Biomedical subjects
Publications and source records attributed to Kenta Suzuki.
We achieved the first asymmetric total syntheses of novel Aspidosperma indole alkaloids, (-)-subincanadines A and B, which involve an intramolecular diastereoselective Pictet-Spengler cyclization and an intramolecular Nozaki-Hiyama-Kishi reaction as key steps in the total syntheses.
Enantiomorphous crystals composed of achiral hippuric acid, i.e., naturally occurring N-benzoylglycine, have been used successfully as chiral inducers in enantioselective synthesis in combination with asymmetric autocatalysis to afford the product with extremely high enantiomeric excess.
An enantiomerically enriched pyrimidyl alkanol with either S or R configurations was obtained stochastically from the reaction between pyrimidine-5-carbaldehyde and diisopropylzinc in the presence of achiral silica gel in conjunction with asymmetric autocatalysis with amplification of chirality.
The spreading of submonolayer liquid polymer films on a solid surface that consist of molecules with different mobilities was investigated. The molecular conformations of the adsorbed and free molecules were estimated from the dispersive surface energy measurement and the relationship between the diffusion coefficient of the free molecules and the coverage of the adsorbed molecules were obtained from the spreading profile measurement. A free mobile molecule lies flat on the solid surface and an adsorbed molecule lies less flat than a mobile one. The relation between the diffusion coefficient and the coverage can be explained by the percolation model at a small coverage and it can be explained by the reptation model at a large coverage.
Clinical background and incidence of hepatocellular carcinoma (HCC) of patients with chronic hepatitis C who obtained biochemical remission without eradication of virus (biochemical response) after interferon (IFN) treatment was retrospectively analyzed for 755 patients. Annual incidence of HCC was significantly lower in the patients with biochemical response and sustained response than that of the patients that did not show these responses. Logistic regression analysis showed that only the normalization of alanine aminotransferase (ALT) value at the end of IFN treatment was a significant factor for biochemical response. Annual incidence of HCC was significantly lower in the patients who obtained normalization of ALT values at the end of treatment than those who did not. Patients who were younger, who had a lower level of activity and fibrosis indices in histology, higher platelet count, and who were given more higher total dose of IFN were more likely to attain normalization of ALT levels at the end of treatment, and this was related to biochemical response. Low incidence of HCC in patients who obtained normalization of ALT values at the end of treatment was likely because they were in the earlier stage of chronic hepatitis. Active treatment of chronic hepatitis C with interferon in the early phase of the disease may bring about a biochemical response in some patients, even if sustained virological response is not obtained.
A 40-year-old woman with a history of fever and arthralgia since age 17 had received long-term prednisolone (PSL) therapy. She was diagnosed with Takayasu's arteritis in 1980 and given PSL. The symptoms were well controlled until she developed itching in 1998. Laboratory tests showed elevated levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma-glutamyltranspeptidase, total cholesterol, and immunoglobulin M (IgM). She tested positive for anti-mitochondria antibody and for both IgG and IgM anti-pyruvate dehydrogenases. Liver biopsy findings were typical of primary biliary cirrhosis (PBC). Our patient's clinical course suggested that an adequate amount of PSL to control Takayasu's arteritis does not necessarily prevent the development of PBC.
BACKGROUND/AIMS: The incidence of hepatocellular carcinoma among patients who have seroconverted to anti-hepatitis B surface antigen (anti-HBs) remains controversial. METHODOLOGY: We report four patients with chronic hepatitis B virus (HBV) infection who had cleared HBsAg and had developed anti-HBs at a later time, but who developed hepatocellular carcinoma (HCC) eventually. RESULTS: The common clinicopathological characteristics of the four patients were: An established diagnosis of precirrhosis or liver cirrhosis more than a decade previously, a long-standing normalization or stabilization at a low level of ALT values due to undetectable HBV DNA by the Amplicore Monitor assay, and a marked reduction of the fibrosis level in the non-tumorous liver obtained at HCC surgery or autopsy compared to the previous histology more than a decade previously. There was no fibrosis in the needle biopsy specimen from one patient. CONCLUSIONS: Our findings suggest that HCC due to HBV can occur in the serologically-cured stage if progression to pre-cirrhosis or cirrhosis already has occurred, where the fibrosis level has improved considerably because of the long-term absence of active HBV viremia and inflammation. Active medical intervention to prevent liver cirrhosis for chronic hepatitis B may have an important role in the inhibition of HCC in patients with chronic hepatitis B.
BACKGROUND/AIMS: The emergence of YMDD mutants in patients who are treated with lamivudine may determine the clinical prognosis. However, currently there are no clinical or virological factors that predict specifically the emergence of the mutants. METHODOLOGY: To define these factors, we analyzed 69 patients with chronic hepatitis B infection who were treated with lamivudine (LAM) and followed prospectively for at least 12 months. RESULTS: Of the 69 patients, 12 (17.4%) developed YMDD mutants up to 12 months after the start of LAM. The incidence of YMDD mutants was slightly higher in those who were younger, had higher HBV DNA titers, lower ALT levels, genotype C, and mutations in the core promoter before treatment. However, we could not find any significant factors that correlated with the appearance of the mutants. CONCLUSIONS: Currently, using conventional virological assays, it is difficult to predict the development of mutants before LAM treatment. Management of flare-ups of hepatitis, due to the appearance of mutants, should always be envisaged when LAM treatment is started.