心肌成纤维细胞NOS-NO系统活性的变化及其与AVP的关系

目的 :探讨无干预和血管升压素 （AVP）干预条件下 ,心肌成纤维细胞 （CFs）的一氧化氮合酶—氧化氮 （NOS-NO）系统活性的变化。方法 :胰酶消化法分离、培养新生 SD大鼠 CFs,采用硝酸还原酶法和分光光度法观察无干预和 AVP干预条件下 ,不同培养时间对 CFs的 NOS- NO系统活性的影响。结果 :1无干预条件下 ,CFs的 NO含量和 NOS活性随培养时间延长而增高 ,其中 36 h（4 2± 5 μmol· L- 1 ,37± 5 U· m L- 1 ）显著高于 6 h（14± 3μmol·L- 1 ,10± 4U· m L- 1 ）以及 12 h（2 1± 3μm ol· L- 1 ,15± 3U· m L- 1 ） （均 P<0 .0 5 ）。 2 AVP干预条件下 ,CFs的NO含量和 NOS活性也随培养时间延长而增高 ,其中 2 4h（6 5± 6 μmol· L- 1 ,70± 4U· m L- 1 ） ,36 h（6 2± 1μm ol· L- 1 ,6 9± 6 U· m L- 1 ）都显著高于 6 h （34± 4μmol· L- 1 ,36 +2 U· m L- 1 ）以及 12 h的 （4 5± 4μmol· L- 1 ,45± 1U· m L- 1 ） （均 P<0 .0 5 ）。 3AVP干预条件下 CFs的 NO含量和 NOS活性均较无干预条件下显著增高 ,且 NO含量随 NOS活性增高而增高 ,二者呈显著正相关 （无干预条件下 r=0 .837,P<0 .0 1;AVP干预条件下 r=0 .936 ,P<0 .0 1）。结论 :AVP提高 CFs的 NOS- NO系统活性 ,CFs的 NOS- NO系统活性与培养和 AVP?     

高血压病患者压力感受器敏感性

目的探讨高血压病患者压力感受器敏感性(BRS)情况及其可能影响因素.方法用全自动生化仪测定血脂、血糖,用倾斜方法同时记录血压和心率,BRS=(最低血压时R-R间期-基础R-R间期)/(最低血压-基础血压),用袖带对肱动脉加压后放气,测定肱动脉内径变化率的方法代表血流介导的内皮舒张功能.结果(1)高血压病患者的BRS明显小于正常对照组[(6.9±7.3 vs 13.9±3.6)ms/mm Hg,P＜0.01],亦明显小于肾性高血压组[(6.9±7.3 vs 12.2±6.2)ms/mm Hg,P＜0.01];高血压病BRS有随着高血压分级增高而下降趋势,1级患者BRS大于3级患者[(10.2±4.0 vs 5.4±4.8)ms/mm Hg,P＜0.01],2级患者BRS大于3级患者[(7.6±2.4 vs 5.4±4.8)ms/mm Hg,P＜0.01];(2)高血压病伴高脂血症患者BRS小于高血压病不伴高脂血症组[(2.2±4.7 vs 7.2±6.4)ms/mm Hg,P＜0.01];(3)高血压病患者血管内皮舒张功能与BRS相关(r=0.565,P＜0.01),肾性高血压组内皮舒张功能与BRS相关(r=0.573,P＜0.05),正常对照组内皮舒张功能与BRS相关(r=0.610,P＜0.05).结论(1)BRS功能降低可能是高血压病发病原因之一;(2)降脂治疗可通过升高BRS,改善高血压病患者的预后;(3)血管内皮舒张功能与BRS有关,可通过改善血管内皮舒张功能改善BRS.     

Murine study of portal hypertension associated endothelin-1 hypo-response

AIM:To investigate endothelin-1 hypo-responsive associated with portal hypertension in order to improve patient treatment outcomes.METHODS:Wild type,e NOS-/-and i NOS-/-mice receivedpartial portal vein ligation surgery to induce portal hypertension or sham surgery.Development of portal hypertension was determined by measuring the splenic pulp pressure,abdominal aortic flow and portal systemic shunting.To measure splenic pulp pressure,a microtip pressure transducer was inserted into the spleen pulp.Abdominal aortic flow was measured by placing an ultrasonic Doppler flow probe around the abdominal aorta between the diaphragm and celiac artery.Portal systemic shunting was calculated by injection of fluorescent microspheres in to the splenic vein and determining the percentage accumulation of spheres in liver and pulmonary beds.Endothelin-1 hypo-response was evaluated by measuring the change in abdominal aortic flow in response to endothelin-1 intravenous administration.In addition,thoracic aorta endothelin-1contraction was measured in 5 mm isolated thoracic aorta rings ex-vivo using an ADI small vessel myograph.RESULTS:In wild type and i NOS-/-mice splenic pulp pressure increased from 7.5±1.1 mm Hg and 7.2±1 mm Hg to 25.4±3.1 mm Hg and 22±4 mm Hg respectively.In e NOS-/-mice splenic pulp pressure was increased after 1 d(P=NS),after which it decreased and by 7 d was not significantly elevated when compared to 7 d sham operated controls(6.9±0.6 mm Hg and 7.3±0.8 mm Hg respectively,P=0.3).Abdominal aortic flow was increased by 80%and 73%in 7 d portal vein ligated wild type and i NOS when compared to shams,whereas there was no significant difference in 7 d portal vein ligated e NOS-/-mice when compared to shams.Endothelin-1 induced a rapid reduction in abdominal aortic blood flow in wild type,e NOS-/-and i NOS-/-sham mice(50%±8%,73%±9%and 47%±9%respectively).Following portal vein ligation endothelin-1 reduction in blood flow was significantly diminished in each mouse group.Abdominal aortic flow was reduced by 19%±9%,32%±10%and 9%±9%in wild type,e NOS-/-and i NOS-/-mice respectively.CONCLUSION:Aberrant endothelin-1 response in murine portal hypertension is NOS isoform independent.Moreover,portal hypertension in the portal vein ligation model is independent of ET-1 function.     

老年综合评估在老年高血压患者综合治疗中的应用

目的研究老年综合评估在老年高血压患者综合治疗中的应用。方法选取122例老年原发性高血压患者,随机分为试验组61例和对照组61例。试验组在口服降压药物治疗的同时进行老年综合评估,并依据评估结果实施相应干预措施。观察2组治疗前和治疗后的血压变化情况,并进行分析。结果试验组和对照组治疗后偶侧收缩压/舒张压均较治疗前降低[(132. 72±10. 53)/(69. 28±6. 49) mm Hg(1 mm Hg=0. 133 k Pa) vs (165. 54±9. 28)/(82. 46±8. 87) mm Hg,(147. 21±8. 85)/(69. 61±4. 63) mm Hg vs (164. 26±8. 99)/(81. 92±9. 74) mm Hg,P 0. 01];试验组偶测收缩压较对照组下降更明显(P 0. 01)。试验组和对照组治疗后24 h收缩压/舒张压较治疗前降低[(131. 57±10. 14)/(69. 05±6. 04) mm Hg vs (161. 33±10. 10)/(80. 84±7. 86) mm Hg,(144. 30±8. 69)/(70. 51±4. 88) mm Hg vs (161. 28±8. 92)/(80. 10±7. 73) mm Hg,P 0. 01];试验组24 h收缩压较对照组下降更明显(P 0. 01)。2组治疗后的血压变异性均较治疗前明显降低,且试验组降低更为明显(P 0. 05,P 0. 01)。结论高血压患者进行老年综合评估,能够提高或维持其生活质量,使降压治疗效果更优化。     

自发性高血压大鼠运动降压与动脉压力反射敏感性的相关性

目的：探讨运动训练对自发性高血压大鼠（SHR）动脉压力反射（BRS）敏感性的影响及血压与BRS的相关性。方法：雄性SHR大鼠和正常血压Wistar大鼠各20只被随机各分成常态（安静）组和运动组,每组10只。两运动组大鼠进行8周跑台训练（20m／min,60min／d,6d／周）。采用尾套法测量清醒大鼠的收缩压（SBP）和心率（HR）。静脉注射苯肾上腺素（PE）和硝普钠（NP）分别诱发降压反射和升压反射,以反射前后的心率与平均动脉压变化值之比（HR／MAP）作为降压反射敏感性（BRS-PE）和升压反射敏感性（BRS-NP）指标。结果：8周运动结束时,SHR运动组静息SBP[（163．6±10．7）mmHg比（180．0±8．5）mmHg]和HR[（345．0±9．8）次／min比（368．4±13．3）次／mini较SHR常态组显著下降,P均〈0．01。Wistar运动组静息SBP与常态组无明显差异（P〉0．05）,但HR较常态组显著下降[（343．9±10．2）次／min比（362．2±13．0）次／min,P〈0．05]。SHR运动组的BRS．PEE（1．32±0．22）bpm／mmHg比（0．89±0．13）bpm／mmHg]和BRS—NP[（1．21±0．26）bpm／mmHg比（0．60±0．09）bpm／mmHg]较SHR常态组明显提高,P均〈0．01,但仍低于Wistar常态组的~RSVBRS—PE：（1．96±0．23）bpm／mm—Hg,BRS．NP：（1．32±0．17）bpm／mmHg]。Pearson线性相关分析显示,SHR常态组和运动组的平均动脉压与BRS呈显著负相关（r=-0．734,P〈0．01）。结论：运动训练能显著降低SHR的血压,它与运动改善压力反射敏感性有关,提示增强的压力反射功能可能是高血压运动疗法的重要机制。     

心理干预联合草酸艾司西酞普兰对老年高血压焦虑患者的血压影响

目的探讨老年高血压伴广泛性焦虑患者给予心理干预联合草酸艾司西酞普兰对血压的控制作用。方法入选2011年8月至2014年3月期间于北京礼士路社区居住的老年高血压伴广泛性焦虑的患者28例,其中,男性18例,女性10例,年龄61~84岁,平均(72±6)岁。在常规降压治疗基础上,进行心理干预,并加服草酸艾司西酞普兰,疗程12周。干预12周后观察血压变化、焦虑评价量表(SAS)评分等指标。结果 28例患者收缩压、舒张压干预后均较干预前明显下降,分别为[(136.2±9.1)mm Hg vs.(164.6±8.9)mm Hg](1 mm Hg=0.133k Pa),[(81.3±8.8)mm Hg vs.(105.7±9.4)mm Hg];SAS评分干预后较干预前下降,为[(38.22±6.64)分vs.(56.63±12.35)分],差异有统计学意义(P均0.05)。结论心理干预联合草酸艾司西酞普兰治疗可以改善老年高血压伴广泛性焦虑患者血压和焦虑状态。     

乙酰胆碱诱发犬急性心房颤动模型的研究

目的 :研究乙酰胆碱 （ACh）诱发犬急性心房颤动模型的效果及机制。方法 :取 10条健康杂种犬 ,给予持续静注 ACh及心房快速起搏 ,测定房颤持续时间 ,根据房颤持续时间逐渐增加药量 ,直至通过心房快速起搏可以诱发出持续性房颤 （≥ 3m in）为止。给药前及给药后测定心率 ,校正窦房结恢复时间 ,心房有效不应期 ,给药前后及房颤发生后测定左室内压及左室内压最大上升、下降速率 （± dp/ dtmax）。结果 :在给予 ACh前 ,通过心房快速起搏均未能诱发出持续性房颤 ,随着 ACh量的逐渐增加 ,诱发出房颤的时间逐渐延长 ,当增加到一定量 （18± 8μg· kg- 1·min- 1 ）之后 ,10只犬均可以通过心房快速起搏诱发出持续性房颤 ,有 1只犬不需诱发即可出现 ,其持续时间为 34 4± 173s。测定犬心率明显减慢 （15 7± 2 5 vs138± 2 0· m in- 1 ,P<0 .0 1） ,校正窦房结恢复时间延长 （4 4± 13vs81±2 4ms,P<0 .0 1） ,心房有效不应期明显缩短 （80± 16 vs 6 0± 13m s,P<0 .0 1） ,使用 ACh后左室内压及其最大上升、下降速率差异不显著 （140± 2 9vs 12 9± 15 m m Hg· s- 1 ,P>0 .0 5 ;2 75 2± 876 vs 2 434± 5 31mm Hg· s- 1 ;-3115± 10 6 7vs- 2 70 7± 714m m Hg· s- 1 ,P>0 .0 5 ） ,房颤发生后则明显降低 (12 9± 15 v     

尼卡地平和硝普钠治疗高血压急症的价值比较

目的 :比较静滴尼卡地平和硝普钠治疗急症高血压的疗效和安全性。方法 :急症高血压 （非危急症高血压 ）患者 92例随机分为 2组。尼卡地平组 （4 7例 ）静滴尼卡地平 30 mg,以 0 .6 μg· kg- 1· m in- 1滴速开始 ,每隔 5 m in根据患者血压调节滴速 ,直至达到目标血压后维持该滴速 ,最大剂量不超过 6 μg· kg- 1· m in- 1 ;硝普钠组 4 5例静滴硝普钠 2 5 mg,以 0 .5 μg· kg- 1· m in- 1滴速开始 ,每隔 5 min以 0 .5～ 1.5 μg· kg- 1· min- 1滴速递增 ,直至达到目标血压后维持静滴 ,最大剂量不超过 10 μg· kg- 1· min- 1。结果 :尼卡地平组 SBP从治疗前的 184± 2 2 mm Hg降至用药结束时 12 5± 9mm Hg（P<0 .0 1） ,DBP则从 10 6± 18mm Hg降至 80± 6 mm Hg（P<0 .0 1）。而硝普钠组SBP从 183± 2 1mm Hg降至 12 9± 9m m Hg,DBP从 10 5± 17m m Hg降至 83± 4 mm Hg（P<0 .0 1）。两组的率压积均较治疗前明显降低 （P<0 .0 1）。尼卡地平组不良反应发生 4例 ,硝普钠组不良反应发生 8例 ,两组无显著差异（P>0 .0 5 ）。结论 :静脉应用尼卡地平与硝普钠降压疗效相近 ,不良反应发生率低 ,可用于非危急症的重度高血压患者的治疗。     

不同性别大鼠压力感受性反射的差异及其机制的实验研究

目的 探讨不同性别Sprague-Dawley(SD)大鼠压力感受性反射（BR）的差异及其机制。方法 以SD大鼠为实验模型,用生理记录仪同时记录血压和心率,测定BR功能,并采用免疫组化的方法测定颈动脉窦（CS）外诱导型一氧化氮合酶（iNOS)的表达。结果 （1）雄性SD大鼠的BR能较雌鼠强,压力感受性反射敏感度（BRS）升高（P＜0．01）,但两者的平均动脉压无差异;（2）雌鼠CS的iNOS表达较雄鼠升高,CS处微量注射iNOS反义寡核苷酸（iNOS－ASODNA）后,雄、雌鼠CS的iNOS表达均有明显下降（P均＜0．01）,而且两性之间iNOS表达差异消失;（3）颈动脉窦处微量注射iNOS-ASODN后,雌鼠的BRS值明显升高（P＜0．01）,升高幅度较雄鼠明显（P＜0．01）,升高后的BRS值两性之间无差异（P＞0．05）：雄、雌鼠的加压反应明显降低（P＜0．01）,下降幅度两性相比较无差异（P＞0．05）;（4）CS处微量注射iNOS-ASODN对于基础平均动脉压无影响（P＞0．05）。结论 不同性别SD大鼠的BR功能存在差异,其机制与CS的iNOS一氧化氮（NO）系统有一定的关系。     

腹式呼吸对血压及呼吸性窦性心律不齐的影响

目的 :研究腹式呼吸对血压及呼吸性窦性心律不齐 （RSA）的影响。方法 :采用反馈型腹式呼吸训练仪 ,分析2 5例正常人腹式呼吸训练前后血压及呼吸性窦性心律不齐 （RSA）的动态变化。结果 :腹式呼吸训练 10min ,2 0min后RSA比静息状态显著减少 （ms,4 7± 13vs 36± 10 ,P <0 .0 1;4 8± 16vs 36± 10 ,P <0 .0 1） ,RSA在停止训练后较训练时降低 ,但较训练前显著减少 （ms,4 1± 16vs 36± 10 ,P <0 .0 1） ;训练 10min、2 0min后血压显著下降 ,收缩压更为明显 （kPa,14 .5± 1.5vs 14 .9± 1.3,P <0 .0 5 ;14 .5± 1.2vs 14 .9± 1.3,P <0 .0 5 ） ,舒张压无明显变化。结论 :腹式呼吸能降低血压、增强心副交感神经的兴奋性。     

胰岛素瘤的解剖分布特点分析

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。     

Pathogenesis of carcinoma of the papilla of Vater

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.     

Demonstration of the mechanism of action of biguanides

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.     

Lack of correlation of degree of villous atrophy with severity of clinical presentation of coeliac disease

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.     

血吸虫童虫生长发育及其机制的研究进展

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。     

124例耐多药结核分枝杆菌基因突变特征分析

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。     

氯硝柳胺悬浮剂的毒性评价

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。     

Assessment of quality of life of parents of children with juvenile chronic arthritis

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     

Numerical Simulation of the Effect of Rate of Change of Glucose on Measurement Error of Continuous Glucose Monitors

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.     

Study of constancy of hydrogen-consuming flora of human colon

The constancy of the hydrogen consuming flora of the human colon was studied in 15 healthy subjects via two measurements obtained 18 to 36 months apart. Hydrogen disappearance rate and the major products of H₂-consuming bacteria, methane and sulfide, were measured during incubation of fecal homogenates with excess hydrogen and sulfate. In 11/15, the hydrogen consumption rate and the predominant hydrogen-consuming pathway (methanogenesis, sulfate reduction, or neither) remained constant. However, major shifts in these pathways were observed in four subjects, with two losing and two gaining the ability to produce methane. Methanogenesis was associated with the highest hydrogen consumption rate. This study demonstrates that clinically unrecognizable, major alterations of the colonic flora occur in healthy subjects. Understanding of the factors responsible for these alterations might allow for therapeutic manipulation of the colonic flora.Supported in part by the Department of Veterans Affairs and NIDDKD RO1 DK 13309-25.