SPIKE1 Activates the GTPase ROP6 to Guide the Polarized Growth of Infection Threads in Lotus japonicus.

In legumes, rhizobia attach to root hair tips and secrete nodulation factor to activate rhizobial infection and nodule organogenesis. Endosymbiotic rhizobia enter nodule primordia via a specialized transcellular compartment known as the infection thread (IT). The IT elongates by polar tip growth, following the path of the migrating nucleus along and within the root hair cell. Rho-family ROP GTPases are known to regulate the polarized growth of cells, but their role in regulating polarized IT growth is poorly understood. Here, we show that LjSPK1, a DOCK family guanine nucleotide exchange factor (GEF), interacts with three type I ROP GTPases. Genetic analyses showed that these three ROP GTPases are involved in root hair development, but only LjROP6 is required for IT formation after rhizobia inoculation. Misdirected ITs formed in the root hairs of Ljspk1 and Ljrop6 mutants. We show that LjSPK1 functions as a GEF that activates LjROP6. LjROP6 enhanced the plasma membrane localization LjSPK1 in Nicotiana benthamiana leaf cells and Lotus japonicus root hairs, and LjSPK1 and LjROP6 interact at the plasma membrane. Taken together, these results shed light on how the LjROP6-LjSPK1 module mediates the polarized growth of ITs in L. japonicus.

Effect of environmental level of methomyl on hatching, morphology, immunity and development related genes expression in zebrafish (Danio rerio) embryo.

The extensive use of carbamate pesticides has led to a range of environmental and health problems, such as surface and groundwater contamination, and endocrine disorders in organisms. In this study, we focused on examining the effects of toxic exposure to the carbamate pesticide methomyl on the hatching, morphology, immunity and developmental gene expression levels in zebrafish embryos. Four concentrations of methomyl (0, 2, 20, and 200 µg/L) were administered to zebrafish embryos for a period of 96 h. The study found that exposure to methomyl accelerated the hatching process of zebrafish embryos, with the strongest effect recorded at the concentration of 2 µg/L. Methomyl exposure also trigged significantly reductions in heart rate and caused abnormalities in larvae morphology, and it also stimulated the synthesis and release of several inflammatory factors such as IL-1ß, IL-6, TNF-α and INF-α, lowered the IgM contents, ultimately enhancing inflammatory response and interfering with immune function. All of these showed the significant effects on exposure time, concentration and their interaction (Time × Concentration). Furthermore, the body length of zebrafish exposed to methomyl for 96 h was significantly shorter, particularly at higher concentrations (200 µg/L). Methomyl also affected the expression levels of genes associated with development (down-regulated igf1, bmp2b, vasa, dazl and piwi genes), demonstrating strong developmental toxicity and disruption of the endocrine system, with the most observed at the concentration of 200 µg/L and 96 h exposure to methomyl. The results of this study provide valuable reference information on the potential damage of methomyl concentrations in the environment on fish embryo development, while also supplementing present research on the immunotoxicity of methomyl.

[Chemical constituents and pharmacological action of bile acids from animal:a review].

Bile of animal(mainly chicken, pig, snake, cow, and bear) has long been used as medicine. As the major active components of bile, bile acids mainly include cholic acid, deoxycholic acid, chenodeoxycholic acid, ursodeoxycholic acid, and taurochenodeoxycholic acid. They interact with intestinal microorganisms in enterohepatic circulation, thereby playing an important part in nutrient absorption and allocation, metabolism regulation, and dynamic balance. Bile acids have pharmacological effects such as protecting liver, kidney, heart, brain, and nerves, promoting bile secretion, dissolving gallstones, anti-cancer, relieving cough and dyspnea, dispelling phlegm, treating eye diseases, and regulating intestinal function and blood glucose, which are widely used in clinical practice. This study summarized and analyzed the research on the chemical constituents and pharmacological effects of bile acids from medicinal animals, in a bid to provide scientific basis and reference for the further development and utilization of bile acids.

Bacterial Community Structure and Diversity in the Aqueous Environment of Shihou Lake and its Relationship with Environmental Factors.

Microorganisms are sensitive to changes in the external environment and are often used as indicators to monitor and reflect water quality. Using Illumina MiSeq sequencing, the characteristics of the microbial community in Shihou Lake water at different time points were analyzed and the key environmental factors affecting the bacterial community were identified. The microbial community diversity in Shihou Lake water was rich and showed significant differences over time. The main bacterial phyla were the Cyanobacteria, Proteobacteria, Actinobacteria, Verrucomicrobia, Bacteroidetes, Chloroflexi, Planctomycetes, Firmicutes, Chlorobi, WS6 and Saccharibacteria. The relative abundance of these major phyla in the sample accounted for 97.83%-99.07% of the total abundance; Cyanobacteria had the highest relative abundance, accounting for 13.07%-44.61% of the total, and the abundance of each dominant phylum was significantly different at different time points. The Shannon and Simpson indexes showed that the diversity of each month was as follows: August > October > July > September > November. The Chao1 and Ace indexes indicated that the order of richness was: November > October > July > August > September. Beta diversity analysis found significant differences in the samples from month to month. Environmental factors such as temperature, total nitrogen, chlorophyll-a, permanganate index, nitrite, pH and ammonia nitrogen had significant effects on microbial community structure.

Ultrasonographic evaluation of gastric emptying after ingesting carbohydrate-rich drink in young children: A randomized crossover study.

BACKGROUND: A recent consensus statement in Europe has suggested that the fasting time for clear liquid in children can be shortened to 1 hour before a surgery. However, the study to show that 1-hour fasting time for clear fluids is safe in young children is still lacking. This study aimed to investigate the gastric emptying time for carbohydrate-rich drink and regular 5% glucose solution in children aged 3-7 years. METHODS: After overnight fasting, individuals were randomly assigned to ingest 5 mL kg-1 of either carbohydrate-rich drink or 5% glucose solution. One week later, the same subjects were asked to ingest the other one. Ultrasonography was performed to examine the gastric contents. Gastric antral cross-sectional area was measured, and the gastric fluid volume was calculated before and after fluid ingestion within 120 minutes. The primary outcome was the gastric emptying time for both the clear fluids calculated using the antral cross-sectional area and logarithms of gastric fluid volume. The degrees of thirst and hunger of two drinks were evaluated using a visual analogue scale as the secondary outcomes. RESULTS: Data from 16 individuals were analyzed. In the glucose solution group, the antral cross-sectional area and logarithms of gastric fluid volume returned to baseline at 30 minutes after ingestion. However, in the carbohydrate-rich drink group, the median [interquartile range; range] antral cross-sectional area (3.69 [2.64-5.15; 1.83-8.93] cm2 vs 2.41 [2.10-2.96; 1.81-4.37] cm2 , P < .001) and mean (95% confidence interval) logarithms of gastric fluid volume (2.54 [2.30-2.79] mL vs 2.12 [1.94-2.30] mL, P = .048) were still higher than at 60 minutes and returned to the baseline values at 90 minutes after ingestion, respectively. The degree of thirst was lower in the glucose solution group than that in the carbohydrate-rich drink group. CONCLUSIONS: Gastric emptying of carbohydrate-rich drink is slower than that of 5% glucose solution but the residual gastric fluid volume is low one hour after ingestion of 5 mL kg-1 of either fluid.

Effect of Chronic Exposure to Methomyl on Tissue Damage and Apoptosis in Testis of Tilapia (Oreochromis niloticus) and Recovery Pattern.

Tilapia were exposed to 0, 0.2, 2, 20, 200 µg/L methomyl for 30 days, and then transferred to methomyl-free water for 18 days. Caspase-8 in serum, apoptosis rate, microstructure and ultra-microstructure of testis were checked after methomyl exposure and at 18 days after transferring to methomyl-free water. There were no significant changes in Caspase-8 activity, apoptosis rate, and tissue structure in testis exposed to 0.2 and 2 µg/L compared with control. However, when tilapia exposed to 20 and 200 µg/L, the Caspase-8 activity and apoptosis rate were induced significantly, and tissue damage happened compared with the control. Thus it would appear 2 µg/L methomyl might be considered as the no observed adverse effect level. Recovery data showed that the effects produced by lower concentration of 20 µg/L were reversible but not at the higher 200 µg/L concentration.

Effect of methomyl on sex steroid hormone and vitellogenin levels in serum of male tilapia (Oreochromis niloticus) and recovery pattern.

Tilapia were exposed to sub-lethal concentrations of 0, 0.2, 2, 20 or 200 µg/L for 30 days, then transferred to methomyl-free water for 18 days. E2 , T, 11-KTand VTG in serum were examined. There were no significant changes in all the parameters in serum of tilapia exposed to 0.2 µg/L and 2 µg/L methomyl compared to the control. However, 20 µg/L and 200 µg/L have the potential to disrupt the endocrine system of male tilapia, as shown by its ability to increase VTG and E2 and decrease T and 11-KT in serum. Thus it would appear the no observed adverse effect level for sexual steroid hormones of methomyl is lower than 2 µg/L. Recovery data showed that the effects produced by 20µg/L were reversible but not at 200µg/L. Furthermore, the sensitivity of above parameters to methomyl followed the order of VTG>E2 >11-KT>T>GSI, suggesting VTG being the better biomarkers.

Responses and recovery pattern of sex steroid hormones in testis of Nile tilapia (Oreochromis niloticus) exposed to sublethal concentration of methomyl.

Tilapia were exposed to sublethal methomyl concentrations of 0, 0.2, 2, 20 or 200 µg/L for 30 days, and then transferred to methomyl-free water for 18 days. The sexual steroid hormones 17ß-estradiol (E2), testosterone (T), and 11-ketotestosterone (11-KT) in tilapia testes were examined at 0, 6, 12, 18, 24 and 30 days after methomyl exposure, and at 18 days after fish were transferred to methomyl-free water. There were no significant changes in the hormone parameters in testes of tilapia exposed to low concentration 0.2 and 2 µg/L methomyl compared with the controls. However, high concentration 20 and 200 µg/L methomyl had the potential to disrupt the endocrine system of male tilapia, as shown by an increase in E2 and a decrease in T and 11-KT in the testes. Thus, it would appear that the 2 µg/L methomyl might be considered the no-observed-adverse-effect level. Recovery data showed that the effects produced by the lower concentration of 20 µg/L were reversible but the effects were not reversible at the higher concentration of 200 µg/L.

Responses of glutathione-related antioxidant defense system in serum of Nile tilapia (Oreochromis niloticus) exposed to sublethal concentration of methomyl and recovery pattern.

Tilapia were exposed to sublethal concentrations of 0, 0.2, 2, 20, or 200 µg/L for 30 days, and then transferred to methomyl-free water for 18 days. GST, GPx, GR, GSH, and GSSG in tilapia serum were examined at 0, 6, 12, 18, 24, and 30 days after methomyl exposure and at 18 days after transferring to methomyl-free water. There were no significant changes in antioxidants activities and contents in serum of tilapia exposed to 0.2 µg/L. Significant increases in GST, GR, GPx, and GSSG accompanied by a decrease in GSH were observed following methomyl exposure to 2, 20, or 200 µg/L, suggesting the presence of oxidative stress. Thus, it would appear the 0.2 µg/L methomyl might be considered the no observed adverse effect level. Recovery data showed that the effects produced by lower concentration of 20 µg/L were reversible but not at the higher 200 µg/L concentration.

[Simultaneous quantitative analysis of different ceramide species in cells by high-performance liquid chromatography-tandem mass spectrometry].

OBJECTIVE: To establish a high-performance liquid chromatography-tandem mass spectrometry (HPLC-ESI-MS) method for simultaneous quantitative analysis of different ceramide species in cells. METHODS: The analysis was performed on an Agilent 1290 HPLC system with a ZORBAX Eclipse XDB-C8 (150.0 mm × 2.1 mm, 3.5 µL) column and a temperature of 35 ℃. Methanol with 1 mmol/L ammonium formate and 0.2% formic acid was used as mobile phase A and 100% methanol was used as mobile phase B. And the ceramides were separated by gradient elution at a flow rate of 0.3 mL/min. Electrospray ionization (ESI) with multiple reaction monitoring (MRM) was used in the analysis. RESULTS: Four ceramide species all had a good linear response in the determination ranges (R² ≥ 0.9987). The average recoveries (n = 9) were 99.1%,99.9%,100.5% and 98.2% with RSDs of 5.6%, 5.1%, 4.7% and 5.5%, respectively. In addition, the levels of ceramides in FL cells were relatively stable, while the C24-ceramide had the highest level. CONCLUSION: The HPLC-ESI-MS method for simultaneous analysis of ceramides has high accuracy, reproducibility and linearity, which may be used for quantification of ceramide species in cells.

Effects of chronic exposure of methomyl on the antioxidant system in liver of Nile tilapia (Oreochromis niloticus).

The chronic effect of methomyl on the antioxidant system in tilapia (Oreochromis niloticus) was investigated. Fish were exposed to sub-lethal concentrations of 0.2, 2, 20 and 200µgL(-1) for 30 days, and then transferred to methomyl-free water for 18 days. Hepatic antioxidant parameters, including Glutathione-S-transferase (GST), Glutathione peroxidase (GPx), Glutathione reductase (GR), Reduced glutathione (GSH) and oxidized glutathione (GSSG), were measured at 10min (day 0), 6, 12, 18, 24 and 30 days after starting the experiment and at 18 days after transferring to methomyl-free water. There were no significant changes in enzymatic activity and content of antioxidants in liver of tilapia exposed to 0.2µgL(-1) methomyl compared to controls. However, the results showed significant increases in activities of GST, GR, GPx and levels of GSSG accompanied by a decrease in GSH levels following methomyl exposure in tilapia to 2, 20 or 200µgL(-1) over the 30-day exposure period and the highest induction rates in GST, GR, GPx and GSSG were 150.87%, 163.21%, 189.76%, and 179.56% of the control respectively, and the highest inhibition rate in GSH was 50.67% of the control, suggesting the presence of oxidative stress. Thus it would appear that the 0.2µgL(-1) methomyl might be considered as the no observed adverse effect level (NOAEL). Recovery data showed that the effects produced by lower concentration of methomyl 20µgL(-1) were reversible but not at the higher 200µgL(-1) concentration.

Hepatic antioxidant enzymes SOD and CAT of Nile tilapia (Oreochromis niloticus) in response to pesticide methomyl and recovery pattern.

Hepatic antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT) of Nile tilapia in response to pesticide methomyl and recovery pattern were researched by exposing tilapia to sub-lethal methomyl concentrations of 0, 0.2, 2, 20 and 200 µg/L for 30 days, and then transferred to methomyl-free water for 18 days. Hepatic SOD and CAT were measured at 10 min (day 0), 6, 12, 18, 24 and 30 days after starting the experiment and at 18 days after transferring to methomyl-free water. The results showed hepatic SOD and CAT activities in 2, 20 and 200 µg/L groups were affected significantly, however, that in 0.2 µg/L group didn't change significantly compared to control during 30-day exposure period. Thus it would appear the 0.2 µg/L methomyl might be considered the no observed adverse effect level. Recovery data showed that, for SOD, the effects produced by lower concentration of methomyl 2 µg/L were reversible but not at concentrations higher than 20 µg/L, however, for CAT, the effects produced by all the concentrations were reversible.

[Distribution of Typical Resistant Bacteria and Resistance Genes in Source Water of the Middle and Lower Reaches of the Yellow River].

The Yellow River water of an urban area located in the middle and lower reaches of the Yellow River was taken as the research object， in which the seasonal and along-range distribution of total culturable bacteria， typical antibiotic resistant bacteria （amoxicillin resistant bacteria and sulfamethoxazole-resistant bacteria）， and their corresponding typical resistance genes ï¼»ß-lactam resistance gene （blaCTX-M） and sulfamamide resistance genes （sulI and sulⅡ）， as well as intⅠ1 were investigated. The results showed that the total culturable bacteria， ß-lactam-resistant bacteria and sulfonamide-resistant bacteria in the Yellow River Basin were significantly affected by temperature and human activities. The composition and quantity of their genera had obvious spatiotemporal distribution characteristics， in which Bacillus and Pseudomonas were dominant in the composition and number of bacteria. The abundance of resistance genes decreased with the decrease in temperature. The proportion of ß-lactam resistance genes in the total genes was higher than that of sulfanilamide genes， and sulI was the dominant gene in sulfanilamide genes. Correlation analysis showed that class Ⅰ integron played an important role in accelerating the spread of resistance genes. This study offers insight into the status quo of water resistance pollution in the Yellow River and provides theoretical support for the risk assessment of resistance genes in the middle and lower reaches of the Yellow River Basin.

Effects of chronic exposure of methomyl on the antioxidant system in kidney of Nile tilapia (Oreochromis niloticus) and recovery pattern.

Tilapia were exposed to sublethal methomyl concentrations of 0, 0.2, 2, 20, or 200 µg/L for 30 d, and then were transferred to methomyl-free water for 18 d. Renal antioxidant parameters, including catalase (CAT), superoxide dismutase (SOD), glutathione S-transferase (GST), glutathione peroxidase (GPx) , glutathione reductase (GR), total glutathione (GSH), and reduced glutathione (GSSG), were examined in tilapia at d 0, 6, 12, 18, 24, and 30 after starting the experiment and at 18 d after transferring to methomyl-free water. There were no significant changes in enzymatic activity and content of antioxidants in kidney of tilapia exposed to 0.2 µg/L methomyl compared to controls. The results showed significant increases in SOD, CAT, GST, GR, GPx, and level of GSSG accompanied by a decrease in GSH levels following methomyl exposure in tilapia to 2, 20, or 200 µg/L over the 30-d exposure period, suggesting the presence of oxidative stress. Thus, it would appear the 0.2 µg/L methomyl might be considered the no-observed-adverse-effect level (NOAEL). Recovery data showed that the effects produced by lower concentration of methomyl at 20 µg/L were reversible but not at the higher 200 µg/L concentration.

[Analysis of small supernumerary marker chromosome 15q11 in four infertile males].

OBJECTIVE: To delineate the origins of small supernumerary marker chromosomes (sSMCs) identified in 4 infertile males. METHODS: The sSMCs were analyzed with combined G-banding, N-banding, multiplex ligation-dependent probe amplification (MLPA), fluorescence in situ hybridization (FISH) and single nucleotide polymorphisms array (SNP-array) techniques. RESULTS: G-banding analysis has suggested a 46,X,-Y,+mar karyotype in all of the 4 cases. N-banding revealed that all of the sSMCs have possessed two satellites located on both sides. By MLPA, 1 patient showed copy number gains for 15q11.2 region. SNP-array analysis suggested that all had duplication for 15q11.1-q11.2 region, spanning 3.06 Mb, 0.9118 Mb, 1.728 Mb and 0.287 Mb, respectively. By FISH analysis, all of the sSMCs showed two hybridization signals, indicating that they were dicentric chromosomes. CONCLUSION: In all of the four cases, the marker chromosomes have derived from chromosome 15 and were bisatellited and dicentric, which gave rise to a karyotype of 47,XY,+ish,inv dup(15)(q11)(D15Z4++). sSMC 15q11 therefore may be a major cause for male infertility.

Bear bile powder ameliorates type 2 diabetes via modulation of metabolic profiles, gut microbiota, and metabolites.

Introduction: Bear bile powder (BBP) is widely used in the clinic and has a hypoglycemic effect, but its mechanism is not clear. Methods: In this study, type 2 diabetes mellitus (T2DM) rats induced by a high-sugar and high-fat diet combined with streptozotocin were given BBP, and biochemical indexes, pathological sections, metabonomics, intestinal microbiota (IM) and short-chain fatty acids (SCFAs) were determined. Results: The results showed that BBP could reduce blood glucose, relieve inflammation, insulin resistance, and lipid metabolism disorder, and alleviate tissue damage of the liver, spleen, kidney, and pancreas in T2DM rats. It is worth noting that BBP can reverse the changes in blood and urine metabolites in T2DM rats, which are mainly related to tryptophan metabolism, pentose and glucuronate interconversions, starch and sucrose metabolism, and glycerophospholipid metabolism. In addition, BBP restored IM disorder in T2DM rats, decreased the abundance of Allobaculum, Blautia, Dubosiella, and Anaerostipes, enriched the abundance of Lactobacillus, Romboutsia, UCG-005, and norank_f__Eggerthellaceae, and increased the concentration of SCFAs in intestinal contents. Discussion: These findings suggest that BBP may improve T2DM by regulating multiple metabolic pathways, IM composition, and SCFAs levels.

Highly sensitive and selective bifunctional oligonucleotide probe for homogeneous parallel fluorescence detection of protein and nucleotide sequence.

The existing isothermal polymerization-based signal amplification assays are usually accomplished via two strategies: rolling circle amplification (RCA) and circular strand-displacement polymerization. In essence, the two techniques are based on cyclical nucleic acid strand-displacement polymerization (CNDP), limiting the application of isothermal polymerization in medical diagnosis and bioanalysis. In the present study, circular common target molecule (non-nucleic acid strand)-displacement polymerization (CCDP) is developed to amplify the fluorescence signal for biomolecule assays, extending isothermal polymerization to an aptameric system without any medium. Via combining an aptamer with a common hairpin DNA probe, we designed a self-blocked fluorescent bifunctional oligonucleotide probe (signaling probe) for the homogeneous parallel detection of two disease markers, PDGF-BB and the p53 gene. On the basis of CNDP and CCDP signal amplification, highly sensitive (e.g., detecting PDGF down to the concentration level of 1.8 × 10(-10) M) and selective detection (no interference even in the presence of a significantly higher concentration (7-200 times) of nontarget proteins) was accomplished, and the linear response range was considerably widened. Furthermore, the bifunctional signaling probe exhibits impressive simplicity, convenience, and short detection time. Herein, the design of the signaling probe was described, factors influencing fluorescence signal were investigated, analytical properties were characterized in detail, and the assay application in a complex medium was validated. The proposed biosensing scheme as a proof-of-concept is expected to promote the application of oligonucleotide probes in basic research and medical diagnosis.

Effect of vascular endothelial growth factor 165 gene transfection on bone defects and its mRNA expression in rabbits.

BACKGROUND: Gene therapy has been a hot spot in repair of bone defects in recent years. This study aimed to construct a recombinant plasmid pcDNA3.1-VEGF(165), and to observe the effect of vascular endothelial growth factor 165 (VEGF(165)) gene therapy on bone defects in rabbits. METHODS: Total RNA was extracted from rabbit bone tissues. VEGF(165) cDNA fragment was prepared by reverse transcription and the gene was cloned by polymerase chain reaction (PCR). Plasmid pMD18-T/VEGF(165) combined with pcDNA3.1 was cloned to reconstruct pcDNA3.1-VEGF(165) plasmid. Thirty New Zealand white rabbits weighing (2.50 +/- 0.13) kg were used to establish models of bone defects (1 cm in length) of the bilateral radii. The bone defects were repaired with absorbable gelatin sponge. After the operation, physiological sodium chloride solution was injected into the injured site in one of the forelegs of the rabbits as the control group, and pcDNA3.1-VEGF(165) plasmid (0.2 ml, 200 ng) was injected into the opposite foreleg as the experiment groups. At weeks 1, 2, 4, 6, 8, and 12 after the treatments, the bones were examined by X-ray, and the specimens of the bone defects were collected, stained with HE, and observed under a light microscope. The expression of VEGF(165) mRNA was examined by real-time quantitative polymerase chain reaction (RQ-PCR). RESULTS: The pcDNA3.1-VEGF(165) plasmid with a correct sequence was constructed successfully. Postoperative X-ray found no difference between the two groups at week 1. In the experiment group, callus and synostosis were observed after 2 weeks, and osteosis structure was normal at week 12; these phenomena occurred much later in the control group. In the experiment group, HE staining showed a large amount of newly formed blood vessels after 2 weeks, a number of bone trabeculae with osteoblasts proliferation at 4 weeks, and fresh bone cortex and reformed medullary cavity at 12 weeks; whereas in the control group these structures formed in later phases. The VEGF(165) mRNA in the experiment group was expressed at a low level at week 1, reached the peak at weeks 3, and then decreased to a normal level after 6 weeks. CONCLUSIONS: Local use of pcDNA3.1-VEGF(165) plasmid at bone defects can upregulate the expression of VEGF(165) and accelerate the formation of capillaries and the repair of bone defects. Angiogenesis and osteogenesis can be promoted by a combination of pcDNA3.1-VEGF(165) and gelatin sponge.

[Effect of vascular endothelial growth factor 165 gene transfection on repair of bone defect: experiment with rabbits].

OBJECTIVE: To investigate the influence of vascular endothelial growth factor (VEGF) 165 gene transfection on the repair of bone defect. METHODS: 38 New Zealand rabbits underwent resection of a segment 1 cm in length in bilateral radii filled with absorbable gelatin sponge. Dilated solution of the plasmid pcDNA3.1/VEGF165 was injected into the bone defect of one side and normal saline was injected into the contralateral bone defect. 1, 2, 4, 6, 8, and 12 weeks later X ray examination was conducted to observe the repair of bone defect, and then 5 rabbits were killed at each time points to take out the bone defects. HE staining was used to observe the bone repair. The levels of microvessel density (MVD) 1 and 2 weeks after the operation were observed. RT-PCR was used to detect the mRNA expression of VEGF in the bone defect. Based on the results of RT-PCR the tissue mRNA expression of VEGF65 was detected by real-time quantitative polymerase chain reaction (RQ-PCR). RESULTS: X-ray examination showed that there was no significant difference in the wound healing between the two group 1 week after the operation in all rabbits. Some callus could be seen in the experimental group 2 weeks after. Twelve weeks after the operation the reconstruction of bone cortex was completed. Similar process occurred in the control sides but more lately. The MVD level 7 days after of the experimental group was 47.0 +/- 7.5, significantly higher than that of the control group (42.2 +/- 6.4, t = 2.4519, P = 0.0179), and the MVD level 14 days after of the experiment group was 69.1 +/- 5.4, significantly higher than that of the control group (56.1 +/- 6.1, t = 8.0347, P = 0.0000). In the experimental group the mRNA expression amounts of VEGF165 could be found 1 week after, gradually increased and peaked 3 weeks after, then decreased, and became stable 6 weeks after. The mRNA expression amounts of VEGF165 in the control group were lower than those of the experimental group. CONCLUSION: Local application of PcDNA3.1/VEGF(165) vector promotes the expression of VEGF165, and enhances the quantity of the angiogenesis, extra cellular matrix and healing of bone defect.

Reaction mode between Si and Fe and evaluation of optimal species in poly-silicic-ferric coagulant.

A kind of Fe-polysilicate polymer, poly-silicic-ferric (PSF) coagulant was prepared by co-polymerization (hydroxylation of mixture of Fe3+ and fresh polysilicic acid (PS)), in which PSF0.5, PSF1 or PSF3 denotes Si/Fe molar ratio of 0.5, 1 or 3, respectively. The effects of Si/Fe ratio and reaction time (co-polymerization time or aging time) on the reaction mode between Si and Fe were studies, and the optimal species of PSF was evaluated by pH change during the preparation of PSF and coagulation tests. The results showed that the characteristics of PSF are largely affected by both reaction time and Si/Fe ratio. PSF is found to be a essential complex of Si, Fe, and many other ions. The reaction mode between Si and Fe differs with various Si/Fe ratios. The pH of PSF0.5, PSF1 or PSF3 tended to be stable when reaction time is 10, 25 or 55 min, respectively, which is almost consistent with the time reaching the relative stable morphology that is just the optimal species of higher coagulation efficiency. The optimal reaction time reaching optimal species can be evaluated by measuring the pH change during the polymerization process.