Eu(Ⅲ)/TOPO/Tc体系荧火测定四维素(英文)

本文研究了利用Eu（Ⅲ）－TOPO－Tc体系荧火测定四环素（Tc）的方法及其测定条件．

Conversion of Cellulose to 5-Hydroxymethylfurfural in Water- Tetrahydrofuran and Byproducts Identification

Conversion of cellulose into platform chemical 5-hydroxymethylfurfural （HMF） in water-tetrahydrofuran （THF） co-solvents under acidic condition was studied. 38.6% of HMF was obtained with low cellulose concentration of 2.4wt%, but levulinic acid （LA） and solid humins became the main products with high cellulose concentration. The soluble byproducts were analyzed by high performance liquid chromatography/multiple stage tandem mass spec-trometry, and chemicals with formula of C9H16O4、 C10H14O4、 C11H12O4、C12H10O5 and C12H16O8 were detected. THF could participate in the reaction via ring-opening into 1,4-butanediol followed by esterification with LA into C9H16O4 or etherification with HMF into C10H14O4. C11H12O4 was formed by esterification of HMF with LA, C12H10O5 was formed by self-etherification of HMF, while C12H16O8 was formed by acetalization of HMF with glucose. Self-etherification of HMF and etherification of HMF with 1,4-butanediol were identified as two main side reactions.

Protective Effect of Ascorbate-Lysine on Carbon Tetrachloride and Alcohol-Induced Liver Injury in Mice

As an essential amino acid, lysine boosts protein synthesis (Nestor et al1997). Yao et al demonstrated that, lysine also exerts protective effect against the isch-emiclesion of brain. Meanwhile, vitamin C is a natural antioxidant, which has undisputable protectiveaction against free radical damages. In order to ascertain whether their combination could affordbetter effect, we have investigated the prophylactic effect of the couplant ascorbate-lysine inliver injuries.

Therapeutic effect of interleukin-10 on CCI_4-induced hepatic fibrosis in rats

AIM： To study the therapeutic effect of exogenous interleuldn-10 on CCl4-induced hepatic fibrosis in rats and its passible mechanisms. METHODS： Fourty-seven SD rats were randomly divided into control group （group N） and CCl4-induced hepatic fibrosis model group （group C）. After CCl4 was given for 9 wk, the model group was divided into three groups. Rats in group H were put to death immediately, rats in group T were treated with IL-10 for another three wk and then put to death, rats in group R recovered after three weeks and were then killed. The degree of hepatic fibrosis was measured by HE staining and histological activity index （HAI）. Histological activity index （HAI）, change of collagen types Ⅰ and Ⅲ were measured by Picrosirius staining. The expression of TNF-α, HHP-2 and TIMP-1 in liver tissue was measured by S-P immunohis tochemistry.RESULTS： CCl4- induced experimental rat hepatic fibrosis model was established successfully. The degree of hepatic fibrosis was markedly lower in group T than in groups H and R, and there was no difference between the two groups. The expression of collagen types I and III was significantly suppressed in group T and was slightly suppressed in groups H and R. The positive levels of TNF-α, HHP-2 and TIHP-1 in group H increased significantly compared to those in group N （P〈0.01）. The positive signals decreased significantly in groups T and R （P〈0.01）, but positive score was significantly lower in group T than in group R （P〈 0.01）. CONCLUS10N： Exogenous IL-10 can reverse CCl4-induced hepatic fibrosis in rats. IL-10 may exert its reversible effects on hepatic fibrosis by blocking CCl4-induced inflammation, inhibiting expression of HHP-2 and TIMP-1 and promoting resolution of collagen types Ⅰ and Ⅲ.

Synthesis and Neuroprotective Activity of Novel C4, C7 Derivatives in Tetracycline Series

Since the discovery of the tetracycline in 1953, numerous natural andsemisynthelic tetracyclines have been reported with broad spectrum antibacterial activity .Doxycycline 1 and minocycline 2 are semisyn-thetic second-generation tetracyclines that exertanti-inflammatory effects. These effects appear completely separate and distinct fromtheirantimicrobial actio. Minocycline and doxycycline are absorbed rapidly and show higher brainpenetrability than other tetracyclines. During recent years, doxycycline and minocycline have shownto have neuroprotective effects in models of global and focal ischemia . The neuroprotective effectsare assumed to result from the inhibition of microglia activation. Furthermore, from an in vitrostudy, it was reported that minocycline induces neuroprotection against NMDA-induced neurotoxicityby inhibiting p38 MAP ki-nase activity in microglia . However, neuroprotective mechanisms andstructure-activity relationships of these compounds in neurons are unclear.

Effect of B vitamin supplementation on plasma homocysteine levels in celiac disease

AIM: To investigate the effect of vitamin supplements on homocysteine levels in patients with celiac disease. METHODS: Vitamin B6, folate, vitamin B12, and fasting plasma homocysteine levels were measured in 51 consecutive adults with celiac disease [median (range) age 56 (18-63) years; 40% men, 26 (51%) had villous atrophy, and 25 (49%) used B-vitamin supplements] and 50 healthy control individuals matched for age and sex. Finally, the C677T polymorphism of 5,10-methylene tetrahydrofolate reductase (MTHFR) was evaluated in 46 patients with celiac disease and all control individuals. RESULTS: Patients with celiac disease and using vitamin supplements had higher serum vitamin B6 (P = 0.003),folate (P < 0.001), and vitamin B12 (P = 0.012) levels than patients who did not or healthy controls (P = 0.035, P < 0.001, P = 0.007, for vitamin B6, folate, and vitamin B12, respectively). Lower plasma homocysteine levels were found in patients using vitamin supplements than in patients who did not (P = 0.001) or healthy controls (P = 0.003). However, vitamin B6 and folate, not vitamin B12, were significantly and independently associated with homocysteine levels. Twenty-four (48%) of 50 controls and 23 (50%) of 46 patients with celiac disease carried the MTHFR thermolabile variant T-allele (P = 0.89). CONCLUSION: Homocysteine levels are dependent on Marsh classification and the regular use of B-vitamin supplements is effective in reduction of homocysteine levels in patients with celiac disease and should be considered in disease management.

The alleviating effect of quercetin on carbon tetrachloride-induced liver fibrosis in rats and its underlying mechanism

Quercetin, a phenolic phytochemical widely present in vegetables and fruits, has antioxidant, anti-inflammatory, antiviral, and immunomodulatory activities, and it has been successfully used in the treatment of acute and chronic diseases. In the present study, we aimed to investigate the alleviation effect of quercetin on rat liver fibrosis and explore its mechanism of action. Healthy male SD rats were randomly divided into the normal group, model group, and quercetin group, with six rats in each group. Liver fibrosis was induced by intraperitoneal injection of 1 m L/kg carbon tetrachloride(50% v/v in olive oil) twice a week for 6 weeks, and quercetin(100 mg/kg/d) was administered orally in the 7th week until the end of the 12th week. Blood and liver samples were collected at 1 h after the last administration. Serum liver function parameters(AST, ALT, ALP, GGT, and TBA) were detected by an automatic biochemical analyzer. H&E, Masson, and Sirius red staining were used to observe the pathological morphology of liver tissue. Western blotting analysis was used to evaluate the expressions of liver fibrotic factors(TGF-β1, α-SMA, MMP2, and MMP9) and bile acid-related regulatory proteins(FXR, CYP7A1, CYP8B1, and CYP27A1). The oxidative stress markers(GSH, GSH-Px, GR, SOD, and MDA) in the liver tissue were detected using corresponding kits. The contents of bile acids in the liver tissue were determined by LC-MS/MS. The results showed that compared with the model group, quercetin treatment could significantly reduce serum AST, ALT, and TBA levels(P < 0.05). The fibrotic liver injury was significantly improved, and the expressions of fibrotic factors TGF-β1, α-SMA, MMP2, and MMP9 were significantly decreased(P < 0.05). Liver GSH, GSH-Px, GR, and SOD levels were significantly increased(P < 0.05), and the MDA level was significantly decreased(P < 0.05). The contents of hepatic bile acids were significantly decreased(P < 0.05), the expression of FXR was significantly increased(P < 0.05), and the expressions of CYP7A1 and CYP8B1 were significantly decreased(P < 0.05). This study suggested that quercetin could effectively alleviate carbon tetrachloride-induced liver fibrosis injury, and its mechanism of action was related to improving the liver’s ability to resist oxidative stress and reducing the expressions of fibrotic factors and bile acid synthesis.