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

About apatite produced with a silicahydro gel method using calcium nitrate (group I) or calcium chloride (group II) and a gelatin gel method by use of calcium nitrate (group III) or calcium chloride (group IV), the formative volume as well as the formative condition of a periodic-layered precipitate (Liesegang ring), the pH measurement, calculation of Ca/P ratio, an estimation of the chlorine ion, morphological observation with a scanning electron microscope, qualitative analyses by X-ray diffraction (identification, crystallite size, lattice imperfections, lattice constants) and the composition analysis by infrared absorption spectroscopy were carried out to elucidate the formation of apatite using the gel method. The result showed that there were no distinct differences between group I-II and group III-IV, and it is suggested that it is possible to form satisfact fluorapatite with a gel method using calcium chloride as well as calcium nitrate.

The cell growth kinetics in response to a burned injury was studied in the lip mucosal epithelium of C3Hf/He mice by using a pulse labelling method with 3H-thymidine for microautoradiography. Basal cells were labelled immediately after injury, and the mice were sacrificed for preparation at various intervals of time thereafter. The variations in frequencies of the labelled cells and mitosis were observed in their neighbors by the injury and also in untreated cells for comparison. The results of the observation are summarized as following. 1) The cell cycle time of the neighbor basal cells was estimated as 25.4 hrs, being about 36% shorter than that of 39.5 hrs in untreated cells. 2) The transition of the basal cells towards the upper layers of the epithelium was found to occur earlier (about 6 hrs after injury) in the neighboring cells in contrast to the transition time (20 hrs after labelling of untreated cells. But there was no difference in the rate of transition between the neighbors and the untreated cells. 3) The turnover time of the lip epithelial cells, which was measured by the peak to peak time difference in labelling index between basal and granular layers, was about 2 days and became about half of the time (4 days) for untreated cells. 4) The labelling index was found to form a peak first in the neighborhood at a distance of 200-300 cells away from the edge of the injury. Then, this peak moved centripetally toward the edge of burn, as time passed.

The localization of fibronectin (FN) in the initial stage of periodontal ligament formation was examined immunohistochemically. This period was divided into four stages with respect to epithelial-mesenchymal interactions. FN was observed on the cell membrane of the follicular mesenchymal cells near the basement membrane of the epithelial root sheath outer layer (stage I). In the stages of contact between follicular mesenchymal cells and the epithelial cells of the outer layer (stage II) and those penetrating the intercellular space of the discontinuous epithelial cells of the root sheath (stage III), FN was observed on the cell membrane of follicular mesenchymal cells which was in contact with epithelial cells. Follicular mesenchymal cells which were in contact with the FN rich dentin surface had well-developed cytoplasmic organelles (stage IV). Nonstriated fibrils were seen close to the projection of mesenchymal cells elongating toward the dentin surface, and were oriented parallel to the projection. FN in the small fibrils was clearly observed in the area connected to the mesenchymal cells. The reaction of FN was less in the area where collagen fibrils were organized into bundles. A dense amount of FN was seen where the periodontal ligament crossed into the dentin surface collagen. It is considered that FN plays an important role in follicular mesenchymal cell penetration of the increasing intercellular space between epithelial cells, the differentiation into the fibroblast at the dentin surface, the formation and arrangement of the periodontal ligament, and the attachment of the periodontal ligament to the dentin surface.

Caerulein and cholecystokinin (CCK) injection (i.v.) into rats caused about a 2.3- and 1.9-fold increase in serum amylase activity within 2 h, respectively. The increase of amylase activity in the serum caused by pilocarpine or isoproterenol injection (i.p.) was only of parotid-type amylase. Caerulein or CCK markedly increased pancreatic-type amylase, and significantly increased parotid-type amylase in the serum.

Two-hundred and seventy-five epidemiologically unrelated herpes simplex virus type 1 (HVS-1) strains isolated from seven areas (Sapporo, Akita, Nagoya, Kyoto, Tottori, Kagawa and Kurume) in Japan were compared with the standard laboratory strain F, based on cleavage analysis of HSV-1 DNAs with three restriction endonucleases, BamHI, KpnI and SalI. The results obtained were as follows: 1) Using gains and losses of 19 cleavage sites selected from 114 sites, the total of 275 strains could be classified into 87 distinct cleavage patterns. Also, it was found that the isolates were clustered in four predominant patterns, the pattern 27, 6, and 76, containing 62, 24, 15 and 12 strains, respectively. 2) There were highly significant differences in the incidence of isolates classified into the pattern 27 that were obtained in Kagawa as compared with those in Sapporo, Akita, Nagoya and Kurume, and those in Tottori as compared with those in Sapporo, Akita, Nagoya and Kurume. There was also a significant difference in the incidence of isolates classified into the pattern 76 that were obtained in Kagawa as compared with those isolated in Kurume. 3) There were significant correlation coefficients (p less than 0.05) between some stets, e.g. loss of the site between A and A' and gain of a site in A cleaved with BamHI, in every pair of 18 cleavage sites. 4) The phylogenic tree of 87 patterns based on genomic similarities of the Japanese HSV-1 isolates was established, and it was considered that HSV-1 isolates from Japanese could be phylogenetically classified into two to six major groups. These results suggest that HSV-1 strains have mutated and evolved independently by the transmission of the viruses among geographically separated hosts over an extremely long period, and that the genetically characteristic variants have accumulated and persisted in the present Japanese population.

This is a basic study designed to elucidate the correlation between the different cranial dimensions to the lengths of the hard palate and retropalatal space in dry skulls. A craniometric analysis is reported for 89 adult Japanese dry skulls. Eight dimensions were measured. The results of the study revealed that the cranial size has statistically significant correlations to the length of the hard palate and retropalatal space. It also revealed that a different pattern of correlation exists in the male and the female skulls. This study is probably the first of its kind. The results will serve as a basis for clinical research dealing with the anatomy and physiology of the palate and velopharyngeal port (velum pharyngeal musculature and pharyngeal aperture), which are concerned with normal speech formations.

The present study was designed to investigate the mechanism of gingival vasodilatation induced by electrical stimulation of the inferior alveolar nerve (IAN) in cats. A total of 55 young cats (2-4 kg) were anesthetized with pentobarbital sodium (30 mg/kg, i.v.). After IAN was surgically exposed, gingival blood flow (GBF) was continuously measured with the noninvasive technique of using a laser Doppler velocimeter (LDV). The systemic blood pressure was monitored during the experiment. Electrical stimulation of the distal end of the cut IAN led to a GBF increase with no alteration of the blood pressure in guanethidine treated cats. These increases were dependent on both the stimulus intensity (20-80 V) and the stimulus duration (0.2-5 sec). The GBF increases observed were reproducible for 100 min, when a resting period of 10 min was allowed between stimulations. The GBF increase by electrical stimulation of IAN was significantly inhibited by 66.8 +/- 7.3%, 51.1 +/- 3%, 37.8 +/- 4.6% (mean +/- S.E.M.) after i.v. injection of (D-Pro2, D-Try7,9)-substance P, triplennamine or methysergide, respectively. I.v. injection of atropine, propranolol, hexamethonium or cimetidine, on the other hand, had no effect on the GBF increase by electrical stimulation of IAN. These results suggest that gingival vasodilatation following electrical stimulation of IAN in cats is initiated by the peripheral release of substance P from sensory nerves, and that the substance P released, in turn, stimulates the mast cells to release histamine or serotonin which causes the vasodilatation.