Objective Xenografts have poor biocompatibilities,the aim of this study was to improve the biocompatibilities of decellular xenografts via heparin/dihydroxy-iron complex multilayeres (HDCMs) nanomodification.Methods A novel thrombo-resistant surface for decellular xenograft had been developed by alternating linkage of dihydroxy-iron and heparin to decellular bovine jugular vein (DC-BJV),and surface characterization and biocompatibility of HDCMs nanomodified BJV (HDCMs-BJV) were detected.Results Toluidine blue colorimetric method showed the amount of linked heparin was about (808 ±86) μg/cm2 per assembly-cycle.SEM images proved HDCMs were uniformly linked to and formed nanoscale films around the fibrils of DC-BJV.Washing test proved HDCMs were firmly linked to BJV and sustainedly released heparin for a long time.Tensile test showed that biomechanical stability was increased.Antithrombogenicity test showed that the activated partial thrombin time (APTT) and prothrombin time (PT) of all trial groups were above the normal reference ranges.Platelet adhesion test evaluated mean platelet count per 10 000 μm2 area was 8 ±4 for HDCMs-BJV vs.48 ± 16 for DC-BJV.Endothelial cells (ECs) proliferation test showed the number and activity of ECs on luminal surface of HDCMs-BJV were very similar to DC-BJV at 7-day incubation.Calcium content assay evaluated mean calcium content was ( 8.5 ± 1.9 ) μg/mg dry weight for HDCMs-BJV vs.(26.6 ± 3.7) μg/mg dry weight for DC-BJV at 4 weeks and (21.5 ± 6.8 ) μg/mg dry weight for HDCMsBJV vs.( 112.6 ± 16.9) μg/mg dry weight for DC-BJVs at 8 weeks,respectively.Conclusion These results demonstrate HDCMs were firmly linked to BJV and formed nanoscale thrombo-resistant films,and HDCMs nanomodification improves biocompatibilities of decellular xenograft.

OBJECTIVETo establish the method of detecting the concentrations of chlorpyrifos in air of workplace with high performance liquid chromatographic (HPLC).

METHODSAccording to standards of methods for determining the chemical substances in workplace air, chlorpyrifos in the air was collected by silicone tube, then dissolved by acetonitrile and determined by high performance liquid chromatography with UV-detector.

RESULTSThere was a linear relationship within the range of 0 ∼ 10.0 µg/ml, and regression equation was y = 5206.1x - 104.7, correlation coefficient was 0.9999, the detection limit was 0.006 µg/ml. The lowest detected concentration was 0.001 mg/m(3) (sampling volume 4.5 L). The average recoveries was 98.3% ∼ 102.5%. The within-run precision was 1.96% ∼ 4.39%, the between-run precision was 2.76% ∼ 5.87%. The desorption efficiencies were 99.0% ∼ 103.3% and the sampling efficiencies were 94%. The samples in silicone tube could be stored for 15 days at room temperature.

CONCLUSIONThe present method could meet with the requirements of Guide for establishing occupational health standards-Part 4 Determination methods of air chemicals in workplace and be feasible for determination of chlorpyrifos in workplace air.

Air Pollutants, Occupational ; analysis ; Chlorpyrifos ; analysis ; toxicity ; Chromatography, High Pressure Liquid ; methods ; Limit of Detection ; Reproducibility of Results ; Workplace

Objective To evaluate the values of prenatal surveillances of ultrasonography in twin pregnancies with amniotic fluid discordance. Methods Two hundred and seventy cases of diamniotic twins were included. Both postnatal outcomes and prenatal amniotic fluid discordant variations were analyzed,and the incidences of amniotic fluid discordance were compared between the monochorionic-diamniotic(MCDA)and dichorionic-diamniotic (DCDA) gruop. Results Twenty four cases of twins with amniotic fluid discordance were found in the study. The incidence of amniotic fluid discordance in MCDA group was much higher than that in DCDA group (28.9% vs 5.6%, P ＜0. 001 ) ,and 24 cases of twin-to-twin transfusion syndrome (TTTS) were diagnosed in the former group and none were found in the latter group. Downward tendency of amniotic fluid discordance was shown in non-TTTS cases of MCDA group. Compared with TTTS cases, the postnatal outcomes of non-TTTS cases with amniotic fluid discordance were much better in MCDA group ( P ＜0.001 ). Conclusions TTTS and MCDA twins with amniotic fluid discordance may overlap each other in the early stage. Serial surveillances of ultrasonography are necessary for prenatal differentiating twin pregnancies complicated by amniotic fluid discordance,and providing strong support to clinical treament.

BACKGROUND:The studies have shown that the mesenchymal stem cel s derived from bone marrow and umbilical cord can be continuously cultured in vitro, and maintain the characteristics of stem cel s. The mesenchymal stem cel s can differentiate into hepatocyte-like cel s after“cocktail”induction by various cytokines. OBJECTIVE:To further identify whether umbilical cord-derived mesenchymal stem cel s in vitro co-cultured with normal hepatocytes can differentiate into hepatocyte-like cel s, and to investigate the differentiation method. METHODS:Mesenchymal stem cel s were isolated from human umbilical cord with adherent method, and the surface markers of umbilical cord-derived mesenchymal stem cel s were detected with flow cytometry. The umbilical cord-derived mesenchymal stem cel s were co-cultured with liver LO2 cel s without adding exogenous inducers. The expressions of alpha-fetoprotein, albumin and human cytokeratin 19 mRNA of hepatocyte specific markers were detected with reverse transcription PCR at 7, 14 and 21 days after culture, and periodic acid-Schiff staining was used to identify the functions. RESULTS AND CONCLUSION:Mesenchymal stem cel s could isolated from human umbilical cord successful y, showing fibroblastic morphology and adherent cel characterization. Among these cel s, 96.02%cel s were CD29 positive cel s and 96.6%cel s were CD105 positive cel s. The percentage of CD34 negative cel s was 99.65%. The percentage of CD105+CD29+double positive cel s was 94.84%. The mRNA of alpha-fetoprotein was found on the 7th day after co-cultured with LO2 cel s, and the mRNA of albumin and human cytokeratin 19 were found on the 14th day. After co-cultured for 21 days, the alpha-fetoprotein mRNA could not be observed in the co-culture group. The expressions of albumin and human cytokeratin 19 were increased at 14 days. After co-cultured for 21 days, the glycogen staining was positive. Umbilical cord-derived mesenchymal stem cel s can differentiate into hepatocyte-like cel s after co-cultured with normal hepatocytes.

Objective To investigate the relation between intrauterine growth and the development of carotid atherosclerosis in later life. Methods The intima-media thickness of carotid was measured with ultrasonography in 2036 people aged above fifty who had complete birth records, and divided into normal and abnormal group. They were asked to fill in the cardio-cerebrovascular questionnaire, and venous blood samples were taken and analysed for various biochemical parameters. The relation between carotid atherosclerosis and various parameters at birth and in adult life was assessed. Results The birthweight and head circumference in abnormal group were less than those in normal. The prevalence of carotid atherosclerosis was greatest in those weighed 2500g or less, whose risk of carotid atherosclerosis was greater than those weighed between 3000g and 3500g, after adjustment for cardiovascular risk factors. Conclusions Increased atherogenesis may be one independent mechanism mediating the epidemiological link between impaired fetal growth and vascular disease.

This study examined the incidence, neuropsychological characteristics and risk factors of cognitive impairment 3 months after stroke in China. Five regions that differed in geography and economy in China were selected. Patients from the hospitals located in the five regions were prescreened at admission, and the demographic data, vascular risk factors and clinical characteristics of stroke were obtained. A battery of cognitive-specific domain tests was performed in the patients who failed to pass cognitive screening 3 months post stroke. Patients were diagnosed as having post-stroke cognitive impairment (PSCI) or no cognitive impairment (NCI) based on the results of the neuropsychological tests. Univariate analysis was performed for suspect risk factors, and significant variables were entered in multivariable logistic regression analysis. Our results showed that a total of 633 patients were recruited 3 months after stroke; complete cognitive tests were performed in 577 of the stroke patients. The incidence of PSCI in these Chinese patients was 30.7%. There were 129 (22.4%) patients with visuospatial impairment, 67 (11.6%) with executive impairment, 60 (10.4%) with memory impairment and 18 (3.1%) with attention impairment. The risk factors associated with PSCI were older age (odds ratio [OR] 1.76, 95% confidence interval [CI] 1.20-2.58), low education level (OR 2.45, 95% CI 1.65-3.64), depressive symptom (OR 1.69, 95% CI 1.09-2.61), obesity (OR 2.57, 95% CI 1.41-4.71), stroke severity 3 months post stroke (OR 1.62, 95%CI 1.10-2.37) and cortex lesion (OR 1.55, 95% CI 1.04-2.31). It was concluded that PSCI occurs commonly 3 months after first-ever stroke in Chinese patients. Visuospatial ability may be the most frequently impaired cognitive domain for the patients with stroke. The critical risk factors of PSCI are older age, low education level, depressive symptom, obesity, stroke severity 3 months post stroke and cortex lesion.

OBJECTIVE: To improve the hemocompatibility of decellular vascular matrix via heparin-iron complex multilayers (HICMs) nanomodification. METHODS: A novel thrombo-resistant surface for decellular xenograft was developed by alternating linkage of dihydroxy-iron and heparin to decellular bovine jugular vein (DC-BJV), and its surface characterization, biomechanical stability and hemocompatibility were detected by scanning electron microscopy, tensile test and hemocompatibility evaluation, respectively. RESULTS: A toluidine blue colorimetric method indicated the amount of linked heparin was about (808±86) μg/cm2 per assembly-cycle. Scanning electron microscopic (SEM) images proved that HICMs were uniformly linked to and formed nanoscale films around the fibrils of DC-BJV. Toluidine blue staining histologic images showed that HICMs were linked mainly to DC-BJV surfaces. Washing test showed that the release of heparin was (281±43), (422 ± 60), (729±81), (1053±116), (1317±157), (1618±187) and (1945 ± 268 ) μg/cm(2) at 1 day, 1, 2, 3, 4, 6 and 8 week washing, respectively. Tensile tests showed an increased biomechanical stability. Hemocompatibility evaluations showed that PT and APTT of all the trial groups were above the normal reference ranges and that mean platelet count per 10000 μm2 area was 8±4 for HICMs layer-by-layer modified BJV (LBL-BJV) vs 48±16 for DC-BJV. CONCLUSION HICMs are firmly linked to DC-BJV, and can form nanoscale thrombo-resistant films, which yield a sustained release of heparin. HICMs nanomodification improves the hemocompatibility of decellular xenograft.
Animals ; Biocompatible Materials ; Blood Vessel Prosthesis ; Cattle ; Cell-Free System ; Coated Materials, Biocompatible ; chemical synthesis ; chemistry ; pharmacology ; Heparin ; administration & dosage ; chemistry ; Iron ; administration & dosage ; chemistry ; Jugular Veins ; Nanostructures ; chemistry ; ultrastructure ; Surface Properties ; Tissue Scaffolds ; Transplantation, Heterologous

Objective To measure the concentration of intracellular free Ca2+ ([Ca2+]i) in neuron-like cells resulted from rat bone mesenchymal stem cell (BMSCs) differentiation induced by salvia miltiorrhiza injection and provide some theoretical basis for the BMSCs transplantation. Methods The rat BMSCs were separated from rat bone marrow and cultured in vitro. After induced by basic fibroblast growth factor and 10mL/L salvia miltiorrhiza injection, the cells were identified with immunofluorescence staining against NeuN. The same procedure was performed on primarily cultured hippocampal neurons. Then, the [Ca2+]i of the differentiated neuron-like cells was determined and compared with primarily cultured hippocampal neurons. Results The BMSCs after induced by basic fibroblast growth factor and salvia miltiorrhiza injection expressed neuronal phenotypes similar to the cell appearance of neurons with NeuN. The average fluorescence intensity of the neuron-like cells derived from BMSCs was 984.75±79.51, while the average fluorescence intensity of the primarily cultured hippocampal neurons was 769.42±60.93. No significant difference was found between them (P>0.05). Conclusion The neuron-like cells from rat BMSCs differentiation induced by salvia miltiorrhiza injection possess certain neuronal properties.

Objective To explore the effects of salvia miltiorrhizae (SM) injection on the apoptosis of cultured rat neuronal stem cells induced by hypoxia and the activity of Caspase-3, in order to provide the further evidence for the molecular mechanism of neuroprotection of SM injection. Methods The neuronal stem cells from neonatal rat hippocampus were cultured and divided randomly into normal control group, hypoxia group and SM treatment group. After Hoechst staining, the apoptotic morphological change and apoptosis percentage were observed under fluorescence microscope. The activities of Caspase-3 in the 3 groups were evaluated by the colorimetric assay. Results Compared with normal control group [(2.75±0.28)%, 1.16±0.07], the percentage of apoptosis and the activity of Caspase-3 were increased significantly in neuronal stem cells cultured in hypoxia [(30.12%±2.09)%,3.85±0.41, P<0.05). Application of SM injection reduced markedly the percentage of apoptosis and the activity of Caspase-3 of the neuronal stem cells cultured in hypoxia [(9.16±1.34)%, 1.50±0.09, P<0.05].Conclusion SM injection can depress the apoptosis of the rat neuronal stem cells induced by hypoxia,so as to exert the neuroprotection.

Objective To investigate the expression of vascular endothelial growth factor (VEGF) and aquaporin 4 (AQP4) in giiomas and brain metastases, and explore the role of VEGF and AQP4 in the histopathology and formation of peritumoral edema of primary and metastatic gliomas. Methods Immunohistocbemical method was used to examine the protein expression of VEGF and AQP4 in 73 paraffin-embeded, pathologically confirmed glioma and 15 metastatic tumor specimens collected between 1999 and 2001. Eight normal brain tissue specimens were used as the control. Results VEGF protein was not detected in normal brain tissues. VEGF expression was detected in gliomas and the expression level increased obviously along with the histological grade of the tumor. Significant differences were found in VEGF expression between malignant and low-grade gliomas, between low-grade gliomas and normal brain tissues, and between intracranial metastatic tumors and normal brain tissues and low-grade gliomas (P<0.05), but not between intracranial metastatic tumors and malignant gliomas (P>0.05). AQP4 protein expression was found in all the collected samples, and its expression differed significantly between normal brain tissues and malignant gliomas or intracranial metastatic tumors, and also between low-grade gliomas and malignant gliomas or intracranial metastatic tumors (P<0.05), but not between normal brain tissues and low-grade gliomas or between intracranialmetastatic tumors and malignant gliomas (P>0.05). VEGF protein expression showed a significant positive correlation to AQP4 protein expression (r=0.516, P<0.05). Conclusion As important molecular biological factors, VEGF and AQP4 participate in the formation peritumoral brain edema of gliomas and exhibit a synergie effect in this process.