Copper-Catalyzed Regioselective Sila-Acylation and Silaformylation of 1,3-Dienes Using Esters.

The regioselective sila-acylation and silaformylation of 1,3-dienes was achieved over a copper catalyst using a silylborane as a silyl source. ß,γ-Unsaturated ketones with a (dimethylphenylsilyl)methyl moiety at the α-position were obtained using esters, while ß,γ-unsaturated aldehydes were obtained using formate esters.

Boraformylation and Silaformylation of Allenes.

The boraformylation of allenes with B2 (pin)2 and a formate ester as boron and formyl source, respectively, proceeds in the presence of a copper catalyst. The reaction selectively affords the corresponding ß-boryl ß,γ-unsaturated aldehydes in good to high yields. Furthermore, the silaformylation of allenes was achieved with a formate ester and PhMe2 Si-B(pin) as the silicon source.

Close correlation of liver stiffness with collagen deposition and presence of myofibroblasts in non-alcoholic fatty liver disease.

AIM: Transient elastography is known as a rapid, objective, and highly reliable technique for staging hepatic fibrosis caused by hepatitis C virus infection; however, the relationship between degree of fibrosis and the collagen deposition or the accumulation of myofibroblasts in non-alcoholic fatty liver disease (NAFLD) remains to be further elucidated. METHODS: The subjects were 36 patients with NAFLD who received liver biopsy and liver stiffness measurement using transient elastography. Their clinical data and laboratory values were collected. Morphometric analyses of liver fibrosis indicated by collagen deposition and the relative numbers of myofibroblasts were performed. RESULTS: Liver stiffness measured by transient elastography correlated with histopathological fibrosis staging of NAFLD determined by Brunt's scoring system (P = 0.000149). The fibrosis staging correlated with the ratios of the Sirius red-positive area (P = 0.000032) and α-smooth muscle actin-positive area (P = 0.000898). Finally, liver stiffness significantly correlated with the ratios of the Sirius red-positive area (r = 0.390, P = 0.0184) and α-smooth muscle actin-positive area (r = 0.333, P = 0.0471). CONCLUSIONS: Liver stiffness measurement by transient elastography is valuable for evaluating fibrotic progression in NAFLD.

Usefulness of transient elastography for assessment of liver fibrosis in chronic hepatitis B: Regression of liver stiffness during entecavir therapy.

AIM: The usefulness of transient elastography remains to be validated in chronic hepatitis B, particularly as a tool for monitoring the degree of liver fibrosis during treatment. METHODS: The subjects were 50 patients with chronic hepatitis B virus infection. Liver biopsy was performed in 38 patients, and in 12 patients with platelet counts of 50 × 10(9)/L or less, cirrhosis was clinically diagnosed on the basis of specific signs of portal hypertension. Liver stiffness was measured by transient elastography at baseline and after 12 months of treatment in 20 nucleos(t)ide-naïve patients who started entecavir within 3 months after study entry. RESULTS: Twenty (40%) patients were classified as F1, 10 (20%) as F2, 5 (10%) as F3, and 15 (30%) as F4 (cirrhosis). Median liver stiffness (interquartile range) was 7.0 kPa (5.6-9.4), 9.8 kPa (5.6-14.7), 9.8 kPa (7.6-12.9), and 17.3 kPa (8.2-27.6) in fibrosis stages F1 to F4, respectively. Liver stiffness significantly correlated with fibrosis stage (r = 0.46; P = 0.0014). Of the patients who started entecavir, median liver stiffness significantly decreased from 11.2 kPa (7.0-15.2) to 7.8 kPa (5.1-11.9; P = 0.0090) during 12 months of treatment. Median levels of amino-terminal peptide of type III procollagen and type IV collagen 7S domain in serum significantly decreased from 0.9 (0.6-1.3) to 0.6 (0.5-0.7) U/mL (P = 0.0010) and from 5.0 (4.4-6.7) to 3.9 (3.2-4.4) ng/mL (P = 0.015), respectively. CONCLUSION: Liver stiffness measurement can be useful for monitoring regression of liver fibrosis during entecavir treatment in patients with chronic hepatitis B virus infection.

Usefulness of noninvasive transient elastography for assessment of liver fibrosis stage in chronic hepatitis C.

AIM: To evaluate the method of noninvasive transient elastography for assessment of histological stage of liver fibrosis in patients with chronic hepatitis C (CHC). METHODS: Two hundred and thirty-seven patients with CHC were included in this study. Liver biopsy was performed under ultrasonography on 217 of the patients, excluding twenty with clear clinical evidence of liver cirrhosis. Fifty subjects without liver disease were enrolled as a control group (stage 0). Twenty-five patients with sustained virological response (SVR) to interferon (IFN) therapy were also enrolled. These patients underwent liver biopsy before IFN therapy. Examination of liver stiffness (LS) was performed by elastography. RESULTS: Medians (50% levels) of LS were 4.1 (3.5-4.9), 6.3 (4.8-8.5), 8.8 (6.8-12.0), 14.6 (10.5-18.6), and 22.2 (15.4-28.0), respectively, in the fibrosis stages 0-4 (P < 0.001). LS was significantly correlated with four serum fibrosis markers. LS values in patients with SVR were 3.8 (3.5-5.6), 5.2 (4.4-6.8), 6.8 (6.1-7.6), and 6.1 (3.6-7.9), respectively, in the fibrosis stages 1-4. In all stages, LS for patients with SVR was significantly lower than that for patients who did not undergo IFN therapy. LS was significantly correlated with serum concentrations of hyaluronic acid, type IV collagen, type IV collagen 7S, and type III procollagen N peptide. CONCLUSION: LS correlated well with the histological stage of fibrosis. Changes in liver fibrosis stage may thus be estimated noninvasively using transient elastography.