Immunoassays at a quartz-liquid interface: theory, instrumentation and preliminary application to the fluorescent immunoassay of human immunoglobulin G

The theoretical basis and instrumental requirements of an optical detection technique for monitoring antibody-antigen reactions at a quartz-liquid interface are described. The antibody is covalently immobilized on the optical surface of a planar, fused-quartz waveguide and reacted with antigen solution. A light beam is internally reflected within the waveguide and penetrates into the solution only a fraction of the wavelength of the incident light. This is the evanescent wave which interacts optically with the growing number of antigen-antibody complexes but minimally with the bulk solution. A two-site immunofluorescent assay for human IgG measurement is described using fluorescein as the label. The assay detection limit is approximately 0.8 micrograms/ml and individual fluorescence measurements are completed within 10 min. It is expected that this evanescent wave immunoassay should have wide applicability in both routine and research fields.     

Intraoperative awareness due to malfunction of a Siemens 900B ventilator

A case of intraoperative awareness during a thoracotomy is described. The patient's recall coincided with an intraoperative period during which a Siemens 900B ventilator and a Siemens 952 isoflurane vaporiser were used. Subsequent assessment of this equipment with an anaesthetic agent analyzer revealed that, at the ventilator settings which had been used, the delivered anaesthetic vapour concentration varied greatly from the vaporizer settings. This problem eventually was traced to a malfunctioning inlet control valve on the ventilator. This complication may have been prevented if the end-tidal anaesthetic concentration had been monitored intraoperatively.     

Is the IV obstructed or infiltrated? A simple clinical test

Objective. The objective of our study was to determine if clinical observation of pressure-flow relationships (PFR) can differentiate between partial external obstruction (obstruction) and infiltration as a cause of poor performance of gravity-fed infusions.Methods. A total of 24 patients with functional intravenous cannulae in situ had obstruction simulated by the application of a tourniquet proximal to the cannula. The change in flow (F) for a discrete change in pressure (P) was determined in each case by counting drop rates at two different elevations of the fluid reservoir level, 10 cm apart. The same process was repeated in 15 patients in whom the cannula was in an extra vascular location (infiltration). Three sizes of cannula—16-gauge, 18-gauge, and 20-gauge—were examined, with equal distribution of sizes in each group. The effect on flow rates of inflating a blood pressure (BP) cuff proximally on the cannulated limb was assessed. The ratio P/F is the total resistance of the infusion system, and by subtracting known values for resistance of infusion tubing and cannula, the venous or tissue resistance was calculated.Results. There was a statistically significant difference between the change in flow for obstructed compared with infiltrated cannulae for the same change in pressure for each cannula size. The mean venous resistance was 23 mm Hg/L/hr, while that of tissue was 280 mm Hg/L/hr, with no overlap between groups. There was no effect on flow rate with blood pressure cuff inflation in the infiltrated group whereas flow progressively fell in the obstructed group.Conclusions. Clinical observation of PFRs in poorly functioning gravity-fed IV infusions can assist in detecting infiltration as a cause. Inflation of a blood pressure cuff will further impair flow where the cannula is intravascular, but will have no effect in an extravascular location.     

The estimation of sleep quality in different stages and cycles of sleep

Dream content in NREM and REM sleep correlates with the subjective experience of having slept immediately before awakening. The estimation of depth of sleep depends on the quality of the NREM sleep stages. The presence of dreaming in a given sleep stage is more important for the subjective experience of having slept than the duration of the sleep episode before the awakening. Neurotic insomniac patients more often deny mental activity when awoken from NREM and REM sleep, than do healthy subjects. These data suggest that spontaneous awakenings in different sleep stages, especially in the first sleep cycle, correlate with the insomniac's tendency to underestimate sleep duration and quality.     

EGFR与HER2对非小细胞肺癌的预后观察

目的:探讨传统的非小细胞肺癌预后因素与表皮生长因子等生物学新预后因素结合对非小细胞肺癌的预后作用.方法:复习116例非小细胞肺癌手术病例临床病理资料及随访资料,观察常规HE染色切片判断血管浸润及淋巴管浸润,用免疫组化法测定病灶的EGFR、HER2的表达,再用Cox模型进行生存分析.结果:NSCLC组EGFR、HER2、BVI、LVI的阳性表达率分别为42.24%、43.10%、44.83%、31.90%.BVI阴、阳性组术后生存期比较P=0.006,无瘤生存期比较P=0.001;LVI阴、阳性组术后生存期、无瘤生存期比较P分别为0.239和0.048;EGFR阴、阳性组术后生存期、无瘤生存期比较P分别为0.117及0.217;HER2阴、阳性组术后生存期、无瘤生存期比较P分别为0.073和0.053.进入影响生存期多因素模型的为N分期、HER2、TNM分期及手术方式(P分别为0.006、0.01、0.019和0.022).结论:13项临床病理和生物因素结合起来进行多变量Cox回归分析,影响生存期的因素为:N分期、HER2、TNM分期及手术方式.影响无瘤生存期的因素为:BVI、TNM分期和N分期.     

Changes in rapidly extracted auditory evoked potentials during tracheal intubation

BACKGROUND: One of the problems encountered in assessment of the hypnotic level during anesthesia is the extraction of a consistent and reliable measure online and close to real time. Hemodynamic parameters such as heart rate and blood pressure are not, at least with the traditional single parameter versus time presentation, adequate for ensuring an optimal level of anesthesia, especially when using neuromuscular blocking agents (NMBA). In the literature, it has been demonstrated that auditory evoked potentials (AEP) are able to provide two aspects relevant to determining level of anesthesia: firstly, they have identifiable anatomical significance and, secondly, their characteristics reflect the way the brain perceives a stimulus. METHODS: The aim of this study was to evaluate the AEP index based on a system identification model, the autoregressive model with exogenous input (ARX-model), and to compare it to the classical method, the moving time average (MTA). The ARX enables the extraction within 15-25 sweeps, depending on the signal-to-noise ratio (SNR), whereas MTA typically needs 250-500 sweeps. The hypothesis of the present study was that since the ARX-model extracts the AEP faster than the MTA-model, the former should be able to detect changes during the brief, intense stimulus of endotracheal intubation. Twelve female patients scheduled for gynecological surgery were included in the study. Anesthesia was initiated with thiopentone and maintained with isoflurane and alfentanil. The AEP was mapped into an index (AEP-index) normalized to 100 when the individual was awake and decreasing to an average of 25 during thiopentone induced anaesthesia. The results were compared to those obtained by MTA-extracted AEP. RESULTS: During tracheal intubation 9 patients showed an increase in the ARX-extracted AEP-index larger than 15, and 6 of these patients showed an increase larger than 25 (mean increase=33, SD=18). The MTA-extracted AEP-index showed only one patient with an increase larger than 15. The ARX-extracted AEP changed significantly faster than the MTA-extracted AEP. CONCLUSION: The ARX-extracted AEP-index increases during tracheal intubation. There is a significant difference between the ARX-extracted AEP and the traditional MTA-extracted AEP, in terms of response time. In order to trace short-lasting changes in the hypnotic level by AEP, the AEP should be extracted by a method with a fast response such as the ARX-model.     

Histopathologic parameters of prognosis in cervical cancer – a review

Apart from clinical stage and lymph node status, acknowledged to be among the most powerful predictors of outcome in cervical cancer, the determination of prognosis and thereby the need for adjuvant therapy in surgically treated patients currently relies on a variety of histopathologic factors. The role of many of these is controversial. This may be because histopathology is genuinely lacking in sensitivity for predicting tumor behavior in vivo. There is, however, wide variation in histopathologic definitions and criteria. This is probably the major reason for both the lack of reproducibility in the reporting of certain factors and in their diminished value in predicting behavior. Tumor type, grade, vascular invasion, pattern of invasion, and depth are all extremely important prognostic indicators when used individually or as a part of a scoring system.     

血管内皮生长因子与大肠癌侵袭转移的相关性研究

目的:探讨血管内皮生长因子(VEGF)基因在大肠癌组织中的表达及其与大肠癌发生转移的关系。方法:采用定量逆转录聚合酶链式反应(QRT-PCR)方法,检测45例结直肠癌手术切除标本的癌和切端结肠组织VEGFmRNA的转录水平,同时用免疫组化方法检测VEGF的蛋白表达水平。结果:大肠癌组织中VEGFmRNA及其蛋白的表达阳性率明显高于切端结肠组织。大肠癌组织中VEGFmRNA转录水平及蛋白表达水平与肿瘤的浸润程度、淋巴结转移、Dukes’分期呈明显的正相关(P<0.01),与肿瘤的分化程度等无显著相关性(P>0.05)。结论:VEGF在大肠癌浸润和转移过程中发挥重要作用,肿瘤血管生成与大肠癌浸润和转移关系密切。VEGF可能具有预测大肠癌转移的作用。     

风门穴与肺俞穴针刺安全深度及角度的应用解剖研究

采用钢针标定法和层次解剖法,在46具成年人尸体上,研究风门穴与肺俞穴的解剖结构和针刺深度及角度。结果显示:向下直刺的解剖结构依次是皮肤、浅筋膜、斜方肌、菱形肌、上后锯肌、竖脊肌、肋提肌、肋间内膜、胸内筋膜、肋胸膜,向下直刺的平均危险深度,风门穴为49.51 mm,肺俞穴为44.88 mm;向外下斜刺,当针体与矢状面夹角在20~25°时,危险深度最小;向内下斜刺,当针体与矢状面夹角大于20°时,比较安全。