Hop bract polyphenols reduced three-day dental plaque regrowth.

Previous research has shown the inhibitory effects of hop bract polyphenols (HBP) on cariogenic streptococci in vitro, but their effects in humans have not been investigated. This double-blind, crossover clinical study tested the hypothesis that HBP delivered in a mouthrinse suppresses plaque regrowth in humans. Twenty-nine healthy male volunteers had all plaque removed, and refrained from all oral hygiene for 3 days, except for rinsing with a mouthrinse containing 0.1% HBP or a placebo. The results showed that the mean amount of plaque assessed by the Patient Hygiene Performance score after the volunteers used the HBP mouthrinse was significantly less than that after they used the placebo (p < 0.001). The number of mutans streptococci in the plaque samples after volunteers used the HBP mouthrinse was significantly lower than that after they used the placebo (p < 0.05). These findings suggested that HBP, delivered in a mouthrinse, successfully reduced dental plaque regrowth in humans.

[Analysis of inquiries about prescriptions at the pharmacy of Gifu Pharmaceutical University].

The Ministry of Health, Labour and Welfare explains the objectives of promotion of separation of the pharmacy and clinics as the elimination of duplicated prescription of similar drugs and drug interactions caused by treatment at several departments or hospitals, and sufficient guidance in the use of drugs by pharmacists. The Pharmacy of Gifu Pharmaceutical University has dispensed prescriptions by outside medical organizations as its routine activity. In this study, the contents of question inquiries handled in routine activities were compiled and analyzed, and their meaning was evaluated. The contents of question inquiries were accumulated using data cards. The data obtained during 2 and a half years (562 cases) were analyzed. The percentage of the number of inquiries relative to the number of prescriptions was highest at 1.86% during the first 3 months and was 1.05-1.71% per 3 months thereafter. The inquiries were most frequently about "the dosage/regimen" (153 cases), followed by "discrepancy between the contents of prescription and understanding of the patient" (88 cases) and "problems about insurance coverage" (80 cases). There were also 16 inquiries about "the possibility of contraindications and adverse reactions" and 15 inquiries about "duplicated prescription", which may have exerted serious effects on the patients. Eighty nine % of the inquiries have led to changes in the prescriptions, and about half of these cases were discovered by consultation with the patients or a review of the drug history. Proper and positive execution of these operations in routine pharmacy work is considered to lead to appropriate inquiries about problems with prescriptions and, thus, contribute to the proper use of drugs and prevention of malpractice.

Site-dependent effect of O-glycosylation on the conformation and biological activity of calcitonin.

We synthesized seven O-glycosylated calcitonin derivatives, each with a single GalNAc residue attached to either Ser or Thr, and studied their three-dimensional structure and biological activity to examine site-dependent effects of O-glycosylation. The CD spectra in an aqueous trifluoroethanol solution showed that the GalNAc attachment at Thr6 or Thr21 reduced the helical content of calcitonin, indicating that the O-glycosylated residue functions as a stronger helix breaker than the original amino acid residue. Only the GalNAc attachment at Ser2 or Thr21 retained the hypocalcemic activity of calcitonin. This result corresponded well to that of the calcitonin-receptor binding assay. The GalNAc attachment other than Ser2 or Thr21 perturbed the interaction with the receptor, resulting in the loss of the hypocalcemic activity. The biodistribution did not change much among the seven derivatives, but some site dependency could also be observed. Thus, we can conclude that the O-glycosylation affects both the conformation and biological activity in a site-dependent manner.

Effect of carbohydrate structure on biological activity of artificially N-glycosylated eel calcitonin.

To reveal the function of the carbohydrate portion of glycopeptides and glycoproteins, we chemo-enzymatically synthesized artificially N-glycosylated derivatives of eel calcitonin and studied their three-dimensional structure and biological activity. The CD and NMR spectra in trifluoroethanol-H(2)O solution showed that the glycosylation did not change the three-dimensional structure. All the derivatives retained the strong in vivo hypocalcemic activity of calcitonin. However, the relative activity was dependent on the structure of the attached carbohydrate. The single GlcNAc attachment best enhanced the activity, while larger carbohydrates decreased the activity. This relative activity order of compounds could be partly explained by their calcitonin-receptor binding affinity, though the affinity of the GlcNAc derivative did not exceed that of calcitonin. The enhanced hypocalcemic activity of the GlcNAc derivative was explained by its altered biodistribution. The GlcNAc attachment caused calcitonin to escape from the trap at the liver during the early circulation. Thus, the glycosylation was shown to modulate the biological activity of calcitonin depending on the carbohydrate structure without a change in the peptide backbone conformation.

Expression of perforin and Fas ligand mRNA in the liver of viral hepatitis.

Cytotoxic T lymphocytes (CTLs) play an important role in the pathogenesis of viral hepatitis. We studied the expression of mRNAs of perforin and Fas ligand (Fas-L) in biopsy specimens from chronic hepatitis B (CHB) (15 cases) and hepatitis C (CHC) patients (13 cases). Both perforin and Fas-L mRNAs were detected in all cases of both CHB and CHC. No messages were detected in the control livers from two cases of fatty liver, a case of Gilbert's syndrome, and a case of Dubin-Johnson syndrome. Semiquantitative analysis revealed a positive correlation between the intensity of perforin and Fas-L mRNAs in both CHB and CHC. In CHB, the intensity of both perforin and Fas-L mRNAs showed a positive correlation with the histological activity and serum alanine aminotransferase level, while the correlation was not apparent in CHC. These results suggest that both perforin and Fas/Fas-L systems are involved in the pathogenesis of liver cell injury of CHB and CHC.

Mithramycin represses MDR1 gene expression in vitro, modulating multidrug resistance.

The effect of an aureolic acid, mithramycin (MTM) on multidrug resistance (MDR) was investigated. At a concentration of 0.02--0.1 mg/ml (about 20--90 microM), MTM repressed MDR1 gene transcription of SBC-3/ADM, a MDR-phenotype subline derived from human small cell lung tumor. Under the same conditions, another aureolic acid, chromomycin A3, showed potent cytotoxicity. FACS analysis revealed that 5 microm MTM depleted the P-glycoprotein (Pgp) and lowered the efflux activity of SBC-3/ADM cells. Furthermore, MTM sensitized the cells against adriamycin. These results suggest that MTM would be a useful modulator of MDR induced by Pgp.

Two novel C-glycosides of aureolic acid repress transcription of the MDR1 gene.

In the search for compounds which repress MDR1 gene expression, two novel aryl C-glycosides were isolated from a broth of Streptomyces sp. They had the characteristic structure of a dideoxy-carbohydrate (oliose or olivose) linked directly to chromomycinone, an aglycone of aureolic acids. Further investigation revealed that they were artifacts yielded from an aureolic acid, mithramycin. Acid and methanol were necessary to yield the C-glycosides. This reaction would contribute to the design of useful aryl C-glycosides.

Fcgamma receptor expression on hepatic macrophages and histological activity of chronic hepatitis.

AIMS/BACKGROUND: Activated liver macrophages in chronic hepatitis express a high affinity receptor for IgG named FcgammaRI. This study was performed to find the difference in FcgammaRI expression between chronic hepatitis B (CHB) and C (CHC) with reference to histological activity. METHODS: Consecutive patients with CHB (20 cases) and CHC (25 cases) were enrolled in the study. Inflammatory activity was evaluated using the modified histological activity index (HAI). FcgammaRI-positive macrophages were quantitatively measured by computer assisted morphometry. RESULTS: Total HAI score was significantly higher in CHB than in CHC. Confluent necrosis was observed in significantly higher frequency in CHB at Stages 3 5 than in CHC. The percentage area of FcgammaRI-positive macrophages was significantly higher in CHB than in CHC. In CHB, the percentage area of FcgammaRI-positive macrophages correlated with total HAI (<0.01) as well as the degree of confluent necrosis (<0.01), interface hepatitis (<0.05) and portal inflammation (<0.05). FcgammaRI-positive macrophages accumulated mainly at the site of confluent necrosis. In CHC, no correlation was observed between activated macrophages and any histological categories. CONCLUSION: These results suggest that FcgammaRI-positive macrophages are associated with confluent necrosis in CHB, which is more common in CHB patients than in CHC.

Immunohistochemical study on phenotypical changes of hepatocytes in liver disease with reference to extracellular matrix composition.

AIMS/BACKGROUND: Extracellular matrix (ECM) may affect the function and phenotype of hepatocytes. Phenotypic changes of hepatocytes in diseased liver were investigated with reference to ECM composition. METHODS: Immunohistochemistry was performed on biopsied liver samples from chronic viral hepatitis (CVH), primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC) and normal patients, using monoclonal antibodies for laminin, type IV collagen, cytokeratin 19 (CK19) and epithelial glycoprotein (EGP), a protein homologous to nidogen. RESULTS: In normal controls, both EGP and CK 19 were expressed exclusively on biliary epithelia. Laminin and type IV collagen were expressed around portal bile ducts and blood vessels. Although type IV collagen was expressed in Disse's space, laminin was scarcely expressed. In all pathological livers, both EGP and CK 19 were expressed in proliferated bile ductules. In CVH with piecemeal necrosis, EGP was expressed on periportal hepatocytes, while CK19 expression was limited to a few hepatocytes. Laminin was expressed in Disse's space of periportal sinusoids, where EGP was expressed on hepatocytes. EGP expression on hepatocytes and laminin deposition in Disse's space were rare in PBC and PSC liver. CONCLUSION: These results suggest that hepatocytes transform into a phenotype similar to biliary epithelia and, laminin deposition in Disse's space (capillarization of sinusoids) may play a role in this phenotypic change.

Cytokine profile in the liver of primary biliary cirrhosis.

We characterized the cytokine profile in the liver of patients with primary biliary cirrhosis (PBC). Total RNA was extracted from the biopsy specimens of 9 patients with early-stage PBC, 10 with chronic hepatitis C (CHC), and 4 normal controls. cDNA was prepared and amplified with a polymerase chain reaction using primers for interferon (IFN)-gamma and interleukin (IL)-2, -4, -5, -6, -10, -12 (p40), and -15. Cytokines such as IFN-gamma and IL-5, -6, -10, -12, and -15 were expressed in most cases of PBC. Expression rates of IL-5 and IL-6 were higher than in CHC and controls. The higher expression rate of IL-5 in PBC was associated with eosinophil infiltration. IL-2 and IL-4 were rarely detected. Semiquantitative analysis revealed that the expression of IFN-gamma and IL-10 was reversed in PBC and CHC: high IFN-gamma and low IL-10 in PBC and high IL-10 and low IFN-gamma in CHC. These results suggest that cytokine expression is skewed in PBC and both Th1 and Th2 cytokines may play a role in the pathogenesis.

5-Hydroxy-4-oxo-L-norvaline depletes intracellular glutathione: a new modulator of drug resistance.

To search for compounds that reverse the drug resistance induced by glutathione (GSH), an original screening system to detect intracellular GSH depleters was established. Among 8843 microbes derived from the soil samples tested, the extracts of two Streptomyces species named KS6701 and KS8846, lowered the intracellular GSH level of Saccharomyces cerevisiae 5 x 47. From both the microbes, 5-hydroxy-4-oxo-L-norvaline (HON) was isolated as the active compound. At a concentration of 50-100 micrograms/ml, HON also decreased the GSH/protein level of the human ovarian tumor cell line, 2008/C13*5.25 and reversed its resistance to cisplatin. We also investigated the mechanism of the depletion. HON had little effect on gamma-glutamylcysteine synthetase (gamma-GCS) or glutathione synthetase, but HON decreased the quantity of thiol substances when it was spontaneously reacted with them. This suggested that the GSH depletion by HON occurred through a mechanism different from that of buthionine sulfoximine, a selective gamma-GCS inhibitor.

Inhibition by hop bract polyphenols of cellular adherence and water-insoluble glucan synthesis of mutans streptococci.

The inhibitory effect of hop bract polyphenols (HBP) on cariogenic streptococci was investigated. It was found that the high molecular weight polyphenol (estimated about 36,000-40,000) inhibited the cellular adherence of Streptococcus mutans MT8148 (serotype C) and Streptococcus sobrinus ATCC 33478 (serotype g) at much small concentrations than the polyphenols extracted from oolong tea or green tea leaves. Furthermore, HBP also inhibited the action of glucosyltransferase, which was involved in the water-insoluble glucan synthesis, but did not suppress the growth and the acid production of the bacteria. These results suggest that HBP would be a candidate to act against dental caries caused by Mutans Streptococci.

Antioxidative activity of hop bitter acids and their analogues.

Hop bitter acids, humulones (1) and lupulones (2), were shown to have potent DPPH radical scavenging activity (RSA) and lipid peroxidation inhibitory activity (LIA). Furthermore, 5-acetyl lupulones (3) and 4-methyl lupulones (4) had more potent LIA than native lupulones but no RSA. This result indicates that the beta, beta'-triketone moiety of the lupulones has LIA.