Handheld analyzer with on-chip molecularly-imprinted biosensors for electrical detection of propofol in plasma samples.

This paper proposes a novel handheld analyzer with disposable lab-on-a-chip technology for the electrical detection of the anesthetic propofol in human plasma samples for clinical diagnoses. The developed on-chip biosensors are based on the conduction of molecularly imprinted polymers (MIPs) that employ label-free electrical detection techniques. Propofol in total intravenous anesthesia is widely used with a target-controlled infusion system. At present, the methods employed for detecting blood propofol concentrations in hospitals comprise high-performance liquid chromatography and ion mobility spectrometry. These conventional instruments are bulky, expensive, and difficult to access. In this study, we developed a novel plastic microfluidic biochip with an on-chip anesthetic biosensor that was characterized for the rapid detection of propofol concentrations. The experimental results revealed that the response time of the developed propofol biosensors was 25s. The specific binding of an MIP to a nonimprinted polymer (NIP) reached up to 560%. Moreover, the detection limit of the biosensors was 0.1µg/mL, with a linear detection range of 0.1-30µg/mL. The proposed disposable microfluidic biochip with an on-chip anesthetic biosensor using MIPs exhibited excellent performance in the separation and sensing of propofol molecules in the human plasma samples. Compared with large-scale conventional instruments, the developed microfluidic biochips with on-chip MIP biosensors present the advantages of a compact size, high selectivity, low cost, rapid response, and single-step detection.

Enhanced anesthetic propofol biochips by modifying molecularly imprinted nanocavities of biosensors.

This paper presents enhanced performance of anesthetic propofol biosensors by modifying molecularly imprinted nanocavities of biosensors. In this work, the relationship between molecularly imprinted nanocavities and performance of molecularly imprinted polymer (MIP) films is investigated. The morphological control of imprinted nanocavities on molecularly imprinted biosensors is done by adjusting polymer composition and polymerization process. The newly developed MIP biosensors are characterized using our developed microfluidic biochips and optical microsystems. Experimental results show that the sizes of molecularly imprinted nanocavities were reduced to 10 to 14 nm from 10 to 25 nm. The roughness of the MIP film surface was reduced to 2.5 nm from 6.6 nm. Smaller imprinted nanocavities have better molecular separation performance. The specificity and linearity of the anesthetic biosensors could be enhanced by adjusting morphology of imprinted nanocavities. The linearity and the sensitivity of the microfluidic biochip with an improved on-chip MIP biosensor have been enhanced from 0.9341 to 49.5 mV/mm².ml/µg, respectively, to 0.9782 and 176.9 mV/mm².ml/µg. The anesthetic propofol biosensor presented in this study is applicable to numerous fluidic-based disposable biochips.

A disposable microfluidic biochip with on-chip molecularly imprinted biosensors for optical detection of anesthetic propofol.

This paper presents a disposable microfluidic biochip with on-chip molecularly imprinted biosensors for optical detection of anesthetic propofol. So far, the methods to detect anesthetic propofol in hospitals are liquid chromatography (LC), high-performance liquid chromatography (HPLC), and gas chromatography-mass spectroscopy (GC-MS). These conventional instruments are bulky, expensive, and not ease of access. In this work, a novel plastic microfluidic biochip with on-chip anesthetic biosensor has been developed and characterized for rapid detection of anesthetic propofol. The template-molecule imprinted polymers were integrated into microfluidic biochips to be used for detecting anesthetic propofol optically at 655 nm wavelength after the reaction of propofol with color reagent. Experimental results show that the sensitivity of the microfluidic biochip with on-chip molecularly imprinted polymers (MIPs) biosensor is 6.47 mV/(ppm mm(2)). The specific binding of MIP to non-imprinted polymer (NIP) is up to 456%. And the detection limit of the microsystem is 0.25 ppm with a linear detection range from 0.25 to 10 ppm. The disposable microfluidic biochip with on-chip anesthetic biosensor using molecularly imprinted polymers presented in this work showed excellent performance in separation and sensing of anesthetic propofol molecules. While compared to large-scale conventional instruments, the developed microfluidic biochips with on-chip MIP biosensors have the advantages of compact size, high sensitivity, high selectivity, low cost, and fast response.

Synergistic anti-cancer effect of baicalein and silymarin on human hepatoma HepG2 Cells.

This study investigated the effect of baicalein, silymarin, and their combination, on two human liver-derived cell lines, HepG2 (hepatocellular carcinoma) and Chang liver (non-tumor liver cells). It was found that 6.75 microg/ml baicalein or 100 microg/ml silymarin alone significantly inhibited the growth of HepG2. When baicalein was used in combination with silymarin on HepG2, an additive effect at 24 h and a synergistic effect at 48 h were observed. The viability at 48 h was 85.62% from 6.75 microg/ml baicalein treatment; but the viability reduced to 49.67%, 38.56%, and 19.61% when 25, 50, and 100 microg/ml silymarin respectively, was added to the treatment. By contrast, each treatment had little or no effect on Chang liver. Compared to treatment of baicalein or silymarin alone on HepG2, combination of both drugs synergistically increased the percentages of cells in G0/G1 phase and decreased those in S-phase, which were associated with up-regulation of Rb, p53, p21(Cip1) and p27(Kip1) and down-regulation of cyclin D1, cyclin E, CDK4 and phospho-Rb. The results indicate that the combination of baicalein and silymarin eradicates tumor cells efficiently, has minimal deleterious effects to the surrounding normal cells, and offers mechanistic insight for further exploitation of HCC treatment.

Postoperative residual curarization: clinical observation in the post-anesthesia care unit.

BACKGROUND: Neuromuscular blocking agents (NMBAs) are widely used during the induction and maintenance of anesthesia. Postoperative residual curarization (PORC) following the use of NMBAs still occurs even though intermediate-acting NMBAs were used. Train-of-four (TOF) stimulation is used to quantify the degree of neuromuscular blockade. The TOF ratio of 0.7 in the adductor pollicis muscle was associated with normal respiratory function. Pharyngeal function returned to normal while the TOF ratio reached 0.9. The aim of this study was to survey the PORC in the post-anesthesia care unit (PACU). METHODS: In this observational study, 308 patients who received general anesthesia with NMBAs were enrolled. Residual curarization was evaluated using the TOF-Watch acceleromyograph upon arrival in the PACU. Three consecutive TOF stimulations were applied and recorded at 15-second intervals. Two thresholds of TOF ratios (0.9 and 0.7) were used to assess the presence of residual curarization. RESULTS: TOF ratios less than 0.7 and 0.9 were observed in 15 (5%), and 97 (31%) patients, respectively. The differences of the TOF ratios between the male and female patients were significant (p = 0.014). In terms of weight, the differences between the patients with ratios > 0.9 and < or = 0.9 were significant (p = 0.013). There were 67, 49, 15, and three patients who received reversal medication in the > 0.9 group, < or = 0.9 and > 0.7 group, and < or = 0.7 group, respectively. The differences of the TOF ratios between the patients who received and those who did not receive reversal medication were not significant (p = 0.91). CONCLUSION: PORC is still a clinical problem in the modern PACU. Objective neuromuscular monitoring needs to be performed to ensure patient safety.

Dexamethasone effectively reduces postoperative nausea and vomiting in a general surgical adult patient population.

BACKGROUND: Postoperative nausea and vomiting (PONV) is still a common and major complication for surgical patients, which may delay post-anesthetic care unit discharge, prolong hospital stay and thus increase the cost of hospitalization. It is understood that PONV is a multi-factorial outcome and occurs more often with general anesthesia than with other anesthetic methods. Prophylactic administration of antihistamines, antidopaminergics, anticholinergics, phenothiazines, serotonin antagonist, steroids and even acupuncture has been shown to be effective. However, expenses and side effects of these agents have also been a concern for clinical doctors. The aim for this prospective study was to find an agent that is cost effective and side effect free (or at least with a low incidence of side effects) for the prevention of PONV. METHODS: A total of 700 adult surgical patients who planned to have surgery under general anesthesia were enrolled in this double-blinded, randomized and placebo-controlled study. Group P received the placebo (0.9% normal saline 2 ml) and Group D received 10 mg dexamethasone intravenously right before the induction of anesthesia. RESULTS: We found that during the postoperative period of 1-8 h, patients in Group D reported a lower incidence of PONV (24%) than those in Group P (39%, p < 0.001). Patients in Group D also requested less rescue anti-emetic (17%) than those in Group P (30%, p < 0.05). The same phenomenon was also noted in the 8-to-24-hour interval (PONV 4% vs. 12%, p < 0.05 and rescue anti-emetic 3% vs. 9%, p < 0.05 in Group D vs. Group P, respectively.) CONCLUSIONS: We conclude that the prophylactic intravenous administration of 10 mg dexamethasone immediately before the induction of anesthesia is effective in preventing PONV in the general surgical adult patient population.

Application of wire-guided endobronchial blocker for one-lung ventilation in patient with tracheostomy--a case report.

One-lung ventilation (OLV) with a double-lumen endotracheal tube or Univent may be achieved difficulty in morbidly obese, mouth opening-limited or critically ill patients. Now, a new fiberoptically directed wire-guided endobronchial blocker (WEB) can be applied for these conditions. We report the use of a new endobronchial blocker in a pharyngeal cancer patient after pharyngectomy. The original 10# Shiley endotracheal tube was exchanged with reinforced cuffed tracheal tube. Then we use the WEB to achieve OLV. The WEB was guided by a loop, and through the appropriate position of left main bronchus by pediatric fiberoptic bronchoscope. Finally, OLV was accomplished smoothly with combination of a non-kinking endotracheal tube and a WEB.

Delayed hypoxemia after bone cement insertion during total hip replacement under spinal anesthesia--a case report.

We report a case of delayed hypoxemia in an aged healthy male patient, which developed 2 hours after cementation of the prosthesis in total hip replacement (THR) under spinal anesthesia. The patient was doing well throughout the operation but unfortunately, progressive tachypnea was noted 1 h after he was transferred to the recovery room (i.e. 2 h after the application of bone cement into the femur). An hour further, distinct wheeze was heard bilaterally on auscultation, which signified bronchospasm. Arterial blood gases analysis revealed a low PaO2 of 71 mmHg and a decrease of oxygen saturation to 91% with supplement of fractional oxygen of 35%. Aerosolization of bronchodilator with terbutaline was administered and supplemental fractional oxygen was increased to 50%. Although wheezing soon subsided, tachypnea and desaturation persisted. He was then transferred to the surgical intensive care unit for further management. Ventilation-perfusion lung scan was performed, which was suggestive of multiple pulmonary embolism.

Stroke after intraaortic balloon counterpulsation associated with mobile atheroma in thoracic aorta diagnosed using transesophageal echocardiography.

We describe a patient who developed embolic stroke after coronary artery bypass grafting (CABG) associated with intraaortic balloon pump (IABP) insertion. Intraoperative transesophageal echocardiography (TEE) revealed marked irregular mass and disruption of the intimal surface of the thoracic aorta with overlying shaggy echogenic material on the intimal surface of the descending thoracic aortic lumen. This case of stroke after IABP insertion suggested that the balloon inflation fragmented some mobile components on the inner surface of the aorta, and this floating debris entered the systemic circulation. TEE might be able to predict the risk of stroke in such a patient.