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General Introductory Topics
Published in Vadim Backman, Adam Wax, Hao F. Zhang, A Laboratory Manual in Biophotonics, 2018
Vadim Backman, Adam Wax, Hao F. Zhang
The basal lamina, on the other hand, is synthesized by parenchymal cells. In particular, all epithelial cells (without exception) produce basal laminae that underlie all epithelia. In fact, some have suggested that it is the basal lamina–producing property of epithelial cells that is the principal, if not the only, common property of all epithelia. The basal lamina separates the epithelial lining from the underlying connective tissue. The main constituent of the basal lamina is collagen type IV. Other components include laminin and proteoglycans. While the interstitial matrix may have quite a few mesenchymal (e.g., fibroblasts) and inflammatory cells interspersed in it, basal lamina are completely acellular.
Articular Cartilage Development
Published in Kyriacos A. Athanasiou, Eric M. Darling, Grayson D. DuRaine, Jerry C. Hu, A. Hari Reddi, Articular Cartilage, 2017
Kyriacos A. Athanasiou, Eric M. Darling, Grayson D. DuRaine, Jerry C. Hu, A. Hari Reddi
Laminins were initially identified as noncollagenous, large molecular polypeptide chains (220 and 440 kDa) of the basement membrane of a transplantable mouse tumor (Timpl et al. 1979). Laminins are heterotrimeric extracellular glycoproteins consisting of α, β, and γ chains that can self-bind to form lattice structures, while also having domains to bind collagen, integrins, and proteoglycans. In chondrocytes, laminin 1 (LN-1) binds to β1 integrin, specifically integrin α6β1 (Durr et al. 1996). Laminins are present in most tissues and help to resist tensile forces in the basal laminae through the production of their lattice structural network.
Tissue engineering and regenerative medicine
Published in Ronald L. Fournier, Basic Transport Phenomena in Biomedical Engineering, 2017
The basal lamina is a continuous mat-like structure of ECM materials that separates specific cells, such as epithelial, endothelial, or muscle, from the underlying layer of connective tissue. The basal lamina consists of two distinct layers, the lamina rara* directly beneath the basal membrane of the specific cells above and the lamina densa† just below the lamina rara. Found below the two layers of the basal lamina is the collagen-containing lamina reticularis that connects the basal lamina to the connective tissue that lies below it. All three of these layers together constitute what is known as the basement membrane (see Figure 10.3). The basal lamina consists primarily of type IV collagen, proteoglycans, such as those formed from heparan sulfate, and the glycoprotein laminin.
Effects of X-ray application on infertility in new-born rats
Published in Radiation Effects and Defects in Solids, 2023
Salih Çibuk, Handan Mert, Nihat Mert, Oğuz Tuncer, Fikret Altındağ, Kamuran Karaman, Uğur Özdek, İsmet Meydan
In Figure 1, it was observed that the testicular tissues were have normal histological structure in the control group. In the control group, there were normal spermatogenic serial cells in the germinal epithelium and Sertoli cells resting on the basal lamina. Sperm cells were located in the lumen of the normal and seminiferous tubules. Leydig cells were in normal structure and were in the interstitial area. Group 2, 3 and 4 compared with the control, it was observed that the number of germinal epithelial cell layers of the seminiferous tubule decreased, atrophy in the seminiferous tubules, shrinkage of the seminiferous tubules and a decrease in the sperm cells in the lumen (severe). Group 5 showed moderate atrophy and shrinkage in seminiferous tubules, decrease in cell number in lumen, and decrease in germinal epithelial cell layer.
Maternal bisphenol A exposure disrupts spermatogenesis in adult rat offspring
Published in Journal of Toxicology and Environmental Health, Part A, 2019
Patricia De Campos, Isabela M. Oliveira, Janaina Sena de Souza, Rodrigo Rodrigues Da Conceição, Gisele Giannocco, Maria I Chiamolera, Magnus R.Dias-Da Silva, Marco A. Romano, Renata Marino Romano
The testes were fixed in Bouin’s solution for 8 h, treated with alcohol, embedded in paraffin and prepared as stained laminas with periodic-acid Schiff (PAS). The linear morphometry from the seminiferous tubules was analyzed by determining the tubular diameter (measured from the basal lamina to the basal lamina in the opposite direction), the seminiferous epithelium (from the basal lamina to the neck of the elongated spermatids) and the luminal diameter, as previously described (Romano et al. 2010). These measurements were performed using the software tpsDig2 version 2.10 (Available from http://life.bio.sunysb.edu/morph).
It's not just about protein turnover: the role of ribosomal biogenesis and satellite cells in the regulation of skeletal muscle hypertrophy
Published in European Journal of Sport Science, 2019
Matthew Stewart Brook, Daniel James Wilkinson, Ken Smith, Philip James Atherton
Skeletal muscles cells are multinucleated but terminally differentiated cells (Heron & Richmond, 1993). However, skeletal muscle also possess a residual pool of resident muscle stem cells – SC (Mauro, 1961). Unlike their sub-sarcolemma Myonuclei counterparts, SC are located in the extracellular matrix between the sarcolemma and the basal lamina and in being a type of stem cell (unlike myonuclei) (Bintliff & Walker, 1960), SC possess mitotic potential. The physiological role of SC is thought to be the provision of “new” nuclei to existing myofibers, supporting transcriptional capacity, while at the same time ensuring through division, sustainment of an extracellular SC population. Upon activation, SC exist quiescence and enter the cell cycle where they can proliferate as myoblasts and potentially terminally differentiate. A population of these cells will undergo asymmetric cell division where by one daughter cell remains quiescent maintaining SC number and a continued source of myonuclei (Moss & Leblond, 1971; Troy et al., 2012). The contended role of SC in the regulation of hypertrophy was derived from the concept that each nuclei of a multi-nucleated myofibre appears to synthesise protein for a close vicinity domain (Figure 2) (Gundersen, Sanes, & Merlie, 1993; Hall & Ralston, 1989) and that this karyoplasmatic ratio is held constant (Allen, Roy, & Edgerton, 1999). Obviously, this means that as a muscle hypertrophies, the fixed nuclei content of terminally differentiated muscle cells essentially becomes “diluted” to a point that a new source of nuclei is needed to support the transcriptional requirements of supporting a larger myofiber volume. Therefore, the potential role for SC in regulating and/or limiting muscle hypertrophy has many foundations that warrant detailed consideration.