医养结合机构老年坠积性肺炎患者多重耐药菌分布及感染的危险因素

目的探讨医养结合机构老年坠积性肺炎多重耐药菌(MDRO)分布及感染的危险因素。方法收集2018年5月至2019年11月入住山东大学第二医院南部院区(济南善德养老院)老年医学科接受住院治疗的老年坠积性肺炎患者80例。根据微生物培养是否检出MDRO分为MDRO组(n=39)和非MDRO组(n=41)。分析MDRO感染后病原菌分布及感染的危险因素。结果 MDRO组主要为鲍曼不动杆菌和铜绿假单胞菌感染。单因素分析显示,近期ICU入住史、住院时间、血清白蛋白水平、抗生素使用时间、抗生素使用数量是老年坠积性肺炎患者MDRO感染的危险因素(P0.05);多因素分析显示,大量的抗菌药物使用(OR=2.048,95%CI 1.375～3.050;P0.001)是发生MDRO感染的独立危险因素,高水平的血清白蛋白水平(OR=0.849,95%CI 0.746～0.966;P=0.013)是发生MDRO感染的独立保护因素。结论老年坠积性肺炎患者发生MDRO以鲍曼不动杆菌和铜绿假单胞菌感染常见。血清白蛋白水平、抗菌药物使用数量是发生MDRO感染的独立危险因素。     

老年食管癌根治术后发生肺部感染临床危险因素分析

目的探讨老年食管癌术后发生肺部感染临床危险因素分析。方法回顾性分析2015年2月至2018年1月武汉市第一医院行食管癌根治术老年患者临床资料450例。根据患者术后是否发生肺部感染分为感染组(术后发生肺部感染,94例)和未感染组(术后未发生肺部感染,356例),收集两组患者一般临床资料及可疑危险因素,用统计学软件分析影响老年食管癌术后发生肺部感染相关因素。结果单因素分析得出,感染组和未感染组在年龄、吸烟、合并糖尿病、合并慢性阻塞性肺疾病、手术时间、FEV1/FVC、术前白蛋白、手术通气方式方面比较无统计学意义(P 0.05)。多因素分析得出,高龄(OR=2. 614,95%CI为1. 214～5. 628,P 0.05)、吸烟(OR=2.330,95%CI为1.021～5.317,P 0.05)、合并糖尿病(OR=1.614,95%CI为1.102～2.364,P 0.05)、合并慢性阻塞性肺疾病(OR=1. 944,95%CI为1. 301～2.905,P 0. 05)、较长的手术时间(OR=2. 025,95%CI为1.305～3.142,P 0.05)为术后肺部感染的独立危险因素,较高的术前白蛋白(OR=0.885,95%CI为0.813～0.963,P 0.05)、术中采用TLV通气方式(OR=0.682,95%CI为0.813～0.907,P 0.05)为术后肺部感染的独立保护因素。结论影响老年食管癌根治术后肺部感染发生危险因素较多,包括高龄、吸烟、合并糖尿病和慢性阻塞性肺疾病、手术时间延长、术前白蛋白低下、术中OLV通气模式等,临床中应针对性进行干预和预防,以降低老年食管癌根治术术后肺部感染发生风险。     

老年呼吸机相关性肺炎死亡危险因素

目的对老年呼吸机相关性肺炎(VAP)患者的死亡危险因素进行logistic回归分析,并提出综合防治措施。方法回顾性收集2011年4月至2017年2月在贵州医科大学第三附属医院住院的682例、年龄≥60岁的老年VAP患者的临床资料,对21个可能与老年VAP患者死亡的危险因素进行了多因素Logistic回归分析。结果年龄(≥70岁)、急性生理与慢性健康评估(APACHE)Ⅱ评分15分、格拉斯哥昏迷量表(GCS)评分7分、吸烟史、慢性心肺基础疾病史、糖尿病史、入住ICU、保留导尿、深静脉置管、感染类型(迟发型)、机械通气时间 15 d、多重耐药菌感染、真菌感染、联用抗菌药物、糖皮质激素、血清白蛋白浓度(35 g/L)、器官损害数目≥3个、血糖(≥10 mmol/L)、血红蛋白浓度(90 g/L)等19个因素均是老年患者VAP死亡的危险因素(P0. 05),其中APACHEⅡ评分 15分(OR=2. 463,95%CI 1. 461~4. 151)、机械通气时间 15 d(OR=2. 521,95%CI 1. 658~3. 833)、多重耐药菌感染(OR=5. 623,95%CI 1. 973~3. 331)、真菌感染(OR=6. 298,95%CI 1. 809~3. 375)、糖皮质激素(OR=2. 061,95%CI 1. 255~3. 384)、血清白蛋白浓度(35 g/L)(OR=3. 267,95%CI 1. 385~2. 127)、器官损害数目≥3个(OR=3. 407,95%CI 2. 144~5. 416)、血糖(≥10 mmol/L)(OR=2. 736,95%CI 1. 100~1. 735)等8个因素均为独立危险因素。结论老年VAP患者死亡与多种因素有关,临床应采取以防治主要危险因素为主的综合防治措施,以减少其死亡率。     

高龄肺部感染患者发生吸入性肺炎的临床特点及危险因素

目的分析高龄肺部感染患者发生吸入性肺炎(AP)的临床特点及危险因素。方法回顾性研究2013年1月至2016年1月在空军军医大学西京医院老年病科住院治疗的高龄(≥80岁)医院获得性肺部感染患者共212例,依据是否发生AP分为2组:AP组(n=61)和非AP组(n=151)。收集患者临床资料,包括性别、年龄、基础疾病、用药史等,分析高龄肺部感染患者发生AP的临床特点及危险因素。采用SPSS 18.0软件进行数据处理。结果 212例高龄肺部感染患者中,61例(占35.4%)发生AP。2组患者痰培养均以革兰氏阴性菌感染为主。AP组住院时间较非AP组[(21.4±2.1)和(15.7±3.1)d]显著延长(P=0.034),病死率较非AP组显著增高(24.6%和8.0%,P=0.002)。多因素logistic回归分析发现,年龄大(OR=4.897,95%CI 3.556～7.878)、认知障碍(OR=6.799,95%CI 2.931～9.443)、吞咽功能障碍(OR=8.345,95%CI 1.062～5.133),以及服用抑酸药(OR=4.667,95%CI 4.283～8.343)、镇静药(OR=3.886,95%CI 1.944～7.174)、硝酸酯类药物(OR=3.445,95%CI 2.977～6.437)、钙离子拮抗剂(OR=3.568,95%CI 4.345～7.868)、血管紧张素转化酶抑制剂/血管紧张素Ⅱ受体阻滞剂(ACEI/ARB)(OR=6.876,95%CI 2.192～9.458)是高龄肺部感染患者发生AP的独立危险因素(P0.05)。结论高龄肺部感染患者AP发生率高。年龄大、认知障碍、吞咽功能障碍及服用抑酸药、镇静药、硝酸酯类、钙离子拮抗剂、ACEI/ARB是高龄肺部感染患者发生AP的独立危险因素。     

老年胃癌根治术病人术后肺部感染的影响因素分析

目的探讨老年胃癌根治术病人的临床病理特征及术后肺部感染的影响因素。方法回顾性分析2016年1月至2019年6月我院收治的120例行根治性手术治疗的老年胃癌病人的临床资料,根据病人术后是否发生肺部感染将其分为研究组(n=26)和对照组(n=94)。比较2组病人的临床病理资料,并采用多因素Logistic回归分析老年胃癌根治术病人并发术后肺部感染的独立危险因素。结果年龄(OR=3.570,95%CI1.150~9.875)、低白蛋白血症(OR=3.003,95%CI2.851~4.623)、胃肠减压(OR=7.538,95%CI3.101~18.203)、围术期输血(OR=6.813,95%CI5.323~8.303)、伤口疼痛(OR=3.417,95%CI1.546~7.537)、吸烟史(OR=3.662,95%CI1.680~7.992)是老年胃癌根治术病人并发术后肺部感染的独立危险因素。结论老年胃癌根治术病人并发术后肺部感染的独立危险因素主要为高龄、低白蛋白血症、胃肠减压、围术期输血、伤口疼痛、吸烟史,建议针对上述因素加强干预措施。     

老年肺结核合并肺部多重耐药菌感染危险因素

目的探讨老年肺结核患者合并肺部多重耐药菌感染的危险因素。方法回顾性分析279例老年肺结核合并肺部感染患者的临床资料,根据是否检出肺部多重耐药菌感染分为多重耐药菌感染组与非多重耐药菌感染组,对肺部多重耐药菌感染相关危险因素分别进行单因素与多因素Logistic回归分析。结果 MDRO检出率29.07%,MDRO感染率25.81%,慢性阻塞性肺病(COPD)、肺心病、联用抗菌药物(≥3种)、肺部病变范围(≥3个肺叶)、空洞、使用抗菌药物时间(>14 d)、治疗使用抗菌药种类(≥3种)、肺结核类型(复治)是老年肺结核合并肺部多重耐药菌感染的独立危险因素。结论应采用积极治疗基础疾病,提高免疫功能,规范抗结核治疗减少复发与空洞形成,促进排痰,合理使用抗菌药物等综合措施,才能在一定程度上减少老年肺结核患者合并肺部多重耐药菌感染的发生。     

70岁以上老年非小细胞肺癌病人术后肺部感染的危险因素研究

目的研究70岁以上老年非小细胞肺癌(NSCLC)病人术后肺部感染的危险因素。方法对2016年6月至2018年6月在江苏省人民医院住院的141例≥70岁确诊NSCLC病人的临床资料及相关检查结果进行回顾性分析。根据术后是否有感染并发症,将其分为术后感染组65例和术后无感染组76例。比较2组病人的临床资料,采用多因素Logistic回归分析影响术后感染的危险因素。结果 2组在性别、淋巴细胞计数、外周血中性粒细胞与淋巴细胞比值、血小板与淋巴细胞计数比值、全身炎症指数、术后住院天数、围手术期使用抗生素天数和抗生素联用方面差异均有统计学意义(P005或P001)。2组临床病理特征在肿瘤突破脏层胸膜、术中淋巴结清扫、肺癌根治术联合淋巴结清扫方面差异有统计学意义(P005或P001)。多因素Logistic回归分析提示女性(OR=266,95%CI:1107～6464)、围手术期使用抗生素天数(OR=1176,95%CI:0998～1386)是老年NSCLC术后肺部感染的危险因素,术中淋巴结清扫(OR=0337,95%CI:0094～1206)是术后肺部感染的保护因素。结论性别、围手术期抗菌药物使用时限、术中淋巴结清扫为老年NSCLC术后肺部感染的影响因素。     

高龄肺部感染患者多重耐药菌的分布及临床特点

目的探讨高龄肺部感染患者多重耐药菌(MDR)的分布及临床特点。方法入选2015年1月至2016年12月在西京医院老年病科住院治疗的高龄肺部感染患者共219例。依据是否出现MDR分为2组:MDR组(n=107)和非MDR组(n=112)。分析MDR的分布情况,并比较2组患者的各临床指标,分析MDR感染的危险因素。采用SPSS 18. 0软件进行数据处理。依据数据类型,组间比较分别采用t检验或χ2检验。多因素logistic回归分析发生MRA感染的独立危险因素。结果 MDR组以鲍曼不动杆菌、铜绿假单胞菌等细菌感染多见。MDR组患者1年死亡率较对照组明显升高[30. 2%(32/106) vs 8. 0%(9/112); P 0. 05]。多因素logistic回归分析结果提示,住院时间长(OR=4. 813,95%CI 1. 234~5. 554;P=0. 032)、抗生素使用时间长(OR=3. 124,95%CI 2. 126~10. 314; P=0. 001)及有创呼吸机使用时间长(OR=4. 227,95%CI1. 470~6. 879; P=0. 041)是发生MDR感染的独立危险因素。结论高龄肺部感染MDR以鲍曼不动杆菌和铜绿假单胞菌感染多见。发生MDR感染的患者死亡率高,住院时间长、抗生素时间长、有创呼吸机使用时间长是其发生的独立危险因素。     

老年心力衰竭患者肺部感染的影响因素研究

目的 探讨老年心力衰竭患者肺部感染的影响因素。方法 选取2014年3月—2015年12月泰州市第二人民医院收治的老年心力衰竭患者82例,根据肺部感染情况分为肺部感染组40例与非肺部感染组42例,比较两组患者的临床资料,分析老年心力衰竭患者肺部感染的影响因素。结果 肺部感染组患者年龄≥80岁者所占比例、吸烟史阳性率、抗生素及激素滥用史阳性率、长期卧床者所占比例、慢性阻塞性肺疾病(COPD)发生率、糖尿病发生率、高血压发生率、C反应蛋白(CRP)水平高于非肺部感染组,左心室射血分数(LVEF)≥55%者所占比例低于非肺部感染组(P0.05);两组患者有无侵入性操作比较,差异无统计学意义(P0.05)。多因素logistic回归分析结果显示,长期卧床〔OR=4.590,95%CI(1.423,14.806)〕、COPD〔OR=3.989,95%CI(1.106,14.393)〕、糖尿病〔OR=3.557,95%CI(1.071,11.809)〕、CRP〔OR=12.778,95%CI(2.156,75.729)〕是老年心力衰竭患者肺部感染的影响因素(P0.05)。结论 长期卧床、COPD、糖尿病、CRP是老年心力衰竭患者肺部感染的影响因素,应采用有针对性的防治措施以减少老年心力衰竭患者肺部感染的发生。     

重症肺部感染患者降阶梯抗菌治疗失败的影响因素分析

目的分析重症肺部感染患者降阶梯抗菌治疗失败的影响因素。方法选取2013年2月—2016年2月惠州市第三人民医院收治的重症肺部感染患者250例,收集患者的临床资料,分析重症肺部感染患者降阶梯抗菌治疗失败的影响因素。结果 250例患者中降阶梯抗菌治疗失败65例(26.0%),成功185例(74.0%)。降阶梯抗菌治疗失败患者与降阶梯抗菌治疗成功患者性别、机械通气率、深静脉置管率、深静脉置管时间、用药方案比较,差异无统计学意义(P0.05);降阶梯抗菌治疗失败患者与降阶梯抗菌治疗成功患者年龄、清蛋白水平、机械通气时间、多重耐药菌感染发生率、抗菌药物不合理使用率比较,差异有统计学意义(P0.05)。多因素logistic回归分析结果显示,年龄〔OR=15.386,95%CI(10.215,26.143)〕、清蛋白水平〔OR=2.364,95%CI(1.380,4.128)〕、机械通气时间〔OR=2.124,95%CI(1.132,3.683)〕、多重耐药菌感染〔OR=6.892,95%CI(4.165,8.714)〕是重症肺部感染患者降阶梯抗菌治疗失败的影响因素(P0.05)。结论年龄、清蛋白水平、机械通气时间、多重耐药菌感染是重症肺部感染患者降阶梯抗菌治疗失败的影响因素。     

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.