拉曼光谱法快速区分周围神经束性质

目的探索一种快速鉴别神经束性质的方法。方法取新西兰大白兔32只,放血处死后,在手术显微镜下暴露取脊神经前根、后根各3~5 mm,立即做冰冻横切片,片厚30μm,进行拉曼光谱观察。结果同类标本拉曼光谱重现性好,光谱特征基本相似。运动神经与感觉神经的拉曼光谱在1 088 cm-1、1 276 cm-1、1 439 cm-1等附近的拉曼振动峰相对强度存在明显差异,1276 cm-1处的峰值与1 439 cm-1处的峰值比反映了运动神经与感觉神经之间的微观结构差异。结论不同性质神经拉曼光谱具有各自的特征谱,依据光谱特征的不同来区分神经束性质是一种鉴别神经束性质的有效方法。     

周围神经显微结构的拉曼光谱和超光谱成像特征

目的:研究周围神经内部显微结构的显微拉曼光谱和超光谱成像特征。方法:取新西兰大白兔10只,解剖并获取其骶1脊髓前根和后根标本,随机选取各10例标本作厚度为30μm冷冻切片。用波长633 nm的激光扫描神经纤维断面;随机各取3例前根和后根标本作厚度为10μm冷冻切片,用超光谱成像系统采集标本的超光谱数据。每个断面对轴突和髓鞘各取15个感兴趣区域(regions of interest,ROI)进行分析。结果:周围神经纤维的拉曼光谱在550 cm-1、1080 cm-1、1280 cm-1、1440cm-1、1660 cm-1处有明显的拉曼散射,以1440 cm-1处最为显著;运动和感觉神经纤维的拉曼光谱相似;周围神经髓鞘与轴突的超光谱曲线有区别。结论:周围神经感觉与运动神经纤维的显微拉曼光谱和超光谱曲线相似,难以独立进行区分。超光谱成像技术可直接对周围神经髓鞘进行识别。     

应用拉曼光谱技术分析血红蛋白构象及与P50变化的相关性研究

目的比较世居平原汉族、急进高原汉族(进入高原3 d和7 d)和高原习服训练汉族(进入高原30 d)外周血红细胞拉曼光谱及P_(50)的差异,分析高原低氧环境对人血红蛋白结构及功能的影响。方法上述人群中各选择15例健康男性作为研究对象,抽取外周抗凝血样本,并分离红细胞,运用拉曼光谱进行检测及数据分析;采用红细胞悬液测定P_(50)值。结果与世居平原汉族比较,急进高原3 d及7 d后在1 341 cm~(-1)、1 375 cm~(-1)、1 585 cm~(-1)及1 638 cm~(-1)等位移处出现特征峰;高原习服训练30d后,上述谱带消失;世居平原汉族急进高原初期(进入高原3d和7d)P_(50)值随时间延长而升高,而习服训练后P_(50)值下降。结论平原汉族急进高原后血红蛋白结构改变及红细胞P_(50)上升,有利于血红蛋白对氧的释放,以满足机体在进入高原前期组织的供氧;而当习服后则又恢复。     

无创脉搏氧饱和度监测仪的临床应用

无创脉搏氧饱和度监测仪是 2 0世纪 80年代发展起来的一种非常有效的血氧水平的无创性连续监测血氧饱和度 (SpO2 )的方法。它是根据血红蛋白吸收特性设计的 ,可反应机体组织是否缺氧 ,缺氧程度 ,有助于及时发现低氧血症 ,积极寻找原因 ,并作出相应的处理。本文对国内护理杂志中报道的有关SpO2仪用于各种疾病病人监测的情况综述如下。1　SpO2 监测仪原理和使用方法氧合血红蛋白 (HbO2 )和还原血红蛋白 (RHb)的分子可以吸收不同波长的光线 ,即HbO2 吸收红外光较多 ,而RHb吸收红光较多 ,脉搏血氧饱和度仪正是运用这一差异 ,使用 6 6 0mm…     

高龄慢性肾脏病人群血清拉曼光谱评价体系建立

目的通过收集和检测健康人群血清,建立常用慢性肾脏病诊断标志物的血清拉曼光谱检测体系。方法收集2016年1月至2017年6月于南昌市第一医院就诊的高龄慢性肾脏病患者300例以及同龄健康者500例进行研究,将慢性肾脏病人群分为研究组,健康人群分为对照组。检测常规肾功能标志物及利用拉曼光谱分析,建立数学模型预测结果精度,进行拉曼光谱谱线分析,进行常规肾功能检查和拉曼光谱分析,统计分析诊断敏感度以及特异度。结果两组总蛋白、总胆红素、总胆固醇、低密度脂蛋白胆固醇、极低密度脂蛋白胆固醇、葡萄糖、肌酐以及三酰甘油PLS建模预测的RMSEP值和相关系数差异均无统计学意义(P0.05)。两组血清经拉曼光谱分析,其谱线均主要于544、724、933、1 004、1 127、1 219、1 368、1 442cm-1及1 607cm-1处呈现特征峰,研究组544、724、933、1 004、1 368、1 442、1 607cm-1处平均特征峰值强度均明显低于对照组,差异有统计学意义(P0.05),在1 127、1 219cm-1处特征峰值强度均明显高于对照组,差异有统计学意义(P0.05)。拉曼光谱分析血肌酐、尿素氮、血清胱抑素C阳性检出率均明显高于常规肾功能检查(P0.05),清蛋白指标检出结果两者差异无统计学意义(P0.05)。血清拉曼光谱诊断敏感度90.66%,特异度92.60%;GFR检查诊断敏感度81.33%,特异度88.20%,血清拉曼光谱分析诊断高龄慢性肾脏病敏感度及特异度均要明显高于GFR(P0.05)。结论血清拉曼光谱分析能发现早期慢性肾脏病,诊断敏感度和特异度均较高,对于评价高龄慢性肾脏病人群肾功能具有独特优势,在进一步验证并优化调整模型后可以在临床上广泛推广使用。     

支原体肺炎儿童与健康儿童血清拉曼光谱检测的差异性研究

目的 探讨血清拉曼光谱检测技术在支原体肺炎儿童与健康儿童的差异性。方法 收集商洛市中心医院2017年4～12月收治的支原体肺炎患儿血清100例作为实验组,选取同期健康儿童的血清100例作为对照组,使用全自动显微拉曼系统检测两组血清的拉曼光谱信号,对差异性进行分析。结果 与对照组相比,实验组血清在位移1 653.34 cm^-1处拉曼光谱峰发生了减弱,差异有统计学意义(t=2.137,P<0.05),在位移1 152.93和1 515.33 cm^-1处拉曼光谱峰得到了增强,差异有统计学意义(t=2.027和2.028,均P<0.05)。结论 初步研究表明支原体肺炎儿童与健康儿童血清拉曼光谱信号存在差异。     

碳氧血红蛋白及网织红细胞在新生儿溶血病诊断中的应用价值

目的探讨碳氧血红蛋白(COHb)联合网织红细胞(Ret)对新生儿溶血病(HDN)的诊断价值。方法选取我院2018年11月至2019年4月收治的286例HDN患儿,将其作为HDN组;选取同期于我院分娩的286例健康新生儿作为对照组。比较两组血清COHb、Ret水平;绘制受试者工作特征曲线(ROC),分析血清COHb、Ret及二者联合诊断HDN的价值,获得曲线下面积(AUC),明确最佳截断值、灵敏度及特异度。结果HDN组的血清COHb、Ret水平高于对照组(P<0.05)。ROC曲线提示,血清COHb、Ret单独诊断HDN的AUC分别为0.599、0.616,最佳截断值分别为1.308%、4.855%。COHb联合Ret诊断HDN的灵敏度为86.4%,特异度为75.2%。结论HDN患儿的血清COHb、Ret水平明显较高,且COHb联合Ret对HDN具有较高的诊断价值。     

拉曼光谱在妊娠糖尿病诊断中的应用价值

目的探讨拉曼光谱在妊娠糖尿病(GDM)中的应用价值。方法选取29名非孕体检健康者(正常对照组)、29例正常妊娠妇女(正常妊娠组)和42例GDM患者,建立拉曼光谱诊断GDM的方法。另选取78例GDM患者和70名体检健康者进行方法验证。采用正交偏最小二乘回归(OPLS)、主成分分析(PCA)-支持向量机(SVM)及PCA-隐含狄利克雷分布(LDA)3种数学模型对拉曼光谱结果进行分类,并筛选出特征峰。采用受试者工作特征(ROC)曲线评价3种模型的分类能力,筛选最优模型,并与口服葡萄糖耐量试验(OGTT)进行比较。结果GDM患者、正常对照者及正常妊娠妇女在1005.86、1034.47、1087.64和1128.39 cm^-1处均出现较明显的拉曼光谱峰。GDM组在1005.86、1034.47、1128.39和1343.69 cm^-1处的拉曼光谱峰与正常对照组及正常妊娠组有明显差异。OPLS模型对GDM组、正常对照组及正常妊娠组的区分能力最佳。采用OPLS模型区分拉曼光谱诊断GDM的敏感性为97.43%、准确度为95.27%,高于OGTT法的91.03%和93.92%;但特异性为92.86%,低于OGTT法的97.14%。结论拉曼光谱结合OPLS模型具有较好的敏感性、特异性和准确度,或可作为GDM筛查和诊断的有效方法。     

两种急性髓系白血病细胞的超微结构和拉曼光谱特征研究

目的:研究急性早幼粒细胞白血病(M3)和急性单核细胞白血病(M5)细胞的拉曼光谱特征,建立使用拉曼光谱非标记鉴别两种急性髓系白血病的新方法,为临床实验研究提供基础。方法:分别收集4例M3和3例M5患者的白血病细胞,使用Horiba Xplora拉曼光谱仪获取拉曼光谱,从每例患者采集30至50个白血病细胞光谱。结合应用主成份分析法(principle component analysis,PCA)、判别函数分析(discriminant function analysis,DFA)和系统聚类分析对两类细胞的光谱进行分析和建立诊断模型,进而对M3和M5细胞的光谱进行鉴别,应用交互验证方法对诊断模型进行验证,同时结合透射电子显微镜下白血病细胞超微结构分析拉曼光谱的特征。结果:M_3和M_5细胞的拉曼光谱差别显著,M_3细胞在波数622、643、757、852、1 003、1 033、1 117、1 157、1 173、1 208、1 340、1 551、1 581 cm~(-1)等处的谱峰强度明显大于M_5细胞;鉴别诊断建模的总体分类准确率达100%(233/233),交互验证的分类准确率达97%(226/233)。结论:拉曼光谱分析结果显示,M_3细胞的生物大分子水平显著高于M_5;根据PCA-DFA及聚类分析建立的拉曼光谱诊断模型能够准确区分上述2种急性髓细胞白血病细胞,其结果与白血病细胞超微结构相符。     

基于功能性近红外光谱成像技术探究舌三针对幕下脑卒中吞咽障碍患者皮质功能活动的影响

目的 采用功能性近红外光谱成像技术（fNIRS）探讨幕下脑卒中吞咽障碍患者的皮质功能状态与吞咽功能的相关性，并观察舌三针对该类患者皮质活动的影响。 方法 选取幕下脑卒中吞咽障碍患者30例，按照随机数字表法将其分为假针刺组和舌三针组，每组15例。采用fNIRS采集两组患者在静息态、针刺态(假针刺组为假针刺态)、电针态（假针刺组为假电针态）、针刺后静息态（假针刺组为假针刺后静息态）下的氧和血红蛋白（HbO2）的相对浓度变化（ΔHbO2）。采用改良Rankin量表（mRS）、渗漏误吸评分（PAS）、功能性经口摄食量表（FOIS）评估两组患者的整体功能残疾水平和吞咽功能。 结果 静息态下，两组患者的左侧初级运动皮质（r=0.550，P=0.002）、左侧背外侧前额叶皮质（r=0.585，P=0.001）和左侧前运动皮质（r=0.510，P=0.004）区域的平均ΔHbO2浓度与PAS评分呈中度正相关。针刺态下，舌三针组患者的右侧额下回（F=9.651，P=0.004）和左侧颞中回（F=3.343，P=0.029）区域的ΔHbO2浓度显著增加（P＜0.05），左侧躯体感觉皮质（F=4.948，P=0.035）和左侧初级运动皮质（F=4.742，P=0.038）区域的ΔHbO2浓度显著降低（P＜0.05）。 结论 舌三针可促使幕下脑卒中吞咽障碍患者的大脑皮质活动发生变化，这可能是改善吞咽障碍的潜在机制。     

Diode-array spectrophotometry for simultaneous measurement of hemoglobin pigments

A prototype oxygen saturation meter was used to measure the concentrations of deoxygenated hemoglobin (rHb), oxyhemoglobin (HbO2), carboxyhemoglobin (HbCO), methemoglobin (MetHb), and sulfhemoglobin (SHb) in 35 microliter blood. Simultaneous absorbance measurements at 535, 560, 577, 622, 636, and 670 nm permitted the composition of any hemoglobin pigment mixture to be determined more accurately, precisely and easily than before. The inclusion of 670 nm, where the hemoglobin pigments have low absorption coefficients, allowed correction for turbidity.     

Measuring percent oxygen saturation of hemoglobin, percent carboxyhemoglobin and methemoglobin, and concentrations of total hemoglobin and oxygen in blood of man, dog, and baboon

We used an automated four-wavelength spectrometer to measure the concentration of total hemoglobin, percent oxyhemoglobin, carboxyhemoglobin, and methemoglobin, and concentration of oxygen bound to hemoglobin in the blood of humans, dogs, and baboons under clinical and various experimental conditions. Measurements of total hemoglobin and methemoglobin with this simple method were comparable to those with standard spectrometric procedures. Carboxyhemoglobin measurements were comparable to those made with gas chromatography, and measurements of oxygen content were comparable to those made with the galvanic cell method. The new instrument is as accurate as the comparison methods used to evaluate it in all parameters, is reliable, and measurements take only 63 s per sample. In addition, it requires minimal operator training, infrequent need for calibration, and no sample preparation.     

Oscillatory oxido-reductive reaction of intracellular hemoglobin in human erythrocyte incubated with o-aminophenol

When human erythrocytes were incubated with o-aminophenol at pH 7.0 at 37 degrees C for 46 hours, intracellular oxyhemoglobin was completely oxidized to methemoglobin during the initial 6 hours, and methemoglobin formed was then reduced to oxyhemoglobin during the following 20 hours. This was demonstrated by the changes in absorption spectra of intracellular hemoglobin. Such oscillatory behavior of intracellular hemoglobin during reaction with o-aminophenol was explained by the fact that o-aminophenol has the ability to both oxidize oxyhemoglobin and reduce methemoglobin. In order to study the mechanism of oxido-reductive reactions of hemoglobin with aromatic reductants including o-aminophenol, the oxidation of ferrous hemoglobin and reduction of methemoglobin with various aromatic reductants such as o-aminophenol, 2-amino-4-methyl-phenol, 2-amino-5-methylphenol, and homogentisic acid were investigated under various conditions. It was found that oxyhemoglobin was oxidized by these aromatic compounds, and the oxidation rate was accelerated in the presence of inositol hexaphosphate, but was not affected in the presence of catalase and superoxide dismutase, except for the case with homogentisic acid. The oxidation of ferrous hemoglobin by these compounds did not proceed under anaerobic conditions. Methemoglobin was reduced by these aromatic compounds, and the reduction rate was much accelerated in the presence of inositol hexaphosphate, but was not affected in the presence of catalase and superoxide dismutase, except for the case with homogentisic acid. The reduction of methemoglobin by these compounds proceeded under anaerobic conditions, suggesting that ferric heme of hemoglobin reacts directly with aromatic reductants. On the basis of these results, the mechanism of oxido-reductive reaction of ferrous and ferric hemoglobin with aromatic reductants was proposed.     

STUDIES ON THE OXIDATION-REDUCTION OF HEMOGLOBIN AND METHEMOGLOBIN : II. THE OXIDATION OF HEMOGLOBIN AND REDUCTION OF METHEMOGLOBIN BY ANAEROBIC BACILLI AND BY STERILE PLANT TISSUE.

The oxidation-reduction systems of anaerobic bacteria manifest their action upon the blood pigments by marked deoxygenation of oxyhemoglobin, prompt reduction of methemoglobin to hemoglobin, and to a less marked degree oxidation of hemoglobin to methemoglobin. The action of sterile plant tissue upon oxyhemoglobin, hemoglobin, and methemoglobin has been studied. The oxidations and reductions of the blood pigments which are induced by sterile plant tissue are similar to the reactions which are brought about by pneumococci and by anaerobic bacteria.     

Methods for measuring plasma hemoglobin in micromolar concentration compared.

Of eight methods examined for measuring plasma hemoglobin in micromolar concentration, all exhibited acceptable linearity, reproducibility, and concurrence except when specimens were icteric or lipemic or contained methemoglobin or methemalbumin. Measurement of absorbance at 578 nm with an Allen correction permits precise assay of plasma oxyhemoglobin concentration as low as 0.01 g/L (1 mg/dL, 0.16 mumol/L), unaffected by hyperlipidemia or hyperbilirubinemia. Discrepancies between methods occurred in 11.6% of a consecutive series of 50 nonicteric patients' plasma specimens. Examination of absorption spectra is helpful when discrepancies are observed between methods. The presence of methemalbumin or methemoglobin in plasma is not recognized by methods that measure only oxyhemoglobin. Increased ceruloplasmin or beta-carotene does not significantly affect results.     

Determining methemoglobin in blood by zero-crossing-point first-derivative spectrophotometry

We determined methemoglobin in blood by zero-crossing-point first-derivative spectrophotometry. After lysis of erythrocytes, hemoglobin was converted into oxyhemoglobin and the first derivative spectrum was recorded between 405 and 425 nm. At the exact point where the first-derivative spectrum of oxyhemoglobin was zero ("zero-crossing point"), the first-derivative value of oxyhemoglobin and methemoglobin mixture was proportional to the methemoglobin concentration. The standard curve was linear for all proportions of methemoglobin. Within-assay precision (CV) was 3.4% for a 20% methemoglobin content. Correlation with results by the Evelyn and Malloy method was very good for high proportions of methemoglobin (greater than 10%), but the proposed technique was far better for low methemoglobin percentages because of its linearity, its high sensitivity, and its low detection limit.     

Chronic methemoglobinemia: Improving hemoglobin saturation monitoring during anesthesia

Methemoglobin interferes with the accuracy of pulse oximetry data. Methemoglobinemia is caused by many factors, both congenital and acquired. However, the increasing usage of dapsone, which converts hemoglobin to methemoglobin, is increasing the number of patients with methemoglobinemia. We present the case of a patient with dapsone-induced methemoglobinemia who was successfully treated with methylene blue, which converts methemoglobin back to hemoglobin. Methemoglobin interferes with the accurate pulse oximetric monitoring of oxyhemoglobin saturation [1—5]. Generally, in the presence of methemoglobin levels greater than 1 g’dL^-1, pulse oximeter readings above 85% underestimate the saturation of functional hemoglobin (the hemoglobin functioning normally with respect to oxygen); readings below 85% overestimate the saturation [2]. These inaccuracies are exaggerated as methemoglobin levels increase or functional hemoglobin saturation decreases [2]. In addition to other causes of methemoglobinemia, the spread of the HIV epidemic and the increasing number of HIV patients receiving dapsone (diaminodiphenylsulfone) as prophylactic treatment forPneumocystis carinii will expand the population of patients with clinical methemoglobinemia who require anesthesia for surgery [6-8]. Virtually all patients treated with dapsone will have levels of methemoglobin sufficient to interfere with pulse oximetric monitoring [7]. We present a case that illustrates these problems and emphasizes the importance of treating methemoglobinemia before the induction of anesthesia to ensure accurate intraoperative monitoring of oxyhemoglobin saturation.     

ON THE ANTIGENIC PROPERTIES OF HEMOGLOBIN

Sera produced by immunization with crystalline oxyhemoglobin react species-specifically with hemoglobin solutions. Evidence is presented that in this reaction the hemoglobin itself is the active substance. Conversion of oxyhemoglobin into methemoglobin, carbon-monoxy hemoglobin, or cyanhemoglobin does not alter the response to the precipitating immune serum. Not only the hemoglobin of homologous species, but also that of other species causes inhibition in greater or less degree of the precipitin reaction.     

PREPARATION OF DRIED HEMOGLOBIN WITHOUT LOSS OF ACTIVITY

The technique for freezing, drying, and preserving in vacuo which is in common use for plasma can be successfully applied to hemoglobin solutions when the hemoglobin is first deoxygenated to the extent of 99.7 per cent or more. In confirmation of Morrison and Hisey, the preliminary deoxygenation of the solution is found necessary to avoid formation of methemoglobin during drying. If a solution of oxyhemoglobin is frozen and dried, 20 to 30 per cent is changed to methemoglobin. Deoxygnated hemoglobin dried and preserved in vacuo retained all its oxygenbinding activity for 180 days, when stored at temperatures from 4° to 30°C. Storage at 38°C. for 92 days, or at 56° for 7 days, caused no loss in activity. The dried hemoglobin had a foam structure which caused it to dissolve immediately upon contact with water. Deoxygnated hemoglobin in the dry state was partly converted to methemoglobin by even momentary contact with oxygen. When, however, the deoxygnated hemoglobin was dissolved before it was exposed to air, the hemoglobin in solution was relatively stable, and could be stored for months at 4° in contact with air without significant loss of activity.     

PREPARATION OF HEMOGLOBIN SOLUTIONS FOR INTRAVENOUS INFUSION

A procedure has been detailed for the preparation of sterile non-pyrogenic solutions of oxyhemoglobin which have the approximate protein content and electrolyte composition of plasma. Large volumes of solution can be rapidly prepared, with 95 to 98 per cent of the hemoglobin in the active form capable of combining with oxygen. The solutions contain no particulate matter; 95 per cent of total blood lipids are removed. Solutions stored at 4°C. showed no conversion of hemoglobin to methemoglobin over a period of 2½ months; over a 6 month period a small and variable amount of methemoglobin may be formed.