As the rapid development of economy necessitates a large number of oil, the contradiction between energy supply and demand is further exacerbated by the dwindling reserves of petroleum resource. Therefore, the research of the renewable cellulosic biomass resources is gaining unprecedented momentum. Because xylose is the second most abundant monosaccharide after glucose in lignocellulose hydrolyzes, high-efficiency bioconversion of xylose becomes one of the vital factors that affect the industrial prospects of lignocellulose application. According to the research progresses in recent years, this review summarized the advances in bioconversion of xylose, which included identification and redesign of the xylose metabolic pathway, engineering the xylose transport pathway and bio-based chemicals production. In order to solve the energy crisis and environmental pollution issues, the development of advanced bio-fuel technology, especially engineering the microbe able to metabolize xylose and produce ethanol by synthetic biology, is environmentally benign and sustainable.
Bacteria ; genetics ; metabolism ; Escherichia coli ; genetics ; metabolism ; Ethanol ; metabolism ; Fermentation ; Fungi ; genetics ; metabolism ; Industrial Microbiology ; methods ; Metabolic Engineering ; Metabolic Networks and Pathways ; genetics ; Saccharomyces cerevisiae ; genetics ; metabolism ; Xylose ; metabolism

BACKGROUND: Long-term excessive intake of beer might lead to change of intra-corporal tissue or activity of serum enzyme.OBJECTIVE: Observation on relations between intake of beer and fat synthesis of rats and activity of enzyme correlated with catabolism in rats.DESIGN: Matched observations randomly of animal experiments.SETTING: Basic Medical Institute of Taishan Medical College.MATERIALS: The experiments were completed in Basic Medical Institute of Taishan Medical College from December 2004 to February 2005. Totally 60 SD rats were selected and categorized into 6 groups with 10 rats in each group. The rats were perfused with 9 mL/kg, 18 mL/kg, 27 mL/kg, 36 mL/kg, and 45 mL/kg beer respectively according to their fat; The rats in control group were fed with water in stead of beer.METHODS: All rats in each groups were narcotized and executed after continuous feeding 1 week, biochemical analysis and enzyme assay were made respectively after blood samples were adopted, and liver, subcutaneous fat, mesentery fat tissue and gastrocnemius muscle were preserved.MAIN OUTCOME MEASURES: ① The level of fat, blood glucose, insulin and blood-lipid of rats in each group after feeding 1 week . ② The enzymatic activity of liver and fat tissue of rats in each group after feeding 1 week . ③ The activity of hormone sensitive lipase and lipoprotein lipase (LPL) of rats in each group after feeding 1 week.RESULTS: Totally 60 rats were channeled into result analysis without any loss. ① Comparison of the levels of fat and biochemical specifications of rats in each group after feeding 1 week: The contents of fat, serum free fatty acid (FFA), high-density of lipoprotein (LP) cholesterol, hepar triacylglycerol and liver cholesterol in beer 36 mL/kg group were higher than those in control groups (x2=19.44-20.01, P ＜ 0.01). ② Comparison of the levels of the enzymatic activity of liver and fat tissue of rats in each group after feeding 1 week: The activities of liver, subcutaneous fat, and liver microsome, I.e. Triacylglycerol alternation protein, phosphatidyl phosphohydrolase, malic enzyme, glucose-6-phasphate dehydrogenase (G6PD) of mesentery tissue in beer 36 mL/kg group were higher than those in control groups (x2=15.02-16.00, P ＜ 0.05). ③ The comparison on level of the activity of hormone sensitive lipase and lipoprotein lipase (LPL) of rats in each group after feeding 1 week: The activity of gastrocnemius muscle of hormone sensitive lipase in beer 36 mL/kg group were prominently lower than those of control groups (P ＜ 0.01), but the activity of lipoprotein lipase (LPL) (P ＜ 0.01) of subcutaneous fat were prominently higher than those in control groups (P ＜ 0.01). The activities of lipoprotein lipase (LPL)of mesentery fat tissue, subcutaneous fat and gastrocnemius muscle tissue in beer 36 mL/kg group were prominently higher than those in other beer groups and control groups (x2=19.00-20.00, P ＜ 0.01).CONCLUSION: The intake of a certain amount of beer (36 mL/kg) might promote the capability of liver in synthesis and the transport of triacylglycerol in rats. The acceleration of lipid synthesis and storage of fat tissue such as mesentery fat tissue and the increase of fat decomposition and mobilization in peripheral tissue such as muscular tissue and subcutaneous fat would finally lead to the increase of fat.

Objective To design simulated pulmonary air embolism demonstration model,so as to solve the problem of pathological anatomy of pulmonary air embolism in experiment teaching. Methods According to the principle of the disturbance of local blood circulation and air embolism, we designed a pulmonary air embolism model. We took 223 school nursing students as the object of this study,and randomly divided them into 2 groups:animal experiment teaching group and model control group,then we compared the teaching effect between the two groups. Result The test scores of students in the animal experiment teaching group were higher than control group (P<0.05) . Conclusion The use of simulated pulmonary air embolism demonstration model teaching can improve the students’experimental test scores,and can be repeatedly used,stimulate students' study interest,reduce the cost of teaching,and improve the teaching quality.

The authors analyzed the status quo of the indicators, outcomes and uses,methodology, procedures and technologies of the variations management of clinical pathways in China the abroad. The outputs of the study point to the following assignments in such a management, such as further identification of the contents of such variations, and further clarification of variation analysis indicators.

Objective To summarize the experiences in laparoscopic inguinal hernia repairing for adult patients. Methods Clinical data of 512 hernia cases admitted in our center from March 2007 to Sep 2010 were retrospectively analyzed.There were 437 cases of single-sided hernia,including 281 indirect inguinal hernia,86 direct inguinal hernia,15 femoral hernia,16 combined inguinal hernia and 39 recurrent hernia.There were also 75 cases of double-sided inguinal hernia,including 3 recurrent hernia.There were 41 acute incarcerated hernia cases.The average postoperative follow up time was(29 ± 12) months. Results 507 cases underwent successful laparoscopic repair,and 5 cases were converted to open procedure.There were 238 TAPP and 269 TEP in laparoscopic operations.The average operative time for TAPP was (69 ±19) min,and (58 ±15) min for TEP.The average length of postoperative stay was (5.0 ± 1.5) days.The percentage of resuming normal activity after 2 weeks and 4 weeks were 95.7％ (485/507) and 99.0％(502/507).The most common postoperative complications were seroma (9.7％,49/507),transient paresthesia (4.1％,21/507) and chronic pain (0.8％,4/507).The recurrence rate was 0.6％ (3/507).Conclusions Laparoscopic repair of inguinal hernia has the advantage of less trauma,faster recovery,and lower recurrence rate.

Objective To study interleukin-1 receptor(IL-1R) and connexin(Cx36) gene expression following Mg 2+-free-induced seizures in cultured developing neuron. Methods Rat embryo cortical neurons cultured for 6 and 17 days were exposed to Mg 2+-free media to induce seizure. At different time after Mg 2+-free treatment, real-time RT-PCR was used to detect IL-1R and Cx36 mRNA expression. Results 1. IL-1R mRNA expression transiently decreased after Mg 2+-free treatment in neurons cultured for 6 and 17 days in vitro. Then the levels of IL-1R mRNA expression recovered in neurons cultured for 6 days, but IL-1R mRNA expression were increased in neurons cultured for 17 days compared with control group and the peak was at 24 hours. 2. In neurons cultured for 6 days in vitro, Cx36 mRNA expression increased after Mg 2+-free treatment compared with control group, the peak was at 24 hours. But in neurons cultured for 17 days in vitro, Cx36 mRNA expression decreased at 6 hours after Mg 2+-free treatment compared with control group, the peak was at 24 hours. Conclusions IL-1R mRNA and Cx36 mRNA expression following Mg 2+-free-induced seizures are different between the neurons cultured for 6 and 17 days in vitro. This is possibly related to the different neuron injury between 6 and 17 days in vitro following seizures.

BACKGROUND:Titanium and titanium aloy are used mostly in artificial joints, fracture fixation, and oral transplantation, while there are complex cases of insufficient bone mass in these areas. The deepened research of stem cels offers a solution for bone injury to promote new bone formation. The biocompatibility of titanium and stem cels and optimization of titanium surface modification have aroused people's attention. OBJECTIVE:To investigate whether the biocompatibility of titanium and human adipose-derived mesenchymal stem cels can be improved by type I colagen modification of titanium sheets. METHODS:The experiment was divided into two groups. Modification group: titanium sheet was modified with type I colagen; control group: titanium sheet was not modified with type I colagen. Human adipose-derived mesenchymal stem cels at passage 6 were implanted into titanium sheet in two groups. Then we calculated the number of adherent cels in two groups at 1, 2 and 4 hours after implantation, and compared the celladhesion rate. MTT assay was used to observe the proliferation of cels on titanium sheet at 2, 4, 6 and 8 days after implantation. DNA and protein content of cels were detected at 3, 6, 9 days after implantation. The growth of human adipose-derived mesenchymal stem cels seeded upon the titanium sheets was observed under scanning electron microscope at 6 days. RESULTS AND CONCLUSION:When the cels were cultured for 1 hour and 2 hours, the number of adherent cels in the modification group was higher than in the control group (P < 0.05). The absorbance of cels in two groups was increased as the culture time, as detected by MTT assay. The modification group had a significantly higher absorbance value than the control group at 4, 6, 8 days (P < 0.05). DNA and protein contents of the cels in the modification group were higher than that in control group at 6 and 9 days (P < 0.05). At 6 days, the number of adherent cels and secretion of adherent stromal cellmatrix in the modification group were significantly better than that in control group, observed by scanning electron microscopy. Type I colagen modified titanium sheets have good surface activity and biocompatibility, and can promote the proliferation of human adipose-derived mesenchymal stem cels.

OBJECTIVETo investigate the effect of bicuculline, a selective GABAA receptor antagonist, on airway remodeling in the murine model of chronic allergen-induced asthma.

METHODSForty BALB/C mice were randomized into 4 groups, namely the control group, asthmatic model (induced by ovalbumin sensitization and challenge) group, budesonide inhalation group and bicuculline inhalation group. The mice were sacrificed 24 h after the last ovalbumin inhalation, and the lungs were lavaged with PBS and the total cells, eosinophils and lymphocytes counts were examined. Periodic acid-Schiff (PAS) staining was used for counting mucin-positive goblet cells in the lung tissue, and Masson Trichrome staining was used to evaluate collagen deposition. GABAARbeta2 and VEGF were quantified by immunohistochemistry.

RESULTSThe numbers of the total cells, eosinophils and lymphocytes counts in BALF were significantly greater in the bicuculline group than in the control and budesonide groups (P<0.01), but comparable to those in the asthmatic model group (P>0.05). The airway collagen deposition in the bicuculline group was comparable to that in the control and budesonide group (P>0.05), but was significantly less than that in the asthmatic model group (P<0.05). Significant differences were found in the airway histological mucus index between the bicuculline group and the other 3 groups (P<0.05). The airway GABAARbeta2-positive cell percentage in the bicuculline group was significantly greater that those in the control and budesonide (P<0.01 and 0.05), but similar with that in the asthmatic model group (P>0.05). The percentage of pulmonary perivascular VEGF-positive cells in the bicuculline group was significantly greater in the control and budesonide groups (P<0.01 and P<0.05), but comparable to that in the asthmatic model group (P>0.05).

CONCLUSIONGABAARbeta2 is expressed in both the airway epithelium and smooth muscles. Bicuculline inhalation can effectively suppress collagen deposition with a stronger inhibitory effect on mucus hypersecretion than budesonide.

Airway Remodeling ; drug effects ; Animals ; Asthma ; drug therapy ; pathology ; Bicuculline ; therapeutic use ; Disease Models, Animal ; GABA-A Receptor Antagonists ; therapeutic use ; Male ; Mice ; Mice, Inbred BALB C

OBJECTIVETo investigate the correlation between genotypes and biochemical phenotypes of phenylalanine hydroxylase (PAH) in patients with phenylketonuria (PKU).

METHODSThirteen exons and flanking introns of PAH gene in 102 patients with high blood phenylalanine levels (Phe > 120 umol/L) at initial diagnosis were amplified with polymerase chain reaction and analyzed with single strand conformation polymorphism (SSCP), denaturing high performance liquid chromatography (DHPLC) and DNA sequencing. Correlation between genotypes and biochemical phenotypes was analyzed.

RESULTSBiochemical assaying has indicated that 69 patients had classical PKU (Phe> 1200 umol/L), 31 were moderate (Phe 600-1200 umol/L), and 2 were mild (Phe 400-600 umol/L). More than 41 mutations and 75 genotypes have been identified. There were 9 (8.8%) homozygous mutations, which included 3 cases with R111X/R111X, 1 case with IVS4-1G>A/IVS4-1G>A, 3 cases with R243Q/R243Q and 2 cases with V399V/V399V. Among these 8 belonged to classic PKU phenotypes, except for a R243Q/R243Q genotype which has led to a moderate phenotype. In 91 patients carrying compound PAH mutations, 61 were classic, 29 were moderate, and 1 was mild. Patients who were heterozygous for R111X/R243Q and EX6-96A>G(Y204C)/R243Q were found with both classic and moderate PKU phenotypes. Certain individuals who have carried 2 null mutant alleles such as R111X/V399V, EX6-96A>G/Y356X and EX6-96A>G/V399V only showed a moderate phenotype. Individuals with R111X/A165D and R176X/A165D genotypes, on the other hand, respectively presented moderate and classic PKU phenotypes.

CONCLUSIONNinety percent of our patients are compound heterozygotes. Independent assortment of mutant alleles has resulted in a complex genotype-phenotype correlation. Although in most cases a correlation may be found, caution should still be taken upon genetic counseling. The phenomena where similar or even identical genotype may give rise to different biochemical phenotypes have implied that other factors may also influence the phenylalanine metabolism.

Adolescent ; Alleles ; Child ; Child, Preschool ; Exons ; Female ; Gene Frequency ; Genetic Association Studies ; Genotype ; Humans ; Infant ; Infant, Newborn ; Introns ; Male ; Mutation ; Phenotype ; Phenylalanine Hydroxylase ; genetics ; metabolism ; Phenylketonurias ; genetics ; metabolism

Background The incidence of retinal vascular diseases increase annually,such as diabetic retinopathy,retinopathy of prematurity and age-related macular degeneration.The key of treatment for these diseases is how to evaluate retinal vascular change effectively and objectively.Retro-orbital injection of fluorescein isothiocyanatedextran (FITC-dextran) is a simple and effective method for observing C57BL/6J mouse retinal vessels.But,whether it is suitable for other mice and rats is seldom reported.Objective This experiment was to assess the feasibility of the observation of retinal vessels by retro-orbital injection of FITC-dextran in different genus of mouse and offer the reference for relevant study.Methods Twelve animals of C57BL/6J mice,Kunming mice,SD rats and Wistar rats were selected,respectively and divided into the experimental group and control group at average.The right eyes of the animals of the experimental group received the retro-orbital injection of 9 ml/kg FITC-dextran,and the right eyes of animals of the control group received PBS solution at the same volume and way.All the animals were sacrificed 10 seconds after injection and both eyes of each animal were obtained for retinal stretched preparation.The retrobulbar tissue and whole-mount retina were viewed under a fluorescence microscope.The use of the animals complied with Regulation for the Administration of Affair Concerning Experimental Animals by State Science and Technology Commission.Results Retinal blood vessels labeled by FITC-dextran could be observed in both eyes of C57BL/6J mice and Kunming mice to present with a green fluorescence in experimental group under a fluorescence microscope,but no any fluorescence-labeled retinal blood vessel was exhibited in the control mice.The retinal blood vessel could not be observed in all eyes of SD rats and Wistar rats after the injection of FITC-dextran both in the experimental group and the control group under a fluorescence microscope.The surrounding tissues of the right eyes of mice and rats dyed with green fluorescence of FITC-dextran in the experimental group,however,green fluorescence could not be seen in the surrounding tissues of the left eyes of mice and rats.Conclusions Retro-orbital injection of FITC-dextran is a suitable method of observing the retinal vessels of mouse but not rat.