Nonlinearity vs nonlocality with emphasis on bandwidth broadening in semiconductor-based 1d metamaterials

The physics of nonlinear optical materials is incredibly versatile, with the design of novel materials and structures offering numerous degrees of freedom. Nevertheless, weak inherent nonlinearity of conventional optical materials continues to hinder the progress of a number of important applications. In this study, we delve into the realm of broadband enhancement of nonlinearity within one-dimensional (1d) plasmonic metamaterials, exploring its intricate connection with nonlocality. Specifically, we introduce a phenomenological framework for quantifying the effective third-order nonlinear susceptibility of 1d multiphase plasmonic nanostructures, utilizing heavily doped semiconductors, and subsequently applying this approach using realistic material parameters. Both direct and inverse problems of nonlinearity enhancement have been addressed. Our findings demonstrate a remarkable capability to significantly augment the third-order nonlinear susceptibility across a defined frequency range, while concurrently gauging the impact of nonlocality on this enhancement.

Automated Detection, Segmentation, and Tracking of Brain Metastases in Repeated Courses of Stereotactic Radiosurgery Using Integrated Artificial Intelligence

PURPOSE/OBJECTIVE(S)

Salvage stereotactic radiosurgery (SRS) for distant brain metastases has been demonstrated as a safe and effective approach for intracranial recurrences after initial SRS. However, accurate tumor detection and segmentation among responding tumors within the irradiated parenchyma can be challenging. The requirement for the registration and reference to the previous course of SRS is very time-consuming and suffers significant inter and intra-reader variability. Artificial intelligence (AI)-assisted system has been proven to improve the accuracy and efficiency in the clinical flow of de-novo SRS. We hypothesize that an integrated AI system can facilitate an automated tumor contouring process for repeated SRS.

MATERIALS/METHODS

Three patients who underwent their third course of SRS to brain metastases were selected for the pioneering works. They have had two sessions of SRS with a mean lesion number of 4 and 3.7, respectively. VBrain, an FDA-approved brain tumor management AI platform, was used to co-registered serial MR scans and automatically identify, track, and contour brain metastases for each course of SRS. The AI also indicated new lesions and treated lesions for each course. Three radiation oncologists experienced in brain SRS contoured the gross tumor volumes (GTVs) of the third course of SRS in two reader modes (assisted then unassisted) with a memory washout period of one week between each section. The segmentation ground truth was established through consensus among the three experts. Lesion-wise sensitivity, contouring accuracy, and consuming time were compared between the two contouring modes.

RESULTS

In each patient, there were 15, 11, and 9 metastases, with a median diameter of 4.72 (95% CI: 4.05, 6.91) mm. The mean lesion-wise sensitivity was 96.96±2.47% with AI assistance and 76.90 ± 7.10% without assistance. There were two false-positive lesions in the assisted read, resulting in a low average false-positive rate of 0.67 per patient, while no false positive for the unassisted mode. AI assistance improved contouring accuracy. The median Dice similarity coefficient (DSC) was 0.71 (95% CI: 0.55, 0.87) for assisted contouring and 0.65 (95% CI: 0.46, 0.85) for unassisted contouring. We also use average Hausdorff distance (HD) to measure segmentation results. The mean HD was 0.72± 0.13 mm versus 0.73±0.08 mm for the two contouring modes (p = 0.02) Furthermore, the median contouring time per case was significantly shorter with AI assistance than without assistance (20.8 minutes vs. 29.8 minutes; p < 0.001), corresponding to a 43.2% time-saving.

CONCLUSION

Our results suggest that the integration of an AI-based system into repeated brain SRS can significantly improve the accuracy and efficiency of tumor detection and segmentation. This approach has the potential to streamline the treatment planning process for salvage SRS.

Liposome-tethered supported lipid bilayer platform for capture and release of heterogeneous populations of circulating tumor cells

Because of scarcity, vulnerability, and heterogeneity in the population of circulating tumor cells (CTCs), the CTC isolation system relying on immunoaffinity interaction exhibits inconsistent efficiencies for all types of cancers and even CTCs with different phenotypes in individuals. Moreover, releasing viable CTCs from an isolation system is of importance for molecular analysis and drug screening in precision medicine, which remains a challenge for current systems. In this work, a new CTC isolation microfluidic platform was developed and contains a coating of the antibody-conjugated liposome-tethered-supported lipid bilayer in a developed chaotic-mixing microfluidic system, referred to as the "LIPO-SLB" platform. The biocompatible, soft, laterally fluidic, and antifouling properties of the LIPO-SLB platform offer high CTC capture efficiency, viability, and selectivity. We successfully demonstrated the capability of the LIPO-SLB platform to recapitulate different cancer cell lines with different antigen expression levels. In addition, the captured CTCs in the LIPO-SLB platform can be detached by air foam to destabilize the physically assembled bilayer structures due to a large water/air interfacial area and strong surface tension. More importantly, the LIPO-SLB platform was constructed and used for the verification of clinical samples from 161 patients with different primary cancer types. The mean values of both single CTCs and CTC clusters correlated well with the cancer stages. Moreover, a considerable number of CTCs were isolated from patients' blood samples in the early/localized stages. The clinical validation demonstrated the enormous potential of the universal LIPO-SLB platform as a tool for prognostic and predictive purposes in precision medicine.

Multiomic characterization and drug testing establish circulating tumor cells as an ex vivo tool for personalized medicine

Matching the treatment to an individual patient’s tumor state can increase therapeutic efficacy and reduce tumor recurrence. Circulating tumor cells (CTCs) derived from solid tumors are promising subjects for theragnostic analysis. To analyze how CTCs represent tumor states, we established cell lines from CTCs, primary and metastatic tumors from a mouse model and provided phenotypic and multiomic analyses of these cells. CTCs and metastatic cells, but not primary tumor cells, shared stochastic mutations and similar hypomethylation levels at transcription start sites. CTCs and metastatic tumor cells shared a hybrid epithelial/mesenchymal transcriptome state with reduced adhesive and enhanced mobilization characteristics. We tested anti-cancer drugs on tumor cells from a metastatic breast cancer patient. CTC responses mirrored the impact of drugs on metastatic rather than primary tumors. Our multiomic and clinical anti-cancer drug response results reveal that CTCs resemble metastatic tumors and establish CTCs as an ex vivo tool for personalized medicine.

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Primary, CTC and metastatic cell lines from mouse models were directly compared

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Multiomic and phenotypic data indicate circulating cells resemble metastatic cells

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CTCs and metastasis tumors from a patient similarly respond to anti-cancer drugs

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CTCs are thus potentially useful for screening individual patient drug responses

Polycarboxybetaine-Based Hydrogels for the Capture and Release of Circulating Tumor Cells

Circulating tumor cells (CTCs) are indicators for the detection, diagnosis, and monitoring of cancers and offer biological information for the development of personalized medicine. Techniques for the specific capture and non-destructive release of CTCs from millions of blood cells remain highly desirable. Here, we present a CTC capture-and-release system using a disulfide-containing poly(carboxybetaine methacrylate) (pCB) hydrogel. The non-fouling characteristic of pCB prevents unwanted, nonspecific cell binding, while the carboxyl functionality of pCB is used for the conjugation of anti-epithelial cell adhesion molecule (anti-EpCAM) antibodies for the capture of CTCs. The results demonstrated that the anti-EpCAM-conjugated pCB hydrogel captured HCT116 cells from blood, and the capture ratio reached 45%. Furthermore, the captured HCT116 cells were released within 30 min from the dissolution of the pCB hydrogel by adding cysteine, which breaks the disulfide bonds of the crosslinkers. The cells released were viable and able to grow. Our system has potential in the development of a device for CTC diagnosis.

Early Detection and Dynamic Changes of Circulating Tumor Cells in Transgenic NeuN Transgenic (NTTg) Mice with Spontaneous Breast Tumor Development

Simple Summary

This study aimed to prove the early presence of circulating tumor cells (CTCs) with viability and tumorigenesis in a murine model that spontaneously develops breast cancer. Serial CTC examinations were performed on NeuN transgenic mice, starting from the age of 8 weeks and continuing after palpable tumor formation. Prior to the detection of palpable tumors, the CTC counts rose over time from 1 ± 1.6 to 16 ± 9.5 per 75 μL; this number continued to grow with tumor development. The viability and tumorigenesis of the collected CTCs were confirmed by re-implanting the cells into a non-cancer-bearing mouse. Ultrasonography with Doppler showed a significant correlation between CTCs and tumor vascular density (p-value < 0.01), rather than tumor volume (p-value 0.076).

Abstract

Background: This study used NeuN transgenic (NTTg) mice with spontaneous breast tumor development to evaluate the dynamic changes of circulating tumor cells (CTCs) prior to and during tumor development. Methods: In this longitudinal, clinically uninterrupted study, we collected 75 μL of peripheral blood at the age of 8, 12, 16, and 20 weeks in the first group of five mice, and at the age of 32 weeks, the time of tumor palpability, and one week after tumor palpability in the second group of four mice. Diluted blood samples were run through a modified mouse-CMx chip to isolate the CTCs. Results: The CTC counts of the first group of mice were low (1 ± 1.6) initially. The average CTC counts were 16 ± 9.5, 29.0 ± 18.2, and 70.0 ± 30.3 cells per 75 μL blood at the age of 32 weeks, the time of tumor palpability, and one week after tumor palpability, respectively. There was a significant positive correlation between an increase in CTC levels and tumor vascular density (p-value < 0.01). This correlation was stronger than that between CTC levels and tumor size (p-value = 0.076). The captured CTCs were implanted into a non-tumor-bearing NTTg mouse for xenografting, confirming their viability and tumorigenesis. Conclusion: Serial CTCs during an early stage of tumor progression were quantified and found to be positively correlated with the later tumor vascular density and size. Furthermore, the successful generation of CTC-derived xenografts indicates the tumorigenicity of this early onset CTC population.

Anticlogging Hemofiltration Device for Mass Collection of Circulating Tumor Cells by Ligand-Free Size Selection

A new hemofiltration system was developed to continuously capture circulating tumor cells (CTCs) from a large volume of whole blood using a column that was packed with antifouling zwitterionized silica microspheres. The silica microspheres were modified with sulfobetaine silane (SBSi) to inhibit fouling, resist clogging, and give a high surface wettability and prolonged operation time. Packed microspheres with different diameters formed size-controllable interstitial pores that effectively captured CTCs by ligand-free size selection. For optimized performance of the hemofiltration system, operational factors, including the size of microspheres, flow rate, and cross-sectional area of the column, were considered with respect to the removal rate for colorectal cancer cells and the retention rate for white blood cells and red blood cells. The captured CTCs were collected from the column by density sedimentation. A large quantity of colorectal cancer cells was spiked into sheep blood, and the sample was circulated for 5 h with a total operational volume of 2 L followed by collection and culture in vitro. The results showed that the proposed hemofiltration device selectively removed abundant CTCs from in vitro circulatory blood. The viable cells were harvested for amplification and potential applications for precision medicine.

Abstract B14: Artificial intelligence assists automation and high performance of circulating tumor cells enumeration and circulating tumor microemboli characterization in fluorescence microscopy images

Analysis of circulating tumor cells (CTCs) provides exclusive benefits compared with other liquid biopsy techniques due to their advanced clinical applications including single-cell multiomics (DNA, RNA, proteins, and metabolites) analysis and the ability to generate CTCs-derived xenograft models. Current CTC analysis primarily relies on labor-intensive and human-biased manual CTC enumeration or semiautomated work, hindering clinical adaptation of CTC analysis into practice. Beyond CTC enumeration, recent studies focused on detection and characterized features of circulating tumor microemboli (CTM) to improve cancer monitoring and diagnosis, but the added complexity of CTM makes CTC analysis even more challenging. Development of an automated, unbiased, and specialized computation method for CTC analysis remains a clinical unmet need. We developed a deep learning-based framework by applying computer vision to efficiently automate CTC enumeration and characterization with high throughput and accuracy. Fluorescence microscopy CTCs images (CK+/CD45-/DAPI+) have been prepared from blood samples of non-small cell lung cancer patients by the “CMx” CTC capture platform. This study applied an “active learning” model that only requires a small upfront training dataset while being able to accumulate more training data to make improvements with minimal annotation efforts. We have collected 20 images annotated by subject matter experts to train the initial model. Using an iterative process where feedback from the subject matter experts was used to influence the model, we achieved continuous improvements using adaptive annotations. After the model had been well trained and validated by 4 extra images, we used 18 new test images to benchmark the model performance. Preliminary results demonstrated that our AI model outperformed current semiautomated methods having higher sensitivity and reduced time for CTC enumeration in a lung cancer CTC sample analysis. In 18 test samples, the model predicted 34% more total CTCs than the current method (1,775 versus 1,328 counts). By applying the model to the 24 training samples, the model also recovered 45% more total CTCs absent from the original human annotation (2,507 versus 1,732 counts). In some samples, enumeration assisted by the model saved 90% of time over the current method (&lt;20 min vs ~4 hrs.) for CTC enumeration, which would result in an enormous advantage if the datasets being analyzed included a large number of samples. Furthermore, our AI model was able to characterize features of CTM, including CTC clusters and CTC-associated immune cells, in addition to enumerating the samples. The AI model developed in this study is a promising method for CTC analysis that significantly improved throughput, accuracy, and reproducibility, leading to an approach of CTC analysis better suited for clinical adoption. Development of AI-driven CTC/CTM analysis provides additional resources and advancements to the field of liquid biopsy for the diagnosis and treatment of disease.

Citation Format: Wei-Lei Yang, Chi-Bin Li, Jia-Yang Chen, Samuel Chen, Ten-Jen Liu, Ying-Chih Chang. Artificial intelligence assists automation and high performance of circulating tumor cells enumeration and circulating tumor microemboli characterization in fluorescence microscopy images [abstract]. In: Proceedings of the AACR Special Conference on Advances in Liquid Biopsies; Jan 13-16, 2020; Miami, FL. Philadelphia (PA): AACR; Clin Cancer Res 2020;26(11_Suppl):Abstract nr B14.

A two-dimensional immunomagnetic nano-net for the efficient isolation of circulating tumor cells in whole blood

An immunomagnetic "nano-net" was designed and synthesized for specifically capturing rare cells of interest from mixtures. The nano-net, Ab@Lipo-MNP-GO, consists of conjugated antibody molecules on a lipid coated magnetic nanoparticle-graphene oxide sheet complex. The magnetism, chemical composition, and the morphology of the construct and its precursors were characterized by SQUID, FTIR, TGA, DLS and SEM, to confirm the feasibility of the synthetic steps and the resulting properties suitable for solution phase immuno-recognition for cell capture. When applied to capturing circulating tumor cells (CTCs) in oral, colon and lung cancer clinical patients' blood samples, the nano-net construct exhibited far superior ability whereas conventional immunomagnetic beads in some cases were unable to capture any CTCs, even by increasing the bead concentration. Confocal images showed that the nano-net wrapped around the CTCs while the immunomagnetic beads attached them with point contacts. A stable, patch-like multivalent matrix nano-net was demonstrated to tackle the shortcomings of single point contact of immunomagnetic beads to the target cell. This strategy is universal for any cell separation in complex fluids.

[Changes of BK(Ca) on vascular striaepericytes of D-galactose-induced aging model in guinea pigs]

Objective: The aging model of guinea pigs induced by D-galactose was set up to investigate the changes of BK(Ca) expression and function on cochlear pericytes and their relationship with age-related hearing loss. Methods: Thirty healthy 8-week-old guinea pigs were randomly divided into three groups, with 10 in each group: D-galactose aging model group, subcutaneous injection of D-galactose (500 mg/kg) daily for 6 weeks; saline control group, the same amount of saline was injected into the neck of the aging model group for 6 weeks; the blank control group, no treatment was performed. The threshold of auditory brainstem response (ABR) was detected. The content of BK(Ca) in the perivascular cells of the guinea pig cochlear cells was detected by immunofluorescence technique. The changes of peripheral current density and BK(Ca) current were detected by patch clamp technique. The data were analyzed by GraphPad Prism software. Results: Compared with the saline group and the control group, the ABR threshold and the amplitude of the wave I were significantly decreased in the aging model group, and the difference was statistically significant (P<0.01). Compared with the control group, the expression of BK(Ca) in the vascular pericytes of guinea pigs in the aging model group was significantly reduced (1.00±0.08 vs 0.27±0.03,the difference was statistically significant P<0.01), and the cell current density and BK(Ca) net current value were also significantly reduced with statistically significant (P<0.01). Conclusions: D-galactose can successfully induce guinea pig aging model, in which BK(Ca) expression decreases and net current value decreases in pericytes of cochlear striavascularis, and changes in BK(Ca) expression and function may be related to age-related hearing loss.

Random and aligned electrospun PLGA nanofibers embedded in microfluidic chips for cancer cell isolation and integration with air foam technology for cell release

BACKGROUND

Circulating tumor cells (CTCs) comprise the high metastatic potential population of cancer cells in the blood circulation of humans; they have become the established biomarkers for cancer diagnosis, individualized cancer therapy, and cancer development. Technologies for the isolation and recovery of CTCs can be powerful cancer diagnostic tools for liquid biopsies, allowing the identification of malignancies and guiding cancer treatments for precision medicine.

METHODS

We have used an electrospinning process to prepare poly(lactic-co-glycolic acid) (PLGA) nanofibrous arrays in random or aligned orientations on glass slips. We then fabricated poly(methyl methacrylate) (PMMA)-based microfluidic chips embedding the PLGA nanofiber arrays and modified their surfaces through sequential coating with using biotin-(PEG)7-amine through EDC/NHS activation, streptavidin (SA), and biotinylated epithelial-cell adhesion-molecule antibody (biotin-anti-EpCAM) to achieve highly efficient CTC capture. When combined with an air foam technology that induced a high shear stress and, thereby, nondestructive release of the captured cells from the PLGA surfaces, the proposed device system operated with a high cell recovery rate.

RESULTS

The morphologies and average diameters of the electrospun PLGA nanofibers were characterized using scanning electron microscopy (SEM) and confocal Raman imaging. The surface chemistry of the PLGA nanofibers conjugated with the biotin-(PEG)7-amine was confirmed through time-of-flight secondary ion mass spectrometry (ToF-SIMS) imaging. The chip system was studied for the effects of the surface modification density of biotin-(PEG)7-amine, the flow rates, and the diameters of the PLGA nanofibers on the capture efficiency of EpCAM-positive HCT116 cells from the spiked liquid samples. To assess their CTC capture efficiencies in whole blood samples, the aligned and random PLGA nanofiber arrays were tested for their abilities to capture HCT116 cells, providing cancer cell capture efficiencies of 66 and 80%, respectively. With the continuous injection of air foam into the microfluidic devices, the cell release efficiency on the aligned PLGA fibers was 74% (recovery rate: 49%), while it was 90% (recovery rate: 73%) on the random PLGA fibers, from tests of 200 spiked cells in 2 mL of whole blood from healthy individuals. Our study suggests that integrated PMMA microfluidic chips embedding random PLGA nanofiber arrays may be suitable devices for the efficient capture and recovery of CTCs from whole blood samples.

Periorbital erythema and swelling as a presenting sign of lupus erythematosus in tertiary referral centers and literature review

Background Cutaneous lupus erythematosus (CLE) includes a broad range of dermatologic manifestations. Periorbital involvement, however, is a relatively rare clinical presentation of CLE. Objectives This clinical study aimed to investigate the characteristics of this unique presentation of CLE in tertiary medical centers. Methods We enrolled patients with periorbital erythema and swelling as the presenting sign of lupus erythematosus, from January 2003 to November 2017, using the data of 553 pathologically proven CLE cases from the registration database of the Chang Gung Memorial Hospitals in Taiwan. Results We enrolled a total of 25 patients. The mean age was 46.7 years and 68% of the patients were female. Most of the patients (84.0%) presented with unilateral involvement, with the left orbit involved in 15 patients (60%); the upper eyelid was the most frequently involved (72%). Mean duration between the onset of clinical manifestations and the diagnosis of CLE was approximately 59 weeks. Nineteen patients had been previously misdiagnosed. All patients had features compatible with CLE on histopathological examination. In contrast, laboratory analysis of the autoimmune profile often revealed negative results, including those for antinuclear antibodies (25%). Notably, anti-SSA/SSB (45.5%) showed the highest positive rate. During follow-up, six patients developed systemic lupus erythematosus (SLE) and two patients developed Sjögren syndrome. Conclusions The diagnosis of CLE presenting as periorbital erythema and swelling is often delayed because of clinical mimicry and the high proportion of negative results on autoantibody tests. Increased clinical suspicion and prompt histopathological examination are crucial for early diagnosis. Moreover, one-fourth of the patients ultimately developed SLE, which highlights the importance of clinical awareness.

Identifying cancer origin using circulating tumor cells

Circulating tumor cells (CTCs) have become an established clinical evaluation biomarker. CTC count provides a good correlation with the prognosis of cancer patients, but has only been used with known cancer patients, and has been unable to predict the origin of the CTCs. This study demonstrates the analysis of CTCs for the identification of their primary cancer source. Twelve mL blood samples were equally dispensed on 6 CMx chips, microfluidic chips coated with an anti-EpCAM-conjugated supported lipid bilayer, for CTC capture and isolation. Captured CTCs were eluted to an immunofluorescence (IF) staining panel consisting of 6 groups of antibodies: anti-panCK, anti-CK18, anti-CK7, anti-TTF-1, anti-CK20/anti-CDX2, and anti-PSA/anti-PSMA. Cancer cell lines of lung (H1975), colorectal (DLD-1, HCT-116), and prostate (PC3, DU145, LNCaP) were selected to establish the sensitivity and specificity for distinguishing CTCs from lung, colorectal, and prostate cancer. Spiking experiments performed in 2mL of culture medium or whole blood proved the CMx platform can enumerate cancer cells of lung, colorectal, and prostate. The IF panel was tested on blood samples from lung cancer patients (n = 3), colorectal cancer patients (n = 5), prostate cancer patients (n = 5), and healthy individuals (n = 12). Peripheral blood samples found panCK⁺ and CK18⁺ CTCs in lung, colorectal, and prostate cancers. CTCs expressing CK7⁺ or TTF-1⁺, (CK20/ CDX2)⁺, or (PSA/ PSMA)⁺ corresponded to lung, colorectal, or prostate cancer, respectively. In conclusion, we have designed an immunofluorescence staining panel to identify CTCs in peripheral blood to correctly identify cancer cell origin.

Microfluidic Capture and Multiplex Immunofluorescence of Circulating Tumor Cells to Identify Cancer of Origin

Circulating tumor cells (CTCs) are an important biomarker and their analysis can be considered a form of "liquid biopsy." The purpose of this book chapter is to describe the use of the 4-channel CMx (cells captured in maximum) microfluidic chip, containing special micropatterns coated with an antibody-conjugated supported lipid bilayer (SLB) on its surface, to capture and isolate CTCs from the blood of cancer patients. Captured CTCs are subsequently released by an air foam to an immunofluorescence (IF) staining panel that enables further analysis, including the identification of the primary cancer source of the CTCs.

Site-specific antibody modification and immobilization on a microfluidic chip to promote the capture of circulating tumor cells and microemboli

Antibody coating via Fc-domain site-specific immobilization improves capture efficiency of circulating tumor cells and microemboli in microfluidics.

Meta-analysis of cardiovascular toxicity risks in cancer patients on selected targeted agents

PURPOSE

The purpose was to estimate the risk and severity of cardiovascular toxicities associated with selected targeted agents.

METHODS

We searched English-language literature for randomized clinical trials published between January 1, 2000 and November 30, 2013 of targeted cancer therapy drugs approved by the FDA by November 2010. One hundred ten studies were eligible. Using meta-analytic methods, we calculated the relative risks of several cardiovascular toxicities [congestive heart failure (CHF), decreased left ventricular ejection fraction (DLVEF), myocardial infarction (MI), arrhythmia, and hypertension (HTN)], adjusting for sample size using the inverse-variance technique. For each targeted agent and side effect, we calculated the number needed to harm.

RESULTS

Regarding CHF, trastuzumab showed significantly greater risk of all-grade and high-grade CHF. There was significant increased risk of all-grade DLVEF with sorafenib, sunitinib, and trastuzumab and high-grade DLVEF with bevacizumab and trastuzumab. Sorafenib was associated with significant increased all-grade risk of MI based on one study. None was associated with high-grade risk of MI or increased risk of arrhythmia. Bevacizumab, sorafenib, and sunitinib had significant increased risk of all-grade and high-grade HTN.

CONCLUSIONS

Several of the targeted agents were significantly associated with increased risk of specific cardiovascular toxicities, CHF, DLVEF, and HTN. Several had significant increased risk for high-grade cardiovascular toxicities (CHF, DLVEF, and HTN). Patients receiving such therapy should be closely monitored for these toxicities and early and aggressive treatment should occur. However, clinical experience has demonstrated that some of these toxicities may be reversible and due to secondary effects.

Clinical Significance of Circulating Tumor Microemboli as a Prognostic Marker in Patients with Pancreatic Ductal Adenocarcinoma

BACKGROUND

Characterization of circulating tumor cells (CTCs) has been used to provide prognostic, predictive, and pharmacodynamic information in many different cancers. However, the clinical significance of CTCs and circulating tumor microemboli (CTM) in patients with pancreatic ductal adenocarcinoma (PDAC) has yet to be determined.

METHODS

In this prospective study, CTCs and CTM were enumerated in the peripheral blood of 63 patients with PDAC before treatment using anti-EpCAM (epithelial cell adhesion molecule)–conjugated supported lipid bilayer–coated microfluidic chips. Associations of CTCs and CTM with patients' clinical factors and prognosis were determined.

RESULTS

CTCs were abundant [mean (SD), 70.2 (107.6)] and present in 81% (51 of 63) of patients with PDAC. CTM were present in 81% (51 of 63) of patients with mean (SD) 29.7 (1101.4). CTM was an independent prognostic factor of overall survival (OS) and progression free survival (PFS). Patients were stratified into unfavorable and favorable CTM groups on the basis of CTM more or less than 30 per 2 mL blood, respectively. Patients with baseline unfavorable CTM, compared with patients with favorable CTM, had shorter PFS (2.7 vs 12.1 months; P &lt; 0.0001) and OS (6.4 vs 19.8 months; P &lt; 0.0001). Differences persisted if we stratified patients into early and advanced diseases. The number of CTM before treatment was an independent predictor of PFS and OS after adjustment for clinically significant factors.

CONCLUSIONS

The number of CTM, instead of CTCs, before treatment is an independent predictor of PFS and OS in patients with PDAC.

An energy adjustable linearly polarized passively Q-switched bulk laser with a wedged diffusion-bonded Nd:YAG/Cr⁴⁺:YAG crystal

An energy adjustable passively Q-switched laser is demonstrated with a composite Nd:YAG/Cr⁴⁺:YAG crystal by applying a wedged interface inside the crystal. The theoretical model of the monolithic laser resonator is explored to show the energy adjustable feature with different initial transmissions of the saturable absorber at the horizontal axis. By adjusting the pump beam location across the Nd:YAG crystal, the output pulse energy can be flexibly changed from 10.9 μJ to 17.6 μJ while maintaining the same output efficiency. The polarization state of the laser output is found to be along with the polarization of the C-mount pump diode. Finally, the behavior of the multi-transverse-mode oscillation is also discussed for eliminating the instability of the pulse train.

Chemoresponsive surface-tethered polypeptide brushes based on switchable secondary conformations

Surface-tethered chemoresponsive polypeptides prepared by surface-initiated vapor deposition polymerization were used to investigate conversion efficiency between α-helical and β-sheet conformations.

Promoting the selection and maintenance of fetal liver stem/progenitor cell colonies by layer-by-layer polypeptide tethered supported lipid bilayer

In this study, we designed and constructed a series of layer-by-layer polypeptide adsorbed supported lipid bilayer (SLB) films as a novel and label-free platform for the isolation and maintenance of rare populated stem cells. In particular, four alternative layers of anionic poly-l-glutamic acid and cationic poly-l-lysine were sequentially deposited on an anionic SLB. We found that the fetal liver stem/progenitor cells from the primary culture were selected and formed colonies on all layer-by-layer polypeptide adsorbed SLB surfaces, regardless of the number of alternative layers and the net charges on those layers. Interestingly, these isolated stem/progenitor cells formed colonies which were maintained for an 8 day observation period. Quartz crystal microbalance with dissipation measurements showed that all SLB-polypeptide films were protein resistant with serum levels significantly lower than those on the polypeptide multilayer films without an underlying SLB. We suggest the fluidic SLB promotes selective binding while minimizing the cell-surface interaction due to its nonfouling nature, thus limiting stem cell colonies from spreading.

YM155 down-regulates survivin and XIAP, modulates autophagy and induces autophagy-dependent DNA damage in breast cancer cells

BACKGROUND AND PURPOSE

The aim of this study was to determine the potency and molecular mechanism of action of YM155, a first-in-class survivin inhibitor that is currently under phase I/II clinical investigations, in various drug-resistant breast cancers including the oestrogen receptor positive (ER(+) ) tamoxifen-resistant breast cancer and the caspase-3-deficient breast cancer.

EXPERIMENTAL APPROACH

The potency of YM155 in SK-BR-3, MDA-MB-231, MCF7 and its tamoxifen-resistant sublines, TamR6, TamR7, TamR8, TamC3 and TamC6, were determined by MTT assay. Western blot analysis, flow cytometric analysis, reverse transcription-PCR, fluorescent microscopy and comet assay were used to determine the molecular mechanism of action of YM155 in different breast cancer cell lines.

KEY RESULTS

YM155 was equally potent towards the parental ER(+) /caspase-3-deficient MCF7 breast cancer cells and its tamoxifen-resistant sublines in vitro. The ER(-) /HER2(+) SK-BR-3 breast cancer cells and the triple-negative/caspase-3-expressing metastatic aggressive MDA-MB-231 breast cancer cells were also sensitive to YM155 with IC50 values in the low nanomolar range. Targeting survivin by YM155 modulated autophagy, induced autophagy-dependent caspase-7 activation and autophagy-dependent DNA damage in breast cancer cells. Interestingly, YM155 also induced XIAP degradation and the degradation of XIAP might play an important role in YM155-induced autophagy in breast cancer cells.

CONCLUSIONS AND IMPLICATIONS

YM155 is a potent survivin inhibitor that has potential for the management of various breast cancer subtypes regardless of the expression of ER, HER2 and caspase-3. Importantly, this study provides new insights into YM155's molecular mechanism of action and therapeutic potential in the treatment of tamoxifen-resistant breast cancer.

Developing antifouling biointerfaces based on bioinspired zwitterionic dopamine through pH-modulated assembly

The use of synthetic biomaterials as implantable devices typically is accompanied by considerable nonspecific adsorption of proteins, cells, and bacteria. These may eventually induce adverse pathogenic problems in clinical practice, such as thrombosis and biomaterial-associated infection. Thus, an effective surface coating for medical devices has been pursued to repel nonspecific adsorption from surfaces. In this study, we employ an adhesive dopamine molecule conjugated with zwitterionic sulfobetaine moiety (SB-DA), developed based on natural mussels, as a surface ligand for the modification of TiO2. The electrochemical study shows that the SB-DA exhibits fully reversible reduction-oxidation behavior at pH 3, but it is irreversible at pH 8. A contact angle goniometer and X-ray photoelectron spectroscopy were utilized to explore the surface hydration, chemical states, and bonding mechanism of SB-DA. The results indicate that the binding between hydroxyl groups of SB-DA and TiO2 converts from hydrogen bonds to bidentate binding upon the pH transition from pH 3 to 8. In order to examine the antifouling properties of SB-DA thin films, the modified substrates were brought into contact with bovine serum albumin and bacteria solutions. The fouling levels were monitored using a quartz crystal microbalance with dissipation sensor and fluorescence optical microscope. Tests showed that the sample prepared via the pH transition approach provides the best resistance to nonspecific adsorption due to the high coverage and stability of the SB-DA films. These findings support the mechanism of the pH-modulated assembly of SB-DA molecules, and for the first time we demonstrate the antifouling properties of the SB-DA to be comparable with traditional thiol-based zwitterionic self-assemblies. The success of modification with SB-DA opens an avenue for developing a biologically inspired surface chemistry and can have applications over a wide spectrum of bioapplications. The strategy of the pH transition can also be applied to other functional dopamine derivatives.

Differentiation of neural stem/progenitor cells using low-intensity ultrasound

Herein, we report the evaluation of apoptosis, cell differentiation, neurite outgrowth and differentiation of neural stem/progenitor cells (NSPCs) in response to low-intensity ultrasound (LIUS) exposure. NSPCs were cultured under different conditions, with and without LIUS exposure, to evaluate the single and complex effects of LIUS. A lactic dehydrogenase assay revealed that the cell viability of NSPCs was maintained with LIUS exposure at an intensity range from 100 to 500 mW/cm(2). Additionally, in comparison with no LIUS exposure, the cell survival rate was improved with the combination of medium supplemented with nerve growth factor and LIUS exposure. Our results indicate that LIUS exposure promoted NSPC attachment and differentiation on a glass substrate. Neurite outgrowth assays revealed the generation of longer, thicker neurites after LIUS exposure. Furthermore, LIUS stimulation substantially increased the percentage of differentiating neural cells in NSPCs treated with nerve growth factor in comparison with the unstimulated group. The high percentage of differentiated neural cells indicated that LIUS induced neuronal networks denser than those observed in the unstimulated groups. Furthermore, the release of nitric oxide, an important small-molecule neurotransmitter, was significantly upregulated after LIUS exposure. It is therefore reasonable to suggest that LIUS promotes the differentiation of NSPCs into neural cells, induces neurite outgrowth and regulates nitric oxide production; thus, LIUS may be a potential candidate for NSPC induction and neural cell therapy.

Efficient elusion of viable adhesive cells from a microfluidic system by air foam

We developed a new method for releasing viable cells from affinity-based microfluidic devices. The lumen of a microchannel with a U-shape and user-designed microstructures was coated with supported lipid bilayers functionalized by epithelial cell adhesion molecule antibodies to capture circulating epithelial cells of influx solution. After the capturing process, air foam was introduced into channels for releasing target cells and then carrying them to a small area of membrane. The results show that when the air foam is driven at linear velocity of 4.2 mm/s for more than 20 min or at linear velocity of 8.4 mm/s for more than 10 min, the cell releasing efficiency approaches 100%. This flow-induced shear stress is much less than the physiological level (15 dyn/cm(2)), which is necessary to maintain the intactness of released cells. Combining the design of microstructures of the microfluidic system, the cell recovery on the membrane exceeds 90%. Importantly, we demonstrate that the cells released by air foam are viable and could be cultured in vitro. This novel method for releasing cells could power the microfluidic platform for isolating and identifying circulating tumor cells.

Evaluation of the effects of nanoscale zero-valent iron (nZVI) dispersants on intrinsic biodegradation of trichloroethylene (TCE)

In this study, the biodegradability of nanoscale zero-valent iron (nZVI) dispersants and their effects on the intrinsic biodegradation of trichloroethylene (TCE) were evaluated. Results of a microcosm study show that the biodegradability of three dispersants followed the sequence of: polyvinyl alcohol-co-vinyl acetate-co-itaconic acid (PV3A) > polyoxyethylene (20) sorbitan monolaurate (Tween 20) > polyacrylic acid (PAA) under aerobic conditions, and PV3A > Tween 20 > PAA under anaerobic conditions. Natural biodegradation of TCE was observed under both aerobic and anaerobic conditions. No significant effects were observed on the intrinsic biodegradation of TCE under aerobic conditions with the presence of the dispersants. The addition of PAA seemed to have a slightly adverse impact on anaerobic TCE biodegradation. Higher accumulation of the byproducts of anaerobic TCE biodegradation was detected with the addition of PV3A and Tween 20. The diversity of the microbial community was enhanced under aerobic conditions with the presence of more biodegradable PV3A and Tween 20. The results of this study indicate that it is necessary to select an appropriate dispersant for nZVI to prevent a residual of the dispersant in the subsurface. Additionally, the effects of the dispersant on TCE biodegradation and the accumulation of TCE biodegrading byproducts should also be considered.

In situ Surface Tailoring with Zwitterionic Carboxybetaine Moieties on Self-Assembled Thin Film for Antifouling Biointerfaces

A novel biointerface bearing zwitterionic carboxybetaine moieties was developed for effective resistance to nonspecific adsorption of proteins and blood cells. Self-assembled thin films (SAFs) of (N,N-dimethylaminopropyl) trimethoxysilane were formed as mattress layers by either vapor or solution deposition. Subsequently, the tertiary amine head groups on SAFs were reacted with β-propiolactone to give zwitterionic carboxybetaine moieties via in situ synthesis. The optimal reaction time of 8 h for both preparation methods was verified by static contact angle measurements. According to the X-ray photoelectron spectroscopy, 67.3% of amine groups on SAFs prepared from the vapor deposition was converted to the zwitterionic structures after reaction of β-propiolactone. The antifouling properties of the zwitterionic biointerfaces were quantitatively evaluated in the presence of protein solutions using a quartz crystal microbalance with dissipation, showing a great improvement by factors of 6.5 and 20.2 from tertiary amine SAFs and bare SiO₂ surfaces, respectively. More importantly, the zwitterionic SAFs were brought to contact with undiluted human blood in chaotic-mixer microfluidic systems; the results present their capability to effectively repel blood cell adhesion. Accordingly, in this work, development of carboxybetaine SAFs offers a facile yet effective strategy to fabricate biocompatible biointerfaces for a variety of potential applications in surface coatings for medical devices.

A semi-automated vascular access system for preclinical models

Murine models are used extensively in biological and translational research. For many of these studies it is necessary to access the vasculature for the injection of biologically active agents. Among the possible methods for accessing the mouse vasculature, tail vein injections are a routine but critical step for many experimental protocols. To perform successful tail vein injections, a high skill set and experience is required, leaving most scientists ill-suited to perform this task. This can lead to a high variability between injections, which can impact experimental results. To allow more scientists to perform tail vein injections and to decrease the variability between injections, a vascular access system (VAS) that semi-automatically inserts a needle into the tail vein of a mouse was developed. The VAS uses near infrared light, image processing techniques, computer controlled motors, and a pressure feedback system to insert the needle and to validate its proper placement within the vein. The VAS was tested by injecting a commonly used radiolabeled probe (FDG) into the tail veins of five mice. These mice were then imaged using micro-positron emission tomography to measure the percentage of the injected probe remaining in the tail. These studies showed that, on average, the VAS leaves 3.4% of the injected probe in the tail. With these preliminary results, the VAS system demonstrates the potential for improving the accuracy of tail vein injections in mice.

A fractal dimensional approach to successful evaluation of apical healing

AIM

To evaluate whether the initial healing of apical radiolucencies 1 year after root canal treatment could be quantitatively identified by the change in fractal dimension (FD) values for the eventually completely healed cases.

METHODOLOGY

Twenty-six patients with successful root canal treatment were recruited. All teeth were associated with complete healing either before or at 1 year following treatment (six of 26) or still undergoing healing at 1 year after treatment but completely healed thereafter (20 of 26). Two radiographs were selected for the same patient, one taken before treatment and the other taken 1 year after treatment. Eight regions of interests (ROIs) were selected from each radiograph, two as the experimental group located close to the infected root apex, two as the control group in the healthy bone and the other four in the healthy bone ensuring the image quality.

RESULTS

Based on the FD values of the four ROIs in the healthy bone, the two radiographs were confirmed to have been taken with similar projection angles and exposure. The FD values were shown to significantly increase (P = 0.006) and decrease (P = 0.000) around the root apex and the neighbouring region of the apical lesion, respectively.

CONCLUSION

Changes in fractal dimension values may serve as a necessary condition to quantitatively indicate the initial healing status 1 year after root canal treatment.

Use of surface properties to control the growth and differentiation of mouse fetal liver stem/progenitor cell colonies

Multilayers of poly-l-lysine/poly-l-glutamic acid (PLL/PLGA) were constructed by layer-by-layer deposition on an end-tethered cationic PLL brush film serving as an initial layer. Increasing the number of coupling layers increased the thickness and the hydration of the films, and decreased the films' shear modulus and serum adsorption. These films were used to culture primary mouse fetal liver cells. Fetal liver stem/progenitor cells (FLSPCs) were isolated and maintained on the PLGA-terminal PLL/PLGA surfaces, forming colonies with clear boundaries that were partially attached to the surface, with cross-sectional areas of ~500 to ~2500 μm(2) after 2 days culture. Long-term studies showed that the cluster size of colonies slowly expanded and was correlated with the surface properties. For example, on the thicker films with shear modulus, G, less than 5 kPa, FLSPCs cluster size was constrained within a small distribution with less than 4000 μm(2) of projected area, whereas on the thinner films with G > 30 kPa, clusters were expanded and widely distributed, with projected areas over 4000 um(2). Immunostaining studies suggested that clusters with a small size maintained the self-renewal characteristics of stem cells, while the expanded clusters were clearly the results of spontaneous differentiation, exhibiting hepatocyte-like properties. On PLL-terminal t-(PLL/PLGA) films, which are less favorable for stem cell cultures than PLGA-terminal t-(PLL/PLGA) films, the cluster size distribution was also correlated with the film thickness, with more clusters of small size preserved on the thicker films. We observed that a soft, hydrated, serum-free surface could restrict the FLSPC expansion, resulting in self-maintenance of FLSPC colonies.

Tethered fibronectin liposomes on supported lipid bilayers as a prepackaged controlled-release platform for cell-based assays

A biomimetic construct containing an extracellular matrix protein-liposome composite tethered on supported lipid bilayers (SLBs) was formed with fibronectin (FN), and polyethylene glycol (PEG) and cholesterol-containing liposomes. The construct can serve as a multifunctional platform for cell attachment and drug release. The successful fabrication of the FN-liposome-SLB model platform was analyzed in situ with a quartz crystal microbalance with dissipation. The long-term stability of the surface tethered liposomes was measured via an encapsulated fluorescent probe. Less than 20% of the fluorescent probe content was released in 8 days, which compared favorably to the release of 90% of the probe content in one day from a similar construct made without PEG and cholesterol. HeLa cells were used to study the cellular interactions with the model platform. The extracellular matrix composition, FN, was found to be essential to promote HeLa cell adhesion on the liposome-SLB surfaces. Upon cell adhesion, the liposomes were spatially reorganized and absorbed by the cells. The rate of HeLa cell apoptosis was correlated with the surface density of doxorubicin-loaded liposomes, confirming the effective drug delivery through liposomes. The multifunctional model platform could be useful as preadministered, controlled-release platforms for cell- and tissue-based assays.

Difficulties in organ procurement and transplantation in the aboriginal minority people in Taiwan

BACKGROUND

Aboriginal people (AP) are a minority group in Taiwan. Little information on their perspectives on organ transplantation (OT) is available. Their rights for organ donation (OD) and as OT recipients (OTR) are constrained as a vulnerable population in society. This research sought to explore various Highland Aborigine Tribes beliefs systems and concepts related to OT.

METHODS

We employed a qualitative design on a purposive sample including seven categories of Taiwanese AP. Data collected by face-to-face interviews were evaluated by content analysis.

RESULTS

Seventy-five informants (45 female and 30 males) of 18 to 82 years from seven tribes completed interviews: Bunun (n = 20), Shao (n = 18), Tsou (n = 15), Amis (n = 12), Truku (n = 4), Rukai (n = 3), and Puyuma (n = 3). Of there, 33% had no idea of OT. All informants reported lack of knowledge of OD, organ procurement, and OTR. Eighty percent (45-82 years) had no willingness for OD or OTR; others might consult family members and health professionals (HP) to learn about OT. Seven hindering factors were identified: (1) having no background of OT; (2) limited impressions obtained from television news reports; (3) negative concepts of donating one's organs to others; (4) OT concepts contrast with cultural meanings of death; (5) possibility of being stigmatized; (6) fear of being rejected by others; and (7) HP had never mentioned OT.

CONCLUSIONS

Taiwan APs' perspectives of OT concepts showed the majority to be unfamiliar with the concept and benefits of OT. Future research is necessary to explore the possible avenues to facilitate communications between HP and AP leaders, as well as elders in each AP category in Taiwan.

Homeobox genes in obsessive-compulsive disorder

BACKGROUND

Despite evidence that obsessive-compulsive disorder (OCD) is a familial neuropsychiatric condition, progress aimed at identifying genetic determinants of the disorder has been slow. The OCD Collaborative Genetics Study (OCGS) has identified several OCD susceptibility loci through linkage analysis.

METHODS

In this study we investigate two regions on chromosomes 15q and 1q by first refining the linkage region using additional short tandem repeat polymorphic (STRP) markers. We then performed association analysis on single nucleotide polymorphisms (SNP) genotyped (markers placed every 2-4 kb) in the linkage regions in the OCGS sample of 376 rigorously phenotyped affected families.

RESULTS

Three SNPs are most strongly associated with OCD: rs11854486 (P = 0.00005 [0.046 after adjustment for multiple tests]; genetic relative risk (GRR) = 11.1 homozygous and 1.6 heterozygous) and rs4625687 [P = 0.00007 (after adjustment = 0.06); GRR = 2.4] on 15q; and rs4387163 (P = 0.0002 (after adjustment = 0.08); GRR = 1.97) on 1q. The first SNP is adjacent to NANOGP8, the second SNP is in MEIS2, and the third is 150 kb between PBX1 and LMX1A.

CONCLUSIONS

All the genes implicated by association signals are homeobox genes and are intimately involved in neurodevelopment. PBX1 and MEIS2 exert their effects by the formation of a heterodimeric complex, which is involved in development of the striatum, a brain region involved in the pathophysiology of OCD. NANOGP8 is a retrogene of NANOG, a homeobox transcription factor known to be involved in regulation of neuronal development. These findings need replication; but support the hypothesis that genes involved in striatal development are implicated in the pathogenesis of OCD.

Lifetime exposure to cigarette smoking and the development of adult-onset atopic dermatitis

BACKGROUND

Adult-onset atopic dermatitis (AD) has recently been recognized as a distinct disease entity, but its risk factors have not yet been clearly defined. Although gestational and perinatal exposure to tobacco smoking may be associated with the development of classic AD, the association between active/passive smoking and adult-onset AD remains controversial.

OBJECTIVES

To determine if exposure to smoking, including environmental tobacco smoke (ETS), is associated with the risk of adult-onset AD.

METHODS

Tobacco smoking and exposure to ETS were measured in a case-control association analysis in 83 patients with physician-diagnosed adult-onset AD and 142 age- and sex-matched controls.

RESULTS

Multiple logistic regression analyses showed that, among the potential environmental risk factors, both current and ever smoking were significant risk factors for adult-onset AD [odds ratio (OR) 4·994 and 3·619, respectively], compared with never smoking. Also, packs per year was significantly associated with adult-onset AD (OR 1·058, 95% confidence interval 1·028-1·089), suggesting a lifelong cumulative risk in current smokers. Moreover, nonsmokers with adult-onset AD reported significantly more exposure to ETS.

CONCLUSIONS

Early and/or current exposure to cigarette smoking may contribute cumulatively to the development of adult-onset AD. Exposure to ETS in childhood is associated with the development of adult-onset AD. Adults should be discouraged from smoking to prevent adult-onset AD in themselves and their family members.

The influence of collagen film nanostructure on pulmonary stem cells and collagen-stromal cell interactions

We have recently identified a rare subpopulation of lung colony cells with the characteristics of pulmonary stem cells, and discovered that stem cell colonies grew preferentially on type I collagen films in a serum-free medium. In order to further optimize culture conditions and determine stem cell growth in relation to microenvironments (including the stroma, medium and nanostructures of type I collagen films), both primary and pre-sorted stem cells were cultured on the type I collagen films with controllable degree of polymerization and film thickness, as confirmed by an atomic force microscope and surface profiler. We found that in a primary culture, the spreading of stromal cells is greatly restrained and both the size and number of colonies are significantly reduced on highly polymerized collagen films. In contrast, in a pre-sorted stem cell culture without stromal cells, the intrinsic stem cell properties and cell number are independent of the degree of collagen polymerization. Our results indicate that the nanostructures of type I collagen films primarily affect stem colony formation through the collagen-stroma interactions. In those cases, collagen film thickness shows no effect on colony formation.

The origin of the white Roman goose

In order to avoid interference from nuclear copies of mitochondrial DNA (numts), mtDNA of the white Roman goose (domestic goose) was extracted from liver mitochondria. The mtDNA control region was amplified using a long PCR strategy and then sequenced. Neighbor-joining, maximum parsimony, and maximum-likelihood approaches were implemented using the 1,177 bp mtDNA control region sequences to compute the phylogenetic relationships of the domestic goose with other geese. The resulting identity values for the white Roman geese were 99.1% (1,166/1,177) with western graylag geese and 98.8% (1,163/1,177) with eastern graylag geese. In molecular phylogenetic trees, the white Roman goose was grouped in the graylag lineage, indicating that the white Roman goose came from the graylag goose (Anser anser). Thus, the scientific name of the white Roman goose should be Anser anser 'White Roman.'

Type I collagen-functionalized supported lipid bilayer as a cell culture platform

The supported phospholipid bilayer serves as an important biomimetic model for the cell membrane in both basic and applied scientific research. We have constructed a biomimetic platform based on a supported phospholipid bilayer that is functionalized with type I collagen to serve as a substrate for cell culture. To create the type I collagen-functionalized lipid bilayer assembly, a simple chemical approach was employed: lipid vesicles composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphoethanolamine-N-(glutaryl) (DP-NGPE), a carboxylic acid-functionalized phospholipid, were prepared and then fused onto an SiO(2) substrate to form a supported lipid bilayer. Subsequently, type I collagen molecules were introduced to form stable collagen-lipid conjugates via amide linkages with activated DP-NGPE lipids. The binding kinetics of the conjugation process and the resultant changes in film thickness and viscoelasticity were followed using the quartz crystal microbalance with dissipation (QCM-D) monitoring. The morphology of the conjugated collagen adlayer was investigated with atomic force microscopy (AFM). We observed that the adsorbed collagen molecules tended to self-assemble into fibrillar structures. Fluorescence recovery after photobleaching (FRAP) was utilized to estimate lateral lipid mobility, which was reduced by up to 20% after the coupling of type I collagen to the underlying lipid bilayer. As a cell culture platform, the collagen-conjugated supported lipid bilayer showed promising results. Smooth muscle cells (A10) retained normal growth behavior on the collagen-functionalized platform, unlike the bare POPC lipid bilayer and the POPC/DG-NGPE bilayer without collagen. The biomimetic functionalized lipid system presented here is a simple, yet effective approach for constructing a cell culture platform to explore the interactions between extracellular matrix components and cells.

Lack of association between AKT1 variances versus clinical manifestations and social function in patients with schizophrenia

The elucidation of genotype-phenotype relationships in psychiatric research is at an early stage. V-akt murine thymoma viral oncogene homolog 1 (AKT1) is a serine/threonine kinase known as protein kinase B. Emerging studies have implicated the role of AKT1 in pathogenesis of schizophrenia; however, the findings have not been consistent. This study aims to examine the association of AKT1 polymorphisms with drug-free and post-treatment symptomatology and social function in patients with schizophrenia. One hundred and twenty newly hospitalised patients with acutely exacerbated schizophrenia who had never been treated by atypical antipsychotics were recruited. They received optimal treatment of risperidone for up to 42 days in the inpatient research unit. Clinical manifestations were monitored by Positive and Negative Syndrome Scale (PANSS) and social function by Nurses' Observation Scale for Inpatients Evaluation (NOSIE). Patients were genotyped for eight AKT1 Single Nucleotide Polymorphism (SNPs), which have been previously investigated for association with schizophrenia. At drug-free status and after best possible treatment of risperidone, genotypes of each SNP did not influence performances in NOSIE, PANSS-total, -positive, -negative and -general psychopathology profiles. These results suggest that AKT1 does not play a significant role in clinical and functional manifestations in patients with schizophrenia who receive risperidone treatment. Future research should also focus on the relationships between genotypes of other susceptibility genes and phenotypes or functional outcomes of schizophrenia.