* Hyaluronic acid secretion by synoviocytes alters under cyclic compressive load in contracted collagen gels.
- Knee osteoarthritis is a degenerative disease of diarthrodial joints. Biomechanical factors are considered as risk factors for the disease, the knee joint being normally subject to pressure. Some studies have examined the biomechanical environment of the knee joint in vitro. The aim of this study was to establish a culture model to mimic the knee joint environment. As a first step, synoviocytes induced contraction of three-dimensional collagen gels. Next, contracted collagen gels containing synoviocytes underwent cyclical compression ranging from 0 to 40 kPa at a frequency of 1.0 Hz for 1.5, 3, 6 and 12 h using the FX-4000C™ Flexercell(®) Compression Plus™ System. RNA in collagen gels was extracted immediately after compression and mRNA expression levels of HAS genes were analyzed by quantitative RT-PCR. Culture medium was collected 48 h after compression and analyzed by agarose gel electrophoresis and cellulose acetate electrophoresis. Synoviocytes in contracted collagen gels were stimulated by cyclic compressive load. Long-term compressive stimulation led to the production of higher molecular weight hyaluronic acid, whereas, short-term, compressive stimulation increased the total amount of hyaluronic acid. Furthermore, mRNA expression levels of both HAS-1 and HAS-2 were significantly higher than without compression. Taken together, using this gel culture system, synoviocytes synthesized higher molecular weight hyaluronic acid and produced large quantities of hyaluronic acid through up-regulation of HAS gene expression. Therefore, the contracted collagen gel model will be a useful in vitro three-dimensional model of the knee joint.
=>初めて, 最初の, 第一の, はじめに, 最初, 第1
Overview of noun first
The noun first has 6 senses (first 4 from tagged texts)
1. (9) first, number one -- (the first or highest in an ordering or series; "He wanted to be the
first")
2. (5) first, number one, number 1 -- (the first element in a countable series; "the first of the
month")
3. (1) beginning, commencement, first, outset, get-go, start, kickoff, starting time, showtime,
offset -- (the time at which something is supposed to begin; "they got an early start"; "she knew
from the get-go that he was the man for her")
4. (1) first base, first -- (the fielding position of the player on a baseball team who is stationed
at first of the bases in the infield (counting counterclockwise from home plate))
5. first, first-class honours degree -- (an honours degree of the highest class)
6. first gear, first, low gear, low -- (the lowest forward gear ratio in the gear box of a motor
vehicle; used to start a car moving)
Overview of adj first
The adj first has 6 senses (first 5 from tagged texts)
1. (232) first -- (preceding all others in time or space or degree; "the first house on the right";
"the first day of spring"; "his first political race"; "her first baby"; "the first time"; "the
first meetings of the new party"; "the first phase of his training")
2. (61) first, 1st -- (indicating the beginning unit in a series)
3. (4) inaugural, initiative, initiatory, first, maiden -- (serving to set in motion; "the
magazine's inaugural issue"; "the initiative phase in the negotiations"; "an initiatory step toward
a treaty"; "his first (or maiden) speech in Congress"; "the liner's maiden voyage")
4. (4) beginning, first -- (serving to begin; "the beginning canto of the poem"; "the first verse")
5. (3) first, foremost, world-class -- (ranking above all others; "was first in her class"; "the
foremost figure among marine artists"; "the top graduate")
6. first -- (highest in pitch or chief among parts or voices or instruments or orchestra sections;
"first soprano"; "the first violin section"; "played first horn")
Overview of adv first
The adv first has 4 senses (first 4 from tagged texts)
1. (58) first, firstly, foremost, first of all, first off -- (before anything else; "first we must
consider the garter snake")
2. (40) first, for the first time -- (the initial time; "when Felix first saw a garter snake")
3. (9) first -- (before another in time, space, or importance; "I was here first"; "let's do this
job first")
4. (4) foremost, first -- (prominently forward; "he put his best foot foremost")
--- WordNet end ---