Objective To understand the prevalence,consequences and risk factors of falls among urban community-dwelling elderly in Beijing. Methods A cross-sectional study was conducted in Longtan Community,Beijing.A total of 1512 individuals aged 60 years or over were selected by stratified cluster sampling.Data regarding the frequency of falls in the previous year,as well as circumstances,consequence and related factors of falls were collected from the elderly through face-to-face interviews with questionnaires in their home. Results The prevalence of falls was 18.0% on the average among 1512 participants,higher in women (20.1%) than in men (14.9%) (P=0.006),and increased with age (X2 for trend=10.37,P=0.001).The total rate of falls-induced injuries among the fallers was 37.7%.Falls usually resulted in soft-tissues bruises (58.7%),fear of repeated episodes of falls (58.8%),loss of independence and confidence in movement (35.7%) and even in hip fracture.In addition to the burden of medical care,falls also generated a big economic burden.Occurrence of falls was significantly associated with both intrinsic and extrinsic factors.The related factors of falls in the elderly included age≥60-70 years,femininity,less physical activities,fear of future falls,living alone,severely impaired vision,health problem-impacted activities of daily living,chronic diseases (diabetes,hypertension,postural hypotension,stroke sequela,cataract,arthritis,dementia and depression),medications (psychoactive,anti-diabetic),gait imbalance,high bed and faintly-lighted stairway.Conclusion The prevalence of falls among urban community-dwelling elderly in Beijing is closely associated with significant associated with intrinsic and extrinsic factors.Efforts to prevent fails in the elderly should be made at community level.
Objective To detect cadmium in environmental and food samples by graphite furnace atomic absorption spectroscopy (GFAAS) and inductively coupled plasma atomic emission spectroscopy (ICPAES). Methods An indirect competitive enzyme-linked immunosorbent assay (IC-ELISA) was developed based on a cadmium-specific monoclonal antibody.IC-ELISA for cadmium in environmental and food samples was evaluated. Results IC-ELISA showed an IC50 of 45.6 μg/L with a detection limit of 1.95 μg/L for cadmium,and showed a mean recovery ranging 97.67%-107.08%.The coefficient of variations for intra- and iuterassay was 3.41%-6.61% and 4.70%-9.21%,respectively.The correlation coefficient between IC-ELISA and GFAAS was 0.998. Conclusion IC-ELISA can detect and quantify cadmium residue in environmental or food samples.
Objective To assess the effectiveness of complementary food supplements with protein and multi-micronutrients on hemoglobin and anemia in infants and young children. Methods In 5 poor counties of Gansu,984 children aged 6-12 months were enrolled and divided into two groups.In addition to the usual home-made complementary food,all the children were fed one sachet of either Formula i or Formula II supplements each day.Protein and micronutrients were provided in Formula I,while the same energy intake was secured in Formula II as in Formula I.A massive dose of vitamin A was supplemented to all the children every 6 months.Hemoglobin test was done at the same time. Results Prevalence of anemia was about 35% in both Formula I and Formula II group at baseline,and there were no differences in hemoglobin concentration between the two groups.During the 6-month and 12-month supplementation,hemoglobin of children in Formula I group was higher than that in Formula II group (P＜0.05),and hemoglobin increase in Formula 1 group was significantly higher than that in Formula II group (P＜0.001).After 6- and 12-month supplementation,the prevalence of anemia in Formula I group dropped to 19.1% and 8.2% respectively,and it was 28.0% and 12.4% in Formula 2 group.The prevalence of anemia in Formula I group was significantly lower than that in Formula II group (P＜0.05).After adjusting age and hemoglobin level at baseline,the hemoglobin increase at age of 24 months in formula 1 group was higher (10.7 g/L vs 7.9 g/L,P＜0.0001). Conclusion Micronutrient fortified complementary food supplements,with large-dose vitamin A,is effective for children aged 6-12 months in terms of iron deficiency prevention.
Objective To investigate the struvite precipitation under constant and non-constant pH conditions and to test a stainless steel device under different operating regimes to maximize the recovery of struvite. Methods The molar ratio of NH4+:Mg2+:PO43- was adjusted to 1:1.2:1.2 and pH was elevated to 9.0.The absorbance measurement was used to trace the process of struvite crystallization.Wastewater and precipitate analysis was done by standard analytical methods. Results The pH constant experiment reported a significantly higher struvite precipitation (24.6±0.86 g) than the non-constant pH experiment (19.8±1.86 g).The SAR ranged from 5.6 to 8.2 g m-2h-1 to 3.6-4.8 g m-2h-1 in pH constant and non-constant experiments,respectively.The highest struvite deposit on the device was found in regime 3 followed by in regimes 2 and 4.The highest PO43-(97.2%) and NH4+ (71%) removal was reported in the Ri regime.None of the influent Cu2+ or Zn2+ was precipitated on the device. Conclusion A higher struvite yield is evident in pH constant experiments.Moreover,the stainless steel device facilitates the isolation of heavy metal free pure (around 96%) struvite from swine waste biogas digester effluent contaminated with cu2+ and Zn2+ and the highest yield is attainable with the device operating at 50 rpm with agitation by a magnetic stirrer.
Objective To investigate the potential impact of ambient air pollution on public health under various traffic policies in Shanghai. Methods The exposure level of Shanghai residents to air pollution under various planned traffic scenarios was estimated,and the public health impact was assessed using concentration-response functions derived from available epidemiological studies. Results Our results showed that ambient air pollution in relation to traffic scenarios had a significant impact on the future health status of Shanghai residents.Compared with the base case scenario,implementation of various traffic scenarios could prevent 759-1574,1885-2420,and 2277-2650 PM10-related avoidable deaths (mean-value) in 2010,2015,and 2020,respectively.It could also decrease the incidence of several relevant diseases. Conclusion Our findings emphasize the need to consider air pollution-related health effects as an important impact of traffic policy in Shanghai.
Objective To evaluate the toxic and carcinogenic potential of ozone alone or in combination with 4-(N-methyl-N-nitrosamino)-1-(3-pyddyl)-1-butanone (NNK) and/or dibutyl phthalate (DBP). Methods Male and female B6C3F1 mice were exposed,through inhalation,intravenous administration and diet,to 0.5 ppm of ozone,1.0 mg/kg of NNK and 5000 ppm of DBP,individually and in combination for 16 and 32 weeks. Results No treatment-related death was seen,but significant differences in body and organ weights between control and treated mice were observed during the study.No incidence of lung tumor incidence was recorded in mice exposed to either ozone alone or combined treatment.Oviductal carcinomas were observed in female mice exposed to ozone or DBP alone for 16 weeks and ozone in combination with NNK and DBP for 32 weeks. Conclusion Although ozone alone and in conjunction with NNK and/or DBP does not induce lung cancer under our experimental conditions,they induce oviductal carcinomas in B6C3F1 mice.
Objective To investigate the oxidative damage to lung tissue and peripherial blood in PM2.5-treated rats.Methods PM2.5 samples were collected using an auto-sampling instrument in summer and winter.Treated samples were endotracheally instilled into rats.Activity of reduced glutathione peroxidase (GSH-Px) and concentration of malondialdehyde (MDA) were used as oxidative damage biomarkers of lung tissue and peripheral blood detected with the biochemical method.DNA migration length (μm) and rate of tail were used as DNA damage biomarkers of lung tissue and peripheral blood detected with the biochemical method. Results The activity of GSH-Px and the concentration of MDA in lung tissue significantly decreased after exposure to PM2.5 for 7-14 days.In peripheral blood,the concentration of MDA decreased,but the activity of GSH-Px increased 7 and 14 days after experiments.The two indicators had a dose-effect relation and similar changing tendency in lung tissue and peripheral blood.The DNA migration length (μm) and rate of tail in lung tissue and peripheral blood significantly increased 7 and 14 days after exposure to PM2.5.The two indicators had a dose-effect relation and similar changing tendency in lung tissue and peripheral blood. Conclusion PM2.5 has a definite oxidative effect on lung tissue and peripheral blood.The activity of GSH-Px and the concentration of MDA are valuable biomarkers of oxidative lung tissue damage induced by PM2.5.The DNA migration length (μm) and rate of tail are simple and valuable biomarkers of PM2.5-induced DNA damage in lung tissues and peripheral blood.The degree of DNA damage in peripheral blood can predict the degree of DNA damage in lung tissue.
Objective To understand the molecular basis for a potential reaction mechanism and develop novel antibiotics with homology modeling for 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) synthase (HMGS). Methods The genetic engineering technology and the composer module of SYBYL7.0 program were used,while the HMGS three-dimensional structure was analyzed by homology modeling. Results The mvaS gene was cloned from Streptococcus pneumoniae and overexpressed in Escherichia coli from a pET28 vector.The expressed enzyme (about 46 kDa) was purified by affinity chromatography with a specific activity of 3.24 μmol/min/mg.Optimal conditions were pH 9.75 and 10 mmol/L MgCl2 at 37℃.The Vmax and Km were 4.69 μmol/mirdmg and 213 μmol/L respectively.The 3D model of S.pneumoniae HMGS was established based on structure template of HMGS of Enterococcus faecalis. Conclusion The structure of HMGS will facilitate the structure-based design of alternative drugs to cholesterol-lowering therapies or to novel antibiotics to the Gram-positive cocci,whereas the recombinant HMGS will prove useful for drug development against a different enzyme in the mevalonate pathway.
Objective To prepare artificial antigens and anti-citrinin egg yolk-derived immunoglobulin (IgY) to build an enzyme-linked immunosorbent assay (ELISA) for citrinin (CTN). Methods CTN was conjugated with bovine serum albumin (BSA),ovalbumin (OVA) with formaldehyde condensation method to prepare artificial antigens and identified by ultraviolet (UV) spectrometry and Infrared (IR) spectrometry.Artificial antigens for CTN and anti-CTN IgY were purified with polyethylene glycol two-step precipitation method and identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE).ELISA with IgY was established.Cross-reactivity of lgY with various structural similarities to CTN and possible co-occurrence with CTN in agricultural commodities were studied. Results UV and IR absorption spectra suggested that CTN was correlated with the carrier protein of BSA or OVA.SDS-PAGE patterns showed that the anti-CTN IgY was almost pure with a molecular weight of approximate 100 KD.The indirect competitive ELISA showed that the detection limit of CTN synthesized.The established ELISA can be used to determine CTN- contaminated samples.
Objective Lidamycin,an enediyne antibiotic,leads to apoptosis and mitotic cell death of human tumor cells at high and low concentrations.The reason why tumor cells have distinct responses to lidamycin remains elusive.This study was to elucidate if cellular prosurvival molecules are involved in these responses. Methods Cleavage of chromatin and DNA was observed by chromatin condensation and agarose gel electrophoresis.Accumulation of rhodamine 123 in lidamycin-treated cells was assayed by flow cytometry.Cell multinucleation was detected by staining with Hoechst 33342.Western blot and senescence-associated β-galactosidase (SA-β-gal) staining were used to analyze protein expression and senescence-like phenotype,respectively. Results SIRTI deacetylase remained unchanged in 0.5 nmol/L lidamycin whereas cleavage occurred when apoptosis was induced by lidamycin.Increased FOXO3a,SOD-1 and SOD-2 expression and transient phosphorylation of ERK were detected after exposure of human hepatoma BEL-7402 cells to 0.5 nmol/L lidamycin.High expressions of SIRT1 and Akt were found in colon carcinoma HCT116 p53 knock-out cells exposed to lidamycin.Degradation of PARP and p53 by lidamycin as a substitute for SIRT1 and Akt was confirmed with caspase inhibitor Q-VD-OPh and proteasome inhibitor MG132. Resistance to lidamycin-induced DNA cleavage was observed in breast cancer doxorubicin-resistant MCF-7 cells.This was not induced by P-glycoprotein as no accumulation of rhodamine 123 was detected in the resistant cells following exposure to lidamycin.In contrast to sensitive MCF-7 cells,a lower multinucleation rate for the resistant cells was measured following exposure to equal concentrations of lidamycin. Conclusions Cellular prosurvival molecules,such as SIRT1,Akt,SOD-1,SOD-2 and other unknown factors can influence the action of lidamycin on human tumor cells.
Objective To detect the specific mutations in rpoB gene of Mycobacterium tuberculosis by oligonucleotide microarray.Methods Four wild-type and 8 mutant probes were used to detect rifampin resistant strains.Target DNA of M.tuberculosis was amplified by PCR,hybridized and scanned.Direct sequencing was performed to verify the results of oligonuclcotide microarray.Results of the 102 rifampin-resistant strains 98 (96.1%) had mutations in the rpoB genes. Conclusion Oligonucleotide microarray with mutation-specific probes is a reliable and useful tool for the rapid and accurate diagnosis of rifampin resistance in M.tuberculosis isolates.
Objective To investigate the subchronic toxicity of soy isoflavones (SIF) in male rats. Method Fifty Sprague-Dawley rats were randomly divided into 5 groups,10 rats per group.SIF were given to rats in different groups by gavage at dose of 0,0.2,0.5,1.5,and 4.5 g/kg bw,respectively for 13 weeks.Clinical manifestations,body weight,and food consumption were observed weekly.At the end of the study,urinalysis,hematology,clinical chemistry,total testosterone,and follicle-stimulating hormone were tested,and histopathological examinations were performed. Results No mortality,ophthalmic abnormalities or treatment-related clinical signs were identified during the study.As compared with the control group,significantly lower body weights and food consumption were observed in 1.5 and 4.5 g/kg bw groups.In clinical chemistry tests,triglyceride was significantly decreased and high-density lipoprotein cholesterol was significantly increased in all SIF-treated groups.Total testosterone levels were significantly lower in 0.50,1.50,and 4.5 g/kg bw dose groups than in the control group.Microscopic examination showed that the mammary glands exhibited hyperplasia and excreted latex in rats of the 4.5 g/kg bw group.No changes attributable to treatment of SIF in other parameters were found. Conclusion SIF at high dosages caused significant endocrine disruption in male rats.The no observed adverse effect level (NOAEL) of SIF to male rats in this study is considered to be 0.20 g/kg bw.
Objective To observe the effect of electromagnetic pulse (EMP) exposure on cerebral micro vascular permeability in rats.Methods The whole-body of male Sprague-Dawley rats were exposed or sham exposed to 200 pulses or 400 pulses (1 Hz) of EMP at 200 kV/m.At 0.5,1,3,6,and 12 h after EMP exposure,the permeability of cerebral micro vascular was detected by transmission electron microscopy and immunohistochemistry using lanthanum nitrate and endogenous albumin as vascular tracers,respectively. Results The lanthanum nitrate tracer was limited to the micro vascular lumen with no lanthanum nitrate or albumin tracer extravasation in control rat brain.After EMP exposure,the lanthanum nitrate ions reached the tight junction,basal lamina and pericapillary tissue.Similarly,the albumin immunopositive staining was identified in pericapillary tissue.The changes in brain micro vascular permeability were transient,the leakage of micro vascular vessels appeared at 1 h,and reached its peak at 3 h,and nearly recovered at 12 h,after EMP exposure.In addition,the leakage of micro vascular was more obvious after exposure of EMP at 400 pulses than after exposure of EMP at 200 pulses. Conclusion Exposure to 200 and 400 pulses (1 Hz) of EMP at 200 kV/m can increase cerebral micro vascular permeability in rats,which is recoverable.