Shika Kiso Igakkai zasshi = Japanese journal of oral biology最新文献

Many growth factors are known to play important roles in the early wound healing process. However, their roles in the subsequent scar formation phase are relatively unexplored. The aim of this study is to investigate how these factors affect DNA and collagen synthesis by scar fibroblasts in the scar formation process. Experimental wounds were made by excising palatal mucosa of eight-week-old SD rats. One month later, immature scar tissues were secured from the palate and scar fibroblasts (SF) were obtained from explant cultures of these tissues. Normal fibroblasts (NF), used for control, were obtained from palatal mucosa of untreated animals by the same culture procedure. SF had more slender shape than NF in stationary phase. SF showed longer doubling time, higher collagen synthesis and relatively higher type III collagen formation compared with NF. PDGF and EGF stimulated [3H] Thymidine uptake less effectively in SF than in NF. TGF-beta had no effects on [3H] Thymidine uptake when it was added alone. However, when TGF-beta was administrated in combination with EGF, the EGF-induced stimulation in DNA synthesis was suppressed dose-dependently. TGF-beta stimulated collagen synthesis more effectively in SF than in NF. These data may explain the reason for the accumulation of collagen and the increase in cell number during the scar formation process.

Both phenytoin (PHT) and glucocorticoid (GC) have been reported to be an effective teratogen for the production of cleft palate. The authors suggest the possibility that a part of GC-receptor to which PHT competitively bind (common receptor with PHT), participate in the production of cleft palate. In the present study, as one of the studies for the elucidation of the mechanism of cleft palate induction with PHT, we investigated the PHT-receptors and its relation with GC in the lung tissue of mice, which were either sensitive (CF1) or resistant (C57BL/6) to PHT or GC. Scatchard analysis of the specific binding of 14C-PHT to the cytosol protein revealed that the total capacity of PHT-receptor for CF1 (1,571 fmole/mg protein) was much greater than that for C57BL/6 (994 fmole/mg). The value of the Kd's for these strains, however, were 18.1 and 16.5 nM, respectively, indicating the absence of any great difference between both strains. The capacity of the common receptors with GC for CF1 (236 fmole/mg) was greater than that for C57BL/6 (126 fmole/mg). But, the value of the Kd's for these strains were 5.4 and 3.1 nM, respectively, indicating the absence of a great difference between the strains. The analysis indicated that the lung tissue cytosols of both strains also contain the proper receptor for PHT, which is in a much greater amount than that of the common receptor.(ABSTRACT TRUNCATED AT 250 WORDS)

Bacteroides gingivalis were serologically investigated by the immunodiffusion technique using autoclave-extracted antigens and antisera against whole cells. Fifteen strains of B. gingivalis used in this study, were classified in two distinct serological groups. Eleven strains include strain 381, ATCC 33277 were classified Group A and four strains include strain Su63 were classified in Group B. The group specific antigens from B. gingivalis strain 381 (Group A) and Su63 (Group B) were partially purified from autoclave extracts by 75% ethanol precipitation and anion exchange chromatography, and were identified as polysaccharides composed of glucose (82.3%, 23.7%), rhamnose (7.1%, 12.7%), galactose (4.9%, 18.2%), mannose (2.3%, 1.7%), glucosamine (0.4%, 28.0%) and galactosamine (3.0%, 15.3%).

A role of a cation of glutamate compounds for their taste has not been well elucidated yet. In this experiment, the difference of taste quality of glutamate compounds which have a different cation was compared to reveal the role of cations in the glutamate compounds on their characteristics of taste. Monosodium L-glutamate (MSG), monopotassium glutamate (MPG) and monocalcium glutamate (MCG) were used. The preference test in rats revealed that the rate of drinking volume per day was not statistically different among MSG, MPG and MCG. In the next experiment, the conditioned taste aversion test was performed in rats, and rats were conditioned to hate to drink MSG, MPG and MCG respectively by pairing the intraperitoneal injection of LiCl. In the MSG conditioned animals, the drinking rate of MSG decreased, and that of MPG significantly increased, but that of MCG did not change. In the MPG conditioned animals, drinking rate of MPG was strongly depressed, but that of MCG tended to increase, and that of MSG did not change at all. In the MCG conditioned animals, the drinking rate of MCG decreased, but MSG and MPG did not change. The chorda tympani responses to 0.1 M MSG applied to the tongue surface was larger than those to 0.1 M MCG, and the responses to 0.1 M MPG were the smallest out of these three glutamate compounds. The nerve responses of the glossopharyngeal nerve to MSG, MCG and MPG were very similar to each other.(ABSTRACT TRUNCATED AT 250 WORDS)