an increase in the number of cells is called hyperplasia.
an increase in the number of cells is called hyperplasia.
an increase in the number of cells is called?
hyperplasia
synovial hyperplasia (an increase in cell number) is a typical feature of the autoimmune disease called rheumatoid arthritis (ra). during the progression of this disease the synovial membrane becomes a place where constant inflammatory processes take place, which can eventually lead to cartilage damage and joint destruction and deformation. due to the changes in proliferative and apoptotic processes the total number of cells increases in the synovium, and significantly increases also the number of fibroblast-like synoviocytes. these cells, together with other immune cells such as macrophages, lymphocytes, neutrophils, mast cells, dendritic cells and platelets, create an inflammatory environment in the synovium, attract more immune cells to the damaged place and thus contribute to the joint destruction.
fibroblast-like synoviocyte
humans are the only species known to keep ghrelin-producing ε-cells in the pancreas into adulthood. as a result, there are difficulties to study this cell type in adults since it can only be observed in the human pancreas. during the weeks 15-26 of the fetus during development, ε-cells compose about 10% of the islet cells, but following birth, their composition decreases to only 1% of adult islet cells. estimates of the average number of ε-cells per islet in adults vary in number with differing results. one study found that there are about 3 to 5 ε-cells present in each islet of the adult pancreas, which includes a total of about 1,000 islets. another study observed an average of 12±1.2 ε-cells per islet. in adult pancreas samples, they are observed to be round or oval shaped and remain localized on the mantle of the islets in different amounts, both in clusters and or single cells. in mice, ε-cells are present in the pancreatic islets and stomach during development, but are found strictly in the stomach after birth. in both humans and mice, results have varied on whether or not ghrelin is co-localized with other hormones in stages of adulthood or development. because of the scarcity of ε-cells in an adult pancreas, it is predicted that they do not continue to produce large amounts of ghrelin that circulates throughout the body. the human adult pancreas has an ε-cell composition of about 0.13 grams. sex and age do not affect the average number of ε-cells in islets. however, an inverse relationship between bmi and number of ε-cells is noted: as body weight increases, ε-cells decrease in number. loss of these cells due to increase in bmi leads to an increase in insulin secretion, and increased risk of apoptosis and inflammation in pancreatic islets. cell membrane receptors in adult ε-cells include short-chained fatty acid receptor ffar3, g protein–coupled bile acid receptor 1 (gpcr), interferon-α and interferon-β receptor subunit 1, interferon-γ receptor 2, a receptor known for its regulation of immunoglobulin g uptake, plasminogen receptor, and a cd320 receptor. the variety of receptors allow hormones, nutrients, lipids, and cytokine ligands to bind. the primary cellular metabolic pathway factor present in ε-cells are members that compose the fatty acid metabolism pathway, acsl1. acsl1 is an enzyme involved in the first step of fatty acid oxidation, and this pathway functions in this islet cell specifically to modify ghrelin acyl modification. transcription factors that are necessary ε-cell maturation and preservation are numbered to a total of 366. the functions of each individual transcription factor have not yet been studied.
epsilon cell