Meikai Daigaku shigaku zasshi = The Journal of Meikai University School of Dentistry最新文献

Effect of alcohols (methanol, ethanol, propanol, butanol, and hexanol) on nerve growth factor (NGF)-induced neurite outgrowth from pheochromocytoma PC12h cells, a subclonal line of PC12, was studied. Although the addition of alcohol alone did not induce neurite development, both the NGF-induced increase in neurite length and the frequency of neurite-bearing cells were enhanced by alcohols. However, this stimulating effect of alcohols was detected only within a short time after NGF and alcohol had been added: differences in the average neurite length and in the frequency of neurite formation between the cells treated with NGF alone and those treated with NGF plus alcohol were not significant at 48 hours and 16 hours, respectively, after the start of treatment. The longer the carbon chain of the alcohol, greater enhancing effect on neurite formation. These results suggest that alcohols did not strengthen the final intensity of the NGF effect to elaborate neurites but rather shortened the time required for process formation in response to NGF by presumably increasing the fluidity of plasma membranes of PC12h cells.

Among several bioactive substances known as coupling factors, transforming growth factor-beta (TGF-beta), interleukin-1 (IL-1), and prostaglandin (PG) E1 and E2 increased not only the activity of alkaline phosphatase but also the rate of incorporation of 45Ca2+ into ROS 17/2.8 during a 3-day culture: the former two factors are known to be formed at the site where bone is resorbed, while PG's are known as one of the factors involved in bone resorption. Parathyroid hormone, another hormone that affects bone metabolism, elevated the incorporation of 45Ca2+ by and decreased the alkaline phosphatase activity of the cells. The facts indicate the possibility that the osteoblastic cells are involved in the transport of calcium ions when bones are being resorbed. On the other hand, when these osteosarcoma cells were cultured in DMEM containing ascorbate and beta-glycerophosphate, followed by staining with silver nitrate by the procedure of von Kossa, there appeared many groups of cells that were positively stained as dark brown spots. Cells were then cultured under the same conditions in the presence of radioactive calcium, and the radioactivity accumulated was measured. The result showed that the presence of both ascorbate and beta-glycerophosphate in the culture medium dramatically increased the accumulation of 45Ca2+. It appears from these facts that ROS 17/2.8 cells are capable of incorporating and/or accumulating calcium ion if they are cultured under appropriate conditions. These cells will probably be able to produce a calcified matrix in vitro.

Twenty-nine brands of dental casting nickel-chromium alloys made in Japan for small castings were analyzed by electron probe X-ray microanalyzer. Nickel-chromium alloys for metal-ceramic application were composed primarily of nickel, chromium, and molybdenum with the exception of one brand. Of the nickel-chromium alloys for inlay, crown, and bridgework applications, 11 of the 22 alloys were up to the standard of the Ministry of Welfare specifications. And additive metal elements of these alloys were molybdenum, iron, copper, manganese, aluminum, silicon, tin, indium, silver, titanium, and gallium.

We analyzed statistically two thousand orthodontic patients in Meikai University Hospital (formerly Josai Dental University Hospital) who have undergone treatment since the establishment of the hospital (1970-1985). By classifying the data in various ways, we obtained the following statistics; 1) The number of new patients increased quickly after the first class graduated from our university; 2) The number of patients from six to fifteen years old was the largest, with the peak being nine years old; 3) For the time of the first visit, many new patients came during spring and summer vacations, and a few junior high school and high school students came just season before taking their entrance examination; 4) The female sex predominated in most age groups; however, among patients in their twenties, the male sex was predominant, and in recent years the male ratio tended to increase; 5) Most patients came from a radius of less than 20 km from the hospital (mostly from along Tohbu railway line), with few from beyond 30 km; 6) Anterior crossbite and anterior crowding cases were many, particularly, young patients comprised many of the anterior crossbite cases; and in adult patients large overjet cases increased with the advance of age.

In order to study the difference in the path between the incisal point and its tracers, which were LED or a magnet, for two types of mechanism used in ready-made simple mandibular movement recording apparatuses, we calculated their locations during the rotally opening or protrusion of the mandible in the sagittal plane. The movement of the LED tracer was larger than that of the incisal point during the rotally opening movement, and its magnification ratio increased with increased opening. During the protrusion, the difference in their movements was affected by the balance of the inclination of the condyle path and the incisal path, and the movement of the tracer expanded vertically but contracted horizontally as the inclination of the incisal path was increased. The movement of magnet tracer was larger than that of the incisal point during the opening movement, but its magnification ratio decreased as the degree of opening increased. During the protrusion, the horizontal movement of the tracer was smaller than that of the incisal point, and its magnification ratio decreased as the inclination of incisal path became smaller. Its vertical movement was similar to that of the incisal point.

In order to clarify the effects of androgens and insulin (Ins) on the growth and regeneration of bone in growing rats, and to examine the interaction of the two hormones on the bone growth and regeneration, I carried out both in vivo and in vitro experiments using male rats and clonal osteoblastic cells, respectively. In vivo: 1) Three week-old male rats were castrated, and one week after the castration two holes were drilled into their calvariae, followed by subcutaneous administration of 2 mg/kg of testosterone propionate (TP) and/or 20 mg/kg of cyproterone acetate (CPA). After the daily administration of the drugs for two weeks, the calvariae containing wound holes were isolated, and a soft X-ray photograph was taken. The area of the hole in the X-ray film was measured. The calcium (Ca) and the hydroxyproline (HP) contents and alkaline phosphatase (ALPase) activity in the wound and non-wound portions of the calvariae were also determined. 2) Streptozotocin (STZ, 80 mg/kg) was administered intravenously to immature male rats (25-day-old); and three days after the administration, wound holes were made in their calvariae. Ins (10 units/kg) and/or TP (2 mg/kg) were/was administered daily for two weeks starting two weeks after the operation. The length and weight of the femur, and the area of the hole of the calvariae seen in a soft X-ray photograph were measured. The Ca and HP contents in the wound portion, and serum Ca and phosphate (P) levels and ALPase activity were also determined. In vitro: Mouse clonal osteoblastic cells (MC3T3-E1) were incubated in alpha-MEM mudium containing 10% FBS or 0.1% BSA with or without 10(-9)-10(-6) M TP and/or 10(-9)-10(-6) M Ins, the number of cells was counted, and [3H] thymidine incorporation into the cells was assayed for assessment of DNA synthesis. ALPase activity of the cells was also assayed. The results obtained were as follows: 1. The reduction in the wound-hole area was significantly delayed after the castration and was accelerated by TP. This effect of TP was inhibited about 60% by the simultaneous administration of CPA, though this inhibition was not statistically significant. 2. The reduction in HP content of the wound portion by castration was inhibited by TP, and this effect was antagonized by CPA.(ABSTRACT TRUNCATED AT 400 WORDS)

Organic solvent extraction of three metanephrines (MNs) in supernatant and sediment fractions obtained by the addition of methanol to the whole saliva and liquid chromatographic analysis with voltammetric detection are described. Two milliliters of unstimulated whole saliva obtained from 13 healthy males was treated with chilled methanol to separate mucin clots. The mucin clots, supernatant, and whole saliva were then hydrolyzed at 98 degrees C for 40 minutes at pH 0.5-0.8. These hydrolyzed samples were subsequently brought up to pH 10.0 with a 6 N NaOH solution in 0.1 M borate buffer (pH 10.0), and then 5-HT and MNs were extracted into toluene: isoamylalcohol (3:2) from the basic phase. MNs in their organic phase were extracted back into 0.1 M acetic acid and used for the high-performance liquid chromatographic (HPLC) analysis. The supernatant fraction showed a higher distribution for MNs than the sediment and whole saliva fractions. The chromatographic profile obtained from the supernatant and the whole saliva fractions contained some serotonin in a pattern similar to that reported from urinary analysis. The use of methanol for the fractionation of saliva resulted in good differential determination of MNs and revealed their distribution in the three salivary fractions. It is attractive to speculate that patients undergoing restorative treatment possibly manifest their anxiety by salivary excretion containing serotonin and MNs. These compounds in saliva may be useful markers of emotional responses.

In order to clarify the relationship between selected oral environmental factors and caries type in infants, we analyzed three parameters, salivary pH, salivary buffer capacity, and Cariostat, and tested their association with caries type. As a result, we obtained a significant relationship between the caries type and salivary buffer capacity, and also between the caries type and the Cariostat. The severity of caries increased with an increase in caries activity level measured by Cariostat, while it decreased with an increase in salivary buffer capacity (p less than 0.05). The occurrence rates of severe caries types were high under the condition of both low salivary buffer capacity and high acid productivity of dental plaque.

Dermoid cyst or epidermoid cyst of the oral cavity usually occurs in the floor of the mouth. We encountered a 21-year-old woman who had developed epidermoid cyst in the oral floor. Since infancy she had been aware of a swelling in the oral floor. Recently, the swelling began to grow larger gradually. The lesion was excised under general anesthesia by intraoral approach. The swelling was spherical in shape, measured 50 x 45 x 40 mm in size, and weighed 40 g. Histopathological examination revealed keratinized, stratified squamous epithelium on the cyst wall and marked deposition of melanin at the base of the epithelium.

Extracellular ATP increased the cytosolic Ca2+ level of pheochromocytoma PC12h cells, a subclonal line of PC12. This increase in Ca2+ was predominantly due to an increased Ca2+ influx rather than to intracellular mobilization of the ion. One half of the maximal increase in Ca2+ level was observed with an ATP concentration of approximately 1 microM. ADP also induced an increase in cytosolic Ca2+ but to a lesser extent than ATP, whereas neither AMP nor adenosine showed such effect. ATP also modulated the nerve growth factor (NGF) action on these cells: ATP enhanced the NGF-induced neurite outgrowth, although ATP alone did not cause neurite development. After 3-day treatment the average neurite length of the cells treated with both NGF and ATP was about 1.5-fold greater than that of the cells treated with NGF alone. ADP also showed similar effect as ATP, while AMP did not. The ATP concentration that gave one half of the maximal enhancement of the outgrowth was estimated to be 180 microM. Enhancement of NGF-induced neurite outgrowth by ATP was also observed in serum-free cultures. The enhancing effect on NGF-induced neurite outgrowth was also specific for ATP. These results thus indicate the presence and involvement of P2-type purinergic receptors on PC12h cells in the ATP effects, and suggest a novel function of extracellular ATP as a modulator of hormonal actions.