NLR、RDW和PCT评估老年社区获得性肺炎患者病情严重程度及预后的临床价值

摘要 目的：探讨中性粒细胞/淋巴细胞比值（NLR）、红细胞分布宽度（RDW）及降钙素原（PCT）在老年社区获得性肺炎（CAP）患者病情严重程度及预后评估中的临床价值。方法：回顾性分析2018年1月～2020年11月期间我院收治的127例老年CAP患者的临床资料,根据英国胸科协会改良肺炎评分(CURB-65)分为低危组（CURB-65评分＜3分,n=69例）和高危组（CURB-65评分≥3分,n=58例）;根据患者转归分为存活组（n=114例）和死亡组（n=13例）,比较各组患者的基线资料、NLR、RDW、PCT及其他实验室检查指标,并分析NLR、RDW、PCT与CURB-65评分的相关性以及预后的影响因素。结果：高危组NLR、RDW和 PCT水平均显著高于低危组,差异有统计学意义（P＜0.05）。经Pearson相关性分析可得：NLR、RDW、PCT与CURB-65评分均呈正相关关系（P＜0.05）。生存组患者白细胞计数（WBC）、中性粒细胞（NEU）、NLR、RDW、PCT和D-二聚体（D-Dimer）水平均低于死亡组,差异具有统计学意义（P＜0.05）,经多因素Logistic回归分析可得：NLR、RDW、PCT均是老年CAP患者预后的影响因素（均OR＞1,P＜0.05）。结论：NLR、RDW和PCT与CURB-65评分相关,且均是老年CAP患者预后的影响因素,NLR、RDW和PCT对老年CAP患者病情严重程度及预后具有一定的评估价值。     

系统性炎症指标预测脓毒性休克预后的临床价值

摘要 目的：探讨系统性炎症指标对脓毒性休克预后的临床预测价值。方法：回顾性分析2019年7月至2022年7月贵州省铜仁市石阡人民医院重症医学科救治的脓毒性休克患者46例（治疗组），46例患者随访60 d后根据临床预后分为存活组22例和死亡组24例。收集患者入院后治疗前血常规中白细胞、中性粒细胞、淋巴细胞、单核细胞和血小板计数，计算中性粒细胞与淋巴细胞比值（neutrophil-to-lymphocyte ratio，NLR）、血小板与淋巴细胞比值（platelet-to-lymphocyte ratio，PLR）、淋巴细胞与单核细胞比值（lymphocyte-to-monocyte ratio，LMR），同时记录生化中肌酐（Cr）、C反应蛋白（CRP）等指标，比较治疗后存活组和死亡组上述指标的差异，观察NLR、PLR、LMR与Cr水平的相关性。以Shapiro-Wilk检验进行正态性检验；Mann-Whitney U检验非正态分布的两组计数资料；相关性研究采用Spearman相关性分析；影响脓毒性休克预后的独立危险因素采用二分类logistic回归分析，并绘制生存曲线和受试者工作特征曲线（ROC曲线），评估危险因素预测脓毒性休克发生死亡事件的价值。结果：治疗组与正常对照组相比，入院时白细胞、中性粒细胞、淋巴细胞、单核细胞、血小板计数、NLR、PLR、LMR，差异有统计学意义（P＜0.01）。患者入院当天中性粒细胞、淋巴细胞、NLR、CRP在存活组与死亡组之间比较，差异有统计学意义（均P＜0.05），其余指标差异无统计学意义。脓毒性休克患者肌酐水平与NLR呈正相关（P＜0.01）。多因素logistic回归分析，结果显示仅有NLR是影响脓毒性休克患者60d预后的独立危险因素（OR=1.038，P= 0.031）。ROC曲线分析发现曲线下面积为0.705（95% CI: 0.597~0.812，P=0.001）；根据约登指数原则提示NLR预测死亡风险的截断值为16.35（敏感度为66.7%，特异度为72.7%），即NLR＞16.35时脓毒性休克的死亡率较高。Kaplan-Meier法分析治疗后60天生存预后，结果显示NLR≤16.35组中位生存期显著高于NLR＞16.35组，（χ²=5.568，P= 0.018）。结论：ICU初始NLR有助于脓毒性休克的病情判断并对患者生存预后评估有一定的临床价值，是发生死亡事件的独立预测指标。     

中性粒细胞与淋巴细胞比值在脓毒症诊断和预后中的临床价值

摘要 目的：探讨中性粒细胞与淋巴细胞比值在脓毒症诊断和预后中的临床价值。方法：回顾性分析2017年1月至2020年1月于我院就诊的180例脓毒症患者的临床资料,分析其白细胞计数、中性粒细胞比、淋巴细胞比、中性粒细胞/淋巴细胞比值（Neutrophil/Lymphocyte ratio, NLR）、血肌酐、血糖、急性生理与慢性健康评分（Acute physiology and chronic health score, APACHEⅡ）与脓毒血症严重程度和预后的相关性。结果：180例患者中,与NLR比值低的患者相比,NLR比值高的患者死亡率更高,脓毒血症更严重,差异具有统计学意义（P<0.05）;单因素分析表明,APACHEⅡ评分和NLR值在存活组死亡组患者中差异显著,多因素回归分析结果表明,NLR比值和APACHEⅡ评分是脓毒血症预后和死亡的独立预测因子。结论：NLR值低是脓毒血症患者预后的保护因子,在临床工作中我们应充分重视NLR值高的脓毒血症患者。     

血清NGAL、GLI及NLR对脑卒中并发肺部感染患者预后的预测价值分析

摘要 目的：探究血清中性粒细胞明胶酶相关脂质蛋白（NGAL）、血糖不稳定指数（GLI）、中性粒细胞与淋巴细胞比值（NLR）对脑卒中并发肺部感染患者预后的预测价值。方法：选取2020年10月-2022年6月我院收治的98例脑卒中并发肺部感染患者，随访3个月，根据预后分为预后良好组67例与预后不良组31例，比较两组临床资料、实验室指标及血清NGAL、GLI、NLR水平，分析NGAL、GLI、NLR与临床肺部感染评分（CPIS）、美国国立卫生研究院卒中量表（NIHSS）评分、急性缺血性卒中相关性肺炎评分（AIS-APS）、肿瘤坏死因子-α（TNF-α）、超敏C反应蛋白（hs-CRP）、白细胞（WBC）计数的相关性，多因素Logistic回归分析脑卒中并发肺部感染患者预后不良的影响因素，受试者工作特征曲线（ROC）分析NGAL、GLI、NLR单独预测及联合预测脑卒中并发肺部感染患者预后不良的价值。结果：预后不良组住院时间、空腹血糖、CPIS评分、AIS-APS评分、NIHSS评分、TNF-α、hs-CRP、WBC显著高于预后良好组（P＜0.05）。预后不良组血清NGAL、GLI、NLR、中性粒细胞计数显著高于预后良好组（P＜0.05），淋巴细胞计数显著低于预后良好组（P＜0.05）。NGAL、GLI、NLR与CPIS评分、AIS-APS评分、NIHSS评分、TNF-α、hs-CRP、WBC均呈正相关（P＜0.05）。高NGAL、GLI、NLR、CPIS评分、NIHSS评分、TNF-α为脑卒中并发肺部感染患者预后不良的危险因素（P＜0.05）。NGAL、GLI、NLR联合预测脑卒中并发肺部感染患者预后不良的AUC为0.864，其价值显著优于各项指标单独检测（P＜0.05）。结论：血清NGAL、GLI、NLR在脑卒中并发肺部感染预后不良患者中升高较为显著，三者联合对于脑卒中并发肺部感染患者预后不良有较好的预测价值。     

定量脑电图联合PLR、NLR、MPV/PLT比值在急性脑梗死静脉溶栓治疗疗效和短期预后评估中的临床应用价值

摘要 目的：探究定量脑电图联合血小板/淋巴细胞比值(PLR)、中性粒细胞/淋巴细胞比值(NLR)、血小板平均体积(MPV)/血小板计数(PLT)比值在急性脑梗死（ACI）静脉溶栓治疗疗效和短期预后评估中的临床应用价值。方法：选择2019年10月-2022年10月于长沙市第一医院收治的119例ACI患者为研究对象,根据静脉溶栓治疗疗效分为溶栓治疗有效组和溶栓治疗无效组,对比两组的功率比指数（DTABR）、PLR、NLR、MPV/PLT比值变化;根据ACI患者预后情况分为预后良好组与预后不良组,单因素分析比较两组基线临床资料,多因素Logistic回归模型分析ACI静脉溶栓预后影响因素,采用受试者工作特征曲线（ROC）分析各指标对ACI静脉溶栓预后的预测效能。结果：治疗后,溶栓治疗无效组DTABR、中性粒细胞计数、PLT、MPV、PLR、NLR、MPV/PLT比值显著高于溶栓治疗有效组（P＜0.05）,淋巴细胞计数显著低于溶栓治疗有效组（P＜0.05）。与预后良好组比较,预后不良组年龄、入院时美国国立卫生院神经功能缺损评分(NIHSS)评分、溶栓24 h后NIHSS评分、高血压史占比、DTABR、中性粒细胞计数、PLT、MPV、PLR、NLR、MPV/PLT比值显著升高（P＜0.05）,淋巴细胞计数显著降低（P＜0.05）。Logistic回归模型,显示入院时及溶栓24 h后NIHSS评分升高、DTABR升高、PLR升高、NLR升高、MPV/PLT比值升高是ACI静脉溶栓预后不良的危险因素（P＜0.05）。ROC曲线显示,DTABR、PLR、NLR、MPV/PLT比值联合预测ACI静脉溶栓预后的效能较高。结论：定量脑电图DTABR、PLR、NLR、MPV/PLT比值与ACI静脉溶栓治疗疗效和短期预后关系密切,对于短期预后有较高的预测价值。     

NLR联合H-FABP对Stanford B型主动脉夹层腔内修复术患者预后的预测价值

摘要 目的：研究中性粒细胞/淋巴细胞比值（NLR）联合心型脂肪酸结合蛋白（H-FABP）对Stanford B型主动脉夹层胸主动脉腔内修复术（TEVAR）患者预后的预测价值。方法：选取2017年6月至2020年9月在我院接受TEVAR治疗的172例Stanford B型主动脉夹层患者为研究对象。收集所有患者基线资料、相关实验室指标水平,随访追踪患者预后,按照预后差异分作预后不良组和预后良好组,比较两组患者基线资料和实验室指标差异,采用多因素Logistic回归分析患者预后的影响因素,以受试者工作特征（ROC）曲线分析NLR联合H-FABP对患者预后的预测价值。结果：预后不良组收缩压、舒张压高于预后良好组（P＜0.05）。预后不良组NLR、H-FABP、白细胞计数（WBC）水平均高于预后良好组,而血小板计数（PLT）水平低于预后良好组（P＜0.05）。多因素Logistic回归分析显示：收缩压、舒张压、NLR、H-FABP、WBC均是Stanford B型主动脉夹层TEVAR患者预后的影响因素（P＜0.05）。ROC曲线分析显示：NLR联合H-FABP预测Stanford B型主动脉夹层TEVAR患者预后的曲线下面积为0.876均高于上述两项指标单独预测的0.626及0.712。结论：NLR联合H-FABP对Stanford B型主动脉夹层TEVAR患者预后具有一定预测价值。     

NLR、PLR与分化型甲状腺癌术后131I清甲效果的关系及其预测价值分析

摘要 目的：探讨中性粒细胞/淋巴细胞比值（NLR）、血小板/淋巴细胞比值（PLR）与分化型甲状腺癌（DTC）术后碘131（¹³¹I）清甲治疗效果的关系及对DTC术后¹³¹I清甲效果的预测价值。方法：选择2019年3月至2021年12月在江苏大学附属徐州医院行甲状腺切除术且术后进行¹³¹I清甲治疗的DTC患者150例为研究对象,根据¹³¹I清甲治疗效果分为清甲成功组（107例）和清甲未成功组（43例）,通过检查血常规获得中性粒细胞计数、血小板计数、淋巴细胞计数并计算NLR、PLR,比较两组NLR、PLR;采用单因素及多因素logistics回归模型分析¹³¹I清甲疗效的影响因素,采用受试者工作特征曲线（ROC）分析NLR、PLR对¹³¹I清甲治疗效果的预测价值。结果：清甲成功组NLR、PLR低于清甲未成功组（P＜0.05）,单因素分析显示清甲成功组促甲状腺激素（TSH）高于清甲未成功组,甲状腺球蛋白（Tg）水平低于清甲未成功组,清甲成功组病灶最大径小于清甲未成功组（P＜0.05）;多因素logistics回归分析显示,高NLR、PLR、Tg是¹³¹I清甲治疗失败的独立危险因素（P＜0.05）;NLR、PLR及联合检测预测¹³¹I清甲治疗效果的ROC曲线下面积（AUC）分别为0.760、0.732、0.829,NLR与PLR联合检测的AUC高于二者单独检测。结论：高NLR、PLR是DTC术后¹³¹I清甲未成功的独立危险因素,早期检测NLR、PLR对DTC术后¹³¹I清甲治疗效果具有较好的预测价值。     

术前修正衰弱指数联合C反应蛋白/白蛋白比值、中性粒细胞/淋巴细胞比值对老年结直肠癌患者术后谵妄发生风险的评估价值

摘要 目的：探讨术前修正衰弱指数（mFI）联合C反应蛋白/白蛋白比值（CAR）、中性粒细胞/淋巴细胞比值（NLR）预测老年结直肠癌患者术后谵妄发生风险的价值。方法：选择2020年1月至2021年12月郑州大学第一附属医院收治的352例行腹腔镜手术治疗的老年结直肠癌患者,根据术后谵妄发生情况将患者分为谵妄组（63例）和无谵妄组（289例）。术前采用mFI评估衰弱状态,检测C反应蛋白、白蛋白、中性粒细胞计数和淋巴细胞计数,计算CAR和NLR。分析影响老年结直肠癌患者术后发生谵妄的危险因素以及mFI、CAR和NLR预测老年结直肠癌患者术后发生谵妄的价值。结果：谵妄组mFI、CAR、NLR大于无谵妄组（P＜0.05）。年龄、饮酒史、脑血管病史、精神病史、术后转重症监护病房（ICU）比例高于无谵妄组（P＜0.05）。年龄、mFI、CAR、NLR升高是老年结直肠癌患者术后发生谵妄的危险因素（P＜0.05）。联合mFI、CAR、NLR预测老年结直肠癌患者术后发生谵妄的曲线下面积为0.835,高于单独mFI、CAR、NLR预测的0.688、0.741、0.733。结论：mFI、CAR、NLR升高是老年结直肠癌患者术后发生谵妄的危险因素,三指标联合检测有助于评估老年结直肠癌患者术后发生谵妄的风险。     

DCE-MRI定量参数联合NLR、MLR对脑胶质瘤患者预后的预测价值

摘要 目的：研究动态对比增强扫描-核磁共振检查（DCE-MRI）定量参数联合中性粒细胞计数/淋巴细胞计数比（NLR）及单核细胞计数/淋巴细胞计数比（MLR）对脑胶质瘤患者预后的预测价值。方法：选择从2020年1月到2022年6月在我院接受治疗的脑胶质瘤患者130例作为观察对象。患者均实施脑胶质瘤切除术后放疗,根据预后评价分为预后良好组（n=48）与预后不良组（n=82）。比较两组DCE-MRI定量参数、NLR、MLR;单因素和多因素分析患者预后不良的影响因素;采用受试者工作特征（ROC）曲线分析DCE-MRI定量参数联合NLR、MLR对预后不良的预测价值。结果：随访1年无失访,预后不良组的转运常数（Ktrans）、血管外细胞间隙体积百分数（Ve）、NLR及MLR较预后良好组明显更高（P＜0.05）。预后不良组年龄和肿瘤分级为Ⅲ～Ⅳ级、低分化及术后放疗的比例均分别高于预后良好组（P＜0.05）,卡氏（KPS）评分低于预后良好组（P＜0.05）。单因素及多因素Logistic回归分析发现,Ktrans、Ve、NLR及MLR升高是预后不良的危险因素（P＜0.05）。ROC曲线分析发现,DCE-MRI定量参数Ktrans、Ve联合NLR、MLR对预后不良患者的预测价值最高,其曲线下面积（AUC）为0.874,灵敏度为95.21%,明显高于其他各项单独检测的结果。结论：脑胶质瘤预后不良患者的NLR、MLR与DCE-MRI定量参数异常升高,且三项联合有助于提升脑胶质瘤患者预后的预测价值。     

NLR、IL-6及鼻窦CT评分对慢性鼻窦炎伴鼻息肉的诊断价值分析

摘要 目的：探讨外周血中性粒细胞/淋巴细胞比值（NLR）、血清白细胞介素-6（IL-6）及鼻窦CT评分诊断慢性鼻窦炎伴鼻息肉（CRSwNP）的价值。方法：选择2019年2月至2021年12月济宁医学院附属医院收治的91例CRSwNP患者纳入观察组，87例鼻中隔偏曲患者纳入对照组，根据《中国慢性鼻窦炎诊断与治疗指南（2018）》将CRSwNP患者分为轻度组（29例）、中度组（40例）和重度组（22例）。所有受试者均检测外周血中性粒细胞、淋巴细胞计数以及血清IL-6水平，计算外周血NLR，行鼻窦CT检查，根据CT检测结果，采用Lund-Mackay CT评分标准对受试者进行鼻窦CT评分。对比各组外周血NLR、血清IL-6水平及鼻窦CT评分差异，分析CRSwNP 患者外周血NLR、血清IL-6与鼻窦CT评分的相关性以及外周血NLR、血清IL-6、鼻窦CT评分诊断CRSwNP的价值。结果：观察组外周血NLR、血清IL-6水平及鼻窦CT评分均高于对照组（P＜0.05）。重度组外周血NLR、血清IL-6水平及鼻窦CT评分均高于中度组和轻度组（P＜0.05），且中度组高于轻度组（P＜0.05）。CRSwNP患者外周血NLR、血清IL-6水平与鼻窦CT评分均呈正相关（r=0.502、0.539，P＜0.05）。外周血NLR、血清IL-6及鼻窦CT评分诊断CRSwNP的曲线下面积（AUC）分别为0.683、0.659、0.697，联合三项指标诊断CRSwNP的AUC为0.882，高于各指标单独诊断。结论：外周血NLR、血清IL-6水平及鼻窦CT评分上升可反映CRSwNP患者病情加重，外周血NLR、血清IL-6水平与鼻窦CT评分呈正相关，外周血NLR、血清IL-6及鼻窦CT评分联合诊断CRSwNP具有一定的临床价值。     

ATP/ADP exchange activity of gastric (H+ + K+)-ATPase

The ATP/ADP exchange is shown to be a partial reaction of the $\text{(}\text{H}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ by the absence of measurable nucleoside diphosphokinase activity and the insensitivity of the reaction to $\text{P}{}^1$, $\text{P}{}^5$ -di(adenosine-5′) pentaphosphate, a myokinase inhibitor. The exchange demonstrates an absolute requirement for Mg²⁺ and is optimal at an ADP/ATP ratio of 2. The high ATP concentration ($\text{K}{}_{0.5}\text{= 116 μ}\text{M}$) required for maximal exchange is interpreted as evidence for the involvement of a low affinity form of nucleotide site. The ATP/ADP exchange is regarded as evidence for an ADP-sensitive form of the phosphoenzyme. In native enzyme, pre-steady state kinetics show that the formation of the phosphoenzyme is partially sensitive to ADP while modification of the enzyme by pretreatment with 5,5′-dithiobis(2-nitrobenzoic acid) (DTNB) in the absence of Mg²⁺ results in a steady-state phosphoenzyme population, a component of which is ADP sensitive. The ATP/ADP exchange reaction can be either stimulated or inhibited by the presence of K⁺ as a function of pH and Mg²⁺.     

Characterization of cytochrome P-450SCC-containing liposomes

Purified cytochrome $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ from bovine adrenocortical mitochondria was incorporated into liposomes by the cholate-dilution method utilizing either dialysis or Sephadex gel filtration. Among synthetic phospholipids tested, dioleoylglycerophosphocholine showed the best stability during the incorporation of $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ into liposomes. A maximum amount of heme was incorporated into liposomes at a molar ratio of phospholipid to the cytochrome of approx. 200. When $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ was incorporated into the dioleoylglycerophosphocholine liposomes by the cholate-filtration method, the $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}\text{-}\text{containing liposomes}$ showed two major populations on the elution pattern of the Sepharose 4B gel filtration, and were seen at a diameter of 200–600 Å and its aggregated forms. When the cytochrome was incorporated into dioleoylglycerophosphocholine liposomes or cholesterol-free adrenocortical mitochondrial liposomes, $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ was less stable than $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ in aqueous solution. Cholesterol or adrenodoxin markedly stabilized the liposomal $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$. Liposomal $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ required cholesterol for its optimum reduction with adrenodoxin, adrenodoxin reductase, and NADPH in the presence of CO. About 70% of the total heme in the dioleoylglycerophosphocholine liposomes was reduced by the enzymatic reduction in the presence of cholesterol, indicating that 70% of the total molecules are exposed to the surface of the outer monolayer. In order to see the location of the heme in membrane, the dioleoylglycerophosphocholine-liposomal $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$ was subjected to $\text{p-}\text{chloromercuriphenyl sulfonic acid}$ treatment. This reagent destroyed the liposomal $\text{P}{}_{\mathrm{<mtext>450</mtext><mtext>SCC</mtext>}}$. These results suggest that the heme is located in the proximity of the $\text{p-}\text{chloromercuriphenyl sulfonic acid}$ reacting sites which are exposed to the surface, or located on the vincinity of polar heads of the membrane.     

A/California/7/2009与A/California/4/2009病毒感染力比较

目的甲型H1N1流感病毒A/California/7/2009与A/California/4/2009病毒序列比较同源性在99%以上,本实验旨在比较两株病毒感染BALB/c小鼠研究感染力强弱。方法分别将A/California/7/2009（CA7）与A/California/4/2009（CA4）两株病毒分别连续10倍稀释后,对4~6周龄雌性BALB/c小鼠经乙醚麻醉后进行滴鼻攻毒,每个稀释度接种10只实验小鼠,测定CA7 MLD50为101.24/0.05 mL,检测小鼠感染、致病的多项指标,观察期为14 d。结果相同TCID50的CA7和CA4病毒感染小鼠,CA4感染小鼠后14 d内死亡率为20%,而CA7感染小鼠后8 d内死亡率为100%。CA7 106TCID50感染的小鼠病理表现为重度弥漫性间质性肺炎,CA4 106TCID50感染的小鼠病理表现为中度-重度间质性肺炎。结论在相同条件下,CA7感染力明显强于CA4。     

AutoFACT: AnAutomaticFunctionalAnnotation andClassificationTool

Background  

Assignment of function to new molecular sequence data is an essential step in genomics projects. The usual process involves similarity searches of a given sequence against one or more databases, an arduous process for large datasets.     

Ligand-dependent reactivity of (Na+ + K+)-ATPase with showdomycin

Showdomycin inhibited pig brain ($\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ with pseudo first-order kinetics. The rate of inhibition by showdomycin was examined in the presence of 16 combinations of four ligands, i.e., Na⁺, K⁺, Mg²⁺ and ATP, and was found to depend on the ligands added. Combinations of ligands were divided into five groups in terms of the magnitude of the rate constant; in the order of decreasing rate constants these were: (1)$\text{Na}{}^{\mathrm{+}}\text{+}\text{Mg}{}^{\mathrm{2+}}\text{+}\text{ATP}$, (2) $\text{Mg}{}^{\mathrm{2+}}$, $\text{Mg}{}^{\mathrm{2+}}\text{+}\text{K}{}^{\mathrm{+}}$, $\text{K}{}^{\mathrm{+}}$ and none, (3) $\text{Na}{}^{\mathrm{+}}\text{+}\text{Mg}{}^{\mathrm{2+}}\text{,}\text{Na}{}^{\mathrm{+}}$, $\text{K}{}^{\mathrm{+}}\text{+}\text{Na}{}^{\mathrm{+}}$ and $\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{+}\text{Mg}{}^{\mathrm{2+}}$, (4) $\text{Mg}{}^{\mathrm{2+}}\text{+}\text{K}{}^{\mathrm{+}}\text{+}\text{ATP}\text{,}\text{K}{}^{\mathrm{+}}\text{+}\text{ATP}$ and $\text{Mg}{}^{\mathrm{2+}}\text{+}\text{ATP}\text{, (5)}\text{K}{}^{\mathrm{+}}\text{+}\text{Na}{}^{\mathrm{+}}\text{+}\text{ATP}$, $\text{Na}{}^{\mathrm{+}}\text{+}\text{ATP}$, $\text{Na}{}^{\mathrm{+}}\text{+}\text{ATP}$, $\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{+}\text{Mg}{}^{\mathrm{2+}}\text{+}\text{ATP}$ and ATP. The highest rate was obtained in the presence of Na⁺, Mg²⁺ and ATP. The apparent concentrations of Na⁺, Mg²⁺ and ATP for half-maximum stimulation of inhibition ($\text{K}{}_{0.5}{}^{\mathrm{<mtext>s</mtext>}}$) were 3 mM, 0.13 mM and 4μM, respectively. The rate was unchanged upon further increase in Na⁺ concentration from 140 to 1000 mM. The rates of inhibition could be explained on the basis of the enzyme forms present, including E₁, E₂, ES, E₁-P and E₂-P, i.e., E₂ has higher reactivity with showdomycin than E₁, while E₂-P has almost the same reactivity as E₁-P. We conclude that the reaction of ($\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ proceeds via at least four kinds of enzyme form (E₁, E₂, E₁ · nucleotide and EP), which all have different conformations.     

Characterization of partially purified (Na+ + K+)-ATPase from porcine lens

The partial purification of $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ from pig lens has been achieved by treatment with deoxycholate followed by density gradient centrifugation. The specific activity of the final preparation, ranging from 300 to 500 nmol/h per mg protein, is increased approx. 100-fold compared to the homogenate. A parallel increase in $\text{p-}\text{nitrophenylphosphatase}$ activity is also observed. Sodium dodecyl sulfate (SDS) gel electrophoresis reveals six major protein bands, one of which is the 93 kDa α subunit of $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ which can be phosphorylated by reaction with [γ-³²P]ATP. A second band contains a glycoprotein which displays an apparent molecular weight of 51 000 and thus appears to be the β subunit of the enzyme. The enzyme is sensitive to ouabain with the $\text{I}{}_{50}$ for $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ and $\text{p-}\text{nitrophenylphosphatase}$ inhibition being 1.2 and 1.3 μM, respectively. Several agents which inhibit $\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ from other tissues such as oligomycin, Ca²⁺, vanadate, $\text{N-}\text{ethylmaleimide}$, $\text{p-}\text{chloromercuribenzenesulfonic acid}$ (PCMBS) and 5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB) also inhibit the lens enzyme. Monovalent cations other than K⁺ are partially effective in activating the ($\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}$)-ATPase and $\text{p-}\text{nitrophenylphosphatase}$ activities. The K⁺ congeners were relatively more effective in supporting $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ compared to $\text{p-}\text{nitrophenylphosphatase}$ activity. Other kinetic properties of the lens enzyme are also comparable to those of the enzyme from other tissues. Utilizing the partially purified membrane bound enzyme, discontinuities in Arrhenius plots of $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ activity, $\text{p-}\text{nitrophenylphosphatase}$ activity and fluoresence polarization of the fluidity probe, 1,6-diphenyl-1,3,5-hexatriene (DPH), are observed near the physiological temperature of lens. The possible significance of these observations for the mechanism of cataract formation are discussed.     

An electron spin probe study of (Na+ + K+)-ATPase-Containing membranes

The modulating effect of membrane lipids on enzyme function has been described by several investigators. We have used the spin probe $\text{N-}\text{oxyl}\text{-4′,4′-}\text{dimethyloxazolidine}\text{-12-}\text{keto}$ methyl stearate (M 12-NSE) to study this interaction in ox brain membranes enriched with $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$. This methyl ester of stearic acid is practically insoluble in aqueous media, and consequently spectra of M 12-NSE-labelled preparations are free of “liquid lines”.At least two types of spectra may be obtained when ox brain microsomes are spin labelled with M 12-NSE, indicating the presence of two distinct binding sites. At one site the spin label is relatively unrestricted and gives rise to an isotropic spectrum. A second spectrum, which is obtained from spin label at another site, is similar to that which is observed after incorporation of M 12-NSE into phospholipid bilayers. This suggests that this latter site is within the core of the microsomal membrane.The two binding sites differ in their affinity for the spin probe. The low affinity site is both more abundant in crude preparations and is more easily removed by detergent treatment; spin labels at this site produce isotropic spectra. The high affinity sites are fewer in number and produce broad spectra. In addition these high affinity sites increase in concentration as the enzyme undergoes purification.The two sites are quite distinct in their sensitivity to ascorbic acid, the low affinity site showing a considerably greater rate of reduction by this agent.This study also demonstrates that the delipidation effects of sodium dodecyl sulfate and sodium deoxycholate on $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase-enriched}$ microsomes from ox brain are not identical.It is suggested that the two spin probe binding sites represent two different lipid domains, one of which is very closely associated with the $\text{(}\text{Na}{}^{\mathrm{+}}\text{+}\text{K}{}^{\mathrm{+}}\text{)-}\text{ATPase}$ enzyme and may reflect a protein-directed phospholipid specificity for this enzyme.     

Comparative study of Bifidobacteriumanimalis, Escherichiacoli, Lactobacilluscasei and Saccharomycesboulardii probiotic properties

The present work investigates some probiotic properties of four different microorganisms (Bifidobacterium animalis var. lactis BB-12, Escherichia coli EMO, Lactobacillus casei and Saccharomyces boulardii). In vitro and in vivo tests were carried out to compare cell wall hydrophobicity, production of antagonistic substances, survival capacity in the gastrointestinal tract of germ-free mice without pathological consequence, and immune modulation by stimulation of Küpffer cells, intestinal sIgA and IL-10 levels. In vitro antagonism against pathogenic bacteria and yeast was only observed for the probiotic bacteria B. animalis and L. casei. The hydrophobic property of the cell wall was higher for B. animalis and E. coli EMO, and this property could be responsible for a better ability to colonize the gastrointestinal tract of germ-free mice. Higher levels of sIgA were observed mainly for S. boulardii, followed by E. coli EMO and B. animalis, and only S. boulardii induced a significant higher level of IL-10. In conclusion, for a probiotic use, S. boulardii presented better characteristics in terms of immunomodulation, and B. animalis and L. casei for antagonistic substance production. The knowledge of the different probiotic properties could be used to choice the better microorganism depending on the therapeutic or prophylactic application.     

Annular and non-annular binding sites on the (Ca2+ + Mg2+)-ATPase

Quenching of the fluorescence of the $\text{(}\text{Ca}{}^{\mathrm{2+}}\text{+}\text{Mg}{}^{\mathrm{2+}}\text{)-}\text{ATPase}$ purified from muscle sarcoplasmic reticulum can be used to measure relative binding constants of hydrophobic compounds to the phospholipid-protein interface. We show that the binding constant for cholesterol is considerably less than that for phosphatidylcholine, so that cholesterol is effectively excluded from the phospholipid annulus around the ATPase. However, dibromocholestan-3β-ol causes quenching of the fluorescence of the ATPase, and so has access to other, non-annular sites. We suggest that these non-annular sites could be at protein/protein interfaces in ATPase oligomers. Oleic acid can bind at the phospholipid/protein interface, although its binding constant is less than that for a phosphatidylcholine, and it can also bind at the postulated non-annular sites. The effects of these compounds on the activity of the ATPase depend on the structure of the phospholipid present in the systems.     

Comparison of parameters estimated from A/Ci and A/Cc curve analysis

The parameters estimated from traditional A/C _i curve analysis are dependent upon some underlying assumptions that substomatal CO₂ concentration (C _i) equals the chloroplast CO₂ concentration (C _c) and the C _i value at which the A/C _i curve switches between Rubisco- and electron transport-limited portions of the curve (C _i-t) is set to a constant. However, the assumptions reduced the accuracy of parameter estimation significantly without taking the influence of C _i-t value and mesophyll conductance (g _m) on parameters into account. Based on the analysis of Larix gmelinii’s A/C _i curves, it showed the C _i-t value varied significantly, ranging from 24 Pa to 72 Pa and averaging 38 Pa. t-test demonstrated there were significant differences in parameters respectively estimated from A/C _i and A/C _c curve analysis (p<0.01). Compared with the maximum ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) carboxylation rate (V_cmax), the maximum electron transport rate (J_max) and J_max/V_cmax estimated from A/C _c curve analysis which considers the effects of g _m limit and simultaneously fits parameters with the whole A/C _c curve, mean V_cmax estimated from A/C _i curve analysis (V_cmax-C _i) was underestimated by 37.49%; mean Jmax estimated from A/C _i curve analysis (J_max-C _i) was overestimated by 17.8% and (J_max-C _i)/(V_cmax-C _i) was overestimated by 24.2%. However, there was a significant linear relationship between V_cmax estimated from A/C _i curve analysis and V_cmax estimated from A/C _c curve analysis, so was it J_max (p<0.05).