Goultschin J, Gazit D, Bichacho N, Bab I
. Changes in teeth and gingiva of dogs following laser surgery: a block surface light microscope study
[Internet]. Lasers Surg Med 1988;8(4):402-8. Publisher's VersionAbstract
The effect of laser surgery on tissues of the periodontal apparatus was studied histologically in dogs using block surface light microscopy, a novel microscopical method. With this approach, changes in the hard and soft tissue components were concomitantly demonstrated; the method enabled preservation of the in situ relationship between these components. Following laser surgery, healing in the gingiva was delayed as suggested by the presence of epithelial ulcerations and dense inflammatory infiltrate. In the enamel and cementum the application of laser resulted in crater-like defects that could be avoided only partially by insertion of a tinfoil shield into the gingival sulcus. In the vicinity of the cementoenamel junction these defects were filled with epithelium or periodontal ligament fibers; the close proximity of the hard and soft tissues at the defect sites suggested occurrence of new attachment. Enamel defects located coronal to the gingiva contained bacterial plaque. These histologic results do not demonstrate any substantial advantage of laser over conventional knife gingivectomy. Such advantage may be accomplished with the design of a special intraoral handpiece and further experiments.
Goodman-Topper ED, Gazit D, Eidelman E
. Tooth-germ sequestration as a sequela of chronic periapical inflammation of the primary predecessor
[Internet]. ASDC J Dent Child 1988;55(6):455-8. Publisher's VersionAbstract
In this case the permanent successor was so radiographically indistinct due to the inflammatory process that this three-year-old Arab boy might have been classified as having congenital absence of the mandibular left first premolar, if the mass had not been sent for histological section. The clinical implications are identical.
Chisin R, Gazit D, Ulmansky M, Laron A, Atlan H, Sela J
. 99mTc-MDP uptake and histological changes during rat bone marrow regeneration
[Internet]. Int J Rad Appl Instrum B 1988;15(4):469-76. Publisher's VersionAbstract
An established experimental model of tibial bone regeneration in rats was used in order to try to provide further information on the binding site of 99mTc-MDP, which is still not clearly defined. Four groups of rats on which surgical tibial bone marrow evacuation was performed and two control groups (nonoperated animals and sham-operated animals) underwent bone scan during the different stages of marrow regeneration; they were killed immediately after, and histological examination carried out. The correlation between the scintigraphic and the histological findings suggests that 99mTc-MDP binds primarily to calcification sites in young bone trabecules.
Bimstein E, Soskolne WA, Lustmann J, Gazit D, Bab I
. Gingivitis in the human deciduous dentition. A correlative clinical and block surface light microscopic (BSLM) study
[Internet]. J Clin Periodontol 1988;15(9):575-80. Publisher's VersionAbstract
This study examined the relationship between clinical and histomorphometric parameters in the human deciduous dentition. Clinical parameters including plaque index, gingival swelling, gingival color, tooth mobility and degree of root resorption were determined prior to the extraction of teeth. The teeth were extracted with their surrounding gingiva in order to preserve the in situ relationship between the hard and soft tissues. Histomorphometric analysis was carried out on 55 sites, using block surface light microscopy (BSLM). Apical migration of the junctional epithelium was found at 53% (29) of the sites. The gingival sulcus was shallow (0.3 +/- 0.19 mm) and coronal to the cemento-enamel junction at 84% (46) of the sites. Junctional epithelium with retepegs was present at 89% (49) of the sites, whilst an inflammatory cell infiltrate (ICI) was present at all sites examined. The ICI was located opposite to the junctional epithelium and cementum at 80% (44) of the sites. The extent of ICI correlated positively with the patients' age and was significantly increased when clinical evidence of gingival swelling or redness was present.
Bab I, Passi-Even L, Gazit D, Sekeles E, Ashton BA, Peylan-Ramu N, Ziv I, Ulmansky M
. Osteogenesis in in vivo diffusion chamber cultures of human marrow cells
[Internet]. Bone Miner 1988;4(4):373-86. Publisher's VersionAbstract
The osteogenic diffusion chamber culture of rodent marrow cells is a well established system. In the present study, marrow cells from children and adult human donors were incubated in diffusion chambers implanted intraperitoneally in athymic mice. After 4 or 8 weeks, the chamber content was examined by light and electron microscopy. Child-cell cultures showed osteogenic tissue consisting of a mineralizing fibrous component and cartilage. Ultrastructurally, the fibrous tissue was similar to osteoid and exhibited osteoblast-like cells and mineralizing nodules. Mineral aggregates were also found in the cartilage. These features in child-cell chambers were similar to those found in control chambers of rabbit marrow cells. Adult-cell chambers showed only unmineralized fibrous tissue. These results render previous findings in animal-cell diffusion chamber systems relevant to the understanding of bone formation in man. It is suggested that the difference between child- and adult-cell chambers reflects an age-related decline in the number of marrow osteoprogenitor cells or their potential to undergo terminal osteogenic differentiation.
Bab I, Gazit D, Muhlrad A, Shteyer A
. Regenerating bone marrow produces a potent growth-promoting activity to osteogenic cells
[Internet]. Endocrinology 1988;123(1):345-52. Publisher's VersionAbstract
It is well documented that injury to bone marrow is followed by an osteogenic phase that precedes the complete tissue regeneration. We have recently shown that postablation healing of bone marrow in rat tibiae is associated with a systemic increase in osteogenesis. It was hypothesized that a growth factor(s) with an effect on osteogenic cells is produced in the healing limb, is transferred to the blood circulation, and enhances osteogenesis systemically. To test growth factor production, healing bone marrow-conditioned medium was prepared with tissue separated from rat tibias during the osteogenic phase and assayed for enhancement of mitogenic activity in culture of osteogenic rat osteosarcoma cells (ROS 17/2). Partial purification of healing bone marrow-conditioned medium-derived growth factor(s) consisted of gel filtration on Sephadex G-25, boiling, chromatography on heparin-Sepharose, and gel filtration on Sephadex G-75. Mitogenic activity eluted in the void volume of the Sephadex G-25 column (mol wt greater than 5,000). Potent activity resolved from heparin-Sepharose with PBS, and on filtration by Sephadex G-75 this activity recovered in 3 peaks with mol wt estimates of 35,000, 19,000, and less than 10,000. The partially purified factor also showed considerable stimulatory effect on DNA synthesis in osteoblastic fetal rat calvarial cells and on in vitro elongation of fetal long bone; it had only a small effect on nonosteoblastic ROS and fetal rat calvarial cells. These data indicate that healing bone marrow produces growth factor activity with a preferential effect on osteogenic cells. It is suggested that local growth factors have a role as mediators in the sequence of events whereby bone marrow expresses its osteogenic potential. During postablation healing of bone marrow these factors may also function as systemic promoters to osteogenic cells.