The Utilization of Optically Induced Dielectrophoresis (ODEP)-Based Cell Manipulation in a Microfluidic System for the Purification and Sorting of Circulating Tumor Cells (CTCs) with Different Sizes

The analysis of circulating tumor cells (CTCs) at the molecular level holds great promise for several clinical applications. For this goal, the harvest of high-purity, size-sorted CTCs with different subtypes from a blood sample are important. For this purpose, a two-step CTC isolation protocol was proposed, by which the immunomagnetic beads-based cell separation was first utilized to remove the majority of blood cells. After that, an optically induced dielectrophoresis (ODEP) microfluidic system was developed to (1) purify the CTCs from the remaining magnetic microbeads-bound blood cells and to (2) sort and separate the CTCs with different sizes. In this study, the ODEP microfluidic system was designed and fabricated. Moreover, its optimum operation conditions and performance were explored. The results exhibited that the presented technique was able to purify and sort the cancer cells with two different sizes from a tested cell suspension in a high-purity (93.5% and 90.1% for the OECM 1 and HA22T cancer cells, respectively) manner. Overall, this study presented a technique for the purification and sorting of cancer cells with different sizes. Apart from this application, the technique is also useful for other applications in which the high-purity and label-free purification and sorting of cells with different sizes is required.

Recent Progress in Enhanced Cancer Diagnosis, Prognosis, and Monitoring Using a Combined Analysis of the Number of Circulating Tumor Cells (CTCs) and Other Clinical Parameters

Analysis of circulating tumor cells (CTCs) holds promise to diagnose cancer or monitor its development. Among the methods, counting CTC numbers in blood samples could be the simplest way to implement it. Nevertheless, its clinical utility has not yet been fully accepted. The reasons could be due to the rarity and heterogeneity of CTCs in blood samples that could lead to misleading results from assays only based on single CTC counts. To address this issue, a feasible direction is to combine the CTC counts with other clinical data for analysis. Recent studies have demonstrated the use of this new strategy for early detection and prognosis evaluation of cancers, or even for the distinguishment of cancers with different stages. Overall, this approach could pave a new path to improve the technical problems in the clinical applications of CTC counting techniques. In this review, the information relevant to CTCs, including their characteristics, clinical use of CTC counting, and technologies for CTC enrichment, were first introduced. This was followed by discussing the challenges and new perspectives of CTC counting techniques for clinical applications. Finally, the advantages and the recent progress in combining CTC counts with other clinical parameters for clinical applications have been discussed.

Development of an Optically Induced Dielectrophoresis (ODEP) Microfluidic System for High-Performance Isolation and Purification of Bacteria

For the rapid detection of bacteria in a blood sample, nucleic acid amplification-based assays are believed to be promising. Nevertheless, the nucleic acids released from the dead blood cells or bacteria could affect the assay performance. This highlights the importance of the isolation of live bacteria from blood samples. To address this issue, this study proposes a two-step process. First, a blood sample was treated with the immuno-magnetic microbeads-based separation to remove the majority of blood cells. Second, an optically induced dielectrophoresis (ODEP) microfluidic system with an integrated dynamic circular light image array was utilized to further isolate and purify the live bacteria from the remaining blood cells based on their size difference. In this work, the ODEP microfluidic system was developed. Its performance for the isolation and purification of bacteria was evaluated. The results revealed that the method was able to harvest the live bacteria in a high purity (90.5~99.2%) manner. Overall, the proposed method was proven to be capable of isolating and purifying high-purity live bacteria without causing damage to the co-existing cells. This technical feature was found to be valuable for the subsequent nucleic-acid-based bacteria detection, in which the interferences caused by the nontarget nucleic acids could be eliminated.

Evaluation of Platelet Alloimmunization by Filtration Enzyme-Linked Immunosorbent Assay

The current methods for detecting antiplatelet antibodies are mostly manual and labor-intensive. A convenient and rapid detection method is required for effectively detecting alloimmunization during platelet transfusion. In our study, to detect antiplatelet antibodies, positive and negative sera of random-donor antiplatelet antibodies were collected after completing a routine solid-phase red cell adherence test (SPRCA). Platelet concentrates from our random volunteer donors were also prepared using the ZZAP method and then used in a faster, significantly less labor-intensive process, a filtration enzyme-linked immunosorbent assay (fELISA), for detecting antibodies against platelet surface antigens. All fELISA chromogen intensities were processed using ImageJ software. By dividing the final chromogen intensity of each test serum with the background chromogen intensity of whole platelets, the reactivity ratios of fELISA can be used to differentiate positive SPRCA sera from negative sera. A sensitivity of 93.9% and a specificity of 93.3% were obtained for 50 μL of sera using fELISA. The area under the ROC curve reached 0.96 when comparing fELISA with the SPRCA test. We have successfully developed a rapid fELISA method for detecting antiplatelet antibodies.

Using a continuous electrocardiographic patch with heart rhythm analysis in the subacute stage of aneurysmal subarachnoid hemorrhage: The feasibility verification

OBJECTIVE

Continuous cardiac monitoring on patients with aneurysmal subarachnoid hemorrhage (aSAH) is difficult out of intensive care unit (ICU) in the subacute stage. Therefore, we verified the feasibility of a novel electrocardiography (ECG) patch device to record long-term heart rhythm.

METHODS

The ECG patches were applied on aSAH patients during their stay in general ward. Any types of significant arrythmia were identified, and heart rate variability (HRV) measures were calculated in time and frequency domains. We analyzed the correlation between heart rhythm with Hunt and Hess scale and modified Fisher scale as well as the occurrence of secondary complications.

RESULTS

Twenty-six patients used the devices on median day 6 after aSAH onset, with put on and take down time average as 137 s and 45 s, respectively. Mean record time was 221.7 h, and no adverse event presented within the period. Hunt and Hess II/III subgroup had higher percentage of HRV high frequency band than IV/V subgroup (9.1 % vs 3.5 %, p = 0.043), whereas ultra low frequency band presented more in the later subgroup (50.4 % vs 61.4 %, p = 0.035). The very low frequency percentage significantly decreased (p = 0.025) at an average of 3 days prior to the occurrence of secondary complications compared to the days without complications.

CONCLUSION

For aSAH patients in general ward during subacute stage, the ECG patch is a safe and feasible tool. The correlation of long-term heart rhythm with prognosis is worthy to be investigated on larger sample size using this device in the future.

Inherent Bioelectrical Parameters of Hundreds of Thousands of Single Leukocytes Based on Impedance Flow Cytometry

As label-free biomarkers, bioelectrical properties of single cells have been widely used in hematology analyzers for 3-part differential of leukocytes, in which, however, instrument dependent bioelectrical parameters (e.g., DC/AC impedance values) rather than inherent bioelectrical parameters (e.g., diameter D_c , specific membrane capacitance C_sm and cytoplasmic conductivity σ_cy ) were used, leading to poor comparisons among different instruments. In order to address this issue, this study collected inherent bioelectrical parameters from hundreds of thousands of white blood cells based on a home-developed impedance flow cytometry with corresponding 3-part differential of leukocytes realized. More specifically, leukocytes were separated into three major subtypes of granulocytes, monocytes and lymphocytes based on density gradient centrifugation. Then these separated cells were aspirated through a constriction-microchannel based impedance flow cytometry where inherent bioelectrical parameters of D_c , C_sm and σ_cy were quantified as 9.8 ± 0.7 μm, 2.06 ± 0.26 μF/cm² , and 0.34 ± 0.05 S/m for granulocytes (n_cell = 134 829); 10.4 ± 1.0 μm, 2.45 ± 0.48 μF/cm² , and 0.42 ± 0.08 S/m for monocytes (n_cell = 40 226); 8.0 ± 0.5 μm, 2.23 ± 0.34 μF/cm² , and 0.35 ± 0.08 S/m for lymphocytes (n_cell = 129 193). Based on these inherent bioelectrical parameters, neural pattern recognition was conducted, producing a high "classification accuracy" of 93.5% in classifying these three subtypes of leukocytes. These results indicate that as inherent bioelectrical parameters, D_c , C_sm and σ_cy can be used to electrically phenotype white blood cells in a label-free manner.

Energy Efficiency of Inference Algorithms for Clinical Laboratory Data Sets: Green Artificial Intelligence Study

Background

The use of artificial intelligence (AI) in the medical domain has attracted considerable research interest. Inference applications in the medical domain require energy-efficient AI models. In contrast to other types of data in visual AI, data from medical laboratories usually comprise features with strong signals. Numerous energy optimization techniques have been developed to relieve the burden on the hardware required to deploy a complex learning model. However, the energy efficiency levels of different AI models used for medical applications have not been studied.

Objective

The aim of this study was to explore and compare the energy efficiency levels of commonly used machine learning algorithms—logistic regression (LR), k-nearest neighbor, support vector machine, random forest (RF), and extreme gradient boosting (XGB) algorithms, as well as four different variants of neural network (NN) algorithms—when applied to clinical laboratory datasets.

Methods

We applied the aforementioned algorithms to two distinct clinical laboratory data sets: a mass spectrometry data set regarding Staphylococcus aureus for predicting methicillin resistance (3338 cases; 268 features) and a urinalysis data set for predicting Trichomonas vaginalis infection (839,164 cases; 9 features). We compared the performance of the nine inference algorithms in terms of accuracy, area under the receiver operating characteristic curve (AUROC), time consumption, and power consumption. The time and power consumption levels were determined using performance counter data from Intel Power Gadget 3.5.

Results

The experimental results indicated that the RF and XGB algorithms achieved the two highest AUROC values for both data sets (84.7% and 83.9%, respectively, for the mass spectrometry data set; 91.1% and 91.4%, respectively, for the urinalysis data set). The XGB and LR algorithms exhibited the shortest inference time for both data sets (0.47 milliseconds for both in the mass spectrometry data set; 0.39 and 0.47 milliseconds, respectively, for the urinalysis data set). Compared with the RF algorithm, the XGB and LR algorithms exhibited a 45% and 53%-60% reduction in inference time for the mass spectrometry and urinalysis data sets, respectively. In terms of energy efficiency, the XGB algorithm exhibited the lowest power consumption for the mass spectrometry data set (9.42 Watts) and the LR algorithm exhibited the lowest power consumption for the urinalysis data set (9.98 Watts). Compared with a five-hidden-layer NN, the XGB and LR algorithms achieved 16%-24% and 9%-13% lower power consumption levels for the mass spectrometry and urinalysis data sets, respectively. In all experiments, the XGB algorithm exhibited the best performance in terms of accuracy, run time, and energy efficiency.

Conclusions

The XGB algorithm achieved balanced performance levels in terms of AUROC, run time, and energy efficiency for the two clinical laboratory data sets. Considering the energy constraints in real-world scenarios, the XGB algorithm is ideal for medical AI applications.

Improvement of Background Solution for Optically Induced Dielectrophoresis-Based Cell Manipulation in a Microfluidic System

Optically induced dielectrophoresis (ODEP) is effective for cell manipulation. However, its utilization has been limited by the requirement of solution with low conductivity. This issue has been ignored in ODEP-relevant studies. To address this issue, this study aims to investigate to what extent the cell viability and performance of ODEP-based cell manipulation are affected by low conductivity conditions. Additionally, this study aims to modify sucrose solutions to reduce the impacts caused by low-conductivity solutions. Results revealed the use of sucrose solution in ODEP operation could significantly reduce the viability of the manipulated cells by 9.1 and 38.5% after 2- and 4-h incubation, respectively. Prolonged operation time (e.g., 4 h) in sucrose solution could lead to significantly inferior performance of cell manipulation, including 47.2% reduction of ODEP manipulation velocity and 44.4% loss of the cells manipulatable by ODEP. The key finding of this study is that the use of bovine serum albumin (BSA)-supplemented sucrose solution (conductivity: 25–50 μS cm⁻¹) might significantly increase the cell viability by 10.9–14.8% compared with that in sucrose solution after 4 h incubation. Moreover, the ODEP manipulation velocity of cells in the BSA-supplemented sucrose solution (conductivity: 25 μS cm⁻¹) was comparable to that in sucrose solution during 4-h incubation. More importantly, compared with sucrose solution, the use of BSA-supplemented sucrose solution (conductivity: 25–50 μS cm⁻¹) contributed high percentage (80.4–93.5%) of the cells manipulatable by ODEP during 4-h incubation. Overall, this study has provided some fundamental information relevant to the improvement of background solutions for ODEP-based cell manipulation.

Definitive concurrent chemoradiotherapy with paclitaxel plus carboplatin is superior to cisplatin plus 5-fluorouracil in patients with inoperable esophageal squamous cell carcinoma using retrospective, real-world evidence

Background

The optimal definitive chemotherapy regimen during concurrent chemoradiotherapy (CRT) for patients with advanced esophageal squamous cell carcinoma (ESCC) remains unclear because of conflicting evidence. This study aimed to compare the effectiveness of taxane‐based chemotherapy with that of conventional cisplatin plus 5‐fluorouracil (PF) as the chemotherapy regimen in definitive CRT for ESCC.

Patients and Methods

This retrospective study included patients with ESCC who received paclitaxel plus carboplatin (PC) or PF during definitive CRT between May 2012 and February 2015 in a medical center in Taiwan. Survival outcomes were compared after adjustment for risk factors.

Results

Overall, 229 patients were evaluated. Patients in the PC group had an objective response rate of 71.1% compared with the 51.4% of the PF group (p = 0.016). The PC group showed a significantly longer progression‐free survival (PFS, p = 0.002) and overall survival (OS, p = 0.019) than the PF group. Salvage surgery also helped prolong both the PFS and OS (p < 0001). Sex (male vs. female, HR, 1.831; 95% CI, 1.016–3.303), clinical stage (HR, 1.282; 95% CI, 1.069–1.537), accumulative radiation dose (≥41.4 Gy vs. <41.4 Gy; HR, 0.640; 95% CI, 0.413–0.993), salvage surgery (yes vs. no, HR: 0.412, 95% CI: 0.298–0.570), and regimen (PF vs. PC; HR, 1.514; 95% CI, 1.109–2.067) were independent prognostic factors for cancer mortality.

Conclusion

Compared with the PF regimen, the PC regimen for definitive CRT yielded significantly increased response rates and longer survival times; therefore, the PC regimen may be preferable for chemotherapy for definitive CRT in patients with advanced ESCC.

Investigate clinical characteristics and genetic mutations of CPVT patients in Taiwan and risk stratification

Funding Acknowledgements

Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Ministry of Science and Technology

Background

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare and lethal arrhythmia in children and young adults. RYR2 mutation accounts for 60% of CPVT patients. While many articles about CPVT are published in the Caucasian population, only a few studies are based on Asian ethnicity. A CPVT scorecard proposed using Caucasian patients is proven effective in reducing the burden of variants of uncertain significance (VUS) of RYR2 mutations is not yet tested in the Asian population.

Purpose

Identify mutations among Taiwanese CPVT patients and compare genetic and clinical results with other ethnicities. We also tested the efficacy of the CPVT scorecard in Taiwanese CPVT patients.

Methods

40 clinically diagnosed CPVT patients and their family members were consecutively enrolled from multi-centers. We compared clinical characteristics and genetic results with other ethnicities, and applied the Caucasian CPVT scorecard to test whether it is applicable in Taiwanese CPVT patients.

Results

This is the first nationwide CPVT cohort in Taiwan. Among the 29 patients with CPVT-related gene mutation, 12 RYR2 variants was identified in our cohort with 5 of them unreported in previous studies. The RYR2 yield rate was 55%, similar to other ethnicities. Exercise-induced symptoms including syncope and cardiac arrest were more severe in Taiwanese CPVT cohort, compared to Japanese and Caucasian cohorts. The CPVT scorecard also successfully reduced the VUS rate for the Taiwanese cohort.

Conclusions

Our study demonstrated genetic difference in CPVT patients across ethnicities, suggesting the importance of genetic testing in Taiwan. The CPVT scorecard is applicable to Taiwanese CPVT patients and is a helpful tool in interpreting genetic test results in clinical practice. Clinical characteristics of the cohort Gender (male, %) 15 (52%) Mean age of onset (years) 18 ± 15 Exercise-related syncope or cardiac arrest (n, %) 23 (79%) Exercise-related cardiac arrest (n, %) 14 (48%) Family history of unexplained sudden cardiac death (n, %) 5 (17%) Heart rate (bpm) 73 ± 16 Exercise stress test or Holter positive (n, %) 14 (48%) Ventricular arrhythmia (n, %) 23 (79%) Beta-blockers only (n, %) 10 (35%) Intracardiac defibrillator implantation (n, %) 15 (52%) CPVT score 6 ± 3

Development of a two-step nucleic acid amplification test for accurate diagnosis of the Mycobacterium tuberculosis complex

The Mycobacterium tuberculosis complex (MTBC) remains one of the top 10 leading causes of death globally. The early diagnosis of MTBC can reduce mortality and mitigate disease transmission. However, current nucleic acid amplification diagnostic test methods are generally time-consuming and show suboptimal diagnostic performance, especially in extrapulmonary MTBC samples or acid-fast stain (AFS)-negative cases. Thus, development of an accurate assay for the diagnosis of MTBC is necessary, particularly under the above mentioned conditions. In this study, a single-tube nested real-time PCR assay (N-RTP) was developed and compared with a newly in-house-developed high-sensitivity real-time PCR assay (HS-RTP) using 134 clinical specimens (including 73 pulmonary and 61 extrapulmonary specimens). The amplification efficiency of HS-RTP and N-RTP was 99.8% and 100.7%, respectively. The sensitivity and specificity of HS-RTP and N-RTP for the diagnosis of MTBC in these specimens were 97.5% (77/79) versus 94.9% (75/79) and 80.0% (44/55) versus 89.1% (49/55), respectively. The sensitivity and specificity of HS-RTP and N-RTP for the diagnosis of MTBC in pulmonary specimens were 96.3% (52/54) versus 96.3% (52/54) and 73.7.0% (14/19) versus 89.5% (17/19), respectively; in extrapulmonary specimens, the sensitivity and specificity of HS-RTP and N-RTP were 100% (25/25) versus 92% (23/25) and 83.3% (30/36) versus 88.9% (32/36), respectively. Among the AFS-negative cases, the sensitivity and specificity of HS-RTP and N-RTP were 97.0% (32/33) versus 90.9% (30/33) and 88.0% (44/50) versus 92.0% (46/50), respectively. Overall, the sensitivity of HS-RTP was higher than that of N-RTP, and the performance was not compromised in extrapulmonary specimens and under AFS-negative conditions. In contrast, the specificity of the N-RTP assay was higher than that of the HS-RTP assay in all types of specimens. In conclusion, the HS-RTP assay would be useful for screening patients suspected of exhibiting an MTBC infection due to its higher sensitivity, while the N-RTP assay could be used for confirmation because of its higher specificity. Our results provide a two-step method (screen to confirm) that simultaneously achieves high sensitivity and specificity in the diagnosis of MTBC.

An integrated actuating and sensing system for light-addressable potentiometric sensor (LAPS) and light-actuated AC electroosmosis (LACE) operation

To develop a lab on a chip (LOC) integrated with both sensor and actuator functions, a novel two-in-one system based on optical-driven manipulation and sensing in a microfluidics setup based on a hydrogenated amorphous silicon (a-Si:H) layer on an indium tin oxide/glass is first realized. A high-intensity discharge xenon lamp functioned as the light source, a chopper functioned as the modulated illumination for a certain frequency, and a self-designed optical path projected on the digital micromirror device controlled by the digital light processing module was established as the illumination input signal with the ability of dynamic movement of projected patterns. For light-addressable potentiometric sensor (LAPS) operation, alternating current (AC)-modulated illumination with a frequency of 800 Hz can be generated by the rotation speed of the chopper for photocurrent vs bias voltage characterization. The pH sensitivity, drift coefficient, and hysteresis width of the Si₃N₄ LAPS are 52.8 mV/pH, -3.2 mV/h, and 10.5 mV, respectively, which are comparable to the results from the conventional setup. With an identical two-in-one system, direct current illumination without chopper rotation and an AC bias voltage can be provided to an a-Si:H chip with a manipulation speed of 20 μm/s for magnetic beads with a diameter of 1 μm. The collection of magnetic beads by this light-actuated AC electroosmosis (LACE) operation at a frequency of 10 kHz can be easily realized. A fully customized design of an illumination path with less decay can be suggested to obtain a high efficiency of manipulation and a high signal-to-noise ratio of sensing. With this proposed setup, a potential LOC system based on LACE and LAPS is verified with the integration of a sensor and an actuator in a microfluidics setup for future point-of-care testing applications.

Novel Toilet Paper-Based Point-Of-Care Test for the Rapid Detection of Fecal Occult Blood: Instrument Validation Study

BACKGROUND

Colorectal cancer screening by fecal occult blood testing has been an important public health test and shown to reduce colorectal cancer-related mortality. However, the low participation rate in colorectal cancer screening by the general public remains a problematic public health issue. This fact could be attributed to the complex and unpleasant operation of the screening tool.

OBJECTIVE

This study aimed to validate a novel toilet paper-based point-of-care test (ie, JustWipe) as a public health instrument to detect fecal occult blood and provide detailed results from the evaluation of the analytic characteristics in the clinical validation.

METHODS

The mechanism of fecal specimen collection by the toilet-paper device was verified with repeatability and reproducibility tests. We also evaluated the analytical characteristics of the test reagents. For clinical validation, we conducted comparisons between JustWipe and other fecal occult blood tests. The first comparison was between JustWipe and typical fecal occult blood testing in a central laboratory setting with 70 fecal specimens from the hospital. For the second comparison, a total of 58 volunteers were recruited, and JustWipe was compared with the commercially available Hemoccult SENSA in a point-of-care setting.

RESULTS

Adequate amounts of fecal specimens were collected using the toilet-paper device with small day-to-day and person-to-person variations. The limit of detection of the test reagent was evaluated to be 3.75 µg of hemoglobin per milliliter of reagent. Moreover, the test reagent also showed high repeatability (100%) on different days and high reproducibility (>96%) among different users. The overall agreement between JustWipe and a typical fecal occult blood test in a central laboratory setting was 82.9%. In the setting of point-of-care tests, the overall agreement between JustWipe and Hemoccult SENSA was 89.7%. Moreover, the usability questionnaire showed that the novel test tool had high scores in operation friendliness (87.3/100), ease of reading results (97.4/100), and information usefulness (96.1/100).

CONCLUSIONS

We developed and validated a toilet paper-based fecal occult blood test for use as a point-of-care test for the rapid (in 60 seconds) and easy testing of fecal occult blood. These favorable characteristics render it a promising tool for colorectal cancer screening as a public health instrument.

The Combination of Immunomagnetic Bead-Based Cell Isolation and Optically Induced Dielectrophoresis (ODEP)-Based Microfluidic Device for the Negative Selection-Based Isolation of Circulating Tumor Cells (CTCs)

Negative selection-based circulating tumor cell (CTC) isolation is able to harvest viable, label-free, and clinically meaningful CTCs from the cancer patients' blood. Nevertheless, its main shortcoming is its inability to isolate high-purity CTCs, restricting subsequent CTC-related analysis. To address this issue, this study proposed a two-step optically-induced dielectrophoresis (ODEP) cell manipulation to process the cell sample harvested by negative selection-/immunomagnetic microbeads-based CTC isolation. The working mechanism is that the ODEP force acting on the cells with and without magnetic microbeads binding is different. Accordingly, the use of ODEP cell manipulation in a microfluidic system was designed to first separate and then isolate the cancer cells from other magnetic microbead-bound cells. Immunofluorescent microscopic observation and ODEP cell manipulation were then performed to refine the purity of the cancer cells. In this study, the optimum operating conditions for effective cell isolation were determined experimentally. The results revealed that the presented method was able to further refine the purity of cancer cell in the sample obtained after negative selection-based CTC isolation with high cell purity (81.6~86.1%). Overall, this study proposed the combination of immunomagnetic bead-based cell isolation and ODEP cell manipulation for the negative selection-based isolation of CTCs.

Review of emerging biomarkers in head and neck squamous cell carcinoma in the era of immunotherapy and targeted therapy

BACKGROUND

Biomarkers in head and neck squamous cell carcinoma (HNSCC) emerge rapidly in recent years, especially for new targeted therapies and immunotherapies.

METHODS

Recent, relevant peer-reviewed evidence were critically reviewed and summarized.

RESULTS

This review article briefly introduces essential biomarker concepts, including purposes and classifications (predictive, prognostic, and diagnostic markers), and the phases of biomarker development. We summarize current biomarkers in order of clinical utility; p16 and human papillomavirus status remain the most important and validated biomarkers in HNSCC. The rationale for biomarker study design continues to evolve with technological advances, especially whole-exome or whole-genomic sequencing. Noninvasive body fluid and liquid biopsy biomarkers appear to hold strong potential for development as tools for early cancer detection, cancer diagnosis, monitoring of disease recurrence, and outcome prediction. In light of discrepancies among different technologies, standardized approaches are needed.

CONCLUSION

Biomarkers from cancer tissue or blood in HNSCC could direct new anticancer therapies.

The Effect of Optically Induced Dielectrophoresis (ODEP)-Based Cell Manipulation in a Microfluidic System on the Properties of Biological Cells

Cell manipulation using optically induced dielectrophoresis (ODEP) in microfluidic systems has attracted the interest of scientists due to its simplicity. Although this technique has been successfully demonstrated for various applications, one fundamental issue has to be addressed—Whether, the ODEP field affects the native properties of cells. To address this issue, we explored the effect of ODEP electrical conditions on cellular properties. Within the experimental conditions tested, the ODEP-based cell manipulation with the largest velocity occurred at 10 Vpp and 1 MHz, for the two cancer cell types explored. Under this operating condition, however, the cell viability of cancer cells was significantly affected (e.g., 70.5 ± 10.0% and 50.6 ± 9.2% reduction for the PC-3 and SK-BR-3 cancer cells, respectively). Conversely, the exposure of cancer cells to the ODEP electrical conditions of 7–10 Vpp and 3–5 MHz did not significantly alter the cell viability, cell metabolic activity, and the EpCAM, VIM, and ABCC1 gene expression of cancer cells. Overall, this study fundamentally investigated the effect of ODEP electrical conditions on the cellular properties of cancer cells. The information obtained is crucially important for the utilization of ODEP-based cell manipulation in a microscale system for various applications.

Improving Multi-Tumor Biomarker Health Check-up Tests with Machine Learning Algorithms

BACKGROUND

Tumor markers are used to screen tens of millions of individuals worldwide at annual health check-ups, especially in East Asia. Machine learning (ML)-based algorithms that improve the diagnostic accuracy and clinical utility of these tests can have substantial impact leading to the early diagnosis of cancer.

METHODS

ML-based algorithms, including a cancer screening algorithm and a secondary organ of origin algorithm, were developed and validated using a large real world dataset (RWD) from asymptomatic individuals undergoing routine cancer screening at a Taiwanese medical center between May 2001 and April 2015. External validation was performed using data from the same period from a separate medical center. The data set included tumor marker values, age, and gender from 27,938 individuals, including 342 subsequently confirmed cancer cases.

RESULTS

Separate gender-specific cancer screening algorithms were developed. For men, a logistic regression-based algorithm outperformed single-marker and other ML-based algorithms, with a mean area under the receiver operating characteristic curve (AUROC) of 0.7654 in internal and 0.8736 in external cross validation. For women, a random forest-based algorithm attained a mean AUROC of 0.6665 in internal and 0.6938 in external cross validation. The median time to cancer diagnosis (TTD) in men was 451.5, 204.5, and 28 days for the mild, moderate, and high-risk groups, respectively; for women, the median TTD was 229, 132, and 125 days for the mild, moderate, and high-risk groups. A second algorithm was developed to predict the most likely affected organ systems for at-risk individuals. The algorithm yielded 0.8120 sensitivity and 0.6490 specificity for men, and 0.8170 sensitivity and 0.6750 specificity for women.

CONCLUSIONS

ML-derived algorithms, trained and validated by using a RWD, can significantly improve tumor marker-based screening for multiple types of early stage cancers, suggest the tissue of origin, and provide guidance for patient follow-up.

Probing circuit of Papez with stimulation of anterior nucleus of the thalamus and hippocampal evoked potentials

PURPOSE

Despite documented clinical effectiveness, deep brain stimulation (DBS) therapy for drug-resistant epilepsy rarely yields long-term seizure free outcomes.

METHODS

This pilot study in five patients investigated circuit of Papez evoked potentials (EPs) using hippocampal sensing during anterior nucleus of the thalamus (ANT) electrical stimulation. We hypothesize that hippocampal EP is a potential biomarker that could be useful for ANT electrode targeting and improving seizure reduction. We obtained bilateral circuit of Papez EPs in five patients with bilateral temporal lobe epilepsy (TLE). The circuit of Papez EPs were measured and assessed by signal amplitude. Volumetric analysis of relevant mesial temporal structures and ANT stimulation analysis was performed on immediate post-implantation images.

RESULTS

The patient with the most favorable seizure outcome, which meant long-term seizure reduction greater than 50 % compared to baseline, had strong bilateral EPs and normal hippocampal structure. Conversely, those without clinical benefit with ANT DBS had absent or weak bilateral EPs as well as MRI findings consistent with mesial temporal sclerosis (MTS).

CONCLUSION

The data support the hypothesis that hippocampal EPs with ANT stimulation may be used to as a surrogate marker to probe circuit of Papez and predict ANT DBS efficacy.

[The significance of eosinophils in the correlation of upper and lower airway inflammation in patients with chronic rhinitis]

Objective: To explore the predictor of lower airway inflammation among the index of nasal inflammation by investigating the expression and association of eosinophils (EOS) in the upper-lower airways and blood of patients with chronic rhinitis. Methods: A total of 162 patients with allergic rhinitis (AR), 117 patients with non-allergic rhinitis (NAR) and 104 controls were enrolled from June 2010 to December 2013 from General Hospital of Eastern Theater Command, People's Liberation Army. All subjects were required detailed medical history collection and nasal resistance measurement. Skin prick test (SPT), blood total immunoglobin E (tIgE) and blood EOS, nasal lavage and induced sputum EOS, nasal provocation and bronchial provocation test (NPT, BPT), nasal and forced exhaled nitric oxide (NNO, FeNO) were performed in all patients. One-way analysis of variance was used for comparison between groups. LSD t test or Mann-Whitney U test was used for comparison between the two groups. Pearson or Spearman related parameter test was used for correlation analysis. Results: The nasal lavage EOS, NNO, induced sputum EOS, FeNO, blood EOS and tIgE were higher in the AR group than that in the NAR group (3.70[1.20, 14.23]/200 HP vs 1.40[0.20, 3.40]/200 HP, 673.50[466.80, 936.00] ppb vs 455.80[248.10, 705.60] ppb, 2.97[0.00, 10.63]% vs 1.00[0.23, 2.00]%, (49.28±26.37)ppb vs (34.07±19.11)ppb, 4.00[2.00, 7.00]% vs 2.00[1.00, 5.00]%, 208.01[61.70, 387.50] IU/ml vs 43.30[19.00, 122.00] IU/ml, F or χ(2) value was 11.442, 19.440, 70.727, 69.449, 47.453, 46.525, respectively, all P<0.05). But there was no significant difference in nasal resistance, NPT and BPT between the two groups. Nasal lavage EOS in AR group and NAR group was correlated with induced sputum EOS, FeNO, tIgE and blood EOS (r value of AR group was 0.448, 0.202, 0.159, 0.321, r value of NAR group was 0.442, 0.268, 0.268, 0.334, respectively, all P<0.05), but not with BPT. After adjustment for gender, age, height and weight, nasal EOS was positively correlated with sputum EOS. Multiple linear regression analysis showed that nasal EOS, blood EOS and SPT were factors affecting sputum EOS levels. The optimal threshold for nasal EOS to determine induced sputum EOS was 3.30/200 HP by (receiver operating characteristic,ROC) analysis. Conclusion: The nasal EOS is correlated with multiple lower airway and systemic inflammatory markers, and is a risk factor for the induced sputum EOS, which can be used as an inflammation biomarker to predict the lower air inflammation.

The Prognostic Roles of Pretreatment Circulating Tumor Cells, Circulating Cancer Stem-Like Cells, and Programmed Cell Death-1 Expression on Peripheral Lymphocytes in Patients with Initially Unresectable, Recurrent or Metastatic Head and Neck Cancer: An Exploratory Study of Three Biomarkers in One-time Blood Drawing

Circulating tumor cells (CTCs) and immune status are strongly related to cancer prognosis, although few studies have examined both factors. This prospective observational study (ClinicalTrials.gov: NCT02420600) evaluated whether CTCs, circulating cancer stem-like cells (cCSCs), and peripheral lymphocytes with/without Programmed cell death protein 1 (PD-1) expression were associated with prognosis among patients receiving palliative chemotherapy for initially unresectable, recurrent/metastatic head and neck squamous cell carcinoma (rmHNSCC). Thirty-four patients were enrolled between January 2015 and June 2016. Overall survival (OS) was associated with a higher CTC number (hazard ratio [HR]: 1.01, p = 0.0004) and cCSC ratio (HR: 29.903, p < 0.0001). Progression-free survival (PFS) was also associated with CTC number (HR: 1.013, p = 0.002) and cCSC ratio (HR: 10.92, p = 0.003). A CD8⁺ proportion of ≥ 17% was associated with improved OS (HR: 0.242, p = 0.004). A CD4: CD8 ratio of >1.2 was associated with poorer trend of PFS (HR: 2.12, p = 0.064). PD-1 expression was not associated with survival outcomes. Baseline CTCs, cCSC ratio, and CD8⁺ ratio may predict prognosis in rmHNSCC.

The change in circulating tumor cells before and during concurrent chemoradiotherapy is associated with survival in patients with locally advanced head and neck cancer

BACKGROUND

This study aimed to evaluate the role of baseline circulating tumor cells (CTCs) before and during concurrent chemoradiotherapy and attempted to determine the impacts of CTCs on the outcomes in patients with head and neck squamous cell carcinoma.

METHODS

CTCs were detected using a negative selection strategy and flow cytometry protocol.

RESULTS

We observed a significant correlation between baseline CTCs and staging (P = 0.001). The CTC counts were significantly reduced within 2-4 weeks in 47 concurrent chemoradiotherapy responders (P < 0.001). Change of CTC counts correlates with progression-free survival (PFS, P = 0.01) and overall survival (OS, P = 0.01). CTC decline status was an independent prognostic factor in PFS (P = 0.03) and OS (P = 0.05) in multivariate analyses.

CONCLUSION

In chemoradiotherapy responders, CTCs are significantly reduced. CTC decline within the first month indicates a longer PFS and OS, suggesting that the dynamics of CTCs could be more important than CTC number alone.

Targeting analysis of a novel parietal approach for deep brain stimulation of the anterior nucleus of the thalamus for epilepsy

PURPOSE

Deep brain stimulation (DBS) of the anterior nucleus of the thalamus (ANT) is a promising treatment for refractory epilepsy; however, it remains challenging to successfully target the ANT. The results of Medtronic Registry for Epilepsy (MORE) supported a frontal transventricular(TV) compared to frontal extraventricular (EV) lead trajectory for ANT DBS may have better coverage of the ANT. Here we report the safety and targeting efficacy of a novel, posterior parietal extraventricular (PEV) approach to the ANT.

METHODS

We conducted a retrospective analysis of ten patients who underwent bilateral ANT DBS (20 total trajectories) for medically-refractory epilepsy. Similar targeting methodology as the MORE trial was used, and the DBS Intrinsic Template Atlas (DISTAL) was utilized for ANT localization and contact position relative to ANT. Clinical data were assessed for DBS targeting efficacy and surgical complications.

RESULTS

The demonstrated PEV trajectory showed a successful ANT targeting rate of 90% bilaterally. Two or more contacts within ANT were presented in 75% of all leads. Mean contact number in ANT was 2.2+ 1.2. There were no intracranial hemorrhages, cerebrospinal fluid leakage, or permanent neurologic deficits.

CONCLUSION

In this small series, the novel PEV for ANT DBS is feasible with good targeting accuracy and potential safety advantages. The high accuracy of the PEV trajectory suggests that it is a reasonable alternative trajectory for ANT DBS. Larger studies will be needed to assess this trajectory on clinical outcome of DBS treatment to epilepsy.

Development of a high sensitivity TaqMan-based PCR assay for the specific detection of Mycobacterium tuberculosis complex in both pulmonary and extrapulmonary specimens

Tuberculosis (TB) causes a heavy health burden worldwide, especially in developing countries. The need for the rapid and accurate diagnosis of TB has not been satisfied, especially for extra-pulmonary specimens or specimens with acid fast stain (AFS)-negative condition. Development and validation of a novel, sensitive and specific assay for diagnosing TB is essential. We developed IS4 primer/probe based on insertion sequence 6110 (IS6110). A qPCR assay was designed for detecting a specific region in IS6110 by BLAST. The IS4 primer/probe concentration, qPCR efficiency and various of PCR additives were evaluated and optimized. Thirty-four species of commonly isolated microorganisms were used for evaluating the analytical specificity. Moreover, 130 clinical specimens were collected for evaluating the performance versus Cobas TaqMan MTB (CTM) assay kit and culture. The amplification efficiencies of IS4 were 99.61% and 102.61% without and with internal control DNA (Bacteriophage Lambda), respectively. Dimethyl sulfoxide outperformed glycerol or BSA for eliciting the most effective amplification and the lowest limit of detection. In evaluating the clinical performance, various specimen types were collected. IS4 demonstrated a high degree of agreement (kappa = 0.71) with CTM. The clinical sensitivity and specificity of IS4 and CTM were 92.11% (35/38), 82.61% (76/92), 84.21% (32/38) and 95.65% (88/92), respectively. The clinical sensitivity and specificity of IS4 were similar for both pulmonary [92.00% (23/25) and 76.92% (30/39), respectively] and extrapulmonary [92.31% (12/13) and 86.79% (46/53), respectively] specimens. Among AFS-negative cases, the clinical sensitivity and specificity remained 90.48% (19/21) and 83.91% (73/87), respectively, with culture as the gold standard. We concluded that IS4, a new primer/probe pair for TaqMan based qPCR assay, was developed, optimized, and validated for the sensitive and specific detection of TB among various specimen types. The performance was not compromised under AFS-negative conditions.

[The standardization of inflammation detecting methods in upper and lower airways]

Objective:To investigate the standardization of inflammation detecting methods in upper and lower airways. Method:After a five year cooperation with Guangzhou Institute of Respiratory Diseases on inflammatory diseases of airways, we have found a series of evaluation methodology and normative values in upper and lower airways (NO), airway hyper reactivity and cytology (Eos). Result:The normative range of nasal and pulmonary NO is 400-900 ppb and 5-25 ppb respectively. The nasal resistance increased ≥100% and FEV1 fell ≥20% when compared with their respective baselines both illustrating a positive result. The positive value of nasal and pulmonary Eos are ≥2.00/HP and ≥2.5% respectively. Conclusion:The standardization of evaluation methods for upper and lower airway inflammation provides the methodology and research basis for follow-up studies of upper and lower airways.

An Optically Induced Dielectrophoresis (ODEP)-Based Microfluidic System for the Isolation of High-Purity CD45neg/EpCAMneg Cells from the Blood Samples of Cancer Patients-Demonstration and Initial Exploration of the Clinical Significance of These Cells

Circulating tumour cells (CTCs) in blood circulation play an important role in cancer metastasis. CTCs are generally defined as the cells in circulating blood expressing the surface antigen EpCAM (epithelial cell adhesion molecule). Nevertheless, CTCs with a highly metastatic nature might undergo an epithelial-to-mesenchymal transition (EMT), after which their EpCAM expression is downregulated. In current CTC-related studies, however, these clinically important CTCs with high relevance to cancer metastasis could be missed due to the use of the conventional CTC isolation methodologies. To precisely explore the clinical significance of these cells (i.e., CD45^neg/EpCAM^neg cells), the high-purity isolation of these cells from blood samples is required. To achieve this isolation, the integration of fluorescence microscopic imaging and optically induced dielectrophoresis (ODEP)-based cell manipulation in a microfluidic system was proposed. In this study, an ODEP microfluidic system was developed. The optimal ODEP operating conditions and the performance of live CD45^neg/EpCAM^neg cell isolation were evaluated. The results demonstrated that the proposed system was capable of isolating live CD45^neg/EpCAM^neg cells with a purity as high as 100%, which is greater than the purity attainable using the existing techniques for similar tasks. As a demonstration case, the cancer-related gene expression of CD45^neg/EpCAM^neg cells isolated from the blood samples of healthy donors and cancer patients was successfully compared. The initial results indicate that the CD45^neg/EpCAM^neg nucleated cell population in the blood samples of cancer patients might contain cancer-related cells, particularly EMT-transformed CTCs, as suggested by the high detection rate of vimentin gene expression. Overall, this study presents an ODEP microfluidic system capable of simply and effectively isolating a specific, rare cell species from a cell mixture.

Delayed diagnosis of atrial fibrillation after first-ever stroke increases recurrent stroke risk: a 5-year nationwide follow-up study

BACKGROUND

Delayed detection of atrial fibrillation (AF) is common in patients with stroke. However, it is not well known whether delayed identification of AF in patients with stroke affects the prognosis of patients.

AIMS

To evaluate the association between the timing of AF diagnosis after stroke and clinical outcomes.

METHODS

We identified a cohort of all patients admitted with a primary diagnosis of first-ever ischaemic stroke, which was categorised into three groups, namely, non-AF, AF presenting with stroke and delayed AF diagnosis groups. The study patients were individually followed for 5 years to evaluate the occurrence of recurrent stroke and death.

RESULTS

In total, 17 399 patients were hospitalised with first-ever ischemic stroke, of whom 16 261 constituted the non-AF group, 907 the AF presenting with stroke group and 231 the delayed AF diagnosis group. During the 5-year follow up, 2773 (17.1%), 175 (19.3%) and 68 (29.4%) patients in the non-AF, AF presenting with stroke and delayed AF diagnosis groups, respectively, were hospitalised for recurrent stroke. The delayed AF diagnosis group exhibited a 1.57-times higher risk of recurrent stroke than the AF presenting with stroke group, after adjustment for the CHA2DS2-VASc scores (adjusted hazard ratio (HR): 1.57; 95% confidence interval (CI) = 1.19-2.08; P = 0.002). In addition, delayed diagnosis of AF significantly increased the risk of recurrent stroke in men, but not in women, after adjustment for the CHA2DS2-VASc scores.

CONCLUSION

Delayed diagnosis of AF after stroke increased the risk of recurrent stroke, particularly in men.

Membrane capacitance of thousands of single white blood cells

As label-free biomarkers, the electrical properties of single cells are widely used for cell type classification and cellular status evaluation. However, as intrinsic cellular electrical markers, previously reported membrane capacitances (e.g. specific membrane capacitance C_spec and total membrane capacitance C_mem) of white blood cells were derived from tens of single cells, lacking statistical significance due to low cell numbers. In this study, white blood cells were first separated into granulocytes and lymphocytes by density gradient centrifugation and were then aspirated through a microfluidic constriction channel to characterize both C_spec and C_mem Thousands of granulocytes (n_cell = 3327) and lymphocytes (n_cell = 3302) from 10 healthy blood donors were characterized, resulting in C_spec values of 1.95 ± 0.22 µF cm^-2 versus 2.39 ± 0.39 µF cm^-2 and C_mem values of 6.81 ± 1.09 pF versus 4.63 ± 0.57 pF. Statistically significant differences between granulocytes and lymphocytes were located for both C_spec and C_mem In addition, neural network-based pattern recognition was used to classify white blood cells, producing successful classification rates of 78.1% for C_spec and 91.3% for C_mem, respectively. These results indicate that as intrinsic bioelectrical markers, membrane capacitances may contribute to the classification of white blood cells.

[The role of NF-κB signaling pathway in laryngeal leukoplakia recurrent with laryngeal reflux]

Objective: To study the mechanism of vocal mucosal barrier damage mediated by NF-κB and NF-κB-regulated signaling pathway via probing the expression of inflammatory factors and essential proteins for node of NF-κB signaling pathway. Methods: The patients suffering from vocal leukoplakia accompanied with larygopharyngeal reflux(LPR) were treated with oral administration of proton pump inhibitor(PPI). Mucosal specimens of vocal cord were collected from all patients before PPI treatment. And the mucosal specimens of vocal cord were collected from the patients with suspected recurrence at 8 weeks after PPI treatment. HE staining was used to observe the histopathological changes of the mucosa. ELISA was utilized to detect the levels of inflammatory factors including tumor necrosis factor(TNF)-α, interleukin(IL)-1 and IL-6. Western blot was used to detect the expression of p-p65, p-IKK and p-IκB. Immunofluorescence method was adopted to detect the entrance of p65 to cell nucleus.Data was analyzed by SPSS 23.0 software. Results: In PPI untreated group, the expressions of IL-1β, TNF-α and IL-6 in the specimens of 8 weeks after operation were not different significantly from those obtained during operation.But in the PPI-treated group, the expressions were down-regulated.The expression of p-p65 in the middle and high grade heterogenous hyperplasia group was higher than that of low level heterogenous hyperplasia group.The difference of p65 and p-p65 expression between 8 weeks after surgery and surgery in PPI-untreated group was statistically insignificant (P>0.05). The difference of p65 expression between PPI-treated group and PPI pre-treatment group was statistically insignificant (P>0.05). The expression of p-p65 in the PPI-treated group was lower than that of the PPI pre-treatment group (P<0.05). The expressions of IL-1β, TNF-α and IL-6 were positively related with that of NF-κB-p65. Immun of luorescence method revealed the entrance of p65 to cell nucleus in PPI pre-treatment group, which meant that NF-κB was activated. In the PPI-treated group, few activated p65 could be observed in the cell nucleu. Conclusion: The possible mechanism of vocal mucosal barrier damage in vocal leukoplakia accompanied with LPR maybe the vocal mucosal inflammation mediated by NF-κB and NF-κB-regulated signaling pathway activated with refluxed materials.

Mechanical property characterization of hundreds of single nuclei based on microfluidic constriction channel

As label-free biomarkers, the mechanical properties of nuclei are widely treated as promising biomechanical markers for cell type classification and cellular status evaluation. However, previously reported mechanical parameters were derived from only around 10 nuclei, lacking statistical significances due to low sample numbers. To address this issue, nuclei were first isolated from SW620 and A549 cells, respectively, using a chemical treatment method. This was followed by aspirating them through two types of microfluidic constriction channels for mechanical property characterization. In this study, hundreds of nuclei were characterized, producing passage times of 0.5 ± 1.2 s for SW620 nuclei in type I constriction channel (n = 153), 0.045 ± 0.047 s for SW620 nuclei in type II constriction channel (n = 215) and 0.50 ± 0.86 s for A549 nuclei in type II constriction channel. In addition, neural network based pattern recognition was used to classify the nuclei isolated from SW620 and A549 cells, producing successful classification rates of 87.2% for diameters of nuclei, 85.5% for passage times of nuclei and 89.3% for both passage times and diameters of nuclei. These results indicate that the characterization of the mechanical properties of nuclei may contribute to the classification of different tumor cells.

A Prognostic Model Based on Circulating Tumour Cells is Useful for Identifying the Poorest Survival Outcome in Patients with Metastatic Colorectal Cancer

Background: There is an urgency to develop robust prognostic biomarkers for metastatic colorectal cancer (mCRC) patients receiving chemotherapy. The current study aimed to examine the prognostic significance of circulating tumour cells (CTCs) and to develop a prognostic model incorporating CTCs in predicting the outcomes of mCRC patients treated with chemotherapy. Methods: Our study prospectively enrolled 55 mCRC patients who had undergone palliative chemotherapy between 2011 and 2014. Baseline CTCs and clinicopathological variables predictive of survival outcome were identified using univariate analysis. Negative selection-based protocol plus flow cytometry was used for CTC identification. Results: The median overall survival (OS) and progression-free survival (PFS) were 24.2 months and 8.7 months, respectively. CTCs were detected in all the patients, and the median number of CTCs was 30.8/mL (range: 5.8-431.3/mL). The median OS and PFS were 37.1 and 13.3 months, respectively, for patients with CTC number ≤30/mL, while the median OS and PFS were 14.9 months and 5.1 months, respectively, for patients with CTC number >30/mL (both P<0.001). A prognostic model using CTCs in conjunction with other independent clinical variables further stratified patients into good and poor prognostic groups. The median OS and PFS were 32.4 and 11.5 months, respectively, in the good prognostic group and 5.4 and 2.7 months, respectively, in the poor prognostic group. Conclusions: We developed a reliable CTC-based prognostic model for the prediction of clinical outcomes in mCRC patients treated with chemotherapy. This model may be used to assist clinicians in identifying those with the poorest prognosis before treatment.

Analysis on the local structures for 3d1 impurities (Ti3+ and V4+ ) in KTiPO4

Making use of the perturbation formulae for 3d¹ ions (Ti³⁺ and V⁴⁺ ) under orthorhombically compressed octahedra, the spin Hamiltonian parameters (g factors: g_x , g_y , g_z and hyperfine structure constants: A_x , A_y , A_z ) and local structures of the 3d¹ impurity centres C₁ , C₂ , and C₃ in KTiOPO₄ crystals are theoretically analyzed in a consistent way. The remarkable local distortions (i.e., the relative axial compression ratios 11.2%, 7.0%, and 5.5% along Z axis and the relative planar bond length variation ratios 15.9%, 7.0%, and 6.0%) are obtained for the [Ti2O₆ ]^9- cluster on Ti2 site and [VO₆ ]^8- clusters on Ti1 and Ti2 sites, respectively, in view of the Jahn-Teller effect. The above local orthorhombic distortion parameters in the impurity centres are found to be more significant than the host Ti1 and Ti2 sites in pure KTiOPO₄ . The sequences (C₁  > C₂  > C₃ ) of the local orthorhombic distortion parameters ρ and τ are in accordance with those of the axial and perpendicular anisotropies Δg and δg of g factors, respectively.

[Efficacy and tolerance of Memantine monotherapy and combination therapy with Reinhartdt And Sea Cucumber Capsule on agitation in moderate to severe Alzheimer disease]

Objective: To explore the efficacy and tolerance of Memantine combined Reinhartdt And Sea Cucumber Capsule (R.S.C) on treating agitation in patients with moderate-severe Alzheimer disease (AD). Methods: One hundred and fifty-eight moderate-sever AD patients from Sep.2013 to Sep.2014 in Zhejiang Provincial People's Hospital were randomly divided into two groups: group of Memantine combined R. S.C and group of single Memantine. Then Mini-Mental Sate Examination (MMSE) and Neuropsychiatric Inventory (NPI) were used to evaluate cognition symptom, behavioral and psychological symptoms of dementia (BPSD) and agitation symptom at the baseline and the end of 24 weeks.The Treatment Emergent Symptom Scale (TESS) was used to assess adverse reaction and tolerance.At last, the data was analyzed by chi-square test, t-test and covariance test. Result: At the terminal of experience, the total NPI scores and agitation factor decreased markedly in both of the two groups (P<0.05). Among the patients who had agitation symptom at the baseline, the total NPI scores and agitation factor (18±5, 3.7±2.6) in group of Memantine combined R. S.C were notably lower than those in the group of single Memantine (21±6, 5.3±2.5) (P<0.05). The incidence of adverse reaction between the two groups had no significant difference (combined treatment group was 27.7%, single treatment group was 23.2%). One patient dropped out because of skin allergy, and most adverse reactions were tolerant. Conclusions: Both two groups are effective in agitation and BPSD, and Memantine combined R. S.C is better than single treatment.R.S.C dose not aggravate adverse reaction and can be well tolerated.

Abstract 3790: Circulating tumor cells at disease recurrence in patients with head and neck cancer after curative therapy

Background: Circulating tumor cell (CTC) has been prognostic and predictive in numerous types of cancer; however, its role in early diagnosis of relapse remains unclear.

Methods: Eighty-six patients were prospectively enrolled between March 2015 and June 2016. Among these patients, 51 head and neck squamous cell carcinoma (HNSCC) patients had suspicious recurrent lesion(s), whilst 35 HNSCC patients were newly diagnosed. CTC test was performed by negative selection strategy and CD45-negative and EpCAM-positive cells were identified as CTCs. Biopsy on suspicious lesion(s) and CTC analysis were performed simultaneously. We analyzed the differences of CTC numbers among HNSCC patients with true recurrence, biopsy-negative and newly-diagnosed.

Results: Mean±standard deviation(SD) of CTC numbers in baseline at diagnosis (n=35), true recurrence (n=40) and biopsy-negative (n=11) groups were 41.98±32.02, 81.75±64.91 and 16.55±6.82 cells/mL, respectively. The difference of CTC numbers among three groups was significant (P &lt;0.001). CTCs (mean±SD) among different failure types were 110.89±84.69, 105.67±50.77, 73.31±37.82 and 59.11±54.09 in lung metastasis, second primary tumor, extrapulmonary metastasis and locoregional recurrence respectively and significantly different (P = 0.049). Also, CTC numbers between first cancer (baseline at diagnosis) and second primary tumor were different (P = 0.004).

Conclusion: CTCs numbers are significantly higher in true recurrence than the biopsy-negative group when a patient had a lesion suspected to be a recurrence. CTC test may be useful to help distinguish true recurrence in HNSCC patients after curative therapy.

Citation Format: Jason Chia-Hsun Hsieh, Ting-Hsiuan Yeh, Hung-Ming Wang, Yung-Chang Lin, Nina Ming-Jung Lin, Siou-Ru Ye, Jane Ying-Chieh Lee, Min-Hsien Wu. Circulating tumor cells at disease recurrence in patients with head and neck cancer after curative therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3790. doi:10.1158/1538-7445.AM2017-3790

The Instrumentation of a Microfluidic Analyzer Enabling the Characterization of the Specific Membrane Capacitance, Cytoplasm Conductivity, and Instantaneous Young's Modulus of Single Cells

This paper presents the instrumentation of a microfluidic analyzer enabling the characterization of single-cell biophysical properties, which includes seven key components: a microfluidic module, a pressure module, an imaging module, an impedance module, two LabVIEW platforms for instrument operation and raw data processing, respectively, and a Python code for data translation. Under the control of the LabVIEW platform for instrument operation, the pressure module flushes single cells into the microfluidic module with raw biophysical parameters sampled by the imaging and impedance modules and processed by the LabVIEW platform for raw data processing, which were further translated into intrinsic cellular biophysical parameters using the code developed in Python. Based on this system, specific membrane capacitance, cytoplasm conductivity, and instantaneous Young's modulus of three cell types were quantified as 2.76 ± 0.57 μF/cm², 1.00 ± 0.14 S/m, and 3.79 ± 1.11 kPa for A549 cells (n_cell = 202); 1.88 ± 0.31 μF/cm², 1.05 ± 0.16 S/m, and 3.74 ± 0.75 kPa for 95D cells (n_cell = 257); 2.11 ± 0.38 μF/cm², 0.87 ± 0.11 S/m, and 5.39 ± 0.89 kPa for H460 cells (n_cell = 246). As a semi-automatic instrument with a throughput of roughly 1 cell per second, this prototype instrument can be potentially used for the characterization of cellular biophysical properties.

Fabrication of two-layer dissolving polyvinylpyrrolidone microneedles with different molecular weights for in vivo insulin transdermal delivery

Fabrication of two-layer dissolving polyvinylpyrrolidone microneedles for in vivo insulin transdermal delivery.

Isolation of label-free and viable circulating tumour cells (CTCs) from blood samples of cancer patients through a two-step process: negative selection-type immunomagnetic beads and spheroid cell culture-based cell isolation

A two-step CTCs purification method to isolate viable, label-free, all possible, and purity improved CTCs.

Interleukin-1β Mediates β-Catenin-Driven Downregulation of Claudin-3 and Barrier Dysfunction in Caco2 Cells

BACKGROUND

IL-1β is a cytokine involved in mediating epithelial barrier dysfunction in the gut. It is known that IL-1β mediates activation of non-muscle myosin light chain kinase in epithelial cells, but the precise mechanism by which epithelial barrier dysfunction is induced by IL-1β is not understood.

METHODS AND RESULTS

Using a Caco2 cell model, we show that the expression of the tight junction protein, claudin-3, is transcriptionally downregulated by IL-1β treatment. In addition, after assessing protein and mRNA expression, and protein localization, we show that inhibition of nmMLCK rescues IL-1β-mediated decrease in claudin-3 expression as well as junction protein redistribution. Using chromatin immunoprecipitation assays, we also show that β-catenin targeting of the claudin-3 promoter occurs as a consequence of IL-1β-mediated epithelial barrier dysfunction, and inhibition of nmMLCK interferes with this interaction.

CONCLUSIONS

Taken together, these data represent the first line of evidence demonstrating nmMLCK regulation of claudin-3 expression in response to IL-1β-treated epithelial cells.

The integrated spintronic functionalities of an individual high-spin state spin-crossover molecule between graphene nanoribbon electrodes

The spin-polarized transport properties of a high-spin-state spin-crossover molecular junction with zigzag-edge graphene nanoribbon electrodes have been studied using density functional theory combined with the nonequilibrium Green's-function formalism. The molecular junction presents integrated spintronic functionalities such as negative differential resistance behavior, spin filter and the spin rectifying effect, associated with the giant magnetoresistance effect by tuning the external magnetic field. Furthermore, the transport properties are almost unaffected by the electrode temperature. The microscopic mechanism of these functionalities is discussed. These results represent a step toward multifunctional molecular spintronic devices on the level of the individual spin-crossover molecule.

The Structure Design of Piezoelectric Poly(vinylidene Fluoride) (PVDF) Polymer-Based Sensor Patch for the Respiration Monitoring under Dynamic Walking Conditions

This study reports a piezoelectric poly(vinylidene fluoride) (PVDF) polymer-based sensor patch for respiration detections in dynamic walking condition. The working mechanism of respiration signal generation is based on the periodical deformations on a human chest wall during the respiratory movements, which in turn mechanically stretch the piezoelectric PVDF film to generate the corresponding electrical signals. In this study, the PVDF sensing film was completely encapsulated within the sensor patch forming a mass-spring-damper mechanical system to prevent the noises generated in a dynamic condition. To verify the design of sensor patch to prevent dynamic noises, experimental investigations were carried out. Results demonstrated the respiration signals generated and the respiratory rates measured by the proposed sensor patch were in line with the same measurements based on a commercial respiratory effort transducer both in a static (e.g., sitting) or dynamic (e.g., walking) condition. As a whole, this study has developed a PVDF-based sensor patch which is capable of monitoring respirations in a dynamic walking condition with high fidelity. Other distinctive features include its small size, light weight, ease of use, low cost, and portability. All these make it a promising sensing device to monitor respirations particularly in home care units.

Development of a microfluidic-based optical sensing device for label-free detection of circulating tumor cells (CTCs) through their lactic acid metabolism

This study reports a microfluidic-based optical sensing device for label-free detection of circulating tumor cells (CTCs), a rare cell species in blood circulation. Based on the metabolic features of cancer cells, live CTCs can be quantified indirectly through their lactic acid production. Compared with the conventional schemes for CTC detection, this label-free approach could prevent the biological bias due to the heterogeneity of the surface antigens on cancer cells. In this study, a microfluidic device was proposed to generate uniform water-in-oil cell-encapsulating micro-droplets, followed by the fluorescence-based optical detection of lactic acid produced within the micro-droplets. To test its feasibility to quantify cancer cells, experiments were carried out. Results showed that the detection signals were proportional to the number of cancer cells within the micro-droplets, whereas such signals were insensitive to the existence and number of leukocytes within. To further demonstrate its feasibility for cancer cell detection, the cancer cells with known cell number in a cell suspension was detected based on the method. Results revealed that there was no significant difference between the detected number and the real number of cancer cells. As a whole, the proposed method opens up a new route to detect live CTCs in a label-free manner.

Microbioreactors for Cartilage Tissue Engineering

In tissue engineering research, cell-based assays are widely utilized to fundamentally explore cellular responses to extracellular conditions. Nevertheless, the simplified cell culture models available at present have several inherent shortcomings and limitations. To tackle the issues, a wide variety of microbioreactors for cell culture have been actively proposed, especially during the past decade. Among these, micro-scale cell culture devices based on microfluidic biochip technology have particularly attracted considerable attention. In this chapter, we not only discuss the advantageous features of using micro-scale cell culture devices for cell-based assays, but also describe their fabrication, experimental setup, and application.

A pneumatically-driven microfluidic system for size-tunable generation of uniform cell-encapsulating collagen microbeads with the ultrastructure similar to native collagen

This study reports a microfluidic system for high throughput, uniform, and size-tunable generation of cell-containing collagen microbeads. The principle is based on two pneumatically-driven mechanisms to achieve multi-channel mixture suspension transportation, and to actuate the spotting actions of micro-vibrators that continuously generate tiny collagen micro-droplets into a thin oil layer and then a sterile Pluronic® F127 surfactant solution located below. The temporarily formed collagen microdroplets are then thermally gelatinized. By regulating the feeding rate of cells/collagen suspension, and the spotting frequency of micro-vibrator, the size of the collagen microbeads can be manipulated. One of the key technical features is its capability to generate uniform collagen microbeads (coefficient of variation: 5.4-8.6 %) with sizes ranging from 73.9 to 349.3 μm in diameter. This is currently difficult to achieve using the existing methods particularly the generation of cell-encapsulating collagen microbeads with diameter less than 100 μm. Another advantageous trait is that the ultrastructure of the generated collagen microbeads is similar to that found in native collagen. In this study, moreover, the use of the proposed device for the microencapsulation of 3T3 cells in collagen microbeads has been successfully demonstrated showing that the encapsulated cells maintained high cell viability (96 ± 2 %). Furthermore, a reasonable proliferative capability of the encapsulated cells was observed during 7 days culture. As a whole, the proposed device has opened up a new route to generate cell-containing collagen microbeads, which is found particularly meaningful for biomedical applications.

Protein tyrosine kinase 6 mediates TNFα-induced endothelial barrier dysfunction

A key event in the progression of systemic inflammation resulting from severe trauma or shock involves microvascular hyperpermeability, which leads to excessive plasma fluid and proteins accumulating in extravascular space resulting in tissue edema. The precise molecular mechanism of the hyperpermeability response is not completely understood. Protein tyrosine kinase 6 (PTK6, also known as breast tumor kinase BRK) is a non-receptor tyrosine kinase related to Src-family proteins. Although it has also been shown that PTK6 participates in regulating epithelial barrier function, the role of PTK6 in endothelial barrier function has not been reported. In this study, we hypothesized that PTK6 is (1) expressed in vascular endothelial cells, and (2) contributes to vascular endothelial hyperpermeability in response to TNFα. Results showed that PTK6 was detected in mouse endothelial cells at the level of protein and mRNA. In addition, PTK6 knockdown attenuated TNFα induced decrease in endothelial barrier function as measured by electric cell-substrate impedance sensing (ECIS) and in vitro transwell albumin-flux assays. Furthermore, we showed that TNFα treatment of endothelial cells increased active PTK6 association with p120-catenin at endothelial cell-cell junctions. Further analysis using immunocytochemistry and immunoprecipitation demonstrated that PTK6 knockdown attenuated TNFα induced VE-cadherin internalization as well as promoting its association with p120-catenin. Our study demonstrates a novel role of PTK6 in mediating endothelial barrier dysfunction.

A microwave applicator for uniform irradiation by circularly polarized waves in an anechoic chamber

Microwave applicators are widely employed for materials heating in scientific research and industrial applications, such as food processing, wood drying, ceramic sintering, chemical synthesis, waste treatment, and insect control. For the majority of microwave applicators, materials are heated in the standing waves of a resonant cavity, which can be highly efficient in energy consumption, but often lacks the field uniformity and controllability required for a scientific study. Here, we report a microwave applicator for rapid heating of small samples by highly uniform irradiation. It features an anechoic chamber, a 24-GHz microwave source, and a linear-to-circular polarization converter. With a rather low energy efficiency, such an applicator functions mainly as a research tool. This paper discusses the significance of its special features and describes the structure, in situ diagnostic tools, calculated and measured field patterns, and a preliminary heating test of the overall system.

Non-invasive measurement of cell viability in 3-dimensional cell culture construct

In this work, a non-invasive measurement technique for the quantitative determination of cell viability in a three-dimensional (3D) cell culture construct is proposed. This technique is based on on-site electrical impedance measurement. A microfluidic chip with a 3D culture chamber is fabricated to demonstrate this technique. In vitro 3D cell culture has been interpreted for faithfully representation of the in vivo cellular responses in 3D cell culture construct is normally time-consuming and labor-intensive. In this study, the microfluidic chip consists of a culture chamber, in which a pair of vertical electrodes at its opposite sidewalls was embedded, and a fluidic channel for drug perfusion. Cancer cells encapsulated in agarose gel were loaded into the culture chamber to perform 3D cell culture under the perfusion of culture medium and anti-cancer drug in different concentrations (6, 12, 18, and 24 µg/ml) for 2 days. Since higher drug concentration led to more cell damage or death, the total impedance magnitude of the culture construct was shown to be reasonably proportional to the anti-cancer drug concentration. Moreover, cell proliferation can be also monitored using this technique. The proposed measurement method can determine cell viability without affecting the cellular behaviors during culture. It has a high potential to develop a fast and easy measurement compared with the conventional cellular analysis techniques.

Real-time and non-invasive impedimetric monitoring of cell proliferation and chemosensitivity in a perfusion 3D cell culture microfluidic chip

A perfusion three-dimensional (3D) cell culture microfluidic chip has been developed for real-time and non-invasive impedimetric monitoring of cell proliferation and chemosensitivity. In this study, human oral cancer cells (OEC-M1) were encapsulated in 3D agarose scaffold and cultured in a miniaturized chamber under perfusion of tested substance. This setting provides a more in vitro physiologically relevant microenvironment to better mimic the complex in vivo microenvironment. A pair of vertical electrodes was embedded at the opposite sidewalls of the culture chamber for the on-site impedance measurement. Cell density in the 3D construct was shown to be proportional to the impedance magnitude of the entire construct. Therefore, perfusion 3D cell culture was performed for up to 5 days and cell proliferation can be monitored by the impedimetric analysis. Moreover, real-time impedimetric monitoring of cell viability under the perfusion of anti-cancer drug in different concentrations was conducted and the impedance magnitude was directly correlated with the cell viability. From the confirmation of the endpoint cell viability assays, a concentration-dependent effect was shown; however, the response of cell viability during the drug treatment was able to be traced by the impedance measurement. The experimental results showed that cell proliferation and chemosensitivity in 3D cell culture format can be monitored by impedance measurement. This microfluidic chip has a high potential to develop a powerful analytical platform for cancer research.