients. However, this requires higher integrity of CEP on both sides [60]. Another major challenge comes from the hypertonic environment formed by PGs, which is essential for maintaining the moisture, height, and mechanical function of IVD [31, 61, 62]. Unfortunately, it will lead to water absorption and swelling of IVD when cultured in vitro, and this phenomenon is related to the integrity of the CEP. When bilateral CEP is retained, the expansion will be significantly smaller [63–65]. In addition, compared with the preservation of bilateral CEP, removal of CEP or preservation of part of vertebrae will lead to excessive death of IVD cells [65]. Therefore, it is very important to keep the CEP intact when separating IVD tissue. At present, a variety of IVD degenerative organ culture models have been established, which are based on the pathogenesis of IDD and realized by different methods and combinations (Table 1).