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OBJECTIVE: To establish a method for detecting triphenyl phosphate( TPP) in the workplace air by gas chromatography. METHODS: TPP in the air of workplace was collected with glass fiber filter paper,desorbed with ether,separated by HP-5 gas chromatographic column,and detected by flame photometric detector. RESULTS: This method has good linear range of 12. 50-800. 00 mg/L,with the correlation coefficient of 0. 999 9. The detection limit was 0. 78 mg/L,and the minimum detectable concentration was 0. 09 mg/m3(sample volume was 45 L). Desorption efficiency was 97. 2%-99. 4%; standard recovery rate was 99. 5%-100. 3%. The within-run relative standard deviation( RSD) was 2. 7%-3. 4%and the between-run RSD was 1. 4%-3. 2%. The sampling efficiency was 99. 6%-100. 0%. The samples could be stored at room temperature for at least 14 days. CONCLUSION: The method is simple,accurate and highly sensitive for detecting TPP in workplace air.
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Objective To observe the prevalence and risk factors of chronic low back pain in puerperas after childbirth.Methods Eight hundred and eighty-one puerperas were selected,among whom 459 cases had uterine-incision delivery,and 422 cases had spontaneous delivery.The age,height and weight of pregnant women,birth weight of newborn,history of preoperative low back pain,parity and mode of delivery were recorded.The rate of chronic low back pain occurring within 1 month after childbirth and continuing for 3 months was recorded by telephone.The factors with P values less than 0.05 would enter the Logistic regression analysis to screen the risk factors of chronic low back pain.Results Two hundred and fifty-nine puerperas (259/881,29.4％) appeared chronic low back pain,of whom 157 puerperas (157/459,34.2％)delivered by uterine-incision and 102 puerperas (102/422,24.2％) delivered spontaneously,and the difference was statistically significant (P ＜ 0.01).Six hundred and fifty-eight puerperas had no history of preoperative low back pain,and 150 puerperas (150/658,22.8％) appeared newly developed chronic low back pain.Logistic regression analysis showed that mode of delivery,parity and history of preoperative low back pain were the risk factors of chronic low back pain.Condusions The rate of chronic low back pain in puerperas after childbirth is 29.4％,and the newly developed chronic low back pain is 22.8％.Uterineincision delivery,multiparity and history of preoperative low back pain are the risk factors of chronic low back pain for puerperas after childbirth.
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The purpose of the study was to investigate the impact of rat cytomegalovirus(RCMV) infection on the development of the nervous system in rat embryos,and to evaluate the involvement of Wnt signaling pathway key molecules and the downstream gene neurogenin 1(Ngn1) In RCMV infected neural stem cells(NSCs).Infection and control groups were established,each containing 20 pregnant Wistar rats.Rats in the infection group were inoculated with RCMV by intraperitoneal injection on the first day of pregnancy.Rat E20 embryos were taken to evaluate the teratogenic rate.NSCs were isolated from E13 embryos,and maintained in vitro.We found:1) Poor fetal development was found in the infection group with low survival and high malformation rates.2) The proliferation and differentiation of NSCs were affected.In the infection group,NSCs proliferated more slowly and had a lower neurosphere formation rate than the control.The differentiation ratio from NSCs to neurons and glial cells was significantly different from that of the control,showed by immunofluorescence staining.3) Ngn1 mRNA expression and the nuclear β-catenin protein level were significantly lower than the control on day 2 when NSCs differentiated.4) The Morris water maze test was performed on 4-week pups,and the infected rats were found worse in learning and memory ability.In a summary,RCMV infection caused abnormalities in the rat embryonic nervous system,significantly inhibited NSC proliferation and differentiation,and inhibited the expression of key molecules in the Wnt/β-catenin signaling pathway so as to affect NSCs differentiation.This may be an important mechanism by which RCMV causes embryonic nervous system abnormalities.
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The establishment of clinical medicine with professional degree is an important reformation of high-level professionals in medical field. With the expansion of the number of postgraduates of clinical medicine with professional degree, how to establish and perfect the training mode and how to improve the training quality has become an important research for the postgraduate education with professional degree. This paper discusses the establishment and perfection of training mode of full-time postgraduates of clinical medicine with professional degree by combining the documents and development of professional degree in my university.
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Objective To observe the preemptive analgesia effects of katamine and elonidine, and to find out the influence of preemptive on stress responses. Methods 36 patients with hysteromyoma undergone hysteromyomec-tomy were randomly assigned to three groups (n = 12 each group) :group Ⅰ , control group, without preemptive analge-sia,the patients in control group were given continous epidural analgesia with 2% lidoeaine 12 - 14ml. Group Ⅱ ,the patients were injected 0. 6mg/kg katamine into epidural analgesia 30 minutes before operation. Group Ⅲ,the patients were injected 0. 6mg/kg katamine and 1.5μg/kg clonidine into epidural analgesia 30 minutes before operation. The patients in three groups were recorded VAS score on 2h ,4h ,6h, 12h ,24h after operation, also recorded the change of epinephrine(E) and norepinephrine(NE) and sensation and movement recovery time after operation. The side effects such as dizziness nausea,vomit,and exited talking were observed during the operation. Results The VAS score were significantly different between group Ⅰ ,Ⅱ and Ⅲ. The levels of E and NE in plasma in group Ⅰ were increased more than group Ⅱ and Ⅲ within 24 hours after operation, also there is significant difference in group Ⅱ compared with group Ⅲ in T1 ,T2 ,T3. The time of sensation and movement recovery were remarkably longer in group Ⅲ com-pared with group Ⅰ and Ⅱ, showing significant difference. There were no significant difference in side effects after operation in three groups. Conclusion The preemptive analgesia of kutamine and colnidine can relieve the pain of lower abdominal surgery and stress response after operation,and it do not increase the side effects.
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By the survey of topic selection of medical master's dissertation for candidates with the same educational level,the writers think that the decided topics should be in close relation to their respective subjects and the operational and technical conditions of their institutes and the training institutes should be taken into full consideration.The decided topics should enhance theoretical and practical values and will be achieved in the required time as well.
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Huntington's disease (HD) is an autosomal dominant neurodegenerative disease. A cardinal histopathologic feature of HD is the progressive loss of striatal medium spiny neurons. As there is no effective treatment for this fatal disease so far, we explore the therapeutic potential of nortriptyline to identify drugs that might be effective treatments for HD. N548mu [ 1955-128] huntingtin stable ST14A cell line was cultured and incubated in the presence or absence of serial concentrations of nortriptyline. Then R6/2 transgenic HD mice were treated with nortriptyline from five to twenty-one weeks of age. Nortriptyline protected striatal cells expressing mutant huntingtin when shifted to a nonpermissive temperature. Nortriptyline delay the disease onset to 127 d in R6/2 mice as compared with 102 d in saline-treated controls, but nortriptyline did not significantly delay mortality. As a gross marker of lack of systemic toxicity, there was no significant difference in the weight of the treated and control R6/2 mice. The results demonstrate that clinically reasonable doses of one of the identified drugs, nortriptyline, delays disease onset in a mouse model of the disease more than any previously identified compound. The most desirable features of a drug for HD are minimal toxicity and the ability to extend symptom-free living. Nortriptyline appears to be one such good candidate.
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Objective:To study the effects of 17-? estradiol on capillary ultrastructure of medulla oblongata in ovariectomized rats. Methods: The 30 adult femal rats were randomly divided into ovariectomy group(A group), estradiol group(B group) and sham- ovariectomy group(C group).The rats of A group and B group were bilaterally ovariectomized ,Which were injected with normalsaline 0.1 ml/d), 17-? estradiol(20 ?g/kg?d -1) ,The rats of D group were sham- ovariectomy ,animals were injected with normalsaline(0.1 ml/d), for 6 weeks. Results:(1)The level of serum estradiol of A group was significantly decreased compared with C group(P
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The animal experiment studies have demonstrated that hyperthermia is a strong teratogen to many kinds of animal with high incidence of neural tube defects(NTD).Epidermiological investigation showed that hyperthermia was closely related to the acencephaly and excenphaly in human being,but little was known about the distinct mechanism of NTD induced by hyperthermia.In order to study the developmental mechanism of NTD induced by hyperthermia,we observed the effects of hyperthermia on the neuroepithelial cells in primary culture.The neural tubes of the hamster embryos on 10 d after fertilization were obtained.the neuroepithelia were dissociated and then seeded at the density of 1×106 cells per well.The cells were divided into experimental and control groups randomly.The experimental groups were exposed to 42 C for 20 min,whereas groups exposed to 37 Cserved as control.After treatment of hyperthermia,the cells were incubated continuously at 37 C in a 95%air/5%CO2 humidified incubator,the culture was terminated after different intervals.Phase-contrast microscopy.scanning electron microscopy.transmission electron microscopy,MTT assay,agarose gel electrophoresis analysis,TUNEL detection,immunocytochemistryand image analysis were made.The results of the experimental groups indicated that the floating cells and apoptotic cells increased in number,the neurites of the cells were shortened even disappeared,the survival cells decreased in number,the ultrastructure of the cells demonstrated distinct abnormal changes,the function of mitochondria was impaired,the expressions of both bcl-2 and bax were abnormal.The above results suggest that hyperthermia may induce apoptosis of neuroepithelial cells,duringwhich bcl-2 and bax genes may play important regulatory roles.
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Objective Constructing golden hamster neural tube cDNA library in order to detect new genes associated with development of neural tube and neural tube defects. Methods Total RNAs were isolated from neural tube using TRIZOL Reagent; Doublestranded cDNAs were synthesized from total RNAs using LD-PCR method; The dsc DNAs were digested by proteinase K and Sfi Ⅰ, less than 500?bp fragments were separated by CHROMA SPIN-400, and then the cDNAs were ligated to ? TriplEX-2 vector.After packaging,the neural tube cDNA library was constructed. Results The titer of neural tube cDNA library was 1.5?10 6?pfu/ml.The recombination rat was 99%.The average insert was larger than 1?kb.Conclusion Our successfully constructed cDNA library is a full-length library with high efficiency,and can be used to detect the genes related to development of neural tube and neural tube defects.