Evaluation of the peri-implant membrane induced around ceramic dental implants in dogs: a transmission electron microscopic study.

A description of the supporting tissues of single-crystal sapphire implants which had functioned for twelve months is reported. The tissue was recovered at autopsy. The peri-implant membrane was formed by the action of mastication forces on the implants and consisted of three non-mineralized connective tissue layers. Layer I was composed of collagen fibers. These fibers were oriented parallel to the implant surface. Layer II lacked collagen fibers. This layer was composed of connective tissue materials. Layer III was covered by osteoclasts or osteoblasts. This layer was composed of collagen fibers which radiated to the bone surface. The collagen fiber bundles did not run from the implant fibers to the bone fibers. This peri-implant membrane formed only a hammock-like supporting mechanism. These findings suggest that the implant had been encapsulated by the peri-implant membrane, which failed to distribute masticulation stress to the peripheral tissues. One year after implantation of single-crystal implants, the tissue-implants interface was observed. Non-mineralized connective tissue layers (a "peri-implant membrane") existed at all implant interfaces. The origin of this structure and the role of a peri-implant membrane are discussed.

Cytocidal effects of hematoporphyrin derivative and argon dye laser on human gynecologic tumor cells in vitro.

Antitumor effects of hematoporphyrin derivative (HpD) plus argon dye laser were examined using various human gynecologic tumor cells in vitro. Irradiation alone with argon dye laser showed no effect on the DNA synthesis of cells. Treatment of the cells with HpD inhibited the DNA synthesis depending on the concentration and the exposure time. Photoradiation by argon dye laser following treatment of the cells with HpD 40 micrograms/ml for 2 h killed more than 80% of cells when the cells were irradiated for more than 3 min. Prominent degenerative changes of the cytoplasm and the nucleus appeared within 1 h after photoradiation. These changes were confirmed by morphology and DNA histogram. There were no differences of sensitivity to photoradiation among the three histologically different kinds of cells lines used.

[Anticancer effect of VP16-213 (etoposide) on three choriocarcinoma cell lines].

A new anticancer drug, VP16-213 was studied in vitro to determine its effect upon 3H-thymidine uptake and the survival rate of choriocarcinoma cells in comparison with the effect of MTX and Act-D. Three human choriocarcinoma cell lines, BeWo, HCCM-5 and SCH were used. The results were as follows; Serum VP16-213 levels were 10.3 +/- 1.19 micrograms/ml and 1.35 +/- 0.38 micrograms/ml at one hour and 12 hours after the administration of 100mg of VP16-213, respectively. In those three cell lines, VP16-213 suppressed cellular 3H-thymidine uptake by 70% as compared with the control. On the sixth day after exposure to VP16-213, the survival rate of choriocarcinoma cells was less than 10% in each of the three cell lines. One of the most prominent pharmacodynamic characteristics of VP16-213 was a rapid influx and efflux mechanism as seen in MTX. From the above, the anticancer effect of VP16-213 upon those three cell lines was supposed to be equal to or more than those of MTX and Act-D.

[Synergistic effect of amphotericin B and actinomycin-D against two human choriocarcinoma cell lines].

The sensitivity to actinomycin-D (Act-D) and the changes in survival rate of two human choriocarcinoma cell lines (BeWo and SCH) were studied in vitro and the following results were obtained. BeWo was shown to be more sensitive to Act-D than SCH, when the survival rate was compared in the two cell lines. 3H X Act-D uptake was 39 pmol/10(6) cells in BeWo and 12 pmol/10(6) cells in SCH after a two hours treatment. Those results suggested that the sensitivity to Act-D of choriocarcinoma cells was positively correlated with the intracellular Act-D concentration. The intracellular Act-D concentration was increased depending upon the concentrations of amphotericin B (AMB). After a two hours treatment with Act-D and AMB, the intracellular Act-D concentrations were twice in BeWo, and 2.3 times in SCH comparing with those treated with Act-D alone. The synergistic effects of Act-D and AMB on the survival rate were 1,000 times in BeWo and 100 times in SCH compared with those treated with Act-D alone. From the above, combination therapy with Act-D and AMB was supposed to be one of the trial methods in the treatment of drug resistant choriocarcinoma.

[In vitro sensitivity test of anti-neoplastic agents and their enhancement by biscoclaurine alkaloid].

UNLABELLED: We tried an in vitro sensitivity test for the purpose of examining the effect of anti-neoplastic agents and their enhancement by Biscolaurine Alkaloid (Cepharanthin). Methods, HeLa cells were synchronized by excess of thymidine and hydroxyurea, and resuspended in Eagle's MEM with 10% FCS. The cells were mixed with Mitomycin C or Bleomycin and added to the wells of a microtiter plate. When required, Cepharanthin (the effect of this drug is considered to change the plasma membrane liquidity) was added to the medium, and then cultured for 24 hours in a CO2 incubator. After culture, each well received 3H-thymidine, and was incubated for 8 hours. The cells were harvested for the assay of 3H-thymidine. RESULTS: MMC or BLM suppressed the uptake of 3H-thymidine in relation to its concentration. MMC or BLM with various concentrations of Cepharanthin showed strong suppression compared with the same concentrations of MMC or BLM alone. From the above results, this experimental method is regarded as an useful model for selecting sensitive anti-neoplastic agents. In addition, Cepharanthin showed enhancing effects on anti-neoplastic agents.

Peplomycin sulfate and pulmonary fibrosis: hydroxyproline, uronic acid, proline hydroxylase and glucosamine 6-phosphate synthetase in lungs of hamsters treated with peplomycin.

Effect of peplomycin sulfate (PLM) on pulmonary fibrosis was examined. Hydroxyproline, uronic acid, proline hydroxylase (EC 1.14.11.2) and glucosamine 6-phosphate synthetase (EC 2.6.1.16) in lungs of hamsters treated with PLM were studied and compared with those of hamsters treated with bleomycin (BLM). PLM, when administered intraperitoneally, one injection daily for 10 consecutive days, at either a high- (5 mg/kg) or low- (2.8 mg/kg) dosage-level, caused no significant increase of lung hydroxyproline and uronic acid as compared with controls. BLM on the other hand effected a significant increase in lung hydroxyproline on the high-dosage level (5 mg/kg) but not on the low-dosage level (2.8 mg/kg). In contrast, when administering PLM intratracheally, the concentrations of hydroxyproline in lungs increased 20% over the control levels. A transient increase of proline hydroxylase and glucosamine 6-phosphate synthetase also occurred shortly after the instillation. These increases were also observed in the corresponding groups treated with BLM, which confirmed the previous observations by other investigators. However, the magnitude of the increase was relatively lower in those values of PLM as compared with those of BLM. These data suggested that (1) PLM, when administered with multiple dosages intraperitoneally, showed no significant effect on the elevation of lung hydroxyproline; (2) PLM, when administered with a dose intratracheally, induced pulmonary fibrosis similar to that caused by BLM. However, the hydroxyproline accumulation in lungs of PLM-treated hamsters was less than in those of the BLM-treated; (3) The fibrotic effect on the lungs caused by either PLM or BLM was probably attributed to acceleration of the syntheses of collagen and acidic glycosaminoglycans.

Distribution of intracytoplasmic acidophilic granule-containing neurons in the human brain.

Using four autopsied brains, we studied the anatomic locations of the intracytoplasmic acidophilic granule (IAG)-containing neurons. These neurons occurred in the hypothalamus, zona incerta, insular cortex, and the other 23 nuclei. However, IAGs were not observed in neurons of the Ammon's horn, thalamus, dentate nucleus, or in Purkinje cells of the cerebellum. The distribution of IAG-containing neurons does not exactly correspond to that of the neuromelanin- or monoamine-forming neurons. There is, however, a striking parallelism between the IAG-containing neurons map and the Lewy bodies map. It is suggested by the superimposition of both maps that IAG-containing neurons may have a certain metabolic relation to the formation of Lewy bodies.