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1.
Zhonghua Jie He He Hu Xi Za Zhi ; 47(5): 450-454, 2024 May 12.
Artigo em Chinês | MEDLINE | ID: mdl-38706067

RESUMO

Reperfusion is considered as the cornerstone of the treatment of high-risk pulmonary embolism (PE). However, when thrombolysis is contraindicated and surgery or interventional therapy is not available, the treatment of high-risk PE becomes very difficult. To our knowledge, there are no reports of successful treatment of high-risk PE with low-dose anticoagulation. On November 30, 2021, a 56-year-old male patient with subarachnoid hemorrhage was admitted to the emergency department of the First Affiliated Hospital of Chongqing Medical University. On the second day of admission, the patient suddenly went into shock during aneurysm clipping. After implementing D-dimer, markers of myocardial injury, echocardiography and computed tomography pulmonary angiography, a high-risk PE was diagnosed. Due to the contraindication of thrombolysis and the refusal of endovascular treatment, he was eventually cured with low-dose anticoagulation combined with vasopressors.


Assuntos
Anticoagulantes , Embolia Pulmonar , Humanos , Embolia Pulmonar/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Anticoagulantes/administração & dosagem , Anticoagulantes/uso terapêutico , Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Angiografia por Tomografia Computadorizada , Hemorragia Subaracnóidea
2.
Zhonghua Liu Xing Bing Xue Za Zhi ; 40(10): 1314-1323, 2019 Oct 10.
Artigo em Chinês | MEDLINE | ID: mdl-31658537

RESUMO

Epidemiology is a branch of science that mainly involves in the etiology studies of non-randomness phenomenon among homogenous populations. In this paper, we use causal-thinking, supported by its tool-Directed Acyclic Graphs, to illustrate how the estimation of effects is affected by the issues as relations between effect and association, time sequences between variables and their measured counterparts, natural picture of dynamic population, formation of susceptible population, selection of study population, impact of covariates and types of cases etc., on the estimation of effects. This type of thinking may help us to re-capture the epidemiological theories, methods and related applications. Thus, causal-thinking should be strengthened.


Assuntos
Causalidade , Métodos Epidemiológicos , Estatística como Assunto
3.
Zhonghua Gan Zang Bing Za Zhi ; 26(7): 489-494, 2018 Jul 20.
Artigo em Chinês | MEDLINE | ID: mdl-30317769

RESUMO

Objective: To construct the mmu-miR-155 eukaryotic overexpression vector pmR-155 and to investigate its effect on HBV replication and expression of PTEN in vivo. Methods: The mmu-mir-146a precursor gene fragment pre-mmu-mir-146a was amplified by PCR, then connected to the pmR-mCherry plasmid vector after double enzyme digestion, the accuracy of recombinant vector was verified by colony PCR、double enzyme digestion and sequencing; then the recombinant vector was transfected HBV transgene mice(Experimental Group)with hydrodynamics-based injection via vena caudalis, and pmR-mCherry plasmid、PBS were respectively transfected into the mice as Empty plasmid Group、Blank Group. The concentration of IFN-γ in the serum was detected by ELISA. The expression of SOCS1、PTEN mRNA in the liver was detected by qPCR at 30d post-transfectioned. The Western blot was performed to detect the changes in SOCS1、PTEN、HBX in the liver tissue at 30 d post-transfectioned. The results were analyzed with Student's t-test, or one-way analysis of variance and the least significant difference test. Results: the colony PCR、double enzyme digestion and sequencing verified that the gene was inserted into the pmR-mCherry vector. Compared with Blank Group, the expression of miR-155 in the Experimental Group was significantly increased(t = 8.90, P < 0.01); the concentration of IFN-γ in the Experimental Group was significantly increased(F = 26.58, P < 0.01); the mRNA(F(SOCS1 mRNA) = 19.72, P < 0.01; F(PTEN mRNA) = 7.38, P < 0.05) and protein(F(SOCS1) = 50.30, P < 0.01; F(PTEN) = 129.00, P < 0.01) expression of COCS1、PTEN was significantly decreased in the Experimental group and the protein of HBX was also significantly(F(HBX) = 77.97, P < 0.01). Conclusion: The pmR-155 eukaryotic overexpression vector is successfully constructed, this recombinant vector can express miR-155 stably; miR-155 can down-regulate cocs1、PTEN gene expression and up-regulate the expression of IFN-γ, it can inhibit the replication of HBV and a potential targets to treating hepatocellular carcinoma.


Assuntos
Carcinoma Hepatocelular , Replicação do DNA/genética , Vírus da Hepatite B/genética , MicroRNAs/metabolismo , RNA Mensageiro/genética , Animais , Neoplasias Hepáticas , Camundongos , MicroRNAs/genética , PTEN Fosfo-Hidrolase
4.
Zhonghua Liu Xing Bing Xue Za Zhi ; 39(7): 999-1002, 2018 Jul 10.
Artigo em Chinês | MEDLINE | ID: mdl-30060319

RESUMO

Confounding affects the causal relation among the population. Depending on whether the confounders are known, measurable or measured, they can be divided into four categories. Based on Directed Acyclic Graphs, the strategies for confounding control can be classified as (1) the broken-confounding-path method, which can be further divided into single and dual broken paths, corresponding to exposure complete intervention, restriction and stratification, (2) and the reserved-confounding-path method, which can be further divided into incomplete exposure intervention (in instrumental variable design and non-perfect random control test), mediator method and matching method. Among them, random control test, instrumental variable design or Mendelian randomized design, mediator method can meet the requirements for controlling all four types of confounders, while the restriction, stratification and matching methods are only applicable to known, measurable and measured confounders. Identifying the mechanisms of confounding control is a prerequisite for obtaining correct causal effect estimates, which will be helpful in research design.


Assuntos
Causalidade , Fatores de Confusão Epidemiológicos , Distribuição Aleatória , Projetos de Pesquisa , Humanos , Modelos Estatísticos , Ensaios Clínicos Controlados Aleatórios como Assunto
5.
Zhonghua Liu Xing Bing Xue Za Zhi ; 39(6): 770-775, 2018 Jun 10.
Artigo em Chinês | MEDLINE | ID: mdl-29936745

RESUMO

Objective: To investigate the association between maternal pre-pregnant body mass index and gestational weight gain, as well as their interaction on neonatal birthweight. Methods: We built a cohort in Anqing Municipal Hospital from January 2014 to March 2015, enrolling pregnant women who decided to give birth in this hospital. All women were asked to fill a questionnaire for basic information collection. Medical information of both pregnant women and their newborns were obtained through electronic medical record. Chi-square analysis, multinomial logistic regression, multiplicative and additive interaction methods were used to analyze the association between pre-pregnant body mass index and gestational weight gain as well as their interactions on birth weight of the neonates. Results: A total of 2 881 pregnant women were included in this study. Of the 2 881 newborns, 359 (12.46%) were small for gestational age (SGA) and 273 (9.48%) were large for gestational age (LGA). After adjusting the possible confounding factors, results from the multinomial logistic regression showed that pre-pregnancy underweight women were more possible to deliver SGA (aRR=1.33, 95%CI: 1.02-1.73). If the gestational weight gain was below the recommended criteria, the risk of SGA (aRR=1.64, 95%CI: 1.23-2.19) might increase. Pre-pregnancy overweight/obese could increase the risk of being LGA (aRR=1.86, 95%CI: 1.33-2.60). Maternal gestational weight gain above the recommendation level was associated with higher rates of LGA (aRR=2.03, 95%CI: 1.49-2.78). Results from the interaction analysis showed that there appeared no significant interaction between pre-pregnancy BMI and gestational weight on birthweight. Conclusion: Pre-pregnancy body mass index and gestational weight gain were independently associated with neonatal birthweight while pre-pregnancy BMI and gestational weight gain did not present interaction on birthweight.


Assuntos
Peso ao Nascer , Índice de Massa Corporal , Peso Corporal , Gestantes , Aumento de Peso , China/epidemiologia , Estudos de Coortes , Feminino , Ganho de Peso na Gestação , Humanos , Recém-Nascido , Recém-Nascido Pequeno para a Idade Gestacional , Modelos Logísticos , Obesidade/epidemiologia , Sobrepeso/epidemiologia , Gravidez , Complicações na Gravidez , Fatores de Risco , Magreza/epidemiologia
6.
Zhonghua Liu Xing Bing Xue Za Zhi ; 39(6): 858-861, 2018 Jun 10.
Artigo em Chinês | MEDLINE | ID: mdl-29936761

RESUMO

One of the commonly accepted merits of cohort studies (CSs) refers to the exposure precedes outcome superior to other observational designs. We use Directed Acyclic Graphs to construct a causal graph among research populations under CSs. We notice that the substitution of research population in place of a susceptible one can be used for effect estimation. Its correctness depends on the outcome-free status of the substituted population and the performance of both screening and diagnosis regarding the outcomes under study at baseline. The temporal precedence of exposure over outcome occurs theoretically, despite the opposite happens in realities. Correct effect estimate is affected by both the suitability of population substitution and the validities of outcome identification and exclusion.


Assuntos
Estudos de Coortes , Programas de Rastreamento , Projetos de Pesquisa , Causalidade , Fatores de Confusão Epidemiológicos , Métodos Epidemiológicos
7.
Pharmazie ; 71(10): 575-582, 2016 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29441925

RESUMO

OBJECTIVE: This study was performed to evaluate the regulating effects of acetylpuerarin on inflammation in an Alzheimer's disease (AD) rat model and an inflammatory cell model. METHODS: Healthy female Wistar rats and mouse BV2 microglia cells were selected. AD rat models were established with the method of bilateral intrahippocampal amyloid-ß(Aß)1-42 injections and the inflammatory cell models were established using Aß25-35-induced mouse BV2 microglia cells. The cytotoxicity of acetylpuerarin on BV2 microglial cells was detected by MTT assay and the morphological changes of BV2 microglia cells were observed under inverted phase contrast microscope. As inflammatory parameters, the expressions of IL-1ß, iNOS, IL-6 and TNF-α were examined by Elisa, Immunohistochemistry, Quantitative real-time PCR (qRT-PCR), Western blot and Immunofluorescence analyses. We also examined the acetylpuerarin's effect on the activity of PKC-δ, IKKß and caspase-8/caspase-3 pathway. RESULTS: Acetylpuerarin exerted no significant cytotoxicity on BV2 microglia cells and was applied in all subsequent experiments. Acetylpuerarin treatment mitigated Aß25-35-induced morphological changes associated with microglia activation. Moreover, the expressions of caspase-8, cleaved caspase-3, PKC-δ, IKKß, iNOS, IL-1ß and TNF-α in Aß25-35-stimulated BV2 microglia cells were significantly suppressed by acetylpuerarin and in a dose-dependent manner. Additionally, the expression of IL-1ß in hippocampus and the level of IL-6 in serum of Aß1-42 treated rat were reduced by acetylpuerarin and in a concentration-dependent manner. CONCLUSION: Our results suggest that acetylpuerarin's anti-inflammation mechanism on AD may be mediated through the PKC-δ-dependent caspase signalling pathway.


Assuntos
Caspases/efeitos dos fármacos , Encefalite/tratamento farmacológico , Isoflavonas/farmacologia , Proteína Quinase C-delta/efeitos dos fármacos , Doença de Alzheimer/induzido quimicamente , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides , Animais , Sobrevivência Celular/efeitos dos fármacos , Citocinas/metabolismo , Encefalite/induzido quimicamente , Feminino , Ativação de Macrófagos/efeitos dos fármacos , Camundongos , Microglia/efeitos dos fármacos , Fragmentos de Peptídeos , Ratos , Ratos Wistar , Transdução de Sinais/efeitos dos fármacos
8.
Minerva Cardioangiol ; 64(2): 114-20, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25501978

RESUMO

BACKGROUND: The aim of this paper was to investigate the association between the connexin 37 (CX37) 1019C/T polymorphism and susceptibility to dilated cardiomyopathy (DCM). METHODS: Han Chinese diagnosed with DCM between 2005 and 2013 were studied, and they were compared with a control group of 816 persons without DCM from a patient cohort from the Provincial Hospital Affiliated to Anhui Medical University, China. A total of 873 patients with DCM were included. All study and control cases were genotyped by DNA sequencing. RESULTS: Polymorphism C1019T on the Connexin37 gene (CX37) was found in the whole population. The distribution of three genotype frequencies in both groups was in accordance with Hardy-Weinberg equilibrium. The frequency of the CX37 C allele was higher in DCM patients (57.33% vs. 42.03%, P<0.01) compared to the control group. The frequency of C carriers (CC+TC) was 80.41% in DCM patients, compared to 66.7% in controls (P<0.01). DCM risk was significantly increased in carriers of the C allele (CC+TC) than in TT homozygotes (odds ratio [OR]=2.05, 95% confidence interval [CI]: 1.65-2.56). Subsequent stratified analyses demonstrate that a significant difference exists in the frequency of C carriers between male DCM patients and controls (77.61% vs. 69.04%, P<0.01) and in female DCM patients and controls (85.62 % vs. 62.19%, P<0.01). Carriers of the C allele had higher DCM risk compared with TT homozygotes with sex differences (male: OR=1.64, 95% CI: 1.39-1.95; female: OR=2.32, 95% CI: 1.84-2.94). CONCLUSIONS: The C allele in the CX37 gene might be associated with susceptibility to DCM in Chinese Han. Female carriers of the C allele had higher DCM risk compared with TT homozygotes than males.


Assuntos
Povo Asiático/genética , Cardiomiopatia Dilatada/genética , Conexinas/genética , Predisposição Genética para Doença , Idoso , Alelos , Estudos de Casos e Controles , China , Feminino , Frequência do Gene , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA , Fatores Sexuais , Proteína alfa-4 de Junções Comunicantes
9.
Indian J Pharm Sci ; 76(3): 235-9, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-25035536

RESUMO

Water, methanol and ethanol extracts of Evodia rutaecarpa were tested for antinociceptive activity, which were correlated with the contents of evodiamine, rutaecarpine and evodine. Determination of contents was achieved by chromatographic techniques. Extracts were evaluated for antinociceptive activities using hot-plate test; acetic acid-induced writhing test and formalin test. All three extracts of Evodia rutaecarpa showed antinociceptive activities but the ethanol extract exhibited better effect. The better antinociceptive activity appeared to be related to higher contents of evodiamine, rutaecarpine and evodine in ethanol extract of Evodia rutaecarpa.

10.
Int J Phytoremediation ; 16(1): 1-13, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24912211

RESUMO

High concentrations of heavy metals and organic pollutants in municipal sewage sludge are key factors limiting its use in agriculture. The objectives of this study were to decrease the heavy metal and polycyclic aromatic hydrocarbon concentrations in sewage sludge by phytotreatment and to determine, in a field experiment, whether co-planting is more effective than using a mono-crop of Sedum alfredii. Four treatments were used in the plot experiment: no sludge, no plants, S. alfredii and co-planting S. alfredii and Alocasia marorrhiza. The results showed that co-planting produced tubers and shoots of A. marorrhiza that were suitable as a safe animal feed and good organic K fertilizer, respectively. Co-planting was more effective than mono-planting at reducing concentrations of total Zn and diethylenetriaminepentaacetic acid (DTPA)-extractable Zn, Cd, and Cu in the sludge. Co-planting decreased the concentrations of DTPA-extractable heavy metals and benzo[a]pyrene (B[a]P) in the sludge significantly compared with the unplanted sludge. Decreases of 87, 75, 85, 31, and 64% were obtained for B[a]P and DTPA-extractable Zn, Cd, Cu, and Pb, respectively, compared with the fresh sludge. These results indicate that co-planting can reduce significantly the environmental risks associated with heavy metals and B[a]P in sewage sludge for further disposal.


Assuntos
Alocasia/metabolismo , Metais Pesados/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Sedum/metabolismo , Esgotos/química , Alocasia/crescimento & desenvolvimento , Benzo(a)pireno/análise , Benzo(a)pireno/metabolismo , Biodegradação Ambiental , Biomassa , China , Metais Pesados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Sedum/crescimento & desenvolvimento , Solo/química , Poluentes do Solo/análise , Poluentes do Solo/metabolismo , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/metabolismo
11.
Hum Reprod ; 28(4): 1135-43, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23406970

RESUMO

STUDY QUESTION: Do genetic polymorphisms which influence age at menarche in women of European ancestry also influence women of Chinese ancestry? SUMMARY ANSWER: Many genetic variants influencing age at menarche in European populations appear to impact Chinese populations in a similar manner. WHAT IS KNOWN AND WHAT THIS PAPER ADDS: Prior genome-wide association studies have uncovered 42 SNPs associated with age at menarche in European populations. This study is the first to demonstrate that many of the genetic determinants of age at menarche are shared between European and Chinese women. PARTICIPANTS AND SETTING: We evaluated 37 of 42 SNPs identified as associated with age at menarche from a recent, large meta-analysis, consisting primarily of women of European ancestry, in a population of 6929 Chinese women from Shanghai, China. We also constructed weighted genetic risk scores (GRSs) combining the number of effect variants for all 37 SNPs, or only the SNPs associated with age at menarche among our study population, to evaluate their joint influence on age at menarche. MAIN RESULTS: For 32 of the 37 evaluated variants, the direction of the allele associations were the same between women of European ancestry and women of Chinese ancestry (P = 3.71 × 10(-6), binomial sign test); 9 of these were statistically significant. Subjects in the highest quintile of GRSs began menarche ∼5 months later than those in the lowest quintile. BIAS, LIMITATIONS AND GENERALIZABILITY TO OTHER POPULATIONS: Age at menarche was obtained by self-report, which can be subject to recall errors. The current analysis was restricted to loci which met or approached GWAS significance thresholds and did not evaluate loci which may act predominantly or exclusively in the Chinese population. The smaller sample size for our meta-analysis compared with meta-analyses conducted in European populations reduced the power to detect significant results. STUDY FUNDING/COMPETING INTERESTS: This study was supported, in part, by grants from US National Institutes of Health (grants R01CA124558, R01CA090899, R01CA070867; R01CA064277 and R01CA092585 and UL1 RR024975), Ingram professorship funds and Allen Foundation funds. There are no competing interests to declare.


Assuntos
Povo Asiático/genética , Estudo de Associação Genômica Ampla , Menarca/genética , Polimorfismo de Nucleotídeo Único , População Branca/genética , Adolescente , Adulto , Fatores Etários , China , Feminino , Humanos
12.
BJOG ; 115(1): 5-13, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18053098

RESUMO

BACKGROUND: As an alternative to electric vacuum aspirations (EVA), there is an increasing interest in using manual vacuum aspiration (MVA). OBJECTIVE: To compare the safety, efficacy and acceptability of MVA with those of EVA for first-trimester abortion. SEARCH STRATEGY: We searched MEDLINE, EMBASE, Cochrane Library and Chinese Biomedical Database in all language, together with reference lists of retrieved papers. SELECTION CRITERIA: Randomised controlled trials comparing MVA with EVA for first-trimester abortion were included. The outcomes are complete abortion rate, uterine perforation rate, blood loss, pain perception and acceptability. DATA COLLECTION AND ANALYSIS: Two reviewers independently extracted the data. Results from the trials were combined to calculate relative risks (RRs) or risk differences for dichotomous outcomes and weighted mean differences (WMDs) for continuous outcomes, together with 95% CIs. MAIN RESULTS: Ten trials were included, involving 1660 women. Generally, the methodological quality was poor. There were no statistically significant differences, comparing MVA with EVA, in complete abortion rate (RR 1.00; 95% CI 0.99-1.02) and participants' satisfaction (RR 1.02; 95% CI 0.87-1.20). In participants with less than 50 days of gestational age, less blood loss (WMD -1.84; 95% CI -2.45 to -1.23) and less severe pain perception (RR 0.04; 95% CI 0.01-0.12) were reported during the MVA procedure, whereas the operation time was shorter (WMD 0.32; 95% CI 0.02-0.63) in the EVA procedure. AUTHOR'S CONCLUSIONS: There is some evidence that MVA is as effective and acceptable as EVA and might be safer than EVA.


Assuntos
Aborto Induzido/métodos , Curetagem a Vácuo/métodos , Vácuo-Extração/métodos , Feminino , Humanos , Dor/etiologia , Satisfação do Paciente , Hemorragia Pós-Parto , Gravidez , Primeiro Trimestre da Gravidez , Ensaios Clínicos Controlados Aleatórios como Assunto
14.
Sens Actuators B Chem ; 77(3): 614-9, 2001 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-12194178

RESUMO

This paper presents a wireless, remote query ammonia sensor comprised of a free-standing magnetoelastic thick-film coated with a polymer, poly(acrylic acid-co-isooctylacrylate), that changes mass in response to atmospheric ammonia concentration. The mass of the polymer layer modulates the resonant frequency the ferromagnetic magnetoelastic substrate, hence by monitoring the frequency response of the sensor, atmospheric NH3 concentration can be determined remotely, without the need for physical connections to the sensor or specific alignment requirements. The effect of copolymer composition, polymer film thickness, and relative humidity level (RH) on the sensitivity of the sensor were investigated. The sensor linearly tracks ammonia concentration below 0.8 vol.%, and tracks higher concentrations logarithmically; within the linear calibration range, a 0.02 vol.% change in NH3 concentration can be detected.


Assuntos
Acrilatos , Amônia/análise , Monitoramento Ambiental/instrumentação , Atmosfera/análise , Automação , Elasticidade , Estudos de Avaliação como Assunto , Umidade , Magnetismo , Polímeros
15.
J Environ Monit ; 2(6): 556-60, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11296740

RESUMO

This paper presents a wireless, passive, remote query CO2 sensor comprising a ribbon-like magnetoelastic thick-film coated with a mass-changing CO2 responsive polymer synthesized from acrylamide and isooctylacrylate. In response to a magnetic field impulse, the magnetostrictive magnetoelastic sensor vibrates at a characteristic resonant frequency that is inversely dependent upon the mass of the attached CO2 responsive polymer. The mechanical vibrations of the magnetostrictive sensor launch magnetic flux, which can be detected remotely using a pickup coil. By monitoring the resonant frequency of the passive sensor, the atmospheric CO2 concentration can be determined without the need for physical connections to the sensor or specific alignment requirements. The effect of humidity and the CO2 responsive copolymer composition on the measurement sensitivity are reported. Greatest sensitivity is achieved with a polymer comprising a 1:1 mole ratio of acrylamide to isooctyl acrylate. A 0.7% change in atmospheric CO2 concentration can be detected for a 20 microns thick polymer coated sensor.


Assuntos
Poluição do Ar/análise , Dióxido de Carbono/análise , Monitoramento Ambiental/instrumentação , Acrilamida , Umidade , Magnetismo , Polímeros , Sensibilidade e Especificidade
16.
Sens Actuators B Chem ; 71(1-2): 112-7, 2000 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-12192686

RESUMO

A remote query magnetoelastic pH sensor comprised of a magnetoelastic thick-film coated with a mass-changing pH-responsive polymer is described. In response to a magnetic query field the magnetoelastic sensor mechanically vibrates at a characteristic frequency that is inversely dependent upon the mass of the attached polymer layer. As the magnetoelastic sensor is magnetostrictive the mechanical vibrations of the sensor launch magnetic flux that can be detected remotely from the sensor using a pickup coil. The pH responsive copolymer is synthesized from 20 mol% of acrylic acid and 80 mol% of iso-octyl acrylate and then deposited onto a magnetoelastic film by dip-coating. For a 1 micrometer polymer coating upon a 30 micrometer thick Metglas [The Metglas alloys are a registered trademark of Honeywell Corporation. For product information see: http://www.electronicmaterials.com:80/businesses/sem/amorph/page5_1_2.htm.] alloy 2826MB magnetoelastic film between pH 5 and 9 the change in resonant frequency is linear, approximately 285 Hz/pH or 0.6%/pH. The addition of 10 mmol/l of KCl to the test solution decreases the sensitivity of the polymer approximately 4%.


Assuntos
Acrilatos/química , Técnicas Biossensoriais/instrumentação , Magnetismo , Polímeros/química , Calibragem , Elasticidade , Concentração de Íons de Hidrogênio , Potássio
17.
Biomed Environ Sci ; 9(2-3): 144-8, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8886325

RESUMO

Biochemical evidence on lens culture suggests that antioxidant nutrients can protect lens against peroxidation caused by radiation. A case-control study was carried out on 262 middle aged (45-54) and aged (55-64) subjects. The relationship between biochemical markers of antioxidant status and senile lens changes (including cataract) was examined in 131 subjects with senile lens changes and 131 control subjects with clear lens. Antioxidant status was measured using plasma and erythrocyte glutathione peroxidase, erythrocyte superoxide dismutase and catalase activity and plasma levels of vitamin E and vitamin A. Subjects were grouped by age and sex. The results were as follows: (1) The subjects with lens changes tended to have lower plasma levels of vitamin E and vitamin A, lower activity of several antioxidant enzymes and higher level of MDA. (2) The subjects with senile lens changes had significantly lower erythrocyte glutathione peroxidase level. (3) In the middle-aged group, subjects with senile lens changes were observed to have lower erythrocyte and plasma glutathione peroxidase level than those without senile lens changes. The results suggest that appropriate amount of antioxidant nutrients might be expected to prevent or retard the process of lens changes.


Assuntos
Envelhecimento/metabolismo , Antioxidantes/metabolismo , Catarata/metabolismo , Micronutrientes/farmacologia , Estudos de Casos e Controles , Catalase/sangue , Catarata/epidemiologia , Catarata/prevenção & controle , Feminino , Glutationa Peroxidase/sangue , Humanos , Masculino , Malondialdeído/sangue , Pessoa de Meia-Idade , Prevalência , Vitamina E/sangue
18.
Biomed Environ Sci ; 7(2): 109-15, 1994 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7946005

RESUMO

The activities of glutathione peroxidase (GSH-Px), glutathione reductase (GSSG-R), superoxide dismutase (SOD) and the contents of malondialdehyde (MDA) and free radicals were measured, and the morphological changes were observed in the lens of control rats, selenium-deficient (SeD) and/or vitamin E deficient (VED) rats. The activities of GSH-Px in the lens of SeD rats decreased significantly. The GSH-Px activities of lens were positively related to erythrocytes selenium level. There was a free radical at g = 2.0015 in the rat lens of all groups, but the content of free radicals in the lens of SeD group was significantly higher than that of the control group. The free radical content of lens was negatively related to erythrocytes selenium level, as well as the GSH-Px activities in the lens. In vitro, ultraviolet radiation caused the generation of another kind of free radical (g = 2.0097) in the lens of all groups, but the amount of the free radical in the lens of the SeD group was also significantly higher than that of the control group. The activities of SOD and GSSG-R in VED rat lens were significantly decreased. The amount of MDA in the lens of SeD and/or VED rats were significantly increased. The results showed that the decrease of antioxidative capability in the lenses of SeD and/or VED rats accelerated the lipid peroxidation and generation of free radicals. Although only early morphological changes in SeD and/or VED rat lens were observed, it is considered that selenium and vitamin E deficiency may be involved in the occurrence of cataract.


Assuntos
Cristalino/metabolismo , Selênio/deficiência , Deficiência de Vitamina E/metabolismo , Animais , Catarata/etiologia , Feminino , Radicais Livres/metabolismo , Cristalino/enzimologia , Cristalino/patologia , Peroxidação de Lipídeos , Masculino , Ratos , Ratos Wistar , Deficiência de Vitamina E/enzimologia , Deficiência de Vitamina E/patologia
19.
Zhonghua Fu Chan Ke Za Zhi ; 29(5): 278-9, 317, 1994 May.
Artigo em Chinês | MEDLINE | ID: mdl-7956551

RESUMO

The fetal transverse cerebellar diameter (CD), biparietal diameter(BPD), abdominal circumference (AC) and femur length(FL) were measured by B-type ultrasonography on 222 normal pregnant women with one week before the expected date of confinement (EDC) and their correlations with birth weight of newborns were computerized. Single factorial analyses showed the best correlation was between CD and birth weight (R = 0.913 4) where as the R value for birth weight and AC, BPD, FL was 0.739 5, 0.612 5, 0.347 6 respectively. The F value of CD on stepwise regression analysis was the highest (F = 1001.95) while that of AC and BPD was 4.55, 4.36 respectively (P < 0.05). Then the regression equations of single double and triple factors were established. It was confirmed by clinical findings that the equation of log(BW) = 2,8844 + 0.01416 x CD was the most reliable one in predicting the birth weight. The error rate was less than 10% in 96% of the newborns.


Assuntos
Peso ao Nascer , Cerebelo/diagnóstico por imagem , Ultrassonografia Pré-Natal , Antropometria , Feminino , Humanos , Recém-Nascido , Gravidez , Terceiro Trimestre da Gravidez
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