pS2 expression induced by American ginseng in MCF-7 breast cancer cells

Background: Alternative medicines are frequently used by patients with breast cancer for general health benefits. American ginseng, an herbal remedy, purportedly alleviates treatment-induced postmenopausal symptoms. Methods: Estrogenic potential of American ginseng root extract to induce the expression of pS2, an estrogen-regulated gene, was evaluated in breast cancer cell lines MCF-7, T-47D, and BT-20 by Northern and Western blot analysis. Competitive studies were performed with ginseng in combination with tamoxifen. Cell proliferation assays were performed using the tetrazolium dye procedure and direct cell count. Results: Ginseng and estradiol induce the expression of pS2 RNA and protein in MCF-7 cells, whereas tamoxifen suppresses expression. Neither ginseng nor estradiol induced increased pS2 expression in T-47D or BT-20 cell lines. Although estradiol exhibited a proliferative effect and tamoxifen had an inhibitory effect, ginseng demonstrated no significant effect on cell proliferation. Conclusions: The results of this study suggest that ginseng may exhibit estrogenlike effects on estrogen receptor-positive breast cancer cells by inducing pS2 expression and that the effect of ginseng may be mediated in part through the estrogen receptor. Because ginseng does not exhibit a proliferative effect, it may play a protective role against breast cancer rather than serve as a mitogen.Presented at the 48th Annual Cancer Symposium of The Society of Surgical Oncology, Boston, Massachusetts, March 23–26, 1995.     

Collagen arrangements in ureter

Summary The collagen fibres of rabbit and human ureter were exposed by digestion with trypsin and hyaluronidase. The fibre structure was examined using an SEM and examples of the inner and outer fibre structures are shown together with the effects of different types of mechanical strain. An interesting difference between the arrangements of the inner fibres of human and rabbit was seen where the human ureter had a cross-ply structure while in the rabbit it was helical.     

Effects of rubidium on responses to potassium channel openers in rat isolated aorta.

1. In a physiological salt solution (PSS) in which potassium (K) was replaced by rubidium (Rb), segments of rat aorta precontracted with 20 mM RbCl were fully relaxed by K-channel openers with an order of potency levcromakalim > cromakalim > aprikalim > RP 49356. These relaxations were inhibited by glibenclamide. 2. Segments of rat aorta bathed in normal PSS and precontracted with 20 mM KCl were also relaxed by these K-channel openers with an order of potency levcromakalim > cromakalim > aprikalim > RP 49356. These relaxations were glibenclamide-sensitive. However, the absolute potencies of the K-channel openers were approximately four times greater in normal PSS than in RbPSS. 3. In RbPSS, minoxidil sulphate relaxed segments of aorta precontracted with 20 mM RbCl by approximately 20% whereas in normal PSS it fully relaxed those contracted with 20 mM KCl. 4. In RbPSS, levcromakalim-induced relaxation of aortic segments precontracted with 20 mM RbCl was initially well-maintained but then faded by approximately 60% of the initial relaxation to a new, stable level. Subsequent exposure to RP 49356 or to higher concentrations of levcromakalim was without further relaxant effect. Similar changes were observed when RP 49356 was the initial relaxant and tissues were exposed to either RP 49356 or levcromakalim. In normal PSS, levcromakalim- or RP 49356-induced relaxation of contractions produced by 20 mM KCl was well-maintained. 5. In RbPSS, minoxidil sulphate-induced relaxation of aortic segments precontracted with 20 mM RbCl was well-maintained. Subsequent exposure to either levcromakalim or to RP 49356 produced further tissue relaxation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Gastric Duplication Cyst: Electron Microscopic and Immunohistochemical Study

The lining of a gastric duplication cyst was examined ultrastructurally and immunohistochemically. The cyst lining displayed the range of differentiation seen in normal fundic mucosa.     

Reversible visual evoked potential abnormalities in vitamin E deficiency

A patient with cystic fibrosis and cirrhosis developed a progressive neurological syndrome associated with ataxia, proximal weakness, and ophthalmoplegia. Profound deficiencies of vitamins A, D, and E were present. Visual acuity and results of retinal funduscopy were normal. The pattern reversal visual evoked potential was initially abnormal (P100 latency, 136 and 130 ms from left and right eyes, respectively) but became normal (less than 3 standard deviations from mean control P100 latency) over a two-month period when vitamin E was administered. This case documents a potentially reversible visual evoked potential abnormality in a visually asymptomatic patient with vitamin E deficiency.