Objective To investigate the differentiation of bone marrow stromal cells (BMSC) into neuron-like cells and to explore their potential use for neural transplantation. Methods BMSC from rats and adult humans were cultured in serum-containing media. Salvia miltiorrhiza was used to induce human BMSC (hBMSC) to differentiate. BMSC were identified with immunocytochemistry. Semi-quantitative RT-PCR was used to examine mRNA expression of neurofilamentl (NF1), nestin and neuron-specific enolase (NSE) in rat BMSC (rBMSC). Rat BMSC labelled by Hoschst33258 were transplanted into striatum of rats to trace migration and distribution. Results BMSC expressed NSE, NF1 and nestin mRNA, and NF1 mRNA and expression was increased with induction of Salvia miltiorrhiza. A small number of hBMSC were stained by anti-nestin, anti-GFAP and anti-S100. Salvia miltiorrhiza could induce hBMSC to differentiate into neuron-like cells.Some differentiated neuron-like cells, that expressed NSE, beta-tubulin and NF-200, showed typical neuron morphology, but some neuron-like cells also expressed alpha smooth muscle protein, making their neuron identification complicated. rBMSC could migrate and adapted in the host brains after being transplanted. Conclusion Bone marrow stromal cells could express phenotypes of neurons, and Salvia miltiorrhiza could induce hBMSC to differentiate into neuron-like cells. If BMSC could be converted into neurons instead of mesenchymal derivatives, they would be an abundant and accessible cellular source to treat a variety of neurological diseases.
Objective To study the potential risk factors for severe acute respiratory syndromes (SARS)-related deaths in Beijing. Methods Epidemiological data were collected among the confirmed SARS patients officially reported by Beijing Centers for Disease Control and Prevention (BCDC), and information was also supplemented by a follow-up case survey. Chi-square test and multivariate stepwise logistic regression analysis were performed. Results Old age (over 60 years) was found to be significantly associated with SARS-related deaths in the univariate analysis. Also, history of contacting SARS patients within 2 weeks prior to the onset of illness, health occupation, and inferior hospital ranking as well as longer interval of clinic consulting (longer than 1 day) were the risk factors for SARS-related deaths. Multivariate stepwise logistic regression analysis found four risk factors for SARS-related deaths. Conclusion Old age (over 60 years) is the major risk factor for SARS-related deaths.Moreover, hospital health workers, the designated hospitals for SARS clinical services and the interval of consulting doctors (less than 1 day) are protective factors for surviving from SARS.
Objective To study the mechanism of lactose intolerance (LI) by cloning the mouse lactase cDNA and recombining a vector. Methods Total murine RNA was isolated from the small intestine of a 4-week-old BALB/c mouse (♂).Gene-specific primers were designed and synthesized according to the cDNA sequences of lactase-phlorizin hydrolase (LPH) in human, rat, and rabbit. A coding sequence (CDS) fragment was obtained using RT-PCR, and inserted into a clone vector pNEB-193, then the cDNA was sequenced and analyzed using bioinformatics. Results The cDNA from the BALB/c mouse with 912 bp encoding 303 amino acid residues. Analysis of the deduced amino acid sequence using bioinformatics revealed that this cDNA shared extensive sequence homology with human LPH containing a conserved glycosy1 hydrolase family 1 motif important for regulating lactase intolerance. Conclusion BALB/c mouse LPH cDNA (GenBank accession No: AY751548) provides a necessary foundation for study of the biological function and regulatory mechanism of the lactose intolerance in mice.
Objective To characterize the immune reaction in SD rats exposed to trichloroethylene (TCE) and to identify the gene expression profiles involved in skin after TCE exposure. Methods Fifteen percent of TCE was injected intradermally into the rat back (100 μL/120 g) at intervals of 7 days. Whole blood was collected 24 h after the fifth or seventh intradermic administration of TCE. The percentages of CD4+ and CD8+ of T lymphocytes were measured by a flow cytometer. The concentrations of IFN-gamma and IL-4 in the serum were semi-quantified by ELISA. Total RNAs of skin samples at 3 h or 24 h after the seventh dose of TCE in SD rats were extracted, and gene expression profiles of these tissues were analyszed by rat toxicology U34 array of Affymetrix. Results Obvious decline of CD4+ in T lymphocytes was observed in theTCE-administer group. No significant concentration differences in IFN-gamma and IL-4 were found between TCE-treated and control rats. Gadd45a and Mel were significantly up regulated in skin tissue 24 h after TCE exposure. The expression regulation of immune response factors was as active as proteins associated with lipid metabolism and synthesis process in these skin samples of SD rats exposed to TCE. Conclusion T-helper type 1 cells mediate immune response can not be elicited in TCE-treated SD rats, but certain immune disorder can be induced.
Objective To investigate whether overweight and obesity might cause oxidative stress and potential oxidative damage in overweight and obese children, and to explore its possible mechanism. Methods Eighty-five overweight and obese children(OOC), and eighty-five age-matched healthy children (HC) were recruited in this case-control study. The present study analyzed spectrophotometrically vitamin C (VC), vitamin E (VE), and β-carotene (β-CAR) in plasma, as well as the activities of superoxide dismutase (SOD), catalase (CAT), and the level of malondialdehyde (MDA) in erythrocytes. Results Compared with those of VC, VE, β-CAR, SOD, CAT and MDA in the HC group, the average values of VC, VE, β-CAR, SOD, and CAT in the OOC group were significantly decreased (P＜0.001), while the average value of MDA in the OOC group was significantly increased (P＜0.001). The regression analysis demonstrated that VC, VE, β-CAR, SOD, and CAT were negatively correlated (P＜0.05-0.01), and MDA was positively correlated with BMI (P＜0.05). Fitting to the model of multiple stepwise regression of BMI on VC, VE, β-CAR, SOD, CAT, and MDA in 85 OOC was Y = 27.0041 + 0.2541MDA - 2.1448β-CAR - 0.0090CAT, where F =43.8088, P＜0.001, r= 0.7866, r2= 0.6187, adjusted r2= 0.6046. The findings from the reliability analysis for VC, VE, β-CAR, SOD, CAT, and MDA used to reflect increased oxidative stress and potential oxidative damage in the OOC showed that the reliability coefficients (alpha, 6 items) = 0.7231, P＜0.0001, and that the standardized item alpha = 0.9207, P＜0.0001. Conclusion The present study suggests that there exists an increased oxidative stress in overweight and obese children.
Objective To investigate the reduction of chlorination by-products (CBPs) precursors using the fluidized-bed biofilm reactor (FBBR). Methods Reduction of total organic carbon (TOC), ultraviolet absorbance (UV254), trihalomethane (THM)formation potential (THMFP), haloacetic acid (HAA) formation potential (HAAFP), and ammonia in FBBR were evaluated in detail. Results The reduction of TOC or UV254 was low, on average 12.6% and 4.7%, respectively, while the reduction of THMFP and HAAFP was significant. The reduction of ammonia was 30%-40% even below 3℃, however, it could quickly rise to over 50% above 3℃. Conclusions The FBBR effectively reduces CBPs and ammonia in drinking water even at low temperature and seems to be a very promising and competitive drinking water reactor for polluted surface source waters, especially in China.
Objective To screen the antimalarial compounds of daphnetin derivatives against Plasmodium falciparum in vitro. Method Plasmodium faciparum (FCC1) was cultured in vitro by a modified method of Trager and Jensen. Antimalarial compounds were screened by microscopy-based assay and microfluorimetric method. Results DA79 and DA78 showed potent antimalarial activity against Plasmodium falciparum cultured in vitro. Conclusion Though the relationship between the structures of daphnetin derivatives and their antimalarial activities has not been clarified yet, this study may provide a new direction for discovery of more potential antimalarial compounds.
Objective To analyze the structure of bacteria in drinking water by molecular biological techniques. Methods DNA of bacteria in drinking water was directly extracted without culture. 16S ribosomal DNA fragments, including V-6, -7, and -8regions, were amplified with universal primers (EUBf933GC and EUBr1387) and analyzed by DGGE. Results DGGE indicated that amplification products could be separated. The results showed that DGGE could be used in the separation of different microbial 16SrRNA genes extracted from drinking water. Though there were special bacteria in different water samples, the predominant bacteria were essentially the same. Three sequences of the reclaimed specific bands were obtained, and phylogenetic tree of these bands was made. Conclusion Bacterial diversity in drinking water is identified by molecular biological techniques.
Objective To study the combined effect of fluoride and arsenate on the expression of SD rat osteoblastic osteoclast differentiation factor (ODF) mRNA and osteoprotegerin (OPG) mRNA. Methods Osteoblasts were obtained by enzymatic isolation from newborn SD rats. A factorial experiment was performed. Osteoblasts were exposed to NaF (0.5 mmolF/L, 4 molF/L) and Na3AsH2(12.5 μmolAs/L and 200 μmolAs/L) separately or F plus As and cultured for 48 h. The gene expression of osteoblastic ODF and OPG was observed by RT-PCR. Results The expression of ODF mRNA increased in F0.5, F4 groups compared with control group and two groups of F0.5As200, F4As200 compared with As200 group, and decreased significantly in groups of F4As125, F0.5As200, and F4As200. The expression of OPG mRNA decreased in groups of F4, As200, F4As12.5, F0.5As200, and F4As200. Conclusion The joint effect of fluoride and arsenate on the gene expression of ODF is antagonistic, while the combined effect on the gene expression of OPG is synergistic. F4, F4As12.5, and F0.5As200 promote bone resorption of rat osteoclasts, whereas F0.5As12.5 inhibits osteolytic effect of rat osteoclasts.
Objective To investigate the current status of disabled children and prevalence of disabilities in children aged 0-6 years and their risk factors, and to provide scientific evidence for making relevant policies for disabled children. Methods In a community-based cross-sectional study, multi-phase, stratified, unequal proportional and cluster sampling was adopted to survey 60 124 children aged 0-6 years. All the investigated children were screened for disabilities, and those with positive screening tests were further diagnosed by various specialties. Results A total of 819 children were diagnosed as disabled with an overall prevalence of 1.362%, 0.155% for hearing disability, 0.160% for visual disability, 0.931% for intelligent disability, 0.424% for limb disability, and 0.101% for mental disability. Prevalence of disability in children was higher in rural areas, and in families with two or more children, low educational level or in divorced families. Conclusion The prevalence of disability can be reduced by economic development, improvement of health care and quality of population, as well as harmonious familial relationship, early prevention of disability, and preschool education for disabled children.
Objective To find out the mechanisms of redifferentiation and reversion of malignant human gastric cancer cells induced by ascorbic acid. Methods Human gastric cancer cells grown in the laboratory were used. The Trypan blue dye exclusion method was used to determine the cell doubling time. The electrophoresis rate and colonogenic potential were the indices used to measure the rate of redifferentiation. The content of malondialdehyde (MDA) was measured using the thiobarbituric acid(TBA) method. The activities of superoxide dismutase (SOD), catalase (CAT) and the content of H2O2 were evaluated by spectrophotography. Results Six mmol/L ascorbic acid was used as a positive control. Human gastric cancer cells were treated with 75 μm hydrogen peroxide, which alleviated many of the malignant characteristics. For example, the cell surface charge obviously decreased and the electrophoresis rate dropped from 2.21 to 1.10 μm·s-1·V-1·cm-1. The colonogenic potential, a measure of cell differentiation, decreased 90.2%. After treatment with ascorbic acid, there was a concentration- and time-dependent increase in hydrogen peroxide (H2O2) and the activity of superoxide dismutase (SOD). However, the activity of catalase (CAT) resulted in a concentration- and time-dependent decrease. SOD and 3-amino-1,2,4-triazole (AT) exhibited some effects, but there were statistically significant differences between the SOD and AT group and the H2O2 group. Conclusions Ascorbic acid induces growth inhibition and redifferentiation of human gastric cancer cells through the production of hydrogen peroxide.
Objective To analyze the molecular colning of a fragile site-associated gene. Methods Genomic Chinese hamster ovary (CHO) DNA library was constructed using high molecular weight CHO DNA partially digested with MboI restriction enzyme from cultured CHO cells. Screening of genomic DNA library followed the established procedures. Genomic CHO in the positive clones was sequenced. Appropriate primers were designed for the reverse transcriptase-polymerase chain reactions (RT-PCR). The RT-PCR products were cloned into a pCRⅡ TOPO vector and confirmed by DNA sequencing. Antibodies were prepared using synthetic peptides as antigens by immunizing the rabbits. Immunohistochemical analyses were performed to evaluate the expression of the novel gene in different tissues. Results To investigate the molecular mechanism underlying the initial events of mdrla amplification, we cloned 1q31 fragile site DNA. Strikingly, we found that this fragile site contained a novel gene which was designated as a fragile site-associated (FSA) gene. FSA encoded an unusually large mRNA of ～16 kb. Full-length human FSA cDNA was cloned. FSA mRNA was expressed in many cultured cells and tissue types. Immunohistochemical analyses also revealed an expression pattern of the encoded proteins in postmitotic, well-differentiated epithelial compartments of many organs, including colon, mammary glands, ovary, prostate, and bladder. Conclusion FSA plays an important role in regulating mammalian epithelial cell growth and differentiation.
Objective To observe the effects of iron and phosphorus on Microcystis physiological reactions. Methods The experimental conditions were chosen as the light dark cycles of 16 h 8 h, 12 h 12 h, and 8 h 16 h. The cell change of morphology and life history, cell number, cell color, and cell area of Microcystis were analyzed quantitatively. According to the resource competition and Monod equation, Microcystis kinetics of phosphorus and iron were also examined. Results The longer light time caused more special cell division, slower growth rate, and easier change of bigger cell area. The color of alga was changed from green to brown. Ks and μmax of phosphorus absorption were 0.0352 μ mol·L-1and 0.493 d-1, respectively. Those of iron absorption were 0.00323 μmol·L-1and 0.483 d-1. Conclusion Microcystis bloom is more dominant than other algae.
Objective To predict the impact of MF radiation on human health.Methods The vertical distribution of field intensity was estimated by analogism on the basis of measured values from simulation measurement. Results A kind of analogism on the basis of geometric proportion decay pattern is put forward in the essay. It showed that with increasing of height the field intensity increased according to geometric proportion law. Conclusion This geometric proportion prediction model can be used to estimate the impact of MF radiation on inhabited environment, and can act as a reference pattern in predicting the environmental impact level of MF radiation.