Mechanical force augments the anti-osteoclastogenic potential of human gingival fibroblasts in vitro.

BACKGROUND AND OBJECTIVE: The cellular response of human gingival fibroblasts to a mechanical force is considered to be primarily anti-osteoclastic because they produce relatively high levels of osteoprotegerin. However, there is little information available on the effects of compression force on the production of osteoprotegerin and osteoclastic differentiation by these cells. In this study, we examined how mechanical force affects the nature of human gingival fibroblasts to produce osteoprotegerin and inhibit osteoclastogenesis. MATERIAL AND METHODS: Human gingival fibroblasts were exposed to mechanical force by centrifugation for 90 min at a magnitude of approximately 50 g/cm(2). The levels of osteoprotegerin, receptor activator of nuclear factor-kappaB ligand (RANKL), interleukin-1beta and tumor necrosis factor-alpha were measured at various time-points after applying the force. The effect of the centrifugal force on the formation of osteoclast-like cells was also determined using a co-culture system of human gingival fibroblasts and bone marrow cells. RESULTS: Centrifugal force stimulated the expression of osteoprotegerin, RANKL, interleukin-1beta and tumor necrosis factor-alpha by the cells, and produced a relatively high osteoprotegerin to RANKL ratio at the protein level. Both interleukin-1beta and tumor necrosis factor-alpha accelerated the force-induced production of osteoprotegerin, which was inhibited significantly by the addition of anti-(interleukin-1beta) immunoglobulin Ig isotype; IgG (rabbit polyclonal). However, the addition of anti-(tumor necrosis factor-alpha) immunoglobulin Ig isotype; IgG1 (mouse monoclonal) had no effect. Centrifugal force also had an inhibitory effect on osteoclast formation. CONCLUSION: Application of centrifugal force to human gingival fibroblasts accelerates osteoprotegerin production by these cells, which stimulates the potential of human gingival fibroblasts to suppress osteoclastogenesis. Overall, human gingival fibroblasts might have natural defensive mechanisms to inhibit bone resorption induced by a mechanical stress.

Stimulating effects on mouse splenocytes of glycoproteins from the herbal medicine Atractylodes macrocephala Koidz.

A traditional herbal medicine, Atractylodes macrocephala Koidz. (AMK), has long been used as a digestive and tonic. Recent investigations have suggested its potential ability in stimulating immune responses, although a scientific basis for this activity has not yet been elucidated. Based on previous results showing that the activity might be due to proteins, we purified protein samples from an original sample preparation of AMK and examined the stimulating ability of the protein samples on mouse splenocytes. The sample treatment markedly stimulated lymphocyte proliferation, antibody production, and cytokine secretion in mouse splenocytes. In particular, the samples showed the ability to induce the preferential stimulation of Th1 type, rather than Th2 type T lymphocytes. Stimulating activity of the samples was associated closely with glycoprotein(s) with molecular weights of around 30 kDa, especially with carbohydrate moiety rather than with protein residues of the glycoprotein(s). Our findings suggest that the glycoprotein(s) might play critical roles in modulating immune-response induction, and could potentially be used as medicinal and pharmacological agents.

Plant-originated glycoprotein, G-120, inhibits the growth of MCF-7 cells and induces their apoptosis.

We characterized the biological function of G-120, glycoprotein isolated from the ethanol extract of the herb, Ulmus davidiana Nakai (UDN). G-120 has anti-tumor activity and significantly inhibited proliferation of MCF-7 cells, as measured by the thymidine uptake assay. In addition, MTT and trypan blue exclusion experiments showed that the G-120-mediated inhibition of DNA synthesis may be due to a cytostatic, rather than a cytotoxic effect. Further studies of DNA analysis and propidium iodide staining revealed that G-120 induces apoptosis in MCF-7 cells. Interestingly, G-120 (100 microg/ml) completely suppressed the binding of NF-kappaB to DNA and increased the cytosolic level of IkappaBalpha which prevented nuclear translocation of NF-kappaB. In addition, G-120 increased the expression of c-Jun, Fra-1, and Fra-2, but did not affect the expression of c-Fos. Collectively, it is believed that G-120 exerts an important role in the induction of apoptosis, suppression of NF-kappaB activation, and induction of c-Jun/Fra-1 or c-Jun/Fra-2 dimerization in MCF-7 cells. Consequently, G-120 could be considered as an anti-cancer agent, although further detailed experiments should be performed.

Ripe fruit of Solanum nigrum L. inhibits cell growth and induces apoptosis in MCF-7 cells.

Solanum nigrum L. (SNL) has been traditionally used as a herbal plant, whose fruit is believed to have anti-tumor properties, although the mechanism for the activity remains to be elucidated. In this study, we prepared an ethanol extract from ripe fruits of SNL and investigated the mechanism involved in its growth-inhibitory effect on MCF-7 human breast cancer cells. Results from proliferation assay using tritium uptake showed that the proliferative capacity of MCF-7 cells was strongly suppressed in the presence of SNL ethanol extract. This was further confirmed through MTT assay and trypan blue exclusion experiments, which showed a very close correlation between the SNL extract concentration and the surviving cell numbers. The SNL extract-mediated suppression of cell growth was verified to be apoptotic, based on the appearance of DNA laddering, increase in DNA fragmentation, and low fluorescence intensity in nuclei after propidium iodide staining of the cells. Furthermore, the SNL extract was revealed to be a potential scavenger of hydroxyl radicals and DPPH radicals rather than superoxide anions. Collectively, our findings suggest that SNL fruit extract could be used as an anti-oxidant and cancer chemo-preventive material.

A simplified method of assessing hemodynamics in technetium-99m sulfur colloid liver imaging.

A total of 204 Tc-99m sulfur colloid hemodynamic studies of the liver taken at 5-second intervals were evaluated. The time when the gradually increasing activity in the liver becomes equal to the reducing activity in the heart pool is defined as the relative half clearance time (RHCT) of cardiac activity to the liver. The RHCT was measured in each scan and was correlated with clinical information, liver function tests, and static scan findings. Normal RHCT was established to be in the range of 40 +/- 20 seconds. This study indicates that the RHCT truly reflects the functional status of the hepatic blood flow as well as the phagocytic activity of the Kupffer cells of the liver when cardiac function is normal. A prolonged RHCT may indicate the presence of a parenchymal disease of the liver or cardiac failure with hepatic congestion, or both. The longer the RHCT, the more severe the pathologic condition of the liver, provided that cardiac function is normal.

Ureteral diverticulosis in a case of dermatomyositis.

We present the third case of ureteral diverticulosis discovered by excretory urography alone and the twenty-sixth case reported in the world literature. Unlike previously reported cases our patient had dermatomyositis and is urologically asymptomatic.