This paper reports a method for direct determination of ascorbic acid by ultra-violet differential spectrometry and its application to analysis of ascorbic acid contents in vegetables, fruits and tablets. All the four (1st to 4th) derivatives of spectrometry were available for determination, and the better results were obtained from the 2nd derivative spectrometry. The results showed that this method was simple, rapid and accurate.

Objective:To investigate the protective effect of dimethylsulfoxide(DMSO) on axon degeneration.(Methods: Cultured) rat superior cervical ganglia were treated with DMSO(100%,10 ?l) per well to disconnect axons from the cell bodies.SCGs in DMSO control group were treated with a mixture of DMSO(10 ?l) and medium (2 ml) per well;in positive control group were transfected with herpes simplex virus over-expressing Wld~S protein and the cell body was eliminated;and in blank control group were treated with 10 ?l PBS.The separated axons were fixed with 4% poly formaldehyde at 0,4,8,12 and 24 h after treatment with DMSO for immunostaining with specific antibody to microtubulin.Thus,the changes of axonal structure were investigated.The axonal protein was collected and the degeneration of neurofilament was detected by Western Blotting.Results: In DMSO disconnected group,the axonal morphology and structure showed no obvious change at 12 h post disconnection,but slight degeneration was observed at 24 h post disconnection.The degradation of microtubulin was obviously slowed down and their axonal structures maintained intact 12 h later.The neurofilament could be detected 12 h after disconnection.The above changes in disconnected group were similar to those in positive control group.No obvious protective effects on axonal degeneration were observed in blank and DMSO control groups.Conclusion: Local high concentration of DMSO can delay axonal degeneration,which indicates that DMSO can be used for adjuvant treatment of neurodegenerative diseases.

AIM: To explore the effect of endoplasmic reticulum stress on cardiac myocyte apoptosis in mouse congestive heart failure induced by myocardial infraction.METHODS: The mouse model of heart failure was established by ligating the left anterior descending coronary to produce acute myocardial infarction.Thirty-two mice were divided into 4 groups: sham group and groups of post-operation at time points of 2,4 or 6 weeks,respectively.The ventricular dilatation and left ventricular functions were assessed by echocardiography.The expression of GRP78,CHOP,caspase-12,cleaved caspase-12,JNK and phosphorylated-JNK was detected by Western blotting.The cardiac myocyte apoptosis was determined by terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labeling(TUNEL).RESULTS: The cardiac expression of endoplasmic reticulum chaperones GRP78 was significantly increased in the hearts with functional failure.The upregulated expression of CHOP,phosphorylated-JNK and cleaved caspase-12 illuminated that the CHOP-JNK-caspase-12 dependent pathways for endoplasmic reticulum-initiated apoptosis were activated in the heart with functional failure by myocardial infraction.CONCLUSION: These findings suggest that the congestive heart failure induced by myocardial infraction is associated with endoplasmic reticulum stress and activation of CHOP,JNK,caspase-12 dependent pathways for endoplasmic reticulum-initiated apoptosis.

AIM: To investigate the changes of intracellular calcium ion (Ca2+) concentration in mouse H9c2 (2-1) cells transfected with or without FK506 binding protein 12.6(FKBP12.6) gene by ultrasound mediated destruction of microbubbles. METHODS: The pcDNA3.1-FKBP12.6 plasmid, mingled with albumin-coated microbubbles agents, was transfected into H9c2 (2-1) cells by ultrasound-mediated destruction of microbubbles. The H9c2 (2-1) cell growth state was investigated by inverted microscope. The changes of intracellular Ca2+ concentration was determined by laser scanning confocal microscope. The FKBP12.6 protein expression was checked by immunohistochemistry. RESULTS: As compared with control cells, the H9c2 (2-1) cells, transfected with FKBP12.6 gene, grew better, had higher gross intracellular Ca2+ concentration. CONCLUSION: FKBP12.6 gene augments Ca2+ concentration in mouse H9c2 (2-1) cells, enhances the contractibility of the myocardial cell, which may be helpful to improve the myocardial dysfunction.

Objective To quantitate coronary tortuosity and provide favorable conditions for understanding the hemodynamic effects caused by coronary tortuosity.Methods We obtained all images from 72 patients who received coronary computed tomo-graphy scanning.After image post-processing,we extracted the medial axis of three main coronary vessel and analysed its coordi-nates on three dimensions.Then we calculated the tortuosity coefficient of coronary artery.Results Tortuosity coefficient was 6.66±7.54 in anterior descending,13.43±12.85 in left circumflex,and 1 7.61 ±7.67 in right coronary artery.We had proved its validity by the changes in morphology with simulated shapes.Conclusion We proposed a new method for quantitating coronary tor-tuosity,by computed tomography coronary imaging.The measurement results would not be affected by projection plane,vessel length or other artificial factors.

Keeping an enzyme in its native form with high catalytic activity is of great significance. In the present study, thermal stabilizers of horseradish peroxidase (HRP) were screened. The results indicated that thermal stability of HRP was enhanced by magnesium sulphate and gelatin. A synergic effect of magnesium sulphate and gelatin was observed. In the presence of the stabilizer, the enzymatic activity of HRP remained 89% after kept for 80 h at 50 degrees C and 57% for 90 days at room temperature. Thermal alterations of HRP structure in the absence and presence of the stabilizers were explored by using UV absorption spectra at 402 nm (Soret band), intrinsic fluorescence and 8-anilinonaphthalene-1-sulfonic acid (ANS) fluorescence. The results suggested that magnesium sulphate and gelatin attenuated the extent of unfolding of HRP and therefore the native enzyme structure was stabilized.
Drug Synergism ; Enzyme Stability ; drug effects ; Gelatin ; pharmacology ; Horseradish Peroxidase ; metabolism ; Hot Temperature ; Magnesium Sulfate ; pharmacology

Objective To investigate PSP on bone microstructures,Ca,P,OPG and RANKL of osteoporotic rat model.Methods Thirty female rats randomly divided into five groups:Sham,OVX,H-,M-,L-PSP.Sham and OVX were irrigated stomachsaline;PSP solution was gavaged to other groups.After 8-week,bone microstructures of tibial metaphyseal,Ca,P,OPG and RANKL were measured.Results Body weight,Ca,P,RANKL,Tb.Sp of OVX were significantly increased compared to Sham,OPG,BV/TV,Tb.Th,Tb.N decreased.Body weight of H-,M-PSP,Ca and Tb.Sp of PSP,P and RANKL in H-PSP were decreased compared to OVX,OPG in H-,M-PSP,BV/TV,Tb.Th,Tb.N of PSP group increased.The differences were statistically significant (P ＜ 0.05).Conclusion PSP prevents osteoporosis by improving the microstructure of trabecular bone,reducing bone turnover,increasing OPG and reducing RANKL expression.

Bacillus spp. are probiotics and can secrete a variety of natural antimicrobiol active substances, of which lipopeptides are an important class. Up to now, about 90 lipopeptides have been identified, and most of them are cyclic lipopeptides. surfactin, iturin, fengycin, bacillomycin and polymyxins are widely studied, and the first three have huge potential for application due to their properties of surfactants and anti-fungal, anti-bacterial, anti-viral, anti-tumor and anti-inflammatory functions. In this paper, the research progress in the structure, function, synthesis regulation, separation, purification and production of surfactin, iturin and fengycin was reviewed. Synthetic biology is a vital means to increase the yield of lipopeptides, and in the future, lipopeptides can be used in crop cultivation, animal farming, food, medicine and petroleum industries as well as environmental protection. Future research should be strengthened on the discovery of new lipopeptides, synthesis of high-activity lipopeptides, economical production of lipopeptides on a large scale and their safety evaluation.
Anti-Bacterial Agents ; Anti-Infective Agents/pharmacology* ; Bacillus ; Bacillus subtilis ; Lipopeptides/pharmacology* ; Peptides, Cyclic/pharmacology*