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Chemically modified compounds of glycyrrhizin have been synthesized and evaluated for their inhibitory effect on the replication of human immunodeficiency virus type 1 (HIV-1) and herpes simplex virus type 1 (HSV-1). Among them, the 11-deoxo compound having a heteroannular diene structure at the C and D rings proved as active against HIV-1 as glycyrrhizin in MT-4 and MOLT-4 cells. It completely inhibited HIV-1-induced cytopathogenicity in both cell lines at a concentration of 0.16 mM. The compound was also effective against HSV-1 with a 50% inhibitory concentration of 0.5 mM [corrected].

The anode properties of pristine MgH2 and MgH2 catalyzed with Nb2O5 have been investigated for an all solid-state lithium-ion battery. The catalytic effect stabilizes the plateau voltage as a result of kinetic improvement of the hydrogen transfer from the Mg phase to the Li phase.

Low density vascular smooth muscle (VSM) cell cultures maintained on extracelIular-matrix (ECM)-coated dishes and plated in the presence of either plasma or serum will proliferate actively when serum-containing medium is replaced by a synthetic medium supplemented with three factors: high density lipoprotein (HDL, 250,ug protein/ml) ; insulin (2 .5 pg/ ml) or somatomedin C (10 ng/ml) ; and fibroblast growth factor (FGF, 100 ng/ml) or epidermal growth factor (EGF, 50 ng/ml) . The omission of any of these three factors from the synthetic medium results in a lower growth rate of the cultures, as well as in a lower final cell density once cultures reach confluence . When cells are plated in the total absence of serum, transferrin (10ILg/ml) is also required to induce optimal cell growth .The effects of the substrate and medium supplements on the life span of VSM cultures have also been analyzed . Cultures maintained on plastic and exposed to medium supplemented with 5% bovine serum underwent 15 generations . However, when maintained on ECM-coated dishes the serum-fed cultures had a life span of at least 88 generations. Likewise, when cultures were maintained in a synthetic medium supplemented with HDL and either FGF or EGF, an effect on the tissue culture life span by the substrate was observed . Cultures maintained on plastic underwent 24 generations, whereas those maintained on ECM-coated dishes could be passaged repeatedly for 58 generations . These experiments demonstrate the influence of the ECM-substrate not only in promoting cell growth but also in increasing the longevity of the cultures .Previous studies have shown that bovine vascular smooth muscle (VSM) cells maintained on dishes coated with extracellular matrix (ECM) proliferate equally well when exposed to either plasma or serum (13). Among the plasma components that could affect the proliferation of VSM cells are the high (HDL) and low density lipoproteins (LDL), both of which have been reported to be mitogenic for that cell type when cultures are exposed to lipoprotein-deficient serum (LPDS ; 3, 5, 28) or to serum from abetalipoproteinemic subjects (24). Insulin, epidermal growth factor (EGF), and fibroblast growth factor (FGF) might also affect VSM cell proliferation, inasmuch as these agents have been shown to be mitogenic for a wide variety of cell types maintained under serum-free conditions (1, 2, 31) as well as for VSM cell cultures exposed to plasma (16,18) . Transferrin could also be required (1, 2, 31) to make iron available to the cells.To define which of these factors are important for proliferation of VSM cells, we have studied the proliferative response of low density VSM cell cultures that were plated in the presence of serum or plasma, and then exposed to a synthetic medium supplemented with LDL, HDL, insulin, and FGF, and have compared the effects of the substrate (either ECM or plastic) on the proliferative response to these agents. Our results indicate that VSM cells maintained on ECM-coated dishes proliferate actively when e...

Glycyrrhetinic acid (Ia) and eighteen related derivatives were examined for antiulcer activity using stress-induced gastric lesions (restraint plus water immersion at 25 degrees C) in mice and rats as screening tests. Among the compounds tested, dihemiphthalate derivatives of 18 alpha- or 18 beta-olean-12-ene-3 beta,30-diol (IV, IIId), 18 beta-olean-9(11)12-diene-3 beta,30-diol (VIc), and olean-11,13(18)-diene-3 beta,30-diol (VIIc) showed potent inhibition of gastric lesion formation at a dose of 12 or 25 mg/kg (p.o.); carbenoxolone sodium (Ib) significantly suppressed the lesion formation at a dose of 500 mg/kg (p.o.). Further evaluation of the antiulcer activity was carried out mainly for compound IIId. Compound IIId (p.o.) prevented the formation of indomethacin-induced or 0.6 N HCl-induced gastric lesions; the latter antiulcer effect was noted even in the combined treatment with indomethacin, suggesting that the effect occurs independently of endogenous prostaglandins. In contrast, compound IIId had no preventive effect against Shay rat ulcer when intragastrically (i.g.) administered; further, no antisecretory effect was seen by i.g. application in pylorus-ligated rats. Administration of compound IIId for 2 weeks accelerated the healing rate of acetic acid-induced gastric ulcer in rats. No significant change in urine excretion was observed after its consecutive administration for 3 d. These results suggest that dihemiphthalate derivatives (IIId, IV, VIc, VIIc) may produce a strong antiulcer activity, probably by strengthening some gastric mucosal defensive mechanism.