Methyltransferase is an important metabolic enzyme whose main function is to catalyze the methylation of nitrogen, oxygen and sulfur atoms. It plays an important role in the metabolism of exogenous and exogenous compounds, including drugs in vivo. Methyltransferases are widely distributed in different tissues, with the liver and kidneys being the most abundant. In addition, the structure and activity of the enzyme have certain species and individual differences. This article will describe the biological properties of methyltransferases and their role in drug metabolism.

The effects of ketotifen, cimetidine & erythromycin on thebphy-lline pharmacokinetics in rabbits were studied. The results suggested that the elimination half-life of theophylline decresed from 2.74 ? 0.75 to 2.33 ? 0.56 h & the clearance of theophylline increased from 0.15?0.036 to 0.13 ? 0.047 1/kg?h-1 by ketotifen.The elimination half-life of theophylline increased from 2 .08 ? 0.33 to 2.6l?0.45 h & the clearance decreased from 0.2l?0.03 to 0.16?0.03 1/kg?h-1 by cimetidine.The elimination half-life of theophylline increased from 2.39 ? 0.43 to 3.54?0.89 h & the clearance decreased from 0.15?0.03 to 0.12?0.03 1/kg?h-1 by erythromycin.

Corneal endothelial cell(CEC)is the most critical part for the cornea, of which activity can influence the postoperative vision.It is very important for the clinical cornea preservation considering the function and its self-purification of donor cornea.There are a variety of classical methods, which can significantly prolong the saving time of donor cornea with its good quality of CEC.We reviewed the published papers about present preservation methods of cornea, which can give us many suggestions for the clinical cornea preservation.

BackgroundThe effects of extremely low frequency electromagnetic fields (ELF-EMFs) on public health have attracted wide attentions.The association of the thermal effect of ELF-EMFs with cancer and ocular tissue damage has been of concern.However,the pathological changes of scleral tissue after exposure to ELF-EMFs as well as the relationship between these changes and myopia are still poorly understood.ObjectiveThe present study was to investigate the molecular pathological changes of human fetal scleral fibroblasts (HFSFs) after exposure to ELF-EMFs in vitro and to explore the possible mechanism in the occurrence and development of myopia.MethodsHFSFs were cultured and passaged and then exposed to 50 Hz electromagnetic fields,and HFSFs that did not receive the irradiation of ELF-EMFs were used as the control group.The expression of collagen type Ⅰ (COL1A1 ) mRNA and matrix metalloproteinase-2 (MMP-2) mRNA in cultured HFSFs were detected by real-time qualitative polymerase chain reaction (real-time PCR) under different magnetic field intensites (0,0.1,0.2,0.5,1.0 mT) and different exposure time (0,6,12,24,36,48 hours).Cell proliferation assay of HFSFs was detected by the cell counting kit 8 ( CCK8 ) assay.The expression levels of COL1 A1 and MMP-2 proteins in HFSFs were further confirmed by immunofluorescence staining.Results The expression of COL1A1 mRNA was significantly down-regulated under the exposure of 0.2 mT ELF-EMFs for 6 hours,in comparison with the control group;moreover,it decreased in parallel with the increased of flux density (0.099±0.008 vs.0.050±0.004) (P =0.009 ).The expression of MMP-2mRNA was up-regulated conspicuously after exposure to 0.1 mT ELF-EMFs for 24 hours,and it increased with exposure time in comparison with the control group ( 0.009 ±0.001 vs.0.018±0.003 ) ( P =0.038 ).Proliferation of HFSFs (A450) was inhibited following the exposure to 0.2 mT ELF-EMFs for 24 hours in comparison with the control group (P =0.009 ).The expression of COL1 A1 in the experimental group was decreased,compared with the control group,but the expression of MMP-2 was increased.ConclusionsELF-EMFs inhibit the proliferation of HFSFs and expression of COL1 A1 in HFSFs,which might be one of the reasons for the development of myopia.

Humans ; Inservice Training ; Occupational Health ; Safety

Biliary stent has been utilized in the patients of benign and malignant biliary strictures and biliary fistula who are unsuitable or unwilling to operate.Its short-term curative effect is distinct,while the long-term effect is relatively poor,because the long-term application is affected by stent blocking and biliary ducts restenosis.Therefore,the research and development of new biliary stents,such as biodegradable stent and covered stent,are the main trend of the current development,which will be of profound significance for the biliary tract disease.

Objective To observe the clinical efficacy of percutaneous vertebroplasty (PVP) with percutaneous kyphoplasty (PKP) in the treatment of osteoporotic vertebral compression fracture(OVCF) by systematic review. Methods From September 2005 to March 2009,46 cases of fresh OVCF were treated. Patients were divided into 2 groups (A, B), according to Jikei grade, Genant semiquantitative method, injury vertebra number. Twenty-five cases(group A)were treated by PVP,8 males and 17 females with the age of 52 - 78 years (average 69). Vertebra segment of fracture was within T6 - L5 (14 in case thoracical vertebrae and 11 lumbar vertebrae). Twenty-one cases(group B)were treated by PKP,There were 6 males and 15 females with the age of 54 - 82 years (average 71). Vertebra segment of fracture was within T6 - L4 (12 in case thoracical vertebrae and 9 lumbar vertebrae). The clinical efficacy, incidence rate of complication, the anterior height of vertebrae body,visual analogue pain scale(VAS) ,ease of pain were measured preoperatively and at 6 weeks, 3 and 6 months and 1 year postoperatively between the two groups. Results All the patients were followed up for 12 -45 months with an average of 23.5 months. The average recovery of anterior height of vertebrae body was respectively(85.95 ± 4.31) % in group A and (93.64 ± 3.35) % in group B,which statistically difference in vertebral height between two groups (P ＜ 0.05). No statistical significant difference was seen in VAS, analgesic durg (AID) and ease of pain complication between two groups (P ＞0. 05). Statistical significant difference was noted in pre-postoperatively between intra-two groups (P ＜0. 05). Conclusions PVP and PKP can quickly relieve pain and enhance vertebral stability in treating thoracolumbar OVCF according to evaluation parameter, and have the similar therapeutic efficacy in treatment of OVCF with minimal invasion. However, PKP is superior in the recovery of vertebral height.

Animals ; Disease Models, Animal ; Facial Neoplasms ; pathology ; Magnetic Resonance Imaging ; Neoplasm Transplantation ; Rabbits

Animals ; Cerebral Cortex ; metabolism ; Disease Models, Animal ; Male ; Mice ; Mice, Inbred Strains ; Morphine Dependence ; metabolism ; Neurotrophin 3 ; metabolism ; Prosencephalon ; metabolism

Objective A method was developed for determination of the total triterpene glycosides in different sea cucumbers.Methods A holostane triterpene glycoside called Echinoside A was taken as the reference standard.Triterpene glycosides were reacted with vanillin and perchloric acid.The sea cucumbers were extracted by 60% ethanol and partitioned between water and n-butanol to gain the total triterpene glycosides.The contents of total triterpene glycosides in 11 kinds of sea cucumbers were determined with the standard curve.And the relationships of the triterpene glycosides content among different sea cucumber species,growth environment,process technique,etc.were discussed by the value of TG/P(triterpene glycosides content /protein content).Results The determination wavelength was confirmed to be 560nm and the standard curve was determined as y-1.3414x-0.0077.The ab-sorbance was of a good linearity in the mass range of 0-0.5mg with R2 =0.9994.The recovery of this method was(99.01?2.82)% and the relative standard deviation was 4.68%.Conclusion The method has been proved to be convenient,reliable and suitable for the analysis of triterpene glycosides in sea cucumbers.