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1.
目的 研究小窝蛋白-1反义寡核苷酸(cav1-AS ODN)在血管加压素(AVP)诱导的成年大鼠心肌成纤维细胞(CFs)增殖erk1/2信号转导中的作用及辛伐他汀(Sim)对cav1表达的干预效应.方法 采用脂质体导入法将cav1-AS ODN导入离体培养的成年大鼠CFs,用3H-TdR掺入法定量观察CFs增殖,蛋白免疫印迹法分析cav1-AS ODN对AVP诱导大鼠CFs增殖后磷酸化erk1/2 (p-erk1/2)、p21和细胞周期蛋白A(cyclin A)表达变化及Sim对cav1表达的影响.结果 cav1-AS ODN与10-7 mol/L的AVP共同干预组,大鼠CFs内3H-TdR掺入率和p-erk1/2蛋白表达量分别相当于空白对照组的(212±6)% 和(7.9 ± 0.3)%,10-7mol/L的AVP单独干预组的3H-TdR掺入率和p-erk1/2表达量分别相当于空白对照组的(172±4)%和(5.7±0.2)%,两组比较差异非常显著(P<0.01).cav1-AS ODN单独干预或与10-7mol/L的AVP共同干预大鼠CFs 24 h后,两组CFs内p21表达丰度均较空白对照组下降,cyclin A表达丰度升高.β-环糊精、黄体酮或Sim可减少CFs胞膜上cav1蛋白表达.用10、15或20 μg/ml胆固醇分别与10-7 mol/L Sim共同干预CFs 24 h后,CFs胞膜上cav1蛋白表达量分别相当于对照组的(86±3)%、(91±4)%和(94±5)%,与10-7mol/L Sim单独作用CFs组(66±4)%比较,均有显著的统计学差异(P<0.05,P<0.01).结论 cav1-AS ODN可增强AVP促CFs增殖的作用,Sim降胆固醇作用影响CFs胞膜上cav1蛋白表达,从而影响CFs增殖.  相似文献   

2.
目的观察卡维地洛(carvedilol)、比索洛尔(bisoprolol)、哌唑嗪(prazosin)对培养的SHR和Wistar大鼠心肌成纤维细胞(CFs)增殖的影响.方法采用胰酶消化法培养CFs,用 3H-TdR法、MTT比色法分别观察carvedilol、bisolol、prazosin干预下CFs的增殖情况.结果 SHR、Wistar大鼠CFs 3H-TdR掺入及OD值随carvedilol浓度的增加而减低,呈剂量和时间依赖性.10-5 mol /L carvedilol分别干预SHR和Wistar大鼠CFs 72 h其 3H-TdR掺入分别减低52.1%和47.5%,OD值分别减低41.5% 和 35.3%, bisolol(10-8 mol/L~10-5mol/L )和prazosin(10-8 mol/L~10-5 mol/L)则无此作用.结论 Carvedilol抑制心肌成纤维细胞增殖,并呈浓度及时间依赖性,高血压时,CFs对Carvedilol更为敏感.而Bisoprolol和Prazosin则对CFs细胞增殖无影响.  相似文献   

3.
目的探讨V1受体拮抗剂[d(CH2)5-Tyr2(Me)]AVP对精氨酸升压素(AVP)诱导的大鼠心脏成纤维细胞增殖的影响. 方法采用胰酶消化法培养新生Sprague-Dawley (SD)大鼠心脏成纤维细胞(CFs),以3H-TdR掺入法测定CFs的DNA合成功能,MTT比色法测定CFs数目,并应用流式细胞仪进行CFs细胞周期分析. 结果①CFs的3H-TdR掺入率随着AVP干预浓度的增加而增高,其中10-7mol/L AVP和10-6mol/L AVP组每5000个细胞的3H-TdR掺入率分别为(243±61)cpm和(328±68)cpm,均明显高于对照组3H-TdR掺入率(117±32)cpm(P<0.01);②MTT比色法吸光度(A490 nm)值随AVP浓度的增加而增高,其中10-7mol/L AVP、10-6mol/L AVP组的A490 nm值分别为0.24±0.01和0.29±0.02,均较对照组A490 nm值(0.16±0.01)显著增高(P<0.01);③10-7mol/L AVP组CFs细胞周期S期百分率显著高于对照组(30.20±0.88)% vs (26.86±1.06)%( P<0.01);④10-7mol/L AVP+10-7 mol/L [d(CH2)5-Tyr2(Me)]AVP组的每5000个细胞的3H-TdR掺入率、MTT比色法A490 nm值和S期百分率分别为(143±40)cpm、0.17±0.01和(25.02±0.51)%,均显著低于10-7mol/L AVP组(分别P<0.05,P<0.01,P<0.01). 结论 AVP可诱导CFs的DNA合成功能增强和细胞数目增加,其作用可被V1受体拮抗剂[d(CH2)5-Tyr2(Me)] AVP所阻断,表明V1受体可能介导了AVP促CFs增殖效应.  相似文献   

4.
目的:探讨醛固酮诱导心肌成纤维细胞(CFs)增殖的信号转导机制.方法:用胰酶消化法分离、培养新生大鼠CFs,采用3H-胸腺嘧啶核苷(3H-TdR)掺入法、western-blotting技术从DNA合成、蛋白表达等方面观察MAPK活化与醛固酮促CFs增殖的关系.结果:①醛固酮剂量依赖性促CFs DNA合成,10-5mol/L PD98059 [(782±152)个·min-1] 可逆转 10-7mol/L醛固酮 [(1879±169)个·min-1]的作用;②10-7mol/L醛固酮对活化MAPK蛋白表达有显著增强作用,在4 h达峰作用(8.11±0.46),10-7mol/L 醛固酮的作用(8.11±0.46)被10-5mol/L PD98059 (1.21±0.10, P<0.01)阻断.结论:醛固酮能激活CFs的MAPK,MAPK表达及活化参与醛固酮诱导的CFs增殖.  相似文献   

5.
血管紧张素Ⅱ刺激肝星状细胞核酸、蛋白质及胶原合成   总被引:7,自引:2,他引:7  
目的 研究不同浓度血管紧张素Ⅱ(AngⅡ)对大鼠肝星状细胞(HSC)增殖和胶原合成的影响。方法 采用酶法分离大鼠肝星状细胞(HSC),应用^3H-TdR(胸腺嘧啶核苷)、^3H-Leu(亮氨酸)、^3H-Pro(脯氨酸)掺入检测10^-9-10^-5mol/L不同浓度AngⅡ对HSC的DNA、蛋白质及脯氨酸合成的影响。结果 10^-9-10^-6mol/L AngⅡ能促进HSC对^3H-TdR的掺入率(P<0.05),但只有10^-6mol/L和10^-7mol/L浓度的AngⅡ才能显著增加HSC对^3H-Leu的掺入率(P<0.01);而10^-9-10^-6mol/L AngⅡ均能促进HSC对^3H-Pro的掺入率(P<0.05),且呈剂量依赖关系。结论 适当浓度的AngⅡ能促进HSC增殖和胶原合成。  相似文献   

6.
目的研究白细胞介素10(IL-10)对血管升压素(AVP)诱导大鼠心脏成纤维细胞(CFs)增殖及Ⅰ、Ⅲ型胶原合成的影响。方法以培养的新生SD大鼠CFs为实验模型,四氮唑盐(MTT)比色法检测CFs增殖,流式细胞仪技术(FCM)测定细胞周期,逆转录聚合酶链式反应(RT-PCR)检测Ⅰ、Ⅲ型胶原mRNA表达水平。结果(1)10-7mol/L AVP作用24h,CFs的吸光度(A490)为0·216±0·013,较对照组(0·132±0·006)显著增加(P<0·01)。(2)IL-10呈浓度依赖性下调AVP诱导的CFs的A490的增加,其10-8g/mLIL-10干预组CFs的A490(0·157±0·029)较AVP组显著降低(P<0·01)。(3)AVP组CFs的S期百分率及增殖指数(12·30±0·71,19·58±0·88)较对照组(4·22±0·48,7·12±0·62)显著增加(P<0·01);而10-9g/mLIL-10干预组,CFs的S期百分率及增殖指数(9·56±1·13,13·86±1·28)较AVP组显著降低(P<0·01)。(4)AVP组Ⅰ、Ⅲ型胶原mRNA表达水平(1·45±0·06,1·06±0·06)较对照组(1·03±0·05,0·77±0·05)显著增加(P<0·01)。而IL-10可浓度依赖性的下调AVP诱导的CFs的Ⅰ、Ⅲ型胶原mRNA表达,其10-8g/mL IL-10干预组Ⅰ、Ⅲ型胶原mRNA表达水平(1·14±0·06,0·88±0·02)显著低于AVP组(P<0·01)。结论IL-10具有抑制AVP诱导CFs增殖和胶原合成的作用,这可能对预防和逆转心脏重构有一定的价值。  相似文献   

7.
目的:探讨β1整合素反义寡核苷酸(ASODN)对精氨酸加压素(AVP)诱导大鼠心脏成纤维细胞(CFs)DNA合成功能的抑制作用。方法:以胰蛋白酶消化法分离、培养SD大鼠的CFs,采用MTT吸光度法及3H-胸腺嘧啶核苷(3H-TdR)掺入法,原位酶联免疫吸附测定(ELISA)等技术,观察基础状态下β1整合素ASODN对CFs细胞数目及DNA合成功能的影响;β1整合素ASODN对AVP诱导的β1整合素表达,CFs增殖及DNA合成功能的影响;基础状态下设空白对照组、反义链组和正义链组;AVP诱导下设空白对照组、1×10-7mol/L AVP组、反义链+1×10-7mol/L AVP组和正义链+1×10-7mol/L AVP组,每组均为8个复孔。结果:①反义链组的CFs细胞数目及3H-TdR掺入率明显低于空白对照组及正义链组,并且均有统计学意义(P0.01);正义链组与对照组比较无统计学意义。②1×10-7mol/LAVP组和正义链+1×10-7mol/LAVP组的β1整合素表达水平,CFs细胞数目均高于空白对照组(P0.05),β1整合素ASODN与AVP共同作用组的β1整合素表达水平,CFs细胞数目明显低于1×10-7mol/LAVP组和正义链+1×10-7mol/L AVP组,并且均有非常显著性意义(P0.01)。③1×10-7mol/L AVP组和正义链+1×10-7mol/L AVP组的CFs3H-TdR掺入率均高于空白对照组(P0.05),β1整合素ASODN与AVP共同作用组的CFs3H-TdR掺入率明显低于空白对照组、1×10-7mol/L AVP组和正义链+1×10-7mol/L AVP组,并且均有非常显著性意义(P0.01)。结论:β1整合素ASODN不但抑制基础状态下CFs生长及DNA合成代谢,而且抑制AVP刺激β1整合素表达、CFs增殖、DNA合成的作用,说明针对特异性靶基因片段合成的ASODN可能抑制β1整合素遗传信息传递的某个环节,干扰细胞内外信息的传递,影响β1整合素介导的CFs与细胞外基质的黏附,从而产生拮抗AVP刺激心脏间质重构形成的作用。进一步提示应用反义药物防治高血压心脏间质重构的可能性。  相似文献   

8.
目的:探讨精氨酸加压素(AVP)及其V1a受体对体外培养的SD仔鼠心肌成纤维细胞(CFs)向肌成纤维细胞(MFs)转化的影响。方法:胰酶消化法分离培养SD仔鼠CFs,将CFs分别与不同浓度(10-9、10-8、10-7、10-6 mmol/L)AVP,或添加了不同浓度(0、10-9、10-8、10-7 mmol/L)AVP V1a特异性受体拮抗剂[d(CH2)5Tyr2(Me)]AVP的10-6 mmol/L AVP共同孵育48h后,用3 H-脯氨酸掺入法检测CFs胶原合成功能,Western blot检测CFs平滑肌肌动蛋白α(α-SMA)表达量,α-SMA免疫荧光染色观察CFs形态。结果:AVP浓度依赖性地诱导CFs的3 H-脯氨酸掺入率和α-SMA表达量增加,其中10-6 mmol/L AVP组CFs的3 H-脯氨酸掺入率和α-SMA表达量均显著高于对照组(均P<0.05),且10-6 mmol/L AVP作用下CFs体积明显增大,胞质荧光染色亮度显著增强,胞质中有明显的张力丝样结构。而[d(CH2)5Tyr2(Me)]AVP可以浓度依赖性地抑制10-6 mmol/L AVP诱导下CFs 3 H-脯氨酸掺入率和α-SMA表达量的增加,其中10-8、10-7 mmol/L[d(CH2)5Tyr2(Me)]AVP组中CFs的3 H-脯氨酸掺入率显著低于10-6 mmol/L AVP组(均P<0.05),10-9、10-8、10-7 mmol/L[d(CH2)5Tyr2(Me)]AVP组中CFs的α-SMA表达量显著低于10-6 mmol/L AVP组(均P<0.05),且10-7 mmol/L[d(CH2)5Tyr2(Me)]AVP能够将10-6 mmol/L AVP诱导下CFs的3 H-脯氨酸掺入率、α-SMA表达量和形态学变化都抑制到对照组水平(均P>0.05)。结论:AVP通过其V1a受体诱导CFs向MFs转化。  相似文献   

9.
目的 观察卡维地洛(carvedilol)、比索洛尔(bisoprolol)、哌唑嗪(prazosin)对培养的SHR和Wistar大鼠心肌成纤维细胞(CFs)增殖的影响。方法 采用胰酶消化法培养CFs,用^3H—TdR法、MTT比色法分别观察carvedilol、bisolol、prazosin干预下CFs的增殖情况。结果 SHR、Wistar大鼠CFs^3H-TdR掺入及OD值随carvedilol浓度的增加而减低,呈剂量和时间依赖性。10^-5mo1/L carvedilol分别干预SHR和Wistar大鼠CFs72h其h其^H-TdR掺入分别减低52.1%和47.5%,OD值分别减低41.5%和35.3%,bisolol(10^-8mo1/L一10^-5mol/L)和przosin(10^-8mol/L一10^-5mol/L)则无此作用。结论 Carvedilol抑制心肌成纤维细胞增殖,并呈浓度及时间依赖性,高血压时,CFs对Carvedilol更为敏感。而Bisoprolol和Prazosin则对CFs细胞增殖无影响。  相似文献   

10.
目的:探讨洛伐他汀对醛固酮诱导心肌成纤维细胞( CFs)增殖及诱导型一氧化氮合酶-一氧化氮( iN-OS-NO)系统活性的调控作用。方法用胰酶消化法分离、培养新生SD大鼠CFs,采用MTT比色法、硝酸还原酶法、分光光度法和半定量RT-PCR技术,观察不同浓度洛伐他汀对CFs增殖、NO含量、iNOS活性和iNOS mRNA表达的影响。结果洛伐他汀(1×10-8~1×10-5 mol/L)能剂量依赖性抑制醛固酮诱导CFs的增殖,升高CFs的NO含量、iNOS活性及增加iNOS mRNA的表达(P均<0.05),甲羟戊酸(1×10-3 mol/L)、法尼酯焦磷酸(5μmol/L)可完全逆转洛伐他汀的上调作用。洛伐他汀干预下醛固酮诱导CFs的NO生成量与iNOS活性、iNOS活性与iNOS mRNA表达均呈正相关(r分别为0.826、0.752,P均<0.01);CFs增殖数目与NO含量呈负相关(r=-0.908,P<0.01)。结论洛伐他汀可上调醛固酮诱导CFs的iNOS-NO系统活性,抑制CFs增殖,并呈剂量依赖性,其作用机制可能与甲羟戊酸途径调节有关。  相似文献   

11.
目的胰岛素瘤是最常见的胰腺神经内分泌肿瘤,因其临床表现多样,导致诊断困难。影像学诊断尤其是超声内镜(EUS)在胰岛素瘤的诊断中起着重要作用,拥有较高的敏感性和特异性。本研究拟通过明确胰岛素瘤的解剖分布特点,以期有助于提高影像学的诊断准确率和降低漏诊率,尤其是在教育和培训实践中对于EUS的学习者更具有指导价值。 方法回顾性分析解放军总医院第一医学中心病案资料数据库1993年1月至2019年11月经外科手术、病理确诊为胰岛素瘤的患者的临床资料,检索方法采取搜索术后病理诊断为"胰岛素瘤"的病例,通过查阅病例的方法,提取出胰岛素瘤的大小和解剖分布等数据,进一步分析其特点。 结果共检索到确诊为胰岛素瘤的患者116例,其中,男45例、女71例,年龄13~76岁,平均年龄(44.4±14.85)岁。胰岛素瘤单发110例(94.8%)、多发6例(5.2%)。位置分布:头颈部46例(39.7%),单发45例、多发1例;体尾部68例(58.6%),单发65例、多发3例;全胰腺多发2例(1.7%)。病变大小特点:最大径0.4~3.4 cm,平均大小(1.53±0.58)cm。≤1 cm 29例、>1 cm而≤1.5 cm41例、>1.5 cm而≤2.0 cm28例,≤3 cm 15例,>3 cm 3例。年龄与肿瘤的大小相关,≤44岁患者肿瘤平均大小为(1.36±0.51)cm、>44岁患者肿瘤平均大小为(1.70±0.60)cm,P<0.05。头颈部的肿瘤大于体尾部的肿瘤,头颈部肿瘤平均大小(1.66±0.63)cm,体尾部(1.42±0.52)cm,P<0.05。 结论胰岛素瘤在胰腺体尾部较头颈部更好发;绝大多数单发,但可以全胰腺多发;多数小于1.5 cm,肿瘤的大小与患者年龄和肿瘤的解剖分布相关。  相似文献   

12.
Most adenomas and carcinomas of the small intestine and extrahepatic bile ducts arise in the region of the papilla of Vater. In familial adenomatous polyposis (FAP) it is the main location for carcinomas after proctocolectomy. In many cases symptoms due to stenosis lead to diagnosis at an early tumor stage. In about 80%, curative intended resection is possible. Operability is the most relevant prognostic factor. Most ampullary carcinomas resp. carcinomas of the papilla of Vater develop from adenomatous or flat dysplastic precursor lesions. They can be sited in the ampulloduodenal part of the papilla of Vater, which is lined by intestinal mucosa. They also can develop in deeper parts of the ampulla, which are lined by pancreaticobiliary duct mucosa. Intestinal-type adenocarcinoma and pancreaticobiliary-type adenocarcinoma represent the main histological types of ampullary carcinoma. Furthermore, there exist unusual types and undifferentiated carcinomas. Many carcinomas of intestinal type express the immunohistochemical marker profile of intestinal mucosa (keratin 7?, keratin 20+, MUC2+). Carcinomas of pancreaticobiliary type usually show the immunohistochemical profile of pancreaticobiliary duct mucosa (keratin 7+, keratin 20?, MUC2?). Even poorly differentiated carcinomas, as well as unusual histological types, may conserve the marker profile of the mucosa they developed from. These findings underline the concept of histogenetically different carcinomas of the papilla of Vater which develop either from intestinal- or from pancreaticobiliary-type mucosa of the papilla of Vater. Molecular alterations in ampullary carcinomas are similar to those of colorectal as well as pancreatic carcinomas, although they appear at different frequencies. In future studies, molecular alterations in ampullary carcinomas should be correlated closely with the different histologic tumor types. Consequently, the histologic classification should reflect the histogenesis of ampullary tumors from the two different types of papillary mucosa.  相似文献   

13.
Summary Palmitic acid oxidation in rat diaphragm homogenate is depressed by biguanide concentrations that are still incapable of inhibiting oxidative phosphorylation. Glucose oxidation is not directly effected by the same biguanide concentrations: however, the inhibitory effect of palmitic acid on glucose oxidation is partly removed by biguanides. Inhibition of fatty acid oxidation, which accounts for most of the metabolic effects caused by these drugs, can be regarded as the fundamental mechanism of action of biguanides. There is some evidence suggesting that these drugs might interact with carnitine, thus preventing long-chain fatty acids from being transported across the mitochondrial membrane to the site of oxidation. Traduzione a cura degli AA.  相似文献   

14.
BACKGROUND AND AIM: Both the clinical presentation and the degree of mucosal damage in coeliac disease vary greatly. In view of conflicting information as to whether the mode of presentation correlates with the degree of villous atrophy, we reviewed a large cohort of patients with coeliac disease. PATIENTS AND METHODS: We correlated mode of presentation (classical, diarrhoea predominant or atypical/silent) with histology of duodenal biopsies and examined their trends over time. RESULTS: The cohort consisted of 499 adults, mean age 44.1 years, 68% females. The majority had silent coeliac disease (56%) and total villous atrophy (65%). There was no correlation of mode of presentation with the degree of villous atrophy (p=0.25). Sixty-eight percent of females and 58% of males had a severe villous atrophy (p=0.052). There was a significant trend over time for a greater proportion of patients presenting as atypical/silent coeliac disease and having partial villous atrophy, though the majority still had total villous atrophy. CONCLUSIONS: Among our patients the degree of villous atrophy in duodenal biopsies did not correlate with the mode of presentation, indicating that factors other than the degree of villous atrophy must account for diarrhoea in coeliac disease.  相似文献   

15.
血吸虫童虫是宿主免疫系统攻击的重要靶标,包括皮肤型、肺型和肝门型童虫。宿主分子对童虫生长发育具有重要作用。童虫生长发育机制包括免疫调节、信号转导、性别发育及凋亡等。肌动蛋白、组织蛋白酶、烯醇化酶和葡萄糖基转移酶等分子为血吸虫童虫生长发育的重要分子。本文对血吸虫童虫生长发育及其机制的研究进展做一综述。  相似文献   

16.
目的对临床分离的耐多药结核分枝杆菌相关基因的突变特征进行分析。方法对124例耐多药结核分枝杆菌以及50株敏感株的耐药相关基因(包括异烟肼inh A、kat G、oxyR-ahp C间隔区以及利福平rpo B)进行序列测定,分析其基因突变情况。结果异烟肼耐药inh A基因突变率为14.5%;kat G基因突变率为70.2%(87/124),主要位于315位;oxyR-ahp C间隔区突变率为15.3%;inh A、kat G两种基因同时突变率75.0%,三种基因同时突变率为89.5%。利福平rpo B基因突变的检出率高达95.2%,突变主要发生在531、526、516位点。结论我省耐多药菌异烟肼耐药相关基因最常见突变为kat G 315、inh A C-T(-15)、axyR-ahp C间隔区(-10)C-T,利福平为rpo B531、526、516。结合MDR-TB耐药相关基因的特征分析,可以建立一种快速、准确、特异的适合于我省的检测结核菌耐多药性的新方法。  相似文献   

17.
氯硝柳胺悬浮剂的毒性评价   总被引:2,自引:2,他引:2  
目的评价氯硝柳胺悬浮剂的毒性,为现场大规模应用灭螺提供依据。方法按照中华人民共和国国家标准GB 15670-1995《农药登记毒理学试验方法》和鱼类毒性试验方法进行。结果经口、经皮肤的LDso雌、雄性大鼠均>5 000 mg/kg,经呼吸道的LCso雌、雄性大鼠均>5 000mg/m3,该药经口、经皮肤、经呼吸道毒性均属微毒类药物;兔眼用药后,观察期内无不良反应,对眼无刺激性;皮肤用药后对皮肤无刺激性。与氯硝柳胺原药、氯硝柳胺乙醇胺盐原药和氯硝柳胺乙醇胺盐可湿性粉剂相比,氯硝柳胺悬浮剂对鱼急性毒性最低。结论氯硝柳胺悬浮剂属微毒类药物,对鱼的毒性低于其乙醇胺盐可湿性粉剂,适合于现场应用。  相似文献   

18.
The aim of the study was to assess the quality of life (QOL) and the psychological status of parents of children with juvenile chronic arthritis (JCA). The QOL, anxiety and depression of the parents of 28 children with JCA were evaluated and compared to those of the parents of 28 healthy children. Mothers of JCA children and mothers of healthy children reported similar QOL. The reported anxiety and depression levels were similar for mothers and fathers in both groups. The parents of children with pauciarticular-type JCA reported lower QOL and higher levels of anxiety and depression than the parents of children with other types, namely polyarticular and systemic JCA. These findings may be explained by the fact that the pauciarticular patients had shorter disease duration and were less frequently seen in the outpatient clinic. The QOL of mothers of children with JCA was found to be slightly impaired in the group of children with pauciarticular JCA. Future larger studies are needed to confirm these results, as the number of subjects in the three groups was rather low. Received: 26 September 2001 / Accepted: 8 February 2002  相似文献   

19.

Background

A 5-day in-patient study designed to assess the accuracy of the FreeStyle Navigator® Continuous Glucose Monitoring System revealed that the level of accuracy of the continuous sensor measurements was dependent on the rate of glucose change. When the absolute rate of change was less than 1 mg•dl−1•min−1 (75% of the time), the median absolute relative difference (ARD) was 8.5%, with 85% of all points falling within the A zone of the Clarke error grid. When the absolute rate of change was greater than 2 mg•dl−1•min−1 (8% of the time), the median ARD was 17.5%, with 59% of all points falling within the Clarke A zone.

Method

Numerical simulations were performed to investigate effects of the rate of change of glucose on sensor measurement error. This approach enabled physiologically relevant distributions of glucose values to be reordered to explore the effect of different glucose rate-of-change distributions on apparent sensor accuracy.

Results

The physiological lag between blood and interstitial fluid glucose levels is sufficient to account for the observed difference in sensor accuracy between periods of stable glucose and periods of rapidly changing glucose.

Conclusions

The role of physiological lag on the apparent decrease in sensor accuracy at high glucose rates of change has implications for clinical study design, regulatory review of continuous glucose sensors, and development of performance standards for this new technology. This work demonstrates the difficulty in comparing accuracy measures between different clinical studies and highlights the need for studies to include both relevant glucose distributions and relevant glucose rate-of-change distributions.  相似文献   

20.
Angiography using Prostaglandin El® was performed on 38 patients with carcinoma of the colon in order to diagnose the degree of serosal cancer invasion. The findings at angiography were classified into four groups:1) AG-S3, abnormal change (irregularity and/or encasement) up to marginal vessels; 2) AG-S2, abnormality up to vasa recta; 3) AG-S1, abnormality of penetrating branches of vasa recta within the wall of the colon; and 4) AG-S0, no distinct findings of abovementioned vessels. These angiographic findings were compared with both macroscopic and microscopic serosal cancer invasion. Angiographic diagnosis is in accord with the macroscopic findings in 84.2 percent of cases. Angiographic diagnosis is in accord with the microscopic findings in 32.4 percent of cases. Macroscopic findings confirm the angiographic diagnosis precisely but the conflict with microscopic findings should not be overlooked. This may be the result of inflammatory change, adhesion, and fibrosis around carcinoma of the colon.  相似文献   

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