Methanobacteriales, and Obesity
Associations among Organochlorine Pesticides, Methanobacteriales,and Obesity in Korean Women
Hae-Sook Lee1,Je-Chul Lee2,In-Kyu Lee3,Hyo-Bang Moon4,Yoon-Seok Chang5,David R.Jacobs,Jr.6,7, Duk-Hee Lee8*
1Department of Public Health Graduate School,Kyungpook National University,Daegu,Korea,2Department of Microbiology,Kyungpook National University School of Medicine,Daegu,Korea,3Department of Endocrinology,Kyungpook National University School of Medicine,Daegu,Korea,4Department of Environmental Marine Sciences,College of Science and Technology,Hanyang University,Ansan,Korea,5School of Environmental Science and Engineering,POSTECH,Pohang,Korea,6Division of Epidemiology,School of Public Health,University of Minnesota,Minneapolis,Minnesota,United States of America,7Department of Nutrition,University of Oslo,Oslo, Norway,8Department of Preventative Medicine,School of Medicine,Kyungpook National University,Daegu,Korea
Abstract
Background:Although Methanobacteriales in the gut has recently been linked to obesity,no study has examined the hypothesis that waist circumference,a marker of visceral obesity,are positively associated with Methanobacteriales in the general population.Since Methanobacteriales increase in a petroleum-contaminated environment to biodegrade petroleum as one way of autopurification,we also hypothesized that high body burden of highly lipophilic petroleum-based chemicals like organochlorine pesticides(OCPs)is associated with higher levels of Methanobacteriales in the gut.
Methodology/Principal Findings:Among83Korean women who visited a community health service center for a routine health checkup,quantitative real-time PCR(qPCR)based on16S rDNA was used to quantify Methanobacteriales in feces.
Nine OCPs were measured in both serum and feces of16subjects.Methanobacteriales were detected in32.5%(27/83 women).Both BMI and waist circumference among women with Methanobacteriales were significantly higher than in women without Methanobacteriales(P=0.04and P=0.01,respectively).Also,Methanobacteriales levels in feces were positively associated with BMI and waist circumference(r=+0.23and P=0.03for both).Furthermore,there were significant correlations between feces Methanobacteriales levels and serum concentrations of most OCPs,including with cis-nonachlor (r=+0.53,P,0.05),oxychlordane(r=+0.46,P,0.1),and trans-nonachlor(r=+0.43,P,0.1).Despite high correlations of serum and feces concentrations of most OCPs,feces OCP concentrations were not clearly associated with feces Methanobacteriales levels.
Conclusion/Significance:In this cross-sectional study,the levels of Methanobacteriales in the human gut were associated with higher body weight and waist circumference.In addition,serum OCP concentrations were positively correlated with levels of Methanobacteriales.There may be a meaningful link among body burden of OCP,Methanobacteriales in the gut, and obesity in the general population.
Citation:Lee H-S,Lee J-C,Lee I-K,Moon H-B,Chang Y-S,et al.(2011)Associations among Organochlorine Pesticides,Methanobacteriales,and Obesity in Korean Women.PLoS ONE6(11):e27773.doi:10.1371/journal.pone.0027773
Editor:Raul M.Luque,University of Cordoba,Spain
Received June14,2011;Accepted October25,2011;Published November17,2011
Copyright:?2011Lee et al.This is an open-access article distributed under the terms of the Creative Commons Attribution License,which permits unrestricted use,distribution,and reproduction in any medium,provided the original author and source are credited.
Funding:This work was partly supported by the National Research Foundation of Korea(NRF)grant funded by the Korean government(MEST)(no.2011-0004692).The funder had no role in study design,data collection and analysis,decision to publish,or preparation of the manuscript.
Competing Interests:The authors have declared that no competing interests exist.
*E-mail:lee_dh@knu.ac.kr
Introduction
Methanogens are microbes that produce methane gas from various substrates such as H2and CO2,acetate,and methylamine. They were identified as belonging to the domain archaea in the 1970s[1].Pathogenicity,such as tissue invasion and toxin release commonly observed with classic pathogens,has not yet been described for methanogens[2].Although causal pathways are not clear,significant associations have been observed between methanogens and periodontitis,colon cancer,or diverticulosis[2]. Methanogens were recently linked to obesity[3].Many dietary components that are resistant to initial digestion in the small intestine are subsequently fermented by the microbial community of the large intestine,producing short-chain fatty acids(SCFAs) that are absorbed across the colonic mucosa[4].These SCFAs have been estimated to provide10%of daily caloric intake[4].In experimental mice,the presence of methanogens in the colon promotes calorie harvest and adiposis through improved efficiency of polysaccharide fermentation by the Bacteroidetes and the Firmicutes,the primary bacterial fermenters in the gut[3]. Fermentation of polysaccharides generates SCFAs,principally acetate,propionate,and butyrate,as well as other organic acids and gases like H2and CO2[5].Accumulation of H2inhibits bacterial NADH dehydrogenases,thereby reducing the yield of ATP.Studies in man-made bioreactors have shown that removal of H2by methanogens could promote obesity by improving fermentation efficiency of dietary polysaccharides[3].
Despite the clear experimental evidence[3],however,human studies on the associations between methanogens and obesity have shown inconsistent results[6,7,8,9].One small-scale human study
with9study subjects also observed an association between methanogens and extreme obesity[7].However,in the other studies,methanogens were increased in anorectic patients or lean subjects[6,8,9].To our knowledge,no study has explored associations between gut methanogens and waist circumference, a marker of visceral obesity,in the general population.Different from subcutaneous fat underneath the skin,visceral fat surround-ing vital organs is strongly linked to various obesity-related chronic diseases[10].
On the other hand,it is unclear which specific environmental factors determine the levels of methanogens in the human gut, although both shared and unique environmental factors have been suggested in a twin study as determinants of the ecology of methanogens in the gut[11].In the field of environmental microbiology,methanogens have been reported to biodegrade petroleum hydrocarbons in polluted environments[12].There-fore,this kind of microorganism tends to increase in places with petroleum contamination as one way of autopurification and is artificially used to remove petroleum-based pollutants in environ-ments[13].Therefore,we hypothesized that increased body burden of petroleum-based man-made chemicals would promote methanogens in human gut.
In relation to this hypothesis,recent epidemiological studies on Persistent Organic Pollutants(POPs),very lipophilic man-made chemicals produced based on petroleum,are highly relevant.For example,environmental exposure to POPs is strongly linked to a variety of chronic diseases and obesity in the general population [14,15,16,17,18,19].POPs are very slowly eliminated from the body via feces,following two major mechanisms of biliary and intestinal excretion[20].Therefore,persons with a high body burden of POPs may also have higher levels of POPs in their feces. Another direct source of POPs in feces is POPs contained in food. Therefore,it is reasonable that methanogens may increase to biodegrade POPs in the feces,similar to the autopurification commonly observed in petroleum-contaminated environments. This study was primarily performed to explore if there are relations of Methanobacteriales,the predominant methanogenic archaea in the human gut[7],with body mass index or waist circumference in Korean women.Further,we conducted a pilot study to examine the associations between serum or stool concentrations of organochlorine pesticides(OCPs),one subclass of POPs,and Methanobacteriales in feces in a subsample of16 women.
Methods
Human subjects and survey methods
We studied83Korean women who visited a community health service center for a routine health checkup in Koryung County, Korea.They did not have current gastrointestinal symptoms or a history of chronic gastrointestinal problems.None of them lived in the same household,and none had received any antibiotic or probiotic agents in the3-month period before the collection of fecal samples.This study was conducted with the approval from the Institutional Review Board at the Kyungpook National University Hospital.Written informed consent was obtained from all study subjects.
Height and body weight were measured using standard methods in light clothes.Body mass index(BMI)was calculated as weight divided by height squared(kg/m2).Waist circumference was measured in the supine position midway between the lowest rib and the iliac crest.Blood samples were obtained by venipuncture in the morning after overnight fasting.Participants were also asked to collect the last part of stools when they defecated.After collection,both blood and stool samples were frozen at270u C until the molecular analyses were conducted.Fasting glucose, triglycerides,and high density lipoprotein(HDL)cholesterol were determined by enzymatic methods using ADVIA1650(Bayer Inc., USA).
Quantification of Methanobacteriales in feces Quantitative real-time PCR(qPCR)was used to quantify Methanobacteriales.The genomic DNA was extracted from the frozen stool samples(wet weight0.2g)using the QIAamp DNA Stool Kit(Qiagen)according to the manufacturer’s instructions. We performed16S rDNA-targeted qPCR with TaqMan detection kit(Applied Biosystems).The Methanobacteriales-specific primers and probe were MBT-NF(59-TCG CAA GAC TGA AAC TTA AAG GAA-39),MBT-NR(59-CGG CGT TGA ATC CAA TTA AAC-39),and MBT-N-probe(59-AGC ACC ACA ACG CGT GGA GCC-39)[7].Analyses were performed in a total volume of 15m l containing the following:7.5m l of Universal PCR Mater Mix(TaqMan),1.5m l of oligonucleotide mixture(4m M of each primer and1m M of FAM-labeled probe),and1m l of template DNA.The amplification program consisted of one cycle of95u C for10min and then40cycles of95u C for15s and60u C for15s. qPCR was performed in an ABI Prism7500cycler(Applied Biosystems).Standard curves were created using serial10-fold dilution of the standard plasmid DNA corresponding to26102to 261011copies/ml.The plasmid DNA standards of target organisms were prepared from the representative16S rDNA clones,which were amplified from stool samples by specific primers and then cloned into pGEM-T vector(Promega).We calculated the copy number of the16S rDNA as follows:grams/ plasmid molecules=(number of base pairs)*(average weight of double stranded DNA)/Avogadro’s number and copy numbers/ template m l(q)=(grams/m l)/(grams/plasmid molecules).Finally, copy number per gram of wet stool=q6D6(50m l)/(0.2g),where D is the dilution factor,50m l is the elution volume in genomic DNA extraction,and0.2g is the wet weight of stool used for DNA extraction.
Measurement of OCPs
For analyses of OCPs in serum and feces,we selected16out of 83subjects based on the results of Methanobacteriales analyses in feces;8from women with Methanobacteriales and8from women without Methanobacteriales.OCPs in serum were analyzed at the laboratory of the School of Environmental Science and Engineer-ing,POSTECH(Pohang,Korea)while OCPs in stool were analyzed at the laboratory of the Department of Environmental Marine Sciences(Ansan,Korea).Both of them used an isotope dilution method with GC-HRMS(gas chromatography-high resolution mass spectrometry).GC-HRMS measurements were performed on a JMS-800D instrument(JEOL,Japan)interfaced with a6890N gas chromatography(Agilent Technologies,USA). Statistical analyses
First,we compared BMI and waist circumference between subjects with and without Methanobacteriales.Next,Pearson correlation coefficients were presented between log transformed count of Methanobacteriales and BMI or waist circumference. Methanobacteriales showed a right-skewed distribution.Also,we presented detection rates of Methanobacteriales according to tertiles of waist circumference.Finally,we presented Pearson correlation coefficients between log transformed concentrations of OCPs in serum or feces with log transformed count of Methanobacteriales.All data were analyzed using SAS version9.1.
Results
Methanobacteriales in feces were detected in27out of83study subjects(32.5%).Among27women with Methanobacteriales,mean and standard deviation of number of Methanobacteriales were 17.6645.1(6107).Table1shows demographic and clinical characteristics of study subjects depending on the presence of Methanobacteriales.BMI or waist circumference of women with Methanobacteriales was statistically significantly higher than those of those without them(P=0.04and P=0.01,respectively).There were no significant differences in age,fasting glucose,triglyceride, total cholesterol,and HDL-cholesterol.
The number of Methanobacteriales had correlation coefficients of +0.23(P=0.03)with both BMI and waist circumference,but lower correlations with other characteristics(Table2).Figure1 shows the detection rate of Methanobacteriales by tertile of waist circumference.Among women with waist circumference,83cm, Methanobacteriales were detected among18.5%while women with
waist circumference83,87cm and$88cm showed detection rates of33.3%and48.2%(P trend=0.03).
Table3shows absolute concentrations of OCPs in serum and feces and their correlations among16women selected to balance presence or absence of methanobacteriales.As concentrations of OCPs in feces were measured based on dry weight while concentrations of OCPs in serum were measured based on lipid weight or wet weight,direct comparison of concentrations between two specimens was difficult.However,correlation coefficients between serum concentrations of OCPs and those of feces were substantial,in particular with b-hexachlorocyclohexane and OCPs belonging to the Chlordane family.In case of OCPs belonging to the DDT family,both p,p;-DDE and p,p;-DDD showed modest positive associations between serum and feces while p,p’-DDT showed an inverse association between these two specimens.
Despite the strong correlations between serum and feces, correlation coefficients with levels of Methanobacteriales were more strongly observed with serum than with feces concentrations of OCPs(Table3).Although most OCPs in serum showed positive associations with levels of Methanobacteriales,in particular cis-nonachlor(r=+0.53,P,0.05),oxychlordane(r=+0.46,P,0.1), and trans-nonachlor(r=+0.43,P,0.1)showed statistically significant or marginally significant correlations.OCPs belonging to the DDT family also showed correlations coefficients of around +0.3to+0.4,although they did not reach statistical significance. Figure2shows a scatter plot beween serum concentrations of the mixture of organochlorine pesticides belonging to the Chlordane family(oxychlordane,trans-Nonachlor,cis-Nonachlor,Heptachlor epoxide)and number of Methanobacteriales among16women. Discussion
In this cross-sectional study,we found that Methanobacteriales were positively associated with BMI and waist circumference among Korean women who had mean BMI around25kg/m2, consistent with the hypothesis that Methanobacteriales promote extraction of energy within the human gut.In addition,persons with high Methanobacteriales in their feces had higher serum concentrations of OCPs,suggesting that the phenomenon of increased Methanobacteriales in an oil-contaminated environment can also be observed in the human gut ecosystem because OCPs
Table
1.General characteristics by presence of
Methanobacteriales(n=83).
Methanobacteriales
Characteristics Present
(n=27)
Absent
(n=56)P value
Mean6standard deviation
Age(years)58.667.359.367.80.71 Body mass index(kg/m2)26.463.224.763.50.04 Waist circumference(cm)88.867.383.669.00.01 Fasting glucose(mg/dl)95.6615.492.7637.70.27 Triglycerides(mg/dl)143.2665.4140.7691.70.58 Total cholesterol(mg/dl)210.6622.7204.1637.50.19 HDL-cholesterol(mg/dl)43.969.645.668.20.29 Percentages(%)
Body mass index$25kg/m266.7%46.4%0.08 Cigarette smoker0.0% 1.8%0.48
Alcohol drinker15.4%7.4%0.27 doi:10.1371/journal.pone.0027773.t001Figure1.Detection rate of Methanobacteriales by
tertiles of waist circumference(n=83).
doi:10.1371/journal.pone.0027773.g001
are typical highly lipophilic man-made petroleum-based chemicals.
Even though there was a clear trend between waist circumfer-ence and the detection rates of Methanobacteriales,the correlation coefficient of +0.23between the number of Methanobacteriales and waist circumference can be interpreted as a weak association.However,considering the predominant role of many life style-related factors contributing to obesity,such as excess energy intake and lack of exercise,the strength of association observed in the current study cannot be dismissed as weak.
An experimental study reported that methanogens could promote obesity by improving fermentation efficiency of dietary polysaccharides [3],but,with the exception of one small scale study [7],previous human studies did not support the experimen-
tal evidence [6,8,9].In one previous human study with 6study subjects by Zhang et al,Methanobacteriales was detected in all 3obese persons with mean BMI of 48.3kg/m 2,but not in 3persons with normal weight with mean BMI of 22.7kg/m [7].On the other hand,Armougom et al compared 20obese subjects with mean BMI of 47.1kg/m 2,9patients with anorexia nervosa with mean BMI of 12.7kg/m 2,and 20normal control with mean BMI of 20.1kg/m 2and reported no difference in the number of Methanobrevibacter smithii,the predominant type of Methanobacteriales in humans,between obese and normal weight subjects.However,they showed that counts of M,smithii were higher among patients with anorexia nervosa with very low BMI compared with normal weight subjects [6].In a followup study by the same research team,Methanobrevibacter smithii was less frequent and significantly less abundant in obese persons with mean BMI of 43.6kg/m 2than controls with mean BMI of 22.1kg/m 2[8].The depletion of Methanobrevibacter smithii among obese healthy subjects with BMI $30kg/m 2compared to lean subjects with BMI ,25kg/m 2also reported by Schwiertz et al [9].
In contrast to the previous studies,which mostly compared mean levels of methanogens between extremely obese patients and normal weight controls,we showed positive associations using continuous BMI or waist circumference and levels of Methano-bacteriales using correlation coefficients in the general population.Also,considering the distribution of BMI,our participants were closer to control subjects of the previous studies,rather than the extremely obese patients.Therefore,even though at the first glance the current study seems to be consistent with the results of Zhang et al.[7],but not with others [6,8,9],our study design is quite different from that of either of the other studies and is the only study to address the associations of adiposity and Methano-bacteriales within the range that is relevant to most people.Thus,comparison between the current study and the previous studies is difficult.
The adult intestine contains 10trillion to 100trillion microbial cells and is dominated by members of just two divisions of bacteria,the Bacteroidete s and the Firmicutes .A role for the intestinal microbiota in harvesting energy from food [21]and regulating body fat storage [22]was first proposed in rodents.Germ-free
Table 3.Correlation coefficients among serum concentrations of organochlorine pesticides (OCPs),stool concentrations of OCPs,and levels of Methanobacteriales (n =16{{).
Mean ±standard deviation
Correlation coefficients Characteristics OCPs in serum (ng/g lipid)OCPs in feces {(pg/g){OCPs in serum vs.OCPs in feces OCPs in serum vs.Methanobacteriales OCPs in feces vs.Methanobacteriales p,p ’-DDE 114654.314616676+0.42+0.3320.02p,p ’-DDD 2.161.1235675.1+0.24+0.4020.44*p,p ’-DDT 10.665.9204611620.48*+0.4120.42Oxychlordane 4.161.649.0636.4+0.62**+0.46*+0.19trans-Nonachlor 6.762.9101651.2+0.51**+0.43*+0.15cis-Nonachlor 1.260.629.0614.6+0.49*
+0.53**
20.06Heptachlor epoxide {7.163.2--+0.27-b -Hexachlorocyclohexane 35.5632.1217661647+0.89***+0.33+0.23Hexachlorobenzene
6.763.4
231662928
+0.19
20.07
20.13
*:P ,0.1,**:P ,0.05,***:P ,0.01.{
Heptachlor epoxide was measured only in serum.{
Concentrations of OCPs in feces were presented based on dry weight.{{
8selected at random among the women with no detectable methanobacteriales ,8selected at random among the women with detectable methanobacteriales .doi:10.1371/journal.pone.0027773.t003
Figure 2.Scatter plot beween serum concentrations of mixture of organochlorine pesticides belonging to Chlordane (oxy-chlordane,trans-Nonachlor,cis-Nonachlor,Heptachlor epox-ide)and number of Methanobacteriales (n =16).When one subjects with the highest number of Methanobacteriales (38.76107)was excluded,the correlation coeffficent was 0.45(p =0.09).doi:10.1371/journal.pone.0027773.g002
mice colonized by microbiota increase their body fat and develop insulin resistance despite a30%decrease in food intake.These changes were associated with a dysbiosis in obese mice:an increased representation of the Firmicutes phylum and a reduced representation of the Bacteroidetes phylum[23].However,modifi-cation of the Fermicutes-to-Bacteroidetes ratio is not consistently observed in human[24,25].
In this study,we focused on methanogenic archaea in the gut, rather than the distribution of various microbiota,because we hypothesized that there was a link among POPs,methanogenic archaea,and obesity.In this study,Methanobacteriales were detected in32.5%of study subjects.On the other hand,Methanobacteriales were not detected in control subjects in Zhang et al.’s study[7] while M.smithii were detected in63.3%,88.9%in control subjects in other studies[6,8,9].As all of these studies quantify the counts of Methanobacteriales or M.smithii using RT-PCR on the basis from16S rRNA sequencing,we do not have any explanation for why there were the different detection rates among the studies.On the other hand,when the methane breathing test was used as an indirect marker of methanogens in gut,it was estimated that methanogenic archaea were present at high levels in50–85%of humans[26,27,28].
One important finding from the current study is the relation between Methanobacteriales in feces and serum concentrations of OCPs.To our best knowledge,there has been no previous study which tested this hypothesis.Based on both findings from environmental microbiology which shows the role of methanogens to clear petroleum-contaminated environment by biodegrading petroleum[11,12]and recent epidemiological findings on POPs [14,15,16,17,18,19],we first hypothesized that body burden of POPs would determine the levels of Methanobacteriales in feces.To mark POPs body burden,we measured OCPs in16subjects because OCPs were most strongly associated with obesity-related metabolic dysfunctions in previous studies[14,15,19].Among OCPs,chemicals belonging to the Chlordane family showed the strongest associations with the levels of Methanobacteriale in feces. Interestingly,the Chlordane family was the one which was most strongly and consistently associated with type2diabetes in previous epidemiological studies[15,17].If OCPs in the gut are really important in determining the levels of methanogens in the gut,the increased levels of Methanobrevibacter smithii among patients with anorexia nervosa[6]may be explained because it is reported that weight loss increases serum concentrations of OCPs [29,30,31].Increased serum concentrations of OCPs due to severe weight loss may lead to increased OCP levels and increased methanogens in the gut because concentrations of POPs in feces were positively associated with serum concentrations of POPs as we observed in the current study.
As markers of OCPs in the gut,we measured OCPs in both serum and feces.As far as we know,there has been no previous human study which compared concentrations of OCPs in between serum and feces.In this study,we observed that OCP levels in these two specimens were highly correlated,but only OCPs levels in serum showed significant positive associations with the levels of Methanobacteriales in feces.Intuitively,if OCPs in the gut truly increase the levels of Methanobacteriales in feces,OCP levels in feces, rather than OCP levels in serum,should have shown stronger associations.However,the results were different.This could be related to poor validity and reliability of OCP levels in feces.To collect feces samples,the subjects were asked to collect the last part of stools when they defecated.However,we cannot be sure how well OCP levels in the collected samples represent OCP levels in gut.OCP levels in feces can differ substantially depending on the frequency and quality of defecation as well as recent diet of study subjects.Also,OCPs would not be homogenously distributed in the total mass of feces.As we can collect only a small part of feces to measure OCPs,OCP levels in collected feces likely do not represent the OCP levels in the whole feces.On the contrary, serum concentrations of OCPs are considered as a marker of total body burden of OCPs[32].As OCPs in serum keep being excreted through bile acid and large intestine from body[20], OCP levels in serum may better represent the general pattern of OPCs in gut.
There are several study limitations.First,we did not study other diverse bacteria.However,we had a prior hypothesis about relations the body burden of OCPs,Methanobacteriales in feces,and obesity.Second,as only women were included in the current study,we cannot say that the current finding can be applied to men.Third,OCPs were measured only in a subsample of study subjects for cost reasons.Even though we did see statistically meaningful associations,the interpretation should be cautious because the result was based on only16study subjects.
In this study,we tested the hypothesis which links the body burden of POPs,Methanobacteriales,and obesity.The results are consistent with our hypotheses that body burden of OCPs may determine the levels of Methanobacteriales in the human gut,and that this process can finally lead to increased body weight and waist circumference.Cautious interpretation should be made about causality of these associations,given the current cross-sectional study design.Also,the association between body burden of OCPs and Methanobacteriales in the human gut needs to be confirmed in future studies with more study subjects.Future studies on the role of POPs in the control of methanogens in human gut may be important to understand a more fundamental role of POPs in developing the change of gut microbiota and obesity.
Author Contributions
Conceived and designed the experiments:D-HL I-KL.Performed the experiments:H-SL J-CL H-BM Y-SC.Analyzed the data:H-SL DRJ. Contributed reagents/materials/analysis tools:J-CL H-BM Y-SC.Wrote the paper:H-SL J-CL I-KL DRJ D-HL.
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脐带干细胞综述
脐带间充质干细胞的研究进展 间充质干细胞（mesenchymal stem cells,MSC S ）是来源于发育早期中胚层 的一类多能干细胞[1-5]，MSC S 由于它的自我更新和多项分化潜能，而具有巨大的 治疗价值 ,日益受到关注。MSC S 有以下特点：(1)多向分化潜能，在适当的诱导条件下可分化为肌细胞[2]、成骨细胞[3、4]、脂肪细胞、神经细胞[9]、肝细胞[6]、心肌细胞[10]和表皮细胞[11, 12]；(2)通过分泌可溶性因子和转分化促进创面愈合；(3) 免疫调控功能，骨髓源（bone marrow ）MSC S 表达MHC-I类分子，不表达MHC-II 类分子，不表达CD80、CD86、CD40等协同刺激分子，体外抑制混合淋巴细胞反应，体内诱导免疫耐受[11, 15]，在预防和治疗移植物抗宿主病、诱导器官移植免疫耐受等领域有较好的应用前景；(4)连续传代培养和冷冻保存后仍具有多向分化潜能，可作为理想的种子细胞用于组织工程和细胞替代治疗。1974年Friedenstein [16] 首先证明了骨髓中存在MSC S ，以后的研究证明MSC S 不仅存在于骨髓中，也存在 于其他一些组织与器官的间质中：如外周血[17]，脐血[5]，松质骨[1, 18]，脂肪组织[1]，滑膜[18]和脐带。在所有这些来源中，脐血(umbilical cord blood)和脐带(umbilical cord)是MSC S 最理想的来源，因为它们可以通过非侵入性手段容易获 得，并且病毒污染的风险低，还可冷冻保存后行自体移植。然而，脐血MSC的培养成功率不高[19, 23-24]，Shetty 的研究认为只有6%，而脐带MSC的培养成功率可 达100%[25]。另外从脐血中分离MSC S ，就浪费了其中的造血干/祖细胞(hematopoietic stem cells/hematopoietic progenitor cells,HSCs/HPCs) [26, 27]，因此，脐带MSC S (umbilical cord mesenchymal stem cells, UC-MSC S )就成 为重要来源。 一．概述 人脐带约40 g, 它的长度约60–65 cm, 足月脐带的平均直径约1.5 cm[28, 29]。脐带被覆着鳞状上皮，叫脐带上皮，是单层或复层结构，这层上皮由羊膜延续过来[30, 31]。脐带的内部是两根动脉和一根静脉，血管之间是粘液样的结缔组织，叫做沃顿胶质，充当血管外膜的功能。脐带中无毛细血管和淋巴系统。沃顿胶质的网状系统是糖蛋白微纤维和胶原纤维。沃顿胶质中最多的葡萄糖胺聚糖是透明质酸，它是包绕在成纤维样细胞和胶原纤维周围的并维持脐带形状的水合凝胶，使脐带免受挤压。沃顿胶质的基质细胞是成纤维样细胞[32]，这种中间丝蛋白表达于间充质来源的细胞如成纤维细胞的，而不表达于平滑肌细胞。共表达波形蛋白和索蛋白提示这些细胞本质上肌纤维母细胞。 脐带基质细胞也是一种具有多能干细胞特点的细胞，具有多项分化潜能，其 形态和生物学特点与骨髓源性MSC S 相似[5, 20, 21, 38, 46]，但脐带MSC S 更原始，是介 于成体干细胞和胚胎干细胞之间的一种干细胞，表达Oct-4, Sox-2和Nanog等多
我的梦想高中生英语演讲稿
我的梦想高中生英语演讲稿 my dream hello everyone! it is my great pleasure to share my dream with you today. my dream is to become a teacher. you know being a teacher is a thing that is very valuable and very interesting. i suggest that it must be a great fun to be with children all the day. and if i am a teacher, i can teach my students a lot of knowledge. they might become stronger and cleverer because of me. that is a very contented feeling. china is a developing country. chinese are not that excellent in their intellegent. so teachers in china might be very very important. they can provide the society with a lot of successful people, and make china a better place. do you think that i have a good dream? i will work hard to make my dream become true! thanks~ 我的梦想 你好大家!这是我很高兴能够分享我的梦想与你今天。 我的梦想是成为一名教师。 你知道作为一个教师，是一个东西，这是非常宝贵的，非常有趣。我认为它 必须是一个伟大的乐趣与子女所有。 如果我是一名教师， 我可以教我的学生很多 知识。他们可能会成为强大和聪明，因为我了。这是一个非常知足的感觉。 中国是一个发展中国家。中国人是不是优秀，在他们的智能。所以老师在中 国可能非常非常重要的。 他们可以提供社会了不少成功的人， 使中国成为更美好 的地方。 你认为我有一个很好的梦想，我将努力工作，使我的梦想变成真! [我的梦想高中生英语演讲稿
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精神分裂症的病因及发病机理
精神分裂症的病因及发病机理 精神分裂症病因：尚未明，近百年来的研究结果也仅发现一些可能的致病因素。（一）生物学因素1．遗传遗传因素是精神分裂症最可能的一种素质因素。国内家系调查资料表明：精神分裂症患者亲属中的患病率比一般居民高6.2倍，血缘关系愈近，患病率也愈高。双生子研究表明：遗传信息几乎相同的单卵双生子的同病率远较遗传信息不完全相同 的双卵双生子为高，综合近年来11项研究资料：单卵双生子同病率（56.7%），是双卵双生子同病率（12.7%）的4.5倍，是一般人口患难与共病率的35-60倍。说明遗传因素在本病发生中具有重要作用，寄养子研究也证明遗传因素是本症发病的主要因素，而环境因素的重要性较小。以往的研究证明疾病并不按类型进行遗传，目前认为多基因遗传方式的可能性最大，也有人认为是常染色体单基因遗传或多源性遗传。Shields发现病情愈轻，病因愈复杂，愈属多源性遗传。高发家系的前瞻性研究与分子遗传的研究相结合，可能阐明一些问题。国内有报道用人类原癌基因Ha-ras-1为探针，对精神病患者基因组进行限止性片段长度多态性的分析，结果提示11号染色体上可能存在着精神分裂症与双相情感性精神病有关的DNA序列。2．性格特征：约40%患者的病前性格具有孤僻、冷淡、敏感、多疑、富于幻想等特征，即内向
型性格。3．其它：精神分裂症发病与年龄有一定关系，多发生于青壮年，约1/2患者于20～30岁发病。发病年龄与临床类型有关，偏执型发病较晚，有资料提示偏执型平均发病年龄为35岁，其它型为23岁。80年代国内12地区调查资料：女性总患病率（7.07%。）与时点患病率（5.91%。）明显高于男性（4.33%。与3.68%。）。Kretschmer在描述性格与精神分裂症关系时指出：61%患者为瘦长型和运动家型，12.8%为肥胖型，11.3%发育不良型。在躯体疾病或分娩之后发生精神分裂症是很常见的现象，可能是心理性生理性应激的非特异性影响。部分患者在脑外伤后或感染性疾病后发病；有报告在精神分裂症患者的脑脊液中发现病毒性物质；月经期内病情加重等躯体因素都可能是诱发因素，但在精神分裂症发病机理中的价值有待进一步证实。（二）心理社会因素1．环境因素①家庭中父母的性格，言行、举止和教育方式（如放纵、溺爱、过严）等都会影响子女的心身健康或导致个性偏离常态。②家庭成员间的关系及其精神交流的紊乱。③生活不安定、居住拥挤、职业不固定、人际关系不良、噪音干扰、环境污染等均对发病有一定作用。农村精神分裂症发病率明显低于城市。2．心理因素一般认为生活事件可发诱发精神分裂症。诸如失学、失恋、学习紧张、家庭纠纷、夫妻不和、意处事故等均对发病有一定影响，但这些事件的性质均无特殊性。因此，心理因素也仅属诱发因
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员会），负责对脐带血造血干细胞库设置的申请、验收和考评提出论证意见。专家委员会负责制订脐带血 造血干细胞库建设、操作、运行等技术标准。 第八条脐带血造血干细胞库设置的申请者除符合国家规划和布局要求，具备设置一般血站基本条件之外， 还需具备下列条件： （一）具有基本的血液学研究基础和造血干细胞研究能力； （二）具有符合储存不低于1 万份脐带血的高清洁度的空间和冷冻设备的设计规划； （三）具有血细胞生物学、HLA 配型、相关病原体检测、遗传学和冷冻生物学、专供脐带血处理等符合GMP、 GLP 标准的实验室、资料保存室； （四）具有流式细胞仪、程控冷冻仪、PCR 仪和细胞冷冻及相关检测及计算机网络管理等仪器设备； （五）具有独立开展实验血液学、免疫学、造血细胞培养、检测、HLA 配型、病原体检测、冷冻生物学、 管理、质量控制和监测、仪器操作、资料保管和共享等方面的技术、管理和服务人员； （六）具有安全可靠的脐带血来源保证； （七）具备多渠道筹集建设资金运转经费的能力。 第九条设置脐带血造血干细胞库应向所在地省级卫生行政部门提交设置可行性研究报告，内容包括：
MYDREAM演讲稿3分钟
my dream good afternoon,ladies and gentlemen.different people have different dreams.whats your dream?could you tell me your dream?of course,now its my tend to share my dream with you. my dream is to do myself well.maybe you will say its so easy that you can do it right away.really? when i was young,i lived by a river.at first,the river was very clean.after several years,the river was covered with lots of rabbish.in my eyes,i felt very sad,removing the gabbage from the river.as we all know,we cant do anything without water,and we will die,then the world will end.why does it occur?thats only because we cant do ourselves well and throw the gabbage everywhere.after that,i dicided to do myself well. however,when i entered senior high school,i lost myself and forgot my dream.as a student,i was supported to study hard,but i indulged myself in surfing the internet.i hadnt even mentioned my dream before my mom asked me with anger whether i would stick to my dream.i felt very guilty ,and still remembered the look of my mom.i must insist on my dream,never give up.im sure i can do myself well. my dream dear teachers and students, good afternoon !today,im very glad to stand here to share my dream with you. everyone has a dream. some people want to be rich,some people want to be famous.different people have different dreams. i have a great dream,too. i love english very much.so i want to be a famous translator in the world.people all over the world can know me . i never thought of my dream when i was a kid. later,my dream always changed. at that time, i dont know what my dream is. i havent studied english at all when i was in primary school. so you can imagine how awful my english is. i think it is impossible for me to study english well. because i never read english words and english articles. i dont like english ,either. and i cant read the english well. but one day something changed , i have that’s all.thanks for listening !篇三：my_dream演讲稿 my dream dear students and teachers: good morning i want to teach others. i want to teach students more knowledge. so i want to be a teacher. being a teacher is my dream. i think it is simple but meaningful . thank you. my dream i dream of being a doctor. home late and tired. she has to go to the hospital immediately any time she is needed, no matter how late it is at night. when i was very little and still in primary school, i once asked her why she chose such a boring and hard job. she answered with a smile, “yes i am sometimes very tired but seeing my patients getting
英语演讲稿《Mydream》(二).doc
dreams and ultimately made them come true. When I was young, I saw a dog one day. I threw a stone at it just for fun. Then it fell down and looked very weak. At that moment, I was surprised to notice it was pregnant. I can’t remember what happened next, but there’s one thing I know: that I felt guilty. It was the first time that I found life could so easily pass away. At that time, I had a dream, which was to help those people who needed help. There are too many wars and disasters. About 16,000 people have died in the Iraq War and one child dies every eight seconds in Africa because of starvation. I have dreams, you have dreams and they have dreams too. We should help them. We should save their lives so that they can pursue their own dreams.
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英语演讲稿mydream
英语演讲稿mydream 篇一：五分钟英语演讲稿__My_dream My dream Dear teachers and students, good afternoon !Today,I'm very glad to stand here to share my dream with you. Everyone has a dream. Some people want to be rich,some people want to be famous.Different people have different dreams. I have a great dream,too. I love English very much.So I want to be a famous translator in the world.People all over the world can know me . I never thought of my dream when I was a kid. Later,my dream always changed. At that time, I don't know what my dream is. I haven't studied English at all when I was in primary school. So you can imagine how awful my English is. I think it is impossible for me to study English well. Because I never read English words and English articles. I don't like English ,either. And I can't read the English well. But one day something changed , I have already changed my mind . I fall in love with
精神分裂症的病因是什么
精神分裂症的病因是什么 精神分裂症是一种精神方面的疾病，青壮年发生的概率高，一般 在16～40岁间，没有正常器官的疾病出现，为一种功能性精神病。 精神分裂症大部分的患者是由于在日常的生活和工作当中受到的压力 过大，而患者没有一个良好的疏导的方式所导致。患者在出现该情况 不仅影响本人的正常社会生活，且对家庭和社会也造成很严重的影响。 精神分裂症常见的致病因素： 1、环境因素：工作环境比如经济水平低低收入人群、无职业的人群中，精神分裂症的患病率明显高于经济水平高的职业人群的患病率。还有实际的生活环境生活中的不如意不开心也会诱发该病。 2、心理因素：生活工作中的不开心不满意，导致情绪上的失控，心里长期受到压抑没有办法和没有正确的途径去发泄，如恋爱失败， 婚姻破裂，学习、工作中不愉快都会成为本病的原因。 3、遗传因素：家族中长辈或者亲属中曾经有过这样的病人，后代会出现精神分裂症的机会比正常人要高。 4、精神影响：人的心里与社会要各个方面都有着不可缺少的联系，对社会环境不适应，自己无法融入到社会中去，自己与社会环境不相
适应，精神和心情就会受到一定的影响，大脑控制着人的精神世界， 有可能促发精神分裂症。 5、身体方面：细菌感染、出现中毒情况、大脑外伤、肿瘤、身体的代谢及营养不良等均可能导致使精神分裂症，身体受到外界环境的 影响受到一定程度的伤害，心里受到打击，无法承受伤害造成的痛苦，可能会出现精神的问题。 对于精神分裂症一定要配合治疗，接受全面正确的治疗，最好的 疗法就是中医疗法加心理疗法。早发现并及时治疗并且科学合理的治疗，不要相信迷信，要去正规的医院接受合理的治疗，接受正确的治 疗按照医生的要求对症下药，配合医生和家人，给病人创造一个良好 的治疗环境，对于该病的康复和痊愈会起到意想不到的效果。
卫生部办公厅关于印发《脐带血造血干细胞治疗技术管理规范(试行)
卫生部办公厅关于印发《脐带血造血干细胞治疗技术管理规 范(试行)》的通知 【法规类别】采供血机构和血液管理 【发文字号】卫办医政发[2009]189号 【失效依据】国家卫生计生委办公厅关于印发造血干细胞移植技术管理规范(2017年版)等15个“限制临床应用”医疗技术管理规范和质量控制指标的通知 【发布部门】卫生部(已撤销) 【发布日期】2009.11.13 【实施日期】2009.11.13 【时效性】失效 【效力级别】部门规范性文件 卫生部办公厅关于印发《脐带血造血干细胞治疗技术管理规范（试行）》的通知 （卫办医政发〔2009〕189号） 各省、自治区、直辖市卫生厅局，新疆生产建设兵团卫生局： 为贯彻落实《医疗技术临床应用管理办法》，做好脐带血造血干细胞治疗技术审核和临床应用管理，保障医疗质量和医疗安全，我部组织制定了《脐带血造血干细胞治疗技术管理规范（试行）》。现印发给你们，请遵照执行。 二〇〇九年十一月十三日
脐带血造血干细胞 治疗技术管理规范（试行） 为规范脐带血造血干细胞治疗技术的临床应用，保证医疗质量和医疗安全，制定本规范。本规范为技术审核机构对医疗机构申请临床应用脐带血造血干细胞治疗技术进行技术审核的依据，是医疗机构及其医师开展脐带血造血干细胞治疗技术的最低要求。 本治疗技术管理规范适用于脐带血造血干细胞移植技术。 一、医疗机构基本要求 （一）开展脐带血造血干细胞治疗技术的医疗机构应当与其功能、任务相适应，有合法脐带血造血干细胞来源。 （二）三级综合医院、血液病医院或儿童医院，具有卫生行政部门核准登记的血液内科或儿科专业诊疗科目。 1.三级综合医院血液内科开展成人脐带血造血干细胞治疗技术的，还应当具备以下条件： （1）近3年内独立开展脐带血造血干细胞和（或）同种异基因造血干细胞移植15例以上。 （2）有4张床位以上的百级层流病房，配备病人呼叫系统、心电监护仪、电动吸引器、供氧设施。 （3）开展儿童脐带血造血干细胞治疗技术的，还应至少有1名具有副主任医师以上专业技术职务任职资格的儿科医师。 2.三级综合医院儿科开展儿童脐带血造血干细胞治疗技术的，还应当具备以下条件：
3分钟英语演讲稿mydream
3分钟英语演讲稿mydream 英语借词的词源很广泛。由于曾受到古代法语的影响，英语词汇在一定程度上大致分为日耳曼词源,以下是小编整理了3分钟英语演讲稿mydream，供你参考。 3分钟英语演讲稿mydream my dream students, guests , teachers and honorable judges good morning ! my great pleasure to share my dream with you today. my dream is to become a teacher.... as the whole world has its boundaries, limits and freedom coeist in our life. i don’t epect complete freedom, which is impossible. i simply have a dream that supports my life. i dream that one day, i could escape from the deep sea of thick schoolbooks and lead my own life. with my favorite fictions, i lie freely on the green grass, smelling the spring, listening to the wind singing, breathing the fresh and cool air and dissolve my soul in nature at last. si-mp-le and short enjoyment can bring me great satisfaction. i dream that one day the adults could throw their prejudice of comic and cartoon away. they could keep a lovely heart that can share sorrow and happinewith us while watching cartoon or doing personal things. that’s the real communication of heart to heart. i have the belief that my dreams should come true. i am looking forward to some day coming when i am like a proud eagle, which flies to the blue and vast sky. Everyone has their own dreams, I am the same. But my dream is not a lawyer, not a doctor, not actors, not even an industry. Perhaps my dream big people
Mydream英语演讲稿范文五篇
Mydream英语演讲稿范文五篇 有人会说：做梦使人进步，我们必须快快长大，才能真正实现荒诞的梦。以下是为大家收集的My dream英语演讲稿范文全部内容了，希望大家会喜欢。如果您喜欢这篇文章，请分享给您的小伙伴们吧!欢迎持续关注我们的后续更新。 My dream is to have robots.In 2345, there are many robots in the world. Every family has more than one robot. Everyone can make different robot, it’s popular in the world. I have three robots, the first one is from my friend, the second one is from my parents, and the third one is from my classmate. The first robot is Peg. It has a square face, its body is a big circle, and it has a small mouth. It can run very fast, it can jump very high, it can swim slowly, and it can fly with me! It likes eating some milk for breakfast, some noodles for lunch and some porridge for dinner. Look! Peg is riding a bicycle. It’s learning about balance. Be careful, Peg!
精神分裂症应该怎么治疗
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懒散、纪律松弛、做事注意力不集中，总是和患病之前的性格完全 相悖。 再者就是语言表达异常，在谈话中说一些无关的谈话内容，使人无法理解。连最简单的话语都无法准确称述，与之谈话完全感觉不 到重心。 第三个就是行为的异常，行为怪异让人无法理解，喜欢独处、不适意的追逐异性，不知廉耻，自语自笑、生活懒散、时常发呆、蒙 头大睡、四处乱跑，夜不归宿等。 还有情感上的变化，失去了以往的热情，开始变的冷淡、对亲人不关心、和友人疏远，对周围事情不感兴趣，一点消失都可大动干戈。 最后就是敏感多疑，对任何事情比较敏感，精神分裂症患者，总认为有人针对自己。甚至有时认为有人要害自己，从而不吃不喝。 但是也有的会出现难以入眠、容易被惊醒或睡眠不深，整晚做恶梦或者长睡不醒的现象。这些都有可能是患上了精神分裂症。 1.加强心理护理 心理护理是家庭护理中的重要方面，由于社会上普遍存在对精神病人的歧视和偏见，给病人造成很大的精神压力，常表现为自卑、 抑郁、绝望等，有的病人会因无法承受压力而自杀。家属应多给予 些爱心和理解，满足其心理需求，尽力消除病人的悲观情绪。病人 生活在家庭中，与亲人朝夕相处，接触密切，家属便于对病人的情感、行为进行细致的观察，病人的思想活动也易于向家属暴露。家 属应掌握适当的心理护理方法，随时对病人进行启发与帮助，启发 病人对病态的认识，帮助他们树立自信，以积极的心态好地回归社会。 2.重视服药的依从性 精神分裂症病人家庭护理的关键就在于要让病人按时按量吃药维持治疗。如果不按时服药，精神病尤其是精神分裂症的复发率很高。精神病人在医院经过一系统的治疗痊愈后，一般需要维持2~3年的
卫生部关于印发《脐带血造血干细胞库设置管理规范(试行)》的通知
卫生部关于印发《脐带血造血干细胞库设置管理规范(试行)》的通知 发文机关：卫生部(已撤销) 发布日期： 2001.01.09 生效日期： 2001.02.01 时效性：现行有效 文号：卫医发(2001)10号 各省、自治区、直辖市卫生厅局： 为贯彻实施《脐带血造血干细胞库管理办法（试行）》，保证脐带血临床使用的安全、有效，我部制定了《脐带血造血干细胞库设计管理规范（试行）》。现印发给你们，请遵照执行。 附件：《脐带血造血干细胞库设置管理规范（试行）》 二○○一年一月九日 附件： 脐带血造血干细胞库设置管理规范（试行） 脐带血造血干细胞库的设置管理必须符合本规范的规定。 一、机构设置 （一）脐带血造血干细胞库（以下简称脐带血库）实行主任负责制。 （二）部门设置 脐带血库设置业务科室至少应涵盖以下功能：脐带血采运、处理、细胞培养、组织配型、微生物、深低温冻存及融化、脐带血档案资料及独立的质量管理部分。 二、人员要求
（一）脐带血库主任应具有医学高级职称。脐带血库可设副主任，应具有临床医学或生物学中、高级职称。 （二）各部门负责人员要求 1．负责脐带血采运的人员应具有医学中专以上学历，2年以上医护工作经验，经专业培训并考核合格者。 2．负责细胞培养、组织配型、微生物、深低温冻存及融化、质量保证的人员应具有医学或相关学科本科以上学历，4年以上专业工作经历，并具有丰富的相关专业技术经验和较高的业务指导水平。 3．负责档案资料的人员应具相关专业中专以上学历，具有计算机基础知识和一定的医学知识，熟悉脐带血库的生产全过程。 4．负责其它业务工作的人员应具有相关专业大学以上学历，熟悉相关业务，具有2年以上相关专业工作经验。 （三）各部门工作人员任职条件 1．脐带血采集人员为经过严格专业培训的护士或助产士职称以上卫生专业技术人员并经考核合格者。 2．脐带血处理技术人员为医学、生物学专业大专以上学历，经培训并考核合格者。 3．脐带血冻存技术人员为大专以上学历、经培训并考核合格者。 4．脐带血库实验室技术人员为相关专业大专以上学历，经培训并考核合格者。 三、建筑和设施 （一）脐带血库建筑选址应保证周围无污染源。 （二）脐带血库建筑设施应符合国家有关规定，总体结构与装修要符合抗震、消防、安全、合理、坚固的要求。 （三）脐带血库要布局合理，建筑面积应达到至少能够储存一万份脐带血的空间；并具有脐带血处理洁净室、深低温冻存室、组织配型室、细菌检测室、病毒检测室、造血干/祖细胞检测室、流式细胞仪室、档案资料室、收/发血室、消毒室等专业房。 （四）业务工作区域应与行政区域分开。
精神分裂症患者在怎样的情况下会自杀
精神分裂症患者在怎样的情况下会自杀 精神分裂症是最常见的一种精神病。早期主要表现为性格改变，如不理采亲人、不讲卫生、对镜子独笑等。病情进一步发展，即表现为思维紊乱，病人的思考过程缺乏逻辑性和连贯性，言语零乱、词不达意。精神分裂症患者随时有可能出现危险行为，这主要是指伤人毁物、自伤自杀和忽然出走。这些危险行为是受特定的精神症状支配的.那么精神分裂症患者在什么情况下会自杀呢？ 被害妄想：这是所有精神病人最常见的症状之一，多数病人采取忍耐、逃避的态度，少数病人也会“先下手为强”，对他的“假想敌”主动攻击。对此，最重要的是弄清病人的妄想对象，即：病人以为是谁要害他。假如病人的妄想对象是某个家里人，则应尽量让这位家属阔别病人，至少不要让他与病人单独在一起。 抑郁情绪：精神分裂症病人在疾病的不同时期，可能出现情绪低落，甚至悲观厌世。特别需要留意的是，有相当一部分自杀成功的病人，是在疾病的恢复期实施自杀行为的。病人在精神病症状消除以后，因自己的病背上了沉重的思想包袱，不能正确对待升学、就业、婚姻等现实问题，感到走投无路，因此选择了轻生。对此，家属一定要防患于未然，要尽早发现病人的心理困扰，及时疏导。 对已经明确表示出自杀观念的病人，家属既不要惊慌失措，也不要躲躲闪闪，要主动与病人讨论自杀的利弊，帮助病人全面、客观地评估现实中碰到的各种困难，找出切实可行的解决办法。 另外，这种病人在自杀之前，是经过周密考虑，并且做了充分预备的，例如写遗书、收拾旧物、向家人离别、选择自杀时间、预备自杀工具等。这类病人的自杀方式也是比较温顺的，多数是服药自杀。因此，他需要一定的时间来积攒足足数目的药物，这时就能看出由家属保管药品的重要性了。只要家属密切观察病人的情绪变化，是不难早期发现病人的自杀企图的。 药源性焦虑：抗精神病药的副作用之一是可能引起病人莫名的焦躁不安、手足无措，并伴有心慌、出汗、恐惧等。这些表现多是发作性的，多数发生在下午到傍晚时分，也有的病人在打长效针以后的2?3天内出现上述表现。这种时间上的规律性，有助于家属判定病人的焦虑情绪是否由于药物所致。病人急于摆脱这种强烈的痛苦，会出现冲动伤人或自伤，这些行为只是为了发泄和解脱，并不以死为终极目的。家属可以在病人发作时，给他服用小剂量的安定类药物，或者在医生的指导下，调整抗精神病药的剂量或品种，这样就可以有效地控制病人的焦虑发作。 极度兴奋：病人的精神症状表现为严重的思维紊乱、言语杂乱无章、行为缺乏目的性，这类病人也可能出现自伤或伤人毁物。由于病人的兴奋躁动是持续性的，家属有充分的思想预备，一般比较轻易防范。家属要保管好家里的刀、剪、火、煤气等危险物品，但最根本的办法，是使用大剂量的、具有强烈镇静作用的药物来控制病人的兴奋。假如在家里护理病人确有困难，则可以强制病人住院治
脐带血间充质干细胞的分离培养和鉴定
脐带血间充质干细胞的分离培养和鉴定 【摘要】目的分离培养脐带血间充质干细胞并检测其生物学特性。方法在无菌条件下用密度梯度离心的方法获得脐血单个核细胞，接种含10%胎牛血清的DMEM培养基中。单个核细胞行贴壁培养后，进行细胞形态学观察，绘制细胞生长曲线，分析细胞周期，检测细胞表面抗原。结果采用Percoll(1.073 g/mL)分离的脐血间充质干细胞大小较为均匀，梭形或星形的成纤维细胞样细胞。细胞生长曲线测定表明接后第5天细胞进入指数增生期，至第9天后数量减少;流式细胞检测表明50%～70%细胞为CD29和CD45阳性。结论体外分离培养脐血间充质干细胞生长稳定，可作为组织工程的种子细胞。 【关键词】脐血;间充质干细胞;细胞周期;免疫细胞化学 Abstract: Objective Isolation and cultivation of mesenchymal stem cells (MSCs) in human umbilical cord in vitro, and determine their biological properties. Methods The mononuclear cells were isolated by density gradient centrifugation from human umbilical cord blood in sterile condition, and cultured in DMEM medium containing 10% fetal bovine serum. After the adherent mononuclear cells were obtained, the shape of cells were observed by microscope, then the cell growth curve, the cell cycle and the cell surface antigens were obtained by immunocytochemistry and flow cytometry methods. Results MSCs obtained by Percoll (1.073 g/mL) were similar in size, spindle-shaped or star-shaped fibroblasts-liked cells. Cell growth curve analysis indicated that MSCs were in the exponential stage after 5d and in the stationary stages after 9d. Flow cytometry analysis showed that the CD29 and CD44 positive cells were about 50%～70%. Conclusions The human umbilical cord derived mesenchymal stem cells were grown stably in vitro and can be used as the seed-cells in tissue engineering. Key words:human umbilical cord blood; mesenchymal stem cells; cell cycle; immunocytochemistry 间充质干细胞(mesenchymal stem cells，MSCs)在一定条件下具有多向分化的潜能，是组织工程研究中重要的种子细胞来源。寻找来源丰富并不受伦理学制约的间充质干细胞成为近年来的研究热点[1]。脐血(umbilical cord blood, UCB)在胚胎娩出后，与胎盘一起存在的医疗废物。与骨髓相比，UCB来源更丰富，取材方便，具有肿瘤和微生物污染机会少等优点。有人认为脐血中也存在间充质干细胞(Umbilical cord blood-derived mesenchymal stem cells，UCB-MSCs)。如果从脐血中培养出MSCs，与胚胎干细胞相比，应用和研究则不受伦理的制约，蕴藏着巨大的临床应用价值[2,3]。本研究将探讨人UCB-MSCs体外培养的方法、细胞的生长曲线、增殖周期和细胞表面标志等方面，分析UCB-MSCs 作为间充质干细胞来源的可行性。