Risk Factors for High Symptom Burden Three Months after Traumatic Brain Injury and Implications for Clinical Trial Design: A Transforming Research and Clinical Knowledge in Traumatic Brain Injury Study

More than 75% of patients presenting to level I trauma centers in the United States with suspicion of TBI sufficient to require a clinical computed tomography scan report injury-related symptoms 3 months later. There are currently no approved treatments, and few clinical trials have evaluated possible treatments. Efficient trials will require subject inclusion and exclusion criteria that balance cost-effective recruitment with enrolling individuals with a higher chance of benefiting from the interventions. Using data from the Transforming Research and Clinical Knowledge in Traumatic Brain Injury (TRACK-TBI) study, we examined the relationship of 3-month symptoms to pre-injury, demographic, and acute characteristics as well as 2-week symptoms and blood-based biomarkers to identify and evaluate factors that may be used for sample enrichment for clinical trials. Many of the risk factors for TBI symptoms reported in the literature were supported, but the effect sizes of each were small or moderate (< 0.5). The only factors with large effect sizes when predicting 3-month symptom burden were TBI-related (i.e., post-concussive) and post-traumatic stress symptom levels at 2 weeks (respective effect sizes 1.13 and 1.34). TBI severity was not significantly associated with 3-month symptom burden (p = 0.37). Using simulated data to evaluate the effect of enrichment, we showed that including only people with high symptom burden at 2 weeks would permit trials to reduce the sample size by half, with minimal increase in screening, as compared with enrolling an unenriched sample. Clinical trials aimed at reducing symptoms after TBI can be efficiently conducted by enriching the included sample with people reporting a high early symptom burden.

Microfluidic Sampling and Biosensing Systems for Foodborne Escherichia coli and Salmonella

Developments of portable biosensors for field-deployable detections have been increasingly important to control foodborne pathogens in regulatory environment and in early stage of outbreaks. Conventional cultivation and gene amplification methods require sophisticated instruments and highly skilled professionals; while portable biosensing devices provide more freedom for rapid detections not only in research laboratories but also in the field; however, their sensitivity and specificity are limited. Microfluidic methods have the advantage of miniaturizing instrumental size while integrating multiple functions and high-throughput capability into one streamlined system at low cost. Minimal sample consumption is another advantage to detect samples in different sizes and concentrations, which is important for the close monitoring of pathogens at consumer end. They improve measurement or manipulation of bacteria by increasing the ratio of functional interface of the device to the targeted biospecies and in turn reducing background interference. This article introduces the major active and passive microfluidic devices that have been used for bacteria sampling and biosensing. The emphasis is on particle-based sorting/enrichment methods with or without external physical fields applied to the microfluidic devices and on various biosensing applications reported for bacteria sampling. Three major fabrication methods for microfluidics are briefly discussed with their advantages and limitations. The applications of these active and passive microfluidic sampling methods in the past 5 years have been summarized, with the focus on Escherichia coli and Salmonella. The current challenges to microfluidic bacteria sampling are caused by the small size and nonspherical shape of various bacterial cells, which can induce unpredictable deviations in sampling and biosensing processes. Future studies are needed to develop rapid prototyping methods for device manufacturing, which can facilitate rapid response to various foodborne pathogen outbreaks.

Ketoenamine Covalent Organic Framework Coating for Efficient Solid-Phase Microextraction of Trace Organochlorine Pesticides

Fiber coating is a key part of solid-phase microextraction (SPME) technology, and it determines the selectivity, sensitivity, and reproducibility of the analytical method. A ketoenamine covalent organic framework called Tp-Azo-COF with rich electronegative N atoms was prepared as an SPME coating in this work. The Tp-Azo-COF coating had a large surface area of 1218 m² g^-1 and good thermal and chemical stability, and it was applied for the extraction of organochlorine pesticides (OCPs). According to quantum chemistry calculations, the adsorption affinity of the Tp-Azo-COF coating for five OCPs was primarily affected by the halogen bond and hydrophobicity interaction. The extraction efficiencies of the Tp-Azo-COF coating for five OCPs were higher than those of three commercial SPME fiber coatings, and the enrichment factors ranged from 1061 to 3693. When combined with gas chromatography-tandem mass spectrometry, a wide linear range (0.1-1000 ng L^-1), low limits of detection (0.002-0.08 ng L^-1), and good fiber-to-fiber accuracy (4.3-10.9%) were achieved under optimal conditions. Moreover, the applicability of the developed method was evaluated by analyzing four samples (milk, green tea, tap water, and well water), and the recoveries were in the range of 83.4-101.6%, with relative standard deviations <8.6%. This research extends the application of the stabilized ketoenamine COF as a sample enrichment probe for OCP analysis.

Nanophotonic Cell Lysis and Polymerase Chain Reaction with Gravity-Driven Cell Enrichment for Rapid Detection of Pathogens

Rapid and precise detection of pathogens is a critical step in the prevention and identification of emergencies related to health and biosafety as well as the clinical management of community-acquired urinary tract infections or sexually transmitted diseases. However, a conventional culture-based pathogen diagnostic method is time-consuming, permitting physicians to use antibiotics without ample clinical data. Here, we present a nanophotonic Light-driven Integrated cell lysis and polymerase chain reaction (PCR) on a chip with Gravity-driven cell enrichment Health Technology (LIGHT) for rapid precision detection of pathogens (<20 min). We created the LIGHT, which has the three functions of (1) selective enrichment of pathogens, (2) photothermal cell lysis, and (3) photonic PCR on a chip. We designed the gravity-driven cell enrichment via a nanoporous membrane on a chip that allows an effective bacterial enrichment of 40 000-fold from a 1 mL sample in 2 min. We established a light-driven photothermal lysis of preconcentrated bacteria within 1 min by designing the network of nanoplasmonic optical antenna on a chip for ultrafast light-to-heat conversion, created the nanoplasmonic optical antenna network-based ultrafast photonic PCR on a chip, and identified Escherichia coli. Finally, we demonstrated the end-point detection of up to 10³ CFU/mL of E. coli in 10 min. We believe that our nanophotonic LIGHT will provide rapid and precise identification of pathogens in both developing and developed countries.

Construction of Fe3O4/Vancomycin/PEG Magnetic Nanocarrier for Highly Efficient Pathogen Enrichment and Gene Sensing

Infectious diseases, especially pathogenic bacterial infections, pose a growing threat to public health worldwide. As pathogenic bacteria usually exist in complex experimental matrixes at very low concentrations, developing a technology for rapid and biocompatible sample enrichment is essential for sensitive diagnosis. In this study, an Fe3O4/Vancomycin/PEG magnetic nanocarrier was constructed for efficient sample enrichment and in situ nucleic acid preparation of pathogenic bacteria for subsequent gene sensing. We attached Vancomycin, a well-known broad-spectrum antibiotic, to the surface of Fe3O4 nanoparticles as a universal molecular probe to target bacterial cells. Polyethylene glycol (PEG) was introduced to enhance the nanocarrier's water solubility and biocompatibility. Results show that the proposed nanocarrier achieved a 90% capture efficiency even if at a Listeria monocytogenes concentration of 1×10(2) cfu/mL. Contributing to the good water solubility achieved by the employment of modified PEG, highly efficient enrichment (enrichment factor 10 times higher than PEG-free nanocarrier) can be completed in 30 min. Moreover, PEG would also develop the nanoparticles' biocompatibility by passivating the positively charged unreacted amines on the magnetic nanoparticles, thus helping to release the negatively charged bacterial genome from the nanocarrier/bacteria complexes when an in situ nucleic acids extraction step was executed. The outstanding bacterial capture capability and biocompatibility of this nanocarrier enabled the implementation of a highly sensitive gene-sensing strategy of pathogens. By employing an electrochemiluminescence-based gene-sensing assay, L. monocytogenes can be rapidly detected with a limit of detection of 10 cfu/mL, which shows great potential for clinical applications.

A density-based proteomics sample fractionation technology: folate deficiency induced oxidative stress response in liver and brain

Folate deficiency (FD) alters hepatic methionine metabolism and is associated with increased hepatocellular apoptosis. Additionally, mice deprived of folate showed increased oxidative damage in brain tissue, leading to cognitive impairment. Most previous studies have focused independently on either liver, the main tissue of folate storage and metabolism, or brain, where folate regulates neurogenesis and programs cell death. The aim of this study was to apply a powerful, rapid proteomics approach to understand potential subcellular correlations of folate deficiency in both brain and liver of the same rat. This approach combined a new density-based sample fractionation technology (enhanced density gradient extraction = Edge technology) with other conventional proteomics techniques, such as western blot analysis, 2DE, and mass spectrometry. The brain and the liver from individual rats, fed normal or FD diets for 6 wks, were homogenized and then fractionated using the Edge 200 Separation System. Subsequently, all fractions from brain and liver, from control and treated rats, were analyzed by western blot using two markers of oxidative stress: glutathione peroxidase 1 (GPx1) and glucose-regulated protein 75 (GRP75). certain fractions were selected based on western blot analysis and were further analyzed by 2DE. protein spots of interest were identified by MALDI-TOF/TOF. The results demonstrated that edge technology provides a powerful density based separation and enrichment method for rapid screening of potential FD markers and their possible correlations to both liver and brain diseases.